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Sample records for inactivated oral cholera

  1. Effectiveness and economic analysis of the whole cell/recombinant B subunit (WC/rbs inactivated oral cholera vaccine in the prevention of traveller's diarrhoea

    Directory of Open Access Journals (Sweden)

    Diez-Diaz Rosa

    2009-05-01

    Full Text Available Abstract Background Nowadays there is a debate about the indication of the oral whole-cell/recombinant B-subunit cholera vaccine (WC/rBS in traveller's diarrhoea. However, a cost-benefit analysis based on real data has not been published. Methods A cost-effectiveness and cost-benefit study of the oral cholera vaccine (WC/rBS, Dukoral® for the prevention of traveller's diarrhoea (TD was performed in subjects travelling to cholera risk areas. The effectiveness of WC/rBS vaccine in the prevention of TD was analyzed in 362 travellers attending two International Vaccination Centres in Spain between May and September 2005. Results The overall vaccine efficacy against TD was 42,6%. Direct healthcare-related costs as well as indirect costs (lost vacation days subsequent to the disease were considered. Preventive vaccination against TD resulted in a mean saving of 79.26 € per traveller. Conclusion According to the cost-benefit analysis performed, the recommendation for WC/rBS vaccination in subjects travelling to zones at risk of TD is beneficial for the traveller, regardless of trip duration and visited continent.

  2. Stimulation of mucosal immune response following oral administration of enterotoxigenic Escherichia coli fimbriae (CFA/I) entrapped in liposomes in conjunction with inactivated whole-cell Vibrio cholerae vaccine.

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    Dima, V F; Ionescu, M D; Palade, R; Balotescu, C; Becheanu, G; Dima, S V

    2001-01-01

    In this study, we have searched for an effective mucosal vaccine. An oral enterotoxigenic E. coli vaccine containing colonization factor antigen (CFA/I) associated with inactivated whole-cell V. cholerae vaccine (WCV) has been tested for safety and immunogenicity in animals. Five groups of animals were used. The results showed the following: (a) vaccine containing CFA/I antigen entrapped in liposomes and associated with WCV (batch C) had increased titers of specific antibodies to CFA/I antigen in 15 to 18 (83.3%) animals; (b) specific Peyer's patches (PP), lymph nodes (LN) and spleen (SPL) lymphocytes proliferation was detected following in vitro restimulation with CFA/I antigen or WCV. This response gradually increased to the highest value by the 35th postimmunization day. Moreover, lower PP, LN and spleen (SPL) proliferation was observed in rabbits receiving soluble CFA/I antigen (S-CFA/I) or free liposomes (F-L) alone; (c) adhesion of E. coli H10407 strain labelled with 3H-leucine in immunized and control animals revealed the following local effects: (i) protection of rabbit intestinal mucosa against virulent E. coli cells; (ii) inhibition of adhesion of ETEC bacteria to intestinal mucosa and (iii) significantly faster release of E. coli H 10407 strain labelled with 3H-leucine from the intestinal tract of immunized animals. The histopathological and electron microscope findings confirmed the above results. The experimental results point out an efficient protection against infection with E. coli strains (ETEC), after mucosal vaccination with CFA/I antigen entrapped in liposomes associated with inactivated whole-cell Vibrio cholerae as immunological adjuvant.

  3. Cost-effectiveness of oral cholera vaccine in a stable refugee population at risk for epidemic cholera and in a population with endemic cholera.

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    Murray, J.; McFarland, D. A.; Waldman, R. J.

    1998-01-01

    Recent large epidemics of cholera with high incidence and associated mortality among refugees have raised the question of whether oral cholera vaccines should be considered as an additional preventive measure in high-risk populations. The potential impact of oral cholera vaccines on populations prone to seasonal endemic cholera has also been questioned. This article reviews the potential cost-effectiveness of B-subunit, killed whole-cell (BS-WC) oral cholera vaccine in a stable refugee popula...

  4. Impact of oral cholera vaccines in cholera-endemic countries: A mathematical modeling study.

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    Kim, Jong-Hoon; Mogasale, Vittal; Burgess, Colleen; Wierzba, Thomas F

    2016-04-19

    Impact evaluation of vaccination programs is necessary for making decisions to introduce oral cholera vaccines (OCVs) in cholera-endemic countries. We analyzed data to forecast the future global burden of cholera. We developed a mathematical model of cholera transmission in three countries as examples: Nigeria, Uganda, and Indonesia. After fitting the model, we evaluated the impact of OCVs delivered in four vaccination strategies varying by target age group and frequency of vaccination over the period of 2015-2030. Data suggest that the global annual incidence of cholera will increase from 3046238 in 2015 to 3787385 in 2030 with the highest burden in Asia and Africa where overall population size is large and the proportion of population with access to improved sanitation facilities is low. We estimate that OCV will reduce the cumulative incidence of cholera by half in Indonesia and >80% in Nigeria and Uganda when delivered to 1+ year olds every three years at a coverage rate of 50%, although cholera may persist through higher coverage rates (i.e., >90%). The proportion of person-to-person transmission compared to water-to-person transmission is positively correlated with higher vaccination impact in all three countries. Periodic OCV vaccination every three or five years can significantly reduce the global burden of cholera although cholera may persist even with high OCV coverage. Vaccination impact will likely vary depending on local epidemiological conditions including age distribution of cases and relative contribution of different transmission routes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Killed oral cholera vaccines: history, development and implementation challenges.

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    Lopez, Anna Lena; Gonzales, Maria Liza Antoinette; Aldaba, Josephine G; Nair, G Balakrish

    2014-09-01

    Cholera is still a major global health problem, affecting mainly people living in unsanitary conditions and who are at risk for outbreaks of cholera. During the past decade, outbreaks are increasingly reported from more countries. From the early killed oral cholera vaccine, rapid improvements in vaccine development occurred as a result of a better understanding of the epidemiology of the disease, pathogenesis of cholera infection and immunity. The newer-generation oral killed cholera vaccines have been shown to be safe and effective in field trials conducted in cholera endemic areas. Likewise, they have been shown to be protective when used during outbreak settings. Aside from providing direct protection to vaccinated individuals, recent studies have demonstrated that these killed oral vaccines also confer indirect protection through herd immunity. Although new-generation oral cholera vaccines should not be considered in isolation from other preventive approaches in countries where they are most needed, especially improved water quality and sanitation, these vaccines serve as immediately available public health tools for preventing further morbidity and mortality from cholera. However, despite its availability for more than two decades, use of these vaccines has not been optimized. Although there are limitations of the currently available oral cholera vaccines, recent data show that the vaccines are safe, feasible to use even in difficult circumstances and able to provide protection in various settings. Clear identification of the areas and target population groups who will benefit from the use of the cholera vaccines will be required and strategies to facilitate accessibility and usage of these vaccines in these areas and population groups will need to be developed.

  6. Critical Analysis of Compositions and Protective Efficacies of Oral Killed Cholera Vaccines

    Science.gov (United States)

    2014-01-01

    Two cholera vaccines, sold as Shanchol and Dukoral, are currently available. This review presents a critical analysis of the protective efficacies of these vaccines. Children under 5 years of age are very vulnerable to cholera and account for the highest incidence of cholera cases and more than half of the resulting deaths. Both Shanchol and Dukoral are two-spaced-dose oral vaccines comprising large numbers of killed cholera bacteria. The former contains Vibrio cholerae O1 and O139 cells, and the latter contains V. cholerae O1 cells with the recombinant B subunit of cholera toxin. In a field trial in Kolkata (India), Shanchol, the preferred vaccine, protected 45% of the test subjects in all of the age groups and only 17% of the children under 5 years of age during the first year of surveillance. In a field trial in Peru, two spaced doses of Dukoral offered negative protection in children under 5 years of age and little protection (15%) in vaccinees over 6 years of age during the first year of surveillance. Little is known about Dukoral's long-term protective efficacy. Both of these vaccines have questionable compositions, using V. cholerae O1 strains isolated in 1947 that have been inactivated by heat and formalin treatments that may denature protein. Immunological studies revealed Dukoral's reduced and short-lived efficacy, as measured by several immunological endpoints. Various factors, such as the necessity for multiple doses, poor protection of children under 5 years of age, the requirement of a cold supply chain, production costs, and complex logistics of vaccine delivery, greatly reduce the suitability of either of these vaccines for endemic or epidemic cholera control in resource-poor settings. PMID:25056361

  7. Vaxchora: A Single-Dose Oral Cholera Vaccine.

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    Cabrera, Adriana; Lepage, Jayne E; Sullivan, Karyn M; Seed, Sheila M

    2017-07-01

    To review trials evaluating the efficacy and safety of Vaxchora, a reformulated, single-dose, oral, lyophilized Vibrio cholerae CVD 103-HgR vaccine for the prevention of travel-related cholera caused by V cholerae serogroup O1. A literature search was conducted using MEDLINE (1946 to January week 3, 2017) and EMBASE (1996 to 2017 week 3). Keywords included oral cholera vaccine, single-dose, Vaxchora, and CVD 103-HgR. Limits included human, clinical trials published in English since 2010. ClinicalTrials.gov was used as a source for unpublished data. Additional data sources were obtained through bibliographic review of selected articles. Studies that addressed the safety and efficacy of Vaxchora, the reformulated, single-dose oral CVD 103-HgR cholera vaccine, were selected for analysis. Approval of Vaxchora, was based on efficacy of the vaccine in human trials demonstrating 90.3% protection among those challenged with V cholerae 10 days after vaccination and in immunogenicity studies with 90% systemic vibriocidal antibody conversion at 6 months after a single-dose of vaccine. Tolerability was acceptable, with the most common adverse effects reported to be fatigue, headache, and abdominal pain. Vaxchora is the only FDA-approved, single-dose oral vaccine for the prevention of cholera caused by V cholerae serogroup O1 in adult travelers from the United States going to cholera-affected areas. Safety and efficacy has not been established in children, immunocompromised persons, and pregnant or breastfeeding women or those living in cholera-endemic areas.

  8. Use of oral cholera vaccine as a vaccine probe to define the geographical dimensions of person-to-person transmission of cholera.

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    Ali, Mohammad; Kim, Deok Ryun; Kanungo, Suman; Sur, Dipika; Manna, Byomkesh; Digilio, Laura; Dutta, Shanta; Marks, Florian; Bhattacharya, Sujit K; Clemens, John

    2018-01-01

    Cholera is known to be transmitted from person to person, and inactivated oral cholera vaccines (OCVs) have been shown to confer herd protection via interruption of this transmission. However, the geographic dimensions of chains of person-to-person transmission of cholera are uncertain. The ability of OCVs to confer herd protection was used to define these dimensions in two cholera-endemic settings, one in rural Bangladesh and the other in urban India. Two large randomized, placebo-controlled trials of inactivated OCVs, one in rural Matlab, Bangladesh and the other in urban Kolkata, India, were reanalyzed. Vaccine herd protection was evaluated by relating the risk of cholera in placebo recipients to vaccine coverage of surrounding residents residing within concentric rings. In Matlab, concentric rings in 100-m increments up to 700m were evaluated; in Kolkata, 50-m increments up to 350m were evaluated. One hundred and eight cholera cases among 24667 placebo recipients were detected during 1year of post-vaccination follow-up at Matlab; 128 cholera cases among 34968 placebo recipients were detected during 3 years of follow-up in Kolkata. Consistent inverse relationships were observed between vaccine coverage of the ring and the risk of cholera in the central placebo recipient for rings with radii up to 500m in Matlab and up to 150m in Kolkata. These results suggest that the dimensions of chains of person-to-person transmission in endemic settings can be quite large and may differ substantially from setting to setting. Using OCVs as 'probes' to define these dimensions can inform geographical targeting strategies for the deployment of these vaccines in endemic settings. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  9. Oral cholera vaccine--for whom, when, and why?

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    Topps, Maureen H

    2006-01-01

    The search for a safe, effective, well tolerated, low cost vaccine against the ancient cholera enemy has been ongoing since the 19th century and has been revitalized in the past two decades since the advent of recombinant technology. Large-scale field trials have readily demonstrated the tolerability and safety of oral cholera vaccine in various forms. Variable levels of protection have been shown and one challenge has been to demonstrate whether this is a cost effective treatment in differing environments including its use in endemic and epidemic areas as well as for travelers. A review of recent literature was undertaken to assess the effectiveness and uses of currently available oral cholera vaccine. While the evidence does not support the creation of formal guidelines, some clear recommendations can be made. There is undoubtedly the potential to reduce the burden of illness both in endemic and epidemic situations. For travelers, certain higher risk groups may benefit from protection against cholera. More significantly, the short term cross-protection afforded by whole cell, B subunit (WC BS) oral cholera vaccine formulations against enterotoxigenic E. coli, (ETEC), the commonest causative agent of traveler's diarrhoea, may prove to be the most important raison d'être.

  10. Ultraviolet inactivation and photoreactivation of the cholera phage 'Kappa'

    International Nuclear Information System (INIS)

    Samad, S.A.; Bhattacharyya, S.C.; Chatterjee, S.N.

    1987-01-01

    The lysogenic cholera phage, 'Kappa' is some ten to twenty folds more resistant to UV (254 nm) than are most of the T. phages of E. coli, or the cholera phage PL 163/10, or the host V. cholerae strain H218 Sm r , the 37% (D 37 ) and 10% (D 10 ) survival doses being 255.8 J/m 2 and 633.6 J/m 2 respectively. The UV-irradiated 'Kappa' phages could be photoreactivated in the host V. cholerae strain H218 Sm r to a maximum extent of 40%. The removal of the number of lethal hits per phage by the survival-enhancement treatment (photoreactivation) with time followed an exponential relation, the constant probability of removal of lethal hit per unit time being 2.8x10 -2 min -1 . The UV-irradiated phages could also be Weigle reactivated in the host strain of H218 Sm r by a small degree, the maximum reactivation factor (ratio of survivals in UV-irradiated and non-irradiated hosts) being 1.50. (orig.)

  11. Reduction of travellers' diarrhoea by WC/rBS oral cholera vaccine in young, high-risk travellers.

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    Torrell, Josep Ma Ramon; Aumatell, Cristina Masuet; Ramos, Sergi Morchon; Mestre, Laura Gavaldà; Salas, Carme Micheo

    2009-06-19

    A bidirectional cohort study investigates whether pre-travel vaccination with whole cell/recombinant B subunit inactivated, killed oral cholera vaccine reduces the incidence of diarrhoea in young adult travellers to high-risk areas. Risk of travellers' diarrhoea was assessed according to destination and reason for travel in high-risk travellers of a travel clinic in Barcelona, Spain. Those at high-risk between January and December 2005 were advised on water/food safety and hygiene. High-risk travellers between January and December 2006 were additionally vaccinated with WC/rBS oral cholera vaccine. Data regarding diarrhoea were gathered by structured telephone interview or e-mailed questionnaire following the travellers' return. The incidence of diarrhoea in the group vaccinated with WC/rBS oral cholera vaccine (n=321) was 17.4%, compared with 39.7% in the non-vaccinated group (n=337) (adjusted risk ratio 0.40). The first episode was significantly shorter in the vaccinated group (mean 2.3 days) than in the non-vaccinated group (mean 3.8 days) (pyoung, high-risk travellers. Vaccination with the WC/rBS oral cholera vaccine as well as food safety and hygiene advice could offer effective means of reducing the risk of diarrhoea while abroad.

  12. Effectiveness of reactive oral cholera vaccination in rural Haiti: a case-control study and bias-indicator analysis.

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    Ivers, Louise C; Hilaire, Isabelle J; Teng, Jessica E; Almazor, Charles P; Jerome, J Gregory; Ternier, Ralph; Boncy, Jacques; Buteau, Josiane; Murray, Megan B; Harris, Jason B; Franke, Molly F

    2015-03-01

    Between April and June, 2012, a reactive cholera vaccination campaign was done in Haiti with an oral inactivated bivalent whole-cell vaccine. We aimed to assess the effectiveness of the vaccine in a case-control study and to assess the likelihood of bias in that study in a bias-indicator study. Residents of Bocozel or Grand Saline who were eligible for the vaccination campaign (ie, age ≥12 months, not pregnant, and living in the region at the time of the vaccine campaign) were included. In the primary case-control study, cases had acute watery diarrhoea, sought treatment at one of three participating cholera treatment units, and had a stool sample positive for cholera by culture. For each case, four control individuals who did not seek treatment for acute watery diarrhoea were matched by location of residence, enrolment time (within 2 weeks of the case), and age (1-4 years, 5-15 years, and >15 years). Cases in the bias-indicator study were individuals with acute watery diarrhoea with a negative stool sample for cholera. Controls were selected in the same manner as in the primary case-control study. Trained staff used standard laboratory procedures to do rapid tests and stool cultures from study cases. Participants were interviewed to collect data on sociodemographic characteristics, risk factors for cholera, and self-reported vaccination. Data were analysed by conditional logistic regression, adjusting for matching factors. From Oct 24, 2012, to March 9, 2014, 114 eligible individuals presented with acute watery diarrhoea and were enrolled, 25 of whom were subsequently excluded. 47 participants were analysed as cases in the vaccine effectiveness case-control study and 42 as cases in the bias-indicator study. 33 (70%) of 47 cholera cases self-reported vaccination versus 167 (89%) of 188 controls (vaccine effectiveness 63%, 95% CI 8-85). 27 (57%) of 47 cases had certified vaccination versus 147 (78%) of 188 controls (vaccine effectiveness 58%, 13-80). Neither self

  13. Cholera

    Science.gov (United States)

    ... causes a large amount of watery diarrhea. Causes Cholera is caused by the bacterium Vibrio cholerae . These bacteria release a toxin that causes an ... include: Africa Some parts of Asia India Bangladesh Mexico South and Central America ... Symptoms of cholera can be mild to severe. They include: Abdominal ...

  14. From Cholera to Burns: A Role for Oral Rehydration Therapy

    Science.gov (United States)

    Green, W.B.; Asuku, M.E.; Feldman, M.; Makam, R.; Noppenberger, D.; Price, L.A.; Prosciak, M.; van Loon, I.N.

    2011-01-01

    According to the practice guidelines of the American Burn Association on burn shock resuscitation, intravenous (IV) fluid therapy is the standard of care for the replacement of fluid and electrolyte losses in burn injury of ≥20% of the total body surface area. However, in mass burn casualties, IV fluid resuscitation may be delayed or unavailable. Oral rehydration therapy (ORT), which has been shown to be highly effective in the treatment of dehydration in epidemics of cholera, could be an alternate way to replace fluid losses in burns. A prospective case series of three patients was carried out as an initial step to establish whether oral Ceralyte®90 could replace fluid losses requiring IV fluid therapy in thermal injury. The requirement of the continuing IV fluid therapy was reduced by an average of 58% in the first 24 hours after the injury (range 37-78%). ORT may be a feasible alternative to IV fluid therapy in the resuscitation of burns. It could also potentially save many lives in mass casualty situations or in resource-poor settings where IV fluid therapy is not immediately available. Further studies are needed to assess the efficacy of this treatment and to determine whether the present formulations of ORT for cholera need modification. PMID:22283039

  15. Effectiveness of an oral cholera vaccine campaign to prevent clinically-significant cholera in Odisha State, India.

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    Wierzba, Thomas F; Kar, Shantanu K; Mogasale, Vijayalaxmi V; Kerketta, Anna S; You, Young Ae; Baral, Prameela; Khuntia, Hemant K; Ali, Mohammad; Kim, Yang Hee; Rath, Shyam Bandhu; Bhattachan, Anuj; Sah, Binod

    2015-05-15

    A clinical trial conducted in India suggests that the oral cholera vaccine, Shanchol, provides 65% protection over five years against clinically-significant cholera. Although the vaccine is efficacious when tested in an experimental setting, policymakers are more likely to use this vaccine after receiving evidence demonstrating protection when delivered to communities using local health department staff, cold chain equipment, and logistics. We used a test-negative, case-control design to evaluate the effectiveness of a vaccination campaign using Shanchol and validated the results using a cohort approach that addressed disparities in healthcare seeking behavior. The campaign was conducted by the local health department using existing resources in a cholera-endemic area of Puri District, Odisha State, India. All non-pregnant residents one year of age and older were offered vaccine. Over the next two years, residents seeking care for diarrhea at one of five health facilities were asked to enroll following informed consent. Cases were patients seeking treatment for laboratory-confirmed V. cholera-associated diarrhea. Controls were patients seeking treatment for V. cholerae negative diarrhea. Of 51,488 eligible residents, 31,552 individuals received one dose and 23,751 residents received two vaccine doses. We identified 44 V. cholerae O1-associated cases and 366 non V. cholerae diarrhea controls. The adjusted protective effectiveness for persons receiving two doses was 69.0% (95% CI: 14.5% to 88.8%), which is similar to the adjusted estimates obtained from the cohort approach. A statistical trend test suggested a single dose provided a modicum of protection (33%, test for trend, p=0.0091). This vaccine was found to be as efficacious as the results reported from a clinical trial when administered to a rural population using local health personnel and resources. This study provides evidence that this vaccine should be widely deployed by public health departments in

  16. A retrospective analysis of oral cholera vaccine use, disease severity and deaths during an outbreak in South Sudan

    NARCIS (Netherlands)

    Bekolo, C.E.; Loenhout, J.A. van; Rodriguez-Llanes, J.M.; Rumunu, J.; Ramadan, O.P.; Guha-Sapir, D.

    2016-01-01

    OBJECTIVE: To determine whether pre-emptive oral cholera vaccination reduces disease severity and mortality in people who develop cholera disease during an outbreak. METHODS: The study involved a retrospective analysis of demographic and clinical data from 41 cholera treatment facilities in South

  17. Comparative effectiveness of different strategies of oral cholera vaccination in bangladesh: a modeling study.

    Directory of Open Access Journals (Sweden)

    Dobromir T Dimitrov

    2014-12-01

    Full Text Available Killed, oral cholera vaccines have proven safe and effective, and several large-scale mass cholera vaccination efforts have demonstrated the feasibility of widespread deployment. This study uses a mathematical model of cholera transmission in Bangladesh to examine the effectiveness of potential vaccination strategies.We developed an age-structured mathematical model of cholera transmission and calibrated it to reproduce the dynamics of cholera in Matlab, Bangladesh. We used the model to predict the effectiveness of different cholera vaccination strategies over a period of 20 years. We explored vaccination programs that targeted one of three increasingly focused age groups (the entire vaccine-eligible population of age one year and older, children of ages 1 to 14 years, or preschoolers of ages 1 to 4 years and that could occur either as campaigns recurring every five years or as continuous ongoing vaccination efforts. Our modeling results suggest that vaccinating 70% of the population would avert 90% of cholera cases in the first year but that campaign and continuous vaccination strategies differ in effectiveness over 20 years. Maintaining 70% coverage of the population would be sufficient to prevent sustained transmission of endemic cholera in Matlab, while vaccinating periodically every five years is less effective. Selectively vaccinating children 1-14 years old would prevent the most cholera cases per vaccine administered in both campaign and continuous strategies.We conclude that continuous mass vaccination would be more effective against endemic cholera than periodic campaigns. Vaccinating children averts more cases per dose than vaccinating all age groups, although vaccinating only children is unlikely to control endemic cholera in Bangladesh. Careful consideration must be made before generalizing these results to other regions.

  18. Comparative effectiveness of different strategies of oral cholera vaccination in bangladesh: a modeling study.

    Science.gov (United States)

    Dimitrov, Dobromir T; Troeger, Christopher; Halloran, M Elizabeth; Longini, Ira M; Chao, Dennis L

    2014-12-01

    Killed, oral cholera vaccines have proven safe and effective, and several large-scale mass cholera vaccination efforts have demonstrated the feasibility of widespread deployment. This study uses a mathematical model of cholera transmission in Bangladesh to examine the effectiveness of potential vaccination strategies. We developed an age-structured mathematical model of cholera transmission and calibrated it to reproduce the dynamics of cholera in Matlab, Bangladesh. We used the model to predict the effectiveness of different cholera vaccination strategies over a period of 20 years. We explored vaccination programs that targeted one of three increasingly focused age groups (the entire vaccine-eligible population of age one year and older, children of ages 1 to 14 years, or preschoolers of ages 1 to 4 years) and that could occur either as campaigns recurring every five years or as continuous ongoing vaccination efforts. Our modeling results suggest that vaccinating 70% of the population would avert 90% of cholera cases in the first year but that campaign and continuous vaccination strategies differ in effectiveness over 20 years. Maintaining 70% coverage of the population would be sufficient to prevent sustained transmission of endemic cholera in Matlab, while vaccinating periodically every five years is less effective. Selectively vaccinating children 1-14 years old would prevent the most cholera cases per vaccine administered in both campaign and continuous strategies. We conclude that continuous mass vaccination would be more effective against endemic cholera than periodic campaigns. Vaccinating children averts more cases per dose than vaccinating all age groups, although vaccinating only children is unlikely to control endemic cholera in Bangladesh. Careful consideration must be made before generalizing these results to other regions.

  19. Successful comeback of the single-dose live oral cholera vaccine CVD 103-HgR.

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    Herzog, Christian

    2016-01-01

    Effective and easy to administer cholera vaccines are in need more than ever, for at risk populations and travellers alike. In many parts of the world cholera is still endemic, causing outbreaks and constituting repeatedly serious public health problems. The oral live cholera vaccine CVD 103-HgR (Orochol, Mutachol), the first genetically modified organism (GMO) used as vaccine, was in its time (launched 1993, Switzerland) the ideal cholera vaccine: single-dose, protective efficacy of 80-100% against moderate to severe cholera, acting within 8 days and exhibiting excellent safety, indiscernible from placebo. However, there were strong headwinds: In the 1990s the indication for cholera vaccines was generally downplayed by experts and in 1997 the European Commission called for a moratorium of GMOs which blocked the registration in the European Union. Thus, demand for this vaccine remained low and in 2003 it was taken off the market for economic reasons. After a decade in obscurity it (Vaxchora) has resurfaced again, now produced in the U.S. and equipped with a U.S. FDA license (June 10, 2016). What had happened? This commentary gives a critical account of an almost unbelievable string of misadventures, emerging adverse circumstances and man-made failures which nearly killed this single-dose live oral cholera vaccine. The good news is that patience and persistence lead to success in the end, allowing good science to prevail for the benefit of those in need. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Maximizing protection from use of oral cholera vaccines in developing country settings

    Science.gov (United States)

    Desai, Sachin N; Cravioto, Alejandro; Sur, Dipika; Kanungo, Suman

    2014-01-01

    When oral vaccines are administered to children in lower- and middle-income countries, they do not induce the same immune responses as they do in developed countries. Although not completely understood, reasons for this finding include maternal antibody interference, mucosal pathology secondary to infection, malnutrition, enteropathy, and previous exposure to the organism (or related organisms). Young children experience a high burden of cholera infection, which can lead to severe acute dehydrating diarrhea and substantial mortality and morbidity. Oral cholera vaccines show variations in their duration of protection and efficacy between children and adults. Evaluating innate and memory immune response is necessary to understand V. cholerae immunity and to improve current cholera vaccine candidates, especially in young children. Further research on the benefits of supplementary interventions and delivery schedules may also improve immunization strategies. PMID:24861554

  1. Antibody Secreting Cell Responses following Vaccination with Bivalent Oral Cholera Vaccine among Haitian Adults.

    Directory of Open Access Journals (Sweden)

    Wilfredo R Matias

    2016-06-01

    Full Text Available The bivalent whole-cell (BivWC oral cholera vaccine (Shanchol is effective in preventing cholera. However, evaluations of immune responses following vaccination with BivWC have been limited. To determine whether BivWC induces significant mucosal immune responses, we measured V. cholerae O1 antigen-specific antibody secreting cell (ASC responses following vaccination.We enrolled 24 Haitian adults in this study, and administered doses of oral BivWC vaccine 14 days apart (day 0 and day 14. We drew blood at baseline, and 7 days following each vaccine dose (day 7 and 21. Peripheral blood mononuclear cells (PBMCs were isolated, and ASCs were enumerated using an ELISPOT assay. Significant increases in Ogawa (6.9 cells per million PBMCs and Inaba (9.5 cells per million PBMCs OSP-specific IgA ASCs were detected 7 days following the first dose (P < 0.001, but not the second dose. The magnitude of V. cholerae-specific ASC responses did not appear to be associated with recent exposure to cholera. ASC responses measured against the whole lipolysaccharide (LPS antigen and the OSP moiety of LPS were equivalent, suggesting that all or nearly all of the LPS response targets the OSP moiety.Immunization with the BivWC oral cholera vaccine induced ASC responses among a cohort of healthy adults in Haiti after a single dose. The second dose of vaccine resulted in minimal ASC responses over baseline, suggesting that the current dosing schedule may not be optimal for boosting mucosal immune responses to V. cholerae antigens for adults in a cholera-endemic area.

  2. Implementation research: reactive mass vaccination with single-dose oral cholera vaccine, Zambia.

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    Poncin, Marc; Zulu, Gideon; Voute, Caroline; Ferreras, Eva; Muleya, Clara Mbwili; Malama, Kennedy; Pezzoli, Lorenzo; Mufunda, Jacob; Robert, Hugues; Uzzeni, Florent; Luquero, Francisco J; Chizema, Elizabeth; Ciglenecki, Iza

    2018-02-01

    To describe the implementation and feasibility of an innovative mass vaccination strategy - based on single-dose oral cholera vaccine - to curb a cholera epidemic in a large urban setting. In April 2016, in the early stages of a cholera outbreak in Lusaka, Zambia, the health ministry collaborated with Médecins Sans Frontières and the World Health Organization in organizing a mass vaccination campaign, based on single-dose oral cholera vaccine. Over a period of 17 days, partners mobilized 1700 health ministry staff and community volunteers for community sensitization, social mobilization and vaccination activities in 10 townships. On each day, doses of vaccine were delivered to vaccination sites and administrative coverage was estimated. Overall, vaccination teams administered 424 100 doses of vaccine to an estimated target population of 578 043, resulting in an estimated administrative coverage of 73.4%. After the campaign, few cholera cases were reported and there was no evidence of the disease spreading within the vaccinated areas. The total cost of the campaign - 2.31 United States dollars (US$) per dose - included the relatively low cost of local delivery - US$ 0.41 per dose. We found that an early and large-scale targeted reactive campaign using a single-dose oral vaccine, organized in response to a cholera epidemic within a large city, to be feasible and appeared effective. While cholera vaccines remain in short supply, the maximization of the number of vaccines in response to a cholera epidemic, by the use of just one dose per member of an at-risk community, should be considered.

  3. Knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among urban high-risk groups: findings of a cross-sectional study in Dhaka, Bangladesh

    Science.gov (United States)

    2013-01-01

    Background In endemic countries such as Bangladesh, consequences of cholera place an enormous financial and social burden on patients and their families. Cholera vaccines not only provide health benefits to susceptible populations but also have effects on the earning capabilities and financial stability of the family. Community-based research and evaluations are necessary to understand perceptions about and practices of the community relating to cholera and oral cholera vaccines. This may help identify the ways in which such vaccines may be successfully introduced, and other preventive measures can be implemented. The present study assessed the knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among an urban population residing in a high cholera-prone setting in Dhaka, Bangladesh. Methods This cross-sectional study was conducted in an area of high cholera prevalence in 15 randomly-selected clusters in Mirpur, Dhaka city. A study team collected data through a survey and in-depth interviews during December 2010–February 2011. Results Of 2,830 families included in the final analysis, 23% could recognize cholera as acute watery diarrhea and 16% had ever heard of oral cholera vaccine. About 54% of the respondents had poor knowledge about cholera-related issues while 97% had a positive attitude toward cholera and oral cholera vaccine. One-third showed poor practice relating to the prevention of cholera. The findings showed a significant (p cholera were the significant predictors to having poor knowledge. Conclusions The findings suggest the strengthening of health education activities to improve knowledge on cholera, its prevention and treatment and information on cholera vaccination among high-risk populations. The data also underscore the potential of mass cholera vaccination to prevent and control cholera. PMID:23509860

  4. Effectiveness of Oral Cholera Vaccine in Haiti: 37-Month Follow-Up.

    Science.gov (United States)

    Sévère, Karine; Rouzier, Vanessa; Anglade, Stravinsky Benedict; Bertil, Claudin; Joseph, Patrice; Deroncelay, Alexandra; Mabou, Marie Marcelle; Wright, Peter F; Guillaume, Florence Duperval; Pape, Jean William

    2016-05-04

    The first oral cholera vaccine (OCV) campaign, since its prequalification by the World Health Organization, in response to an ongoing cholera epidemic (reactive vaccination) was successfully conducted in a poor urban slum of approximately 70,000 inhabitants in Port-au-Prince, Haiti, in 2012. Vaccine coverage was 75% of the target population. This report documents the impact of OCV in reducing the number of culture-confirmed cases of cholera admitted to the Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes (GHESKIO) cholera treatment center from that community in the 37 months postvaccination (April 2012-April 30, 2015). Of 1,788 patients with culture-confirmed cholera, 1,770 (99%) were either from outside the vaccine area (1,400 cases) or from the vaccinated community who had not received OCV (370 cases). Of the 388 people from the catchment area who developed culture-confirmed cholera, 370 occurred among the 17,643 people who had not been vaccinated (2.1%) and the remaining 18 occurred among the 52,357 people (0.034%) who had been vaccinated (P cholera in outbreak settings. © The American Society of Tropical Medicine and Hygiene.

  5. Oral cholera vaccine use in Zanzibar: socioeconomic and behavioural features affecting demand and acceptance

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    Chaignat Claire-Lise

    2009-04-01

    Full Text Available Abstract Background Cholera remains a serious public health problem in low-income countries despite efforts in the past to promote oral rehydration therapy as major treatment. In 2007, the majority of worldwide cases (94% and deaths (99% were reported from Africa. To improve cholera control efforts in addition to maintaining and improving existing water supply, sanitation and hygiene behaviour measures, the World Health Organization has recently started to consider the use of vaccines as an additional public health tool. To assess this new approach in endemic settings, a project was launched in Zanzibar to vaccinate 50,000 individuals living in communities at high risk of cholera with an oral two-dose vaccine (Dukoral®. Immunisation programmes in low-income countries have suffered a reduced coverage or were even brought to a halt because of an ignorance of local realities. To ensure the success of vaccination campaigns, implementers have to consider community-held perceptions and behaviours regarding the infectious disease and the vaccine of interest. The main aim of this study is to provide advice to the Ministry of Health and Social Welfare of Zanzibar regarding routine introduction of an oral cholera vaccine from a socioeconomic and behavioural perspective as part of a long-term development for a sustained cholera prevention strategy. Methods and design Qualitative and quantitative methods of health social science research will be applied on four stakeholder levels before and after the mass vaccination campaign. Rapid assessment individual interviews and focus groups will be used to describe cholera- and vaccine-related views of policy makers, health care professionals and community representatives. The cultural epidemiological approach will be employed on the individual household resident level in a repeated cross-sectional design to estimate determinants of anticipated and actual oral cholera vaccine acceptance. Discussion The study

  6. Oral cholera vaccine use in Zanzibar: socioeconomic and behavioural features affecting demand and acceptance

    Science.gov (United States)

    Schaetti, Christian; Hutubessy, Raymond; Ali, Said M; Pach, Al; Weiss, Mitchell G; Chaignat, Claire-Lise; Khatib, Ahmed M

    2009-01-01

    Background Cholera remains a serious public health problem in low-income countries despite efforts in the past to promote oral rehydration therapy as major treatment. In 2007, the majority of worldwide cases (94%) and deaths (99%) were reported from Africa. To improve cholera control efforts in addition to maintaining and improving existing water supply, sanitation and hygiene behaviour measures, the World Health Organization has recently started to consider the use of vaccines as an additional public health tool. To assess this new approach in endemic settings, a project was launched in Zanzibar to vaccinate 50,000 individuals living in communities at high risk of cholera with an oral two-dose vaccine (Dukoral®). Immunisation programmes in low-income countries have suffered a reduced coverage or were even brought to a halt because of an ignorance of local realities. To ensure the success of vaccination campaigns, implementers have to consider community-held perceptions and behaviours regarding the infectious disease and the vaccine of interest. The main aim of this study is to provide advice to the Ministry of Health and Social Welfare of Zanzibar regarding routine introduction of an oral cholera vaccine from a socioeconomic and behavioural perspective as part of a long-term development for a sustained cholera prevention strategy. Methods and design Qualitative and quantitative methods of health social science research will be applied on four stakeholder levels before and after the mass vaccination campaign. Rapid assessment individual interviews and focus groups will be used to describe cholera- and vaccine-related views of policy makers, health care professionals and community representatives. The cultural epidemiological approach will be employed on the individual household resident level in a repeated cross-sectional design to estimate determinants of anticipated and actual oral cholera vaccine acceptance. Discussion The study presented here is designed to

  7. Protection against cholera from killed whole-cell oral cholera vaccines: a systematic review and meta-analysis.

    Science.gov (United States)

    Bi, Qifang; Ferreras, Eva; Pezzoli, Lorenzo; Legros, Dominique; Ivers, Louise C; Date, Kashmira; Qadri, Firdausi; Digilio, Laura; Sack, David A; Ali, Mohammad; Lessler, Justin; Luquero, Francisco J; Azman, Andrew S

    2017-10-01

    Killed whole-cell oral cholera vaccines (kOCVs) are becoming a standard cholera control and prevention tool. However, vaccine efficacy and direct effectiveness estimates have varied, with differences in study design, location, follow-up duration, and vaccine composition posing challenges for public health decision making. We did a systematic review and meta-analysis to generate average estimates of kOCV efficacy and direct effectiveness from the available literature. For this systematic review and meta-analysis, we searched PubMed, Embase, Scopus, and the Cochrane Review Library on July 9, 2016, and ISI Web of Science on July 11, 2016, for randomised controlled trials and observational studies that reported estimates of direct protection against medically attended confirmed cholera conferred by kOCVs. We included studies published on any date in English, Spanish, French, or Chinese. We extracted from the published reports the primary efficacy and effectiveness estimates from each study and also estimates according to number of vaccine doses, duration, and age group. The main study outcome was average efficacy and direct effectiveness of two kOCV doses, which we estimated with random-effect models. This study is registered with PROSPERO, number CRD42016048232. Seven trials (with 695 patients with cholera) and six observational studies (217 patients with cholera) met the inclusion criteria, with an average two-dose efficacy of 58% (95% CI 42-69, I 2 =58%) and effectiveness of 76% (62-85, I 2 =0). Average two-dose efficacy in children younger than 5 years (30% [95% CI 15-42], I 2 =0%) was lower than in those 5 years or older (64% [58-70], I 2 =0%; pcholera for at least 3 years. One kOCV dose provides at least short-term protection, which has important implications for outbreak management. kOCVs are effective tools for cholera control. The Bill & Melinda Gates Foundation. Copyright This is an Open Access article published under the CC BY 3.0 IGO license which permits

  8. Use of oral cholera vaccines in an outbreak in Vietnam: a case control study.

    Directory of Open Access Journals (Sweden)

    Dang Duc Anh

    Full Text Available BACKGROUND: Killed oral cholera vaccines (OCVs are available but not used routinely for cholera control except in Vietnam, which produces its own vaccine. In 2007-2008, unprecedented cholera outbreaks occurred in the capital, Hanoi, prompting immunization in two districts. In an outbreak investigation, we assessed the effectiveness of killed OCV use after a cholera outbreak began. METHODOLOGY/PRINCIPAL FINDINGS: From 16 to 28 January 2008, vaccination campaigns with the Vietnamese killed OCV were held in two districts of Hanoi. No cholera cases were detected from 5 February to 4 March 2008, after which cases were again identified. Beginning 8 April 2008, residents of four districts of Hanoi admitted to one of five hospitals for acute diarrhea with onset after 5 March 2008 were recruited for a matched, hospital-based, case-control outbreak investigation. Cases were matched by hospital, admission date, district, gender, and age to controls admitted for non-diarrheal conditions. Subjects from the two vaccinated districts were evaluated to determine vaccine effectiveness. 54 case-control pairs from the vaccinated districts were included in the analysis. There were 8 (15% and 16 (30% vaccine recipients among cases and controls, respectively. The vaccine was 76% protective against cholera in this setting (95% CI 5% to 94%, P = 0.042 after adjusting for intake of dog meat or raw vegetables and not drinking boiled or bottled water most of the time. CONCLUSIONS/SIGNIFICANCE: This is the first study to explore the effectiveness of the reactive use of killed OCVs during a cholera outbreak. Our findings suggest that killed OCVs may have a role in controlling cholera outbreaks.

  9. Feasibility and acceptability of oral cholera vaccine mass ...

    African Journals Online (AJOL)

    ... acceptable by the community to conduct a largescale mass OCV campaign in Malawi within five weeks. Of 320,000 OCV doses received, Malawi managed to administer at least 294,221 (91.9%) of the doses. OCV could therefore be considered to be introduced as additional measure in cholera hot spot areas in Malawi.

  10. A retrospective analysis of oral cholera vaccine use, disease severity and deaths during an outbreak in South Sudan.

    Science.gov (United States)

    Bekolo, Cavin Epie; van Loenhout, Joris Adriaan Frank; Rodriguez-Llanes, Jose Manuel; Rumunu, John; Ramadan, Otim Patrick; Guha-Sapir, Debarati

    2016-09-01

    To determine whether pre-emptive oral cholera vaccination reduces disease severity and mortality in people who develop cholera disease during an outbreak. The study involved a retrospective analysis of demographic and clinical data from 41 cholera treatment facilities in South Sudan on patients who developed cholera disease between 23 April and 20 July 2014 during a large outbreak, a few months after a pre-emptive oral vaccination campaign. Patients who developed severe dehydration were regarded as having a severe cholera infection. Vaccinated and unvaccinated patients were compared and multivariate logistic regression analysis was used to identify factors associated with developing severe disease or death. In total, 4115 cholera patients were treated at the 41 facilities: 1946 (47.3%) had severe disease and 62 (1.5%) deaths occurred. Multivariate analysis showed that patients who received two doses of oral cholera vaccine were 4.5-fold less likely to develop severe disease than unvaccinated patients (adjusted odds ratio, aOR: 0.22; 95% confidence interval, CI: 0.11-0.44). Moreover, those with severe cholera were significantly more likely to die than those without (aOR: 4.76; 95% CI: 2.33-9.77). Pre-emptive vaccination with two doses of oral cholera vaccine was associated with a significant reduction in the likelihood of developing severe cholera disease during an outbreak in South Sudan. Moreover, severe disease was the strongest predictor of death. Two doses of oral cholera vaccine should be used in emergencies to reduce the disease burden.

  11. Knowledge of, attitudes toward, and preventive practices relating to cholera and oral cholera vaccine among urban high-risk groups: findings of a cross-sectional study in Dhaka, Bangladesh

    OpenAIRE

    Wahed, Tasnuva; Kaukab, Sheikh Shah Tanvir; Saha, Nirod Chandra; Khan, Iqbal Ansary; Khanam, Farhana; Chowdhury, Fahima; Saha, Amit; Khan, Ashraful Islam; Siddik, Ashraf Uddin; Cravioto, Alejandro; Qadri, Firdausi; Uddin, Jasim

    2013-01-01

    Background In endemic countries such as Bangladesh, consequences of cholera place an enormous financial and social burden on patients and their families. Cholera vaccines not only provide health benefits to susceptible populations but also have effects on the earning capabilities and financial stability of the family. Community-based research and evaluations are necessary to understand perceptions about and practices of the community relating to cholera and oral cholera vaccines. This may hel...

  12. Socio-cultural determinants of anticipated acceptance of an oral cholera vaccine in Western Kenya

    OpenAIRE

    SUNDARAM, N.; SCHAETTI, C.; CHAIGNAT, C.-L.; HUTUBESSY, R.; NYAMBEDHA, E. O.; MBONGA, L. A.; WEISS, M. G.

    2012-01-01

    SUMMARY Determinants of anticipated acceptance of an oral cholera vaccine (OCV) were studied in urban and rural communities of Western Kenya. An explanatory model interview administered to 379 community residents assessed anticipated vaccine acceptance at various prices from no cost to full-cost recovery, socio-cultural features of cholera and social characteristics. Nearly all (99%) residents indicated willingness to accept a no-cost OCV, 95% at a price of US$ 0?8, 73% at US$ 4?2 and 59% at ...

  13. Evaluation of Knowledge and Practices Regarding Cholera, Water Treatment, Hygiene, and Sanitation Before and After an Oral Cholera Vaccination Campaign-Haiti, 2013-2014.

    Science.gov (United States)

    Childs, Lana; François, Jeannot; Choudhury, Alina; Wannemuehler, Kathleen; Dismer, Amber; Hyde, Terri B; Yen, Catherine Y; Date, Kashmira A; Juin, Stanley; Katz, Mark A; Kantor, Erica Felker; Routh, Janell; Etheart, Melissa; Wright, Tracie; Adrien, Paul; Tohme, Rania A

    2016-12-07

    In 2013, the Government of Haiti implemented its first oral cholera vaccine (OCV) campaign in Petite Anse, an urban setting, and Cerca Carvajal, a rural commune. We conducted and compared responses to two independent cross-sectional knowledge and practices household surveys pre- (N = 297) and post- (N = 302) OCV campaign in Petite Anse. No significant differences in knowledge about causes, symptoms, and prevention of cholera were noted. Compared with precampaign respondents, fewer postcampaign respondents reported treating (66% versus 27%, P treatment practices necessary for cholera and other diarrheal diseases prevention were noted in the postcampaign survey. Future OCV campaigns in Haiti should be used as an opportunity to emphasize the importance of maintaining good water, sanitation, and hygiene practices, and include a comprehensive, integrated approach for cholera control. © The American Society of Tropical Medicine and Hygiene.

  14. Evaluation of Knowledge and Practices Regarding Cholera, Water Treatment, Hygiene, and Sanitation before and after an Oral Cholera Vaccination Campaign—Haiti, 2013–2014

    Science.gov (United States)

    Childs, Lana; François, Jeannot; Choudhury, Alina; Wannemuehler, Kathleen; Dismer, Amber; Hyde, Terri B.; Yen, Catherine Y.; Date, Kashmira A.; Juin, Stanley; Katz, Mark A.; Kantor, Erica Felker; Routh, Janell; Etheart, Melissa; Wright, Tracie; Adrien, Paul; Tohme, Rania A.

    2016-01-01

    In 2013, the Government of Haiti implemented its first oral cholera vaccine (OCV) campaign in Petite Anse, an urban setting, and Cerca Carvajal, a rural commune. We conducted and compared responses to two independent cross-sectional knowledge and practices household surveys pre- (N = 297) and post- (N = 302) OCV campaign in Petite Anse. No significant differences in knowledge about causes, symptoms, and prevention of cholera were noted. Compared with precampaign respondents, fewer postcampaign respondents reported treating (66% versus 27%, P treatment practices necessary for cholera and other diarrheal diseases prevention were noted in the postcampaign survey. Future OCV campaigns in Haiti should be used as an opportunity to emphasize the importance of maintaining good water, sanitation, and hygiene practices, and include a comprehensive, integrated approach for cholera control. PMID:27799642

  15. Safety of the recombinant cholera toxin B subunit, killed whole-cell (rBS-WC oral cholera vaccine in pregnancy.

    Directory of Open Access Journals (Sweden)

    Ramadhan Hashim

    Full Text Available Mass vaccinations are a main strategy in the deployment of oral cholera vaccines. Campaigns avoid giving vaccine to pregnant women because of the absence of safety data of the killed whole-cell oral cholera (rBS-WC vaccine. Balancing this concern is the known higher risk of cholera and of complications of pregnancy should cholera occur in these women, as well as the lack of expected adverse events from a killed oral bacterial vaccine.From January to February 2009, a mass rBS-WC vaccination campaign of persons over two years of age was conducted in an urban and a rural area (population 51,151 in Zanzibar. Pregnant women were advised not to participate in the campaign. More than nine months after the last dose of the vaccine was administered, we visited all women between 15 and 50 years of age living in the study area. The outcome of pregnancies that were inadvertently exposed to at least one oral cholera vaccine dose and those that were not exposed was evaluated. 13,736 (94% of the target women in the study site were interviewed. 1,151 (79% of the 1,453 deliveries in 2009 occurred during the period when foetal exposure to the vaccine could have occurred. 955 (83% out of these 1,151 mothers had not been vaccinated; the remaining 196 (17% mothers had received at least one dose of the oral cholera vaccine. There were no statistically significant differences in the odds ratios for birth outcomes among the exposed and unexposed pregnancies.We found no statistically significant evidence of a harmful effect of gestational exposure to the rBS-WC vaccine. These findings, along with the absence of a rational basis for expecting a risk from this killed oral bacterial vaccine, are reassuring but the study had insufficient power to detect infrequent events.ClinicalTrials.gov NCT00709410.

  16. An Estimation of Private Household Costs to Receive Free Oral Cholera Vaccine in Odisha, India

    Science.gov (United States)

    Mogasale, Vittal; Kar, Shantanu K.; Kim, Jong-Hoon; Mogasale, Vijayalaxmi V.; Kerketta, Anna S.; Patnaik, Bikash; Rath, Shyam Bandhu; Puri, Mahesh K.; You, Young Ae; Khuntia, Hemant K.; Maskery, Brian; Wierzba, Thomas F.; Sah, Binod

    2015-01-01

    Background Service provider costs for vaccine delivery have been well documented; however, vaccine recipients’ costs have drawn less attention. This research explores the private household out-of-pocket and opportunity costs incurred to receive free oral cholera vaccine during a mass vaccination campaign in rural Odisha, India. Methods Following a government-driven oral cholera mass vaccination campaign targeting population over one year of age, a questionnaire-based cross-sectional survey was conducted to estimate private household costs among vaccine recipients. The questionnaire captured travel costs as well as time and wage loss for self and accompanying persons. The productivity loss was estimated using three methods: self-reported, government defined minimum daily wages and gross domestic product per capita in Odisha. Findings On average, families were located 282.7 (SD = 254.5) meters from the nearest vaccination booths. Most family members either walked or bicycled to the vaccination sites and spent on average 26.5 minutes on travel and 15.7 minutes on waiting. Depending upon the methodology, the estimated productivity loss due to potential foregone income ranged from $0.15 to $0.29 per dose of cholera vaccine received. The private household cost of receiving oral cholera vaccine constituted 24.6% to 38.0% of overall vaccine delivery costs. Interpretation The private household costs resulting from productivity loss for receiving a free oral cholera vaccine is a substantial proportion of overall vaccine delivery cost and may influence vaccine uptake. Policy makers and program managers need to recognize the importance of private costs and consider how to balance programmatic delivery costs with private household costs to receive vaccines. PMID:26352143

  17. An Estimation of Private Household Costs to Receive Free Oral Cholera Vaccine in Odisha, India.

    Directory of Open Access Journals (Sweden)

    Vittal Mogasale

    Full Text Available Service provider costs for vaccine delivery have been well documented; however, vaccine recipients' costs have drawn less attention. This research explores the private household out-of-pocket and opportunity costs incurred to receive free oral cholera vaccine during a mass vaccination campaign in rural Odisha, India.Following a government-driven oral cholera mass vaccination campaign targeting population over one year of age, a questionnaire-based cross-sectional survey was conducted to estimate private household costs among vaccine recipients. The questionnaire captured travel costs as well as time and wage loss for self and accompanying persons. The productivity loss was estimated using three methods: self-reported, government defined minimum daily wages and gross domestic product per capita in Odisha.On average, families were located 282.7 (SD = 254.5 meters from the nearest vaccination booths. Most family members either walked or bicycled to the vaccination sites and spent on average 26.5 minutes on travel and 15.7 minutes on waiting. Depending upon the methodology, the estimated productivity loss due to potential foregone income ranged from $0.15 to $0.29 per dose of cholera vaccine received. The private household cost of receiving oral cholera vaccine constituted 24.6% to 38.0% of overall vaccine delivery costs.The private household costs resulting from productivity loss for receiving a free oral cholera vaccine is a substantial proportion of overall vaccine delivery cost and may influence vaccine uptake. Policy makers and program managers need to recognize the importance of private costs and consider how to balance programmatic delivery costs with private household costs to receive vaccines.

  18. Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands

    OpenAIRE

    Burnett, Eleanor; Dalipanda, Tenneth; Ogaoga, Divi; Gaiofa, Jenny; Jilini, Gregory; Halpin, Alison; Dietz, Vance; Date, Kashmira; Mintz, Eric; Hyde, Terri; Wannemuehler, Kathleen; Yen, Catherine

    2016-01-01

    Background In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1?15 years in selected communities in Choiseul and Western Provinces. Methodology and Principal Findings We conducted a post-vaccination campaign, household-level survey about knowledg...

  19. Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands.

    Science.gov (United States)

    Burnett, Eleanor; Dalipanda, Tenneth; Ogaoga, Divi; Gaiofa, Jenny; Jilini, Gregory; Halpin, Alison; Dietz, Vance; Date, Kashmira; Mintz, Eric; Hyde, Terri; Wannemuehler, Kathleen; Yen, Catherine

    2016-08-01

    In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1-15 years in selected communities in Choiseul and Western Provinces. We conducted a post-vaccination campaign, household-level survey about knowledge, attitudes, and practices regarding diarrhea and cholera in areas targeted and not targeted for cholera vaccination. Respondents in vaccinated areas were more likely to have received cholera education in the previous 6 months (33% v. 9%; p = 0.04), to know signs and symptoms (64% vs. 22%; p = 0.02) and treatment (96% vs. 50%; p = 0.02) of cholera, and to be aware of cholera vaccine (48% vs. 14%; p = 0.02). There were no differences in water, sanitation, and hygiene practices. This pre-emptive OCV campaign in a cholera-naïve community provided a unique opportunity to assess household-level knowledge, attitudes, and practices regarding diarrhea, cholera, and water, sanitation, and hygiene (WASH). Our findings suggest that education provided during the vaccination campaign may have reinforced earlier mass messaging about cholera and diarrheal disease in vaccinated communities.

  20. Knowledge, Attitudes, and Practices regarding Diarrhea and Cholera following an Oral Cholera Vaccination Campaign in the Solomon Islands.

    Directory of Open Access Journals (Sweden)

    Eleanor Burnett

    2016-08-01

    Full Text Available In response to a 2011 cholera outbreak in Papua New Guinea, the Government of the Solomon Islands initiated a cholera prevention program which included cholera disease prevention and treatment messaging, community meetings, and a pre-emptive cholera vaccination campaign targeting 11,000 children aged 1-15 years in selected communities in Choiseul and Western Provinces.We conducted a post-vaccination campaign, household-level survey about knowledge, attitudes, and practices regarding diarrhea and cholera in areas targeted and not targeted for cholera vaccination. Respondents in vaccinated areas were more likely to have received cholera education in the previous 6 months (33% v. 9%; p = 0.04, to know signs and symptoms (64% vs. 22%; p = 0.02 and treatment (96% vs. 50%; p = 0.02 of cholera, and to be aware of cholera vaccine (48% vs. 14%; p = 0.02. There were no differences in water, sanitation, and hygiene practices.This pre-emptive OCV campaign in a cholera-naïve community provided a unique opportunity to assess household-level knowledge, attitudes, and practices regarding diarrhea, cholera, and water, sanitation, and hygiene (WASH. Our findings suggest that education provided during the vaccination campaign may have reinforced earlier mass messaging about cholera and diarrheal disease in vaccinated communities.

  1. Effectiveness of one dose of oral cholera vaccine in response to an outbreak: a case-cohort study.

    Science.gov (United States)

    Azman, Andrew S; Parker, Lucy A; Rumunu, John; Tadesse, Fisseha; Grandesso, Francesco; Deng, Lul L; Lino, Richard Laku; Bior, Bior K; Lasuba, Michael; Page, Anne-Laure; Ontweka, Lameck; Llosa, Augusto E; Cohuet, Sandra; Pezzoli, Lorenzo; Sodjinou, Dossou Vincent; Abubakar, Abdinasir; Debes, Amanda K; Mpairwe, Allan M; Wamala, Joseph F; Jamet, Christine; Lessler, Justin; Sack, David A; Quilici, Marie-Laure; Ciglenecki, Iza; Luquero, Francisco J

    2016-11-01

    Oral cholera vaccines represent a new effective tool to fight cholera and are licensed as two-dose regimens with 2-4 weeks between doses. Evidence from previous studies suggests that a single dose of oral cholera vaccine might provide substantial direct protection against cholera. During a cholera outbreak in May, 2015, in Juba, South Sudan, the Ministry of Health, Médecins Sans Frontières, and partners engaged in the first field deployment of a single dose of oral cholera vaccine to enhance the outbreak response. We did a vaccine effectiveness study in conjunction with this large public health intervention. We did a case-cohort study, combining information on the vaccination status and disease outcomes from a random cohort recruited from throughout the city of Juba with that from all the cases detected. Eligible cases were those aged 1 year or older on the first day of the vaccination campaign who sought care for diarrhoea at all three cholera treatment centres and seven rehydration posts throughout Juba. Confirmed cases were suspected cases who tested positive to PCR for Vibrio cholerae O1. We estimated the short-term protection (direct and indirect) conferred by one dose of cholera vaccine (Shanchol, Shantha Biotechnics, Hyderabad, India). Between Aug 9, 2015, and Sept 29, 2015, we enrolled 87 individuals with suspected cholera, and an 898-person cohort from throughout Juba. Of the 87 individuals with suspected cholera, 34 were classified as cholera positive, 52 as cholera negative, and one had indeterminate results. Of the 858 cohort members who completed a follow-up visit, none developed clinical cholera during follow-up. The unadjusted single-dose vaccine effectiveness was 80·2% (95% CI 61·5-100·0) and after adjusting for potential confounders was 87·3% (70·2-100·0). One dose of Shanchol was effective in preventing medically attended cholera in this study. These results support the use of a single-dose strategy in outbreaks in similar epidemiological

  2. Oral administration of a recombinant cholera toxin B subunit promotes mucosal healing in the colon.

    Science.gov (United States)

    Baldauf, K J; Royal, J M; Kouokam, J C; Haribabu, B; Jala, V R; Yaddanapudi, K; Hamorsky, K T; Dryden, G W; Matoba, N

    2017-07-01

    Cholera toxin B subunit (CTB) is a component of a licensed oral cholera vaccine. However, CTB has pleiotropic immunomodulatory effects whose impacts on the gut are not fully understood. Here, we found that oral administration in mice of a plant-made recombinant CTB (CTBp) significantly increased several immune cell populations in the colon lamina propria. Global gene expression analysis revealed that CTBp had more pronounced impacts on the colon than the small intestine, with significant activation of TGFβ-mediated pathways in the colon epithelium. The clinical relevance of CTBp-induced impacts on colonic mucosa was examined. In a human colon epithelial model using Caco2 cells, CTBp, but not the non-GM1-binding mutant G33D-CTBp, induced TGFβ-mediated wound healing. In a dextran sodium sulfate (DSS) acute colitis mouse model, oral administration of CTBp protected against colon mucosal damage as manifested by mitigated body weight loss, decreased histopathological scores, and blunted escalation of inflammatory cytokine levels while inducing wound healing-related genes. Furthermore, biweekly oral administration of CTBp significantly reduced disease severity and tumorigenesis in the azoxymethane/DSS model of ulcerative colitis and colon cancer. Altogether, these results demonstrate CTBp's ability to enhance mucosal healing in the colon, highlighting its potential application in ulcerative colitis therapy besides cholera vaccination.

  3. Socio-cultural determinants of anticipated acceptance of an oral cholera vaccine in Western Kenya.

    Science.gov (United States)

    Sundaram, N; Schaetti, C; Chaignat, C-L; Hutubessy, R; Nyambedha, E O; Mbonga, L A; Weiss, M G

    2013-03-01

    Determinants of anticipated acceptance of an oral cholera vaccine (OCV) were studied in urban and rural communities of Western Kenya. An explanatory model interview administered to 379 community residents assessed anticipated vaccine acceptance at various prices from no cost to full-cost recovery, socio-cultural features of cholera and social characteristics. Nearly all (99%) residents indicated willingness to accept a no-cost OCV, 95% at a price of US$ 0·8, 73% at US$ 4·2 and 59% at US$ 8·4. Logistic regression models analysed socio-cultural determinants of anticipated OCV acceptance. Prominence of non-specific symptoms for cholera was negatively associated with acceptance. A cholera-specific symptom (thirst), self-help referring to prayer, income and education were positively associated. In the high-cost model, education was no longer significant and reliance on herbal treatment was a significant determinant of vaccine non-acceptance. Findings suggest high motivation for OCVs, if affordable. Socio-cultural determinants are better predictors of anticipated acceptance than socio-demographic factors alone.

  4. Immunogenicity of a killed bivalent (O1 and O139 whole cell oral cholera vaccine, Shanchol, in Haiti.

    Directory of Open Access Journals (Sweden)

    Richelle C Charles

    2014-05-01

    Full Text Available Studies of the immunogenicity of the killed bivalent whole cell oral cholera vaccine, Shanchol, have been performed in historically cholera-endemic areas of Asia. There is a need to assess the immunogenicity of the vaccine in Haiti and other populations without historical exposure to Vibrio cholerae.We measured immune responses after administration of Shanchol, in 25 adults, 51 older children (6-17 years, and 47 younger children (1-5 years in Haiti, where cholera was introduced in 2010. A≥4-fold increase in vibriocidal antibody titer against V. cholerae O1 Ogawa was observed in 91% of adults, 74% of older children, and 73% of younger children after two doses of Shanchol; similar responses were observed against the Inaba serotype. A≥2-fold increase in serum O-antigen specific polysaccharide IgA antibody levels against V. cholerae O1 Ogawa was observed in 59% of adults, 45% of older children, and 61% of younger children; similar responses were observed against the Inaba serotype. We compared immune responses in Haitian individuals with age- and blood group-matched individuals from Bangladesh, a historically cholera-endemic area. The geometric mean vibriocidal titers after the first dose of vaccine were lower in Haitian than in Bangladeshi vaccinees. However, the mean vibriocidal titers did not differ between the two groups after the second dose of the vaccine.A killed bivalent whole cell oral cholera vaccine, Shanchol, is highly immunogenic in Haitian adults and children. A two-dose regimen may be important in Haiti, and other populations lacking previous repeated exposures to V. cholerae.

  5. Single-dose Live Oral Cholera Vaccine CVD 103-HgR Protects Against Human Experimental Infection With Vibrio cholerae O1 El Tor.

    Science.gov (United States)

    Chen, Wilbur H; Cohen, Mitchell B; Kirkpatrick, Beth D; Brady, Rebecca C; Galloway, David; Gurwith, Marc; Hall, Robert H; Kessler, Robert A; Lock, Michael; Haney, Douglas; Lyon, Caroline E; Pasetti, Marcela F; Simon, Jakub K; Szabo, Flora; Tennant, Sharon; Levine, Myron M

    2016-06-01

    No licensed cholera vaccine is presently available in the United States. Cholera vaccines available in other countries require 2 spaced doses. A single-dose cholera vaccine that can rapidly protect short-notice travelers to high-risk areas and help control explosive outbreaks where logistics render 2-dose immunization regimens impractical would be a major advance.PXVX0200, based on live attenuated Vibrio cholerae O1 classical Inaba vaccine strain CVD 103-HgR, elicits seroconversion of vibriocidal antibodies (a correlate of protection) within 10 days of a single oral dose. We investigated the protection conferred by this vaccine in a human cholera challenge model. Consenting healthy adult volunteers, 18-45 years old, were randomly allocated 1:1 to receive 1 oral dose of vaccine (approximately 5 × 10(8) colony-forming units [CFU]) or placebo in double-blind fashion. Volunteers ingested approximately 1 × 10(5) CFU of wild-type V. cholerae O1 El Tor Inaba strain N16961 10 days or 3 months after vaccination and were observed on an inpatient research ward for stool output measurement and management of hydration. The vaccine was well tolerated, with no difference in adverse event frequency among 95 vaccinees vs 102 placebo recipients. The primary endpoint, moderate (≥3.0 L) to severe (≥5.0 L) diarrheal purge, occurred in 39 of 66 (59.1%) placebo controls but only 2 of 35 (5.7%) vaccinees at 10 days (vaccine efficacy, 90.3%; P < .0001) and 4 of 33 (12.1%) vaccinees at 3 months (vaccine efficacy, 79.5%; P < .0001). The significant vaccine efficacy documented 10 days and 3 months after 1 oral dose of PXVX0200 supports further development as a single-dose cholera vaccine. NCT01895855. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  6. Oral Cholera Vaccine Coverage during an Outbreak and Humanitarian Crisis, Iraq, 2015.

    Science.gov (United States)

    Lam, Eugene; Al-Tamimi, Wasan; Russell, Steven Paul; Butt, Muhammad Obaid-Ul Islam; Blanton, Curtis; Musani, Altaf Sadrudin; Date, Kashmira

    2017-01-01

    During November-December 2015, as part of the 2015 cholera outbreak response in Iraq, the Iraqi Ministry of Health targeted ≈255,000 displaced persons >1 year of age with 2 doses of oral cholera vaccine (OCV). All persons who received vaccines were living in selected refugee camps, internally displaced persons camps, and collective centers. We conducted a multistage cluster survey to obtain OCV coverage estimates in 10 governorates that were targeted during the campaign. In total, 1,226 household and 5,007 individual interviews were conducted. Overall, 2-dose OCV coverage in the targeted camps was 87% (95% CI 85%-89%). Two-dose OCV coverage in the 3 northern governorates (91%; 95% CI 87%-94%) was higher than that in the 7 southern and central governorates (80%; 95% CI 77%-82%). The experience in Iraq demonstrates that OCV campaigns can be successfully implemented as part of a comprehensive response to cholera outbreaks among high-risk populations in conflict settings.

  7. Comparison of immune responses to a killed bivalent whole cell oral cholera vaccine between endemic and less endemic settings.

    Science.gov (United States)

    Desai, Sachin N; Akalu, Zenebe; Teferi, Mekonnen; Manna, Byomkesh; Teshome, Samuel; Park, Ju Yeon; Yang, Jae Seung; Kim, Deok Ryun; Kanungo, Suman; Digilio, Laura

    2016-02-01

    Studies on safety, immunogenicity and efficacy of the killed, bivalent whole cell oral cholera vaccine (Shanchol) have been conducted in historically endemic settings of Asia. Recent cholera vaccination campaigns in Haiti and Guinea have also demonstrated favourable immunogenicity and effectiveness in nonendemic outbreak settings. We performed a secondary analysis, comparing immune responses of Shanchol from two randomised controlled trials performed in an endemic and a less endemic area (Addis Ababa) during a nonoutbreak setting. While Shanchol may offer some degree of immediate protection in primed populations living in cholera endemic areas, as well as being highly immunogenic in less endemic settings, understanding the characteristics of immune responses in each of these areas is vital in determining ideal dosing strategies that offer the greatest public health impact to populations from areas with varying degrees of cholera endemicity. © 2015 John Wiley & Sons Ltd.

  8. Alga-Produced Cholera Toxin-Pfs25 Fusion Proteins as Oral Vaccines

    Science.gov (United States)

    Gregory, James A.; Topol, Aaron B.; Doerner, David Z.

    2013-01-01

    Infectious diseases disproportionately affect indigent regions and are the greatest cause of childhood mortality in developing countries. Practical, low-cost vaccines for use in these countries are paramount to reducing disease burdens and concomitant poverty. Algae are a promising low-cost system for producing vaccines that can be orally delivered, thereby avoiding expensive purification and injectable delivery. We engineered the chloroplast of the eukaryotic alga Chlamydomonas reinhardtii to produce a chimeric protein consisting of the 25-kDa Plasmodium falciparum surface protein (Pfs25) fused to the β subunit of the cholera toxin (CtxB) to investigate an alga-based whole-cell oral vaccine. Pfs25 is a promising malaria transmission-blocking vaccine candidate that has been difficult to produce in traditional recombinant systems due to its structurally complex tandem repeats of epidermal growth factor-like domains. The noncatalytic CtxB domain of the cholera holotoxin assembles into a pentameric structure and acts as a mucosal adjuvant by binding GM1 ganglioside receptors on gut epithelial cells. We demonstrate that CtxB-Pfs25 accumulates as a soluble, properly folded and functional protein within algal chloroplasts, and it is stable in freeze-dried alga cells at ambient temperatures. In mice, oral vaccination using freeze-dried algae that produce CtxB-Pfs25 elicited CtxB-specific serum IgG antibodies and both CtxB- and Pfs25-specific secretory IgA antibodies. These data suggest that algae are a promising system for production and oral delivery of vaccine antigens, but as an orally delivered adjuvant, CtxB is best suited for eliciting secretory IgA antibodies for vaccine antigens against pathogens that invade mucosal surfaces using this strategy. PMID:23603678

  9. Improving Community Coverage of Oral Cholera Mass Vaccination Campaigns: Lessons Learned in Zanzibar

    Science.gov (United States)

    Schaetti, Christian; Ali, Said M.; Chaignat, Claire-Lise; Khatib, Ahmed M.; Hutubessy, Raymond; Weiss, Mitchell G.

    2012-01-01

    Background Recent research in two cholera-endemic communities of Zanzibar has shown that a majority (∼94%) of the adult population was willing to receive free oral cholera vaccines (OCVs). Since OCV uptake in the 2009 campaign reached only ∼50% in these communities, an evaluation of social and cultural factors and of barriers was conducted to understand this difference for future cholera control planning. Methodology/Principal Findings A random sample of 367 adult peri-urban and rural community residents (46.6% immunized vs. 53.4% unimmunized) was studied with a semi-structured interview that inquired about social and cultural features of cholera depicted in a vignette and barriers to OCV uptake. Symptoms (rectal pain, loose skin only in rural community) and perceived causes (uncovered food, contact with contaminated water) specific for severe diarrhea were associated with uptake. Purchasing drugs from pharmacies to stop diarrhea and vomiting was negatively associated with uptake. Increasing household size, age and previous enteric illness episode were positively related to uptake, the latter only at the rural site. The most prominent barrier to uptake was competing obligations or priorities (reported by 74.5%, identified as most important barrier by 49.5%). Next most prominent barriers were lacking information about the campaign (29.6%, 12.2%), sickness (14.3%, 13.3%) and fear of possible vaccine side effects (15.3%, 5.6%). The majority of unvaccinated respondents requested repetition of the vaccination with free OCVs. Conclusions/Significance Factors associated with uptake indicated a positive impact of the vaccination campaign and of sensitization activities on vaccine acceptance behavior. Unlike communities opposed to cholera control or settings where public confidence in vaccines is lacking, identified barriers to uptake indicated a good campaign implementation and trust in the health system. Despite prospects and demand for repeating the vaccination

  10. Social and cultural determinants of anticipated acceptance of an oral cholera vaccine prior to a mass vaccination campaign in Zanzibar.

    Science.gov (United States)

    Schaetti, Christian; Chaignat, Claire-Lise; Hutubessy, Raymond; Khatib, Ahmed M; Ali, Said M; Schindler, Christian; Weiss, Mitchell G

    2011-12-01

    Despite improvements in sanitation and water supply, cholera remains a serious public health burden. Vaccination is included among recommendations for cholera control. Cultural concepts of illness are likely to affect vaccine acceptance. This study examined social and cultural determinants of anticipated acceptance of an oral cholera vaccine (OCV) prior to a mass vaccination campaign in Zanzibar. Using a cultural epidemiological approach, 356 unaffected adult residents were studied with vignette-based semi-structured interviews. Anticipated acceptance was high for a free OCV (94%), but declined with increasing price. Logistic regression models examined social and cultural determinants of anticipated acceptance at low (USD 0.9), medium (USD 4.5) and high (USD 9) price. Models including somatic symptoms (low and high price), social impact (low and medium) and perceived causes (medium and high) explained anticipated OCV acceptance better than models containing only socio-demographic characteristics. Identifying thirst with cholera was positively associated with anticipated acceptance of the low-priced OCV, but acknowledging the value of home-based rehydration was negatively associated. Concern about spreading the infection to others was positively associated at low price among rural respondents. Confidence in the health system response to cholera outbreaks was negatively associated at medium price among peri-urban respondents. Identifying witchcraft as cause of cholera was negatively associated at medium and high price. Anticipated acceptance of free OCVs is nearly universal in cholera-endemic areas of Zanzibar; pre-intervention assessments of community demand for OCV should not only consider the social epidemiology, but also examine local socio-cultural features of cholera-like illness that explain vaccine acceptance.

  11. Cost Evaluation of a Government-Conducted Oral Cholera Vaccination Campaign-Haiti, 2013.

    Science.gov (United States)

    Routh, Janell A; Sreenivasan, Nandini; Adhikari, Bishwa B; Andrecy, Lesly L; Bernateau, Margarette; Abimbola, Taiwo; Njau, Joseph; Jackson, Ernsley; Juin, Stanley; Francois, Jeannot; Tohme, Rania A; Meltzer, Martin I; Katz, Mark A; Mintz, Eric D

    2017-10-01

    The devastating 2010 cholera epidemic in Haiti prompted the government to introduce oral cholera vaccine (OCV) in two high-risk areas of Haiti. We evaluated the direct costs associated with the government's first vaccine campaign implemented in August-September 2013. We analyzed data for major cost categories and assessed the efficiency of available campaign resources to vaccinate the target population. For a target population of 107,906 persons, campaign costs totaled $624,000 and 215,295 OCV doses were dispensed. The total vaccine and operational cost was $2.90 per dose; vaccine alone cost $1.85 per dose, vaccine delivery and administration $0.70 per dose, and vaccine storage and transport $0.35 per dose. Resources were greater than needed-our analyses suggested that approximately 2.5-6 times as many persons could have been vaccinated during this campaign without increasing the resources allocated for vaccine delivery and administration. These results can inform future OCV campaigns in Haiti.

  12. Optimal allocation of the limited oral cholera vaccine supply between endemic and epidemic settings.

    Science.gov (United States)

    Moore, Sean M; Lessler, Justin

    2015-10-06

    The World Health Organization (WHO) recently established a global stockpile of oral cholera vaccine (OCV) to be preferentially used in epidemic response (reactive campaigns) with any vaccine remaining after 1 year allocated to endemic settings. Hence, the number of cholera cases or deaths prevented in an endemic setting represents the minimum utility of these doses, and the optimal risk-averse response to any reactive vaccination request (i.e. the minimax strategy) is one that allocates the remaining doses between the requested epidemic response and endemic use in order to ensure that at least this minimum utility is achieved. Using mathematical models, we find that the best minimax strategy is to allocate the majority of doses to reactive campaigns, unless the request came late in the targeted epidemic. As vaccine supplies dwindle, the case for reactive use of the remaining doses grows stronger. Our analysis provides a lower bound for the amount of OCV to keep in reserve when responding to any request. These results provide a strategic context for the fulfilment of requests to the stockpile, and define allocation strategies that minimize the number of OCV doses that are allocated to suboptimal situations. © 2015 The Authors.

  13. Comparison of two control groups for estimation of oral cholera vaccine effectiveness using a case-control study design.

    Science.gov (United States)

    Franke, Molly F; Jerome, J Gregory; Matias, Wilfredo R; Ternier, Ralph; Hilaire, Isabelle J; Harris, Jason B; Ivers, Louise C

    2017-10-13

    Case-control studies to quantify oral cholera vaccine effectiveness (VE) often rely on neighbors without diarrhea as community controls. Test-negative controls can be easily recruited and may minimize bias due to differential health-seeking behavior and recall. We compared VE estimates derived from community and test-negative controls and conducted bias-indicator analyses to assess potential bias with community controls. From October 2012 through November 2016, patients with acute watery diarrhea were recruited from cholera treatment centers in rural Haiti. Cholera cases had a positive stool culture. Non-cholera diarrhea cases (test-negative controls and non-cholera diarrhea cases for bias-indicator analyses) had a negative culture and rapid test. Up to four community controls were matched to diarrhea cases by age group, time, and neighborhood. Primary analyses included 181 cholera cases, 157 non-cholera diarrhea cases, 716 VE community controls and 625 bias-indicator community controls. VE for self-reported vaccination with two doses was consistent across the two control groups, with statistically significant VE estimates ranging from 72 to 74%. Sensitivity analyses revealed similar, though somewhat attenuated estimates for self-reported two dose VE. Bias-indicator estimates were consistently less than one, with VE estimates ranging from 19 to 43%, some of which were statistically significant. OCV estimates from case-control analyses using community and test-negative controls were similar. While bias-indicator analyses suggested possible over-estimation of VE estimates using community controls, test-negative analyses suggested this bias, if present, was minimal. Test-negative controls can be a valid low-cost and time-efficient alternative to community controls for OCV effectiveness estimation and may be especially relevant in emergency situations. Copyright © 2017. Published by Elsevier Ltd.

  14. Pregnancy Outcomes after a Mass Vaccination Campaign with an Oral Cholera Vaccine in Guinea: A Retrospective Cohort Study.

    Directory of Open Access Journals (Sweden)

    Lise Grout

    2015-12-01

    Full Text Available Since 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2-36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC, included all people living in the targeted areas aged ≥ 1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women.From 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7-4.8 for fetuses exposed to BivWC vaccine and 2.6% (0.7-4.5 for non-exposed fetuses. The incidence of malformation was 0.6% (0.1-1.0 and 1.2% (0.0-2.5 in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5-2.25], p = 0.818 or malformations (aRR = 0.50 [95%CI: 0.13-1.91], p = 0.314.In this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a

  15. Glucose- but not rice-based oral rehydration therapy enhances the production of virulence determinants in the human pathogen Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Juliane Kühn

    2014-12-01

    Full Text Available Despite major attempts to prevent cholera transmission, millions of people worldwide still must address this devastating disease. Cholera research has so far mainly focused on the causative agent, the bacterium Vibrio cholerae, or on disease treatment, but rarely were results from both fields interconnected. Indeed, the treatment of this severe diarrheal disease is mostly accomplished by oral rehydration therapy (ORT, whereby water and electrolytes are replenished. Commonly distributed oral rehydration salts also contain glucose. Here, we analyzed the effects of glucose and alternative carbon sources on the production of virulence determinants in the causative agent of cholera, the bacterium Vibrio cholerae during in vitro experimentation. We demonstrate that virulence gene expression and the production of cholera toxin are enhanced in the presence of glucose or similarly transported sugars in a ToxR-, TcpP- and ToxT-dependent manner. The virulence genes were significantly less expressed if alternative non-PTS carbon sources, including rice-based starch, were utilized. Notably, even though glucose-based ORT is commonly used, field studies indicated that rice-based ORT performs better. We therefore used a spatially explicit epidemiological model to demonstrate that the better performing rice-based ORT could have a significant impact on epidemic progression based on the recent outbreak of cholera in Haiti. Our results strongly support a change of carbon source for the treatment of cholera, especially in epidemic settings.

  16. Oral Cholera Vaccination Delivery Cost in Low- and Middle-Income Countries: An Analysis Based on Systematic Review.

    Science.gov (United States)

    Mogasale, Vittal; Ramani, Enusa; Wee, Hyeseung; Kim, Jerome H

    2016-12-01

    Use of the oral cholera vaccine (OCV) is a vital short-term strategy to control cholera in endemic areas with poor water and sanitation infrastructure. Identifying, estimating, and categorizing the delivery costs of OCV campaigns are useful in analyzing cost-effectiveness, understanding vaccine affordability, and in planning and decision making by program managers and policy makers. To review and re-estimate oral cholera vaccination program costs and propose a new standardized categorization that can help in collation, analysis, and comparison of delivery costs across countries. Peer reviewed publications listed in PubMed database, Google Scholar and World Health Organization (WHO) websites and unpublished data from organizations involved in oral cholera vaccination. The publications and reports containing oral cholera vaccination delivery costs, conducted in low- and middle-income countries based on World Bank Classification. Limits are humans and publication date before December 31st, 2014. No participants are involved, only costs are collected. Oral cholera vaccination and cost estimation. A systematic review was conducted using pre-defined inclusion and exclusion criteria. Cost items were categorized into four main cost groups: vaccination program preparation, vaccine administration, adverse events following immunization and vaccine procurement; the first three groups constituting the vaccine delivery costs. The costs were re-estimated in 2014 US dollars (US$) and in international dollar (I$). Ten studies were identified and included in the analysis. The vaccine delivery costs ranged from US$0.36 to US$ 6.32 (in US$2014) which was equivalent to I$ 0.99 to I$ 16.81 (in I$2014). The vaccine procurement costs ranged from US$ 0.29 to US$ 29.70 (in US$2014), which was equivalent to I$ 0.72 to I$ 78.96 (in I$2014). The delivery costs in routine immunization systems were lowest from US$ 0.36 (in US$2014) equivalent to I$ 0.99 (in I$2014). The reported cost categories

  17. Oral Cholera Vaccination Delivery Cost in Low- and Middle-Income Countries: An Analysis Based on Systematic Review

    Science.gov (United States)

    Ramani, Enusa; Wee, Hyeseung; Kim, Jerome H.

    2016-01-01

    Background Use of the oral cholera vaccine (OCV) is a vital short-term strategy to control cholera in endemic areas with poor water and sanitation infrastructure. Identifying, estimating, and categorizing the delivery costs of OCV campaigns are useful in analyzing cost-effectiveness, understanding vaccine affordability, and in planning and decision making by program managers and policy makers. Objectives To review and re-estimate oral cholera vaccination program costs and propose a new standardized categorization that can help in collation, analysis, and comparison of delivery costs across countries. Data sources Peer reviewed publications listed in PubMed database, Google Scholar and World Health Organization (WHO) websites and unpublished data from organizations involved in oral cholera vaccination. Study eligibility criteria The publications and reports containing oral cholera vaccination delivery costs, conducted in low- and middle-income countries based on World Bank Classification. Limits are humans and publication date before December 31st, 2014. Participants No participants are involved, only costs are collected. Intervention Oral cholera vaccination and cost estimation. Study appraisal and synthesis method A systematic review was conducted using pre-defined inclusion and exclusion criteria. Cost items were categorized into four main cost groups: vaccination program preparation, vaccine administration, adverse events following immunization and vaccine procurement; the first three groups constituting the vaccine delivery costs. The costs were re-estimated in 2014 US dollars (US$) and in international dollar (I$). Results Ten studies were identified and included in the analysis. The vaccine delivery costs ranged from US$0.36 to US$ 6.32 (in US$2014) which was equivalent to I$ 0.99 to I$ 16.81 (in I$2014). The vaccine procurement costs ranged from US$ 0.29 to US$ 29.70 (in US$2014), which was equivalent to I$ 0.72 to I$ 78.96 (in I$2014). The delivery costs in

  18. Mechanisms Underlying the Immune Response Generated by an Oral Vibrio cholerae Vaccine

    Directory of Open Access Journals (Sweden)

    Danylo Sirskyj

    2016-07-01

    Full Text Available Mechanistic details underlying the resulting protective immune response generated by mucosal vaccines remain largely unknown. We investigated the involvement of Toll-like receptor signaling in the induction of humoral immune responses following oral immunization with Dukoral, comparing wild type mice with TLR-2-, TLR-4-, MyD88- and Trif-deficient mice. Although all groups generated similar levels of IgG antibodies, the proliferation of CD4+ T-cells in response to V. cholerae was shown to be mediated via MyD88/TLR signaling, and independently of Trif signaling. The results demonstrate differential requirements for generation of immune responses. These results also suggest that TLR pathways may be modulators of the quality of immune response elicited by the Dukoral vaccine. Determining the critical signaling pathways involved in the induction of immune response to this vaccine would be beneficial, and could contribute to more precisely-designed versions of other oral vaccines in the future.

  19. Sociocultural determinants of anticipated oral cholera vaccine acceptance in three African settings: a meta-analytic approach.

    Science.gov (United States)

    Sundaram, Neisha; Schaetti, Christian; Merten, Sonja; Schindler, Christian; Ali, Said M; Nyambedha, Erick O; Lapika, Bruno; Chaignat, Claire-Lise; Hutubessy, Raymond; Weiss, Mitchell G

    2016-01-14

    Controlling cholera remains a significant challenge in Sub-Saharan Africa. In areas where access to safe water and sanitation are limited, oral cholera vaccine (OCV) can save lives. Establishment of a global stockpile for OCV reflects increasing priority for use of cholera vaccines in endemic settings. Community acceptance of vaccines, however, is critical and sociocultural features of acceptance require attention for effective implementation. This study identifies and compares sociocultural determinants of anticipated OCV acceptance across populations in Southeastern Democratic Republic of Congo, Western Kenya and Zanzibar. Cross-sectional studies were conducted using similar but locally-adapted semistructured interviews among 1095 respondents in three African settings. Logistic regression models identified sociocultural determinants of OCV acceptance from these studies in endemic areas of Southeastern Democratic Republic of Congo (SE-DRC), Western Kenya (W-Kenya) and Zanzibar. Meta-analytic techniques highlighted common and distinctive determinants in the three settings. Anticipated OCV acceptance was high in all settings. More than 93% of community respondents overall indicated interest in a no-cost vaccine. Higher anticipated acceptance was observed in areas with less access to public health facilities. In all settings awareness of cholera prevention methods (safe food consumption and garbage disposal) and relating ingestion to cholera causation were associated with greater acceptance. Higher age, larger households, lack of education, social vulnerability and knowledge of oral rehydration solution for self-treatment were negatively associated with anticipated OCV acceptance. Setting-specific determinants of acceptance included reporting a reliable income (W-Kenya and Zanzibar, not SE-DRC). In SE-DRC, intention to purchase an OCV appeared unrelated to ability to pay. Rural residents were less likely than urban counterparts to accept an OCV in W-Kenya, but more

  20. Costs of Illness Due to Cholera, Costs of Immunization and Cost-Effectiveness of an Oral Cholera Mass Vaccination Campaign in Zanzibar

    Science.gov (United States)

    Schaetti, Christian; Weiss, Mitchell G.; Ali, Said M.; Chaignat, Claire-Lise; Khatib, Ahmed M.; Reyburn, Rita; Duintjer Tebbens, Radboud J.; Hutubessy, Raymond

    2012-01-01

    Background The World Health Organization (WHO) recommends oral cholera vaccines (OCVs) as a supplementary tool to conventional prevention of cholera. Dukoral, a killed whole-cell two-dose OCV, was used in a mass vaccination campaign in 2009 in Zanzibar. Public and private costs of illness (COI) due to endemic cholera and costs of the mass vaccination campaign were estimated to assess the cost-effectiveness of OCV for this particular campaign from both the health care provider and the societal perspective. Methodology/Principal Findings Public and private COI were obtained from interviews with local experts, with patients from three outbreaks and from reports and record review. Cost data for the vaccination campaign were collected based on actual expenditure and planned budget data. A static cohort of 50,000 individuals was examined, including herd protection. Primary outcome measures were incremental cost-effectiveness ratios (ICER) per death, per case and per disability-adjusted life-year (DALY) averted. One-way sensitivity and threshold analyses were conducted. The ICER was evaluated with regard to WHO criteria for cost-effectiveness. Base-case ICERs were USD 750,000 per death averted, USD 6,000 per case averted and USD 30,000 per DALY averted, without differences between the health care provider and the societal perspective. Threshold analyses using Shanchol and assuming high incidence and case-fatality rate indicated that the purchase price per course would have to be as low as USD 1.2 to render the mass vaccination campaign cost-effective from a health care provider perspective (societal perspective: USD 1.3). Conclusions/Significance Based on empirical and site-specific cost and effectiveness data from Zanzibar, the 2009 mass vaccination campaign was cost-ineffective mainly due to the relatively high OCV purchase price and a relatively low incidence. However, mass vaccination campaigns in Zanzibar to control endemic cholera may meet criteria for cost

  1. Chloroplast-derived vaccine antigens confer dual immunity against cholera and malaria by oral or injectable delivery.

    Science.gov (United States)

    Davoodi-Semiromi, Abdoreza; Schreiber, Melissa; Nalapalli, Samson; Verma, Dheeraj; Singh, Nameirakpam D; Banks, Robert K; Chakrabarti, Debopam; Daniell, Henry

    2010-02-01

    Cholera and malaria are major diseases causing high mortality. The only licensed cholera vaccine is expensive; immunity is lost in children within 3 years and adults are not fully protected. No vaccine is yet available for malaria. Therefore, in this study, the cholera toxin-B subunit (CTB) of Vibrio cholerae fused to malarial vaccine antigens apical membrane antigen-1 (AMA1) and merozoite surface protein-1 (MSP1) was expressed in lettuce and tobacco chloroplasts. Southern blot analysis confirmed homoplasmy and stable integration of transgenes. CTB-AMA1 and CTB-MSP1 fusion proteins accumulated up to 13.17% and 10.11% (total soluble protein, TSP) in tobacco and up to 7.3% and 6.1% (TSP) in lettuce, respectively. Nine groups of mice (n = 10/group) were immunized subcutaneously (SQV) or orally (ORV) with purified antigens or transplastomic tobacco leaves. Significant levels of antigen-specific antibody titres of immunized mice completely inhibited proliferation of the malarial parasite and cross-reacted with the native parasite proteins in immunoblots and immunofluorescence studies. Protection against cholera toxin challenge in both ORV (100%) and SQV (89%) mice correlated with CTB-specific titres of intestinal, serum IgA and IgG1 in ORV and only IgG1 in SQV mice, but no other immunoglobulin. Increasing numbers of interleukin-10(+) T cell but not Foxp3(+) regulatory T cells, suppression of interferon-gamma and absence of interleukin-17 were observed in protected mice, suggesting that immunity is conferred via the Tr1/Th2 immune response. Dual immunity against two major infectious diseases provided by chloroplast-derived vaccine antigens for long-term (>300 days, 50% of mouse life span) offers a realistic platform for low cost vaccines and insight into mucosal and systemic immunity.

  2. Mass vaccination with a new, less expensive oral cholera vaccine using public health infrastructure in India: the Odisha model.

    Science.gov (United States)

    Kar, Shantanu K; Sah, Binod; Patnaik, Bikash; Kim, Yang Hee; Kerketta, Anna S; Shin, Sunheang; Rath, Shyam Bandhu; Ali, Mohammad; Mogasale, Vittal; Khuntia, Hemant K; Bhattachan, Anuj; You, Young Ae; Puri, Mahesh K; Lopez, Anna Lena; Maskery, Brian; Nair, Gopinath B; Clemens, John D; Wierzba, Thomas F

    2014-02-01

    The substantial morbidity and mortality associated with recent cholera outbreaks in Haiti and Zimbabwe, as well as with cholera endemicity in countries throughout Asia and Africa, make a compelling case for supplementary cholera control measures in addition to existing interventions. Clinical trials conducted in Kolkata, India, have led to World Health Organization (WHO)-prequalification of Shanchol, an oral cholera vaccine (OCV) with a demonstrated 65% efficacy at 5 years post-vaccination. However, before this vaccine is widely used in endemic areas or in areas at risk of outbreaks, as recommended by the WHO, policymakers will require empirical evidence on its implementation and delivery costs in public health programs. The objective of the present report is to describe the organization, vaccine coverage, and delivery costs of mass vaccination with a new, less expensive OCV (Shanchol) using existing public health infrastructure in Odisha, India, as a model. All healthy, non-pregnant residents aged 1 year and above residing in selected villages of the Satyabadi block (Puri district, Odisha, India) were invited to participate in a mass vaccination campaign using two doses of OCV. Prior to the campaign, a de jure census, micro-planning for vaccination and social mobilization activities were implemented. Vaccine coverage for each dose was ascertained as a percentage of the censused population. The direct vaccine delivery costs were estimated by reviewing project expenditure records and by interviewing key personnel. The mass vaccination was conducted during May and June, 2011, in two phases. In each phase, two vaccine doses were given 14 days apart. Sixty-two vaccination booths, staffed by 395 health workers/volunteers, were established in the community. For the censused population, 31,552 persons (61% of the target population) received the first dose and 23,751 (46%) of these completed their second dose, with a drop-out rate of 25% between the two doses. Higher

  3. Biomarkers of Environmental Enteropathy are Positively Associated with Immune Responses to an Oral Cholera Vaccine in Bangladeshi Children.

    Directory of Open Access Journals (Sweden)

    Muhammad Ikhtear Uddin

    2016-11-01

    Full Text Available Environmental enteropathy (EE is a poorly understood condition that refers to chronic alterations in intestinal permeability, absorption, and inflammation, which mainly affects young children in resource-limited settings. Recently, EE has been linked to suboptimal oral vaccine responses in children, although immunological mechanisms are poorly defined. The objective of this study was to determine host factors associated with immune responses to an oral cholera vaccine (OCV. We measured antibody and memory T cell immune responses to cholera antigens, micronutrient markers in blood, and EE markers in blood and stool from 40 Bangladeshi children aged 3-14 years who received two doses of OCV given 14 days apart. EE markers included stool myeloperoxidase (MPO and alpha anti-trypsin (AAT, and plasma endotoxin core antibody (EndoCab, intestinal fatty acid binding protein (i-FABP, and soluble CD14 (sCD14. We used multiple linear regression analysis with LASSO regularization to identify host factors, including EE markers, micronutrient (nutritional status, age, and HAZ score, predictive for each response of interest. We found stool MPO to be positively associated with IgG antibody responses to the B subunit of cholera toxin (P = 0.03 and IgA responses to LPS (P = 0.02; plasma sCD14 to be positively associated with LPS IgG responses (P = 0.07; plasma i-FABP to be positively associated with LPS IgG responses (P = 0.01 and with memory T cell responses specific to cholera toxin (P = 0.01; stool AAT to be negatively associated with IL-10 (regulatory T cell responses specific to cholera toxin (P = 0.02, and plasma EndoCab to be negatively associated with cholera toxin-specific memory T cell responses (P = 0.02. In summary, in a cohort of children 3-14 years old, we demonstrated that the majority of biomarkers of environmental enteropathy were positively associated with immune responses after vaccination with an OCV.

  4. Feasibility and acceptability of oral cholera vaccine mass vaccination campaign in response to an outbreak and floods in Malawi.

    Science.gov (United States)

    Msyamboza, Kelias Phiri; M'bang'ombe, Maurice; Hausi, Hannah; Chijuwa, Alexander; Nkukumila, Veronica; Kubwalo, Hudson Wenji; Desai, Sachin; Pezzoli, Lorenzo; Legros, Dominique

    2016-01-01

    Despite some improvement in provision of safe drinking water, proper sanitation and hygiene promotion, cholera still remains a major public health problem in Malawi with outbreaks occurring almost every year since 1998. In response to 2014/2015 cholera outbreak, ministry of health and partners made a decision to assess the feasibility and acceptability of conducting a mass oral cholera vaccine (OCV) as an additional public health measure. This paper highlights the burden of the 2014/15 cholera outbreak, successes and challenges of OCV campaign conducted in March and April 2015. This was a documentation of the first OCV campaign conducted in Malawi. The campaign targeted over 160,000 people aged one year or more living in 19 camps of people internally displaced by floods and their surrounding communities in Nsanje district. It was a reactive campaign as additional measure to improved water, sanitation and hygiene in response to the laboratory confirmed cholera outbreak. During the first round of the OCV campaign conducted from 30 March to 4 April 2015, a total of 156,592 (97.6%) people out of 160,482 target population received OCV. During the second round (20 to 25 April 2015), a total of 137,629 (85.8%) people received OCV. Of these, 108,247 (67.6%) people received their second dose while 29,382 (18.3%) were their first dose. Of the 134,836 people with known gender and sex who received 1 or 2 doses, 54.4% were females and over half (55.4%) were children under the age of 15 years. Among 108,237 people who received 2 doses (fully immunized), 54.4% were females and 51.9% were children under 15 years of age. No severe adverse event following immunization was reported. The main reason for non-vaccination or failure to take the 2 doses was absence during the period of the campaign. This documentation has demonstrated that it was feasible, acceptable by the community to conduct a large-scale mass OCV campaign in Malawi within five weeks. Of 320,000 OCV doses received

  5. The global introduction of inactivated polio vaccine can circumvent the oral polio vaccine paradox

    NARCIS (Netherlands)

    Heinsbroek, E.; Ruitenberg, E.J.

    2010-01-01

    This literature review identifies the factors that influence the decision to introduce inactivated polio vaccine (IPV) in developing countries as opposed to the policy of vaccine cessation. Attenuated viruses in the oral polio vaccine (OPV) can replicate, revert to neurovirulence and become

  6. 5 year efficacy of a bivalent killed whole-cell oral cholera vaccine in Kolkata, India: a cluster-randomised, double-blind, placebo-controlled trial.

    Science.gov (United States)

    Bhattacharya, Sujit K; Sur, Dipika; Ali, Mohammad; Kanungo, Suman; You, Young Ae; Manna, Byomkesh; Sah, Binod; Niyogi, Swapan K; Park, Jin Kyung; Sarkar, Banwarilal; Puri, Mahesh K; Kim, Deok Ryun; Deen, Jacqueline L; Holmgren, Jan; Carbis, Rodney; Dhingra, Mandeep Singh; Donner, Allan; Nair, G Balakrish; Lopez, Anna Lena; Wierzba, Thomas F; Clemens, John D

    2013-12-01

    Efficacy and safety of a two-dose regimen of bivalent killed whole-cell oral cholera vaccine (Shantha Biotechnics, Hyderabad, India) to 3 years is established, but long-term efficacy is not. We aimed to assess protective efficacy up to 5 years in a slum area of Kolkata, India. In our double-blind, cluster-randomised, placebo-controlled trial, we assessed incidence of cholera in non-pregnant individuals older than 1 year residing in 3933 dwellings (clusters) in Kolkata, India. We randomly allocated participants, by dwelling, to receive two oral doses of modified killed bivalent whole-cell cholera vaccine or heat-killed Escherichia coli K12 placebo, 14 days apart. Randomisation was done by use of a computer-generated sequence in blocks of four. The primary endpoint was prevention of episodes of culture-confirmed Vibrio cholerae O1 diarrhoea severe enough for patients to seek treatment in a health-care facility. We identified culture-confirmed cholera cases among participants seeking treatment for diarrhoea at a study clinic or government hospital between 14 days and 1825 days after receipt of the second dose. We assessed vaccine protection in a per-protocol population of participants who had completely ingested two doses of assigned study treatment. 69 of 31 932 recipients of vaccine and 219 of 34 968 recipients of placebo developed cholera during 5 year follow-up (incidence 2·2 per 1000 in the vaccine group and 6·3 per 1000 in the placebo group). Cumulative protective efficacy of the vaccine at 5 years was 65% (95% CI 52-74; pcholera vaccines. Established long-term efficacy of this vaccine could assist policy makers formulate rational vaccination strategies to reduce overall cholera burden in endemic settings. Bill & Melinda Gates Foundation and the governments of South Korea and Sweden. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Cholera Treatment

    Science.gov (United States)

    ... Diagnosis and Detection Laboratory Testing for Cholera Treatment Rehydration Therapy Antibiotic Treatment Zinc Treatment Prevention & Control Five ... page for current cholera treatment recommendations. Cholera Treatments Rehydration therapy , meaning prompt restoration of lost fluids and ...

  8. Vibrio cholerae Infection of Drosophilamelanogaster Mimics the Human Disease Cholera.

    Directory of Open Access Journals (Sweden)

    2005-09-01

    Full Text Available Cholera, the pandemic diarrheal disease caused by the gram-negative bacterium Vibrio cholerae, continues to be a major public health challenge in the developing world. Cholera toxin, which is responsible for the voluminous stools of cholera, causes constitutive activation of adenylyl cyclase, resulting in the export of ions into the intestinal lumen. Environmental studies have demonstrated a close association between V. cholerae and many species of arthropods including insects. Here we report the susceptibility of the fruit fly, Drosophila melanogaster, to oral V. cholerae infection through a process that exhibits many of the hallmarks of human disease: (i death of the fly is dependent on the presence of cholera toxin and is preceded by rapid weight loss; (ii flies harboring mutant alleles of either adenylyl cyclase, Gsalpha, or the Gardos K channel homolog SK are resistant to V. cholerae infection; and (iii ingestion of a K channel blocker along with V. cholerae protects wild-type flies against death. In mammals, ingestion of as little as 25 mug of cholera toxin results in massive diarrhea. In contrast, we found that ingestion of cholera toxin was not lethal to the fly. However, when cholera toxin was co-administered with a pathogenic strain of V. cholerae carrying a chromosomal deletion of the genes encoding cholera toxin, death of the fly ensued. These findings suggest that additional virulence factors are required for intoxication of the fly that may not be essential for intoxication of mammals. Furthermore, we demonstrate for the first time the mechanism of action of cholera toxin in a whole organism and the utility of D. melanogaster as an accurate, inexpensive model for elucidation of host susceptibility to cholera.

  9. Peracetic Acid Treatment Generates Potent Inactivated Oral Vaccines from a Broad Range of Culturable Bacterial Species

    Science.gov (United States)

    Moor, Kathrin; Wotzka, Sandra Y.; Toska, Albulena; Diard, Médéric; Hapfelmeier, Siegfried; Slack, Emma

    2016-01-01

    Our mucosal surfaces are the main sites of non-vector-borne pathogen entry, as well as the main interface with our commensal microbiota. We are still only beginning to understand how mucosal adaptive immunity interacts with commensal and pathogenic microbes to influence factors such as infectivity, phenotypic diversity, and within-host evolution. This is in part due to difficulties in generating specific mucosal adaptive immune responses without disrupting the mucosal microbial ecosystem itself. Here, we present a very simple tool to generate inactivated mucosal vaccines from a broad range of culturable bacteria. Oral gavage of 1010 peracetic acid-inactivated bacteria induces high-titer-specific intestinal IgA in the absence of any measurable inflammation or species invasion. As a proof of principle, we demonstrate that this technique is sufficient to provide fully protective immunity in the murine model of invasive non-typhoidal Salmonellosis, even in the face of severe innate immune deficiency. PMID:26904024

  10. Neighborhood-targeted and case-triggered use of a single dose of oral cholera vaccine in an urban setting: Feasibility and vaccine coverage.

    Science.gov (United States)

    Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Muller, Vincent; Llosa, Augusto E; Uzzeni, Florent; Luquero, Francisco J; Ciglenecki, Iza; Azman, Andrew S

    2017-06-01

    In June 2015, a cholera outbreak was declared in Juba, South Sudan. In addition to standard outbreak control measures, oral cholera vaccine (OCV) was proposed. As sufficient doses to cover the at-risk population were unavailable, a campaign using half the standard dosing regimen (one-dose) targeted high-risk neighborhoods and groups including neighbors of suspected cases. Here we report the operational details of this first public health use of a single-dose regimen of OCV and illustrate the feasibility of conducting highly targeted vaccination campaigns in an urban area. Neighborhoods of the city were prioritized for vaccination based on cumulative attack rates, active transmission and local knowledge of known cholera risk factors. OCV was offered to all persons older than 12 months at 20 fixed sites and to select groups, including neighbors of cholera cases after the main campaign ('case-triggered' interventions), through mobile teams. Vaccination coverage was estimated by multi-stage surveys using spatial sampling techniques. 162,377 individuals received a single-dose of OCV in the targeted neighborhoods. In these neighborhoods vaccine coverage was 68.8% (95% Confidence Interval (CI), 64.0-73.7) and was highest among children ages 5-14 years (90.0%, 95% CI 85.7-94.3), with adult men being less likely to be vaccinated than adult women (Relative Risk 0.81, 95% CI: 0.68-0.96). In the case-triggered interventions, each lasting 1-2 days, coverage varied (range: 30-87%) with an average of 51.0% (95% CI 41.7-60.3). Vaccine supply constraints and the complex realities where cholera outbreaks occur may warrant the use of flexible alternative vaccination strategies, including highly-targeted vaccination campaigns and single-dose regimens. We showed that such campaigns are feasible. Additional work is needed to understand how and when to use different strategies to best protect populations against epidemic cholera.

  11. A cost-benefit analysis of programmatic use of CVD 103-HgR live oral cholera vaccine in a high-risk population.

    Science.gov (United States)

    Cookson, S T; Stamboulian, D; Demonte, J; Quero, L; Martinez de Arquiza, C; Aleman, A; Lepetic, A; Levine, M M

    1997-02-01

    Cholera spread to Latin America in 1991; subsequently, cholera vaccination was considered as an interim intervention until long-term solutions involving improved water supplies and sanitation could be introduced. Three successive summer cholera outbreaks in northern Argentina and the licensing of the new single-dose oral cholera vaccine, CVD 103-HgR, raised questions of the cost and benefit of using this new vaccine. This study explored the potential benefits to the Argentine Ministry of Health of treatment costs averted, versus the costs of vaccination with CVD 103-HgR in the relatively confined population of northern Argentina affected by the cholera outbreaks. Water supplies and sanitation in this area are poor but a credible infrastructure for vaccine delivery exists. In our cost-benefit model of a 3-year period (1992-1994) with an annual incidence of 2.5 case-patients per 1000 population and assumptions of vaccine efficacy of 75% and coverage of 75%, vaccination of targeted high risk groups would prevent 1265 cases. Assuming a cost of US$602 per treated case and of US$1.50 per dose of vaccine, the total discounted savings from use of vaccine in the targeted groups would be US$132,100. The projected savings would be altered less by vaccine coverage (range 75-90%) or efficacy (60-85%) changes than by disease incidence changes. Our analysis underestimated the true costs of cholera in Argentina because we included only medical expenditures; Indirect losses to trade and tourism had the greatest economic impact. However, vaccination with CVD 103-HgR was still cost-beneficial in the base case.

  12. Good manufacturing practices production of a purification-free oral cholera vaccine expressed in transgenic rice plants.

    Science.gov (United States)

    Kashima, Koji; Yuki, Yoshikazu; Mejima, Mio; Kurokawa, Shiho; Suzuki, Yuji; Minakawa, Satomi; Takeyama, Natsumi; Fukuyama, Yoshiko; Azegami, Tatsuhiko; Tanimoto, Takeshi; Kuroda, Masaharu; Tamura, Minoru; Gomi, Yasuyuki; Kiyono, Hiroshi

    2016-03-01

    The first Good Manufacturing Practices production of a purification-free rice-based oral cholera vaccine (MucoRice-CTB) from transgenic plants in a closed cultivation system yielded a product meeting regulatory requirements. Despite our knowledge of their advantages, plant-based vaccines remain unavailable for human use in both developing and industrialized countries. A leading, practical obstacle to their widespread use is producing plant-based vaccines that meet governmental regulatory requirements. Here, we report the first production according to current Good Manufacturing Practices of a rice-based vaccine, the cholera vaccine MucoRice-CTB, at an academic institution. To this end, we established specifications and methods for the master seed bank (MSB) of MucoRice-CTB, which was previously generated as a selection-marker-free line, evaluated its propagation, and given that the stored seeds must be renewed periodically. The production of MucoRice-CTB incorporated a closed hydroponic system for cultivating the transgenic plants, to minimize variations in expression and quality during vaccine manufacture. This type of molecular farming factory can be operated year-round, generating three harvests annually, and is cost- and production-effective. Rice was polished to a ratio of 95 % and then powdered to produce the MucoRice-CTB drug substance, and the identity, potency, and safety of the MucoRice-CTB product met pre-established release requirements. The formulation of MucoRice-CTB made by fine-powdering of drug substance and packaged in an aluminum pouch is being evaluated in a physician-initiated phase I study.

  13. Peru-15 (Choleragarde(®)), a live attenuated oral cholera vaccine, is safe and immunogenic in human immunodeficiency virus (HIV)-seropositive adults in Thailand.

    Science.gov (United States)

    Ratanasuwan, W; Kim, Y H; Sah, B K; Suwanagool, S; Kim, D R; Anekthananon, A; Lopez, A L; Techasathit, W; Grahek, S L; Clemens, J D; Wierzba, T F

    2015-09-11

    Many areas with endemic and epidemic cholera report significant levels of HIV transmission. According to the World Health Organization (WHO), over 95% of reported cholera cases occur in Africa, which also accounts for nearly 70% of people living with HIV/AIDS globally. Peru-15, a promising single dose live attenuated oral cholera vaccine (LA-OCV), was previously found to be safe and immunogenic in cholera endemic areas. However, no data on the vaccine's safety among HIV-seropositive adults had been collected. This study was a double-blinded, individually randomized, placebo-controlled trial enrolling HIV-seropositive adults, 18-45 years of age, conducted in Bangkok, Thailand, to assess the safety of Peru-15 in a HIV-seropositive cohort. 32 HIV infected subjects were randomized to receive either a single oral dose of the Peru-15 vaccine with a buffer or a placebo (buffer only). No serious adverse events were reported during the follow-up period in either group. The geometric mean fold (GMF) rise in V. cholerae O1 El Tor specific antibody titers between baseline and 7 days after dosing was 32.0 (pcholerae was isolated from the stool of one vaccinee, and found to be genetically identical to the Peru-15 vaccine strain. There were no significant changes in HIV viral load or CD4 T-cell counts between vaccine and placebo groups. Peru-15 was shown to be safe and immunogenic in HIV-seropositive Thai adults. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Traffic of antibody-secreting cells after immunization with a liposome-associated, CpG-ODN-adjuvanted oral cholera vaccine.

    Science.gov (United States)

    Somroop, Srinuan; Tongtawe, Pongsri; Chaisri, Urai; Tapchaisri, Pramuan; Chongsa-nguan, Manas; Srimanote, Potjanee; Chaicumpa, Wanpen

    2006-12-01

    An oral cholera vaccine made up of heat-treated recombinant cholera toxin (rCT), V. cholerae lipopolysaccharide (LPS), and recombinant toxin-co-regulated pili subunit A (rTcpA), entrapped in liposomes in the presence of unmethylated bacterial CpG-DNA (ODN#1826) was used to orally immunize a group of eight week old rats. A booster dose was given 14 days later. Control rats received placebo (vaccine diluent). The kinetics of the immune response were investigated by enumerating the antigen specific-antibody secreting cells (ASC) in the blood circulation and intestinal lamina propria using the ELISPOT assay and a histo-immunofluorescence assay (IFA), respectively. ASC of all antigenic specificities were detected in the blood of the vaccinated rats as early as two days after the booster dose. The numbers of LPS-ASC and TcpA-ASC in the blood were at their peak at day 3 post booster while the number of CT-ASC was highest at day 4 after the booster immunization. At day 13 post immunization, no ASC were detected in the blood. A several fold increase in the number of ASC of all antigenic specificities in the lamina propria above the background numbers of the control animals were found in all vaccinated rats at days 6 and 13 post booster (earlier and later time points were not studied). Vibriocidal antibody and specific antibodies to CT, LPS and TcpA were detected in 57.1% and 52.4%, 14.3%, and 19.0% of the orally vaccinated rats, respectively. The data indicated that rats orally primed with the vaccine could produce a rapid anamnestic response after re-exposure to the V. cholerae antigens. Thus, a single dose of the vaccine is expected to elicit a similar anamnestic immune response in people from cholera endemic areas who have been naturally primed to V. cholerae antigens, while two doses at a 14 day interval should be adequate for a traveler to a disease endemicarea.

  15. p53 inactivation in chewing tobacco-induced oral cancers and leukoplakias from India.

    Science.gov (United States)

    Saranath, D; Tandle, A T; Teni, T R; Dedhia, P M; Borges, A M; Parikh, D; Sanghavi, V; Mehta, A R

    1999-05-01

    The inactivation of p53 tumour suppressor gene vis-á-vis point mutation, overexpression and degradation due to Human Papilloma virus (HPV) 16/18 infection, was examined in chewing tobacco-associated oral cancers and oral leukoplakias from India. The analysis of mutations was assessed by polymerase chain reaction (PCR) with single strand conformation polymorphism (PCR-SSCP) of exons 5-9 on DNA from 83 oral cancer cases, and the mutations confirmed by direct nucleotide sequencing of the PCR products. p53 protein expression was evaluated by immunohistochemical analysis on paraffin-embedded sections of 62 representative oral cancer biopsies and 22 leukoplakias, using p53-specific monoclonal antibody DO-7. The presence of HPV16/18 was detected in the 83 oral cancer cases by PCR analysis using HPV L1 consensus sequences, followed by Southern hybridization with type-specific oligonucleotide probes. Forty-six per cent (38/83) of oral cancer tumours showed p53 alterations, with 17% (14/83) showing point mutations, 37% (23/62) with overexpression and 25% (21/83) with presence of HPV16 wherein the E6 HPV16 protein degrades p53. HPV18 was not detected in any of the samples. Ninety-two per cent concordance was observed between missense point mutations and overexpression of p53 protein. A significant correlation was not observed between p53 alterations in oral cancer and clinico-pathological profile of the patients. Twenty-seven per cent (6/22) of oral leukoplakias showed p53 overexpression. The overall p53 alterations in oral cancer tissues and oral lesions are comparable to data from the oral cancers reported in the Western countries with smoking and alcohol-associated oral cancers, and suggest a critical role for p53 gene in a significant proportion of oral cancers from India. The overexpression of p53 protein in leukoplakias may serve as a valuable biomarker for identifying individuals at high risk of transformation to malignant phenotype.

  16. First Outbreak Response Using an Oral Cholera Vaccine in Africa: Vaccine Coverage, Acceptability and Surveillance of Adverse Events, Guinea, 2012

    Science.gov (United States)

    Luquero, Francisco J.; Grout, Lise; Ciglenecki, Iza; Sakoba, Keita; Traore, Bala; Heile, Melat; Dialo, Alpha Amadou; Itama, Christian; Serafini, Micaela; Legros, Dominique; Grais, Rebecca F.

    2013-01-01

    Background Despite World Health Organization (WHO) prequalification of two safe and effective oral cholera vaccines (OCV), concerns about the acceptability, potential diversion of resources, cost and feasibility of implementing timely campaigns has discouraged their use. In 2012, the Ministry of Health of Guinea, with the support of Médecins Sans Frontières organized the first mass vaccination campaign using a two-dose OCV (Shanchol) as an additional control measure to respond to the on-going nationwide epidemic. Overall, 316,250 vaccines were delivered. Here, we present the results of vaccination coverage, acceptability and surveillance of adverse events. Methodology/Principal Findings We performed a cross-sectional cluster survey and implemented adverse event surveillance. The study population included individuals older than 12 months, eligible for vaccination, and residing in the areas targeted for vaccination (Forécariah and Boffa, Guinea). Data sources were household interviews with verification by vaccination card and notifications of adverse events from surveillance at vaccination posts and health centres. In total 5,248 people were included in the survey, 3,993 in Boffa and 1,255 in Forécariah. Overall, 89.4% [95%CI:86.4–91.8%] and 87.7% [95%CI:84.2–90.6%] were vaccinated during the first round and 79.8% [95%CI:75.6–83.4%] and 82.9% [95%CI:76.6–87.7%] during the second round in Boffa and Forécariah respectively. The two dose vaccine coverage (including card and oral reporting) was 75.8% [95%CI: 71.2–75.9%] in Boffa and 75.9% [95%CI: 69.8–80.9%] in Forécariah respectively. Vaccination coverage was higher in children. The main reason for non-vaccination was absence. No severe adverse events were notified. Conclusions/Significance The well-accepted mass vaccination campaign reached high coverage in a remote area with a mobile population. Although OCV should not be foreseen as the long-term solution for global cholera control, they should be

  17. First outbreak response using an oral cholera vaccine in Africa: vaccine coverage, acceptability and surveillance of adverse events, Guinea, 2012.

    Directory of Open Access Journals (Sweden)

    Francisco J Luquero

    Full Text Available BACKGROUND: Despite World Health Organization (WHO prequalification of two safe and effective oral cholera vaccines (OCV, concerns about the acceptability, potential diversion of resources, cost and feasibility of implementing timely campaigns has discouraged their use. In 2012, the Ministry of Health of Guinea, with the support of Médecins Sans Frontières organized the first mass vaccination campaign using a two-dose OCV (Shanchol as an additional control measure to respond to the on-going nationwide epidemic. Overall, 316,250 vaccines were delivered. Here, we present the results of vaccination coverage, acceptability and surveillance of adverse events. METHODOLOGY/PRINCIPAL FINDINGS: We performed a cross-sectional cluster survey and implemented adverse event surveillance. The study population included individuals older than 12 months, eligible for vaccination, and residing in the areas targeted for vaccination (Forécariah and Boffa, Guinea. Data sources were household interviews with verification by vaccination card and notifications of adverse events from surveillance at vaccination posts and health centres. In total 5,248 people were included in the survey, 3,993 in Boffa and 1,255 in Forécariah. Overall, 89.4% [95%CI:86.4-91.8%] and 87.7% [95%CI:84.2-90.6%] were vaccinated during the first round and 79.8% [95%CI:75.6-83.4%] and 82.9% [95%CI:76.6-87.7%] during the second round in Boffa and Forécariah respectively. The two dose vaccine coverage (including card and oral reporting was 75.8% [95%CI: 71.2-75.9%] in Boffa and 75.9% [95%CI: 69.8-80.9%] in Forécariah respectively. Vaccination coverage was higher in children. The main reason for non-vaccination was absence. No severe adverse events were notified. CONCLUSIONS/SIGNIFICANCE: The well-accepted mass vaccination campaign reached high coverage in a remote area with a mobile population. Although OCV should not be foreseen as the long-term solution for global cholera control, they

  18. Improving immunization approaches to cholera.

    Science.gov (United States)

    Saha, Amit; Rosewell, Alexander; Hayen, Andrew; MacIntyre, C Raina; Qadri, Firdausi

    2017-03-01

    Cholera's impact is greatest in resource-limited countries. In the last decade several large epidemics have led to a global push to improve and implement the tools for cholera prevention and control. Areas covered: PubMed, Google Scholar and the WHO website were searched to review the literature and summarize the current status of cholera vaccines to make recommendations on improving immunization approaches to cholera. Oral cholera vaccines (OCVs) have demonstrated their effectiveness in endemic, outbreak response and emergency settings, highlighting their potential for wider adoption. While two doses of the currently available OCVs are recommended by manufacturers, a single dose would be easier to implement. Encouragingly, recent studies have shown that cold chain requirements may no longer be essential. The establishment of the global OCV stockpile in 2013 has been a major advance in cholera preparedness. New killed and live-attenuated vaccines are being actively explored as candidate vaccines for endemic settings and/or as a traveller's vaccine. The recent advances in cholera vaccination approaches should be considered in the global cholera control strategy. Expert commentary: The development of affordable cholera vaccines is a major success to improve cholera control. New vaccines and country specific interventions will further reduce the burden of this disease globally.

  19. Optimized oral cholera vaccine distribution strategies to minimize disease incidence: A mixed integer programming model and analysis of a Bangladesh scenario.

    Science.gov (United States)

    Smalley, Hannah K; Keskinocak, Pinar; Swann, Julie; Hinman, Alan

    2015-11-17

    In addition to improved sanitation, hygiene, and better access to safe water, oral cholera vaccines can help to control the spread of cholera in the short term. However, there is currently no systematic method for determining the best allocation of oral cholera vaccines to minimize disease incidence in a population where the disease is endemic and resources are limited. We present a mathematical model for optimally allocating vaccines in a region under varying levels of demographic and incidence data availability. The model addresses the questions of where, when, and how many doses of vaccines to send. Considering vaccine efficacies (which may vary based on age and the number of years since vaccination), we analyze distribution strategies which allocate vaccines over multiple years. Results indicate that, given appropriate surveillance data, targeting age groups and regions with the highest disease incidence should be the first priority, followed by other groups primarily in order of disease incidence, as this approach is the most life-saving and cost-effective. A lack of detailed incidence data results in distribution strategies which are not cost-effective and can lead to thousands more deaths from the disease. The mathematical model allows for what-if analysis for various vaccine distribution strategies by providing the ability to easily vary parameters such as numbers and sizes of regions and age groups, risk levels, vaccine price, vaccine efficacy, production capacity and budget. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Mass vaccination with a two-dose oral cholera vaccine in a long-standing refugee camp, Thailand.

    Science.gov (United States)

    Phares, Christina R; Date, Kashmira; Travers, Philippe; Déglise, Carole; Wongjindanon, Nuttapong; Ortega, Luis; Bhuket, Ponchanok Rattanadilok Na

    2016-01-02

    During 2005-2012, surveillance in Maela refugee camp, Thailand, identified four cholera outbreaks, with rates up to 10.7 cases per 1000 refugees. In 2013, the Thailand Ministry of Public Health sponsored a two-dose oral cholera vaccine (OCV) campaign for the approximately 46,000 refugees living in Maela. We enumerated the target population (refugees living in Maela who are ≥1 year old and not pregnant) in a census three months before the campaign and issued barcoded OCV cards to each individual. We conducted the campaign using a fixed-post strategy during two eight-day rounds plus one two-day round for persons who had missed their second dose and recorded vaccine status for each individual. To identify factors associated with no vaccination (versus at least one dose) and those associated with adverse events following immunization (AEFI), we used separate marginal log-binomial regression models with robust variance estimates to account for household clustering. A total of 63,057 OCV doses were administered to a target population of 43,485 refugees. An estimated 35,399 (81%) refugees received at least one dose and 27,658 (64%) received two doses. A total of 993 additional doses (1.5%) were wasted including 297 that were spat out. Only 0.05% of refugees, mostly children, could not be vaccinated due to repeated spitting. Characteristics associated with no vaccination (versus at least one dose) included age ≥15 years (versus 1-14 years), Karen ethnicity (versus any other ethnicity) and, only among adults 15-64 years old, male sex. Passive surveillance identified 84 refugees who experienced 108 AEFI including three serious but coincidental events. The most frequent AEFI were nausea (49%), dizziness (38%), and fever (30%). Overall, AEFI were more prevalent among young children and older adults. Our results suggest that mass vaccination in refugee camps with a two-dose OCV is readily achievable and AEFI are few. Published by Elsevier Ltd.

  1. Oral cholera vaccine coverage in hard-to-reach fishermen communities after two mass Campaigns, Malawi, 2016.

    Science.gov (United States)

    Sauvageot, Delphine; Saussier, Christel; Gobeze, Abebe; Chipeta, Sikhona; Mhango, Innocent; Kawalazira, Gift; Mengel, Martin A; Legros, Dominique; Cavailler, Philippe; M'bang'ombe, Maurice

    2017-09-12

    From December 2015 to August 2016, a large epidemic of cholera affected the fishermen of Lake Chilwa in Malawi. A first reactive Oral Cholera Vaccines (OCV) campaign was organized, in February, in a 2km radius of the lake followed by a preemptive one, conducted in November, in a 25km radius. We present the vaccine coverage reached in hard-to-reach population using simplified delivery strategies. We conducted two-stage random-sampling cross-sectional surveys among individuals living in a 2km and 25km radius of Lake Chilwa (islands and floating homes included). Individuals aged 12months and older from Machinga and Zomba districts were sampled: 43 clusters of 14 households were surveyed. Simplified strategies were used for those living in islands and floating homes: self- delivery and community-supervised delivery of the second dose. Vaccine coverage (VC) for at-least-two-doses was estimated taking into account sampling weights and design effects. A total of 1176 households were surveyed (2.7% of non-response). Among the 2833 individuals living in the 2km radius of Lake and the 2915 in the 25km radius: 457 (16.1%) and 239 (8.2%) lived in floating homes or on islands at some point in the year, respectively. For the overall population, VC was 75.6% and 54.2%, respectively. In the 2km radius, VC was 92.2% for those living on the lake at some point of the year: 271 (64.8%) used the simplified strategies. The main reasons for non-vaccination were absence during the campaign and vaccine shortage. Few adverse events occurring in the 24h following vaccination was reported. We reached a high two-dose coverage of the most at-risk population using simplified delivery strategies. Because of the high fishermen mobility, regular catch-up campaigns or another strategy specifically targeting fishermen need to be assessed for more efficient vaccines use. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  2. Vibriocidal antibody responses to a bivalent killed whole-cell oral cholera vaccine in a phase III trial in Kolkata, India.

    Directory of Open Access Journals (Sweden)

    Suman Kanungo

    Full Text Available BACKGROUND: During the development of a vaccine, identification of the correlates of protection is of paramount importance for establishing an objective criterion for the protective performance of the vaccine. However, the ascertainment of correlates of immunity conferred by any vaccine is a difficult task. METHODS: While conducting a phase three double-blind, cluster-randomized, placebo-controlled trial of a bivalent killed whole-cell oral cholera vaccine in Kolkata, we evaluated the immunogenicity of the vaccine in a subset of participants. Randomly chosen participants (recipients of vaccine or placebo were invited to provide blood samples at baseline, 14 days after the second dose and one year after the first dose. At these time points, serum geometric mean titers (GMT of vibriocidal antibodies and seroconversion rates for vaccine and placebo arms were calculated and compared across the age strata (1 to 5 years, 5 to 15 years and more than 15 years as well as for all age groups. RESULTS: Out of 137 subjects included in analysis, 69 were vaccinees and 68 received placebo. There were 5•7 and 5•8 geometric mean fold (GMF rises in titers to Vibrio cholerae Inaba and Ogawa, respectively at 14 days after the second dose, with 57% and 61% of vaccinees showing a four-fold or greater titer rise, respectively. After one year, the titers to Inaba and Ogawa remained 1•7 and 2•8 fold higher, respectively, compared to baseline. Serum vibriocidal antibody response to V. cholerae O139 was much lower than that to Inaba or Ogawa. No significant differences in the GMF-rises were observed among the age groups. CONCLUSIONS: The reformulated oral cholera vaccine induced a statistically significant anti-O1 Inaba and O1 Ogawa vibriocidal antibody response 14 days after vaccination, which although declined after one year remained significantly higher than baseline. Despite this decline, the vaccine remained protective five years after vaccination.

  3. Cholera in the Americas.

    Science.gov (United States)

    1991-01-01

    The cholera epidemic 1st hit South America in January 1991 in the coastal town of Chancay, Peru. In 2 weeks, it spread over 2000 km of the Pacific coast. By the end of the 1st month, it had already reached the mountains and tropical forests. By August 1991, cholera cases were reported in order of appearances in Ecuador, Colombia, Chile, Brazil, the US, Mexico, Guatemala, Bolivia, and El Salvador. Health authorities still do not know how it was introduced into South America. The case fatality rate has remained at a low of 1%, probably due to the prompt actions of health authorities in informing the public of the epidemic and what preventive cautions should be taken. This epidemic is part of the 7th pandemic which originated in Celebes, Indonesia in 1961. Cholera can spread relatively unchecked in Latin America because sewage in urban areas is not treated even though they do have sewage collection systems. The untreated wastewater enters rivers and the ocean. Consumption of raw seafood is not unusual and has been responsible for cholera infection in some cases. In fact, many countries placed import restrictions on marine products from Peru following the outbreak at a loss of $US10-$US40 million. Municipal sewage treatment facilities, especially stabilization ponds, would prevent the spread of cholera and other pathogens. In rural areas, pit latrines located away from wells can effectively dispose of human wastes. Most water supplies in Latin America are not disinfected. Disinfection drinking water with adequate levels of chlorine would effectively destroy V. cholera. If this is not possible, boiling the water for 2-3 minutes would destroy the pathogen. Any cases of cholera must be reported to PAHO. PAHO has responded to the outbreak by forming a Cholera Task Force and arranged transport of oral rehydration salts, intravenous fluids, antibiotics, and other essential medical supplies.

  4. Cholera in Children

    Science.gov (United States)

    ... oral antibiotic will be given. More serious skin infections and bacteria in the blood are treated in the hospital with intravenous antibiotics. In some cases, your child may require surgery to drain pus and damaged tissues. Prevention V cholerae can be killed by boiling, filtering, ...

  5. Cost-benefit of WC/rBS oral cholera vaccine for vaccination against ETEC-caused travelers' diarrhea.

    Science.gov (United States)

    Lundkvist, Jonas; Steffen, Robert; Jönsson, Bengt

    2009-01-01

    The most common infectious health problem encountered by travelers to countries in the developing region is travelers' diarrhea (TD), with enterotoxigenic Escherichia coli (ETEC) being the most common pathogen isolated. Although mild in most cases, the disease still leads to the loss of a significant part of a vacation or business trip. There is currently a lack of knowledge about the costs in relation to the benefits of vaccination against TD caused by ETEC, and the purposes of this study were to estimate and develop a cost-benefit analysis of vaccination using whole-cell/recombinant-B-subunit oral cholera vaccine. The consequences of the vaccination were identified and quantified in monetary terms. The cost-benefits for leisure and business travelers were assessed separately. The value of the travel was separated into the cost of the trip and of lost leisure time/business opportunities. A person with TD was in base case estimated to lose on average 3.5 days of a 7-day leisure trip and 2.5 days of a 4-day business trip. Results are presented for a Canadian traveler to endemic areas in year 2007 in US$. The average cost of a TD event was estimated at $1,460 and $1,996 for leisure and business travelers, respectively. The net value of the vaccination, however, varied with the risk of the disease. Through extensive literature searches, an updated ETEC map illustrating the proportion of ETEC-caused TD was created. The analysis indicated that vaccination would be considered cost-effective at incidence rates of ETEC-caused TD above about 13 and 9% for leisure and business travelers, respectively. It is, however, important to keep in mind that it is the value of the travel for the individual traveler that will decide if the vaccination provides good value for money.

  6. Expression of cholera toxin B–proinsulin fusion protein in lettuce and tobacco chloroplasts – oral administration protects against development of insulitis in non-obese diabetic mice

    OpenAIRE

    Ruhlman, Tracey; Ahangari, Raheleh; Devine, Andrew; Samsam, Mohtahsem; Daniell, Henry

    2007-01-01

    Lettuce and tobacco chloroplast transgenic lines expressing the cholera toxin B subunit–human proinsulin (CTB-Pins) fusion protein were generated. CTB-Pins accumulated up to ~16% of total soluble protein (TSP) in tobacco and up to ~2.5% of TSP in lettuce. Eight milligrams of powdered tobacco leaf material expressing CTB-Pins or, as negative controls, CTB–green fluorescent protein (CTB-GFP) or interferon–GFP (IFN-GFP), or untransformed leaf, were administered orally, each week for 7 weeks, to ...

  7. Systematic review of mucosal immunity induced by oral and inactivated poliovirus vaccines against virus shedding following oral poliovirus challenge.

    Directory of Open Access Journals (Sweden)

    Thomas R Hird

    Full Text Available Inactivated poliovirus vaccine (IPV may be used in mass vaccination campaigns during the final stages of polio eradication. It is also likely to be adopted by many countries following the coordinated global cessation of vaccination with oral poliovirus vaccine (OPV after eradication. The success of IPV in the control of poliomyelitis outbreaks will depend on the degree of nasopharyngeal and intestinal mucosal immunity induced against poliovirus infection. We performed a systematic review of studies published through May 2011 that recorded the prevalence of poliovirus shedding in stool samples or nasopharyngeal secretions collected 5-30 days after a "challenge" dose of OPV. Studies were combined in a meta-analysis of the odds of shedding among children vaccinated according to IPV, OPV, and combination schedules. We identified 31 studies of shedding in stool and four in nasopharyngeal samples that met the inclusion criteria. Individuals vaccinated with OPV were protected against infection and shedding of poliovirus in stool samples collected after challenge compared with unvaccinated individuals (summary odds ratio [OR] for shedding 0.13 (95% confidence interval [CI] 0.08-0.24. In contrast, IPV provided no protection against shedding compared with unvaccinated individuals (summary OR 0.81 [95% CI 0.59-1.11] or when given in addition to OPV, compared with individuals given OPV alone (summary OR 1.14 [95% CI 0.82-1.58]. There were insufficient studies of nasopharyngeal shedding to draw a conclusion. IPV does not induce sufficient intestinal mucosal immunity to reduce the prevalence of fecal poliovirus shedding after challenge, although there was some evidence that it can reduce the quantity of virus shed. The impact of IPV on poliovirus transmission in countries where fecal-oral spread is common is unknown but is likely to be limited compared with OPV.

  8. Killed Whole-Cell Oral Cholera Vaccine Induces CCL20 Secretion by Human Intestinal Epithelial Cells in the Presence of the Short-Chain Fatty Acid, Butyrate

    Directory of Open Access Journals (Sweden)

    Ju-Ri Sim

    2018-01-01

    Full Text Available Short-chain fatty acids (SCFAs, such as acetate, butyrate, and propionate, modulate immune responses in the gut. However, the effect of SCFAs on mucosal vaccine-induced immune cell migration is poorly understood. Here, we investigated whether SCFAs modulate chemokine expression induced by the killed whole-cell oral cholera vaccine, Shanchol™, in human intestinal epithelial cells. Shanchol™ induced expression of CCL2, CCL5, CCL20, and CXCL10 at the mRNA level, but not at the protein level. Interestingly, CCL20 secretion was substantially increased by co-stimulation with Shanchol™ and butyrate, while neither acetate nor propionate showed such effect. Enhanced CCL20 secretion was associated with GPR109A activation, and histone deacetylase (HDAC inhibition. In addition, co-treatment with Shanchol™ and butyrate synergistically increased the secretion of adenosine triphosphate (ATP. Moreover, CCL20 secretion was decreased by inhibiting the extracellular ATP receptor P2X7. However, neither inflammasomes nor caspases were involved in CCL20 production. The culture supernatant of cells treated with Shanchol™ and butyrate augmented human immature dendritic cell migration. Collectively, these results suggest that butyrate enhances Shanchol™-induced CCL20 production in human intestinal epithelial cells via HDAC inhibition and ATP-P2X7 signaling by activating GPR109A. These effects potentially enhance the mucosal immune responses in the gut induced by this oral cholera vaccine.

  9. [An oral chemical vaccine from the hypertoxigenic strains of the causative agent of cholera KM-76 Inaba and KM-68 Ogawa].

    Science.gov (United States)

    Dzhaparidze, M N; Naumov, A V; Nikitina, G P; Meleshchenko, M V; Dobrova, G V; Zavorotnykh, V I; Gracheva, V P; Zakharova, T L

    1991-04-01

    The material on the development of chemical vaccine, prepared from two newly formed strains (KM-76 Inaba and KM-68 Ogawa) and intended for oral administration, is presented. The conditions for the submerged cultivation of these strains have been established, which makes it possible to increase the production of choleragen 8- to 10-fold and O-antigen 3- to 4-fold in comparison with V. cholerae natural strain 569B. The maximum accumulation of neuraminidase, protease, phospholipase, along with choleragen, has been registered in the logarithmic phase and that of O-antigen, in the stationary phase of growth. The use of strains KM-76 and KM-68 has led to the fourfold increase of the specific activity of the main immunogens, thus permitting the respective increase of the yield of the oral vaccine without changes in its high capacity for the formation of specific antibodies and its low residual toxigenicity.

  10. Oral vaccination with heat inactivated Mycobacterium bovis activates the complement system to protect against tuberculosis.

    Directory of Open Access Journals (Sweden)

    Beatriz Beltrán-Beck

    Full Text Available Tuberculosis (TB remains a pandemic affecting billions of people worldwide, thus stressing the need for new vaccines. Defining the correlates of vaccine protection is essential to achieve this goal. In this study, we used the wild boar model for mycobacterial infection and TB to characterize the protective mechanisms elicited by a new heat inactivated Mycobacterium bovis vaccine (IV. Oral vaccination with the IV resulted in significantly lower culture and lesion scores, particularly in the thorax, suggesting that the IV might provide a novel vaccine for TB control with special impact on the prevention of pulmonary disease, which is one of the limitations of current vaccines. Oral vaccination with the IV induced an adaptive antibody response and activation of the innate immune response including the complement component C3 and inflammasome. Mycobacterial DNA/RNA was not involved in inflammasome activation but increased C3 production by a still unknown mechanism. The results also suggested a protective mechanism mediated by the activation of IFN-γ producing CD8+ T cells by MHC I antigen presenting dendritic cells (DCs in response to vaccination with the IV, without a clear role for Th1 CD4+ T cells. These results support a role for DCs in triggering the immune response to the IV through a mechanism similar to the phagocyte response to PAMPs with a central role for C3 in protection against mycobacterial infection. Higher C3 levels may allow increased opsonophagocytosis and effective bacterial clearance, while interfering with CR3-mediated opsonic and nonopsonic phagocytosis of mycobacteria, a process that could be enhanced by specific antibodies against mycobacterial proteins induced by vaccination with the IV. These results suggest that the IV acts through novel mechanisms to protect against TB in wild boar.

  11. Drinking cholera

    DEFF Research Database (Denmark)

    Grant, Stephen Lawrence; Tamason, Charlotte Crim; Hoque, Bilqis Amin

    2015-01-01

    . cholerae can survive in the river systems in Bangladesh; however,water sources which have been contaminated with river water are avoided as potential drinkingwater sources. Furthermore, there are no physical connecting points between the river system anddrinking water sources among the study population......, indicating that the primary driver for choleracases in Bangladesh is likely not through the contamination of saline-rich river water into drinkingwater sources.......Objectives: To measure the salinity levels of common water sources in coastal Bangladesh andexplore perceptions of water palatability among the local population to investigate the plausibility oflinking cholera outbreaks in Bangladesh with ingestion of saline-rich cholera-infected river water...

  12. [Synthesis of protective antigens during submerged cultivation of Vibrio cholerae].

    Science.gov (United States)

    Fedorova, V A; Syrova, N A; Gromova, O V; Tershkina, N E; Devdariani, Z L; Dzhaparidze, M N; Meleshchenko, M V; Dobrova, G V; Beliakova, N I; Ermakov, N M; Eliseev, Iu Iu

    2000-01-01

    The effectiveness of dot immunoanalysis for evaluating the dynamics of the synthesis of O-antigen, cholera toxin, neuraminidase, adhesin CFA1 in the process of the reactor cultivation of V. cholerae used for the production of oral chemical cholera vaccine is shown. The established regularities of the synthesis of the protective antigens of V. cholerae in the process of scaled-up cultivation are discussed.

  13. Reactive hydroxyl radical-driven oral bacterial inactivation by radio frequency atmospheric plasma

    International Nuclear Information System (INIS)

    Kang, Sung Kil; Lee, Jae Koo; Choi, Myeong Yeol; Koo, Il Gyo; Kim, Paul Y.; Kim, Yoonsun; Kim, Gon Jun; Collins, George J.; Mohamed, Abdel-Aleam H.

    2011-01-01

    We demonstrated bacterial (Streptococcus mutans) inactivation by a radio frequency power driven atmospheric pressure plasma torch with H 2 O 2 entrained in the feedstock gas. Optical emission spectroscopy identified substantial excited state OH generation inside the plasma and relative OH formation was verified by optical absorption. The bacterial inactivation rate increased with increasing OH generation and reached a maximum 5-log 10 reduction with 0.6%H 2 O 2 vapor. Generation of large amounts of toxic ozone is drawback of plasma bacterial inactivation, thus it is significant that the ozone concentration falls within recommended safe allowable levels with addition of H 2 O 2 vapor to the plasma.

  14. Cholera toxin subunit B peptide fusion proteins reveal impaired oral tolerance induction in diabetes-prone but not in diabetes-resistant mice.

    Science.gov (United States)

    Presa, Maximiliano; Ortiz, Angela Zarama; Garabatos, Nahir; Izquierdo, Cristina; Rivas, Elisa I; Teyton, Luc; Mora, Conchi; Serreze, David; Stratmann, Thomas

    2013-11-01

    The cholera toxin B subunit (CTB) has been used as adjuvant to improve oral vaccine delivery in type 1 diabetes. The effect of CTB/peptide formulations on Ag-specific CD4(+) T cells has remained largely unexplored. Here, using tetramer analysis, we investigated how oral delivery of CTB fused to two CD4(+) T-cell epitopes, the BDC-2.5 T-cell 2.5 mi mimotope and glutamic acid decarboxylase (GAD) 286-300, affected diabetogenic CD4(+) T cells in nonobese diabetic (NOD) mice. When administered i.p., CTB-2.5 mi activated 2.5 mi(+) T cells and following intragastric delivery generated Ag-specific Foxp3(+) Treg and Th2 cells. While 2.5 mi(+) and GAD-specific T cells were tolerized in diabetes-resistant NODxB6.Foxp3(EGFP) F1 and nonobese resistant (NOR) mice, this did not occur in NOD mice. This indicated that NOD mice had a recessive genetic resistance to induce oral tolerance to both CTB-fused epitopes. In contrast to NODxB6.Foxp3(EGFP) F1 mice, oral treatment in NOD mice lead to strong 2.5 mi(+) T-cell activation and the sequestration of these cells to the effector-memory pool. Oral treatment of NOD mice with CTB-2.5 mi failed to prevent diabetes. These findings underline the importance of investigating the effect of oral vaccine formulations on diabetogenic T cells as in selected cases they may have counterproductive consequences in human patients. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Estimating the cost of cholera-vaccine delivery from the societal point of view: A case of introduction of cholera vaccine in Bangladesh.

    Science.gov (United States)

    Sarker, Abdur Razzaque; Islam, Ziaul; Khan, Iqbal Ansary; Saha, Amit; Chowdhury, Fahima; Khan, Ashraful Islam; Cravioto, Alejandro; Clemens, John David; Qadri, Firdausi; Khan, Jahangir A M

    2015-09-11

    Cholera is a major global public health problem that causes both epidemic and endemic disease. The World Health Organization recommends oral cholera vaccines as a public health tool in addition to traditional prevention practices and treatments in both epidemic and endemic settings. In many developing countries like Bangladesh, the major issue concerns the affordability of this vaccine. In February 2011, a feasibility study entitled, "Introduction of Cholera Vaccine in Bangladesh (ICVB)", was conducted for a vaccination campaign using inactivated whole-cell cholera vaccine (Shanchol) in a high risk area of Mirpur, Dhaka. Empirical data obtained from this trial was used to determine the vaccination cost for a fully immunized person from the societal perspective. A total of 123,661 people were fully vaccinated receiving two doses of the vaccine, while 18,178 people received one dose of the same vaccine. The total cost for vaccine delivery was US$ 492,238 giving a total vaccination cost per fully-vaccinated individual of US$ 3.98. The purchase cost of the vaccine accounted for 58% of the overall cost of vaccination. Attempts to reduce the per-dose cost of the vaccine are likely to have a large impact on the cost of similar vaccination campaigns in the future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Long-term effect of oral immunization against influenza with a gamma-inactivated vaccine in mice

    International Nuclear Information System (INIS)

    Noack, K.; Tischner, H.; Pohl, W.D.; Braeuniger, S.; Nordheim, W.

    1986-01-01

    NMRI mice were immunized orally twice within 10 days with an influenza vaccine inactivated by gamma radiation. The immunization with a relatively low dosis led to the occurence of low specific antibody titer in the lung lavage fluid up to 6th month. Despite of the low titer, immunized mice were protected against aerogenic infection for about 6 months. Protection was demonstrated in comparison to non-immunized mice by a limited increase of cells in bronchoalveolar lavage, low virus titer in the lung and survival of most animals after a lethal aerosol challenge with the live virus. (author)

  17. The cholera

    International Nuclear Information System (INIS)

    Castaneda, Elizabeth; De la Hoz, Fernando

    1996-01-01

    The cholera is a sharp intestinal infection, characterized by the abrupt appearance of abundant watery diarrhea and vomit, severe dehydration, metabolic imbalance and circulatory collapse; although it can study a symptomatic or to cause light symptomatology. In the cases serious non-treaties the death can take place in the 24 later hours to its appearance; the lethality in these cases can exceed 50 percent. However. With the treatment of re-hydration appropriate. This decreases to less ten percent. The cholera is related in direct form with the poverty; it is presented where accumulation and lack of measures of hygiene exist and of drinkable water. It is for it that the best strategy to prevent the illness is to eliminate the factors that favor its transmission: to improve the quality of the water and to implement elementary measures of hygiene. When the environmental conditions are favorable, the cholera has been absent

  18. Clinical trial to evaluate safety and immunogenicity of an oral inactivated enterotoxigenic Escherichia coli prototype vaccine containing CFA/I overexpressing bacteria and recombinantly produced LTB/CTB hybrid protein.

    Science.gov (United States)

    Lundgren, A; Leach, S; Tobias, J; Carlin, N; Gustafsson, B; Jertborn, M; Bourgeois, L; Walker, R; Holmgren, J; Svennerholm, A-M

    2013-02-06

    We have developed a new oral vaccine against enterotoxigenic Escherichia coli (ETEC) diarrhea containing killed recombinant E. coli bacteria expressing increased levels of ETEC colonization factors (CFs) and a recombinant protein (LCTBA), i.e. a hybrid between the binding subunits of E. coli heat labile toxin (LTB) and cholera toxin (CTB). We describe a randomized, comparator controlled, double-blind phase I trial in 60 adult Swedish volunteers of a prototype of this vaccine. The safety and immunogenicity of the prototype vaccine, containing LCTBA and an E. coli strain overexpressing the colonization factor CFA/I, was compared to a previously developed oral ETEC vaccine, consisting of CTB and inactivated wild type ETEC bacteria expressing CFA/I (reference vaccine). Groups of volunteers were given two oral doses of either the prototype or the reference vaccine; the prototype vaccine was administered at the same or a fourfold higher dosage than the reference vaccine. The prototype vaccine was found to be safe and equally well-tolerated as the reference vaccine at either dosage tested. The prototype vaccine induced mucosal IgA (fecal secretory IgA and intestine-derived IgA antibody secreting cell) responses to both LTB and CFA/I, as well as serum IgA and IgG antibody responses to LTB. Immunization with LCTBA resulted in about twofold higher mucosal and systemic IgA responses against LTB than a comparable dose of CTB. The higher dose of the prototype vaccine induced significantly higher fecal and systemic IgA responses to LTB and fecal IgA responses to CFA/I than the reference vaccine. These results demonstrate that CF over-expression and inclusion of the LCTBA hybrid protein in an oral inactivated ETEC vaccine does not change the safety profile when compared to a previous generation of such a vaccine and that the prototype vaccine induces significant dose dependent mucosal immune responses against CFA/I and LTB. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Household and Individual Risk Factors for Cholera among Cholera Vaccine Recipients in Rural Haiti.

    Science.gov (United States)

    Matias, Wilfredo R; Teng, Jessica E; Hilaire, Isabelle J; Harris, Jason B; Franke, Molly F; Ivers, Louise C

    2017-08-01

    Oral cholera vaccination was used as part of cholera control in Haiti, but the vaccine does not provide complete protection. We conducted secondary data analyses of a vaccine effectiveness study in Haiti to evaluate risk factors for cholera among cholera vaccine recipients. Individuals vaccinated against cholera that presented with acute watery diarrhea and had a stool sample positive for Vibrio cholerae O1 were included as cases. Up to four vaccinated individuals who did not present for treatment of diarrhea were included as controls for each case, and matched by location of residence, enrollment time, and age. We evaluated sociodemographic characteristics and risk factors for cholera. Univariable and multivariable logistic regression were performed to identify risk factors for cholera among vaccinees. Thirty-three vaccine recipients with culture-confirmed cholera were included as cases. One-hundred-and-seventeen of their matched controls reported receiving vaccine and were included as controls. In a multivariable analysis, self-reporting use of branded household water disinfection products as a means of treating water (adjusted relative risk [aRR] = 44.3, 95% confidence interval [CI] = 4.19-468.05, P = 0.002), and reporting having a latrine as the main household toilet (aRR = 4.22, 95% CI = 1.23-14.43, P = 0.02), were independent risk factors for cholera. Self-reporting always treating water (aRR = 0.09, 95% CI = 0.01-0.57, P = 0.01) was associated with protection against cholera. The field effectiveness of water, sanitation, and hygiene interventions used in combination with cholera vaccination in cholera control should be measured and monitored over time to identify and remediate shortcomings, and ensure successful impact on disease control.

  20. Avian cholera

    Science.gov (United States)

    Friend, Milton

    1999-01-01

    Avian cholera is a contagious disease resulting from infection by the bacterium Pasteurella multocida. Several subspecies of bacteria have been proposed for P. multocida, and at least 16 different P. multocida serotypes or characteristics of antigens in bacterial cells that differentiate bacterial variants from each other have been recognized. The serotypes are further differentiated by other methods, including DNA fingerprinting. These evaluations are useful for studying the ecology of avian cholera (Fig. 7.1), because different serotypes are generally found in poultry and free-ranging migratory birds. These evaluations also show that different P. multocida serotypes are found in wild birds in the eastern United States than those that are found in the birds in the rest of the Nation (Fig. 7.2).

  1. Oral Vaccination with Heat-Inactivated Mycobacterium bovis Does Not Interfere with the Antemortem Diagnostic Techniques for Tuberculosis in Goats

    Directory of Open Access Journals (Sweden)

    Alvaro Roy

    2017-08-01

    Full Text Available Vaccination against tuberculosis (TB is prohibited in cattle or other species subjected to specific TB eradication campaigns, due to the interference that it may cause with the official diagnostic tests. However, immunization with a heat-inactivated (HI Mycobacterium bovis vaccine via the oral route has been suggested to overcome this issue. In this study, the main goal was to assess the interference of the HI vaccine by different routes of administration using a previous vaccination and re-vaccination (boosting protocol. TB-free kid goats were divided into three groups: oral (n = 16, intramuscular (IM; n = 16, and control (n = 16. Results showed that there was a significant difference in the percentage of animals positive to the single intradermal test (SIT and blood based interferon-gamma release assay (IGRA caused by vaccination when performed in the IM group compared to the oral group (p < 0.001. Nevertheless, no positivity to the SIT or IGRA test was observed in orally vaccinated goats regardless of the different interpretation criteria applied. None of the groups presented positive antibody titers using an in-house ELISA and samples collected 2 months after the boost. These results suggest the potential usefulness of the HI vaccine by the oral route in goats to minimize the interference on diagnostic tests (skin and IGRA tests and reducing the necessity of defined antigens to replace the traditional purified protein derivatives for diagnosis. Finally, the results pave the way to future efficacy studies in goats using different routes of HI vaccination.

  2. Expression of cholera toxin B-proinsulin fusion protein in lettuce and tobacco chloroplasts--oral administration protects against development of insulitis in non-obese diabetic mice.

    Science.gov (United States)

    Ruhlman, Tracey; Ahangari, Raheleh; Devine, Andrew; Samsam, Mohtahsem; Daniell, Henry

    2007-07-01

    Lettuce and tobacco chloroplast transgenic lines expressing the cholera toxin B subunit-human proinsulin (CTB-Pins) fusion protein were generated. CTB-Pins accumulated up to ~16% of total soluble protein (TSP) in tobacco and up to ~2.5% of TSP in lettuce. Eight milligrams of powdered tobacco leaf material expressing CTB-Pins or, as negative controls, CTB-green fluorescent protein (CTB-GFP) or interferon-GFP (IFN-GFP), or untransformed leaf, were administered orally, each week for 7 weeks, to 5-week-old female non-obese diabetic (NOD) mice. The pancreas of CTB-Pins-treated mice showed decreased infiltration of cells characteristic of lymphocytes (insulitis); insulin-producing beta-cells in the pancreatic islets of CTB-Pins-treated mice were significantly preserved, with lower blood or urine glucose levels, by contrast with the few beta-cells remaining in the pancreatic islets of the negative controls. Increased expression of immunosuppressive cytokines, such as interleukin-4 and interleukin-10 (IL-4 and IL-10), was observed in the pancreas of CTB-Pins-treated NOD mice. Serum levels of immunoglobulin G1 (IgG1), but not IgG2a, were elevated in CTB-Pins-treated mice. Taken together, T-helper 2 (Th2) lymphocyte-mediated oral tolerance is a likely mechanism for the prevention of pancreatic insulitis and the preservation of insulin-producing beta-cells. This is the first report of expression of a therapeutic protein in transgenic chloroplasts of an edible crop. Transplastomic lettuce plants expressing CTB-Pins grew normally and transgenes were maternally inherited in T(1) progeny. This opens up the possibility for the low-cost production and delivery of human therapeutic proteins, and a strategy for the treatment of various other autoimmune diseases.

  3. Expression of cholera toxin B–proinsulin fusion protein in lettuce and tobacco chloroplasts – oral administration protects against development of insulitis in non-obese diabetic mice

    Science.gov (United States)

    Ruhlman, Tracey; Ahangari, Raheleh; Devine, Andrew; Samsam, Mohtahsem; Daniell, Henry

    2008-01-01

    Summary Lettuce and tobacco chloroplast transgenic lines expressing the cholera toxin B subunit–human proinsulin (CTB-Pins) fusion protein were generated. CTB-Pins accumulated up to ~16% of total soluble protein (TSP) in tobacco and up to ~2.5% of TSP in lettuce. Eight milligrams of powdered tobacco leaf material expressing CTB-Pins or, as negative controls, CTB–green fluorescent protein (CTB-GFP) or interferon–GFP (IFN-GFP), or untransformed leaf, were administered orally, each week for 7 weeks, to 5-week-old female non-obese diabetic (NOD) mice. The pancreas of CTB-Pins-treated mice showed decreased infiltration of cells characteristic of lymphocytes (insulitis); insulin-producing β-cells in the pancreatic islets of CTB-Pins-treated mice were significantly preserved, with lower blood or urine glucose levels, by contrast with the few β-cells remaining in the pancreatic islets of the negative controls. Increased expression of immunosuppressive cytokines, such as interleukin-4 and interleukin-10 (IL-4 and IL-10), was observed in the pancreas of CTB-Pins-treated NOD mice. Serum levels of immunoglobulin G1 (IgG1), but not IgG2a, were elevated in CTB-Pins-treated mice. Taken together, T-helper 2 (Th2) lymphocyte-mediated oral tolerance is a likely mechanism for the prevention of pancreatic insulitis and the preservation of insulin-producing β-cells. This is the first report of expression of a therapeutic protein in transgenic chloroplasts of an edible crop. Transplastomic lettuce plants expressing CTB-Pins grew normally and transgenes were maternally inherited in T1 progeny. This opens up the possibility for the low-cost production and delivery of human therapeutic proteins, and a strategy for the treatment of various other autoimmune diseases. PMID:17490448

  4. The Impact of a One-Dose versus Two-Dose Oral Cholera Vaccine Regimen in Outbreak Settings: A Modeling Study.

    Directory of Open Access Journals (Sweden)

    Andrew S Azman

    2015-08-01

    Full Text Available In 2013, a stockpile of oral cholera vaccine (OCV was created for use in outbreak response, but vaccine availability remains severely limited. Innovative strategies are needed to maximize the health impact and minimize the logistical barriers to using available vaccine. Here we ask under what conditions the use of one dose rather than the internationally licensed two-dose protocol may do both.Using mathematical models we determined the minimum relative single-dose efficacy (MRSE at which single-dose reactive campaigns are expected to be as or more effective than two-dose campaigns with the same amount of vaccine. Average one- and two-dose OCV effectiveness was estimated from published literature and compared to the MRSE. Results were applied to recent outbreaks in Haiti, Zimbabwe, and Guinea using stochastic simulations to illustrate the potential impact of one- and two-dose campaigns. At the start of an epidemic, a single dose must be 35%-56% as efficacious as two doses to avert the same number of cases with a fixed amount of vaccine (i.e., MRSE between 35% and 56%. This threshold decreases as vaccination is delayed. Short-term OCV effectiveness is estimated to be 77% (95% CI 57%-88% for two doses and 44% (95% CI -27% to 76% for one dose. This results in a one-dose relative efficacy estimate of 57% (interquartile range 13%-88%, which is above conservative MRSE estimates. Using our best estimates of one- and two-dose efficacy, we projected that a single-dose reactive campaign could have prevented 70,584 (95% prediction interval [PI] 55,943-86,205 cases in Zimbabwe, 78,317 (95% PI 57,435-100,150 in Port-au-Prince, Haiti, and 2,826 (95% PI 2,490-3,170 cases in Conakry, Guinea: 1.1 to 1.2 times as many as a two-dose campaign. While extensive sensitivity analyses were performed, our projections of cases averted in past epidemics are based on severely limited single-dose efficacy data and may not fully capture uncertainty due to imperfect

  5. Occurrence of specific influenza antibodies in saliva and nasal secretion of monkeys (Macacus rhesus) after oral administration of influenza vaccine inactivated by gamma rays

    International Nuclear Information System (INIS)

    Tischner, H.; Huyuh, P.L.; Phan, P.N.; Bergmann, K.C.; Hoang, T.N.; Luther, P.; Nordheim, W.; Braeuniger, S.; Waldman, R.H.

    1984-01-01

    Antibodies in nasal secretion and saliva were measured in 10 Macacus rhesus wich had been immunized orally with a 60 Co-gamma-inactivated influenza vaccine. Prior to immunization monkeys had no detectable antibodies against hemagglutinin (HA) and neuraminidase, resp. in sera or secretions. Oral immunization using intraoesophageal tubing, induced the occurrence of both antiobodies in pilocarpine-stimulated secretions within 28 days but not in sera. 6 monkeys reacted with increasing HA antibodies in nasal secretions and 10 monkeys with increasing neuraminidase antibodies. Salivary HA antibodies occurred in 8 of 10 and neuraminidase antibodies in 9 of 10 animals. In most cases antibodies occurred in both secretions simultaneously. These results demonstrate the stimulation of antibodies specific to influenza in the respiratory tract of monkeys after oral immunization with an inactivated vaccine, for the first time. (author)

  6. Potential impact of reactive vaccination in controlling cholera ...

    African Journals Online (AJOL)

    Background. To contain ongoing cholera outbreaks, the World Health Organization has suggested that reactive vaccination should be considered in addition to its previous control measures. Objectives. To explore the potential impact of a hypothetical reactive oral cholera vaccination using the example of the recent ...

  7. Cholera: an overview with reference to the Yemen epidemic.

    Science.gov (United States)

    Rabaan, Ali A

    2018-06-22

    Cholera is a secretory diarrhoeal disease caused by infection with Vibrio cholerae, primarily the V. cholerae O1 El Tor biotype. There are approximately 2.9 million cases in 69 endemic countries annually, resulting in 95 000 deaths. Cholera is associated with poor infrastructure and lack of access to sanitation and clean drinking water. The current cholera epidemic in Yemen, linked to spread of V. cholerae O1 (Ogawa serotype), is associated with the ongoing war. This has devastated infrastructure and health services. The World Health Organization had estimated that 172 286 suspected cases arose between 27th April and 19th June 2017, including 1170 deaths. While there are three oral cholera vaccines prequalified by the World Health Organization, there are issues surrounding vaccination campaigns in conflict situations, exacerbated by external factors such as a global vaccine shortage. Major movements of people complicates surveillance and administration of double doses of vaccines. Cholera therapy mainly depends on rehydration, with use of antibiotics in more severe infections. Concerns have arisen about the rise of antibiotic resistance in cholera, due to mobile genetic elements. In this review, we give an overview of cholera epidemiology, virulence, antibiotic resistance, therapy and vaccines, in the light of the ongoing epidemic in Yemen.

  8. Cholera Illness and Symptoms

    Science.gov (United States)

    ... Share Compartir Cholera is an acute, diarrheal illness caused by infection of the intestine with the bacterium Vibrio cholerae and is spread by ingestion of contaminated food or water. The infection is often mild or without symptoms, ...

  9. Cholera Prevention and Control

    Science.gov (United States)

    ... name=”commit” type=”submit” value=”Submit” /> Prevention & Control Recommend on Facebook Tweet Share Compartir Prevention of ... of cholera and other diarrheal disease prevention. Prevention & Control Topics Ending Cholera: The Global Roadmap to 2030 ...

  10. Introduction of sequential inactivated polio vaccine-oral polio vaccine schedule for routine infant immunization in Brazil's National Immunization Program.

    Science.gov (United States)

    Domingues, Carla Magda Allan S; de Fátima Pereira, Sirlene; Cunha Marreiros, Ana Carolina; Menezes, Nair; Flannery, Brendan

    2014-11-01

    In August 2012, the Brazilian Ministry of Health introduced inactivated polio vaccine (IPV) as part of sequential polio vaccination schedule for all infants beginning their primary vaccination series. The revised childhood immunization schedule included 2 doses of IPV at 2 and 4 months of age followed by 2 doses of oral polio vaccine (OPV) at 6 and 15 months of age. One annual national polio immunization day was maintained to provide OPV to all children aged 6 to 59 months. The decision to introduce IPV was based on preventing rare cases of vaccine-associated paralytic polio, financially sustaining IPV introduction, ensuring equitable access to IPV, and preparing for future OPV cessation following global eradication. Introducing IPV during a national multivaccination campaign led to rapid uptake, despite challenges with local vaccine supply due to high wastage rates. Continuous monitoring is required to achieve high coverage with the sequential polio vaccine schedule. Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

  11. Switch from oral to inactivated poliovirus vaccine in Yogyakarta Province, Indonesia: summary of coverage, immunity, and environmental surveillance.

    Science.gov (United States)

    Wahjuhono, Gendro; Revolusiana; Widhiastuti, Dyah; Sundoro, Julitasari; Mardani, Tri; Ratih, Woro Umi; Sutomo, Retno; Safitri, Ida; Sampurno, Ondri Dwi; Rana, Bardan; Roivainen, Merja; Kahn, Anna-Lea; Mach, Ondrej; Pallansch, Mark A; Sutter, Roland W

    2014-11-01

    Inactivated poliovirus vaccine (IPV) is rarely used in tropical developing countries. To generate additional scientific information, especially on the possible emergence of vaccine-derived polioviruses (VDPVs) in an IPV-only environment, we initiated an IPV introduction project in Yogyakarta, an Indonesian province. In this report, we present the coverage, immunity, and VDPV surveillance results. In Yogyakarta, we established environmental surveillance starting in 2004; and conducted routine immunization coverage and seroprevalence surveys before and after a September 2007 switch from oral poliovirus vaccine (OPV) to IPV, using standard coverage and serosurvey methods. Rates and types of polioviruses found in sewage samples were analyzed, and all poliovirus isolates after the switch were sequenced. Vaccination coverage (>95%) and immunity (approximately 100%) did not change substantially before and after the IPV switch. No VDPVs were detected. Before the switch, 58% of environmental samples contained Sabin poliovirus; starting 6 weeks after the switch, Sabin polioviruses were rarely isolated, and if they were, genetic sequencing suggested recent introductions. This project demonstrated that under almost ideal conditions (good hygiene, maintenance of universally high IPV coverage, and corresponding high immunity against polioviruses), no emergence and circulation of VDPV could be detected in a tropical developing country setting. © The Author 2014. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  12. The Impact of a One-Dose versus Two-Dose Oral Cholera Vaccine Regimen in Outbreak Settings: A Modeling Study

    Science.gov (United States)

    Azman, Andrew S.; Luquero, Francisco J.; Ciglenecki, Iza; Grais, Rebecca F.; Sack, David A.; Lessler, Justin

    2015-01-01

    Background In 2013, a stockpile of oral cholera vaccine (OCV) was created for use in outbreak response, but vaccine availability remains severely limited. Innovative strategies are needed to maximize the health impact and minimize the logistical barriers to using available vaccine. Here we ask under what conditions the use of one dose rather than the internationally licensed two-dose protocol may do both. Methods and Findings Using mathematical models we determined the minimum relative single-dose efficacy (MRSE) at which single-dose reactive campaigns are expected to be as or more effective than two-dose campaigns with the same amount of vaccine. Average one- and two-dose OCV effectiveness was estimated from published literature and compared to the MRSE. Results were applied to recent outbreaks in Haiti, Zimbabwe, and Guinea using stochastic simulations to illustrate the potential impact of one- and two-dose campaigns. At the start of an epidemic, a single dose must be 35%–56% as efficacious as two doses to avert the same number of cases with a fixed amount of vaccine (i.e., MRSE between 35% and 56%). This threshold decreases as vaccination is delayed. Short-term OCV effectiveness is estimated to be 77% (95% CI 57%–88%) for two doses and 44% (95% CI −27% to 76%) for one dose. This results in a one-dose relative efficacy estimate of 57% (interquartile range 13%–88%), which is above conservative MRSE estimates. Using our best estimates of one- and two-dose efficacy, we projected that a single-dose reactive campaign could have prevented 70,584 (95% prediction interval [PI] 55,943–86,205) cases in Zimbabwe, 78,317 (95% PI 57,435–100,150) in Port-au-Prince, Haiti, and 2,826 (95% PI 2,490–3,170) cases in Conakry, Guinea: 1.1 to 1.2 times as many as a two-dose campaign. While extensive sensitivity analyses were performed, our projections of cases averted in past epidemics are based on severely limited single-dose efficacy data and may not fully capture

  13. Cholera in Zimbabwe

    NARCIS (Netherlands)

    Pruyt, E.

    2009-01-01

    By the end of December 2008, alarming reports and articles concerning the cholera outbreak in Zimbabwe received plenty of international media coverage. By that time nearly 30000 cases of cholera infections and 1600 cholera deaths had been reported. In the first week of January 2009, a System

  14. Epidemiology of the 2016 Cholera Outbreak of Chibombo District ...

    African Journals Online (AJOL)

    the 11 water samples available 2 (18%) were found to have faeces ... awareness of cholera transmission whenever the country ... It's transmitted by the faeco-oral route. Although most ... There was limited spread of disease among clusters of.

  15. Antimicrobial drugs for treating cholera

    Science.gov (United States)

    Leibovici-Weissman, Ya'ara; Neuberger, Ami; Bitterman, Roni; Sinclair, David; Salam, Mohammed Abdus; Paul, Mical

    2014-01-01

    Background Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. Objectives To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. Search methods We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Selection criteria Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Data collection and analysis Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Main results Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43

  16. Using Mobile Health (mHealth) and geospatial mapping technology in a mass campaign for reactive oral cholera vaccination in rural Haiti.

    Science.gov (United States)

    Teng, Jessica E; Thomson, Dana R; Lascher, Jonathan S; Raymond, Max; Ivers, Louise C

    2014-01-01

    In mass vaccination campaigns, large volumes of data must be managed efficiently and accurately. In a reactive oral cholera vaccination (OCV) campaign in rural Haiti during an ongoing epidemic, we used a mobile health (mHealth) system to manage data on 50,000 participants in two isolated communities. Data were collected using 7-inch tablets. Teams pre-registered and distributed vaccine cards with unique barcodes to vaccine-eligible residents during a census in February 2012. First stored on devices, data were uploaded nightly via Wi-fi to a web-hosted database. During the vaccination campaign between April and June 2012, residents presented their cards at vaccination posts and their barcodes were scanned. Vaccinee data from the census were pre-loaded on tablets to autopopulate the electronic form. Nightly analysis of the day's community coverage informed the following day's vaccination strategy. We generated case-finding reports allowing us to identify those who had not yet been vaccinated. During 40 days of vaccination, we collected approximately 1.9 million pieces of data. A total of 45,417 people received at least one OCV dose; of those, 90.8% were documented to have received 2 doses. Though mHealth required up-front financial investment and training, it reduced the need for paper registries and manual data entry, which would have been costly, time-consuming, and is known to increase error. Using Global Positioning System coordinates, we mapped vaccine posts, population size, and vaccine coverage to understand the reach of the campaign. The hardware and software were usable by high school-educated staff. The use of mHealth technology in an OCV campaign in rural Haiti allowed timely creation of an electronic registry with population-level census data, and a targeted vaccination strategy in a dispersed rural population receiving a two-dose vaccine regimen. The use of mHealth should be strongly considered in mass vaccination campaigns in future initiatives.

  17. Combined use of inactivated and oral poliovirus vaccines in refugee camps and surrounding communities - Kenya, December 2013.

    Science.gov (United States)

    Sheikh, Mohamed A; Makokha, Frederick; Hussein, Abdullahi M; Mohamed, Gedi; Mach, Ondrej; Humayun, Kabir; Okiror, Samuel; Abrar, Leila; Nasibov, Orkhan; Burton, John; Unshur, Ahmed; Wannemuehler, Kathleen; Estivariz, Concepcion F

    2014-03-21

    Since the launch of the Global Polio Eradication Initiative (GPEI) in 1988, circulation of indigenous wild poliovirus (WPV) has continued without interruption in only three countries: Afghanistan, Nigeria, and Pakistan. During April-December 2013, a polio outbreak caused by WPV type 1 (WPV1) of Nigerian origin resulted in 217 cases in or near the Horn of Africa, including 194 cases in Somalia, 14 cases in Kenya, and nine cases in Ethiopia (all cases were reported as of March 10, 2014). During December 14-18, 2013, Kenya conducted the first-ever campaign providing inactivated poliovirus vaccine (IPV) together with oral poliovirus vaccine (OPV) as part of its outbreak response. The campaign targeted 126,000 children aged ≤59 months who resided in Somali refugee camps and surrounding communities near the Kenya-Somalia border, where most WPV1 cases had been reported, with the aim of increasing population immunity levels to ensure interruption of any residual WPV transmission and prevent spread from potential new importations. A campaign evaluation and vaccination coverage survey demonstrated that combined administration of IPV and OPV in a mass campaign is feasible and can achieve coverage >90%, although combined IPV and OPV campaigns come at a higher cost than OPV-only campaigns and require particular attention to vaccinator training and supervision. Future operational studies could assess the impact on population immunity and the cost-effectiveness of combined IPV and OPV campaigns to accelerate interruption of poliovirus transmission during polio outbreaks and in certain areas in which WPV circulation is endemic.

  18. Development and preclinical evaluation of safety and immunogenicity of an oral ETEC vaccine containing inactivated E. coli bacteria overexpressing colonization factors CFA/I, CS3, CS5 and CS6 combined with a hybrid LT/CT B subunit antigen, administered alone and together with dmLT adjuvant.

    Science.gov (United States)

    Holmgren, J; Bourgeois, L; Carlin, N; Clements, J; Gustafsson, B; Lundgren, A; Nygren, E; Tobias, J; Walker, R; Svennerholm, A-M

    2013-05-07

    A first-generation oral inactivated whole-cell enterotoxigenic Escherichia coli (ETEC) vaccine, comprising formalin-killed ETEC bacteria expressing different colonization factor (CF) antigens combined with cholera toxin B subunit (CTB), when tested in phase III studies did not significantly reduce overall (generally mild) ETEC diarrhea in travelers or children although it reduced more severe ETEC diarrhea in travelers by almost 80%. We have now developed a novel more immunogenic ETEC vaccine based on recombinant non-toxigenic E. coli strains engineered to express increased amounts of CF antigens, including CS6 as well as an ETEC-based B subunit protein (LCTBA), and the optional combination with a nontoxic double-mutant heat-labile toxin (LT) molecule (dmLT) as an adjuvant. Two test vaccines were prepared under GMP: (1) A prototype E. coli CFA/I-only formalin-killed whole-cell+LCTBA vaccine, and (2) A "complete" inactivated multivalent ETEC-CF (CFA/I, CS3, CS5 and CS6 antigens) whole-cell+LCTBA vaccine. These vaccines, when given intragastrically alone or together with dmLT in mice, were well tolerated and induced strong intestinal-mucosal IgA antibody responses as well as serum IgG and IgA responses to each of the vaccine CF antigens as well as to LT B subunit (LTB). Both mucosal and serum responses were further enhanced (adjuvanted) when the vaccines were co-administered with dmLT. We conclude that the new multivalent oral ETEC vaccine, both alone and especially in combination with the dmLT adjuvant, shows great promise for further testing in humans. Copyright © 2013 Elsevier Ltd. All rights reserved.

  19. Low-dose oral tolerance due to antigen in the diet suppresses differentially the cholera toxin-adjuvantized IgE, IgA and IgG response

    DEFF Research Database (Denmark)

    Christensen, Hanne Risager; Kjær, Tanja; Frøkiær, Hanne

    2003-01-01

    Background: Cholera toxin (CT) is used as a mucosal adjuvant amongst other applications for studying food allergy because oral administration of antigen with CT induces an antigen-specific type 2 response, including IgE and IgA production. Priorly established oral tolerance due to antigen...... soy-trypsin inhibitor (KSTI) (F0 mice) and mice fed a soy-free diet (F2 mice) were orally immunized with KSTI and CT. KSTI-specific serum IgG1, IgG2a, IgA and IgE and fecal IgA were monitored. KSTI-stimulated cell proliferation and interleukin (IL)-6 production were determined. Results: The anti...... immunizations. However, cell proliferation and IL-6 production were clearly suppressed even after five immunizations. Conclusions: Priorly established low-dose oral tolerance considerably suppressed the CT-adjuvantized KSTI-specific IgE, IgA and cellular immune response but only weakly and transiently the Ig...

  20. A single dose of live-attenuated 638 Vibrio cholerae oral vaccine is safe and immunogenic in adult volunteers in Mozambique

    Directory of Open Access Journals (Sweden)

    Hilda María García

    2011-12-01

    Full Text Available A placebo-controlled randomized, double-blind, clinical trial was carried out to assess the safety, reactogenicity, and immunogenicity of the lyophilized vaccine candidate against cholera derived from the live attenuated 638 Vibrio cholerae O1 El Tor Ogawa strain. One hundred and twenty presumably healthy female and male adult volunteers aged between 18 and 50 years were included. They were from Maputo, Mozambique a cholera endemic area, where, in addition, human immunodeficiency virus (HIV seroprevalence is from 20 to 30%. A dose of 2 x 10 9 colony forming units (CFU was given to 80 subjects and other 40 received only vaccine lyoprotectors as a placebo control. Out-patient follow-up of adverse events was carried out during the following 30 days after vaccination. The immune response was evaluated by the estimation of seroconversion rate and the geometric mean titer (GMT of vibriocidal antibodies in the sera from volunteers that was collected previously, and at days 14 and 21 after immunization. No serious adverse events were reported. The adverse events found in the vaccine group were similar to those of the placebo groups. They were independent from the detection of antibodies against HIV-1, HIV-2, hepatitis (H A; HC and hepatitis B surface antigen. The presence of helminthes did not modify the incidence of adverse events. The 638 vaccine strain was isolated in 37 (46.25% vaccinated volunteer's feces. The peak of the GMT of vibriocidal antibodies in the vaccine group was 9056 versus 39 in the placebo group at 14 days with a total seroconversion of 97.4% at 21 days. The 638 vaccine candidate is safe and immunogenic in a cholera endemic region.

  1. Multi-site cholera surveillance within the African Cholera Surveillance Network shows endemicity in Mozambique, 2011–2015

    Science.gov (United States)

    Langa, José Paulo; Dengo Baloi, Liliana; Wood, Richard; Ouedraogo, Issaka; Njanpop-Lafourcade, Berthe-Marie; Inguane, Dorteia; Elias Chitio, Jucunu; Mhlanga, Themba; Gujral, Lorna; D. Gessner, Bradford; Munier, Aline; A. Mengel, Martin

    2017-01-01

    Background Mozambique suffers recurrent annual cholera outbreaks especially during the rainy season between October to March. The African Cholera Surveillance Network (Africhol) was implemented in Mozambique in 2011 to generate accurate detailed surveillance data to support appropriate interventions for cholera control and prevention in the country. Methodology/Principal findings Africhol was implemented in enhanced surveillance zones located in the provinces of Sofala (Beira), Zambézia (District Mocuba), and Cabo Delgado (Pemba City). Data were also analyzed from the three outbreak areas that experienced the greatest number of cases during the time period under observation (in the districts of Cuamba, Montepuez, and Nampula). Rectal swabs were collected from suspected cases for identification of Vibrio cholerae, as well as clinical, behavioral, and socio-demographic variables. We analyzed factors associated with confirmed, hospitalized, and fatal cholera using multivariate logistic regression models. A total of 1,863 suspected cases and 23 deaths (case fatality ratio (CFR), 1.2%) were reported from October 2011 to December 2015. Among these suspected cases, 52.2% were tested of which 23.5% were positive for Vibrio cholerae O1 Ogawa. Risk factors independently associated with the occurrence of confirmed cholera were living in Nampula city district, the year 2014, human immunodeficiency virus infection, and the primary water source for drinking. Conclusions/Significance Cholera was endemic in Mozambique during the study period with a high CFR and identifiable risk factors. The study reinforces the importance of continued cholera surveillance, including a strong laboratory component. The results enhanced our understanding of the need to target priority areas and at-risk populations for interventions including oral cholera vaccine (OCV) use, and assess the impact of prevention and control strategies. Our data were instrumental in informing integrated prevention and

  2. Multi-site cholera surveillance within the African Cholera Surveillance Network shows endemicity in Mozambique, 2011-2015.

    Science.gov (United States)

    Semá Baltazar, Cynthia; Langa, José Paulo; Dengo Baloi, Liliana; Wood, Richard; Ouedraogo, Issaka; Njanpop-Lafourcade, Berthe-Marie; Inguane, Dorteia; Elias Chitio, Jucunu; Mhlanga, Themba; Gujral, Lorna; D Gessner, Bradford; Munier, Aline; A Mengel, Martin

    2017-10-01

    Mozambique suffers recurrent annual cholera outbreaks especially during the rainy season between October to March. The African Cholera Surveillance Network (Africhol) was implemented in Mozambique in 2011 to generate accurate detailed surveillance data to support appropriate interventions for cholera control and prevention in the country. Africhol was implemented in enhanced surveillance zones located in the provinces of Sofala (Beira), Zambézia (District Mocuba), and Cabo Delgado (Pemba City). Data were also analyzed from the three outbreak areas that experienced the greatest number of cases during the time period under observation (in the districts of Cuamba, Montepuez, and Nampula). Rectal swabs were collected from suspected cases for identification of Vibrio cholerae, as well as clinical, behavioral, and socio-demographic variables. We analyzed factors associated with confirmed, hospitalized, and fatal cholera using multivariate logistic regression models. A total of 1,863 suspected cases and 23 deaths (case fatality ratio (CFR), 1.2%) were reported from October 2011 to December 2015. Among these suspected cases, 52.2% were tested of which 23.5% were positive for Vibrio cholerae O1 Ogawa. Risk factors independently associated with the occurrence of confirmed cholera were living in Nampula city district, the year 2014, human immunodeficiency virus infection, and the primary water source for drinking. Cholera was endemic in Mozambique during the study period with a high CFR and identifiable risk factors. The study reinforces the importance of continued cholera surveillance, including a strong laboratory component. The results enhanced our understanding of the need to target priority areas and at-risk populations for interventions including oral cholera vaccine (OCV) use, and assess the impact of prevention and control strategies. Our data were instrumental in informing integrated prevention and control efforts during major cholera outbreaks in recent years.

  3. [The cholera epidemic in Latin America].

    Science.gov (United States)

    Olsvik, O

    1992-05-30

    An outbreak of cholera started in Peru in January 1991 and spread through most Latin American countries within a year. This was the first known epidemic of cholera in America for more than a century. In 1991, 321,334 persons were reported to have cholera in Peru, 119,063 were hospitalized, and 2,906 died. Other countries like Ecuador, Colombia, Guatemala, Brazil, Mexico, Bolivia, Chile, El Salvador, Venezuela and Honduras were also affected, but these countries combined accounted for only 20% of the cases registered in Peru. In April 1992, all Latin American countries except Uruguay, Paraguay and French Guyana have reported cholera. The mortality rate for the epidemic in Latin America was only 1%, mainly owing to good oral rehydration treatment provided by Local health services and the Pan American Health Organization. The causative organism was Vibrio cholerae, serogroup O1, serotype Inaba (and Ogawa) of the El Tor biotype. Genetic characterization shows this strain to be unique, and the designation is reserved for the Latin American strain, distinguishing it from the other El Tor isolates from the 7th pandemic.

  4. Cholera Fact Sheet

    Science.gov (United States)

    ... news-room/fact-sheets/detail/cholera","@context":"http://schema.org","@type":"Article"}; العربية 中文 français русский español ... that includes feedback at the local level and information-sharing at the global level. Cholera cases are ...

  5. What is cholera?

    DEFF Research Database (Denmark)

    Tamason, Charlotte Crim; Tulsiani, Suhella; Siddique, A.

    2016-01-01

    more commonly described than death (47%) as negative effects of cholera. Conclusions: The results from this study are suggestive of a need for reformulation of cholera and diarrhea communication. Messaging should be based on signs of dehydration, foregoing the use of medical terminology....

  6. Viral Aetiology of Acute Flaccid Paralysis Surveillance Cases, before and after Vaccine Policy Change from Oral Polio Vaccine to Inactivated Polio Vaccine

    Directory of Open Access Journals (Sweden)

    T. S. Saraswathy Subramaniam

    2014-01-01

    Full Text Available Since 1992, surveillance for acute flaccid paralysis (AFP cases was introduced in Malaysia along with the establishment of the National Poliovirus Laboratory at the Institute for Medical Research. In 2008, the Ministry of Health, Malaysia, approved a vaccine policy change from oral polio vaccine to inactivated polio vaccine (IPV. Eight states started using IPV in the Expanded Immunization Programme, followed by the remaining states in January 2010. The objective of this study was to determine the viral aetiology of AFP cases below 15 years of age, before and after vaccine policy change from oral polio vaccine to inactivated polio vaccine. One hundred and seventy-nine enteroviruses were isolated from the 3394 stool specimens investigated between 1992 and December 2012. Fifty-six out of 107 virus isolates were polioviruses and the remaining were non-polio enteroviruses. Since 2009 after the sequential introduction of IPV in the childhood immunization programme, no Sabin polioviruses were isolated from AFP cases. In 2012, the laboratory AFP surveillance was supplemented with environmental surveillance with sewage sampling. Thirteen Sabin polioviruses were also isolated from sewage in the same year, but no vaccine-derived poliovirus was detected during this period.

  7. Radiolabelling of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Santos, R.G.; Neves, Nicoli M.J. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN), Belo Horizonte, MG (Brazil); Abdalla, L.F.; Brandao, R.L.; Etchehebehere, L. [Ouro Preto Univ., MG (Brazil). Escola de Farmacia. Lab. de Fisiologia e Bioquimica de Microorganismos; Lima, M.E. de [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Bioquimica e Imunologia; Nicoli, J.R. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Inst. de Ciencias Biologicas. Dept. de Microbiologia

    1999-11-01

    Binding of cholera toxin to ganglioside receptors of enterocyte microvilli catalyzes the activation of adenylate cyclase causing a rise in cAMP which final result is a copious diarrhea. Saccharomyces boulardii, a nonpathogenic yeast has been used to prevent diarrhea. Although the antidiarrheic properties of S. boulardii are widely recognized, this yeast has been used on empirical basis, and the mechanism of this protective effect is unknown. The addition of cholera toxin to S. boulardii induces the raising of cAMP that triggers the activation of neutral trehalase. This suggests that toxin specifically binding to cells, is internalized and active the protein phosphorylation cascade. Our objective is labeling the cholera toxin to verify the presence of binding sites on yeast cell surfaces for the cholera toxin. Cholera toxin was radiolabelled with Na {sup 125} I by a chloramine-T method modified from Cuatrecasas and Griffiths et alii. The {sup 125} I-Cholera toxin showed a specific radioactivity at about 1000 cpm/fmol toxin. Biological activity of labeled cholera toxin measured by trehalase activation was similar to the native toxin. (author) 5 refs., 3 figs.; e-mail: nevesmj at urano.cdtn.br

  8. Cholera - management and prevention.

    Science.gov (United States)

    Davies, Hannah G; Bowman, Conor; Luby, Stephen P

    2017-06-01

    Cholera is an acute secretory diarrhoeal infection caused by the bacterium Vibrio cholerae. It is likely to have originated in the Indian sub-continent; however, it spread to cause six worldwide pandemics between 1817-1923. The ongoing seventh worldwide pandemic of cholera began in 1961. The intensity, duration and severity of cholera epidemics have been increasing, signaling the need for more effective control and prevention measures. The response to the cholera pandemics of the 19th century led to the development of safe and effective sanitation and water systems which have effectively removed the risk of cholera in many settings. However, such systems are not in place to protect billions of people worldwide. Although some progress has been made in expanding access to water in recent years, achieving optimal infrastructure will, in the most optimistic scenario, take decades. Climate change, extreme weather events and rapid urbanisation suggests that alternatives to the current paradigm of providing large centralised water and sanitation systems should be considered, including smaller decentralised systems. The aim of this review paper is to provide an overview of current knowledge regarding management of cholera with a focus on prevention measures including vaccination and water and sanitation interventions. © 2017 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  9. Radiolabelling of cholera toxin

    International Nuclear Information System (INIS)

    Santos, R.G.; Neves, Nicoli M.J.; Abdalla, L.F.; Brandao, R.L.; Etchehebehere, L.; Lima, M.E. de; Nicoli, J.R.

    1999-01-01

    Binding of cholera toxin to ganglioside receptors of enterocyte microvilli catalyzes the activation of adenylate cyclase causing a rise in cAMP which final result is a copious diarrhea. Saccharomyces boulardii, a nonpathogenic yeast has been used to prevent diarrhea. Although the antidiarrheic properties of S. boulardii are widely recognized, this yeast has been used on empirical basis, and the mechanism of this protective effect is unknown. The addition of cholera toxin to S. boulardii induces the raising of cAMP that triggers the activation of neutral trehalase. This suggests that toxin specifically binding to cells, is internalized and active the protein phosphorylation cascade. Our objective is labeling the cholera toxin to verify the presence of binding sites on yeast cell surfaces for the cholera toxin. Cholera toxin was radiolabelled with Na 125 I by a chloramine-T method modified from Cuatrecasas and Griffiths et alii. The 125 I-Cholera toxin showed a specific radioactivity at about 1000 cpm/fmol toxin. Biological activity of labeled cholera toxin measured by trehalase activation was similar to the native toxin. (author)

  10. Cholera in pregnancy: Clinical and immunological aspects.

    Science.gov (United States)

    Khan, Ashraful I; Chowdhury, Fahima; Leung, Daniel T; Larocque, Regina C; Harris, Jason B; Ryan, Edward T; Calderwood, Stephen B; Qadri, Firdausi

    2015-10-01

    The objective of this study was to examine the clinical and immunological features of cholera in pregnancy. Women of reproductive age presenting to the icddr,b Dhaka hospital with cholera, and enrolled as part of a larger cohort study, were tested for pregnancy on admission. We compared initial clinical features and immune responses of pregnant patients with non-pregnant female patients at days 2, 7 and 21 after infection. Among reproductive age women enrolled between January 2001 and May 2006, 9.7% (14/144) were pregnant. The duration of diarrhoea prior to admission tended to be higher in pregnant compared to non-pregnant patients (p=0.08), but other clinical characteristics did not differ. Antibody responses to cholera toxin B subunit (CtxB), toxin-coregulated pilus A (TcpA), Vibrio cholerae lipopolysaccharide (LPS), and serum vibriocidal antibody responses, were comparable between pregnant and non-pregnant patients. There were no deaths among the pregnant cases or non-pregnant controls, and no adverse foetal outcomes, including stillbirths, during 21 days of follow up of pregnant cases. To our knowledge, this is the first report of immune responses in pregnant women with cholera. We found that pregnant woman early in pregnancy has comparable clinical illness and subsequent immune responses compared to non-pregnant women. These findings suggest that the evaluation of safety and immunogenicity of oral cholera vaccines in pregnancy should be an area of future investigations. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Cholera in travelers: shifting tides in epidemiology, management, and prevention.

    Science.gov (United States)

    Fillion, Katie; Mileno, Maria D

    2015-01-01

    The distribution of cholera's devastating effects has changed. While cholera is endemic in 50 countries mostly in Asia and Africa, more than half of the cases reported in 2012 were in the Western Hemisphere, predominantly Haiti. Since the current epidemic began in Haiti in 2010, there has been spread to the Dominican Republic, Cuba, and most recently Mexico. Several recent case reports document individuals returning home from affected areas with diarrhea from cholera, in some cases severe. Hopeful news reported the containment of an outbreak through the use of a Vibrio cholera vaccine. There are safe and effective oral cholera vaccines available and recommended in outbreaks and endemic areas, although they are not currently available in the USA or to travelers. This review aims to discuss the latest data to aid our current recommendations for the prevention of cholera in travelers beyond standard personal and food hygiene precautions for the prevention of travelers' diarrhea and to offer insights on the most current data available about cholera vaccine progress and potential use.

  12. What is Cholera?

    Indian Academy of Sciences (India)

    Cholera is a rapidly dehydrating watery diarrheal disease that can lead to death in less than 24 hours if untreated, making it, according to WHO, “one of the most rapidly fatal infectious illnesses known” ...

  13. Cholera in Azov area

    Directory of Open Access Journals (Sweden)

    O. N. Domashenko

    2015-01-01

    Full Text Available The purpose of research is analysis of clinical course and treatment results of patients with cholera in the Azov area. Materials and methods. During the period from 29.05.2011 to 19.08.2011 33 cases of cholera (32 adults and 1 child and 25 vibrio carriers (22 adults and 3 children, which were caused by toxigenic strains of Vibrio cholera El Tor serogroup O1 Ogawa. Results. Likely factors of disease transmission in Mariupol are sea and river water, and the fish that were caught in the waters of the city. Typical and watery diarrhoea, vomiting, abdominal pain and lack of normal body temperature, dehydration syndrome, characterized clinical cholera for adults in most cases. The mean duration of diarrhoea was 6,6 days. At 46.9% observed atypical symptoms in 10 (31,3% – abdominal pain (1 patient cramping in 7 cases, localized in the epigastria region, at 2-over stomach. In 5 patients (15,6% had an increase in body temperature to 37,2–37,7 degrees Celsius. In 15 (46,9% patients had severe nausea accompanied by vomiting. Easy for cholera was observed in 1 (3.1%, moderate – in 14 (43,8%, heavy – in 17 (53,1% patients. Dehydration I level is set at 4 (12,5%, II – from 6 (18,7%, III – in 18 (56,3%, IV – 4 (12,5% patients. Cholera outbreak was characterized by a predominance of severe disease and severe dehydration (III and IV, which was observed in 68.8% of patients. The decisive factor in the treatment of cholera patients was initiated in a timely manner rehydration therapy, in particular the introduction of the solution «Trisol». Against the background of rehydration therapy hyperkalaemia was observed in 9,4% of cases, vascular rehydration at 9,4%, the cell rehydration in 3,1% of patients. Fatal accidents cholera outbreaks have not been observed. Conclusion. Clinical diagnosis of cholera and the provision of medical care in the prehospital phase were poor, indicating the need for systematic conducting training seminars among experts

  14. Introduction of Sequential Inactivated Polio Vaccine–Oral Polio Vaccine Schedule for Routine Infant Immunization in Brazil’s National Immunization Program

    Science.gov (United States)

    Domingues, Carla Magda Allan S.; de Fátima Pereira, Sirlene; Marreiros, Ana Carolina Cunha; Menezes, Nair; Flannery, Brendan

    2015-01-01

    In August 2012, the Brazilian Ministry of Health introduced inactivated polio vaccine (IPV) as part of sequential polio vaccination schedule for all infants beginning their primary vaccination series. The revised childhood immunization schedule included 2 doses of IPV at 2 and 4 months of age followed by 2 doses of oral polio vaccine (OPV) at 6 and 15 months of age. One annual national polio immunization day was maintained to provide OPV to all children aged 6 to 59 months. The decision to introduce IPV was based on preventing rare cases of vaccine-associated paralytic polio, financially sustaining IPV introduction, ensuring equitable access to IPV, and preparing for future OPV cessation following global eradication. Introducing IPV during a national multivaccination campaign led to rapid uptake, despite challenges with local vaccine supply due to high wastage rates. Continuous monitoring is required to achieve high coverage with the sequential polio vaccine schedule. PMID:25316829

  15. [Cholera in pediatrics].

    Science.gov (United States)

    Lezama-Basulto, L A; Mota-Hernández, F

    1993-09-01

    Cholerae is a grave and acute bacterial intestine infection which is caused by a bacilo, V. cholerae 01, that produces toxic products. Its clinical symptoms range from abundant liquid diarrhoea combined with vomiting and rapid dehydration. It is highly lethal when right treatment is not applied. There are also cases of cholera where victims do not show any symptoms of it, that is asymptomatic carriers. Any clinical suspicion of cholerae has to be corroborated by epidemiological data and its diagnostic confirmation should be done by isolating the bacteria, V. cholerae. When beginning the treatment, it is not necessary to confirm the diagnostic and this is based on the restitution of the liquids lost through vomiting and facing using any methods that are recommended for any other type of diarrhoea. The antimicrobial treatment is used only for grave cases. This present revision includes recent knowledge about cholerae emphasising on the effective management of cases through an adequate use of right treatment methods and also using the principal prevention measures against dissemination of this disease.

  16. Cholera Toxin B: One Subunit with Many Pharmaceutical Applications

    Directory of Open Access Journals (Sweden)

    Keegan J. Baldauf

    2015-03-01

    Full Text Available Cholera, a waterborne acute diarrheal disease caused by Vibrio cholerae, remains prevalent in underdeveloped countries and is a serious health threat to those living in unsanitary conditions. The major virulence factor is cholera toxin (CT, which consists of two subunits: the A subunit (CTA and the B subunit (CTB. CTB is a 55 kD homopentameric, non-toxic protein binding to the GM1 ganglioside on mammalian cells with high affinity. Currently, recombinantly produced CTB is used as a component of an internationally licensed oral cholera vaccine, as the protein induces potent humoral immunity that can neutralize CT in the gut. Additionally, recent studies have revealed that CTB administration leads to the induction of anti-inflammatory mechanisms in vivo. This review will cover the potential of CTB as an immunomodulatory and anti-inflammatory agent. We will also summarize various recombinant expression systems available for recombinant CTB bioproduction.

  17. Chitin-induced T6SS in Vibrio cholerae is dependent on ChiS activation.

    Science.gov (United States)

    Chourashi, Rhishita; Das, Suman; Dhar, Debarpan; Okamoto, Keinosuke; Mukhopadhyay, Asish K; Chatterjee, Nabendu Sekhar

    2018-05-01

    Vibrio cholerae regularly colonizes the chitinous exoskeleton of crustacean shells in the aquatic region. The type 6 secretion system (T6SS) in V. cholerae is an interbacterial killing device. This system is thought to provide a competitive advantage to V. cholerae in a polymicrobial community of the aquatic region under nutrient-poor conditions. V. cholerae chitin sensing is known to be initiated by the activation of a two-component sensor histidine kinase ChiS in the presence of GlcNAc2 (N,N'-diacetylchitobiose) residues generated by the action of chitinases on chitin. It is known that T6SS in V. cholerae is generally induced by chitin. However, the effect of ChiS activation on T6SS is unknown. Here, we found that ChiS inactivation resulted in impaired bacterial killing and reduced expression of T6SS genes. Active ChiS positively affected T6SS-mediated natural transformation in V. cholerae. ChiS depletion or inactivation also resulted in reduced colonization on insoluble chitin surfaces. Therefore, we have shown that V. cholerae colonization on chitinous surfaces activates ChiS, which promotes T6SS-dependent bacterial killing and horizontal gene transfer. We also highlight the importance of chitinases in T6SS upregulation.

  18. Inactivation of the Fanconi anemia/BRCA pathway in lung and oral cancers: implications for treatment and survival.

    Science.gov (United States)

    Marsit, Carmen J; Liu, Mei; Nelson, Heather H; Posner, Marshall; Suzuki, Makoto; Kelsey, Karl T

    2004-01-29

    Inactivation of the FANC-BRCA pathway via promoter methylation of the FANCF gene renders cells sensitive to DNA crosslinking agents, and has been identified in ovarian cancer cell lines and sporadic primary tumor tissues. We investigated epigenetic alterations in the FANC-BRCA pathway in head and neck squamous cell carcinomas (HNSCC) and non-small-cell lung cancers (NSCLC) using methylation-specific PCR. Promoter methylation of FANCF occurred in 15% (13/89) of HNSCCs and 14% (22/158) of NSCLCs. Methylation of BRCA1 occurred only in 6/158 NSCLC, and was limited to adenocarcinomas and large-cell carcinomas of the lung. No methylation of BRCA2 was detected. FANCF methylation was associated with a shorter duration of tobacco use (P=0.03) and a younger age of starting smoking (P=0.06) in NSCLC, and with a greater number of years of alcohol drinking (P=0.02) in HNSCC. In adenocarcinomas of the lung, FANCF promoter methylation was a significant predictor of poor survival with a hazard ratio of 3.1 (95% CI 1.2-7.9). This study demonstrates that inactivation of the FANC-BRCA pathway is relatively common in solid tumors and may be related to tobacco and alcohol exposure and survival of these patients.

  19. Antimicrobial drugs for treating cholera.

    Science.gov (United States)

    Leibovici-Weissman, Ya'ara; Neuberger, Ami; Bitterman, Roni; Sinclair, David; Salam, Mohammed Abdus; Paul, Mical

    2014-06-19

    Cholera is an acute watery diarrhoea caused by infection with the bacterium Vibrio cholerae, which if severe can cause rapid dehydration and death. Effective management requires early diagnosis and rehydration using oral rehydration salts or intravenous fluids. In this review, we evaluate the additional benefits of treating cholera with antimicrobial drugs. To quantify the benefit of antimicrobial treatment for patients with cholera, and determine whether there are differences between classes of antimicrobials or dosing schedules. We searched the Cochrane Infectious Disease Group Specialized Register; the Cochrane Central Register of Controlled Trials (CENTRAL); PubMed; EMBASE; African Index Medicus; LILACS; Science Citation Index; metaRegister of Controlled Trials; WHO International Clinical Trials Registry Platform; conference proceedings; and reference lists to March 2014. Randomized and quasi-randomized controlled clinical trials in adults and children with cholera that compared: 1) any antimicrobial treatment with placebo or no treatment; 2) different antimicrobials head-to-head; or 3) different dosing schedules or different durations of treatment with the same antimicrobial. Two reviewers independently applied inclusion and exclusion criteria, and extracted data from included trials. Diarrhoea duration and stool volume were defined as primary outcomes. We calculated mean difference (MD) or ratio of means (ROM) for continuous outcomes, with 95% confidence intervals (CI), and pooled data using a random-effects meta-analysis. The quality of evidence was assessed using the GRADE approach. Thirty-nine trials were included in this review with 4623 participants. Antimicrobials versus placebo or no treatment Overall, antimicrobial therapy shortened the mean duration of diarrhoea by about a day and a half compared to placebo or no treatment (MD -36.77 hours, 95% CI -43.51 to -30.03, 19 trials, 1013 participants, moderate quality evidence). Antimicrobial therapy also

  20. Inactivation of Vibrio cholerae O1 El Tor inoculated into Peruvian ''choro'' mussels (Aulacomya ater) and two species of clams (Argopecten purpuratus and Gari solida) using medium-dose irradiation

    International Nuclear Information System (INIS)

    Torres, Z.; Bernuy, B.; Kahn, G.; Zapata, G.; Vivanco, M.; Guzman, E.; Leon, R.

    2001-01-01

    The radiation decimal reduction dose (D 10 ) for Vibrio cholerae O1 biotype El Tor inoculated through the natural feeding system into three species of bivalve mollusks from the Peruvian Pacific coast: ''choro'' mussels (Aulacome ater), ''abanico'' clams (Argopecten purpuratus), and common clams (Gari solida), was determined in vivo. The D 10 value obtained in vivo was 0.14 kGy in all mollusks tested. Concurrent studies conducted to determine the potential use of irradiation to extend the microbiological shelf-life of the mollusks during post-irradiation storage at 0-1 deg. C indicated that a dose of 1.0 kGy was optimal for choro mussels and abanico clams, whereas 2.0 kGy produced the best results when treating common clams. Shelf-life extension thus achieved was 31 days for choro mussels, 16 days for abanico clams, and 21 days for common clams. Non-irradiated control samples of all mollusks spoiled after 17 days of refrigerated storage. There were no significant (p<.05) adverse effects from the application of the optimal radiation treatments on the sensory characteristics (i.e. appearance, odor, flavor, and texture) of the mollusks. Total volatile basic nitrogen (VBN) and pH values were examined for use as indexes of seafood freshness. (author)

  1. The global burden of cholera

    Science.gov (United States)

    Lopez, Anna Lena; You, Young Ae; Kim, Young Eun; Sah, Binod; Maskery, Brian; Clemens, John

    2012-01-01

    Abstract Objective To estimate the global burden of cholera using population-based incidence data and reports. Methods Countries with a recent history of cholera were classified as endemic or non-endemic, depending on whether they had reported cholera cases in at least three of the five most recent years. The percentages of the population in each country that lacked access to improved sanitation were used to compute the populations at risk for cholera, and incidence rates from published studies were applied to groups of countries to estimate the annual number of cholera cases in endemic countries. The estimates of cholera cases in non-endemic countries were based on the average numbers of cases reported from 2000 to 2008. Literature-based estimates of cholera case-fatality rates (CFRs) were used to compute the variance-weighted average cholera CFRs for estimating the number of cholera deaths. Findings About 1.4 billion people are at risk for cholera in endemic countries. An estimated 2.8 million cholera cases occur annually in such countries (uncertainty range: 1.4–4.3) and an estimated 87 000 cholera cases occur in non-endemic countries. The incidence is estimated to be greatest in children less than 5 years of age. Every year about 91 000 people (uncertainty range: 28 000 to 142 000) die of cholera in endemic countries and 2500 people die of the disease in non-endemic countries. Conclusion The global burden of cholera, as determined through a systematic review with clearly stated assumptions, is high. The findings of this study provide a contemporary basis for planning public health interventions to control cholera. PMID:22461716

  2. Introduction of Inactivated Polio Vaccine, Withdrawal of Type 2 Oral Polio Vaccine, and Routine Immunization Strengthening in the Eastern Mediterranean Region.

    Science.gov (United States)

    Fahmy, Kamal; Hampton, Lee M; Langar, Houda; Patel, Manish; Mir, Tahir; Soloman, Chandrasegarar; Hasman, Andreas; Yusuf, Nasir; Teleb, Nadia

    2017-07-01

    The Global Polio Eradication Initiative has reduced the global incidence of polio by 99% and the number of countries with endemic polio from 125 to 3 countries. The Polio Eradication and Endgame Strategic Plan 2013-2018 (Endgame Plan) was developed to end polio disease. Key elements of the endgame plan include strengthening immunization systems using polio assets, introducing inactivated polio vaccine (IPV), and replacing trivalent oral polio vaccine with bivalent oral polio vaccine ("the switch"). Although coverage in the Eastern Mediterranean Region (EMR) with the third dose of a vaccine containing diphtheria, tetanus, and pertussis antigens (DTP3) was ≥90% in 14 countries in 2015, DTP3 coverage in EMR dropped from 86% in 2010 to 80% in 2015 due to civil disorder in multiple countries. To strengthen their immunization systems, Pakistan, Afghanistan, and Somalia developed draft plans to integrate Polio Eradication Initiative assets, staff, structure, and activities with their Expanded Programmes on Immunization, particularly in high-risk districts and regions. Between 2014 and 2016, 11 EMR countries introduced IPV in their routine immunization program, including all of the countries at highest risk for polio transmission (Afghanistan, Pakistan, Somalia, and Yemen). As a result, by the end of 2016 all EMR countries were using IPV except Egypt, where introduction of IPV was delayed by a global shortage. The switch was successfully implemented in EMR due to the motivation, engagement, and cooperation of immunization staff and decision makers across all national levels. Moreover, the switch succeeded because of the ability of even the immunization systems operating under hardship conditions of conflict to absorb the switch activities. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  3. The Duration of Intestinal Immunity After an Inactivated Poliovirus Vaccine Booster Dose in Children Immunized With Oral Vaccine: A Randomized Controlled Trial.

    Science.gov (United States)

    John, Jacob; Giri, Sidhartha; Karthikeyan, Arun S; Lata, Dipti; Jeyapaul, Shalini; Rajan, Anand K; Kumar, Nirmal; Dhanapal, Pavithra; Venkatesan, Jayalakshmi; Mani, Mohanraj; Hanusha, Janardhanan; Raman, Uma; Moses, Prabhakar D; Abraham, Asha; Bahl, Sunil; Bandyopadhyay, Ananda S; Ahmad, Mohammad; Grassly, Nicholas C; Kang, Gagandeep

    2017-02-15

    In 2014, 2 studies showed that inactivated poliovirus vaccine (IPV) boosts intestinal immunity in children previously immunized with oral poliovirus vaccine (OPV). As a result, IPV was introduced in mass campaigns to help achieve polio eradication. We conducted an open-label, randomized, controlled trial to assess the duration of the boost in intestinal immunity following a dose of IPV given to OPV-immunized children. Nine hundred healthy children in Vellore, India, aged 1-4 years were randomized (1:1:1) to receive IPV at 5 months (arm A), at enrollment (arm B), or no vaccine (arm C). The primary outcome was poliovirus shedding in stool 7 days after bivalent OPV challenge at 11 months. For children in arms A, B, and C, 284 (94.7%), 297 (99.0%), and 296 (98.7%), respectively, were eligible for primary per-protocol analysis. Poliovirus shedding 7 days after challenge was less prevalent in arms A and B compared with C (24.6%, 25.6%, and 36.4%, respectively; risk ratio 0.68 [95% confidence interval: 0.53-0.87] for A versus C, and 0.70 [0.55-0.90] for B versus C). Protection against poliovirus remained elevated 6 and 11 months after an IPV boost, although at a lower level than reported at 1 month. CTRI/2014/09/004979. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America.

  4. Integrative genomic and functional analysis of human oral squamous cell carcinoma cell lines reveals synergistic effects of FAT1 and CASP8 inactivation.

    Science.gov (United States)

    Hayes, Tyler F; Benaich, Nathan; Goldie, Stephen J; Sipilä, Kalle; Ames-Draycott, Ashley; Cai, Wenjun; Yin, Guangliang; Watt, Fiona M

    2016-12-01

    Oral squamous cell carcinoma (OSCC) is genetically highly heterogeneous, which contributes to the challenges of treatment. To create an in vitro model that accurately reflects this heterogeneity, we generated a panel of HPV-negative OSCC cell lines. By whole exome sequencing of the lines and matched patient blood samples, we demonstrate that the mutational spectrum of the lines is representative of primary OSCC in The Cancer Genome Atlas. We show that loss of function mutations in FAT1 (an atypical cadherin) and CASP8 (Caspase 8) frequently occur in the same tumour. OSCC cells with inactivating FAT1 mutations exhibited reduced intercellular adhesion. Knockdown of FAT1 and CASP8 individually or in combination in OSCC cells led to increased cell migration and clonal growth, resistance to Staurosporine-induced apoptosis and, in some cases, increased terminal differentiation. The OSCC lines thus represent a valuable resource for elucidating the impact of different mutations on tumour behaviour. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  5. Comparing sociocultural features of cholera in three endemic African settings

    Science.gov (United States)

    2013-01-01

    Background Cholera mainly affects developing countries where safe water supply and sanitation infrastructure are often rudimentary. Sub-Saharan Africa is a cholera hotspot. Effective cholera control requires not only a professional assessment, but also consideration of community-based priorities. The present work compares local sociocultural features of endemic cholera in urban and rural sites from three field studies in southeastern Democratic Republic of Congo (SE-DRC), western Kenya and Zanzibar. Methods A vignette-based semistructured interview was used in 2008 in Zanzibar to study sociocultural features of cholera-related illness among 356 men and women from urban and rural communities. Similar cross-sectional surveys were performed in western Kenya (n = 379) and in SE-DRC (n = 360) in 2010. Systematic comparison across all settings considered the following domains: illness identification; perceived seriousness, potential fatality and past household episodes; illness-related experience; meaning; knowledge of prevention; help-seeking behavior; and perceived vulnerability. Results Cholera is well known in all three settings and is understood to have a significant impact on people’s lives. Its social impact was mainly characterized by financial concerns. Problems with unsafe water, sanitation and dirty environments were the most common perceived causes across settings; nonetheless, non-biomedical explanations were widespread in rural areas of SE-DRC and Zanzibar. Safe food and water and vaccines were prioritized for prevention in SE-DRC. Safe water was prioritized in western Kenya along with sanitation and health education. The latter two were also prioritized in Zanzibar. Use of oral rehydration solutions and rehydration was a top priority everywhere; healthcare facilities were universally reported as a primary source of help. Respondents in SE-DRC and Zanzibar reported cholera as affecting almost everybody without differentiating much for gender, age

  6. Cholera Epidemic - Lusaka, Zambia, October 2017-May 2018.

    Science.gov (United States)

    Sinyange, Nyambe; Brunkard, Joan M; Kapata, Nathan; Mazaba, Mazyanga Lucy; Musonda, Kunda G; Hamoonga, Raymond; Kapina, Muzala; Kapaya, Fred; Mutale, Lwito; Kateule, Ernest; Nanzaluka, Francis; Zulu, James; Musyani, Chileshe Lukwesa; Winstead, Alison V; Davis, William W; N'cho, Hammad S; Mulambya, Nelia L; Sakubita, Patrick; Chewe, Orbie; Nyimbili, Sulani; Onwuekwe, Ezinne V C; Adrien, Nedghie; Blackstock, Anna J; Brown, Travis W; Derado, Gordana; Garrett, Nancy; Kim, Sunkyung; Hubbard, Sydney; Kahler, Amy M; Malambo, Warren; Mintz, Eric; Murphy, Jennifer; Narra, Rupa; Rao, Gouthami G; Riggs, Margaret A; Weber, Nicole; Yard, Ellen; Zyambo, Khozya D; Bakyaita, Nathan; Monze, Namani; Malama, Kennedy; Mulwanda, Jabbin; Mukonka, Victor M

    2018-05-18

    On October 6, 2017, an outbreak of cholera was declared in Zambia after laboratory confirmation of Vibrio cholerae O1, biotype El Tor, serotype Ogawa, from stool specimens from two patients with acute watery diarrhea. The two patients had gone to a clinic in Lusaka, the capital city, on October 4. Cholera cases increased rapidly, from several hundred cases in early December 2017 to approximately 2,000 by early January 2018 (Figure). In collaboration with partners, the Zambia Ministry of Health (MoH) launched a multifaceted public health response that included increased chlorination of the Lusaka municipal water supply, provision of emergency water supplies, water quality monitoring and testing, enhanced surveillance, epidemiologic investigations, a cholera vaccination campaign, aggressive case management and health care worker training, and laboratory testing of clinical samples. In late December 2017, a number of water-related preventive actions were initiated, including increasing chlorine levels throughout the city's water distribution system and placing emergency tanks of chlorinated water in the most affected neighborhoods; cholera cases declined sharply in January 2018. During January 10-February 14, 2018, approximately 2 million doses of oral cholera vaccine were administered to Lusaka residents aged ≥1 year. However, in mid-March, heavy flooding and widespread water shortages occurred, leading to a resurgence of cholera. As of May 12, 2018, the outbreak had affected seven of the 10 provinces in Zambia, with 5,905 suspected cases and a case fatality rate (CFR) of 1.9%. Among the suspected cases, 5,414 (91.7%), including 98 deaths (CFR = 1.8%), occurred in Lusaka residents.

  7. [Cholera in children. A report of 8 cases].

    Science.gov (United States)

    Lezama-Basulto, L A; Mota-Hernández, F; Bravo-Barrios, E

    1993-11-01

    Cholera is an acute intestinal infection caused by Vibrio cholerae 01. When an infected person presents severe dehydration and is not adequately treated, he or she will develop hypovolemic shock and eventually could died. There is scarce information concerning this disease in the Pediatric group. Herein we report on eight cases of Pediatric cholera, in children 17 month to four years of age. Seven patients out of eight were admitted presenting dehydration. Four presenting mild or moderate dehydration and three presenting hypovolemic shock. These three patients were rehydrated by intravenous route and thereafter the hydration was maintained by oral therapy. The outcome was uneventful in six patients. One patient developed abdominal distention probably due to hypopotassemia, and another patient presented hyponatremia and seizures. All the patients recovered within five days after admission.

  8. Cholera cases cluster in time and space in Matlab, Bangladesh: implications for targeted preventive interventions.

    Science.gov (United States)

    Debes, Amanda K; Ali, Mohammad; Azman, Andrew S; Yunus, Mohammad; Sack, David A

    2016-12-01

    : Cholera remains a serious public health threat in Asia, Africa and in parts of the Americas. Three World health Organization (WHO) pre-qualified oral cholera vaccines are now available but their supply is limited, so current supplies must be administered strategically. This requires an improved understanding of disease transmission and control strategies. : We used demographics and disease surveillance data collected from 1991 to 2000 in Matlab, Bangladesh, to estimate the spatial and temporal extent of the zone of increased risk around cholera cases. Specifically, we compare the cholera incidence among individuals living close to cholera cases with that among individuals living close to those without medically-attended cholera in this rural endemic setting. : Those living within 50 m of a confirmed cholera case had 36 times (95% confidence interval: 23-56) the risk of becoming a cholera case in the first 3 days (after case presentation) compared with risk elsewhere in the community. The relative risk gradually declined in space and time, but remained significantly high up to 450 me away within 3 days of case presentation, and up to 150 m away within 23 days from the date of presentation of the case. : These findings suggest that, if conducted rapidly, vaccinating individuals living close to a case (ring vaccination) could be an efficient and effective strategy to target vaccine to a high-risk population in an endemic setting. © The Author 2016; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association

  9. Case studies in cholera: lessons in medical history and science.

    Science.gov (United States)

    Kavic, S. M.; Frehm, E. J.; Segal, A. S.

    1999-01-01

    Cholera, a prototypical secretory diarrheal disease, is an ancient scourge that has both wrought great suffering and taught many valuable lessons, from basic sanitation to molecular signal transduction. Victims experience the voluminous loss of bicarbonate-rich isotonic saline at a rate that may lead to hypovolemic shock, metabolic acidosis, and death within afew hours. Intravenous solution therapy as we know it was first developed in an attempt to provide life-saving volume replacement for cholera patients. Breakthroughs in epithelial membrane transport physiology, such as the discovery of sugar and salt cotransport, have paved the way for oral replacement therapy in areas of the world where intravenous replacement is not readily available. In addition, the discovery of the cholera toxin has yielded vital information about toxigenic infectious diseases, providing a framework in which to study fundamental elements of intracellular signal transduction pathways, such as G-proteins. Cholera may even shed light on the evolution and pathophysiology of cystic fibrosis, the most commonly inherited disease among Caucasians. The goal of this paper is to review, using case studies, some of the lessons learned from cholera throughout the ages, acknowledging those pioneers whose seminal work led to our understanding of many basic concepts in medical epidemiology, microbiology, physiology, and therapeutics. PMID:11138935

  10. Spatial and environmental connectivity analysis in a cholera vaccine trial.

    Science.gov (United States)

    Emch, Michael; Ali, Mohammad; Root, Elisabeth D; Yunus, Mohammad

    2009-02-01

    This paper develops theory and methods for vaccine trials that utilize spatial and environmental information. Satellite imagery is used to identify whether households are connected to one another via water bodies in a study area in rural Bangladesh. Then relationships between neighborhood-level cholera vaccine coverage and placebo incidence and neighborhood-level spatial variables are measured. The study hypothesis is that unvaccinated people who are environmentally connected to people who have been vaccinated will be at lower risk compared to unvaccinated people who are environmentally connected to people who have not been vaccinated. We use four datasets including: a cholera vaccine trial database, a longitudinal demographic database of the rural population from which the vaccine trial participants were selected, a household-level geographic information system (GIS) database of the same study area, and high resolution Quickbird satellite imagery. An environmental connectivity metric was constructed by integrating the satellite imagery with the vaccine and demographic databases linked with GIS. The results show that there is a relationship between neighborhood rates of cholera vaccination and placebo incidence. Thus, people are indirectly protected when more people in their environmentally connected neighborhood are vaccinated. This result is similar to our previous work that used a simpler Euclidean distance neighborhood to measure neighborhood vaccine coverage [Ali, M., Emch, M., von Seidlein, L., Yunus, M., Sack, D. A., Holmgren, J., et al. (2005). Herd immunity conferred by killed oral cholera vaccines in Bangladesh. Lancet, 366(9479), 44-49]. Our new method of measuring environmental connectivity is more precise since it takes into account the transmission mode of cholera and therefore this study validates our assertion that the oral cholera vaccine provides indirect protection in addition to direct protection.

  11. Comparison of serum and salivary antibodies in children vaccinated with oral live or parenteral inactivated poliovirus vaccines of different antigen concentrations.

    Science.gov (United States)

    Zaman, S; Carlsson, B; Jalil, F; Mellander, L; Van Wezel, A L; Böttiger, M; Hanson, L A

    1991-12-01

    A new antigen-rich inactivated poliovirus vaccine (IPV) in ordinary (IPV1), double (IPV2) and quadruple (IPV4) antigen concentrations was given in 2 doses to 6 and 18 week old Pakistani infants. The immune responses to poliovirus types 1 and 3 were compared to those in infants given three doses of oral poliovirus vaccine (OPV) at 6, 12 and 18 weeks of age. Enzyme-linked immunosorbent assay, ELISA, was used to estimate IgG and IgA in serum and secretory IgA (SIgA) in saliva. Two to three years later, a follow-up of the serum antibody response was carried out in the same infants using a microneutralization test. Serum IgG antibody responses to poliovirus type 1 antigen after two doses of IPV1, IPV2 and IPV4 were not significantly higher than the response after three doses of OPV at 21 weeks of age (p greater than 0.05). The serum IgG responses to poliovirus type 3 were similar to those against type 1 in all the groups. Mean neutralizing antibody titres to poliovirus type 1 was significantly higher in the IPV2 group than the rest of the groups (p less than 0.01). For type 3, these titres were highest but not significantly, in the IPV4 group (p greater than 0.05). This study shows that two doses of a new antigen-rich IPV can give similar immediate serum antibody responses as OPV but higher late responses. SIgA antibodies in saliva were more efficiently induced by OPV after three doses than after 2 doses of IPV (p less than 0.05).

  12. Strategies to Prevent Cholera Introduction during International Personnel Deployments: A Computational Modeling Analysis Based on the 2010 Haiti Outbreak

    Science.gov (United States)

    Lewnard, Joseph A.; Antillón, Marina; Gonsalves, Gregg; Miller, Alice M.; Ko, Albert I.; Pitzer, Virginia E.

    2016-01-01

    Background Introduction of Vibrio cholerae to Haiti during the deployment of United Nations (UN) peacekeepers in 2010 resulted in one of the largest cholera epidemics of the modern era. Following the outbreak, a UN-commissioned independent panel recommended three pre-deployment intervention strategies to minimize the risk of cholera introduction in future peacekeeping operations: screening for V. cholerae carriage, administering prophylactic antimicrobial chemotherapies, or immunizing with oral cholera vaccines. However, uncertainty regarding the effectiveness of these approaches has forestalled their implementation by the UN. We assessed how the interventions would have impacted the likelihood of the Haiti cholera epidemic. Methods and Findings We developed a stochastic model for cholera importation and transmission, fitted to reported cases during the first weeks of the 2010 outbreak in Haiti. Using this model, we estimated that diagnostic screening reduces the probability of cases occurring by 82% (95% credible interval: 75%, 85%); however, false-positive test outcomes may hamper this approach. Antimicrobial chemoprophylaxis at time of departure and oral cholera vaccination reduce the probability of cases by 50% (41%, 57%) and by up to 61% (58%, 63%), respectively. Chemoprophylaxis beginning 1 wk before departure confers a 91% (78%, 96%) reduction independently, and up to a 98% reduction (94%, 99%) if coupled with vaccination. These results are not sensitive to assumptions about the background cholera incidence rate in the endemic troop-sending country. Further research is needed to (1) validate the sensitivity and specificity of rapid test approaches for detecting asymptomatic carriage, (2) compare prophylactic efficacy across antimicrobial regimens, and (3) quantify the impact of oral cholera vaccine on transmission from asymptomatic carriers. Conclusions Screening, chemoprophylaxis, and vaccination are all effective strategies to prevent cholera introduction

  13. Conjugated Linoleic Acid Reduces Cholera Toxin Production In Vitro and In Vivo by Inhibiting Vibrio cholerae ToxT Activity.

    Science.gov (United States)

    Withey, Jeffrey H; Nag, Drubhajyoti; Plecha, Sarah C; Sinha, Ritam; Koley, Hemanta

    2015-12-01

    The severe diarrheal disease cholera is endemic in over 50 countries. Current therapies for cholera patients involve oral and/or intravenous rehydration, often combined with the use of antibiotics to shorten the duration and intensity of the disease. However, as antibiotic resistance increases, treatment options will become limited. Linoleic acid has been shown to be a potent negative effector of V. cholerae virulence that acts on the major virulence transcription regulator protein, ToxT, to inhibit virulence gene expression. ToxT activates transcription of the two major virulence factors required for disease, cholera toxin (CT) and toxin-coregulated pilus (TCP). A conjugated form of linoleic acid (CLA) is currently sold over the counter as a dietary supplement and is generally recognized as safe by the U.S. Food and Drug Administration. This study examined whether CLA could be used as a new therapy to reduce CT production, which, in turn, would decrease disease duration and intensity in cholera patients. CLA could be used in place of traditional antibiotics and would be very unlikely to generate resistance, as it affects only virulence factor production and not bacterial growth or survival. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Environmental Monitoring of Endemic Cholera

    Science.gov (United States)

    ElNemr, W.; Jutla, A. S.; Constantin de Magny, G.; Hasan, N. A.; Islam, M.; Sack, R.; Huq, A.; Hashem, F.; Colwell, R.

    2012-12-01

    Cholera remains a major public health threat. Since Vibrio cholerae, the causative agent of the disease, is autochthonous to riverine, estuarine, and coastal waters, it is unlikely the bacteria can be eradicated from its natural habitat. Prediction of disease, in conjunction with preventive vaccination can reduce the prevalence rate of a disease. Understanding the influence of environmental parameters on growth and proliferation of bacteria is an essential first step in developing prediction methods for outbreaks. Large scale geophysical variables, such as SST and coastal chlorophyll, are often associated with conditions favoring growth of V. cholerae. However, local environmental factors, meaning biological activity in ponds from where the bulk of populations in endemic regions derive water for daily usage, are either neglected or oversimplified. Using data collected from several sites in two geographically distinct locations in South Asia, we have identified critical local environmental factors associated with cholera outbreak. Of 18 environmental variables monitored for water sources in Mathbaria (a coastal site near the Bay of Bengal) and Bakergonj (an inland site) of Bangladesh, water depth and chlorophyll were found to be important factors associated with initiation of cholera outbreaks. Cholera in coastal regions appears to be related to intrusion. However, monsoonal flooding creates conditions for cholera epidemics in inland regions. This may be one of the first attempts to relate in-situ environmental observations with cholera. We anticipate that it will be useful for further development of prediction models in the resource constrained regions.

  15. Epidemic cholera spreads like wildfire

    Science.gov (United States)

    Roy, Manojit; Zinck, Richard D.; Bouma, Menno J.; Pascual, Mercedes

    2014-01-01

    Cholera is on the rise globally, especially epidemic cholera which is characterized by intermittent and unpredictable outbreaks that punctuate periods of regional disease fade-out. These epidemic dynamics remain however poorly understood. Here we examine records for epidemic cholera over both contemporary and historical timelines, from Africa (1990-2006) and former British India (1882-1939). We find that the frequency distribution of outbreak size is fat-tailed, scaling approximately as a power-law. This pattern which shows strong parallels with wildfires is incompatible with existing cholera models developed for endemic regions, as it implies a fundamental role for stochastic transmission and local depletion of susceptible hosts. Application of a recently developed forest-fire model indicates that epidemic cholera dynamics are located above a critical phase transition and propagate in similar ways to aggressive wildfires. These findings have implications for the effectiveness of control measures and the mechanisms that ultimately limit the size of outbreaks.

  16. Environmental Factors Influencing Epidemic Cholera

    Science.gov (United States)

    Jutla, Antarpreet; Whitcombe, Elizabeth; Hasan, Nur; Haley, Bradd; Akanda, Ali; Huq, Anwar; Alam, Munir; Sack, R. Bradley; Colwell, Rita

    2013-01-01

    Cholera outbreak following the earthquake of 2010 in Haiti has reaffirmed that the disease is a major public health threat. Vibrio cholerae is autochthonous to aquatic environment, hence, it cannot be eradicated but hydroclimatology-based prediction and prevention is an achievable goal. Using data from the 1800s, we describe uniqueness in seasonality and mechanism of occurrence of cholera in the epidemic regions of Asia and Latin America. Epidemic regions are located near regional rivers and are characterized by sporadic outbreaks, which are likely to be initiated during episodes of prevailing warm air temperature with low river flows, creating favorable environmental conditions for growth of cholera bacteria. Heavy rainfall, through inundation or breakdown of sanitary infrastructure, accelerates interaction between contaminated water and human activities, resulting in an epidemic. This causal mechanism is markedly different from endemic cholera where tidal intrusion of seawater carrying bacteria from estuary to inland regions, results in outbreaks. PMID:23897993

  17. Development of stable Vibrio cholerae O1 Hikojima type vaccine strains co-expressing the Inaba and Ogawa lipopolysaccharide antigens.

    Directory of Open Access Journals (Sweden)

    Stefan L Karlsson

    Full Text Available We describe here the development of stable classical and El Tor V. cholerae O1 strains of the Hikojima serotype that co-express the Inaba and Ogawa antigens of O1 lipopolysaccharide (LPS. Mutation of the wbeT gene reduced LPS perosamine methylation and thereby gave only partial transformation into Ogawa LPS on the cell surface. The strains express approximately equal amounts of Inaba- and Ogawa-LPS antigens which are preserved after formalin-inactivation of the bacteria. Oral immunizations of both inbred and outbred mice with formalin-inactivated whole-cell vaccine preparations of these strains elicited strong intestinal IgA anti-LPS as well as serum vibriocidal antibody responses against both Inaba and Ogawa that were fully comparable to the responses induced by the licensed Dukoral vaccine. Passive protection studies in infant mice showed that immune sera raised against either of the novel Hikojima vaccine strains protected baby mice against infection with virulent strains of both serotypes. This study illustrates the power of using genetic manipulation to improve the properties of bacteria strains for use in killed whole-cell vaccines.

  18. Acalculous cholecystitis and septicemia caused by non-O1 Vibrio cholerae: first reported case and review of biliary infections with Vibrio cholerae.

    Science.gov (United States)

    West, B C; Silberman, R; Otterson, W N

    1998-03-01

    The first case of septicemic acute acalculous cholecystitis caused by non-O1 Vibrio cholerae is described in a healthy traveler, and biliary tract infections from V. cholerae are reviewed. Immediately after a vacation in Cancun, Mexico, a 55-year-old man developed acute cholecystitis. Blood and bile cultures grew non-O1 V. cholerae. At surgery, the gallbladder was acalculous, inflamed, distended, and nearly ruptured. Pathogenetic factors may have included diarrhea prophylaxis with bismuth subsalicylate, distension of the gallbladder from illness-induced fasting, and bacterial toxins in the gallbladder. The patient received i.v. cephapirin, followed by oral cephradine for a total of 10 days, and he made a quick and complete recovery. V. cholerae should be considered in the differential diagnosis of persons from endemic areas who present with cholecystitis or acute jaundice.

  19. In a time of cholera.

    Science.gov (United States)

    Grace, P A

    2014-03-01

    Dr. Nathaniel Alcock in his book A treatise on cholera described 22 cases of cholera that he treated in 1832. Blood-letting, either by leeches or venesection, was an essential part of the treatment. The belief was that reducing the blood volume would relieve stress on the heart and lungs allowing for better function. The receipts of the Townsend Street Cholera Hospital where Dr. Alcock worked show how extensive the practice was. Outside Dublin, local Boards of Health dealt with the cholera epidemic. Various public measures such as street cleaning and removal of patients to temporary hospitals were undertaken and various cures were tried. The overall mortality rate from cholera in Ireland during the epidemic was 38 %, but in some areas much higher. Even as cholera was spreading in the 1830s, a number of doctors were showing that intravenous fluids could dramatically alter the course of the disease. Unfortunately, their work was ignored and blood-letting continued to be a major component of the treatment of cholera for another 55 years.

  20. Prolonging herd immunity to cholera via vaccination: Accounting for human mobility and waning vaccine effects.

    Directory of Open Access Journals (Sweden)

    Corey M Peak

    2018-02-01

    Full Text Available Oral cholera vaccination is an approach to preventing outbreaks in at-risk settings and controlling cholera in endemic settings. However, vaccine-derived herd immunity may be short-lived due to interactions between human mobility and imperfect or waning vaccine efficacy. As the supply and utilization of oral cholera vaccines grows, critical questions related to herd immunity are emerging, including: who should be targeted; when should revaccination be performed; and why have cholera outbreaks occurred in recently vaccinated populations?We use mathematical models to simulate routine and mass oral cholera vaccination in populations with varying degrees of migration, transmission intensity, and vaccine coverage. We show that migration and waning vaccine efficacy strongly influence the duration of herd immunity while birth and death rates have relatively minimal impacts. As compared to either periodic mass vaccination or routine vaccination alone, a community could be protected longer by a blended "Mass and Maintain" strategy. We show that vaccination may be best targeted at populations with intermediate degrees of mobility as compared to communities with very high or very low population turnover. Using a case study of an internally displaced person camp in South Sudan which underwent high-coverage mass vaccination in 2014 and 2015, we show that waning vaccine direct effects and high population turnover rendered the camp over 80% susceptible at the time of the cholera outbreak beginning in October 2016.Oral cholera vaccines can be powerful tools for quickly protecting a population for a period of time that depends critically on vaccine coverage, vaccine efficacy over time, and the rate of population turnover through human mobility. Due to waning herd immunity, epidemics in vaccinated communities are possible but become less likely through complementary interventions or data-driven revaccination strategies.

  1. Cholera Vaccination Campaign Contributes to Improved Knowledge Regarding Cholera and Improved Practice Relevant to Waterborne Disease in Rural Haiti

    Science.gov (United States)

    Aibana, Omowunmi; Franke, Molly; Teng, Jessica; Hilaire, Johanne; Raymond, Max; Ivers, Louise C.

    2013-01-01

    Background Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV) might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti. Methodology/Principal Findings We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811). An OCV campaign occurred from May–June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52–2.40), preventive methods (OR 1.83; 95% CI 1.46–2.30), and water treatment modalities (OR 2.75; 95% CI 2.16–3.50). Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28–2.05). Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03–1.64). Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14–1.89). Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35–4.51). Conclusion An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti. PMID:24278498

  2. Cholera vaccination campaign contributes to improved knowledge regarding cholera and improved practice relevant to waterborne disease in rural Haiti.

    Directory of Open Access Journals (Sweden)

    Omowunmi Aibana

    2013-11-01

    Full Text Available Haiti's cholera epidemic has been devastating partly due to underlying weak infrastructure and limited clean water and sanitation. A comprehensive approach to cholera control is crucial, yet some have argued that oral cholera vaccination (OCV might result in reduced hygiene practice among recipients. We evaluated the impact of an OCV campaign on knowledge and health practice in rural Haiti.We administered baseline surveys on knowledge and practice relevant to cholera and waterborne disease to every 10th household during a census in rural Haiti in February 2012 (N = 811. An OCV campaign occurred from May-June 2012 after which we administered identical surveys to 518 households randomly chosen from the same region in September 2012. We compared responses pre- and post-OCV campaign. Post-vaccination, there was improved knowledge with significant increase in percentage of respondents with ≥ 3 correct responses on cholera transmission mechanisms (odds ratio[OR] 1.91; 95% confidence interval[CI] 1.52-2.40, preventive methods (OR 1.83; 95% CI 1.46-2.30, and water treatment modalities (OR 2.75; 95% CI 2.16-3.50. Relative to pre-vaccination, participants were more likely post-OCV to report always treating water (OR 1.62; 95% CI 1.28-2.05. Respondents were also more likely to report hand washing with soap and water >4 times daily post-vaccine (OR 1.30; 95% CI 1.03-1.64. Knowledge of treating water as a cholera prevention measure was associated with practice of always treating water (OR 1.47; 95% CI 1.14-1.89. Post-vaccination, knowledge was associated with frequent hand washing (OR 2.47; 95% CI 1.35-4.51.An OCV campaign in rural Haiti was associated with significant improvement in cholera knowledge and practices related to waterborne disease. OCV can be part of comprehensive cholera control and reinforce, not detract from, other control efforts in Haiti.

  3. Molecular Dynamics Simulation of Cholera Toxin A-1 Polypeptide

    Directory of Open Access Journals (Sweden)

    Badshah Syed Lal

    2016-01-01

    Full Text Available A molecular dynamics (MD simulation study of the enzymatic portion of cholera toxin; cholera toxin A-1 polypeptide (CTA1 was performed at 283, 310 and 323 K. From total energy analysis it was observed that this toxin is stable thermodynamically and these outcomes were likewise confirmed by root mean square deviations (RMSD investigations. The Cα root mean square fluctuation (RMSF examinations revealed that there are a number of residues inside CTA1, which can be used as target for designing and synthesizing inhibitory drugs, in order to inactivate cholera toxin inside the human body. The fluctuations in the radius of gyration and hydrogen bonding in CTA1 proved that protein unfolding and refolding were normal routine phenomena in its structure at all temperatures. Solvent accessible surface area study identified the hydrophilic nature of the CTA1, and due to this property it can be a potential biological weapon. The structural identification (STRIDE algorithm for proteins was successfully used to determine the partially disordered secondary structure of CTA1. On account of this partially disordered secondary structure, it can easily deceive the proteolytic enzymes of the endoplasmic reticulum of host cells.

  4. Immunogenicity of type 2 monovalent oral and inactivated poliovirus vaccines for type 2 poliovirus outbreak response: an open-label, randomised controlled trial.

    Science.gov (United States)

    Zaman, Khalequ; Estívariz, Concepción F; Morales, Michelle; Yunus, Mohammad; Snider, Cynthia J; Gary, Howard E; Weldon, William C; Oberste, M Steven; Wassilak, Steven G; Pallansch, Mark A; Anand, Abhijeet

    2018-03-20

    Monovalent type 2 oral poliovirus vaccine (mOPV2) and inactivated poliovirus vaccine (IPV) are used to respond to type 2 poliovirus outbreaks. We aimed to assess the effect of two mOPV2 doses on the type 2 immune response by varying the time interval between mOPV2 doses and IPV co-administration with mOPV2. We did a randomised, controlled, parallel, open-label, non-inferiority, inequality trial at two study clinics in Dhaka, Bangladesh. Healthy infants aged 6 weeks (42-48 days) at enrolment were randomly assigned (1:1:1:1) to receive two mOPV2 doses (each dose consisting of two drops [0·1 mL in total] of about 10 5 50% cell culture infectious dose of type 2 Sabin strain) at intervals of 1 week, 2 weeks, 4 weeks (standard or control group), or 4 weeks with IPV (0·5 mL of type 1 [Mahoney, 40 D-antigen units], type 2 [MEF-1, 8 D-antigen units], and type 3 [Saukett, 32 D-antigen units]) administered intramuscularly with the first mOPV2 dose. We used block randomisation, randomly selecting blocks of sizes four, eight, 12, or 16 stratified by study sites. We concealed randomisation assignment from staff managing participants in opaque, sequentially numbered, sealed envelopes. Parents and clinic staff were unmasked to assignment after the randomisation envelope was opened. Laboratory staff analysing sera were masked to assignment, but investigators analysing data and assessing outcomes were not. The primary outcome was type 2 immune response measured 4 weeks after mOPV2 administration. The primary modified intention-to-treat analysis included participants with testable serum samples before and after vaccination. A non-inferiority margin of 10% and p=0·05 (one-tailed) was used. This trial is registered at ClinicalTrials.gov, number NCT02643368, and is closed to accrual. Between Dec 7, 2015, and Jan 5, 2016, we randomly assigned 760 infants to receive two mOPV2 doses at intervals of 1 week (n=191), 2 weeks (n=191), 4 weeks (n=188), or 4 weeks plus IPV (n=190). Immune

  5. Lipopolysaccharide-specific memory B cell responses to an attenuated live cholera vaccine are associated with protection against Vibrio cholerae infection.

    Science.gov (United States)

    Haney, Douglas J; Lock, Michael D; Gurwith, Marc; Simon, Jakub K; Ishioka, Glenn; Cohen, Mitchell B; Kirkpatrick, Beth D; Lyon, Caroline E; Chen, Wilbur H; Sztein, Marcelo B; Levine, Myron M; Harris, Jason B

    2018-05-11

    The single-dose live attenuated vaccine CVD 103-HgR protects against experimental Vibrio cholerae infection in cholera-naïve adults for at least 6 months after vaccination. While vaccine-induced vibriocidal seroconversion is associated with protection, vibriocidal titers decline rapidly from their peak 1-2 weeks after vaccination. Although vaccine-induced memory B cells (MBCs) might mediate sustained protection in individuals without detectable circulating antibodies, it is unknown whether oral cholera vaccination induces a MBC response. In a study that enrolled North American adults, we measured lipopolysaccharide (LPS)- and cholera toxin (CtxB)-specific MBC responses to PXVX0200 (derived from the CVD 103-HgR strain) and assessed stool volumes following experimental Vibrio cholerae infection. We then evaluated the association between vaccine-induced MBC responses and protection against cholera. There was a significant increase in % CT-specific IgG, % LPS-specific IgG, and % LPS-specific IgA MBCs which persisted 180 days after vaccination as well as a significant association between vaccine-induced increase in % LPS-specific IgA MBCs and lower post-challenge stool volume (r = -0.56, p < 0.001). Oral cholera vaccination induces antigen-specific MBC responses, and the anamnestic LPS-specific responses may contribute to long-term protection and provide correlates of the duration of vaccine-induced protection. NCT01895855. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  6. Update: cholera--Western Hemisphere, and recommendations for treatment of cholera.

    Science.gov (United States)

    1991-08-16

    Epidemic cholera appeared in Peru in January 1991 and subsequently spread to Ecuador, Colombia, Chile, Brazil, Mexico, and Guatemala. Cholera can be a severe, life-threatening illness but is highly preventable and easily treated; however, few health-care practitioners in the United States have experience identifying and treating cholera. This report provides an update on cholera in the Western Hemisphere and provides recommendations on the clinical diagnosis and treatment of cholera in the United States.

  7. Epidemic Risk from Cholera Introductions into Mexico

    OpenAIRE

    Moore, Sean M.; Shannon, Kerry L.; Zelaya, Carla E.; Azman, Andrew S.; Lessler, Justin

    2014-01-01

    Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resultin...

  8. Adapting to the global shortage of cholera vaccines: targeted single dose cholera vaccine in response to an outbreak in South Sudan.

    Science.gov (United States)

    Parker, Lucy A; Rumunu, John; Jamet, Christine; Kenyi, Yona; Lino, Richard Laku; Wamala, Joseph F; Mpairwe, Allan M; Ciglenecki, Iza; Luquero, Francisco J; Azman, Andrew S; Cabrol, Jean-Clement

    2017-04-01

    Shortages of vaccines for epidemic diseases, such as cholera, meningitis, and yellow fever, have become common over the past decade, hampering efforts to control outbreaks through mass reactive vaccination campaigns. Additionally, various epidemiological, political, and logistical challenges, which are poorly documented in the literature, often lead to delays in reactive campaigns, ultimately reducing the effect of vaccination. In June 2015, a cholera outbreak occurred in Juba, South Sudan, and because of the global shortage of oral cholera vaccine, authorities were unable to secure sufficient doses to vaccinate the entire at-risk population-approximately 1 million people. In this Personal View, we document the first public health use of a reduced, single-dose regimen of oral cholera vaccine, and show the details of the decision-making process and timeline. We also make recommendations to help improve reactive vaccination campaigns against cholera, and discuss the importance of new and flexible context-specific dose regimens and vaccination strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Changes in intestinal fluid and mucosal immune responses to cholera toxin in Giardia muris infection and binding of cholera toxin to Giardia muris trophozoites.

    Science.gov (United States)

    Ljungström, I; Holmgren, J; Svennerholm, A M; Ferrante, A

    1985-10-01

    The effect of Giardia muris infection on the diarrheal response and gut mucosal antibody response to cholera toxin was examined in mice. The results obtained showed that the fluid accumulation in intestinal loops exposed to cholera toxin was increased in mice infected with a low number (5 X 10(4) ) of G. muris cysts compared with the response in noninfected mice. This effect was associated with a marked reduction in absorption of oral rehydration fluid from the intestine. In contrast, mice infected with a high dose (2 X 10(5) ) of cysts showed a marked decrease in fluid accumulation in response to the toxin. This decrease might be related to the finding that both G. muris and Giardia lamblia trophozoites can bind significant amounts of cholera toxin. Evidence is presented which suggests that the gut mucosal antibody response, mainly immunoglobulin A but also immunoglobulin G, to an immunization course with perorally administered cholera toxin was depressed in mice infected with G. muris. The reduction in antibody levels was particularly evident when the primary immunization was made very early after infection. The serum antitoxin antibodies to the oral immunization with cholera toxin were, however, not affected. Likewise, the delayed-type hypersensitivity response against sheep erythrocytes in animals primed subcutaneously with sheep erythrocytes was not modified during the course of G. muris infection.

  10. 9 CFR 311.3 - Hog cholera.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Hog cholera. 311.3 Section 311.3... CERTIFICATION DISPOSAL OF DISEASED OR OTHERWISE ADULTERATED CARCASSES AND PARTS § 311.3 Hog cholera. (a) The carcasses of all hogs affected with hog cholera shall be condemned. (b) Inconclusive but suspicious symptoms...

  11. Agent-based modelling of cholera diffusion

    NARCIS (Netherlands)

    Augustijn-Beckers, Petronella; Doldersum, Tom; Useya, Juliana; Augustijn, Dionysius C.M.

    2016-01-01

    This paper introduces a spatially explicit agent-based simulation model for micro-scale cholera diffusion. The model simulates both an environmental reservoir of naturally occurring V.cholerae bacteria and hyperinfectious V. cholerae. Objective of the research is to test if runoff from open refuse

  12. Influence of gamma radiation on the immunobiological and immunochemical properties of cholera exotoxin

    International Nuclear Information System (INIS)

    Nedugova, G.I.; Rubtsov, I.V.; Samojlenko, I.I.

    1984-01-01

    Native cholera exotoxin (abacterial centrifugalized deposit) has been irradiated using gamma-installations with a 60 Co source. A high inactivating effect of gamma-radiation on native cholera exotoxin is established: with the increase of radiation dose cholerogenity decreased for certain (at the dose 50 kGy) a complete inactivation of all studied series of liquid filtrate-toxin took place), activity of permeability factor and toxicity for mice decreased. A higher radiostability of dry toxin preparations as compared with the liquid ones is detected. Sterilization effect of radiation is achieved at the dose 20 kGy for liquid preparations and at the dose of 30 kGy for dry ones. When preserving the irradiated preparations of raw toxin in different temperature regimes for 6 months to 1.5 year (observation time) toxic properties are not restored, immunogenous properties do not change

  13. [Complications and treatment of cholera during pregnancy].

    Science.gov (United States)

    Figueroa Damian, R; Villagrana Zesati, R; Kasis Ariceaga, D

    1994-07-01

    Since 1961 cholera has spread in many countries reaching a pandemic form. Since 1991 Mexico has been involved in this pandemia. Near 20% of all cases of cholera in our country happen in fertile women, so the possibility of the association between cholera and pregnancy is high. We present the case of a pregnant woman, who during her third trimester presented a episode of cholera, developing premature labor. Furthermore is revised the medical literature about the general principles of the management of cholera, and the association between pregnancy and the intestinal infection.

  14. Efficacy of Atovaquone plus Proguanil for Malaria Prophylaxis in Children, and its Effect on the Immunogenicity of Live Oral Cholera (CVD103-HgR) and Typhoid (Ty21a) Vaccines

    OpenAIRE

    Gruß, Holger

    2003-01-01

    Wir führten eine randomisierte Doppelblindstudie durch, um den Einfluss der Malariachemoprophy-laxe mit Atovaquon-Proguanil auf die Antikörperantwort auf die oralen Lebendimpfungen gegen Cholera (CVD103-HgR) und Typhus (Ty21a) zu bestimmen. Dazu wurden insgesamt 330 gabuni-sche Kinder den beiden Behandlungsgruppen A-P oder Placebo zugeteilt. In diesen verblieben sie während 12 Wochen Chemoprophylaxegabe und 4 Wochen Nachsorgephase. Die Impfungen mit den oben genannten Impfstoffen erfolgte 3 ...

  15. [Seroepidemiology of cholera in Mexico].

    Science.gov (United States)

    González-Bonilla, C; Valle-Valdez, J G; Núñez-León, A; Moguel-Pech, L; Villanueva-Zamudio, A

    1994-01-01

    Antibodies against Vibrio cholerae were determined in 2352 serum samples obtained from patients with clinical diagnosis of cholera. Samples from their contacts and from healthy people living in the same communities were also analyzed. Vibriocidal antibodies with titers 1:160 or higher were observed in 25% of the samples. An increase of vibriocidal and antitoxin antibody titers were observed in 56 to 60% of the patients in which paired samples were available, one obtained in the acute phase of the disease and the other in the convalescence, confirming the diagnosis of cholera. Differences in the antibody titers were noticed when comparing the serotype according to the geographic area and the season of the year.

  16. Local perceptions of cholera and anticipated vaccine acceptance in Katanga province, Democratic Republic of Congo

    Science.gov (United States)

    2013-01-01

    Background In regions where access to clean water and the provision of a sanitary infrastructure has not been sustainable, cholera continues to pose an important public health burden. Although oral cholera vaccines (OCV) are effective means to complement classical cholera control efforts, still relatively little is known about their acceptability in targeted communities. Clarification of vaccine acceptability prior to the introduction of a new vaccine provides important information for future policy and planning. Methods In a cross-sectional study in Katanga province, Democratic Republic of Congo (DRC), local perceptions of cholera and anticipated acceptance of an OCV were investigated. A random sample of 360 unaffected adults from a rural town and a remote fishing island was interviewed in 2010. In-depth interviews with a purposive sample of key informants and focus-group discussions provided contextual information. Socio-cultural determinants of anticipated OCV acceptance were assessed with logistic regression. Results Most respondents perceived contaminated water (63%) and food (61%) as main causes of cholera. Vaccines (28%), health education (18%) and the provision of clean water (15%) were considered the most effective measures of cholera control. Anticipated vaccine acceptance reached 97% if an OCV would be provided for free. Cholera-specific knowledge of hygiene and self-help in form of praying for healing were positively associated with anticipated OCV acceptance if costs of USD 5 were assumed. Conversely, respondents who feared negative social implications of cholera were less likely to anticipate acceptance of OCVs. These fears were especially prominent among respondents who generated their income through fishing. With an increase of assumed costs to USD 10.5, fear of financial constraints was negatively associated with anticipated vaccine acceptance as well. Conclusions Results suggest a high motivation to use an OCV as long as it seems affordable. The

  17. Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008

    OpenAIRE

    Choi, Seon Young; Rashed, Shah M.; Hasan, Nur A.; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Ravel, Jacques; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R.

    2016-01-01

    ABSTRACT An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX?) V.?cholerae El Tor dominated toxigenic (CTX+) strains (2001 to 2003), but V.?cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX? V.?cholerae. Genomes of six Mexican V.?cholerae O1 strains isolated during...

  18. Treatment with Entinostat Heals Experimental Cholera by Affecting Physical and Chemical Barrier Functions of Intestinal Epithelia.

    Science.gov (United States)

    Sarker, Protim; Banik, Atanu; Stromberg, Roger; Gudmundsson, Gudmundur H; Raqib, Rubhana; Agerberth, Birgitta

    2017-07-01

    We have shown previously that oral treatment with sodium butyrate or phenylbutyrate in an experimental model of shigellosis improves clinical outcomes and induces the expression of the antimicrobial peptide CAP-18 in the large intestinal epithelia. In a subsequent study, we found that entinostat, an aroylated phenylenediamine compound, has similar therapeutic potential against shigellosis. In this study, we aimed to evaluate entinostat as a potential candidate for host-directed therapy against cholera in an experimental model. Vibrio cholerae -infected rabbits were treated with two different dose regimens of entinostat: either 0.5 mg twice daily for 2 days or 1 mg once daily for 2 days. The effects of treatment on clinical outcomes and V. cholerae shedding (CFU count in stool) were observed. Immunohistochemical analysis was carried out to assess CAP-18 expression in ileal and jejunal mucosae. The serum zonulin level was measured by an enzyme-linked immunosorbent assay (ELISA) to evaluate gut permeability. Infection of rabbits with V. cholerae downregulated CAP-18 expression in the ileal epithelium; the expression was replenished by oral treatment with entinostat at either dose regimen. The level of zonulin, a marker of gut permeability, in serum was upregulated after infection, and this upregulation was counteracted after treatment with entinostat. Entinostat treatment also led to recovery from cholera and a decline in the V. cholerae count in stool. In conclusion, the improved clinical outcome of cholera for rabbits treated with entinostat is associated with the induction of CAP-18 and the reduction of gut epithelial permeability. Copyright © 2017 American Society for Microbiology.

  19. Maladi Kolera PSA (:60) (Cholera)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about ways you can prevent the spread of cholera. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  20. Cholera in the United States

    Centers for Disease Control (CDC) Podcasts

    2011-11-08

    Anna Newton, Surveillance Epidemiologist at CDC, discusses cholera that was brought to the United States during an outbreak in Haiti and the Dominican Republic (Hispaniola).  Created: 11/8/2011 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/8/2011.

  1. How Will Climate Change Impact Cholera Outbreaks?

    Science.gov (United States)

    Nasr Azadani, F.; Jutla, A.; Rahimikolu, J.; Akanda, A. S.; Huq, A.; Colwell, R. R.

    2014-12-01

    Environmental parameters associated with cholera are well documented. However, cholera continues to be a global public health threat. Uncertainty in defining environmental processes affecting growth and multiplication of the cholera bacteria can be affected significantly by changing climate at different temporal and spatial scales, either through amplification of the hydroclimatic cycle or by enhanced variability of large scale geophysical processes. Endemic cholera in the Bengal Delta region of South Asia has a unique pattern of two seasonal peaks and there are associated with asymmetric and episodic variability in river discharge. The first cholera outbreak in spring is related with intrusion of bacteria laden coastal seawater during low river discharge. Cholera occurring during the fall season is hypothesized to be associated with high river discharge related to a cross-contamination of water resources and, therefore, a second wave of disease, a phenomenon characteristic primarily in the inland regions. Because of difficulties in establishing linkage between coarse resolutions of the Global Climate Model (GCM) output and localized disease outbreaks, the impact of climate change on diarrheal disease has not been explored. Here using the downscaling method of Support Vector Machines from HADCM3 and ECHAM models, we show how cholera outbreak patterns are changing in the Bengal Delta. Our preliminary results indicate statistically significant changes in both seasonality and magnitude in the occurrence of cholera over the next century. Endemic cholera is likely to transform into epidemic forms and new geographical areas will be at risk for cholera outbreaks.

  2. Identifying cholera "hotspots" in Uganda: An analysis of cholera surveillance data from 2011 to 2016

    OpenAIRE

    Bwire, Godfrey; Ali, Mohammad; Sack, David A.; Nakinsige, Anne; Naigaga, Martha; Debes, Amanda K.; Ngwa, Moise C.; Brooks, W. Abdullah; Garimoi Orach, Christopher

    2017-01-01

    Background Despite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country. Methodology/Principle findings We obtained district level confirmed cholera outbreak data from 2011 t...

  3. Actions of cholera toxin and the prevention and treatment of cholera

    Science.gov (United States)

    Holmgren, Jan

    1981-07-01

    The drastic intestinal secretion of fluid and electrolytes that is characteristic of cholera is the result of reasonably well understood cellular and biochemical actions of the toxin secreted by Vibrio cholerae. Based on this understanding it is possible to devise new techniques for the treatment and prophylaxis of cholera to complement those based on fluid replacement therapy and sanitation.

  4. ADP-ribosylation by cholera toxin: functional analysis of a cellular system that stimulates the enzymic activity of cholera toxin fragment A1

    International Nuclear Information System (INIS)

    Gill, D.M.; Coburn, J.

    1987-01-01

    The authors have clarified relationships between cholera toxin, cholera toxin substrates, a membrane protein S that is required for toxin activity, and a soluble protein CF that is needed for the function of S. The toxin has little intrinsic ability to catalyze ADP-ribosylations unless it encounters the active form of the S protein, which is S liganded to GTP or to a GTP analogue. In the presence of CF, S x GTP forms readily, though reversibly, but a more permanent active species, S-guanosine 5'-O-(3-thiotriphosphate) (S x GTPγS), forms over a period of 10-15 min at 37 0 C. Both guanosine 5'-O-(2-thiodiphosphate) and GTP block this quasi-permanent activation. Some S x GTPγS forms in membranes that are exposed to CF alone and then to GTPγS, with a wash in between, and it is possible that CF facilitates a G nucleotide exchange. S x GTPγS dissolved by nonionic detergents persists in solution and can be used to support the ADP-ribosylation of nucleotide-free substrates. In this circumstance, added guanyl nucleotides have no further effect. This active form of S is unstable, especially when heated, but the thermal inactivation above 45 0 C is decreased by GTPγS. Active S is required equally for the ADP-ribosylation of all of cholera toxin's protein substrates, regardless of whether they bind GTP or not. They suggest that active S interacts directly with the enzymic A 1 fragments of cholera toxin and not with any toxin substrate. The activation and activity of S are independent of the state, or even the presence, of adenylate cyclase and seem to be involved with the cyclase system only via cholera toxin. S is apparently not related by function to certain other GTP binding proteins, including p21/sup ras/, and appears to be a new GTP binding protein whose physiologic role remains to be identified

  5. Near real-time forecasting for cholera decision making in Haiti after Hurricane Matthew.

    Science.gov (United States)

    Pasetto, Damiano; Finger, Flavio; Camacho, Anton; Grandesso, Francesco; Cohuet, Sandra; Lemaitre, Joseph C; Azman, Andrew S; Luquero, Francisco J; Bertuzzo, Enrico; Rinaldo, Andrea

    2018-05-01

    Computational models of cholera transmission can provide objective insights into the course of an ongoing epidemic and aid decision making on allocation of health care resources. However, models are typically designed, calibrated and interpreted post-hoc. Here, we report the efforts of a team from academia, field research and humanitarian organizations to model in near real-time the Haitian cholera outbreak after Hurricane Matthew in October 2016, to assess risk and to quantitatively estimate the efficacy of a then ongoing vaccination campaign. A rainfall-driven, spatially-explicit meta-community model of cholera transmission was coupled to a data assimilation scheme for computing short-term projections of the epidemic in near real-time. The model was used to forecast cholera incidence for the months after the passage of the hurricane (October-December 2016) and to predict the impact of a planned oral cholera vaccination campaign. Our first projection, from October 29 to December 31, predicted the highest incidence in the departments of Grande Anse and Sud, accounting for about 45% of the total cases in Haiti. The projection included a second peak in cholera incidence in early December largely driven by heavy rainfall forecasts, confirming the urgency for rapid intervention. A second projection (from November 12 to December 31) used updated rainfall forecasts to estimate that 835 cases would be averted by vaccinations in Grande Anse (90% Prediction Interval [PI] 476-1284) and 995 in Sud (90% PI 508-2043). The experience gained by this modeling effort shows that state-of-the-art computational modeling and data-assimilation methods can produce informative near real-time projections of cholera incidence. Collaboration among modelers and field epidemiologists is indispensable to gain fast access to field data and to translate model results into operational recommendations for emergency management during an outbreak. Future efforts should thus draw together multi

  6. Epidemiology of cholera outbreaks and socio-economic characteristics of the communities in the fishing villages of Uganda: 2011-2015.

    Directory of Open Access Journals (Sweden)

    Godfrey Bwire

    2017-03-01

    Full Text Available The communities in fishing villages in the Great Lakes Region of Africa and particularly in Uganda experience recurrent cholera outbreaks that lead to considerable mortality and morbidity. We evaluated cholera epidemiology and population characteristics in the fishing villages of Uganda to better target prevention and control interventions of cholera and contribute to its elimination from those communities.We conducted a prospective study between 2011-15 in fishing villages in Uganda. We collected, reviewed and documented epidemiological and socioeconomic data for 10 cholera outbreaks that occurred in fishing communities located along the African Great Lakes and River Nile in Uganda. These outbreaks caused 1,827 suspected cholera cases and 43 deaths, with a Case-Fatality Ratio (CFR of 2.4%. Though the communities in the fishing villages make up only 5-10% of the Ugandan population, they bear the biggest burden of cholera contributing 58% and 55% of all reported cases and deaths in Uganda during the study period. The CFR was significantly higher among males than females (3.2% vs. 1.3%, p = 0.02. The outbreaks were seasonal with most cases occurring during the months of April-May. Male children under age of 5 years, and 5-9 years had increased risk. Cholera was endemic in some villages with well-defined "hotspots". Practices predisposing communities to cholera outbreaks included: the use of contaminated lake water, poor sanitation and hygiene. Additional factors were: ignorance, illiteracy, and poverty.Cholera outbreaks were a major cause of morbidity and mortality among the fishing communities in Uganda. In addition to improvements in water, sanitation, and hygiene, oral cholera vaccines could play an important role in the prevention and control of these outbreaks, particularly when targeted to high-risk areas and populations. Promotion and facilitation of access to social services including education and reduction in poverty should contribute to

  7. A national cholera epidemic with high case fatality rates--Kenya 2009.

    Science.gov (United States)

    Loharikar, Anagha; Briere, Elizabeth; Ope, Maurice; Langat, Daniel; Njeru, Ian; Gathigi, Lucy; Makayotto, Lyndah; Ismail, Abdirizak M; Thuranira, Martin; Abade, Ahmed; Amwayi, Samuel; Omolo, Jared; Oundo, Joe; De Cock, Kevin M; Breiman, Robert F; Ayers, Tracy; Mintz, Eric; O'Reilly, Ciara E

    2013-11-01

    Cholera remains endemic in sub-Saharan Africa. We characterized the 2009 cholera outbreaks in Kenya and evaluated the response. We analyzed surveillance data and estimated case fatality rates (CFRs). Households in 2 districts, East Pokot (224 cases; CFR = 11.7%) and Turkana South (1493 cases; CFR = 1.0%), were surveyed. We randomly selected 15 villages and 8 households per village in each district. Healthcare workers at 27 health facilities (HFs) were surveyed in both districts. In 2009, cholera outbreaks caused a reported 11 425 cases and 264 deaths in Kenya. Data were available from 44 districts for 6893 (60%) cases. District CFRs ranged from 0% to 14.3%. Surveyed household respondents (n = 240) were aware of cholera (97.5%) and oral rehydration solution (ORS) (87.9%). Cholera deaths were reported more frequently from East Pokot (n = 120) than Turkana South (n = 120) households (20.7% vs. 12.3%). The average travel time to a HF was 31 hours in East Pokot compared with 2 hours in Turkana South. Fewer respondents in East Pokot (9.8%) than in Turkana South (33.9%) stated that ORS was available in their village. ORS or intravenous fluid shortages occurred in 20 (76.9%) surveyed HFs. High CFRs in Kenya are related to healthcare access disparities, including availability of rehydration supplies.

  8. Influence of gamma radiation on the immunobiological and immunochemical properties of cholera exotoxin. Communication 1. Changes in the biological activity of crude cholera exotoxin under the action of ionizing radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nedugova, G I; Rubtsov, I V; Samojlenko, I I [Ministerstvo Zdravookhraneniya SSSR, Tsentral' nyj Inst. Ehpidemiologii

    1984-02-01

    Native cholera exotoxin (abacterial centrifugalized deposit) has been irradiated using gamma-installations with a /sup 60/Co source. A high inactivating effect of gamma-radiation on native cholera exotoxin is established: with the increase of radiation dose cholerogenity decreased for certain (at the dose 50 kGy) a complete inactivation of all studied series of liquid filtrate-toxin took place), activity of permeability factor and toxicity for mice decreased. A higher radiostability of dry toxin preparations as compared with the liquid ones is detected. Sterilization effect of radiation is achieved at the dose 20 kGy for liquid preparations and at the dose of 30 kGy for dry ones. When preserving the irradiated preparations of raw toxin in different temperature regimes for 6 months to 1.5 year (observation time) toxic properties are not restored, immunogenous properties do not change.

  9. Identifying cholera "hotspots" in Uganda: An analysis of cholera surveillance data from 2011 to 2016.

    Science.gov (United States)

    Bwire, Godfrey; Ali, Mohammad; Sack, David A; Nakinsige, Anne; Naigaga, Martha; Debes, Amanda K; Ngwa, Moise C; Brooks, W Abdullah; Garimoi Orach, Christopher

    2017-12-01

    Despite advance in science and technology for prevention, detection and treatment of cholera, this infectious disease remains a major public health problem in many countries in sub-Saharan Africa, Uganda inclusive. The aim of this study was to identify cholera hotspots in Uganda to guide the development of a roadmap for prevention, control and elimination of cholera in the country. We obtained district level confirmed cholera outbreak data from 2011 to 2016 from the Ministry of Health, Uganda. Population and rainfall data were obtained from the Uganda Bureau of Statistics, and water, sanitation and hygiene data from the Ministry of Water and Environment. A spatial scan test was performed to identify the significantly high risk clusters. Cholera hotspots were defined as districts whose center fell within a significantly high risk cluster or where a significantly high risk cluster was completely superimposed onto a district. A zero-inflated negative binomial regression model was employed to identify the district level risk factors for cholera. In total 11,030 cases of cholera were reported during the 6-year period. 37(33%) of 112 districts reported cholera outbreaks in one of the six years, and 20 (18%) districts experienced cholera at least twice in those years. We identified 22 districts as high risk for cholera, of which 13 were near a border of Democratic Republic of Congo (DRC), while 9 districts were near a border of Kenya. The relative risk of having cholera inside the high-risk districts (hotspots) were 2 to 22 times higher than elsewhere in the country. In total, 7 million people were within cholera hotspots. The negative binomial component of the ZINB model shows people living near a lake or the Nile river were at increased risk for cholera (incidence rate ratio, IRR = 0.98, 95% CI: 0.97 to 0.99, p cholera in a district (IRR = 0.99, 95% CI: 0.98 to 1.00, p = .02 and IRR = 1.02, 95% CI: 1.01 to 1.03, p cholera in the district. The study identified cholera

  10. Mapping the burden of cholera in sub-Saharan Africa and implications for control: an analysis of data across geographical scales.

    Science.gov (United States)

    Lessler, Justin; Moore, Sean M; Luquero, Francisco J; McKay, Heather S; Grais, Rebecca; Henkens, Myriam; Mengel, Martin; Dunoyer, Jessica; M'bangombe, Maurice; Lee, Elizabeth C; Djingarey, Mamoudou Harouna; Sudre, Bertrand; Bompangue, Didier; Fraser, Robert S M; Abubakar, Abdinasir; Perea, William; Legros, Dominique; Azman, Andrew S

    2018-03-01

    Cholera remains a persistent health problem in sub-Saharan Africa and worldwide. Cholera can be controlled through appropriate water and sanitation, or by oral cholera vaccination, which provides transient (∼3 years) protection, although vaccine supplies remain scarce. We aimed to map cholera burden in sub-Saharan Africa and assess how geographical targeting could lead to more efficient interventions. We combined information on cholera incidence in sub-Saharan Africa (excluding Djibouti and Eritrea) from 2010 to 2016 from datasets from WHO, Médecins Sans Frontières, ProMED, ReliefWeb, ministries of health, and the scientific literature. We divided the study region into 20 km × 20 km grid cells and modelled annual cholera incidence in each grid cell assuming a Poisson process adjusted for covariates and spatially correlated random effects. We combined these findings with data on population distribution to estimate the number of people living in areas of high cholera incidence (>1 case per 1000 people per year). We further estimated the reduction in cholera incidence that could be achieved by targeting cholera prevention and control interventions at areas of high cholera incidence. We included 279 datasets covering 2283 locations in our analyses. In sub-Saharan Africa (excluding Djibouti and Eritrea), a mean of 141 918 cholera cases (95% credible interval [CrI] 141 538-146 505) were reported per year. 4·0% (95% CrI 1·7-16·8) of districts, home to 87·2 million people (95% CrI 60·3 million to 118·9 million), have high cholera incidence. By focusing on the highest incidence districts first, effective targeted interventions could eliminate 50% of the region's cholera by covering 35·3 million people (95% CrI 26·3 million to 62·0 million), which is less than 4% of the total population. Although cholera occurs throughout sub-Saharan Africa, its highest incidence is concentrated in a small proportion of the continent. Prioritising high-risk areas

  11. Twee Nederlandse reizigers uit Thailand met cholera

    NARCIS (Netherlands)

    Smit, A. A.; Kuijper, E. J.; Schultz, M. J.; Wieling, W.; Speelman, P.

    1994-01-01

    Cholera is a disease rarely imported in the Netherlands. Recently a 34-year-old woman who had returned from a trip through Thailand was admitted to our hospital with complaints of vomiting, watery stools and moderate dehydration. Vibrio cholerae OI serotype Ogawa biotype El Tor was isolated from the

  12. High case fatality cholera outbreak in Western Kenya, August 2010 ...

    African Journals Online (AJOL)

    Introduction: Cholera is a disease caused by the bacterium Vibrio cholera and has been an important public health problem since its first pandemic in 1817. Kenya has had numerous outbreaks of cholera ever since it was first detected there during 1971. In August 2010 an outbreak of cholera occurred in Kuria West District ...

  13. High case fatality cholera outbreak in Western Kenya, August 2010

    African Journals Online (AJOL)

    abp

    Abstract. Introduction: Cholera is a disease caused by the bacterium Vibrio cholera and has been an important public health problem since its first pandemic in 1817. Kenya has had numerous outbreaks of cholera ever since it was first detected there during 1971. In August 2010 an outbreak of cholera occurred in Kuria ...

  14. Inactivation Data.xlsx

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data set is a spreadsheet that contains results of inactivation experiments that were conducted to to determine the effectiveness of chlorine in inactivating B....

  15. Crystallization of isoelectrically homogeneous cholera toxin

    International Nuclear Information System (INIS)

    Spangler, B.D.; Westbrook, E.M.

    1989-01-01

    Past difficulty in growing good crystals of cholera toxin has prevented the study of the crystal structure of this important protein. The authors have determined that failure of cholera toxin to crystallize well has been due to its heterogeneity. They have now succeeded in overcoming the problem by isolating a single isoelectric variant of this oligomeric protein (one A subunit and five B subunits). Cholera toxin purified by their procedure readily forms large single crystals. The crystal form has been described previously. They have recorded data from native crystals of cholera toxin to 3.0-angstrom resolution with our electronic area detectors. With these data, they have found the orientation of a 5-fold symmetry axis within these crystals, perpendicular to the screw dyad of the crystal. They are now determining the crystal structure of cholera toxin by a combination of multiple heavy-atom isomorphous replacement and density modification techniques, making use of rotational 5-fold averaging of the B subunits

  16. Repair of ultraviolet-light-induced DNA damage in Vibrio cholerae

    International Nuclear Information System (INIS)

    Das, G.; Sil, K.; Das, J.

    1981-01-01

    Repair of ultraviolet-light-induced DNA damage in a highly pathogenic Gram-negative bacterium, Vibrio cholerae, has been examined. All three strains of V. cholerae belonging to two serotypes, Inaba and Ogawa, are very sensitive to ultraviolet irradiation, having inactivation cross-sections ranging from 0.18 to 0.24 m 2 /J. Although these cells are proficient in repairing the DNA damage by a photoreactivation mechanism, they do not possess efficient dark repair systems. The mild toxinogenic strain 154 of classical Vibrios presumably lacks any excision repair mechanism and studies of irradiated cell DNA indicate that the ultraviolet-induced pyrimidine dimers may not be excised. Ultraviolet-irradiated cells after saturation of dark repair can be further photoreactivated. (Auth.)

  17. Comparison of two recombinant systems for expression of cholera toxin B subunit from Vibrio cholerae

    Directory of Open Access Journals (Sweden)

    M Boustanshenas

    2013-01-01

    Full Text Available Purpose: The aim of this study was to assess the production of recombinant cholera toxin B subunit (rCTB protein in two different expression systems (pAE_ctxB and pQE_ctxB constructs in Escherichia coli BL21 (DE3. Materials and Methods: The ctxB fragment was amplified from Vibrio cholerae O 1 ATCC14035 and cloned in pGETM-T easy vector after which it was transformed to E. coli Top 10F′ and grown on LB-ampicillin agar medium. Sequence analysis confirmed the complete ctxB gene sequence in the construct which was further subcloned to pQE-30 vector. The construct was subsequently transformed to E. coli M15 (pREP4. The recombinant pAE_ctxB and pQE_ctxB were transformed to competent E. coli BL21 (DE3 cells to express CTB protein. Result: Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE analysis showed the maximum expression of rCTB in both systems at 5 h after induction and western blot analysis confirmed the presence of recombinant CTB in blotting membranes. Conclusion: Expression of rCTB in pAE_ctxB construct was more efficient (15-fold than pQE_ctxB, and it seems that Lac UV5 in E. coli BL21 (DE3 is more compatible with the former construct. This expression system can be used to produce recombinant CTB in high yield which may enable us to study the oral tolerance or mucosal adjuvant properties of rCTB using animal models.

  18. Small-molecule inhibitors of toxT expression in Vibrio cholerae.

    Science.gov (United States)

    Anthouard, Rebecca; DiRita, Victor J

    2013-08-06

    Vibrio cholerae, a Gram-negative bacterium, infects humans and causes cholera, a severe disease characterized by vomiting and diarrhea. These symptoms are primarily caused by cholera toxin (CT), whose production by V. cholerae is tightly regulated by the virulence cascade. In this study, we designed and carried out a high-throughput chemical genetic screen to identify inhibitors of the virulence cascade. We identified three compounds, which we named toxtazin A and toxtazin B and B', representing two novel classes of toxT transcription inhibitors. All three compounds reduce production of both CT and the toxin-coregulated pilus (TCP), an important colonization factor. We present evidence that toxtazin A works at the level of the toxT promoter and that toxtazins B and B' work at the level of the tcpP promoter. Treatment with toxtazin B results in a 100-fold reduction in colonization in an infant mouse model of infection, though toxtazin A did not reduce colonization at the concentrations tested. These results add to the growing body of literature indicating that small-molecule inhibitors of virulence genes could be developed to treat infections, as alternatives to antibiotics become increasingly needed. V. cholerae caused more than 580,000 infections worldwide in 2011 alone (WHO, Wkly. Epidemiol. Rec. 87:289-304, 2012). Cholera is treated with an oral rehydration therapy consisting of water, glucose, and electrolytes. However, as V. cholerae is transmitted via contaminated water, treatment can be difficult for communities whose water source is contaminated. In this study, we address the need for new therapeutic approaches by targeting the production of the main virulence factor, cholera toxin (CT). The high-throughput screen presented here led to the identification of two novel classes of inhibitors of the virulence cascade in V. cholerae, toxtazin A and toxtazins B and B'. We demonstrate that (i) small-molecule inhibitors of virulence gene production can be

  19. Genome engineering in Vibrio cholerae

    DEFF Research Database (Denmark)

    Val, Marie-Eve; Skovgaard, Ole; Ducos-Galand, Magaly

    2012-01-01

    Although bacteria with multipartite genomes are prevalent, our knowledge of the mechanisms maintaining their genome is very limited, and much remains to be learned about the structural and functional interrelationships of multiple chromosomes. Owing to its bi-chromosomal genome architecture and its....... This difficulty was surmounted using a unique and powerful strategy based on massive rearrangement of prokaryotic genomes. We developed a site-specific recombination-based engineering tool, which allows targeted, oriented, and reciprocal DNA exchanges. Using this genetic tool, we obtained a panel of V. cholerae...

  20. Inactivation of Caliciviruses

    Directory of Open Access Journals (Sweden)

    Raymond Nims

    2013-03-01

    Full Text Available The Caliciviridae family of viruses contains clinically important human and animal pathogens, as well as vesivirus 2117, a known contaminant of biopharmaceutical manufacturing processes employing Chinese hamster cells. An extensive literature exists for inactivation of various animal caliciviruses, especially feline calicivirus and murine norovirus. The caliciviruses are susceptible to wet heat inactivation at temperatures in excess of 60 °C with contact times of 30 min or greater, to UV-C inactivation at fluence ≥30 mJ/cm2, to high pressure processing >200 MPa for >5 min at 4 °C, and to certain photodynamic inactivation approaches. The enteric caliciviruses (e.g.; noroviruses display resistance to inactivation by low pH, while the non-enteric species (e.g.; feline calicivirus are much more susceptible. The caliciviruses are inactivated by a variety of chemicals, including alcohols, oxidizing agents, aldehydes, and β-propiolactone. As with inactivation of viruses in general, inactivation of caliciviruses by the various approaches may be matrix-, temperature-, and/or contact time-dependent. The susceptibilities of the caliciviruses to the various physical and chemical inactivation approaches are generally similar to those displayed by other small, non-enveloped viruses, with the exception that the parvoviruses and circoviruses may require higher temperatures for inactivation, while these families appear to be more susceptible to UV-C inactivation than are the caliciviruses.

  1. Epidemic risk from cholera introductions into Mexico.

    Science.gov (United States)

    Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin

    2014-02-21

    Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region.

  2. The Burden of Cholera in Uganda

    Science.gov (United States)

    Bwire, Godfrey; Malimbo, Mugagga; Maskery, Brian; Kim, Young Eun; Mogasale, Vittal; Levin, Ann

    2013-01-01

    Introduction In 2010, the World Health Organization released a new cholera vaccine position paper, which recommended the use of cholera vaccines in high-risk endemic areas. However, there is a paucity of data on the burden of cholera in endemic countries. This article reviewed available cholera surveillance data from Uganda and assessed the sufficiency of these data to inform country-specific strategies for cholera vaccination. Methods The Uganda Ministry of Health conducts cholera surveillance to guide cholera outbreak control activities. This includes reporting the number of cases based on a standardized clinical definition plus systematic laboratory testing of stool samples from suspected cases at the outset and conclusion of outbreaks. This retrospective study analyzes available data by district and by age to estimate incidence rates. Since surveillance activities focus on more severe hospitalized cases and deaths, a sensitivity analysis was conducted to estimate the number of non-severe cases and unrecognized deaths that may not have been captured. Results Cholera affected all ages, but the geographic distribution of the disease was very heterogeneous in Uganda. We estimated that an average of about 11,000 cholera cases occurred in Uganda each year, which led to approximately 61–182 deaths. The majority of these cases (81%) occurred in a relatively small number of districts comprising just 24% of Uganda's total population. These districts included rural areas bordering the Democratic Republic of Congo, South Sudan, and Kenya as well as the slums of Kampala city. When outbreaks occurred, the average duration was about 15 weeks with a range of 4–44 weeks. Discussion There is a clear subdivision between high-risk and low-risk districts in Uganda. Vaccination efforts should be focused on the high-risk population. However, enhanced or sentinel surveillance activities should be undertaken to better quantify the endemic disease burden and high-risk populations

  3. Intranasal and sublingual delivery of inactivated polio vaccine.

    Science.gov (United States)

    Kraan, Heleen; Soema, Peter; Amorij, Jean-Pierre; Kersten, Gideon

    2017-05-09

    Polio is on the brink of eradication. Improved inactivated polio vaccines (IPV) are needed towards complete eradication and for the use in the period thereafter. Vaccination via mucosal surfaces has important potential advantages over intramuscular injection using conventional needle and syringe, the currently used delivery method for IPV. One of them is the ability to induce both serum and mucosal immune responses: the latter may provide protection at the port of virus entry. The current study evaluated the possibilities of polio vaccination via mucosal surfaces using IPV based on attenuated Sabin strains. Mice received three immunizations with trivalent sIPV via intramuscular injection, or via the intranasal or sublingual route. The need of an adjuvant for the mucosal routes was investigated as well, by testing sIPV in combination with the mucosal adjuvant cholera toxin. Both intranasal and sublingual sIPV immunization induced systemic polio-specific serum IgG in mice that were functional as measured by poliovirus neutralization. Intranasal administration of sIPV plus adjuvant induced significant higher systemic poliovirus type 3 neutralizing antibody titers than sIPV delivered via the intramuscular route. Moreover, mucosal sIPV delivery elicited polio-specific IgA titers at different mucosal sites (IgA in saliva, fecal extracts and intestinal tissue) and IgA-producing B-cells in the spleen, where conventional intramuscular vaccination was unable to do so. However, it is likely that a mucosal adjuvant is required for sublingual vaccination. Further research on polio vaccination via sublingual mucosal route should include the search for safe and effective adjuvants, and the development of novel oral dosage forms that improve antigen uptake by oral mucosa, thereby increasing vaccine immunogenicity. This study indicates that both the intranasal and sublingual routes might be valuable approaches for use in routine vaccination or outbreak control in the period after

  4. EPIDEMIOLOGY OF CHOLERA OUTBREAK IN KAMPALA ...

    African Journals Online (AJOL)

    hi-tech

    77 No. 7 July 2000. EPIDEMIOLOGY OF CHOLERA OUTBREAK IN KAMPALA, UGANDA ... spread much (106 cases in 1995), resulting in a low level of immunity ... An intensive social ... development of a network of community health workers,.

  5. Influence of human behavior on cholera dynamics.

    Science.gov (United States)

    Wang, Xueying; Gao, Daozhou; Wang, Jin

    2015-09-01

    This paper is devoted to studying the impact of human behavior on cholera infection. We start with a cholera ordinary differential equation (ODE) model that incorporates human behavior via modeling disease prevalence dependent contact rates for direct and indirect transmissions and infectious host shedding. Local and global dynamics of the model are analyzed with respect to the basic reproduction number. We then extend the ODE model to a reaction-convection-diffusion partial differential equation (PDE) model that accounts for the movement of both human hosts and bacteria. Particularly, we investigate the cholera spreading speed by analyzing the traveling wave solutions of the PDE model, and disease threshold dynamics by numerically evaluating the basic reproduction number of the PDE model. Our results show that human behavior can reduce (a) the endemic and epidemic levels, (b) cholera spreading speeds and (c) the risk of infection (characterized by the basic reproduction number). Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  6. Intestinal Colonization Dynamics of Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    Salvador Almagro-Moreno

    2015-05-01

    Full Text Available To cause the diarrheal disease cholera, Vibrio cholerae must effectively colonize the small intestine. In order to do so, the bacterium needs to successfully travel through the stomach and withstand the presence of agents such as bile and antimicrobial peptides in the intestinal lumen and mucus. The bacterial cells penetrate the viscous mucus layer covering the epithelium and attach and proliferate on its surface. In this review, we discuss recent developments and known aspects of the early stages of V. cholerae intestinal colonization and highlight areas that remain to be fully understood. We propose mechanisms and postulate a model that covers some of the steps that are required in order for the bacterium to efficiently colonize the human host. A deeper understanding of the colonization dynamics of V. cholerae and other intestinal pathogens will provide us with a variety of novel targets and strategies to avoid the diseases caused by these organisms.

  7. Liquid holding recovery and photoreactivation of the ultraviolet-inactivated vibrios

    International Nuclear Information System (INIS)

    Banerjee, S.K.; Chatterjee, S.N.

    1981-01-01

    The kinetics of liquid holding recovery and photoreactivation of the ultra-violet-inactivated vibrios have been investigated. Photoreactivation was highest (about 80%) for Vibrio cholerae (classical) strains but the liquid holding recovery was highest (about 29%) for Vibrio parahemolyticus ones. Significance of the differences between any two of the four vibrio biotypes in respect of their liquid holding recovery and also photoreactivation was analysed statistically. (auth.)

  8. Costs of Illness Due to Endemic Cholera

    Science.gov (United States)

    Poulos, C.; Riewpaiboon, A.; Stewart, J.F.; Clemens, J.; Guh, S.; Agtini, M.; Sur, D.; Islam, Z.; Lucas, M.; Whittington, D.

    2013-01-01

    Summary Economic analyses of cholera immunization programmes require estimates of the costs of cholera. The Diseases of the Most Impoverished programme measured the public, provider, and patient costs of culture-confirmed cholera in four study sites with endemic cholera using a combination of hospital- and community-based studies. Families with culture-proven cases were surveyed at home 7 and 14 days after confirmation of illness. Public costs were measured at local health facilities using a micro-costing methodology. Hospital-based studies found that the costs of severe cholera were USD 32 and 47 in Matlab and Beira. Community-based studies in North Jakarta and Kolkata found that cholera cases cost between USD 28 and USD 206, depending on hospitalization. Patient costs of illness as a percentage of average monthly income were 21% and 65% for hospitalized cases in Kolkata and North Jakarta, respectively. This burden on families is not captured by studies that adopt a provider perspective. PMID:21554781

  9. Cell vacuolation caused by Vibrio cholerae hemolysin.

    Science.gov (United States)

    Figueroa-Arredondo, P; Heuser, J E; Akopyants, N S; Morisaki, J H; Giono-Cerezo, S; Enríquez-Rincón, F; Berg, D E

    2001-03-01

    Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (approximately 1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (approximately 16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses.

  10. Impact of solar irradiation on cholera toxin secretion by different strains of Vibrio cholerae

    CSIR Research Space (South Africa)

    Ssemakalu, CC

    2013-09-01

    Full Text Available , Salomon RN, Garrity K, Reveillaud I, Kopin A, Jackson FR, et al. Vibrio cholerae infection of Drosophila melanogaster mimics the human disease cholera. PLoS Pathog. 2005;1(1):e8. http://dx.doi.org/10.1371/ journal.ppat.0010008 2. World Health...

  11. Comparative Genomics of Vibrio cholerae O1 Isolated from Cholera Patients in Bangladesh

    DEFF Research Database (Denmark)

    Hossain, Zenat Zebin; Leekitcharoenphon, Pimlapas; Dalsgaard, Anders

    patients was co-infected with two V. cholerae strains (VC-1 and VC-3). Major virulence factors, biotype and antimicrobial resistance genes were identified by WGS. A global phylogenetic tree was inferred using genome wide SNPs (Single Nucleotide Polymorphism) analysis. RESULTS: All the V. cholerae strains...

  12. High-resolution spatial analysis of cholera patients reported in Artibonite department, Haiti in 2010-2011.

    Science.gov (United States)

    Allan, Maya; Grandesso, Francesco; Pierre, Ronald; Magloire, Roc; Coldiron, Matthew; Martinez-Pino, Isabel; Goffeau, Thierry; Gitenet, Romain; François, Gwenola; Olson, David; Porten, Klaudia; Luquero, Francisco J

    2016-03-01

    Cholera is caused by Vibrio cholerae, and is transmitted through fecal-oral contact. Infection occurs after the ingestion of the bacteria and is usually asymptomatic. In a minority of cases, it causes acute diarrhea and vomiting, which can lead to potentially fatal severe dehydration, especially in the absence of appropriate medical care. Immunity occurs after infection and typically lasts 6-36 months. Cholera is responsible for outbreaks in many African and Asian developing countries, and caused localised and episodic epidemics in South America until the early 1990s. Haiti, despite its low socioeconomic status and poor sanitation, had never reported cholera before the recent outbreak that started in October 2010, with over 720,000 cases and over 8700 deaths (Case fatality rate: 1.2%) through 8 december 2014. So far, this outbreak has seen 3 epidemic peaks, and it is expected that cholera will remain in Haiti for some time. To trace the path of the early epidemic and to identify hot spots and potential transmission hubs during peaks, we examined the spatial distribution of cholera patients during the first two peaks in Artibonite, the second-most populous department of Haiti. We extracted the geographic origin of 84,000 patients treated in local health facilities between October 2010 and December 2011 and mapped these addresses to 63 rural communal sections and 9 urban cities. Spatial and cluster analysis showed that during the first peak, cholera spread along the Artibonite River and the main roads, and sub-communal attack rates ranged from 0.1% to 10.7%. During the second peak, remote mountain areas were most affected, although sometimes to very different degrees even in closely neighboring locations. Sub-communal attack rates during the second peak ranged from 0.2% to 13.7%. The relative risks at the sub-communal level during the second phase showed an inverse pattern compared to the first phase. These findings demonstrate the value of high-resolution mapping

  13. Household Transmission of Vibrio cholerae in Bangladesh.

    Directory of Open Access Journals (Sweden)

    Jonathan D Sugimoto

    2014-11-01

    Full Text Available Vibrio cholerae infections cluster in households. This study's objective was to quantify the relative contribution of direct, within-household exposure (for example, via contamination of household food, water, or surfaces to endemic cholera transmission. Quantifying the relative contribution of direct exposure is important for planning effective prevention and control measures.Symptom histories and multiple blood and fecal specimens were prospectively collected from household members of hospital-ascertained cholera cases in Bangladesh from 2001-2006. We estimated the probabilities of cholera transmission through 1 direct exposure within the household and 2 contact with community-based sources of infection. The natural history of cholera infection and covariate effects on transmission were considered. Significant direct transmission (p-value<0.0001 occurred among 1414 members of 364 households. Fecal shedding of O1 El Tor Ogawa was associated with a 4.9% (95% confidence interval: 0.9%-22.8% risk of infection among household contacts through direct exposure during an 11-day infectious period (mean length. The estimated 11-day risk of O1 El Tor Ogawa infection through exposure to community-based sources was 2.5% (0.8%-8.0%. The corresponding estimated risks for O1 El Tor Inaba and O139 infection were 3.7% (0.7%-16.6% and 8.2% (2.1%-27.1% through direct exposure, and 3.4% (1.7%-6.7% and 2.0% (0.5%-7.3% through community-based exposure. Children under 5 years-old were at elevated risk of infection. Limitations of the study may have led to an underestimation of the true risk of cholera infection. For instance, available covariate data may have incompletely characterized levels of pre-existing immunity to cholera infection. Transmission via direct exposure occurring outside of the household was not considered.Direct exposure contributes substantially to endemic transmission of symptomatic cholera in an urban setting. We provide the first estimate of

  14. Global climate and infectious disease: the cholera paradigm.

    Science.gov (United States)

    Colwell, R R

    1996-12-20

    The origin of cholera has been elusive, even though scientific evidence clearly shows it is a waterborne disease. However, standard bacteriological procedures for isolation of the cholera vibrio from environmental samples, including water, between epidemics generally were unsuccessful. Vibrio cholerae, a marine vibrio, requiring salt for growth, enters into a dormant, viable but nonculturable stage when conditions are unfavorable for growth and reproduction. The association of Vibrio cholerae with plankton, notably copepods, provides further evidence for the environmental origin of cholera, as well as an explanation for the sporadic and erratic occurrence of cholera epidemics. On a global scale, cholera epidemics can now be related to climate and climatic events, such as El Niño, as well as the global distribution of the plankton host. Remote sensing, with the use of satellite imagery, offers the potential for predicting conditions conducive to cholera outbreaks or epidemics.

  15. The case of cholera preparedness, response and prevention in the ...

    African Journals Online (AJOL)

    2011-10-07

    Oct 7, 2011 ... Keywords: Cholera prevention, preparedness and response, socio-political understanding of cholera, socio-cultural understanding .... cies of bacteria or viruses. ... quality such as boiling, chlorination, and filtration are not eco-.

  16. Cholera Epidemiology in Nigeria: an overview | Adagbada | Pan ...

    African Journals Online (AJOL)

    Cholera is an acute diarrhoeal infection caused by ingestion of food or water contaminated with the bacterium, Vibrio cholera. Choleragenic V. cholera O1 and O139 are the only causative agents of the disease. The two most distinguishing epidemiologic features of the disease are its tendency to appear in explosive ...

  17. Combating cholera epidemics by targeting reservoirs of infection ...

    African Journals Online (AJOL)

    Objectives: To determine the parameters which can be investigated for prevention and effective control of cholera. Data sources: Literature search on compact disk-read only memory (CD-ROM), medline and internet, using the key words: cholera outbreaks, and cholera transmission. A few reviews were manually reviewed.

  18. Cholera in Pregnancy: Outcomes from a Specialized Cholera Treatment Unit for Pregnant Women in L?og?ne, Haiti

    OpenAIRE

    Ciglenecki, Iza; Bichet, Mathieu; Tena, Javier; Mondesir, Erneau; Bastard, Mathieu; Tran, Nguyen-Toan; Antierens, Annick; Staderini, Nelly

    2013-01-01

    BACKGROUND: The association between cholera in pregnancy and negative fetal outcome has been described since the 19(th) century. However, there is limited published literature on the subject. We describe pregnancy outcomes from a specialized multidisciplinary hospital unit at the onset of a large cholera outbreak in Haiti in 2010 and 2011. METHODS: Pregnant women with cholera were hospitalized in a specialized unit within the MSF hospital compound in Léogâne and treated using standard cholera...

  19. Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008.

    Science.gov (United States)

    Choi, Seon Young; Rashed, Shah M; Hasan, Nur A; Alam, Munirul; Islam, Tarequl; Sadique, Abdus; Johura, Fatema-Tuz; Eppinger, Mark; Ravel, Jacques; Huq, Anwar; Cravioto, Alejandro; Colwell, Rita R

    2016-03-15

    An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997). Nontoxigenic (CTX(-)) V. cholerae El Tor dominated toxigenic (CTX(+)) strains (2001 to 2003), but V. cholerae CTX(+) variant El Tor was isolated during 2004 to 2008, outcompeting CTX(-) V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX(+) El Tor, two were CTX(-) El Tor, and the remaining strain was a CTX(+) classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX(-) isolate is ancestral to the 6th and 7th pandemic CTX(+) V. cholerae isolates. The other CTX(-) isolate joined with CTX(-) non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX(+) isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX(+) El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II) are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX(+) El Tor isolate contained West African-South American (WASA) recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs) and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity. Sequencing of genomes of V. cholerae is critical if genetic changes occurring over time in the circulating population of an area of endemicity are to be understood. Although cholera outbreaks occurred rarely

  20. Potential impact of reactive vaccination in controlling cholera outbreaks: an exploratory analysis using a Zimbabwean experience.

    Science.gov (United States)

    Kim, Sun-Young; Choi, Yeongchull; Mason, Peter R; Rusakaniko, Simbarashe; Goldie, Sue J

    2011-09-05

    To contain ongoing cholera outbreaks, the World Health Organization has suggested that reactive vaccination should be considered in addition to its previous control measures. To explore the potential impact of a hypothetical reactive oral cholera vaccination using the example of the recent large-scale cholera outbreak in Zimbabwe. This was a retrospective cost-effectiveness analysis calculating the health and economic burden of the cholera outbreak in Zimbabwe with and without reactive vaccination. The primary outcome measure was incremental cost per disability-adjusted life year (DALY) averted. Under the base-case assumptions (assuming 50% coverage among individuals aged ≥2 years), reactive vaccination could have averted 1 320 deaths and 23 650 DALYs. Considering herd immunity, the corresponding values would have been 2 920 deaths and 52 360 DALYs averted. The total vaccination costs would have been ~$74 million and ~$21 million, respectively, with per-dose vaccine price of US$5 and $1. The incremental costs per DALY averted of reactive vaccination were $2 770 and $370, respectively, for vaccine price set at $5 and $1. Assuming herd immunity, the corresponding cost was $980 with vaccine price of $5, and the programme was cost-saving with a vaccine price of $1. Results were most sensitive to case-fatality rate, per-dose vaccine price, and the size of the outbreak. Reactive vaccination has the potential to be a cost-effective measure to contain cholera outbreaks in countries at high risk. However, the feasibility of implementation should be further evaluated, and caution is warranted in extrapolating the findings to different settings in the absence of other in-depth studies.

  1. Phylogenetic Diversity of Vibrio cholerae Associated with Endemic Cholera in Mexico from 1991 to 2008

    Directory of Open Access Journals (Sweden)

    Seon Young Choi

    2016-03-01

    Full Text Available An outbreak of cholera occurred in 1991 in Mexico, where it had not been reported for more than a century and is now endemic. Vibrio cholerae O1 prototype El Tor and classical strains coexist with altered El Tor strains (1991 to 1997. Nontoxigenic (CTX− V. cholerae El Tor dominated toxigenic (CTX+ strains (2001 to 2003, but V. cholerae CTX+ variant El Tor was isolated during 2004 to 2008, outcompeting CTX−V. cholerae. Genomes of six Mexican V. cholerae O1 strains isolated during 1991 to 2008 were sequenced and compared with both contemporary and archived strains of V. cholerae. Three were CTX+ El Tor, two were CTX− El Tor, and the remaining strain was a CTX+ classical isolate. Whole-genome sequence analysis showed the six isolates belonged to five distinct phylogenetic clades. One CTX− isolate is ancestral to the 6th and 7th pandemic CTX+V. cholerae isolates. The other CTX− isolate joined with CTX− non-O1/O139 isolates from Haiti and seroconverted O1 isolates from Brazil and Amazonia. One CTX+ isolate was phylogenetically placed with the sixth pandemic classical clade and the V. cholerae O395 classical reference strain. Two CTX+ El Tor isolates possessing intact Vibrio seventh pandemic island II (VSP-II are related to hybrid El Tor isolates from Mozambique and Bangladesh. The third CTX+ El Tor isolate contained West African-South American (WASA recombination in VSP-II and showed relatedness to isolates from Peru and Brazil. Except for one isolate, all Mexican isolates lack SXT/R391 integrative conjugative elements (ICEs and sensitivity to selected antibiotics, with one isolate resistant to streptomycin. No isolates were related to contemporary isolates from Asia, Africa, or Haiti, indicating phylogenetic diversity.

  2. Promotion of Cholera Awareness Among Households of Cholera Patients: A Randomized Controlled Trial of the Cholera-Hospital-Based-Intervention-for-7 Days (CHoBI7) Intervention.

    Science.gov (United States)

    Saif-Ur-Rahman, K M; Parvin, Tahmina; Bhuyian, Sazzadul Islam; Zohura, Fatema; Begum, Farzana; Rashid, Mahamud-Ur; Biswas, Shwapon Kumar; Sack, David; Sack, R Bradley; Monira, Shirajum; Alam, Munirul; Shaly, Nusrat Jahan; George, Christine Marie

    2016-12-07

    Previous studies have demonstrated that household contacts of cholera patients are highly susceptible to cholera infections for a 7-day period after the presentation of the index patient in the hospital. However, there is no standard of care to prevent cholera transmission in this high-risk population. Furthermore, there is limited information available on awareness of cholera transmission and prevention among cholera patients and their household contacts. To initiate a standard of care for this high-risk population, we developed the Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which delivers a handwashing with soap and water treatment intervention to household contacts during the time they spend with the admitted cholera patient in the hospital and reinforces these messages through home visits. To test CHoBI7, we conducted a randomized controlled trial among 302 intervention cholera patient household members and 302 control cholera patient household members in Dhaka, Bangladesh. In this study, we evaluated the effectiveness of the CHoBI7 intervention in increasing awareness of cholera transmission and prevention, and the key times for handwashing with soap. We observed a significant increase in cholera knowledge score in the intervention arm compared with the control arm at both the 1-week follow-up {score coefficient = 2.34 (95% confidence interval [CI] = 1.96, 2.71)} and 6 to 12-month follow-up period (score coefficient = 1.59 [95% CI = 1.05, 2.13]). This 1-week hospital- and home-based intervention led to a significant increase in knowledge of cholera transmission and prevention which was sustained 6 to 12 months post-intervention. These findings suggest that the CHoBI7 intervention presents a promising approach to increase cholera awareness among this high-risk population. © The American Society of Tropical Medicine and Hygiene.

  3. Haiti's progress in achieving its 10-year plan to eliminate cholera: hidden sickness cannot be cured

    Directory of Open Access Journals (Sweden)

    Koski-Karell V

    2016-05-01

    the three government-sponsored water treatment stations in the research area is still functional and utilized by those who can afford it. Latrines are scarce and often shared by up to 30 people; open defecation remains common. Structural vulnerabilities cut across all sectors – not just water, sanitation, health care, and education, but agriculture, environment, (global and local commerce, transportation, and governance as well. These are among the hidden sicknesses that impede Haiti and its partners' capacity to eliminate cholera. Keywords: water, sanitation, WASH, oral cholera vaccination, elimination 

  4. Cholera in Thomas Mann's Death in Venice.

    Science.gov (United States)

    Rütten, Thomas

    2009-01-01

    The article sets the cholera motif in Thomas Mann's famous novella Death in Venice against the historical context from which it partially originates. It is shown that this motif, while undoubtedly appropriated to serve Mann's own poetic ends, has a solid grounding in historical and autobiographical fact, thus blurring the boundaries between fact and fiction. The article illustrates the verifiable events of the outbreak of the Venetian cholera epidemic in May 1911, which Mann partly witnessed himself, during a holiday trip to Brioni and Venice, and partly heard and read about. It is established that Thomas Mann's account of the cholera in Venice in his novella is characterised by a rare and almost preternatural insightfulness into an otherwise murky affair that was marked by rumours, speculations and denials.

  5. Cell Vacuolation Caused by Vibrio cholerae Hemolysin

    Science.gov (United States)

    Figueroa-Arredondo, Paula; Heuser, John E.; Akopyants, Natalia S.; Morisaki, J. Hiroshi; Giono-Cerezo, Silvia; Enríquez-Rincón, Fernando; Berg, Douglas E.

    2001-01-01

    Non-O1 strains of Vibrio cholerae implicated in gastroenteritis and diarrhea generally lack virulence determinants such as cholera toxin that are characteristic of epidemic strains; the factors that contribute to their virulence are not understood. Here we report that at least one-third of diarrhea-associated nonepidemic V. cholerae strains from Mexico cause vacuolation of cultured Vero cells. Detailed analyses indicated that this vacuolation was related to that caused by aerolysin, a pore-forming toxin of Aeromonas; it involved primarily the endoplasmic reticulum at early times (∼1 to 4 h after exposure), and resulted in formation of large, acidic, endosome-like multivesicular vacuoles (probably autophagosomes) only at late times (∼16 h). In contrast to vacuolation caused by Helicobacter pylori VacA protein, that induced by V. cholerae was exacerbated by agents that block vacuolar proton pumping but not by endosome-targeted weak bases. It caused centripetal redistribution of endosomes, reflecting cytoplasmic alkalinization. The gene for V. cholerae vacuolating activity was cloned and was found to correspond to hlyA, the structural gene for hemolysin. HlyA protein is a pore-forming toxin that causes ion leakage and, ultimately, eukaryotic cell lysis. Thus, a distinct form of cell vacuolation precedes cytolysis at low doses of hemolysin. We propose that this vacuolation, in itself, contributes to the virulence of V. cholerae strains, perhaps by perturbing intracellular membrane trafficking or ion exchange in target cells and thereby affecting local intestinal inflammatory or other defense responses. PMID:11179335

  6. Efficiency of hospital cholera treatment in Ecuador

    Directory of Open Access Journals (Sweden)

    Creamer Germán

    1999-01-01

    Full Text Available This study analyzed the efficiency of cholera treatment in three hospitals representative of the Ecuadorian public health system in order to provide hospital directors and administrators and health service policy-makers with information to plan responses to future epidemics and to reduce the costs of cholera treatment in general. For the study, total and excess cholera treatment costs were calculated using hospital files and statistics and an in-hospital surveillance system of the cholera cases. The type and quantity of each input used for each treatment were analyzed, as well as the number of days hospitalized, according to the severity of the illness. With this process, excess costs were determined in relation to a "treatment norm" that would have been appropriate for each patient. The researchers found that 45% of the cholera treatment costs were excessive. The most important contributor was excess recurrent costs (90%, including extended hospital stays, disproportionate use of intravenous rehydration solutions, and unnecessary laboratory tests. Excess capital costs, from land, buildings, and hospital equipment, represented 10% of the total excess treatment costs. No significant relationship was found between treatment costs and the severity of the illness, nor between costs and a patient's age. A patient's sex appeared to be an important variable, with the cost of treating women being notably higher than for men. An inverse relationship was found between treatment costs and the complexity of the hospital. The researchers concluded there was an inefficient use of resources in the treatment of cholera in the three hospitals where the research was performed.

  7. Vibrio cholerae as a predator: lessons from evolutionary principles

    Directory of Open Access Journals (Sweden)

    Stefan ePukatzki

    2013-12-01

    Full Text Available Diarrheal diseases are the second-most common cause of death among children under the age of five worldwide. Cholera alone, caused by the marine bacterium Vibrio cholerae, is responsible for several million cases and over 120,000 deaths annually. When contaminated water is ingested, V. cholerae passes through the gastric acid barrier, penetrates the mucin layer of the small intestine, and adheres to the underlying epithelial lining. V. cholerae multiplies rapidly, secretes cholera toxin, and exits the human host in vast numbers during diarrheal purges. How V. cholerae rapidly reaches such high numbers during each purge is not clearly understood. We propose that V. cholerae employs its bactericidal type VI secretion system to engage in intraspecies and intraguild predation for nutrient acquisition to support rapid growth and multiplication.

  8. Vibrio cholerae infection, novel drug targets and phage therapy.

    Science.gov (United States)

    Fazil, Mobashar Hussain Urf Turabe; Singh, Durg V

    2011-10-01

    Vibrio cholerae is the causative agent of the diarrheal disease cholera. Although antibiotic therapy shortens the duration of diarrhea, excessive use has contributed to the emergence of antibiotic resistance in V. cholerae. Mobile genetic elements have been shown to be largely responsible for the shift of drug resistance genes in bacteria, including some V. cholerae strains. Quorum sensing communication systems are used for interaction among bacteria and for sensing environmental signals. Sequence analysis of the ctxB gene of toxigenic V. cholerae strains demonstrated its presence in multiple cholera toxin genotypes. Moreover, bacteriophage that lyse the bacterium have been reported to modulate epidemics by decreasing the required infectious dose of the bacterium. In this article, we will briefly discuss the disease, its clinical manifestation, antimicrobial resistance and the novel approaches to locate drug targets to treat cholera.

  9. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Science.gov (United States)

    Pongkorpsakol, Pawin; Pathomthongtaweechai, Nutthapoom; Srimanote, Potjanee; Soodvilai, Sunhapas; Chatsudthipong, Varanuj; Muanprasat, Chatchai

    2014-09-01

    Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84) cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM) via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+)-K(+) ATPases and Na(+)-K(+)-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+) channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+)-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+)-activated basolateral K(+) channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment) had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT)-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg) reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+)-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  10. Inhibition of cAMP-activated intestinal chloride secretion by diclofenac: cellular mechanism and potential application in cholera.

    Directory of Open Access Journals (Sweden)

    Pawin Pongkorpsakol

    2014-09-01

    Full Text Available Cyclic AMP-activated intestinal Cl- secretion plays an important role in pathogenesis of cholera. This study aimed to investigate the effect of diclofenac on cAMP-activated Cl- secretion, its underlying mechanisms, and possible application in the treatment of cholera. Diclofenac inhibited cAMP-activated Cl- secretion in human intestinal epithelial (T84 cells with IC50 of ∼ 20 µM. The effect required no cytochrome P450 enzyme-mediated metabolic activation. Interestingly, exposures of T84 cell monolayers to diclofenac, either in apical or basolateral solutions, produced similar degree of inhibitions. Analyses of the apical Cl- current showed that diclofenac reversibly inhibited CFTR Cl- channel activity (IC50 ∼ 10 µM via mechanisms not involving either changes in intracellular cAMP levels or CFTR channel inactivation by AMP-activated protein kinase and protein phosphatase. Of interest, diclofenac had no effect on Na(+-K(+ ATPases and Na(+-K(+-Cl- cotransporters, but inhibited cAMP-activated basolateral K(+ channels with IC50 of ∼ 3 µM. In addition, diclofenac suppressed Ca(2+-activated Cl- channels, inwardly rectifying Cl- channels, and Ca(2+-activated basolateral K(+ channels. Furthermore, diclofenac (up to 200 µM; 24 h of treatment had no effect on cell viability and barrier function in T84 cells. Importantly, cholera toxin (CT-induced Cl- secretion across T84 cell monolayers was effectively suppressed by diclofenac. Intraperitoneal administration of diclofenac (30 mg/kg reduced both CT and Vibrio cholerae-induced intestinal fluid secretion by ∼ 70% without affecting intestinal fluid absorption in mice. Collectively, our results indicate that diclofenac inhibits both cAMP-activated and Ca(2+-activated Cl- secretion by inhibiting both apical Cl- channels and basolateral K+ channels in intestinal epithelial cells. Diclofenac may be useful in the treatment of cholera and other types of secretory diarrheas resulting from intestinal

  11. Non-toxigenic environmental Vibrio cholerae O1 strain from Haiti provides evidence of pre-pandemic cholera in Hispaniola

    Science.gov (United States)

    Azarian, Taj; Ali, Afsar; Johnson, Judith A.; Jubair, Mohammad; Cella, Eleonora; Ciccozzi, Massimo; Nolan, David J.; Farmerie, William; Rashid, Mohammad H.; Sinha-Ray, Shrestha; Alam, Meer T.; Morris, J. Glenn; Salemi, Marco

    2016-01-01

    Vibrio cholerae is ubiquitous in aquatic environments, with environmental toxigenic V. cholerae O1 strains serving as a source for recurrent cholera epidemics and pandemic disease. However, a number of questions remain about long-term survival and evolution of V. cholerae strains within these aquatic environmental reservoirs. Through monitoring of the Haitian aquatic environment following the 2010 cholera epidemic, we isolated two novel non-toxigenic (ctxA/B-negative) Vibrio cholerae O1. These two isolates underwent whole-genome sequencing and were investigated through comparative genomics and Bayesian coalescent analysis. These isolates cluster in the evolutionary tree with strains responsible for clinical cholera, possessing genomic components of 6th and 7th pandemic lineages, and diverge from “modern” cholera strains around 1548 C.E. [95% HPD: 1532–1555]. Vibrio Pathogenicity Island (VPI)-1 was present; however, SXT/R391-family ICE and VPI-2 were absent. Rugose phenotype conversion and vibriophage resistance evidenced adaption for persistence in aquatic environments. The identification of V. cholerae O1 strains in the Haitian environment, which predate the first reported cholera pandemic in 1817, broadens our understanding of the history of pandemics. It also raises the possibility that these and similar environmental strains could acquire virulence genes from the 2010 Haitian epidemic clone, including the cholera toxin producing CTXϕ. PMID:27786291

  12. [The immunology of cholera and the molecular biology of cholera toxin. Recent progress and future perspectives].

    Science.gov (United States)

    Carrada-Bravo, T

    1994-01-01

    Vibrio cholerae has recently called the attention of researchers due to its strong immunogenicity and also because it serves as coadjunct immunomodulator of the immune response of the intestinal mucosae for the mixed added antigens as well as for those covalently linked to the toxin. The immunopathogeny of cholera is a complex phenomenon. This article presents the preliminary results of experiments conducted with laboratory rats in order to find the IgA intestinal response of rodents and humans.

  13. Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

    OpenAIRE

    Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

    1984-01-01

    Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to thr...

  14. Persistence of plasmids, cholera toxin genes, and prophage DNA in classical Vibrio cholerae O1.

    Science.gov (United States)

    Cook, W L; Wachsmuth, K; Johnson, S R; Birkness, K A; Samadi, A R

    1984-07-01

    Plasmid profiles, the location of cholera toxin subunit A genes, and the presence of the defective VcA1 prophage genome in classical Vibrio cholerae isolated from patients in Bangladesh in 1982 were compared with those in older classical strains isolated during the sixth pandemic and with those in selected eltor and nontoxigenic O1 isolates. Classical strains typically had two plasmids (21 and 3 megadaltons), eltor strains typically had no plasmids, and nontoxigenic O1 strains had zero to three plasmids. The old and new isolates of classical V. cholerae had two HindIII chromosomal digest fragments containing cholera toxin subunit A genes, whereas the eltor strains from Eastern countries had one fragment. The eltor strains from areas surrounding the Gulf of Mexico also had two subunit A gene fragments, which were smaller and easily distinguished from the classical pattern. All classical strains had 8 to 10 HindIII fragments containing the defective VcA1 prophage genome; none of the Eastern eltor strains had these genes, and the Gulf Coast eltor strains contained a different array of weakly hybridizing genes. These data suggest that the recent isolates of classical cholera in Bangladesh are closely related to the bacterial strain(s) which caused classical cholera during the sixth pandemic. These data do not support hypotheses that either the eltor or the nontoxigenic O1 strains are precursors of the new classical strains.

  15. [A prognostic model of a cholera epidemic].

    Science.gov (United States)

    Boev, B V; Bondarenko, V M; Prokop'eva, N V; San Román, R T; Raygoza-Anaya, M; García de Alba, R

    1994-01-01

    A new model for the prognostication of cholera epidemic on the territory of a large city is proposed. This model reflects the characteristic feature of contacting infection by sensitive individuals due to the preservation of Vibrio cholerae in their water habitat. The mathematical model of the epidemic quantitatively reflects the processes of the spread of infection by kinetic equations describing the interaction of the streams of infected persons, the causative agents and susceptible persons. The functions and parameters of the model are linked with the distribution of individuals according to the duration of the incubation period and infectious process, as well as the period of asymptomatic carrier state. The computer realization of the model by means of IBM PC/AT made it possible to study the cholera epidemic which took place in Mexico in 1833. The verified model of the cholera epidemic was used for the prognostication of the possible spread of this infection in Guadalajara, taking into account changes in the epidemiological situation and the size of the population, as well as improvements in sanitary and hygienic conditions, in the city.

  16. [Mexican phenotype and genotype Vibrio cholerae 01].

    Science.gov (United States)

    Giono, S; Gutiérrez Cogno, L; Rodríguez Angeles, G; del Rio Zolezzi, A; Valdespino González, J L; Sepúlveda Amor, J

    1995-01-01

    This paper presents the phenotypical and genotypical characterization of 26922 Vibrio cholerae 01 strains isolated in Mexico from 1991 to 1993. All strains isolated were El Tor biovar. Strains were sensitive to antibiotics excluding furazolidone, streptomycin and sulfisoxasole to which we found resistance in 97% and we are using this characteristic as epidemiological markers. We detected a marked change in frequency of Inaba serotype from 1991, when it was dominant, with 99.5%, until 1992 when Ogawa serotype turned to be dominant with 95% of isolates. All Vibrio cholerae 01 strains, except one Ogawa strain, were to igenic, and V. choleraeno 01 were not toxigenic by ELISA, PCR and cell culture tests. Dominant ribotype was 5, but we found some strains with 6a pattern and two with ribotype 12. We are searching for ribotype 2 among hemolytic strains in order to learn if there is any relation to Gulf Coast strains prevalent in the USA, but until now we have not found any V. cholerae ribotype 2 in our isolates. Even if rapid tests are recommended for immediate diagnosis of cholera, it is necessary to continue bacterial isolation in order to have strains for phenotyping and genotyping studies that may support epidemiological analysis.

  17. Maladi Kolera 2 PSA (:30) (Cholera 2)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about cholera prevention and food preparation tips you can use to prevent the spread of disease. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  18. Maladi Kolera 1 PSA (:30) (Cholera 1)

    Centers for Disease Control (CDC) Podcasts

    2010-02-18

    This is an important public health announcement about cholera symptoms and ways you can prevent the spread of disease. Language: Haitian Creole.  Created: 2/18/2010 by Centers for Disease Control and Prevention (CDC).   Date Released: 2/18/2010.

  19. Cholera Epidemic Control | Zachariah | Malawi Medical Journal

    African Journals Online (AJOL)

    Malawi Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 13, No 1 (2001) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Cholera Epidemic Control. R Zachariah. Full Text: EMAIL FREE ...

  20. Fuzzy expert systems and GIS for cholera health risk prediction in southern Africa

    CSIR Research Space (South Africa)

    Fleming, GJ

    2007-01-01

    Full Text Available Cholera (Vibrio cholerae) is endemic in southern Africa and frequently breaks out in epidemics along the eastern seaboard. Extensive resources are directed at combating cholera yet it remains a significant problem. Limited resources could better...

  1. Genome assortment, not serogroup, defines Vibrio cholerae pandemic strains

    Energy Technology Data Exchange (ETDEWEB)

    Brettin, Thomas S [Los Alamos National Laboratory; Bruce, David C [Los Alamos National Laboratory; Challacombe, Jean F [Los Alamos National Laboratory; Detter, John C [Los Alamos National Laboratory; Han, Cliff S [Los Alamos National Laboratory; Munik, A C [Los Alamos National Laboratory; Chertkov, Olga [Los Alamos National Laboratory; Meincke, Linda [Los Alamos National Laboratory; Saunders, Elizabeth [Los Alamos National Laboratory; Choi, Seon Y [SEOUL NATL. UNIV.; Haley, Bradd J [U. MARYLAND; Taviani, Elisa [U. MARYLAND; Jeon, Yoon - Seong [INTL. VACCINE INST. SEOUL; Kim, Dong Wook [INTL. VACCINE INST. SEOUL; Lee, Jae - Hak [SEOUL NATL. UNIV.; Walters, Ronald A [PNNL; Hug, Anwar [NATL. INST. CHOLERIC ENTERIC DIS.; Colwell, Rita R [U. MARYLAND

    2009-01-01

    Vibrio cholerae, the causative agent of cholera, is a bacterium autochthonous to the aquatic environment, and a serious public health threat. V. cholerae serogroup O1 is responsible for the previous two cholera pandemics, in which classical and El Tor biotypes were dominant in the 6th and the current 7th pandemics, respectively. Cholera researchers continually face newly emerging and re-emerging pathogenic clones carrying combinations of new serogroups as well as of phenotypic and genotypic properties. These genotype and phenotype changes have hampered control of the disease. Here we compare the complete genome sequences of 23 strains of V. cholerae isolated from a variety of sources and geographical locations over the past 98 years in an effort to elucidate the evolutionary mechanisms governing genetic diversity and genesis of new pathogenic clones. The genome-based phylogeny revealed 12 distinct V. cholerae phyletic lineages, of which one, designated the V. cholerae core genome (CG), comprises both O1 classical and EI Tor biotypes. All 7th pandemic clones share nearly identical gene content, i.e., the same genome backbone. The transition from 6th to 7th pandemic strains is defined here as a 'shift' between pathogenic clones belonging to the same O1 serogroup, but from significantly different phyletic lineages within the CG clade. In contrast, transition among clones during the present 7th pandemic period can be characterized as a 'drift' between clones, differentiated mainly by varying composition of laterally transferred genomic islands, resulting in emergence of variants, exemplified by V.cholerae serogroup O139 and V.cholerae O1 El Tor hybrid clones that produce cholera toxin of classical biotype. Based on the comprehensive comparative genomics presented in this study it is concluded that V. cholerae undergoes extensive genetic recombination via lateral gene transfer, and, therefore, genome assortment, not serogroup, should be used to

  2. [The role of food in cholera transmission].

    Science.gov (United States)

    Dobosch, D; Gomez Zavaglia, A; Kuljich, A

    1995-01-01

    The spreading of cholera, from Peru to other Latinoamerican countries in 1991, raised questions regarding food safety, food transportation and handling. Control, prevention and risks implied in food import-export were also matters of concern. We deemed it interesting to determine the viability of Vibrio cholerae in wide consumption food locally. Selected food had different intrinsic characteristics such as: acidity (pH), water activity (aw), chemical composition, indigenous flora and other biologic and physic parameters. Twenty food products were contaminated with V. cholerae O1, Ogawa, toxigenic and not toxigenic strains: yoghurt, cream cheese, apricot marmelade, hip rose marmelade, mayonnaise, italian pasta for "empanadas", "dulce de leche", meat sausage, meat and spinach ravioli, margarine, milk dessert (made with cocoa, milk confiture, starch and additives), lettuce, tuna fish, ricotta and sterilized milk. Table I shows the viability of V. cholerae in tested foods, its pH and the reasons why the experiments were ended: 75% of the products studied could tolerate the development of the microorganism for a period ranging from one day (pasta for "empanadas") to ninety days (sterilized milk). Foods with acredity higher than pH 5.5 did not favor the growth of Vibrio. When pH was neutral or slightly acid, viability persisted independently from aw, microbial antagonisms and other physic, chemical or biologic parameters. Nevertheless, other factors such as: surface adherence, amino acids, magnesium and environmental influences not yet well determined, could eventually modify the persistence of V. cholerae in food. According to this study, most food products could tolerate growth and persistence of the infectant agent, up for three months in some cases.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

    Directory of Open Access Journals (Sweden)

    Liliana Candida Dengo-Baloi

    Full Text Available Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique.The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics.We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09, Memba (01, Tete City (08, Moatize (01, Morrumbala (01 districts, City of Quelimane (01, Lichinga (06 and Nampula (86 districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health.Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53 to Trimethoprim-, being 100% (54/54 for Ampicillin, 99% (72/74 for Nalidixic Acid, 97% (64/66 to Chloramphenicol, 95% (42/44 for Nitrofurantoin and (19/20 Cotrimoxazole, 83% (80

  4. Antibiotics resistance in El Tor Vibrio cholerae 01 isolated during cholera outbreaks in Mozambique from 2012 to 2015.

    Science.gov (United States)

    Dengo-Baloi, Liliana Candida; Semá-Baltazar, Cynthia Amino; Manhique, Lena Vania; Chitio, Jucunu Elias; Inguane, Dorteia Luísa; Langa, José Paulo

    2017-01-01

    Mozambique has recorded cyclically epidemic outbreaks of cholera. Antibiotic therapy is recommended in specific situations for management and control of cholera outbreaks. However, an increase in resistance rates to antibiotics by Vibrio cholerae has been reported in several epidemic outbreaks worldwide. On the other hand, there are few recent records of continuous surveillance of antibiotics susceptibility pattern of V. cholerae in Mozambique. The purpose of this study was to evaluate antibiotics resistance pattern of Vibrio cholerae O1 Ogawa isolated during Cholera outbreaks in Mozambique to commonly used antibiotics. We analyzed data from samples received in the context of surveillance and response to Cholera outbreaks in the National Reference Laboratory of Microbiology from the National Institute of Health of Mozambique, 159 samples suspected of cholera from cholera treatment centers of, Metangula (09), Memba (01), Tete City (08), Moatize (01), Morrumbala (01) districts, City of Quelimane (01), Lichinga (06) and Nampula (86) districts, from 2012 to 2015. Laboratory culture and standard biochemical tests were employed to isolate and identify Vibrio cholerae; serotypes were determined by antisera agglutination reaction in blade. Biotype and presence of important virulence factors analysis was done by PCR. Antibiotics susceptibility pattern was detected by disk diffusion method Kirby Bauer. Antibiotic susceptibility and results were interpreted by following as per recommendations of CLSI (Clinical and Laboratory Standards Institute) 2014. All samples were collected and tested in the context of Africhol Project, approved by the National Bioethics Committee for Health. Among isolates from of Vibrio cholerae O1 El Tor Ogawa resistance to Sulphamethoxazole-trimethropim was 100% (53/53) to Trimethoprim-, being 100% (54/54) for Ampicillin, 99% (72/74) for Nalidixic Acid, 97% (64/66) to Chloramphenicol, 95% (42/44) for Nitrofurantoin and (19/20) Cotrimoxazole, 83% (80

  5. The protective activity of tea against infection by Vibrio cholerae O1.

    Science.gov (United States)

    Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Shimamura, T

    1991-02-01

    Extracts of black tea exhibited bactericidal activity against Vibrio cholerae O1. The tea extract inhibited the haemolysin activity of V. cholerae O1, El Tor and the morphological changes of Chinese hamster ovary cells induced by cholera toxin. Tea extract also reduced fluid accumulation induced by cholera toxin in sealed adult mice and by V. cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea has protective activity against V. cholerae O1.

  6. Ultraviolet inactivation of papain

    International Nuclear Information System (INIS)

    Baugher, J.F.; Grossweiner, L.I.

    1975-01-01

    Flash photolysis transient spectra (lambda > 250 nm) of aqueous papain showed that the initial products are the neutral tryptophan radical Trp (lambdasub(max) 510 nm), the tryptophan triplet state 3 Trp (lambdasub(max) 460 nm), the disulfide bridge electron adduct -SS - - (lambdasub(max) 420 nm) and the hydrated electron esub(aq) - . The -SS - - yield was not altered by nitrous oxide or air, indicating that the formation of this product does not involve electrons in the external medium. The original papain preparation was activated by irradiating under nitrogen. The action spectrum supports previous work attributing the low initial activity to blocking of cysteinyl site 25 with a mixed disulfide. Flask lamp irradiation in nitrogen led to activation at low starting activities and inactivation at higher starting activities, while only inactivation at the same quantum yield was observed with air saturation. The results are consistent with photoionization of an essential tryptophyl residue as the key inactivating step. (author)

  7. Vibrio cholerae Colonization of Soft-Shelled Turtles.

    Science.gov (United States)

    Wang, Jiazheng; Yan, Meiying; Gao, He; Lu, Xin; Kan, Biao

    2017-07-15

    Vibrio cholerae is an important human pathogen and environmental microflora species that can both propagate in the human intestine and proliferate in zooplankton and aquatic organisms. Cholera is transmitted through food and water. In recent years, outbreaks caused by V. cholerae -contaminated soft-shelled turtles, contaminated mainly with toxigenic serogroup O139, have been frequently reported, posing a new foodborne disease public health problem. In this study, the colonization by toxigenic V. cholerae on the body surfaces and intestines of soft-shelled turtles was explored. Preferred colonization sites on the turtle body surfaces, mainly the carapace and calipash of the dorsal side, were observed for the O139 and O1 strains. Intestinal colonization was also found. The colonization factors of V. cholerae played different roles in the colonization of the soft-shelled turtle's body surface and intestine. Mannose-sensitive hemagglutinin (MSHA) of V. cholerae was necessary for body surface colonization, but no roles were found for toxin-coregulated pili (TCP) or N -acetylglucosamine-binding protein A (GBPA). Both TCP and GBPA play important roles for colonization in the intestine, whereas the deletion of MSHA revealed only a minor colonization-promoting role for this factor. Our study demonstrated that V. cholerae can colonize the surfaces and the intestines of soft-shelled turtles and indicated that the soft-shelled turtles played a role in the transmission of cholera. In addition, this study showed that the soft-shelled turtle has potential value as an animal model in studies of the colonization and environmental adaption mechanisms of V. cholerae in aquatic organisms. IMPORTANCE Cholera is transmitted through water and food. Soft-shelled turtles contaminated with Vibrio cholerae (commonly the serogroup O139 strains) have caused many foodborne infections and outbreaks in recent years, and they have become a foodborne disease problem. Except for epidemiological

  8. Inactivated poliovirus vaccine given alone or in a sequential schedule with bivalent oral poliovirus vaccine in Chilean infants: a randomised, controlled, open-label, phase 4, non-inferiority study.

    Science.gov (United States)

    O'Ryan, Miguel; Bandyopadhyay, Ananda S; Villena, Rodolfo; Espinoza, Mónica; Novoa, José; Weldon, William C; Oberste, M Steven; Self, Steve; Borate, Bhavesh R; Asturias, Edwin J; Clemens, Ralf; Orenstein, Walter; Jimeno, José; Rüttimann, Ricardo; Costa Clemens, Sue Ann

    2015-11-01

    Bivalent oral poliovirus vaccine (bOPV; types 1 and 3) is expected to replace trivalent OPV (tOPV) globally by April, 2016, preceded by the introduction of at least one dose of inactivated poliovirus vaccine (IPV) in routine immunisation programmes to eliminate vaccine-associated or vaccine-derived poliomyelitis from serotype 2 poliovirus. Because data are needed on sequential IPV-bOPV schedules, we assessed the immunogenicity of two different IPV-bOPV schedules compared with an all-IPV schedule in infants. We did a randomised, controlled, open-label, non-inferiority trial with healthy, full-term (>2·5 kg birthweight) infants aged 8 weeks (± 7 days) at six well-child clinics in Santiago, Chile. We used supplied lists to randomly assign infants (1:1:1) to receive three polio vaccinations (IPV by injection or bOPV as oral drops) at age 8, 16, and 24 weeks in one of three sequential schedules: IPV-bOPV-bOPV, IPV-IPV-bOPV, or IPV-IPV-IPV. We did the randomisation with blocks of 12 stratified by study site. All analyses were done in a masked manner. Co-primary outcomes were non-inferiority of the bOPV-containing schedules compared with the all-IPV schedule for seroconversion (within a 10% margin) and antibody titres (within two-thirds log2 titres) to poliovirus serotypes 1 and 3 at age 28 weeks, analysed in the per-protocol population. Secondary outcomes were seroconversion and titres to serotype 2 and faecal shedding for 4 weeks after a monovalent OPV type 2 challenge at age 28 weeks. Safety analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01841671, and is closed to new participants. Between April 25 and August 1, 2013, we assigned 570 infants to treatment: 190 to IPV-bOPV-bOPV, 192 to IPV-IPV-bOPV, and 188 to IPV-IPV-IPV. 564 (99%) were vaccinated and included in the intention-to-treat cohort, and 537 (94%) in the per-protocol analyses. In the IPV-bOPV-bOPV, IPV-IPV-bOPV, and IPV-IPV-IPV groups

  9. Prevalence of endoparasitic infection in children and its relation with cholera prevention efforts in Mexico.

    Science.gov (United States)

    Faulkner, Charles T; Garcia, Benito Borrego; Logan, Michael H; New, John C; Patton, Sharon

    2003-07-01

    nonpathogenic protozoan parasites such as Endolimax nana, Entamoeba coli, Entamoeba hartmanni, and I. bütschlii are important bioindicators for the persistence of unhygienic behaviors that increase the risk of cholera and other infectious diseases dependent on fecal-oral transmission. Information obtained by similar studies can be useful for monitoring compliance with community health and hygiene programs and may indicate the need to intensify educational efforts for the prevention of diarrhea associated with enteric pathogens that cannot be controlled by drugs alone.

  10. Prevalence of endoparasitic infection in children and its relation with cholera prevention efforts in Mexico

    Directory of Open Access Journals (Sweden)

    Charles T. Faulkner

    2003-07-01

    promoted for prevention of cholera. The occurrence of nonpathogenic protozoan parasites such as Endolimax nana, Entamoeba coli, Entamoeba hartmanni, and I. bütschlii are important bioindicators for the persistence of unhygienic behaviors that increase the risk of cholera and other infectious diseases dependent on fecal-oral transmission. Information obtained by similar studies can be useful for monitoring compliance with community health and hygiene programs and may indicate the need to intensify educational efforts for the prevention of diarrhea associated with enteric pathogens that cannot be controlled by drugs alone.

  11. Investigation of household contamination of Vibrio cholerae in Bangladesh

    DEFF Research Database (Denmark)

    Hossain, Zenat Zebin; Farhana, Israt; Mohan Tulsiani, Suhella

    . cholerae El Tor strain N16961, showed hemolysis and proteolysis activity but none of them exhibited any hemagglutinin activity on human erythrocytes. The study findings indicate that V. cholerae contamination is mostly originated in and around kitchen area rather than latrine area. Contaminated food...... and water supply may be the reason behind this relatively high presence of virulence factors in food plates and water pots. Direct exposure routes of disease transmission should be a major consideration in cholera prevention policies. Investigation of household contamination of Vibrio cholerae in Bangladesh......The role of in-house transmission on the incidence of Vibrio cholerae, the deadly waterborne pathogen, is still not developed. The aim of the current study was to investigate possible contamination routes in household domain for effective cholera control in Bangladesh. To examine the prevalence...

  12. The molecular epidemiology of cholera in Latin America.

    Science.gov (United States)

    Wachsmuth, I K; Evins, G M; Fields, P I; Olsvik, O; Popovic, T; Bopp, C A; Wells, J G; Carrillo, C; Blake, P A

    1993-03-01

    To explain the sudden appearance and rapid spread of cholera in Latin America in January 1991, molecular techniques were used to define Vibrio cholerae O1 isolates from around the world. Restriction fragment length polymorphisms of rRNA and ctxA genes, DNA sequence of cholera toxin B subunit gene ctxB, and multilocus enzyme electrophoresis data were used to characterize 197 isolates. Worldwide, there are at least four distinct toxigenic El Tor V. cholerae O1 clones: the seventh pandemic (Eastern Hemisphere), US Gulf Coast, Australian, and Latin American. Nontoxigenic V. cholerae O1 previously isolated in Brazil, Mexico, and Peru are unlike current toxigenic isolates. The Latin American clone probably represents an extension of the seventh pandemic into the Western Hemisphere, while the US Gulf Coast clone most likely evolved separately. These data will be useful in monitoring the spread of cholera, determining the origin of outbreaks in both hemispheres, and implicating specific vehicles of transmission.

  13. The potential impact of case-area targeted interventions in response to cholera outbreaks: A modeling study.

    Science.gov (United States)

    Finger, Flavio; Bertuzzo, Enrico; Luquero, Francisco J; Naibei, Nathan; Touré, Brahima; Allan, Maya; Porten, Klaudia; Lessler, Justin; Rinaldo, Andrea; Azman, Andrew S

    2018-02-01

    Cholera prevention and control interventions targeted to neighbors of cholera cases (case-area targeted interventions [CATIs]), including improved water, sanitation, and hygiene, oral cholera vaccine (OCV), and prophylactic antibiotics, may be able to efficiently avert cholera cases and deaths while saving scarce resources during epidemics. Efforts to quickly target interventions to neighbors of cases have been made in recent outbreaks, but little empirical evidence related to the effectiveness, efficiency, or ideal design of this approach exists. Here, we aim to provide practical guidance on how CATIs might be used by exploring key determinants of intervention impact, including the mix of interventions, "ring" size, and timing, in simulated cholera epidemics fit to data from an urban cholera epidemic in Africa. We developed a micro-simulation model and calibrated it to both the epidemic curve and the small-scale spatiotemporal clustering pattern of case households from a large 2011 cholera outbreak in N'Djamena, Chad (4,352 reported cases over 232 days), and explored the potential impact of CATIs in simulated epidemics. CATIs were implemented with realistic logistical delays after cases presented for care using different combinations of prophylactic antibiotics, OCV, and/or point-of-use water treatment (POUWT) starting at different points during the epidemics and targeting rings of various radii around incident case households. Our findings suggest that CATIs shorten the duration of epidemics and are more resource-efficient than mass campaigns. OCV was predicted to be the most effective single intervention, followed by POUWT and antibiotics. CATIs with OCV started early in an epidemic focusing on a 100-m radius around case households were estimated to shorten epidemics by 68% (IQR 62% to 72%), with an 81% (IQR 69% to 87%) reduction in cases compared to uncontrolled epidemics. These same targeted interventions with OCV led to a 44-fold (IQR 27 to 78) reduction in

  14. Updated Global Burden of Cholera in Endemic Countries

    Science.gov (United States)

    Ali, Mohammad; Nelson, Allyson R.; Lopez, Anna Lena; Sack, David A.

    2015-01-01

    Background The global burden of cholera is largely unknown because the majority of cases are not reported. The low reporting can be attributed to limited capacity of epidemiological surveillance and laboratories, as well as social, political, and economic disincentives for reporting. We previously estimated 2.8 million cases and 91,000 deaths annually due to cholera in 51 endemic countries. A major limitation in our previous estimate was that the endemic and non-endemic countries were defined based on the countries’ reported cholera cases. We overcame the limitation with the use of a spatial modelling technique in defining endemic countries, and accordingly updated the estimates of the global burden of cholera. Methods/Principal Findings Countries were classified as cholera endemic, cholera non-endemic, or cholera-free based on whether a spatial regression model predicted an incidence rate over a certain threshold in at least three of five years (2008-2012). The at-risk populations were calculated for each country based on the percent of the country without sustainable access to improved sanitation facilities. Incidence rates from population-based published studies were used to calculate the estimated annual number of cases in endemic countries. The number of annual cholera deaths was calculated using inverse variance-weighted average case-fatality rate (CFRs) from literature-based CFR estimates. We found that approximately 1.3 billion people are at risk for cholera in endemic countries. An estimated 2.86 million cholera cases (uncertainty range: 1.3m-4.0m) occur annually in endemic countries. Among these cases, there are an estimated 95,000 deaths (uncertainty range: 21,000-143,000). Conclusion/Significance The global burden of cholera remains high. Sub-Saharan Africa accounts for the majority of this burden. Our findings can inform programmatic decision-making for cholera control. PMID:26043000

  15. The Orphans of Cholera Morbus in Yucatan, 1833

    OpenAIRE

    Elsa Malvido; Paola Peniche Moreno

    2013-01-01

    This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socia...

  16. Vibrio cholerae Classical Biotype Strains Reveal Distinct Signatures in Mexico

    OpenAIRE

    Alam, Munirul; Islam, M. Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A.; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R.; Cravioto, Alejandro

    2012-01-01

    Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 199...

  17. Human Gut Microbiota Predicts Susceptibility to Vibrio cholerae Infection.

    Science.gov (United States)

    Midani, Firas S; Weil, Ana A; Chowdhury, Fahima; Begum, Yasmin A; Khan, Ashraful I; Debela, Meti D; Durand, Heather K; Reese, Aspen T; Nimmagadda, Sai N; Silverman, Justin D; Ellis, Crystal N; Ryan, Edward T; Calderwood, Stephen B; Harris, Jason B; Qadri, Firdausi; David, Lawrence A; LaRocque, Regina C

    2018-04-12

    Cholera is a public health problem worldwide and the risk factors for infection are only partially understood. We prospectively studied household contacts of cholera patients to compare those who were infected with those who were not. We constructed predictive machine learning models of susceptibility using baseline gut microbiota data. We identified bacterial taxa associated with susceptibility to Vibrio cholerae infection and tested these taxa for interactions with V. cholerae in vitro. We found that machine learning models based on gut microbiota predicted V. cholerae infection as well as models based on known clinical and epidemiological risk factors. A 'predictive gut microbiota' of roughly 100 bacterial taxa discriminated between contacts who developed infection and those who did not. Susceptibility to cholera was associated with depleted levels of microbes from the phylum Bacteroidetes. By contrast, a microbe associated with cholera by our modeling framework, Paracoccus aminovorans, promoted the in vitro growth of V. cholerae. Gut microbiota structure, clinical outcome, and age were also linked. These findings support the hypothesis that abnormal gut microbial communities are a host factor related to V. cholerae susceptibility.

  18. Potential for Controlling Cholera Using a Ring Vaccination Strategy: Re-analysis of Data from a Cluster-Randomized Clinical Trial.

    Directory of Open Access Journals (Sweden)

    Mohammad Ali

    2016-09-01

    Full Text Available Vaccinating a buffer of individuals around a case (ring vaccination has the potential to target those who are at highest risk of infection, reducing the number of doses needed to control a disease. We explored the potential vaccine effectiveness (VE of oral cholera vaccines (OCVs for such a strategy.This analysis uses existing data from a cluster-randomized clinical trial in which OCV or placebo was given to 71,900 participants in Kolkata, India, from 27 July to 10 September 2006. Cholera surveillance was then conducted on 144,106 individuals living in the study area, including trial participants, for 5 y following vaccination. First, we explored the risk of cholera among contacts of cholera patients, and, second, we measured VE among individuals living within 25 m of cholera cases between 8 and 28 d after onset of the index case. For the first analysis, individuals living around each index case identified during the 5-y period were assembled using a ring to define cohorts of individuals exposed to cholera index cases. An index control without cholera was randomly selected for each index case from the same population, matched by age group, and individuals living around each index control were assembled using a ring to define cohorts not exposed to cholera cases. Cholera attack rates among the exposed and non-exposed cohorts were compared using different distances from the index case/control to define the rings and different time frames to define the period at risk. For the VE analysis, the exposed cohorts were further stratified according to the level of vaccine coverage into high and low coverage strata. Overall VE was assessed by comparing the attack rates between high and low vaccine coverage strata irrespective of individuals' vaccination status, and indirect VE was assessed by comparing the attack rates among unvaccinated members between high and low vaccine coverage strata. Cholera risk among the cohort exposed to cholera cases was 5

  19. Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country

    OpenAIRE

    Yan Boucher

    2016-01-01

    ABSTRACT Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50?years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these coun...

  20. A localized outbreak of cholera due to vibrio cholerae, ogawa resistant to tetracyclines

    International Nuclear Information System (INIS)

    Ahmed, S.

    2015-01-01

    To study the clinical and laboratory parameters of a localized Cholera outbreak and determine the sensitivity pattern of the subtype involved. Study Design: A descriptive study. Place and Duration of Study: Combined Military Hospital, Lahore. Duration of Study: Two weeks. Patients and Methods: The study is about a localized outbreak of cholera in a group of soldiers, who consumed water from a single contaminated source of water. We are presenting here an account of the clinical and laboratory parameters of 39 hospitalized cases of cholera, who presented with profuse watery diarrhoea and vomiting. There vital signs, hydration status and systemic examination findings were recorded. Stool samples were sent for routine and microscopic examination and bacteriological culture. Blood samples were taken for complete blood count, serum sodium, potassium, urea and creatinine examination. SPSS 18 was used for statistical analysis of the results. Results: The average age of thirty nine men studied in this outbreak was 24.9 ± 6.9 years. There was no statistically significant difference between confirmed and suspected cholera cases on descriptive analysis of the clinical and laboratory parameters. Majority of patients showed pre-renal azotemia which improved within 48 to 72 hours of hospitalization. Stool cultures isolated Vibrio cholerae, subtype Ogawa, which was resistant to tetracyclines, cotrimoxazole and nalidixic acid but sensitive to fluoroquinolones and third generation cephalosporins. The outbreak was controlled when the contaminated water source was sealed and rectified. Conclusion: Multiple drug resistance strains of Vibrio cholera are causing large outbreaks which should be controlled by prevention of the disease and avoiding inappropriate use of antibiotics. (author)

  1. CHOLERA EL-TOR EN IRAN

    Directory of Open Access Journals (Sweden)

    M. Ghodssi

    1969-01-01

    Full Text Available The bacteriological analysis shows that we have been confronted with the ELTor type, and only that type, until the end of the epidemic.The clinical study presents the symptoms of the real cholera with all its grievous consequences.The epidemiological supertnisicn stales that the El..Tor cholera is not agressiveat all in town areas whereas it presents its usual aspect in country areas, because of a lack of hygiene. there.That disease can be completely cured if the balance between the electrolytesis quickly restored.The disease was all the more dreadful since it came as a surprise and spread from one province to the other.L'examen bacteriologique montrc qu'il s'agit du type EI_ Tor et uniquement du meme type jusqu'a la fin de l'epldemie.La surveillance epidemiologique constate que Ie cholera EI_Tor n'cst nullement agressif dans Ie milieu urbain; mais qu'H revet l'aspect classique dans les milieuxruraux, depourvus d'hyglene.La maludic est totalement guerissablc a condition que l'equilibre des electrolytes so it rapidement retabli. L'evenement a tHe maladie se repandit d'une12

  2. Spatially explicit modelling of cholera epidemics

    Science.gov (United States)

    Finger, F.; Bertuzzo, E.; Mari, L.; Knox, A. C.; Gatto, M.; Rinaldo, A.

    2013-12-01

    Epidemiological models can provide crucial understanding about the dynamics of infectious diseases. Possible applications range from real-time forecasting and allocation of health care resources to testing alternative intervention mechanisms such as vaccines, antibiotics or the improvement of sanitary conditions. We apply a spatially explicit model to the cholera epidemic that struck Haiti in October 2010 and is still ongoing. The dynamics of susceptibles as well as symptomatic and asymptomatic infectives are modelled at the scale of local human communities. Dissemination of Vibrio cholerae through hydrological transport and human mobility along the road network is explicitly taken into account, as well as the effect of rainfall as a driver of increasing disease incidence. The model is calibrated using a dataset of reported cholera cases. We further model the long term impact of several types of interventions on the disease dynamics by varying parameters appropriately. Key epidemiological mechanisms and parameters which affect the efficiency of treatments such as antibiotics are identified. Our results lead to conclusions about the influence of different intervention strategies on the overall epidemiological dynamics.

  3. Local population and regional environmental drivers of cholera in Bangladesh

    Directory of Open Access Journals (Sweden)

    Escamilla Veronica

    2010-01-01

    Full Text Available Abstract Background Regional environmental factors have been shown to be related to cholera. Previous work in Bangladesh found that temporal patterns of cholera are positively related to satellite-derived environmental variables including ocean chlorophyll concentration (OCC. Methods This paper investigates whether local socio-economic status (SES modifies the effect of regional environmental forces. The study area is Matlab, Bangladesh, an area of approximately 200,000 people with an active health and demographic surveillance system. Study data include (1 spatially-referenced demographic and socio-economic characteristics of the population; (2 satellite-derived variables for sea surface temperature (SST, sea surface height (SSH, and OCC; and (3 laboratory confirmed cholera case data for the entire population. Relationships between cholera, the environmental variables, and SES are measured using generalized estimating equations with a logit link function. Additionally two separate seasonal models are built because there are two annual cholera epidemics, one pre-monsoon, and one post-monsoon. Results SES has a significant impact on cholera occurrence: the higher the SES score, the lower the occurrence of cholera. There is a significant negative association between cholera incidence and SSH during the pre-monsoon period but not for the post-monsoon period. OCC is positively associated with cholera during the pre-monsoon period but not for the post-monsoon period. SST is not related to cholera incidence. Conclusions Overall, it appears cholera is influenced by regional environmental variables during the pre-monsoon period and by local-level variables (e.g., water and sanitation during the post-monsoon period. In both pre- and post-monsoon seasons, SES significantly influences these patterns, likely because it is a proxy for poor water quality and sanitation in poorer households.

  4. Fucosylation and protein glycosylation create functional receptors for cholera toxin

    DEFF Research Database (Denmark)

    Wands, Amberlyn M; Fujita, Akiko; McCombs, Janet E

    2015-01-01

    Cholera toxin (CT) enters and intoxicates host cells after binding cell surface receptors using its B subunit (CTB). The ganglioside (glycolipid) GM1 is thought to be the sole CT receptor; however, the mechanism by which CTB binding to GM1 mediates internalization of CT remains enigmatic. Here we...... in normal human intestinal epithelia and could play a role in cholera....

  5. Synthesis of protein in intestinal cells exposed to cholera toxin

    International Nuclear Information System (INIS)

    Peterson, J.W.; Berg, W.D. Jr.; Coppenhaver, D.H.

    1987-01-01

    The mechanism by which cyclic adenosine monophosphate (AMP), formed by intestinal epithelial cells in response to cholera toxin, ultimately results in alterations in water and electrolyte transport is poorly understood. Several studies have indicated that inhibitors of transcription or translation block much of the transport of ions and water in the intestine and edema formation in tissue elicited by cholera toxin. Data presented in this study confirmed the inhibitory effects of cycloheximide on cholera toxin-induced fluid accumulation in the rabbit intestinal loop model. Neither cycloheximide nor actinomycin D altered the amount of cyclic AMP that accumulated in intestinal cells and Chinese hamster ovary cells exposed to cholera toxin. An increase in [ 3 H] leucine incorporation was readily demonstrable in intestinal epithelial cells from rabbits challenged with Vibrio cholerae. Similarly, intestinal epithelial cells incubated with cholera toxin for 4 hr synthesized substantially more protein than controls as determined by relative incorporation of [ 35 S] methionine. Most of the new protein synthesized in response to cholera toxin was membrane associated and of high molecular weight. The possible significance of the toxin-induced protein relative to cholera pathogenesis was discussed

  6. Cholera outbreak in districts around Lake Chilwa, Malawi: Lessons ...

    African Journals Online (AJOL)

    Cholera is endemic in Malawi with seasonal outbreaks during the wet season. People living around Lake Chilwa rely on the lake for their water supply. From May 2009 to May 2010, a cholera outbreak occurred in fishing communities around Lake Chilwa. This paper describes the outbreak response and lessons learned for ...

  7. Dealing with cholera: exclusively the domain of environmental ...

    African Journals Online (AJOL)

    Cholera outbreaks have a profound impact on the health and well-being of communities. Especially young children are vulnerable to the disease and schools report high absenteeism during epidemics. There is both the perception and evidence thereof, that educating communities about cholera (its prevention and ...

  8. Cultural influences behind cholera transmission in the Far North ...

    African Journals Online (AJOL)

    Introduction: in recent years, the Far North Region of Cameroon has experienced serious and recurrent cholera outbreaks. Yet, understanding of cultural influences on outbreaks and spread remain poorly understood. This qualitative study explored cultural influences on cholera exposure in this region. Methods: interviews ...

  9. Risk factors associated with cholera in Harare City, Zimbabwe, 2008 ...

    African Journals Online (AJOL)

    Objective: Two suspected cholera cases at Beatrice Road Infectious Diseases Hospital were reported to Harare City Health on 14 October 2008 setting in motion investigation and control measures. We determined the extent of the epidemic and risk factors for contracting cholera. Methods: An unmatched 1:1 case-control ...

  10. The cholera epidemic in South Africa, 1980 - 1987 Epidemiological ...

    African Journals Online (AJOL)

    During the cholera epidemic in South Africa, 1980-1987, 25251 cases of cholera were bacteriologically proven. The case-fatality rate was 1,4%. Outbreaks occurred in the summer rainfall season. Age-specific aUack rates followed the pattern typically found during the 'epidemic phase' of the disease in most years. The vast ...

  11. Geographical patterns of cholera in Mexico, 1991-1996.

    Science.gov (United States)

    Borroto, R J; Martinez-Piedra, R

    2000-08-01

    The seventh cholera pandemic has been ongoing in Mexico since 1991 and threatens to become endemic. This paper aims to determine the geographical pattern of cholera in Mexico to define areas at high risk of endemic cholera. Ecologic research was conducted based upon the cartography of disease incidence. The 32 Mexican states were grouped into five strata according to the value of the 1991-1996 cumulative incidence rate of cholera. Rate ratios were computed for strata of states classified by geographical situation, urbanization, and poverty level. Cholera incidence was 2.47 times higher in coastal states than in the interior (95% CI : 2.42-2.52). The disease was negatively associated with urbanization. Incidence in the least urbanized stratum was four times as high as in the most urban stratum (95% CI : 3.9-4.12). The poorest stratum showed the most remarkable incidence, i.e. 5.9 times higher than the rate in the least poor stratum (95% CI : 5.73-6.04). This ecologic research suggests that high poverty level, low urbanization, and southern location are the most important predictors of endemic cholera in Mexican states. It is hypothesized that the natural environment of the coastal plains in southern states may also play a significant role in cholera incidence. Poor communities residing in the southern, predominantly rural, coastal states should be prioritized when it comes to investing in safe water supply facilities, adequate excreta disposal systems and cholera surveillance.

  12. Detection of viable toxigenic Vibrio cholerae and virulent Shigella ...

    African Journals Online (AJOL)

    . cholerae and the invasion plasmid antigen gene (ipaH) of virulent Shigella spp., was performed and the PCR products were visualised by agarose gel electrophoresis. The assay allowed the detection of as few as 1 cfu/100 ml of V. cholerae ...

  13. antimicrobial susceptibility pattern of vibrio cholerae 01 strains

    African Journals Online (AJOL)

    hi-tech

    East African Medical Journal Vol. 77 No. 7 July 2000. ANTIMICROBIAL SUSCEPTIBILITY PATTERN OF VIBRIO CHOLERAE 01 STRAINS DURING TWO CHOLERA OUTBREAKS IN DAR ES SALAAM,. TANZANIA. W.K. Urassa, MD, MSc, MMed, Lecturer, Department of Microbiology and Immunology, Muhimbili University ...

  14. First Wave of the 2016-17 Cholera Outbreak in Hodeidah City, Yemen - ACF Experience and Lessons Learned.

    Science.gov (United States)

    Altmann, Mathias; Suarez-Bustamante, Miguel; Soulier, Celine; Lesavre, Celine; Antoine, Caroline

    2017-10-13

    Although cases were reported only in 2010 and 2011, cholera is probably endemic in Yemen. In the context of a civil war, a cholera outbreak was declared in different parts of the country October 6th, 2016. This paper describes the ACF outbreak response in Hodeidah city from October 28th, 2016 to February 28th, 2017 in order to add knowledge to this large outbreak. The ACF outbreak response in Hodeidah city included a case management component and prevention measures in the community. In partnership with the Ministry of Public Health and Population of Yemen (MoPHP), the case management component included a Cholera Treatment Center (CTC) implemented in the Al Thoraw hospital, 11 Oral Rehydration Therapy Corners (ORTCs) and an active case finding system. In partnership with other stakeholders, prevention measures in the community, including access to safe water and hygiene promotion, were implemented in the most affected communities of the city. From October 28th, 2016 until February 28th, 2017, ACF provided care to 8,270 Acute Watery Diarrhea (AWD) cases, of which 5,210 (63%) were suspected cholera cases, in the CTC and the 11 ORTCs implemented in Hodeidah city. The attack rate was higher among people living in Al Hali district, with a peak in November 2016. At the CTC, 8% of children under 5 years-old also presented with Severe Acute Malnutrition (SAM). The Case-Fatality Rate (CFR) was low (0.07%) but 15% of admitted cases defaulted for cultural and security reasons. Environmental management lacked the information to appropriately target affected areas. Financial resources did not allow complete coverage of the city. Response to the first wave of a large cholera outbreak in Hodeidah city was successful in maintaining a CFR Yemen and its water infrastructure, much more efforts are needed to control the current outbreak resurgence.

  15. Estimating effects of improved drinking water and sanitation on cholera.

    Science.gov (United States)

    Leidner, Andrew J; Adusumilli, Naveen C

    2013-12-01

    Demand for adequate provision of drinking-water and sanitation facilities to promote public health and economic growth is increasing in the rapidly urbanizing countries of the developing world. With a panel of data on Asia and Africa from 1990 to 2008, associations are estimated between the occurrence of cholera outbreaks, the case rates in given outbreaks, the mortality rates associated with cholera and two disease control mechanisms, drinking-water and sanitation services. A statistically significant and negative effect is found between drinking-water services and both cholera case rates as well as cholera-related mortality rates. A relatively weak statistical relationship is found between the occurrence of cholera outbreaks and sanitation services.

  16. USE OF MODIFIED CAMP TEST FOR PRELIMINARY NONSEROLOGIC IDENTIFICATION OF VIBRIO CHOLERAE IN STOOL SPECIMENS

    Directory of Open Access Journals (Sweden)

    Murad Lesmana

    2012-09-01

    Full Text Available Suatu modifikasi uji CAMP digunakan bersama dengan reaksi biokimiawi untuk identifikasi Vibrio cholerae pada sampel klinis. Dari 579 usap dubur penderita diare, 92 (16% memberikan hasil isolasi V. cholerae 01 biotipe El Tor dan 34 (6% V. cholerae non-01. Semua isolat V. cholerae 01 El Tor menunjukkan reaksi CAMP positif kuat dengan gambaran hemolisis sinergistik lengkap berbentuk sosis; sedangkan V. cholerae non-01 memberikan reaksi CAMP yang sempit dengan pola hemolisis menyerupai bulan sabit. Hasil uji CAMP yang dilakukan bersama dengan reaksi biokimiawi sesuai dengan metode biakan konvensional yang menyertakan tes aglutinasi dengan antiserum V. cholerae 01 untuk mengidentifikasi V. cholerae.

  17. Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

    NARCIS (Netherlands)

    Garza, D.R.; Thompson, C.C.; Loureiro, E.C.; Dutilh, B.E.; Inada, D.T.; Junior, E.C.; Cardoso, J.F.; Nunes, M.R.; Lima, C.P. de; Silvestre, R.V.; Nunes, K.N.; Santos, E.C.; Edwards, R.A.; Vicente, A.C.; Sa Morais, L.L. de

    2012-01-01

    The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic

  18. The health economics of cholera: A systematic review.

    Science.gov (United States)

    Hsiao, Amber; Hall, Angela H; Mogasale, Vittal; Quentin, Wilm

    2018-06-12

    Vibrio cholera is a major contributor of diarrheal illness that causes significant morbidity and mortality globally. While there is literature on the health economics of diarrheal illnesses more generally, few studies have quantified the cost-of-illness and cost-effectiveness of cholera-specific prevention and control interventions. The present systematic review provides a comprehensive overview of the literature specific to cholera as it pertains to key health economic measures. A systematic review was performed with no date restrictions up through February 2017 in PubMed, Econlit, Embase, Web of Science, and Cochrane Review to identify relevant health economics of cholera literature. After removing duplicates, a total of 1993 studies were screened and coded independently by two reviewers, resulting in 22 relevant studies. Data on population, methods, and results (cost-of-illness and cost-effectiveness of vaccination) were compared by country/region. All costs were adjusted to 2017 USD for comparability. Costs per cholera case were found to be rather low: $1000/case. There is adequate evidence to support the economic value of vaccination for the prevention and control of cholera when vaccination is targeted at high-incidence populations and/or areas with high case fatality rates due to cholera. When herd immunity is considered, vaccination also becomes a cost-effective option for the general population and is comparable in cost-effectiveness to other routine immunizations. Cholera vaccination is a viable short-to-medium term option, especially as the upfront costs of building water, sanitation, and hygiene (WASH) infrastructure are considerably higher for countries that face a significant burden of cholera. While WASH may be the more cost-effective solution in the long-term when implemented properly, cholera vaccination can still be a feasible, cost-effective strategy. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Coliform and Vibrio cholerae Analysis of Drinking Water Collected from Cholera Outbreak Region of Bhaktapur Municipality

    Directory of Open Access Journals (Sweden)

    Upendra Thapa Shrestha

    2014-09-01

    Full Text Available Water borne infections in Nepal, especially in Kathmandu valley is one the major public health problems, causing thousands of deaths every year. Among three cities in the valley, the water borne infection including cholera is most predominant in Bhaktapur district. So the study was carried out to know the microbial drinking water quality in the city and to determine the prevalence of water borne infections in the specified region of the district in 2012. Altogether eighty (two samples from a single site at different interval-2/3 days water samples were collected from Bhaktapur Municipality, one of the most vulnerable regions for water borne diseases, following standard methods as described by APHA, 2010. All samples were transferred to Microbiology laboratory of Khwopa College, Dekocha, Bhaktapur and preceded immediately for Microbial analysis. The coliform density in the water samples were determined by Most Probable Number (MPN method followed by microscopy, colonial morphology and biochemical characterization. Subsequently, the presence of Vibrio cholerae, a causative agent of Cholera was analyzed in the same samples by enrichment in alkaline peptone water followed by culture on Thiosulphate citrate bile-salt sucrose (TCBS agar, a selective media for Vibrio spp. The biochemical tests were then performed to identify V. cholerae. Among eighty water samples, 87.5 percent water samples contained coliforms and half of which (45% contained feacal coliforms, Escherichia coli and remaining 12.5 percent water samples contained no coliforms. Vibrio cholerae were isolated from four water samples (5%. The drinking water quality in the region was found to be very poor. Therefore, the people in the region were suggested to treat the drinking water by using any of physical or chemical disinfection methods prior to drinking. DOI: http://dx.doi.org/10.3126/ije.v3i3.11073 International Journal of Environment Vol.3(3 2014: 139-145

  20. Immunization with cholera toxin B subunit induces high-level protection in the suckling mouse model of cholera.

    Directory of Open Access Journals (Sweden)

    Gregory A Price

    Full Text Available Cholera toxin (CT is the primary virulence factor responsible for severe cholera. Vibrio cholerae strains unable to produce CT show severe attenuation of virulence in animals and humans. The pentameric B subunit of CT (CTB contains the immunodominant epitopes recognized by antibodies that neutralize CT. Although CTB is a potent immunogen and a promising protective vaccine antigen in animal models, immunization of humans with detoxified CT failed to protect against cholera. We recently demonstrated however that pups reared from mice immunized intraperitoneally (IP with 3 doses of recombinant CTB were well protected against a highly lethal challenge dose of V. cholerae N16961. The present study investigated how the route and number of immunizations with CTB could influence protective efficacy in the suckling mouse model of cholera. To this end female mice were immunized with CTB intranasally (IN, IP, and subcutaneously (SC. Serum and fecal extracts were analyzed for anti-CTB antibodies by quantitative ELISA, and pups born to immunized mothers were challenged orogastrically with a lethal dose of V. cholerae. Pups from all immunized groups were highly protected from death by 48 hours (64-100% survival. Cox regression showed that percent body weight loss at 24 hours predicted death by 48 hours, but we were unable to validate a specific amount of weight loss as a surrogate marker for protection. Although CTB was highly protective in all regimens, three parenteral immunizations showed trends toward higher survival and less weight loss at 24 hours post infection. These results demonstrate that immunization with CTB by any of several routes and dosing regimens can provide protection against live V. cholerae challenge in the suckling mouse model of cholera. Our data extend the results of previous studies and provide additional support for the inclusion of CTB in the development of a subunit vaccine against V. cholerae.

  1. Highlight: Pioneer of oral rehydration therapy visits IDRC's Asia ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Dr Cash is renowned for his pioneering work on oral rehydration therapy (ORT), a practical treatment for cholera and other diseases causing diarrheal dehydration. A visiting professor at the Public Health Foundation of India, Dr Cash is a senior lecturer on global health in the Department of Global Health and Population at ...

  2. Identification of genes involved in low aminoglycoside-induced SOS response in Vibrio cholerae: a role for transcription stalling and Mfd helicase.

    Science.gov (United States)

    Baharoglu, Zeynep; Babosan, Anamaria; Mazel, Didier

    2014-02-01

    Sub-inhibitory concentrations (sub-MIC) of antibiotics play a very important role in selection and development of resistances. Unlike Escherichia coli, Vibrio cholerae induces its SOS response in presence of sub-MIC aminoglycosides. A role for oxidized guanine residues was observed, but the mechanisms of this induction remained unclear. To select for V. cholerae mutants that do not induce low aminoglycoside-mediated SOS induction, we developed a genetic screen that renders induction of SOS lethal. We identified genes involved in this pathway using two strategies, inactivation by transposition and gene overexpression. Interestingly, we obtained mutants inactivated for the expression of proteins known to destabilize the RNA polymerase complex. Reconstruction of the corresponding mutants confirmed their specific involvement in induction of SOS by low aminoglycoside concentrations. We propose that DNA lesions formed on aminoglycoside treatment are repaired through the formation of single-stranded DNA intermediates, inducing SOS. Inactivation of functions that dislodge RNA polymerase leads to prolonged stalling on these lesions, which hampers SOS induction and repair and reduces viability under antibiotic stress. The importance of these mechanisms is illustrated by a reduction of aminoglycoside sub-MIC. Our results point to a central role for transcription blocking at DNA lesions in SOS induction, so far underestimated.

  3. Hydroclimatological And Anthropogenic Drivers For Cholera Spreading

    Science.gov (United States)

    Righetto, Lorenzo; Bertuzzo, Enrico; Mari, Lorenzo; Casagrandi, Renato; Gatto, Marino; Rinaldo, Andrea

    2010-05-01

    The nature of waterborne diseases, among which cholera has a prominent importance, calls for a better understanding of the link between epidemic spreading, water and climate. To this end, we have developed a framework which involves a network-based description of a river system, connected with local communities which act as nodes of the network. This has allowed us to produce consistent simulations of real case studies. More recent investigations comprise the evaluation of the spreading velocity of an epidemic wave by means of a reaction-diffusion modeling approach. In particular, we have found that both transport processes and epidemiological quantities, such as the basic reproduction number, have a crucial effect in controlling the spreading of the epidemics. We first developed a description of bacterial movement along the network driven by advection and diffusion; afterward, we have included the movement of human populations. This latter model allowed us to establish the conditions that can trigger epidemic waves that start from the coastal region, where bacteria are autochthonous, and travel inland. In particular, our findings suggest that even relatively low values of human diffusion can have the epidemic propagate upstream. The interaction between climate, hydrology and epidemic events is still much debated, since no clear correlation between climatologic and epidemiological phenomena has emerged so far. However, a spatial assessment of hydrological and epidemiological mechanisms could be crucial to understand the evolution of cholera outbreaks. In particular, a hotly debated topic is the understanding of the mechanisms that can generate patterns of cholera incidence that exhibit an intra-annual double peak, as frequently observed in endemic region such as Bangladesh. One of the possible explanations proposed in the literature is that spring droughts cause bacteria concentration in water to rise dramatically, triggering the first peak. On the other hand

  4. Removal of Cholera Toxin from Aqueous Solution by Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Jussi A. O. Meriluoto

    2012-06-01

    Full Text Available Cholera remains a serious health problem, especially in developing countries where basic hygiene standards are not met. The symptoms of cholera are caused by cholera toxin, an enterotoxin, which is produced by the bacterium Vibrio cholerae. We have recently shown that human probiotic bacteria are capable of removing cyanobacterial toxins from aqueous solutions. In the present study we investigate the ability of the human probiotic bacteria, Lactobacillus rhamnosus strain GG (ATCC 53103 and Bifidobacterium longum 46 (DSM 14583, to remove cholera toxin from solution in vitro. Lactobacillus rhamnosus strain GG and Bifidobacterium longum 46 were able to remove 68% and 59% of cholera toxin from aqueous solutions during 18 h of incubation at 37 °C, respectively. The effect was dependent on bacterial concentration and L. rhamnosus GG was more effective at lower bacterial concentrations. No significant effect on cholera toxin concentration was observed when nonviable bacteria or bacterial supernatant was used.

  5. Cholera outbreak in Senegal in 2005: was climate a factor?

    Directory of Open Access Journals (Sweden)

    Guillaume Constantin de Magny

    Full Text Available Cholera is an acute diarrheal illness caused by Vibrio cholerae and occurs as widespread epidemics in Africa. In 2005, there were 31,719 cholera cases, with 458 deaths in the Republic of Senegal. We retrospectively investigated the climate origin of the devastating floods in mid-August 2005, in the Dakar Region of Senegal and the subsequent outbreak of cholera along with the pattern of cholera outbreaks in three other regions of that country. We compared rainfall patterns between 2002 and 2005 and the relationship between the sea surface temperature (SST gradient in the tropical Atlantic Ocean and precipitation over Senegal for 2005. Results showed a specific pattern of rainfall throughout the Dakar region during August, 2005, and the associated rainfall anomaly coincided with an exacerbation of the cholera epidemic. Comparison of rainfall and epidemiological patterns revealed that the temporal dynamics of precipitation, which was abrupt and heavy, was presumably the determining factor. Analysis of the SST gradient showed that the Atlantic Ocean SST variability in 2005 differed from that of 2002 to 2004, a result of a prominent Atlantic meridional mode. The influence of this intense precipitation on cholera transmission over a densely populated and crowded region was detectable for both Dakar and Thiès, Senegal. Thus, high resolution rainfall forecasts at subseasonal time scales should provide a way forward for an early warning system in Africa for cholera and, thereby, trigger epidemic preparedness. Clearly, attention must be paid to both natural and human induced environmental factors to devise appropriate action to prevent cholera and other waterborne disease epidemics in the region.

  6. Cholera toxin can catalyze ADP-ribosylation of cytoskeletal proteins

    International Nuclear Information System (INIS)

    Kaslow, H.R.; Groppi, V.E.; Abood, M.E.; Bourne, H.R.

    1981-01-01

    Cholera toxin catalyzes transfer of radiolabel from [ 32 P]NAD + to several peptides in particulate preparations of human foreskin fibroblasts. Resolution of these peptides by two-dimensional gel electrophoresis allowed identification of two peptides of M/sub r/ = 42,000 and 52,000 as peptide subunits of a regulatory component of adenylate cyclase. The radiolabeling of another group of peptides (M/sub r/ = 50,000 to 65,000) suggested that cholera toxin could catalyze ADP-ribosylation of cytoskeletal proteins. This suggestion was confirmed by showing that incubation with cholera toxin and [ 32 P]NAD + caused radiolabeling of purified microtubule and intermediate filament proteins

  7. The Orphans of Cholera Morbus in Yucatan, 1833

    Directory of Open Access Journals (Sweden)

    Elsa Malvido

    2013-07-01

    Full Text Available This essay discusses the phenomenon of orphanhood which affected a large number of children after the cholera epidemic that struck Yucatan in July 1833. Moreover, it inquires into the fate of children whose parents died of cholera, the role played by kinship networks to provide them with shelter, and the influence of the Church and the State on the situation. Based on first hand sources, the author suggests that the orphanhood produced by cholera served as a pretext for economically and socially privileged groups to get hold of free labor force both for domestic service and hacienda work.

  8. Plasma and Mucosal Immunoglobulin M, Immunoglobulin A, and Immunoglobulin G Responses to the Vibrio cholerae O1 Protein Immunome in Adults With Cholera in Bangladesh.

    Science.gov (United States)

    Charles, Richelle C; Nakajima, Rie; Liang, Li; Jasinskas, Al; Berger, Amanda; Leung, Daniel T; Kelly, Meagan; Xu, Peng; Kovác, Pavol; Giffen, Samantha R; Harbison, James D; Chowdhury, Fahima; Khan, Ashraful I; Calderwood, Stephen B; Bhuiyan, Taufiqur Rahman; Harris, Jason B; Felgner, Philip L; Qadri, Firdausi; Ryan, Edward T

    2017-07-01

    Cholera is a severe dehydrating illness of humans caused by toxigenic strains of Vibrio cholerae O1 or O139. Identification of immunogenic V. cholerae antigens could lead to a better understanding of protective immunity in human cholera. We probed microarrays containing 3652 V. cholerae antigens with plasma and antibody-in-lymphocyte supernatant (ALS, a surrogate marker of mucosal immune responses) from patients with severe cholera caused by V. cholerae O1 in Bangladesh and age-, sex-, and ABO-matched Bangladeshi controls. We validated a subset of identified antigens using enzyme-linked immunosorbent assay. Overall, we identified 608 immunoreactive V. cholerae antigens in our screening, 59 of which had higher immunoreactivity in convalescent compared with acute-stage or healthy control samples (34 in plasma, 39 in mucosal ALS; 13 in both sample sets). Identified antigens included cholera toxin B and A subunits, V. cholerae O-specific polysaccharide and lipopolysaccharide, toxin coregulated pilus A, sialidase, hemolysin A, flagellins (FlaB, FlaC, and FlaD), phosphoenolpyruvate-protein phosphotransferase, and diaminobutyrate-2-oxoglutarate aminotransferase. This study is the first antibody profiling of the mucosal and systemic antibody responses to the nearly complete V. cholerae O1 protein immunome; it has identified antigens that may aid in the development of an improved cholera vaccine. © The Author 2017. Published by Oxford University Press for the Infectious Diseases Society of America.

  9. Cholera in pregnancy: outcomes from a specialized cholera treatment unit for pregnant women in Léogâne, Haiti.

    Science.gov (United States)

    Ciglenecki, Iza; Bichet, Mathieu; Tena, Javier; Mondesir, Erneau; Bastard, Mathieu; Tran, Nguyen-Toan; Antierens, Annick; Staderini, Nelly

    2013-01-01

    The association between cholera in pregnancy and negative fetal outcome has been described since the 19(th) century. However, there is limited published literature on the subject. We describe pregnancy outcomes from a specialized multidisciplinary hospital unit at the onset of a large cholera outbreak in Haiti in 2010 and 2011. Pregnant women with cholera were hospitalized in a specialized unit within the MSF hospital compound in Léogâne and treated using standard cholera treatment guidelines but with earlier, more intense fluid replacement. All women had intravenous access established at admission regardless of their hydration status, and all received antibiotic treatment. Data were collected on patient demographics, pregnancy and cholera status, and pregnancy outcome. In this analysis we calculated risk ratios for fetal death and performed logistic regression analysis to control for confounding factors. 263 pregnant women with cholera were hospitalized between December 2010 and July 2011. None died during hospitalization, 226 (86%) were discharged with a preserved pregnancy and 16 (6%) had live fullterm singleton births, of whom 2 died within the first 5 days postpartum. The remaining 21 pregnancies (8%) resulted in intrauterine fetal death. The risk of fetal death was associated with factors reflecting severity of the cholera episode: after adjusting for confounding factors, the strongest risk factor for fetal death was severe maternal dehydration (adjusted risk ratio for severe vs. mild dehydration was 9.4, 95% CI 2.5-35.3, p = 0.005), followed by severe vomiting (adjusted risk ratio 5.1, 95% 1.1-23.8, p = 0.041). This is the largest cohort of pregnant women with cholera described to date. The main risk factor identified for fetal death was severity of dehydration. Our experience suggests that establishing specialized multidisciplinary units which facilitate close follow-up of both pregnancy and dehydration status due to cholera could be beneficial

  10. Pathogen inactivation techniques.

    Science.gov (United States)

    Pelletier, J P R; Transue, S; Snyder, E L

    2006-01-01

    The desire to rid the blood supply of pathogens of all types has led to the development of many technologies aimed at the same goal--eradication of the pathogen(s) without harming the blood cells or generating toxic chemical agents. This is a very ambitious goal, and one that has yet to be achieved. One approach is to shun the 'one size fits all' concept and to target pathogen-reduction agents at the Individual component types. This permits the development of technologies that might be compatible with, for example, plasma products but that would be cytocidal and thus incompatible with platelet concentrates or red blood cell units. The technologies to be discussed include solvent detergent and methylene blue treatments--designed to inactivate plasma components and derivatives; psoralens (S-59--amotosalen) designed to pathogen-reduce units of platelets; and two products aimed at red blood cells, S-303 (a Frale--frangible anchor-linker effector compound) and Inactine (a binary ethyleneimine). A final pathogen-reduction material that might actually allow one material to inactivate all three blood components--riboflavin (vitamin B2)--is also under development. The sites of action of the amotosalen (S-59), the S-303 Frale, Inactine, and riboflavin are all localized in the nucleic acid part of the pathogen. Solvent detergent materials act by dissolving the plasma envelope, thus compromising the integrity of the pathogen membrane and rendering it non-infectious. By disrupting the pathogen's ability to replicate or survive, its infectivity is removed. The degree to which bacteria and viruses are affected by a particular pathogen-reducing technology relates to its Gram-positive or Gram-negative status, to the sporulation characteristics for bacteria, and the presence of lipid or protein envelopes for viruses. Concerns related to photoproducts and other breakdown products of these technologies remain, and the toxicology of pathogen-reduction treatments is a major ongoing area

  11. Free radical inactivation of trypsin

    International Nuclear Information System (INIS)

    Cudina, Ivana; Jovanovic, S.V.

    1988-01-01

    Reactivities of free radical oxidants, radical OH, Br2-anion radical and Cl 3 COO radical and a reductant, CO2-anion radical, with trypsin and reactive protein components were determined by pulse radiolysis of aqueous solutions at pH 7, 20 0 C. Highly reactive free radicals, radical OH, Br2-anion radical and CO2-anion radical, react with trypsin at diffusion controlled rates. Moderately reactive trichloroperoxy radical, k(Cl 3 COO radical + trypsin) preferentially oxidizes histidine residues. The efficiency of inactivation of trypsin by free radicals is inversely proportional to their reactivity. The yields of inactivation of trypsin by radical OH, Br2-anion radical and CO2-anion radical are low, G(inactivation) = 0.6-0.8, which corresponds to ∼ 10% of the initially produced radicals. In contrast, Cl 3 COO radical inactivates trypsin with ∼ 50% efficiency, i.e. G(inactivation) = 3.2. (author)

  12. X-ray inactivation and reactivation characteristics of the phage 'kappa'

    International Nuclear Information System (INIS)

    Bhattacharyya, S.C.; Samad, S.A.; Mandal, J.C.; Chatterjee, S.N.

    1991-01-01

    Vibrio cholerae temperate phage 'kappa' was inactivated by X-ray (60 kV) in a dose dependent manner, the inactivation dose leading to 37% survival (D 37 ) in PBS, pH 7.4 being 0.36 kGy. The phages were significantly protected against X-ray irradiation when histidine or cysteine or both were present in PBS or when phages were irradiated in nutrient broth. The maximum protection was offered when histidine (10.0 nM) and cysteine (10.0 nM) were both present in PBS (dose enhancement factor being 4.17). The X-irradiated 'kappa' phages also underwent a small but significant Weigle reactivation and also Weigle mutagenesis in the UV-irradiated V. cholerae host H218Sm r . The Weigle factor (WF) or the frequency of clear plaque mutants increased with increasing UV dose, attained a maximum at the UV dose of 2.4 Jm -2 and thereafter decreased gradually with further increase of UV dose. The X-ray dose (D)-survival (S) curves could be empirically described by the equation S=exp-(aD+bD 2 ) where 'a' and 'b' are constants depending on the irradiation conditions and good agreement between the theoretical curves and experimental data was obtained. (author). 1 5 refs., 2 fig., 1 tab

  13. ANTAGONISM AGAINST VIBRIO CHOLERAE BY BACTERIAL DIFFUSIBLE COMPOUND IN THE FECAL MICROBIOTA OF RODENTS

    Directory of Open Access Journals (Sweden)

    Silva Simone Helena da

    1998-01-01

    Full Text Available In an ex vivo agar plate assay, we monitored the appearance of an inhibitory halo against Vibrio cholerae from the feces of Wistar and Fischer rats aged 10 to 42 days. The frequency of Wistar rats showing halo increased from 0% (10 days to a maximum of 80.0% (29 days and then decreased to 53.3% (42 days. A similar pattern was obtained with Fischer rats but with a lower intensity (maximum frequency of 50.0% by day 36. In a separate experiment, when Wistar rats were fed a low-protein diet for 7 days, the inhibitory halo decreased drastically. Three apparently different colony morphologies were isolated from the dominant fecal microbiota: a facultative anaerobe (FAN and two strict anaerobes (SAN. The ex vivo inhibitory test showed a halo around the feces of germfree mice monoassociated with the FAN bacterium or one of the SAN bacterium but not of the germfree ones. After oral challenge of all groups with V. cholerae, a permissive and a drastic barrier effects were observed in mice with FAN and SAN associated bacteria, respectively. The FAN and one SAN bacteria used in the in vivo challenges were identified as Escherichia coli and Streptococcus intermedius, respectively. The potent antagonism developed by the rat intestinal microbiota against V. cholerae seems to be due, in part, to diffusible compounds and this phenomenon depends apparently on age, strain and nutrition of the animals. These preliminary results also suggest that this effect was due to more than one bacterial component at any given moment.

  14. Inactivation of Microorganisms

    Science.gov (United States)

    Alzamora, Stella Maris; Guerrero, Sandra N.; Schenk, Marcela; Raffellini, Silvia; López-Malo, Aurelio

    Minimal processing techniques for food preservation allow better retention of product flavor, texture, color, and nutrient content than comparable conventional treatments. A wide range of novel alternative physical factors have been intensely investigated in the last two decades. These physical factors can cause inactivation of microorganisms at ambient or sublethal temperatures (e.g., high hydrostatic pressure, pulsed electric fields, ultrasound, pulsed light, and ultraviolet light). These technologies have been reported to reduce microorganism population in foods while avoiding the deleterious effects of severe heating on quality. Among technologies, high-energy ultrasound (i.e., intensities higher than 1 W/cm2, frequencies between 18 and 100 kHz) has attracted considerable interest for food preservation applications (Mason et al., 1996; Povey and Mason, 1998).

  15. Mean inactivation dose (D)

    International Nuclear Information System (INIS)

    Vijayakumar, S.; Ng, T.C.; Raudkivi, U.; Meaney, T.J.

    1990-01-01

    By predicting treatment outcome to radiotherapy from in vitro radiobiological parameters, not only individual patient treatments can be tailored, but also new promising treatment protocols can be tried in patients in whom unfavorable outcome is predicted. In this respect, choosing the right parameter can be very important. Unlike D 0 and N which provide information of the distal part of the survival curve, mean inactivation dose (D) estimates overall radiosensitivity. However, the parameters reflecting the response at the clinically relevant low-dose region are neglected in the literature. In a literature survey of 98 papers in which survival curves or D 0 /N were used, only in 2 D was used. In 21 papers the D 0 /n values were important in drawing conclusions. By calculating D in 3 of these 21 papers, we show that the conclusion drawn may be altered with the use of D. The importance of ''low-dose-region-parameters'' is reviewed. (orig.)

  16. Rapid and scalable plant-based production of a cholera toxin B subunit variant to aid in mass vaccination against cholera outbreaks.

    Directory of Open Access Journals (Sweden)

    Krystal Teasley Hamorsky

    Full Text Available INTRODUCTION: Cholera toxin B subunit (CTB is a component of an internationally licensed oral cholera vaccine. The protein induces neutralizing antibodies against the holotoxin, the virulence factor responsible for severe diarrhea. A field clinical trial has suggested that the addition of CTB to killed whole-cell bacteria provides superior short-term protection to whole-cell-only vaccines; however, challenges in CTB biomanufacturing (i.e., cost and scale hamper its implementation to mass vaccination in developing countries. To provide a potential solution to this issue, we developed a rapid, robust, and scalable CTB production system in plants. METHODOLOGY/PRINCIPAL FINDINGS: In a preliminary study of expressing original CTB in transgenic Nicotiana benthamiana, the protein was N-glycosylated with plant-specific glycans. Thus, an aglycosylated CTB variant (pCTB was created and overexpressed via a plant virus vector. Upon additional transgene engineering for retention in the endoplasmic reticulum and optimization of a secretory signal, the yield of pCTB was dramatically improved, reaching >1 g per kg of fresh leaf material. The protein was efficiently purified by simple two-step chromatography. The GM1-ganglioside binding capacity and conformational stability of pCTB were virtually identical to the bacteria-derived original B subunit, as demonstrated in competitive enzyme-linked immunosorbent assay, surface plasmon resonance, and fluorescence-based thermal shift assay. Mammalian cell surface-binding was corroborated by immunofluorescence and flow cytometry. pCTB exhibited strong oral immunogenicity in mice, inducing significant levels of CTB-specific intestinal antibodies that persisted over 6 months. Moreover, these antibodies effectively neutralized the cholera holotoxin in vitro. CONCLUSIONS/SIGNIFICANCE: Taken together, these results demonstrated that pCTB has robust producibility in Nicotiana plants and retains most, if not all, of major

  17. Cholera toxin expression by El Tor Vibrio cholerae in shallow culture growth conditions.

    Science.gov (United States)

    Cobaxin, Mayra; Martínez, Haydee; Ayala, Guadalupe; Holmgren, Jan; Sjöling, Asa; Sánchez, Joaquín

    2014-01-01

    Vibrio cholerae O1 classical, El Tor and O139 are the primary biotypes that cause epidemic cholera, and they also express cholera toxin (CT). Although classical V. cholerae produces CT in various settings, the El Tor and O139 strains require specific growth conditions for CT induction, such as the so-called AKI conditions, which consist of growth in static conditions followed by growth under aerobic shaking conditions. However, our group has demonstrated that CT production may also take place in shallow static cultures. How these type of cultures induce CT production has been unclear, but we now report that in shallow culture growth conditions, there is virtual depletion of dissolved oxygen after 2.5 h of growth. Concurrently, during the first three to 4 h, endogenous CO2 accumulates in the media and the pH decreases. These findings may explain CT expression at the molecular level because CT production relies on a regulatory cascade, in which the key regulator AphB may be activated by anaerobiosis and by low pH. AphB activation stimulates TcpP synthesis, which induces ToxT production, and ToxT directly stimulates ctxAB expression, which encodes CT. Importantly, ToxT activity is enhanced by bicarbonate. Therefore, we suggest that in shallow cultures, AphB is activated by initial decreases in oxygen and pH, and subsequently, ToxT is activated by intracellular bicarbonate that has been generated from endogenous CO2. This working model would explain CT production in shallow cultures and, possibly, also in other growth conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Assessment of Risk of Cholera in Haiti following Hurricane Matthew.

    Science.gov (United States)

    Khan, Rakib; Anwar, Rifat; Akanda, Shafqat; McDonald, Michael D; Huq, Anwar; Jutla, Antarpreet; Colwell, Rita

    2017-09-01

    Damage to the inferior and fragile water and sanitation infrastructure of Haiti after Hurricane Matthew has created an urgent public health emergency in terms of likelihood of cholera occurring in the human population. Using satellite-derived data on precipitation, gridded air temperature, and hurricane path and with information on water and sanitation (WASH) infrastructure, we tracked changing environmental conditions conducive for growth of pathogenic vibrios. Based on these data, we predicted and validated the likelihood of cholera cases occurring past hurricane. The risk of cholera in the southwestern part of Haiti remained relatively high since November 2016 to the present. Findings of this study provide a contemporary process for monitoring ground conditions that can guide public health intervention to control cholera in human population by providing access to vaccines, safe WASH facilities. Assuming current social and behavioral patterns remain constant, it is recommended that WASH infrastructure should be improved and considered a priority especially before 2017 rainy season.

  19. Cholera in Haiti: Reproductive numbers and vaccination coverage estimates

    Science.gov (United States)

    Mukandavire, Zindoga; Smith, David L.; Morris, J. Glenn, Jr.

    2013-01-01

    Cholera reappeared in Haiti in October, 2010 after decades of absence. Cases were first detected in Artibonite region and in the ensuing months the disease spread to every department in the country. The rate of increase in the number of cases at the start of epidemics provides valuable information about the basic reproductive number (). Quantitative analysis of such data gives useful information for planning and evaluating disease control interventions, including vaccination. Using a mathematical model, we fitted data on the cumulative number of reported hospitalized cholera cases in Haiti. varied by department, ranging from 1.06 to 2.63. At a national level, 46% vaccination coverage would result in an () cholera vaccines in endemic and non-endemic regions, our results suggest that moderate cholera vaccine coverage would be an important element of disease control in Haiti.

  20. Detection and confirmation of toxigenic Vibrio cholerae O1 in ...

    African Journals Online (AJOL)

    2013-08-20

    Aug 20, 2013 ... mental water samples, as well as for confirmation of clinical isolates. Keywords: ... Monitoring the presence of V. cholerae in drinking water sources ... have several advantages: they are rapid, sensitive, highly selective and do ...

  1. Cholera after the consumption of raw oysters. A case report.

    Science.gov (United States)

    Klontz, K C; Tauxe, R V; Cook, W L; Riley, W H; Wachsmuth, I K

    1987-12-01

    In August 1986, a 76-year-old woman in Miami, Florida, developed profuse watery diarrhea and abdominal cramps. Two and four days before the onset of her illness, she had eaten six raw oysters at each of two restaurants in Miami. A stool specimen yielded toxigenic Vibrio cholerae O1 biotype El Tor, serotype Inaba. The results of toxin gene probing of the organism recovered from the patient differed significantly from those of other V. cholerae O1 isolates from the Gulf Coast and elsewhere in the world. A program of active surveillance identified no other cases of cholera in Miami. The source of the raw oysters eaten by the patient was traced to Louisiana. Her case represents the first reported case of cholera associated with eating raw oysters.

  2. Successful Multi-partner Response to a Cholera Outbreak

    African Journals Online (AJOL)

    46987.2

    World Health Organisation,. Country Office ... a global threat to public health and a key indicator of inadequate .... While the cholera outbreak in Lusaka was first reported in. Kanyama ... restaurants, markets, schools and other public places of.

  3. Co-variation of Cholera with Climatic and Environmental Parameters ...

    African Journals Online (AJOL)

    adjusted cholera cases and coastal ocean chlorophyll a and, to some degree, sea surface temperature, the ... environmental variables, such as air and water temperature, rainfall ... nutrients and plankton biomass (Vezulli et al., 2010). Water ...

  4. 7. Factors Associated With the Recurring Cholera Outbreaks in ...

    African Journals Online (AJOL)

    46987.2

    analysis was performed to control for confounders. Results:There was a ..... their household, however, the sewer system, flush/pour ... and environmental data from cholera-endemic areas of Zanzibar .... food served on an international aircraft,.

  5. Hydroclimatic Extremes and Cholera Dynamics in the 21st Century

    Science.gov (United States)

    Akanda, A. S.; Jutla, A. S.; Islam, S.

    2012-12-01

    Cholera, an acute water-borne diarrheal illness, has reemerged as a significant health threat across much of the developing world. Despite major advances in the ecological and the microbiological understanding of the causative agent, V. cholerae, the role of the underlying climatic and environmental processes in propagating transmission is not adequately understood. Recent findings suggest a more prominent role of hydroclimatic extremes - droughts and floods - on the unique dual cholera peaks in the Bengal Delta region of South Asia, the native homeland of cholera. Increasing water scarcity and abundance, and coastal sea-level rise, influenced by changing climate patterns and large-scale climatic phenomena, is likely to adversely impact cholera transmission in South Asia. We focus on understanding how associated changes in macro-scale conditions in this region will impact micro-scale processes related to cholera in coming decades. We use the PRECIS Regional Climate Model over the Ganges-Brahmaputra-Meghna (GBM) basin region to simulate detailed high resolution projections of climate patterns for the 21st century. Precipitation outputs are analyzed for the 1980-2040 period to identify the trends and changes in hydroclimatic extremes and potential impacts on cholera dynamics over the next three decades (2010-2040), in relation to the cholera surveillance operations over the past three decades (1980-2010). We find that an increased number of extreme precipitation events with prolonged dry periods in the Ganges basin region will likely adversely affect dry season cholera outbreaks. Increased monsoon precipitation volumes in the Brahmaputra basin catchments are likely to cause record floods and subsequently trigger large epidemics in downstream areas. Our results provide new insight by identifying the changes in the two distinctly different, pre and post monsoon, cholera transmission mechanisms related to large-scale climatic controls that prevail in the region. A

  6. Response to the cholera outbreak in South Sudan

    African Journals Online (AJOL)

    On Thursday, May 15th 2014, the Ministry of Health (MoH) of the Republic of South Sudan declared a cholera outbreak in the capital Juba. As we go to press, the cholera has spread to other parts of the country and the cases are increasing. In its press statement, the MoH said it had “Reactivated a national emergency ...

  7. Community health facility preparedness for a cholera surge in Haiti.

    Science.gov (United States)

    Mobula, Linda Meta; Jacquet, Gabrielle A; Weinhauer, Kristin; Alcidas, Gladys; Thomas, Hans-Muller; Burnham, Gilbert

    2013-01-01

    With increasing population displacement and worsening water insecurity after the 2010 earthquake, Haiti experienced a large cholera outbreak. Our goal was to evaluate the strengths and weaknesses of seven community health facilities' ability to respond to a surge in cholera cases. Since 2010, Catholic Relief Services (CRS) with a number of public and private donors has been working with seven health facilities in an effort to reduce morbidity and mortality from cholera infection. In November 2012, CRS through the Centers for Disease Control and Prevention (CDC)'s support, asked the Johns Hopkins Center for Refugee and Disaster Response to conduct a cholera surge simulation tabletop exercise at these health facilities to improve each facility's response in the event of a cholera surge. Using simulation development guidelines from the Pan American Health Organization and others, a simulation scenario script was produced that included situations of differing severity, supply chain, as well as a surge of patients. A total of 119 hospital staff from seven sites participated in the simulation exercise including community health workers, clinicians, managers, pharmacists, cleaners, and security guards. Clinics that had challenges during the simulated clinical care of patients were those that did not appropriately treat all cholera patients according to protocol, particularly those that were vulnerable, those that would need additional staff to properly treat patients during a surge of cholera, and those that required a better inventory of supplies. Simulation-based activities have the potential to identify healthcare delivery system vulnerabilities that are amenable to intervention prior to a cholera surge.

  8. The repertoire of glycosphingolipids recognized by Vibrio cholerae.

    Directory of Open Access Journals (Sweden)

    John Benktander

    Full Text Available The binding of cholera toxin to the ganglioside GM1 as the initial step in the process leading to diarrhea is nowadays textbook knowledge. In contrast, the knowledge about the mechanisms for attachment of Vibrio cholerae bacterial cells to the intestinal epithelium is limited. In order to clarify this issue, a large number of glycosphingolipid mixtures were screened for binding of El Tor V. cholerae. Several specific interactions with minor complex non-acid glycosphingolipids were thereby detected. After isolation of binding-active glycosphingolipids, characterization by mass spectrometry and proton NMR, and comparative binding studies, three distinct glycosphingolipid binding patterns were defined. Firstly, V. cholerae bound to complex lacto/neolacto glycosphingolipids with the GlcNAcβ3Galβ4GlcNAc sequence as the minimal binding epitope. Secondly, glycosphingolipids with a terminal Galα3Galα3Gal moiety were recognized, and the third specificity was the binding to lactosylceramide and related compounds. V. cholerae binding to lacto/neolacto glycosphingolipids, and to the other classes of binding-active compounds, remained after deletion of the chitin binding protein GbpA. Thus, the binding of V. cholerae to chitin and to lacto/neolacto containing glycosphingolipids represents two separate binding specificities.

  9. Antimicrobial Resistance Risks of Cholera Prophylaxis for United Nations Peacekeepers.

    Science.gov (United States)

    Kunkel, Amber; Lewnard, Joseph A; Pitzer, Virginia E; Cohen, Ted

    2017-08-01

    More than 5 years after a United Nations peacekeeping battalion introduced cholera to Haiti, over 150,000 peacekeepers continue to be deployed annually from countries where cholera is endemic. The United Nations has thus far declined to provide antimicrobial chemoprophylaxis to peacekeepers, a policy based largely on concerns that the risks of drug resistance generation and spread would outweigh the potential benefits of preventing future cholera importations. In this study, we sought to better understand the relative benefits and risks of cholera chemoprophylaxis for peacekeepers in terms of antibiotic resistance. Using a stochastic model to quantify the potential impact of chemoprophylaxis on importation and transmission of drug-resistant and drug-sensitive Vibrio cholerae , we found that chemoprophylaxis would decrease the probability of cholera importation but would increase the expected number of drug-resistant infections if an importation event were to occur. Despite this potential increase, we found that at least 10 drug-sensitive infections would likely be averted per excess drug-resistant infection under a wide range of assumptions about the underlying prevalence of drug resistance and risk of acquired resistance. Given these findings, policymakers should reconsider whether the potential resistance risks of providing antimicrobial chemoprophylaxis to peacekeepers are sufficient to outweigh the anticipated benefits. Copyright © 2017 American Society for Microbiology.

  10. Distribution ofVibrio cholerae in two Florida estuaries.

    Science.gov (United States)

    Hood, M A; Ness, G E; Rodrick, G E; Blake, N J

    1983-04-01

    The distribution ofVibrio cholerae was examined in 2 Florida estuaries, Apalachicola and Tampa Bay.Vibrio cholerae serotype non-01 was the most abundant serotype, being isolated from 45% of the oyster samples, 30% of the sediments, 50% of the waters, and 75% of the blue crabs.Vibrio cholerae serotype 01 was isolated from only one oyster sample. Strong linear correlations betweenV. cholerae and temperature, salinity, or the other physical/chemical parameters measured,Escherichia coli, or fecal coliforms were not observed, but a range of temperatures and salinities appeared relevant to the distribution of the organism. The organism was present in the highest concentrations when salinities were 10‰-25‰ and temperatures were 20‡C-35‡C.In vitro growth curves of 95V. cholerae environmental isolates further supported that 10‰-25‰ was an ideal salinity range for the organisms. The results suggest thatV. cholerae is a widely distributed organism in the nutrient-rich warm waters of the Gulf Coast estuaries.

  11. Epidemiology, determinants and dynamics of cholera in pakistan: gaps and prospects for future research

    International Nuclear Information System (INIS)

    Naseer, M.; Jamali, T.

    2014-01-01

    Cholera is one of the notifiable endemic diseases in Pakistan, but the reporting of cholera cases is still unsatisfactory. Most of the diagnosed cases are never reported to the relevant authorities. In the year 1993 - 2005, the country did not report any single case of cholera to the WHO. The objectives of this review were to understand the epidemiology and to identify the possible determinants of cholera infection in Pakistan. Medscape, Medline, PakMedinet and PubMed, was searched, using key words, epidemiology and determinants of cholera infection in Pakistan during 1995 - 2010. Morbidity and mortality due to cholera infection during 1995 - 2010, without any language restriction. Out of 27 articles published between 1995 - 2010, 17 articles were included in the review. Vibrio cholerae O139 identified as a major cause of infection in older age group, while O1 biotype of cholera as a predominant cause of cholera among young individuals. Mainly reported determinants of cholera in Pakistan include poor sanitation and hygiene practices, increased population density in urban areas, leading to rapid and unplanned urbanization of the major cities and climate change due to increased environmental pollution in Pakistan are plausible factors for endemicity of cholera in Pakistan. Cholera reporting as a notifiable disease to the relevant departments and timely action can prevent the risk of outbreaks. There is a need to identify specific behavioral and environmental determinants responsible for outbreaks and epidemics of cholera in Pakistan which can help to design appropriate preventive and control interventions. (author)

  12. Elevation and cholera: an epidemiological spatial analysis of the cholera epidemic in Harare, Zimbabwe, 2008-2009

    Directory of Open Access Journals (Sweden)

    Luque Fernandez Miguel A

    2012-06-01

    Full Text Available Abstract Background In highly populated African urban areas where access to clean water is a challenge, water source contamination is one of the most cited risk factors in a cholera epidemic. During the rainy season, where there is either no sewage disposal or working sewer system, runoff of rains follows the slopes and gets into the lower parts of towns where shallow wells could easily become contaminated by excretes. In cholera endemic areas, spatial information about topographical elevation could help to guide preventive interventions. This study aims to analyze the association between topographic elevation and the distribution of cholera cases in Harare during the cholera epidemic in 2008 and 2009. Methods We developed an ecological study using secondary data. First, we described attack rates by suburb and then calculated rate ratios using whole Harare as reference. We illustrated the average elevation and cholera cases by suburbs using geographical information. Finally, we estimated a generalized linear mixed model (under the assumption of a Poisson distribution with an Empirical Bayesian approach to model the relation between the risk of cholera and the elevation in meters in Harare. We used a random intercept to allow for spatial correlation of neighboring suburbs. Results This study identifies a spatial pattern of the distribution of cholera cases in the Harare epidemic, characterized by a lower cholera risk in the highest elevation suburbs of Harare. The generalized linear mixed model showed that for each 100 meters of increase in the topographical elevation, the cholera risk was 30% lower with a rate ratio of 0.70 (95% confidence interval=0.66-0.76. Sensitivity analysis confirmed the risk reduction with an overall estimate of the rate ratio between 20% and 40%. Conclusion This study highlights the importance of considering topographical elevation as a geographical and environmental risk factor in order to plan cholera preventive

  13. [Performance of Cholera-SMART and Pathogen-Detection-Kit in the quick diagnosis of cholera].

    Science.gov (United States)

    Bolaños, Hilda María; Acuña, María Teresa; Serrano, Ana María; Obando, Xinia; Mairena, Hazel; Cháves, Lorena; Sandí, Flor; Rodríguez, Gina; Tamplin, Mark L; Pérez, Enrique; Campos, Elena

    2004-10-01

    To compare the performance of two rapid systems for the diagnosis of cholera with the culture method, and to propose a strategy for improving the specificity and sensitivity of these systems and reducing the costs involved in making a diagnosis. The following institutions participated in the study: the National Bacteriology Referral Center (Centro Nacional de Referencia en Bacteriologia, CNRB) of the Costa Rican Institute for Research and Teaching in Nutrition and Health (Instituto Costarricense de Investigacion y Ensenanza en Nutricion y Salud, INCIENSA) and various hospitals in the provinces of Alajuela, Guanacaste and San Jose, in Costa Rica. A total of 237 feces samples were used to asses the performance of two tests for the rapid detection of Vibrio cholerae 01: the Pathogen Detection Kit (PDK, Intelligent Monitoring Systems, Gainesville, Florida, USA) and Cholera-SMART (New Horizons Diagnostics Corp., Columbia, Maryland, USA), both when applied directly (direct SMART and direct PDK) and when applied to specimens cultured in broth-enriched medium for 6 hours (SMART-6 and CPK-6) and for 18 hours (SMART-18 and PDK-18) at 37 degrees C in alkaline peptone water. Liquid and partially formed stools were cultured and examined by means of the rapid direct test; when the initial result was negative, the tests were repeated after culture for periods of 6 and 18 hours. Rectal and fecal swabs were obtained from feces cultured in enriched-broth medium for 6 and 18 hours. In addition, we studied the sensitivity of the rapid testing systems by using pure cultures of V. cholerae 01 (strain SOS-833, CNRB, Costa Rica) that were incubated for 18 to 24 hours, and we assessed the usefulness of observing motility under the microscope in order to rationalize the use of rapid methods. The sensitivity of the direct SMART test and of the direct PDK test was 100% when samples obtained from liquid and partially formed stools and from the intestinal contents of dead bodies were used. With

  14. Cholera Outbreaks in Urban Bangladesh In 2011.

    Science.gov (United States)

    Haque, Farhana; Hossain, M Jahangir; Kundu, Subodh Kumar; Naser, Abu Mohd; Rahman, Mahmudur; Luby, Stephen P

    In 2011, a multidisciplinary team investigated two diarrhoea outbreaks affecting urban Bangladeshi communities from the districts of Bogra and Kishorganj to identify etiology, pathways of transmission, and factors contributing to these outbreaks. We defined case-patients with severe diarrhoea as residents from affected communities admitted with ≥3 loose stools per day. We listed case-patients, interviewed and examined them, and collected rectal swabs. We visited the affected communities to explore the water and sanitation infrastructure. We tested the microbial load of water samples from selected case household taps, tube wells, and pump stations. We conducted anthropological investigations to understand community perceptions regarding the outbreaks. We identified 21 case-patients from Bogra and 84 from Kishorganj. The median age in Bogra was 23 years, and 21 years in Kishorganj. There were no reported deaths. We isolated Vibrio in 29% (5/17) of rectal swabs from Bogra and in 40% (8/20) from Kishorganj. We found Vibrio in 1/8 tap water samples from Bogra and in both of the samples from Kishorganj. We did not find Vibrio in water samples from pumps or tube wells in either outbreak. Ground water extracted through deep tube wells was supplied intermittently through interconnected pipes without treatment in both areas. We found leakages in the water pipes in Bogra, and in Kishorganj water pipes passed through open sewers. The rapid onset of severe diarrhoea predominantly affecting adults and the isolation of cholera in rectal swabs confirmed that these outbreaks were caused by Vibrio cholerae . The detection of Vibrio in water samples organisms from taps but not from pumps or tube wells, suggested contamination within the pipes. Safe water provision is difficult in municipalities where supply is intermittent, and where pipes commonly leak. Research to develop and evaluate water purification strategies could identify appropriate approaches for ensuring safe drinking

  15. Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country.

    Science.gov (United States)

    Boucher, Yan

    2016-05-03

    Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15). It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae. Copyright © 2016 Boucher.

  16. Sustained Local Diversity of Vibrio cholerae O1 Biotypes in a Previously Cholera-Free Country

    Directory of Open Access Journals (Sweden)

    Yan Boucher

    2016-07-01

    Full Text Available Although the current cholera pandemic can trace its origin to a specific time and place, many variants of Vibrio cholerae have caused this disease over the last 50 years. The relative clinical importance and geographical distribution of these variants have changed with time, but most remain in circulation. Some countries, such as Mexico and Haiti, had escaped the current pandemic, until large epidemics struck them in 1991 and 2010, respectively. Cholera has been endemic in these countries ever since. A recent retrospective study in mBio presents the results of more than 3 decades of V. cholerae monitoring from environmental and clinical sources in Mexico (S. Y. Choi et al., mBio 7:e02160-15, 2016, http://dx.doi.org/10.1128/mBio.02160-15. It reveals that multiple V. cholerae variants, including classical strains from the previous pandemic, as well as completely novel biotypes, have been circulating in Mexico. This discovery has important implications for the epidemiology and evolution of V. cholerae.

  17. Breast milk reduces the risk of illness in children of mothers with cholera

    DEFF Research Database (Denmark)

    Qureshi, Katja; Mølbak, Kåre; Sandström, Anita

    2006-01-01

    BACKGROUND: A protective effect of breastfeeding against cholera has been demonstrated in areas endemic of cholera. To assess the protection offered by breast milk from mothers living in an area that had been free from cholera for 7 years, we investigated mothers with cholera and their children...... during an epidemic with Vibrio cholerae El Tor in the capital of Guinea-Bissau. METHODS: Eighty mothers with clinical cholera and their children were identified, and interviewed. Blood samples for vibriocidal and antitoxin antibodies were collected from mother-and-child pairs. Breast milk samples were...... collected from lactating mothers.Cholera was defined as acute watery diarrhea during the epidemic and a vibriocidal reciprocal titer of 20 or above. RESULTS: Three (7%) of 42 breastfed children had cholera as defined above compared with 9 (24%) of 38 nonbreastfed children (RR for breastfed children, 0...

  18. Uptake of Vibrio cholerae biotype eltor from contaminated water by water hyacinth (eichornia crassipes).

    Science.gov (United States)

    Spira, W M; Huq, A; Ahmed, Q S; Saeed, Y A

    1981-09-01

    Vibrio cholerae biotype eltor appears to concentrate on the surface of the water hyacinth (Eichornia crassipes), thereby enhancing its survival and its potential for transmission through waterways of cholera-endemic regions such as Bangladesh.

  19. Uptake of Vibrio cholerae Biotype eltor from Contaminated Water by Water Hyacinth (Eichornia crassipes)

    OpenAIRE

    Spira, William M.; Huq, Anwarul; Ahmed, Qazi Shafi; Saeed, Yusuf A.

    1981-01-01

    Vibrio cholerae biotype eltor appears to concentrate on the surface of the water hyacinth (Eichornia crassipes), thereby enhancing its survival and its potential for transmission through waterways of cholera-endemic regions such as Bangladesh.

  20. A novel kit for rapid detection of Vibrio cholerae O1.

    Science.gov (United States)

    Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

    1994-01-01

    We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bacterial strains, including both O1 and non-O1 serotypes of V. cholerae isolated from samples collected from a variety of geographical regions, were tested, and positive reactions were observed only with V. cholerae O1. Also, results of a field trial in Bangladesh, employing Cholera SMART, showed 100% specificity and 96% sensitivity compared with conventional culture methods. Another field trial, in Mexico, showed that Cholera SMART was 100% in agreement with a recently described coagglutination test when 108 stool specimens were tested.

  1. Prevalence of Vibrio cholerae O1 serogroup in Assam, India: A hospital-based study

    Directory of Open Access Journals (Sweden)

    Ajanta Sharma

    2017-01-01

    Interpretation & conclusions: Emergence of resistance amongst V. cholerae towards many antibiotics is a matter of concern. Hence, continuous surveillance for diarrhoeal disorders is necessary to control the future outbreaks of cholera in this region.

  2. A novel kit for rapid detection of Vibrio cholerae O1.

    OpenAIRE

    Hasan, J A; Huq, A; Tamplin, M L; Siebeling, R J; Colwell, R R

    1994-01-01

    We report on the development and testing of a novel, rapid, colorimetric immunodiagnostic kit, Cholera SMART, for direct detection of the presence of Vibrio cholerae O1 in clinical specimens. Unlike conventional culture methods requiring several days to complete, the Cholera SMART kit can be used directly in the field by untrained or minimally skilled personnel to detect V. cholerae O1 in less than 15 min, without cumbersome laboratory equipment. A total of 120 clinical and environmental bact...

  3. Time series analysis of cholera in Matlab, Bangladesh, during 1988-2001.

    Science.gov (United States)

    Ali, Mohammad; Kim, Deok Ryun; Yunus, Mohammad; Emch, Michael

    2013-03-01

    The study examined the impact of in-situ climatic and marine environmental variability on cholera incidence in an endemic area of Bangladesh and developed a forecasting model for understanding the magnitude of incidence. Diarrhoea surveillance data collected between 1988 and 2001 were obtained from a field research site in Matlab, Bangladesh. Cholera cases were defined as Vibrio cholerae O1 isolated from faecal specimens of patients who sought care at treatment centres serving the Matlab population. Cholera incidence for 168 months was correlated with remotely-sensed sea-surface temperature (SST) and in-situ environmental data, including rainfall and ambient temperature. A seasonal autoregressive integrated moving average (SARIMA) model was used for determining the impact of climatic and environmental variability on cholera incidence and evaluating the ability of the model to forecast the magnitude of cholera. There were 4,157 cholera cases during the study period, with an average of 1.4 cases per 1,000 people. Since monthly cholera cases varied significantly by month, it was necessary to stabilize the variance of cholera incidence by computing the natural logarithm to conduct the analysis. The SARIMA model shows temporal clustering of cholera at one- and 12-month lags. There was a 6% increase in cholera incidence with a minimum temperature increase of one degree celsius in the current month. For increase of SST by one degree celsius, there was a 25% increase in the cholera incidence at currrent month and 18% increase in the cholera incidence at two months. Rainfall did not influenc to cause variation in cholera incidence during the study period. The model forecast the fluctuation of cholera incidence in Matlab reasonably well (Root mean square error, RMSE: 0.108). Thus, the ambient and sea-surface temperature-based model could be used in forecasting cholera outbreaks in Matlab.

  4. Cholera dynamics with Bacteriophage infection: A mathematical study

    International Nuclear Information System (INIS)

    Misra, A.K.; Gupta, Alok; Venturino, Ezio

    2016-01-01

    Highlights: • A mathematical model for the biological control of cholera has been proposed. • The feasibility and stability of all the equilibria have been investigated. • The ODE model is found to exhibit Hopf-bifurcation. • Conditions of global asymptotic stability have been obtained. • The impact of important parameters on cholera spread has been shown. - Abstract: Mathematical modeling of waterborne diseases, such as cholera, including a biological control using Bacteriophage viruses in the aquatic reservoirs is of great relevance in epidemiology. In this paper, our aim is twofold: at first, to understand the cholera dynamics in the region around a water body; secondly, to understand how the spread of Bacteriophage infection in the cholera bacterium V. cholerae controls the disease in the human population. For this purpose, we modify the model proposed by Codeço, for the spread of cholera infection in human population and the one proposed by Beretta and Kuang, for the spread of Bacteriophage infection in the bacteria population [1, 2]. We first discuss the feasibility and local asymptotic stability of all the possible equilibria of the proposed model. Further, in the numerical investigation, we have found that the parameter ϕ, called the phage adsorption rate, plays an important role. There is a critical value, ϕ c , at which the model possess Hopf-bifurcation. For lower values than ϕ c , the equilibrium E * is unstable and periodic solutions are observed, while above ϕ c , the equilibrium E * is locally asymptotically stable, and further shown to be also globally asymptotically stable. We investigate the effect of the various parameters on the dynamics of the infected humans by means of numerical simulations.

  5. [Cholera in 1831. Challenges for science and the federal government].

    Science.gov (United States)

    Stamm-Kuhlmann, T

    1989-01-01

    The peak of the first great cholera pandemic in 1831 fomented the controversy among contagionists and non-contagionists. In the following year the public debate centered around the correct interpretation of the recent experiences with cholera. The central government of the bureaucratic-absolutist monarchy in Prussia adhered to a firmly contagionist interpretation of the disease and reacted accordingly. Local authorities in Königsberg and Berlin and the bourgeoisie in the merchant city of Danzig, however, stressed the destructive consequences of the cordon system. They considered the results of an interruption in trade and industry to be worse than the damage inflicted by the epidemic. The summer of 1831 demonstrated that cholera could not be stopped by the cordons, but the King's medical advisors nevertheless remained contagionists. Non-contagionists put forward several hypotheses to explain the origin and the spreading of cholera, mainly "miasma" theory and the Hippocratic paradigm of "epidemic constitution". The correlation between poverty and disease, however, was widely noticed. Physicians in the city of Bremen pointed to the necessity of sanitary precautions to be taken in cholera-free periods. On the other hand, many "honest" citizens believed that individuals with a "dissolute" conduct of life were more at risk to contract cholera than others. Instead of costly sanitary policies, the well-to-do classes preferred to identify the defense against cholera with the segregation of unwelcome elements of society. The article is based on hitherto unpublished sources from the former Prussian State Archives at Merseburg, GDR, and the State Archive of the Hanseatic City of Bremen.

  6. Efficacy of Ciprofloxacin for Treatment of Cholera Associated with Diminished Susceptibility to Ciprofloxacin to Vibrio cholerae O1.

    Science.gov (United States)

    Khan, Wasif Ali; Saha, Debasish; Ahmed, Sabeena; Salam, Mohammed Abdus; Bennish, Michael Louis

    2015-01-01

    We identified a poor clinical response to treatment of cholera with a single 1 g dose of ciprofloxacin, a standard treatment for cholera. To determine reasons for the poor response and better therapeutic approaches we examined the minimal inhibitor concentration (MIC, n = 275) and disc-diffusion zone sizes (n = 205) for ciprofloxacin and nalidixic acid of V. cholerae O1 strains isolated in Bangladesh from 1994 to 2012, and reexamined data from 161 patients infected with Vibrio cholerae O1 recruited in four clinical trials who received single- or multiple-dose ciprofloxacin for treatment of cholera and compared their clinical response to the V. cholerae O1 susceptibility. Although all 275 isolates of V. cholerae O1 remained susceptible to ciprofloxacin using standard MIC and disc-diffusion thresholds, the MIC90 to ciprofloxacin increased from 0.010 in 1994 to 0.475 μgm/ml in 2012. Isolates became frankly resistant to nalidixic with the MIC90 increasing from 21 μgm/ml in 1994 to >256 μgm/ml and 166 of 205 isolates from 1994 to 2005 being frankly resistant using disc-diffusion testing. Isolates resistant to nalidixic acid by disc-diffusion testing had a median ciprofloxacin MIC of 0.190 μgm/ml (10th-90th centiles 0.022 to 0.380); nalidixic acid-susceptible isolates had a median ciprofloxacin MIC of 0.002 (0.002 to 0.012).The rate of clinical success with single-dose ciprofloxacin treatment for nalidixic acid-susceptible strains was 94% (61 of 65 patients) and bacteriologic success 97% (63/65) compared to 18% (12/67) and 8% (5/67) respectively with nalidixic acid-resistant strains (Ptreatment with ciprofloxacin had 86% and 100% clinical and bacteriologic success rates respectively in patients infected with nalidixic acid-susceptible strains of V. cholerae O1 compared to clinical success 67% and bacteriologic success 60% with nalidixic acid-resistant strains. Single-dose ciprofloxacin is not effective for treating cholera caused by V. cholerae O1 with diminished

  7. 9 CFR 309.5 - Swine; disposal because of hog cholera.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Swine; disposal because of hog cholera... INSPECTION AND CERTIFICATION ANTE-MORTEM INSPECTION § 309.5 Swine; disposal because of hog cholera. (a) All swine found by an inspector to be affected with hog cholera shall be identified as U.S. Condemned and...

  8. A model to predict when a cholera outbreak might hit the Congo

    Science.gov (United States)

    Schultz, Colin

    2014-09-01

    In 2011, as many as 600,000 people in 58 countries contracted cholera, with thousands succumbing to the disease. In most countries, cholera is rare. In others, like the Democratic Republic of the Congo, cholera is an endemic threat, always lurking in the background waiting for the right set of conditions to spark an outbreak.

  9. The protective activity of tea catechins against experimental infection by Vibrio cholerae O1.

    Science.gov (United States)

    Toda, M; Okubo, S; Ikigai, H; Suzuki, T; Suzuki, Y; Hara, Y; Shimamura, T

    1992-01-01

    Tea catechins inhibited the fluid accumulation induced by cholera toxin in sealed adult mice. The catechins also reduced fluid accumulation by Vibrio cholerae O1 in ligated intestinal loops of rabbits. These findings suggest that tea catechins may possess protective activity against V. cholerae O1.

  10. Epidemic Cholera in a Crowded Urban Environment, Port-au-Prince, Haiti

    OpenAIRE

    Dunkle, Stacie E.; Mba-Jonas, Adamma; Loharikar, Anagha; Fouché, Bernadette; Peck, Mireille; Ayers, Tracy; Archer, W. Roodly; De Rochars, Valery M. Beau; Bender, Thomas; Moffett, Daphne B.; Tappero, Jordan W.; Dahourou, George; Roels, Thierry H.; Quick, Robert

    2011-01-01

    We conducted a case–control study to investigate factors associated with epidemic cholera. Water treatment and handwashing may have been protective, highlighting the need for personal hygiene for cholera prevention in contaminated urban environments. We also found a diverse diet, a possible proxy for improved nutrition, was protective against cholera.

  11. Detection of cholera (ctx) and zonula occludens (zot) toxin genes in Vibrio cholerae O1, O139 and non-O1 strains.

    Science.gov (United States)

    Rivera, I G; Chowdhury, M A; Sanchez, P S; Sato, M I; Huq, A; Colwell, R R; Martins, M T

    1995-09-01

    Vibrio cholerae O1 and V. cholerae non-O1 strains isolated from environmental samples collected in São Paulo, Brazil, during cholera epidemics and pre-epidemic periods were examined for the presence of toxin genes. V. cholerae O1 strains isolated from clinical samples in Peru and Mexico, and V. cholerae O139 strains from India were also examined for the presence of ctx (cholera toxin gene) and zot (zonula occludens toxin gene) by polymerase chain reaction (PCR). A modified DNA-extraction method applied in this study yielded satisfactory recovery of genomic DNA from vibrios. Results showed that strains of V. cholerae O1 isolated during the preepidemic period were ctx (-)/zot (-) whereas strains isolated during the epidemic were ctx (+)/zot (+). All V. cholerae non-O1 strains tested in the study were ctx (-)/zot (-), whereas all V. cholerae O139 strains were ctx (+)/zot (+). Rapid detection of the virulence genes (ctx and zot) can be achieved by PCR and this can serve as an important tool in the epidemiology and surveillance of V. cholerae.

  12. Cholera outbreak caused by drug resistant Vibrio cholerae serogroup O1 biotype ElTor serotype Ogawa in Nepal; a cross-sectional study

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    Pappu Kumar Gupta

    2016-06-01

    Full Text Available Abstract Background Cholera is a major cause of mortality and morbidity in underdeveloped countries including Nepal. Recently drug resistance in Vibrio cholerae has become a serious problem mainly in developing countries. The main objectives of our study were to investigate the occurrence of Vibrio cholerae in stool samples from patients with watery diarrhea and to determine the antimicrobial susceptibility patterns of V. cholerae isolates. Methods A total of 116 stool samples from patients suffering from watery diarrhea during July to December 2012 were obtained from outbreak areas from all over Nepal. Alkaline peptone water and thiosulphate citrate bile salt sucrose agar (TCBS were used to isolate the Vibrio cholerae. The isolates were identified with the help of colony morphology, Gram’s staining, conventional biochemical testing, serotyping and biotyping. Antimicrobial susceptibility testing was performed by determining the minimum inhibitory concentration (MIC by agar dilution method. Results Vibrio cholerae was isolated from 26.72 % of total samples. All isolated Vibrio cholerae were confirmed to be Vibrio cholerae serogoup O1 biotype El Tor and serotype Ogawa. All isolates were resistant to ampicillin and cotrimoxazole. Twenty nine isolates were resistant toward two different classes of antibiotics, one strain was resistant to three different classes of antibiotics and one strain was resistant to four different classes of antibiotics. According to the definition of the multidrug resistant bacteria; 6.45 % of the strains of Vibrio cholerae were found to be multidrug resistant. Conclusions Cholera due to multidrug resistant Vibrio cholerae is also possible in Nepal. According to the antimicrobial susceptibility pattern of Vibrio cholerae in our study we recommend to use any antibiotics among tetracycline, doxycycline, levofloxacin, azithromycin, chloramphenicol and ciprofloxacin for preliminary treatment of cholera in Nepal.

  13. Delivery cost analysis of a reactive mass cholera vaccination campaign: a case study of Shanchol™ vaccine use in Lake Chilwa, Malawi.

    Science.gov (United States)

    Ilboudo, Patrick G; Le Gargasson, Jean-Bernard

    2017-12-19

    Cholera is a diarrheal disease that produces rapid dehydration. The infection is a significant cause of mortality and morbidity. Oral cholera vaccine (OCV) has been propagated for the prevention of cholera. Evidence on OCV delivery cost is insufficient in the African context. This study aims to analyze Shanchol vaccine delivery costs, focusing on the vaccination campaign in response of a cholera outbreak in Lake Chilwa, Malawi. The vaccination campaign was implemented in two rounds in February and March 2016. Structured questionnaires were used to collect costs incurred for each vaccination related activity, including vaccine procurement and shipment, training, microplanning, sensitization, social mobilization and vaccination rounds. Costs collected, including financial and economic costs were analyzed using Choltool, a standardized cholera cost calculator. In total, 67,240 persons received two complete doses of the vaccine. Vaccine coverage was higher in the first round than in the second. The two-dose coverage measured with the immunization card was estimated at 58%. The total financial cost incurred in implementing the campaign was US$480275 while the economic cost was US$588637. The total financial and economic costs per fully vaccinated person were US$7.14 and US$8.75, respectively, with delivery costs amounting to US$1.94 and US$3.55, respectively. Vaccine procurement and shipment accounted respectively for 73% and 59% of total financial and economic costs of the total vaccination campaign costs while the incurred personnel cost accounted for 13% and 29% of total financial and economic costs. Cost for delivering a single dose of Shanchol was estimated at US$0.97. This study provides new evidence on economic and financial costs of a reactive campaign implemented by international partners in collaboration with MoH. It shows that involvement of international partners' personnel may represent a substantial share of campaign's costs, affecting unit and vaccine

  14. Natural Disasters and Cholera Outbreaks: Current Understanding and Future Outlook.

    Science.gov (United States)

    Jutla, Antarpreet; Khan, Rakibul; Colwell, Rita

    2017-03-01

    Diarrheal diseases remain a serious global public health threat, especially for those populations lacking access to safe water and sanitation infrastructure. Although association of several diarrheal diseases, e.g., cholera, shigellosis, etc., with climatic processes has been documented, the global human population remains at heightened risk of outbreak of diseases after natural disasters, such as earthquakes, floods, or droughts. In this review, cholera was selected as a signature diarrheal disease and the role of natural disasters in triggering and transmitting cholera was analyzed. Key observations include identification of an inherent feedback loop that includes societal structure, prevailing climatic processes, and spatio-temporal seasonal variability of natural disasters. Data obtained from satellite-based remote sensing are concluded to have application, although limited, in predicting risks of a cholera outbreak(s). We argue that with the advent of new high spectral and spatial resolution data, earth observation systems should be seamlessly integrated in a decision support mechanism to be mobilize resources when a region suffers a natural disaster. A framework is proposed that can be used to assess the impact of natural disasters with response to outbreak of cholera, providing assessment of short- and long-term influence of climatic processes on disease outbreaks.

  15. On the probability of extinction of the Haiti cholera epidemic

    Science.gov (United States)

    Bertuzzo, Enrico; Finger, Flavio; Mari, Lorenzo; Gatto, Marino; Rinaldo, Andrea

    2014-05-01

    Nearly 3 years after its appearance in Haiti, cholera has already exacted more than 8,200 deaths and 670,000 reported cases and it is feared to become endemic. However, no clear evidence of a stable environmental reservoir of pathogenic Vibrio cholerae, the infective agent of the disease, has emerged so far, suggesting that the transmission cycle of the disease is being maintained by bacteria freshly shed by infected individuals. Thus in principle cholera could possibly be eradicated from Haiti. Here, we develop a framework for the estimation of the probability of extinction of the epidemic based on current epidemiological dynamics and health-care practice. Cholera spreading is modelled by an individual-based spatially-explicit stochastic model that accounts for the dynamics of susceptible, infected and recovered individuals hosted in different local communities connected through hydrologic and human mobility networks. Our results indicate that the probability that the epidemic goes extinct before the end of 2016 is of the order of 1%. This low probability of extinction highlights the need for more targeted and effective interventions to possibly stop cholera in Haiti.

  16. Non-01 Vibrio cholerae infections in Cancun, Mexico.

    Science.gov (United States)

    Finch, M J; Valdespino, J L; Wells, J G; Perez-Perez, G; Arjona, F; Sepulveda, A; Bessudo, D; Blake, P A

    1987-03-01

    To determine the role of Vibrio cholerae as a cause of diarrheal illness in Cancun, Mexico, an investigation was conducted in July and August 1983. Although toxigenic V. cholerae 01 were not found, non-01 V. cholerae were isolated from 22 (16%) of 134 stools from persons with diarrheal illness and none of 22 stools from well persons; 58 (92%) of 63 sewage samples; 12 (86%) of 14 untreated well water samples; a home storage tank for treated water; and 5 (21%) of 24 samples of raw seafood. None of the V. cholerae isolates from patients were toxigenic. The illness occurred mainly in small children, and were characterized principally by diarrhea and abdominal pain. No patient was seriously ill, and all recovered without sequelae. Seven different serotypes of non-01 V. cholerae were isolated from the stool specimens, and Smith serotype 12 accounted for 10 (46%) of the 22 isolates. A matched-pair case-control study found that cases were more likely than controls to have eaten home prepared gelatin (P = 0.03, OR = 5/0) and seafood (P = 0.06, OR = 4/0).

  17. Antibiotic Resistance of Vibrio cholerae Isolates from Kashan, Iran

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    Afzali H.MD,

    2016-03-01

    Full Text Available Abstract Aims: Cholera is an acute diarrheal disease that can lead to severe dehydration and death. Antibiotic resistance is a big challenge in infective disease like Cholera. The present study aimed to understand the characteristics and trends of antibiotic resistance of V. cholerae isolations in and around Kashan, Iran. Instrument & Methods: In this descriptive cross-sectional study, samples were gathered using census method from 1998 to 2013 in Kashan, Iran. 1132 fecal samples of patients with acute diarrhea and 237 samples of suspected water samples were taken. The serotypes and biotypes were determined by an enzymatic method. Antibiotic susceptibility test was performed by using Disk Diffusion Method. Data were analyzed using SPSS 23 software. Fisher-exact and Chi-square tests were used to compare the statistical parameters. Findings: 96 fecal samples (8.5% and 18 water samples (7.6% were positive for Vibrio cholerae. Non-agglutinating (Nag isolates (75.4% were more common than serotype Inaba (13.2% and Ogawa (11.4%. Nag serotypes were mostly resistant to cefixime (44% and ampicillin (33%. In contaminated water samples also the most frequent cases were Nag serotype (50%. Nag serotype showed 22.2% of resistance to ampicillin and nitrofurantoin. Conclusion: Vibrio cholerae isolates in Kashan, Iran, are highly resistant to antibiotics, especially Nag serotypes.

  18. Cholera ante portas – The re-emergence of cholera in Kinshasa after a ten-year hiatus

    Science.gov (United States)

    Bompangue, Didier; Vesenbeckh, Silvan Manuel; Giraudoux, Patrick; Castro, Marcia; Muyembe, Jean-Jacques; Kebela Ilunga, Benoît; Murray, Megan

    2012-01-01

    Background: Cholera is an endemic disease in certain well-defined areas in the east of the Democratic Republic of Congo (DRC). The west of the country, including the mega-city Kinshasa, has been free of cases since mid 2001 when the last outbreak ended. Methods and Findings: We used routinely collected passive surveillance data to construct epidemic curves of the cholera cases and map the spatio-temporal progress of the disease during the first 47 weeks of 2011. We compared the spatial distribution of disease spread to that which occurred in the last cholera epidemic in Kinshasa between 1996 and 2001. To better understand previous determinants of cholera spread in this region, we conducted a correlation analysis to assess the impact of rainfall on weekly health zone cholera case counts between December 1998 and March 2001 and a Generalized Linear Model (GLM) regression analysis to identify factors that have been associated with the most vulnerable health zones within Kinshasa between October 1998 and June 1999. In February 2011, cholera reemerged in a region surrounding Kisangani and gradually spread westwards following the course of the Congo River to Kinshasa, home to 10 million people. Ten sampled isolates were confirmed to be Vibrio cholerae O1, biotype El Tor, serotype Inaba, resistant to trimethoprim-sulfa, furazolidone, nalidixic acid, sulfisoxaole, and streptomycin, and intermediate resistant to Chloramphenicol. An analysis of a previous outbreak in Kinshasa shows that rainfall was correlated with case counts and that health zone population densities as well as fishing and trade activities were predictors of case counts. Conclusion: Cholera is particularly difficult to tackle in the DRC. Given the duration of the rainy season and increased riverine traffic from the eastern provinces in late 2011, we expect further increases in cholera in the coming months and especially within the mega-city Kinshasa. We urge all partners involved in the response to remain

  19. Health impairments arising from drinking water resources contaminated with Vibrio cholerae.

    Science.gov (United States)

    Ramamurthy, T; Chakraborty, S; Nair, G B; Bhattacharya, S K

    2000-01-01

    The endemic and seasonal nature of cholera depends upon the survival of toxigenic Vibrio cholerae in various niches of the aquatic environment. To understand the transmission and ecology of V. cholerae, it is necessary to know which component in the aquatic ecosystem can harbor it and thus contribute to the endemic presence. Toxigenic V. cholerae is now recognized as an autochthonous member of the microflora in many aquatic environments based on its protracted survival and proliferation without losing the virulence determinants. This article summarizes knowledge about the ecology, survival strategies and elimination techniques of V. cholerae from natural waters with special reference to drinking water.

  20. Genome-wide study of the defective sucrose fermenter strain of Vibrio cholerae from the Latin American cholera epidemic.

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    Daniel Rios Garza

    Full Text Available The 7th cholera pandemic reached Latin America in 1991, spreading from Peru to virtually all Latin American countries. During the late epidemic period, a strain that failed to ferment sucrose dominated cholera outbreaks in the Northern Brazilian Amazon region. In order to understand the genomic characteristics and the determinants of this altered sucrose fermenting phenotype, the genome of the strain IEC224 was sequenced. This paper reports a broad genomic study of this strain, showing its correlation with the major epidemic lineage. The potentially mobile genomic regions are shown to possess GC content deviation, and harbor the main V. cholera virulence genes. A novel bioinformatic approach was applied in order to identify the putative functions of hypothetical proteins, and was compared with the automatic annotation by RAST. The genome of a large bacteriophage was found to be integrated to the IEC224's alanine aminopeptidase gene. The presence of this phage is shown to be a common characteristic of the El Tor strains from the Latin American epidemic, as well as its putative ancestor from Angola. The defective sucrose fermenting phenotype is shown to be due to a single nucleotide insertion in the V. cholerae sucrose-specific transportation gene. This frame-shift mutation truncated a membrane protein, altering its structural pore-like conformation. Further, the identification of a common bacteriophage reinforces both the monophyletic and African-Origin hypotheses for the main causative agent of the 1991 Latin America cholera epidemics.

  1. [Poland: cholera to typhus, 1831-1950].

    Science.gov (United States)

    Balinska, M A

    1999-12-01

    In this article devoted to Poland's direct and indirect role in the elaboration of contemporary international health structures and to her reputation as an epidemic reservoir of Europe, we consider how Poland came to be perceived as the cordon sanitaire of the West. Traditionally seen as upholding Western values, in the 19th and 20th centuries the country became increasingly associated with "Eastern plagues"-cholera and then typhus-coming from Russia and which could spread to the rest of Europe if Poland did not manage to contain them. When Poland was reconstituted as a nation-state in 1918, the new country won international recognition through her successful attempts to contain a typhus epidemic sweeping westwards from Russia. The Polish government convened the first European, League sponsored, health conference following the First World War. A Polish doctor, L. RAJCHMAN, was chosen to head up the League of Nations Health Organisation (forerunner of the WHO) and later (1946) founded UNICEF. Finally, we examine the key issue of exanthematous typhus in both world wars, exemplifying how a disease can come to be "ideologized", in this case by Nazi Germany. Typhus was the pretext used- in the name of "public health"-for segregating Polish citizens of Jewish origin and even killing them. Paradoxically, typhus was in the process of being eradicated when the war began and German policy of mass resettlements, sequestration, and starvation only spurred the epidemic they supposedly wished to control.

  2. A bibliography of references to avian cholera

    Science.gov (United States)

    Wilson, Sonoma S.

    1979-01-01

    Mrs. Wilson has made a genuine effort to include in this bibliography every significant reference to avian cholera since Louis Pasteur's articles appeared in 1880, although she recognizes the likelihood that a few have been overlooked. New listings have been added throughout 1978, but comprehensive coverage of the literature cannot be claimed beyond June of that year.Textbook accounts, because they are generally summaries of work published elsewhere, are excluded. Papers dealing primarily with the biology of Pasteurella multocida, as opposed to the disease it induces in birds, are also excluded, unless they report information of diagnostic usefulness. Short abstracts are not included unless the journals in which they are published are more widely available than those in which the complete articles appear or they are English summaries of foreign language articles.In compiling this bibliography, Mrs. Wilson has made extensive use of Biological Abstracts, the Pesticide Documentation Bulletin, and printouts generated by Bibliographic Retrieval Services, Inc. The "Literature Cited" sections of textbooks and journal articles pertinent to the subject were sources of many additional references. Regardless of the origin of the citation, its accuracy was confirmed by comparison with the original publication, except in those few instances (marked with an asterisk) when the journal was not on the shelves of the libraries accessible to us.The author will be grateful to users of the bibliography who point out errors or omissions.Wayne I. JensenMicrobiologist In Charge

  3. Salovum egg yolk containing antisecretory factor as an adjunct therapy in severe cholera in adult males: a pilot study.

    Science.gov (United States)

    Alam, Nur H; Ashraf, Hasan; Olesen, Maryam; Salam, Mohammed A; Gyr, Niklaus; Meier, Remy

    2011-08-01

    Cholera involves stimulation of intestinal secretory process in response to cholera toxin leading to profuse watery diarrhoea that might cause death due to dehydration unless timely rehydration therapy is initiated. Efforts to identify and test potential antisecretory agents are ongoing. Antisecretory factor (AF) is a naturally-occurring protein produced in the human secretory organs, including the intestine, with antisectory properties demonstrated in animal and human models of secretory diarrhoea. Salovum egg yolk powder contains antisecretory proteins in a much higher (500 times) concentration than that of normal hen eggs. This is achieved by feeding hens with specially-processed cereals, capable of inducing antisecretory proteins in the yolk. The aim of the study was to examine the effect of Salovum egg yolk powder containing AF in the treatment of adult cholera patients. In an open, randomized controlled trial (pilot study), 40 adult male patients with severe cholera were studied: 20 received standard treatment (oral rehydration solution, antibiotic, and usual hospital diet) plus Salovum egg yolk powder (study group) and 20 received standard treatment alone (control group). All the patients received tablet doxycycline (300 mg) once immediately after randomization. Written informed consent was obtained from each subject before enrollment. The main outcome measures were stool weight and duration of diarrhoea. The demographic and baseline clinical characteristics of the study patients were comparable between the groups. No significant differences were found in the mean stool weight, g/kg of body-weight during the first 24 hours [study vs control group, mean +/- standard deviation (SD), 218 +/- 119 vs 195 +/- 136], second 24 hours (mean +/- SD, 23 +/- 39 vs 22 +/- 34), and cumulative up to 72 hours (mean +/- SD, 245 +/- 152 vs 218 +/- 169). The duration (hours) of diarrhoea after admission in the hospital was also similar in both the groups (mean +/- SD, 33 +/- 14

  4. Flow cytofluorometric monitoring of leukocyte apoptosis in experimental cholera

    Science.gov (United States)

    Lotsmanova, Ekaterina Y.; Kravtsov, Alexander L.; Livanova, Ludmila F.; Kobkova, Irina M.; Kuznetsov, Oleg S.; Shchukovskaya, Tatyana N.; Smirnova, Nina I.; Kutyrev, Vladimir V.

    2003-10-01

    Flow cytofluorometric DNA analysis was applied to determine of the relative contents of proliferative (more then 2C DNA per cell) and apoptotic (less then 2C DNA per cell) leukocytes in blood of adult rabbits, challenged with 10,000 times the 50 % effective dose of Vibrio cholerae virulent strain by the RITARD technique. It has been shown that irreversible increase the percentage of cells carrying DNA in the degradation stage brings to disbalance between the genetically controlled cell proliferation and apoptosis that leads to animal death from the cholera infection. Such fatal changes were not observed in challenging of immunized animals that were not died. Thus received data show that the flow cytofluorometric measurements may be used for detection of transgressions in homeostasis during acute infection diseases, for outlet prognosis of the cholera infection.

  5. Respon Imun Anak Babi Pasca Vaksinasi Hog Cholera

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    I Made Jayanata

    2016-10-01

    Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh antibodi maternal terhadap titer antibodi anak babi yang di vaksin hog cholera umur 7 hari. Penelitian menggunakan tujuh sampel babi dari induk yang divaksin secara teratur yang diberikan perlakuan vaksinasi pada umur 7 hari. Pengambilan sampel serum dilakukan pravaksinasi (7 hari, dan satu minggu serta dua minggu pasca vaksinasi. Untuk menentukan titer antibodi virus Hog cholera pada sampel anak babi dilakukan uji ELISA. Data yang diperoleh kemudian dianalisis mengunakan paired sampel T test antara titer antibodi hog cholera. Hasil paired sample T test menunjukkan terjadinya penurunan titer antibodi maternal yang nyata (p<0,05 pada pra vaksinasi ( umur 7 hari dengan satu minggu pasca vaksinasi dan sangat nyata (p<0,01 dengan hari dua minggu pasca vaksinasi. Dari hasil penelitian ini dapat disimpulkan bahwa antibodi maternal yang tinggi akan mengakibatkan penurunan pada titer antibodi pasca vaksinasi. Perlu dilakukan penelitian lebih lanjut untuk mengetahui waktu vaksinasi yang efektif

  6. In situ measured elimination of Vibrio cholerae from brackish water.

    Science.gov (United States)

    Pérez, María Elena Martínez; Macek, Miroslav; Galván, María Teresa Castro

    2004-01-01

    In situ elimination of fluorescently labelled Vibrio cholerae (FLB) was measured in two saline water bodies in Mexico: in a brackish water lagoon, Mecoacán (Gulf of Mexico; State of Tabasco) and an athalassohaline lake, Alchichica (State of Puebla). Disappearance rates of fluorescently labelled V. cholera O1 showed that they were eliminated from the environment at an average rate of 32% and 63%/day, respectively (based on the bacterial standing stocks). The indirect immunofluorescence method confirmed the presence of V. cholerae O1 in the lagoon. However, the elimination of FLB was not directly related either to the presence or absence of the bacterium in the water body or to the phytoplankton concentration.

  7. Predictive modeling of cholera using GRACE and TRMM satellite data

    Science.gov (United States)

    Jutla, A.; Akanda, A. S. S.; Colwell, R. R.

    2015-12-01

    Cholera outbreaks can be classified in three forms- epidemic (sudden or seasonal outbreaks), endemic (recurrence and persistence of the disease for several consecutive years) and mixed-mode endemic (combination of certain epidemic and endemic conditions) with significant spatial and temporal heterogeneity. Endemic cholera is related to floods and droughts in regions where water and sanitation infrastructure are inadequate or insufficient. With more than a decade of terrestrial water storage (TWS) data obtained from Gravity Recovery and Climate Experiment (GRACE), understanding dynamics of river discharge is now feasible. We explored lead-lag relationships between TWS in the Ganges-Brahmaputra-Meghna (GBM) basin and endemic cholera in Bangladesh. Since bimodal seasonal peaks in cholera in Bangladesh occur during the spring and autumn season, two separate models, between TWS and disease time series (2002 to 2010) were developed. TWS, hence water availability, showed an asymmetrical, strong association with spring (τ=-0.53; pcholera prevalence up to five to six months in advance. One unit (cm of water) decrease in water availability in the basin increased odds of above normal cholera by 24% [confidence interval (CI) 20-31%; pcholera in the autumn by 29% [CI:22-33%; pcholera is related with warm temperatures and heavy rainfall. Using TRMM data for several locations in Asia and Africa, probability of cholera increases 18% [CI:15-23%; p<0.05] after heavy precipitation resulted in a societal conditions where access to safe water and sanitation was disrupted. Results from mechanistic modeling framework using systems approach that include satellite based hydroclimatic information with tradition disease transmission models will also be presented.

  8. Vibrio cholerae classical biotype strains reveal distinct signatures in Mexico.

    Science.gov (United States)

    Alam, Munirul; Islam, M Tarequl; Rashed, Shah Manzur; Johura, Fatema-tuz; Bhuiyan, Nurul A; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Hasan, Nur-A; Colwell, Rita R; Cravioto, Alejandro

    2012-07-01

    Vibrio cholerae O1 classical (CL) biotype caused the fifth and sixth pandemics, and probably the earlier cholera pandemics, before the El Tor (ET) biotype initiated the seventh pandemic in Asia in the 1970s by completely displacing the CL biotype. Although the CL biotype was thought to be extinct in Asia and although it had never been reported from Latin America, V. cholerae CL and ET biotypes, including a hybrid ET, were found associated with areas of cholera endemicity in Mexico between 1991 and 1997. In this study, CL biotype strains isolated from areas of cholera endemicity in Mexico between 1983 and 1997 were characterized in terms of major phenotypic and genetic traits and compared with CL biotype strains isolated in Bangladesh between 1962 and 1989. According to sero- and biotyping data, all V. cholerae strains tested had the major phenotypic and genotypic characteristics specific for the CL biotype. Antibiograms revealed the majority of the Bangladeshi strains to be resistant to trimethoprim-sulfamethoxazole, furazolidone, ampicillin, and gentamicin, while the Mexican strains were sensitive to all of these drugs, as well as to ciprofloxacin, erythromycin, and tetracycline. Pulsed-field gel electrophoresis (PFGE) of NotI-digested genomic DNA revealed characteristic banding patterns for all of the CL biotype strains although the Mexican strains differed from the Bangladeshi strains in 1 to 2 DNA bands. The difference was subtle but consistent, as confirmed by the subclustering patterns in the PFGE-based dendrogram, and can serve as a regional signature, suggesting the pre-1991 existence and evolution of the CL biotype strains in the Americas, independent from Asia.

  9. A global map of suitability for coastal Vibrio cholerae under current and future climate conditions.

    Science.gov (United States)

    Escobar, Luis E; Ryan, Sadie J; Stewart-Ibarra, Anna M; Finkelstein, Julia L; King, Christine A; Qiao, Huijie; Polhemus, Mark E

    2015-09-01

    Vibrio cholerae is a globally distributed water-borne pathogen that causes severe diarrheal disease and mortality, with current outbreaks as part of the seventh pandemic. Further understanding of the role of environmental factors in potential pathogen distribution and corresponding V. cholerae disease transmission over time and space is urgently needed to target surveillance of cholera and other climate and water-sensitive diseases. We used an ecological niche model (ENM) to identify environmental variables associated with V. cholerae presence in marine environments, to project a global model of V. cholerae distribution in ocean waters under current and future climate scenarios. We generated an ENM using published reports of V. cholerae in seawater and freely available remotely sensed imagery. Models indicated that factors associated with V. cholerae presence included chlorophyll-a, pH, and sea surface temperature (SST), with chlorophyll-a demonstrating the greatest explanatory power from variables selected for model calibration. We identified specific geographic areas for potential V. cholerae distribution. Coastal Bangladesh, where cholera is endemic, was found to be environmentally similar to coastal areas in Latin America. In a conservative climate change scenario, we observed a predicted increase in areas with environmental conditions suitable for V. cholerae. Findings highlight the potential for vulnerability maps to inform cholera surveillance, early warning systems, and disease prevention and control. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Prevalence of Vibrio cholerae O1 serogroup in Assam, India: A hospital-based study.

    Science.gov (United States)

    Sharma, Ajanta; Dutta, Bornali Sarmah; Rasul, Elmy Samsun; Barkataki, Dipa; Saikia, Anjanamoyee; Hazarika, Naba Kumar

    2017-09-01

    Although cholera remains to be an important public health problem, studies on reliable population-based estimates of laboratory confirmed cholera in endemic areas are limited worldwide. The aim of this hospital-based study was to evaluate the prevalence of Vibrio cholerae serogroup in Assam, India, during 2003-2013. Stool samples/rectal swabs were collected from acute watery diarrhoea (AWD) cases during 2003-2013 and processed by standard microbiological procedures. Antibiotic sensitivity test was done following the Clinical and Laboratory Standards Institute guidelines. Year-wise epidemiological trend of cholera was analyzed. Cholera contributed to 3.93 per cent of AWD cases. In Assam, cholera was found to be more prevalent in the rural areas (6.7%) followed by the tea gardens (5.06%), urban slum (1.9%) and urban areas (1.4%). Highest proportion of cholera (13.7%) was observed in 0-10 yr age group. Of them, 11.5 per cent belonged to 0-5 yr age group. V. cholerae O1 El Tor serotype Ogawa was the predominant isolate. Multiple drug-resistant isolates of V. cholerae O1 Ogawa were reported in the study. Emergence of resistance amongst V. cholerae towards many antibiotics is a matter of concern. Hence, continuous surveillance for diarrhoeal disorders is necessary to control the future outbreaks of cholera in this region.

  11. Molecular Analyses of Vibrio cholerae O1 Clinical Strains, Including New Nontoxigenic Variants Isolated in Mexico during the Cholera Epidemic Years between 1991 and 2000

    OpenAIRE

    Lizárraga-Partida, Leonardo; Quilici, Marie-Laure

    2009-01-01

    International audience; We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI r...

  12. Unique Clones of Vibrio cholerae O1 El Tor with Haitian Type ctxB Allele Implicated in the Recent Cholera Epidemics from Nigeria, Africa.

    Science.gov (United States)

    Adewale, Akinsinde Kehinde; Pazhani, Gururaja Perumal; Abiodun, Iwalokun Bamidele; Afolabi, Oluwadun; Kolawole, Olukoya Daniel; Mukhopadhyay, Asish K; Ramamurthy, Thanadarayan

    2016-01-01

    The antimicrobial susceptibility patterns and genetic characteristics of Vibrio cholerae O1, which is responsible for several cholera epidemics in Nigeria, are not reported in detail since 2007. In this study, we screened V. cholerae O1 El Tor biotype isolates from cholera cases and water samples from different states to investigate their phenotypic and genetic attributes with special reference to their clonality. All the V. cholerae O1 biotype El Tor isolates isolated during 2007-2013 were susceptible to fluoroquinolones and tetracycline, the drugs currently used in the treatment of cholera cases in Nigeria. Emergence of CT genotype 7 (Haitian type of ctxB allele) was predominantly seen among Ogawa serotype and the CT genotype 1 (classical ctxB allele) was mostly found in Inaba serotype. Overall, V. cholerae O1 from clinical and water samples were found to be closely related as determined by the pulsed-field gel electrophoresis. V. cholerae isolates from Abia, Kano and Bauchi were found to be genetically distinct from the other states of Nigeria. Fecal contamination of the water sources may be the possible source of the cholera infection. Combined prevalence of Haitian and classical ctxB alleles were detected in Ogawa and Inaba serotypes, respectively. This study further demonstrated that V. cholerae O1 with the ctxB has been emerged similar to the isolates reported in Haiti. Our findings suggest that the use of fluoroquinolones or tetracycline/doxycycline may help in the effective management of acute cholera in the affected Nigerian states. In addition, strengthening the existing surveillance in the hospitals of all the states and supply of clean drinking water may control cholera outbreaks in the future.

  13. Recommendations of the Advisory Committee on Immunization Practices for Use of Cholera Vaccine.

    Science.gov (United States)

    Wong, Karen K; Burdette, Erin; Mahon, Barbara E; Mintz, Eric D; Ryan, Edward T; Reingold, Arthur L

    2017-05-12

    Cholera, caused by infection with toxigenic Vibrio cholerae bacteria of serogroup O1 (>99% of global cases) or O139, is characterized by watery diarrhea that can be severe and rapidly fatal without prompt rehydration. Cholera is endemic in approximately 60 countries and causes epidemics as well. Globally, cholera results in an estimated 2.9 million cases of disease and 95,000 deaths annually (1). Cholera is rare in the United States, and most U.S. cases occur among travelers to countries where cholera is endemic or epidemic. Forty-two U.S. cases were reported in 2011 after a cholera epidemic began in Haiti (2); however, <25 cases per year have been reported in the United States since 2012.

  14. Association of Heavy Rainfall on Genotypic Diversity in V. cholerae Isolates from an Outbreak in India

    Directory of Open Access Journals (Sweden)

    A. K. Goel

    2011-01-01

    Full Text Available The outbreak of waterborne disease cholera has been associated with rainfall and flooding events by contamination of potable water with environmental Vibrio cholerae. The continuation of the epidemic in a region, however, is often due to secondary transmission of the initial outbreak strain through human waste. This paper reports, on the contrary, a rapid shift of genotype from one V. cholerae strain to another one in an epidemic region. V. cholerae isolated from patients during 2005 cholera epidemic in Chennai, India were characterized using PCR identification of toxin genes, antibiogram, and genomic fingerprinting analysis. The results showed that in spite of the similarity of toxin genes and antibiogram, the Vibrio isolates grouped into two different clusters based on the ERIC-PCR fingerprinting. Each cluster corresponded to a distinct peak of cholera outbreak, which occurred after separate heavy rainfall. The results suggest that the rainfall event can bring various genotypes of V. cholerae strains causing multiple outbreaks.

  15. Experimental parameters differentially affect the humoral response of the cholera-toxin-based murine model of food allergy

    DEFF Research Database (Denmark)

    Kroghsbo, S.; Christensen, Hanne Risager; Frøkiær, Hanne

    2003-01-01

    Background: Recent studies have developed a murine model of IgE-mediated food allergy based on oral coadministration of antigen and cholera toxin (CT) to establish a maximal response for studying immunopathogenic mechanisms and immunotherapeutic strategies. However, for studying subtle...... interested in characterizing the individual effects of the parameters in the CT-based model: CT dose, antigen type and dose, and number of immunizations. Methods: BALB/c mice were orally sensitized weekly for 3 or 7 weeks with graded doses of CT and various food antigens (soy-trypsin inhibitor, ovalbumin...... of the antibody response depended on the type of antigen and number of immunizations. Conclusions: The critical parameters of the CT-based murine allergy model differentially control the intensity and kinetics of the developing immune response. Adjustment of these parameters could be a key tool for tailoring...

  16. Polio endgame: the global introduction of inactivated polio vaccine.

    Science.gov (United States)

    Patel, Manish; Zipursky, Simona; Orenstein, Walt; Garon, Julie; Zaffran, Michel

    2015-05-01

    In 2013, the World Health Assembly endorsed a plan that calls for the ultimate withdrawal of oral polio vaccines (OPV) from all immunization programs globally. The withdrawal would begin in a phased manner with removal of the type 2 component of OPV in 2016 through a global switch from trivalent OPV to bivalent OPV (containing only types 1 and 3). To mitigate risks associated with immunity gaps after OPV type 2 withdrawal, the WHO Strategic Advisory Group of Experts has recommended that all 126 OPV-only using countries introduce at least one dose of inactivated polio vaccine into routine immunization programs by end-2015, before the trivalent OPV-bivalent OPV switch. The introduction of inactivated polio vaccine would reduce risks of reintroduction of type 2 poliovirus by providing some level of seroprotection, facilitating interruption of transmission if outbreaks occur, and accelerating eradication by boosting immunity to types 1 and 3 polioviruses.

  17. Antigenic characterization of a formalin-inactivated poliovirus vaccine derived from live-attenuated Sabin strains.

    Science.gov (United States)

    Tano, Yoshio; Shimizu, Hiroyuki; Martin, Javier; Nishimura, Yorihiro; Simizu, Bunsiti; Miyamura, Tatsuo

    2007-10-10

    A candidate inactivated poliovirus vaccine derived from live-attenuated Sabin strains (sIPV), which are used in the oral poliovirus vaccine (OPV), was prepared in a large-production scale. The modification of viral antigenic epitopes during the formalin inactivation process was investigated by capture ELISA assays using type-specific and antigenic site-specific monoclonal antibodies (MoAbs). The major antigenic site 1 was modified during the formalin inactivation of Sabin 1. Antigenic sites 1-3 were slightly modified during the formalin inactivation of Sabin 2 strain. Sites 1 and 3 were altered on inactivated Sabin 3 virus. These alterations were different to those shown by wild-type Saukett strain, used in conventional IPV (cIPV). It has been previously reported that type 1 sIPV showed higher immunogenicity to type 1 cIPV whereas types 2 and 3 sIPV induced lower level of immunogenicity than their cIPV counterparts. Our results suggest that the differences in epitope structure after formalin inactivation may account, at least in part, for the observed differences in immunogenicity between Sabin and wild-type inactivated poliovaccines.

  18. A recent outbreak of cholera due to Vibrio cholerae O1 Ogawa in & around Chandigarh, North India.

    Science.gov (United States)

    Taneja, Neelam; Kaur, Jasjit; Sharma, Kusum; Singh, Malkit; Kalra, J K; Sharma, N M; Sharma, Meera

    2003-06-01

    An outbreak of cholera caused by Vibrio cholerae O1 Ogawa occurred in and around Chandigarh during July 22-31, 2002. Of the 303 patients admitted to two hospitals, 82 were confirmed by culture. Two rehabilitation colonies located at the periphery of Chandigarh were mainly affected. The isolates were biotyped as Eltor and were susceptible to many antibiotics. Thirty one (35.2%) of 88 water samples showed evidence of faecal contamination. The survey of the area revealed sewage contamination of the drinking water supply. The outbreak was controlled by providing safe drinking water to the people and correcting the defects in the sewage and water pipelines.

  19. Irradiation mucositis and oral flora

    International Nuclear Information System (INIS)

    Spijkervet, F.K.L.

    1989-01-01

    This study, which is motivated by the substantial morbidity of local signs of mucositis and generalized symptoms that result from mucositis induced by therapeutic irradiation, has the following objectives: To investigate if it is possible to prevent irradiation mucositis via oral flora elimination, and, if it is true that flora plays a role in irradiation mucositis, what fraction of the oral flora may be involved; to evaluate oral Gram-negative bacillary carriage; to investigate the possibility to eradicate Gram-negative bacilli from the oral cavity; to evaluate oral yeast carriage; to investigate the possibility to eradicate yeasts stomatitis and the 'selectivity' of elimination of flora. Two methods are described for monitoring alterations of mucositis of the oral cavity and changes in oral flora. Chlorhexidine has been tested as the commonly used prophylaxis. The effect of chlorhexidine 0.1% rinses on oral flora and mucositis has been studied in a prospective placebo controlled double blind randomized programme. The results of the influence of saliva on the antimicrobial activity of chlorhexidine and the results of selective elimination of oral flora in irradiated patients who have head and neck cancer are reported. Salivary inactivation of the topical antimicrobials used for selective elimination of oral flora has been studied and the results are reported. Finally, the objectives that have been achieved (or not) are delineated. The significance of the results of the study are discussed in terms of published information and further lines of research are suggested. (author). 559 refs.; 29 figs.; 20 tabs

  20. Next Generation Inactivated Polio Vaccine Manufacturing to Support Post Polio-Eradication Biosafety Goals

    NARCIS (Netherlands)

    Thomassen, Y.E.; Oever, van 't A.G.; Oijen, van M.G.C.T.; Wijffels, R.H.; Pol, van der L.A.; Bakker, W.A.M.

    2013-01-01

    Worldwide efforts to eradicate polio caused a tipping point in polio vaccination strategies. A switch from the oral polio vaccine, which can cause circulating and virulent vaccine derived polioviruses, to inactivated polio vaccines (IPV) is scheduled. Moreover, a manufacturing process, using

  1. Co-variations of Cholera with Climatic and Environmental ...

    African Journals Online (AJOL)

    Significant co-variations were found between seasonally adjusted cases and coastal ocean chlorophyll a and to some degree sea surface temperature, both lagged by one to four months. Cholera cases in Dar es Salaam were also weakly related to the Indian Ocean Dipole Mode Index lagged by 5 months, suggesting that it ...

  2. cholera epidemiology in zambia from 2000 to 2010: implications for ...

    African Journals Online (AJOL)

    2013-10-10

    Oct 10, 2013 ... Zambian cholera data on the global health atlas to ensure consistency [6]. ... Management Committee (NEPPC&MC) meetings were also .... The inadequate water supply situation for Lusaka ... maintaining safe water chain at the household level through ... cost and logistics for administration needs to be.

  3. Vibrio Cholerae 01 Infections In Jos, Nigeria | Opajobi | African ...

    African Journals Online (AJOL)

    A study to determine the prevalence of Vibrio cholerae 01 in stool sample submitted for routine examination of enteric pathogens, as well as identify the serotypes and antibiogram of the isolates to commonly used antibiotics was undertaken. The survey involved the examination of 774 (763 stool and 11 rectal swabs) ...

  4. Endemicity of cholera in Nigeria: A mathematical model to ...

    African Journals Online (AJOL)

    The focal point is to investigate the persistent endemic nature of cholera in Nigeria using mathematical model. We found that, there can be no backward bifurcation because there existed only one positive endemic equilibrium. In other words, it is not possible for multiple endemic equilibria to exist if the reproduction number ...

  5. The case of cholera preparedness, response and prevention in the ...

    African Journals Online (AJOL)

    In this paper the authors seek to identify the most appropriate model for a regional co-ordination mechanism for cholera preparedness, response and prevention. The qualitative mixed-method data collection approach that was followed revealed the need for alternative solutions, including a socio-political understanding of ...

  6. Host-pathogen interactions: A cholera surveillance system

    Energy Technology Data Exchange (ETDEWEB)

    Wright, Aaron T.

    2016-02-22

    Bacterial pathogen-secreted proteases may play a key role in inhibiting a potentially widespread host-pathogen interaction. Activity-based protein profiling enabled the identification of a major Vibrio cholerae serine protease that limits the ability of a host-derived intestinal lectin to bind to the bacterial pathogen in vivo.

  7. Factors associated to populations' behaviour towards cholera in ...

    African Journals Online (AJOL)

    A disease related to hygiene, cholera is an affection which rages for centuries in the endemic states with epidemic hatchings worldwide. Benin, in particular in its littoral region, is not spared by the disease. The objective of this study was to determine the behavioural factors of the bad hygiene practice of the populations from ...

  8. [Cholera in Mexico City during the nineteenth century].

    Science.gov (United States)

    Marquez Morfin, L

    1992-01-01

    The author draws on epidemiological and historical records for this description of the demographic impact of the fatal cholera epidemics of 1833 and 1848-1850 on the population of Mexico City, Mexico. Consideration is given to political, economic, and social factors that influenced the spread of the disease.

  9. [The cholera epidemic of 1833 and mortality in Mexico City].

    Science.gov (United States)

    Velasco, M D

    1992-01-01

    The author examines the impact of the 1833 cholera epidemic in Mexico City, Mexico, on social, economic, and political aspects of life in that city. She finds that some five percent of the population died during the epidemic, and enumerates them by age and sex.

  10. A comparison of various modelling approaches applied to Cholera ...

    African Journals Online (AJOL)

    The analyses are demonstrated on data collected from Beira, Mozambique. Dynamic regression was found to be the preferred forecasting method for this data set. Keywords:Cholera, modelling, signal processing, dynamic regression, negative binomial regression, wavelet analysis, cross-wavelet analysis. ORiON Vol.

  11. Hydroclimatic mechanisms of cholera transmission in the Bengal Delta

    Science.gov (United States)

    Tretkoff, Ernie

    2011-07-01

    Cholera, a deadly waterborne disease, remains a major threat in many areas of the world, including the Bengal Delta region. In this region, cholera outbreaks have two annual peaks; the first occurs during the dry season in the spring, and the second occurs in the fall following the wet season. However, the large-scale hydroclimatic processes underlying the propagation of the disease have not been well understood. Akanda et al. show that cholera outbreaks in the Bengal Delta region propagate from the coast to inland and from spring to fall following two distinct transmission cycles. The first outbreak begins in the spring near the coast when northward movement of plankton-rich seawater and increasing salinity promote the growth of cholera-causing bacteria in rivers, which are used for irrigation, sanitation, and consumption. The second outbreak begins in the fall, after summer floods and monsoons affect sanitation conditions that aid in bacterial transmission by contaminating waters over much of Bangladesh. (Water Resources Research, doi:10.1029/ 2010WR009914, 2011)

  12. Factors associated with cholera in Kenya, 2008-2013 | Cowman ...

    African Journals Online (AJOL)

    The data were analyzed using a zero-inflated negative binomial regression model. Results: Multivariate analysis indicated that the risk of cholera was associated with open defecation, use of unimproved water sources, poverty headcount ratio and the number of health facilities per 100,000 population (p < 0.05).

  13. [The in vitro action of plants on Vibrio cholerae].

    Science.gov (United States)

    Guevara, J M; Chumpitaz, J; Valencia, E

    1994-01-01

    Natural products of several plants, according to the geographic location, are used by Peruvian people in the popular treatment of diarrhea, with good success. When cholerae cases appeared in Peru, we were interested to know the "in vitro" effect against Vibrio cholerae 01, of these useful plants to treat diarrhea. The following plants were tested: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Punica granatum, Malus sativa, Cydonia oblonga, Chenopodium ambrosoides, Krameria triandria, Tea chinensis, Daucus carota, Persea gratissima, Psidium guayaba and Lippia dulcis. Decoction or infusion of the plants were used in the "in vitro" experiments. The following plants showed no "in vitro" effect against V. cholerae: Cichorium intybus, Althaea officinalis, Psorela glandulosa, Geranium maculatum, Chenopodium ambrosoides, Krameria triandria, Psidium guayaba, Lippia dulcis and Daucus carota. Decoction of Malus sativa and Cydenia oblonga showed bactericidal effect for their acidity and stone avocado (Persea gratissima) a late bactericidal effect. Tea infusión and the decoction of Punica granatum peel, showed the best bactericidal effect and we suggest to use them as to stop cholera spreading.

  14. In situ measured elimination of Vibrio cholerae from brackish water

    Czech Academy of Sciences Publication Activity Database

    Martínez-P., M. E.; Macek, Miroslav; Castro-G., M. T.

    2004-01-01

    Roč. 9, č. 1 (2004), s. 133-140 ISSN 1360-2276 R&D Projects: GA MŠk(CZ) ME 296 Grant - others:UNAM/DGAPA/PAPIT(MX) IN216796 Keywords : Vibrio cholerae * protozoan feeding * brackish water Subject RIV: EE - Microbiology, Virology Impact factor: 1.969, year: 2004

  15. Dynamics of cholera epidemics with impulsive vaccination and disinfection.

    Science.gov (United States)

    Sisodiya, Omprakash Singh; Misra, O P; Dhar, Joydip

    2018-04-01

    Waterborne diseases have a tremendous influence on human life. The contaminated drinking water causes water-borne disease like cholera. Pulse vaccination is an important and effective strategy for the elimination of infectious diseases. A waterborne disease like cholera can also be controlled by using impulse technique. In this paper, we have proposed a delayed SEIRB epidemic model with impulsive vaccination and disinfection. We have studied the pulse vaccination strategy and sanitation to control the cholera disease. The existence and stability of the disease-free and endemic periodic solution are investigated both analytically and numerically. It is shown that there exists an infection-free periodic solution, using the impulsive dynamical system defined by the stroboscopic map. It is observed that the infection-free periodic solution is globally attractive when the impulse period is less than some critical value. From the analysis of the model, we have obtained a sufficient condition for the permanence of the epidemic with pulse vaccination. The main highlight of this paper is to introduce impulse technique along with latent period into the SEIRB epidemic model to investigate the role of pulse vaccination and disinfection on the dynamics of the cholera epidemics. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. Survival of Vibrio cholerae in industrially polluted water, with ...

    African Journals Online (AJOL)

    containing industrial effluents. The effect of iron as well as pH on the survival of Vibrio cholerae (non-O1, El Tor and classical strains) in water samples from 12 points, where selected industrial effluents were discharged into rivers, was studied.

  17. Salmonella and Vibrio cholerae in Nile perch ( Lates niloticus ...

    African Journals Online (AJOL)

    The Nile perch (Lates niloticus) industry in East Africa has suffered severe economic losses in the last few years due to failure to comply with the microbiological standards of European Union (E.U). Fresh and frozen products have been suspected to be contaminated with Salmonella and Vibrio cholerae. This has led to a ...

  18. Assessing effects of cholera vaccination in the presence of interference.

    Science.gov (United States)

    Perez-Heydrich, Carolina; Hudgens, Michael G; Halloran, M Elizabeth; Clemens, John D; Ali, Mohammad; Emch, Michael E

    2014-09-01

    Interference occurs when the treatment of one person affects the outcome of another. For example, in infectious diseases, whether one individual is vaccinated may affect whether another individual becomes infected or develops disease. Quantifying such indirect (or spillover) effects of vaccination could have important public health or policy implications. In this article we use recently developed inverse-probability weighted (IPW) estimators of treatment effects in the presence of interference to analyze an individually-randomized, placebo-controlled trial of cholera vaccination that targeted 121,982 individuals in Matlab, Bangladesh. Because these IPW estimators have not been employed previously, a simulation study was also conducted to assess the empirical behavior of the estimators in settings similar to the cholera vaccine trial. Simulation study results demonstrate the IPW estimators can yield unbiased estimates of the direct, indirect, total, and overall effects of vaccination when there is interference provided the untestable no unmeasured confounders assumption holds and the group-level propensity score model is correctly specified. Application of the IPW estimators to the cholera vaccine trial indicates the presence of interference. For example, the IPW estimates suggest on average 5.29 fewer cases of cholera per 1000 person-years (95% confidence interval 2.61, 7.96) will occur among unvaccinated individuals within neighborhoods with 60% vaccine coverage compared to neighborhoods with 32% coverage. Our analysis also demonstrates how not accounting for interference can render misleading conclusions about the public health utility of vaccination. © 2014, The International Biometric Society.

  19. Analyzing transmission dynamics of cholera with public health interventions.

    Science.gov (United States)

    Posny, Drew; Wang, Jin; Mukandavire, Zindoga; Modnak, Chairat

    2015-06-01

    Cholera continues to be a serious public health concern in developing countries and the global increase in the number of reported outbreaks suggests that activities to control the diseases and surveillance programs to identify or predict the occurrence of the next outbreaks are not adequate. These outbreaks have increased in frequency, severity, duration and endemicity in recent years. Mathematical models for infectious diseases play a critical role in predicting and understanding disease mechanisms, and have long provided basic insights in the possible ways to control infectious diseases. In this paper, we present a new deterministic cholera epidemiological model with three types of control measures incorporated into a cholera epidemic setting: treatment, vaccination and sanitation. Essential dynamical properties of the model with constant intervention controls which include local and global stabilities for the equilibria are carefully analyzed. Further, using optimal control techniques, we perform a study to investigate cost-effective solutions for time-dependent public health interventions in order to curb disease transmission in epidemic settings. Our results show that the basic reproductive number (R0) remains the model's epidemic threshold despite the inclusion of a package of cholera interventions. For time-dependent controls, the results suggest that these interventions closely interplay with each other, and the costs of controls directly affect the length and strength of each control in an optimal strategy. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. Identification of burden hotspots and risk factors for cholera in India: An observational study.

    Science.gov (United States)

    Ali, Mohammad; Sen Gupta, Sanjukta; Arora, Nisha; Khasnobis, Pradeep; Venkatesh, Srinivas; Sur, Dipika; Nair, Gopinath B; Sack, David A; Ganguly, Nirmal K

    2017-01-01

    Even though cholera has existed for centuries and many parts of the country have sporadic, endemic and epidemic cholera, it is still an under-recognized health problem in India. A Cholera Expert Group in the country was established to gather evidence and to prepare a road map for control of cholera in India. This paper identifies cholera burden hotspots and factors associated with an increased risk of the disease. We acquired district level data on cholera case reports of 2010-2015 from the Integrated Disease Surveillance Program. Socioeconomic characteristics and coverage of water and sanitation was obtained from the 2011 census. Spatial analysis was performed to identify cholera hotspots, and a zero-inflated Poisson regression was employed to identify the factors associated with cholera and predicted case count in the district. 27,615 cholera cases were reported during the 6-year period. Twenty-four of 36 states of India reported cholera during these years, and 13 states were classified as endemic. Of 641 districts, 78 districts in 15 states were identified as "hotspots" based on the reported cases. On the other hand, 111 districts in nine states were identified as "hotspots" from model-based predicted number of cases. The risk for cholera in a district was negatively associated with the coverage of literate persons, households using treated water source and owning mobile telephone, and positively associated with the coverage of poor sanitation and drainage conditions and urbanization level in the district. The study reaffirms that cholera continues to occur throughout a large part of India and identifies the burden hotspots and risk factors. Policymakers may use the findings of the article to develop a roadmap for prevention and control of cholera in India.

  1. An Optimal Cost Effectiveness Study on Zimbabwe Cholera Seasonal Data from 2008–2011

    Science.gov (United States)

    Sardar, Tridip; Mukhopadhyay, Soumalya; Bhowmick, Amiya Ranjan; Chattopadhyay, Joydev

    2013-01-01

    Incidence of cholera outbreak is a serious issue in underdeveloped and developing countries. In Zimbabwe, after the massive outbreak in 2008–09, cholera cases and deaths are reported every year from some provinces. Substantial number of reported cholera cases in some provinces during and after the epidemic in 2008–09 indicates a plausible presence of seasonality in cholera incidence in those regions. We formulate a compartmental mathematical model with periodic slow-fast transmission rate to study such recurrent occurrences and fitted the model to cumulative cholera cases and deaths for different provinces of Zimbabwe from the beginning of cholera outbreak in 2008–09 to June 2011. Daily and weekly reported cholera incidence data were collected from Zimbabwe epidemiological bulletin, Zimbabwe Daily cholera updates and Office for the Coordination of Humanitarian Affairs Zimbabwe (OCHA, Zimbabwe). For each province, the basic reproduction number () in periodic environment is estimated. To the best of our knowledge, this is probably a pioneering attempt to estimate in periodic environment using real-life data set of cholera epidemic for Zimbabwe. Our estimates of agree with the previous estimate for some provinces but differ significantly for Bulawayo, Mashonaland West, Manicaland, Matabeleland South and Matabeleland North. Seasonal trend in cholera incidence is observed in Harare, Mashonaland West, Mashonaland East, Manicaland and Matabeleland South. Our result suggests that, slow transmission is a dominating factor for cholera transmission in most of these provinces. Our model projects cholera cases and cholera deaths during the end of the epidemic in 2008–09 to January 1, 2012. We also determine an optimal cost-effective control strategy among the four government undertaken interventions namely promoting hand-hygiene & clean water distribution, vaccination, treatment and sanitation for each province. PMID:24312540

  2. Cholera: tackling the epidemic in a hostile environment

    Directory of Open Access Journals (Sweden)

    Carlota GONZÁLEZ PÓZEGA

    2015-07-01

    Full Text Available The Painted Veil (2006 is a love story which takes place in the nineteen twenties, between an Englishman, Dr Walter Fane, a bacteriologist, and Kitty, an English upper class girl, who marry for convenience hardly knowing each other. Soon after the wedding they move to Shangai, where Walter is in charge of a government laboratory. Also in Shangai Kitty meets Charles, a married vice consul with whom she has an affair. When Walter discovers that his wife has been unfaithful to him he threatens to divorce her if she refuses to go with him to a village in Inner China, where there is an outbreak of cholera and where his help is required. They settle on the outskirts of Mei?tan?fu. The relationship between Walter and kitty cannot go worse; they hardly talk to each other, and while Walter is working day and night, trying to stop the spread of cholera, Kitty feels lonely and useless . One day she visits a group of French nuns who collaborate in the hospital and run an orphanage, in which Kitty is finally able to help as a music teacher. The fight against cholera is arduous: customs, religion, and politics make the doctor’s work even harder. It is then that Walter and Kitty discover qualities in each other that they did not know of; finally love and reconciliation emerge. When it seems that the outbreak of cholera is already under control, people from downstream villages, where there is no doctor, arrive. Walter feels obliged to set up a refugee camp on the outskirts of the city, where he finally contracts cholera and dies.

  3. Epidemic cholera in rural El Salvador: risk factors in a region covered by a cholera prevention campaign.

    Science.gov (United States)

    Quick, R E; Thompson, B L; Zuniga, A; Dominguez, G; De Brizuela, E L; De Palma, O; Almeida, S; Valencia, A; Ries, A A; Bean, N H

    1995-04-01

    In response to the Latin American cholera epidemic, El Salvador began a prevention programme in April 1991. The first case was confirmed in August, and 700 cases were reported within 3 months. A matched case-control study was conducted in rural La Libertad Department in November 1991. Illness was associated with eating cold cooked or raw seafood (odds ratio [OR] = 7.0; 95% confidence limits [CL] = 1.4, 35.0) and with drinking water outside the home (OR = 8.8; 95% CL = 1.7, 44.6). Assertion of knowledge about how to prevent cholera (OR = 0.2; 95% CL = 0.1, 0.8) and eating rice (OR = 0.2; 95% CL = 0.1, 0.8) were protective. More controls than patients regularly used soap (OR = 0.3; 95% CL = 0.1, 1.0). This study demonstrated three important points for cholera prevention: (1) seafood should be eaten cooked and hot; (2) populations at risk should be taught to treat household drinking water and to avoid drinking water outside the home unless it is known to be treated; and (3) education about hygiene can be an important tool in preventing cholera.

  4. Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries.

    Science.gov (United States)

    Abia, Akebe Luther King; Ubomba-Jaswa, Eunice; Momba, Maggy Ndombo Benteke

    2017-01-01

    Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs) in environmental ctx -negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples) collected from ten sites on the river (January and February 2014) were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA) was the most isolated gene. The cholera toxin (ctxAB) and non-O1 heat-stable (stn/sto) genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

  5. Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae Virulence-Associated Genes: A Potential Trigger for Cholera Outbreaks in Developing Countries

    Directory of Open Access Journals (Sweden)

    Akebe Luther King Abia

    2017-01-01

    Full Text Available Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs in environmental ctx-negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples collected from ten sites on the river (January and February 2014 were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA was the most isolated gene. The cholera toxin (ctxAB and non-O1 heat-stable (stn/sto genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications.

  6. Toxigenic Vibrio cholerae O1 in vegetables and fish raised in wastewater irrigated fields and stabilization ponds during a non-cholera outbreak period in Morogoro, Tanzania

    DEFF Research Database (Denmark)

    Hounmanou, Yaovi M G; Mdegela, Robinson H; Dougnon, Tamègnon V

    2016-01-01

    gene (tcpA) and the haemolysin gene (hlyA). RESULTS: The prevalence of V. cholerae in wastewater, vegetables and fish was 36.7, 21.7 and 23.3 %, respectively. Two isolates from fish gills were V. cholerae O1 and tested positive for ctx and tcpA. One of these contained in addition the hlyA gene while......BACKGROUND: Cholera, one of the world's deadliest infectious diseases, remains rampant and frequent in Tanzania and thus hinders existing control measures. The present study was undertaken to evaluate the occurrence of toxigenic Vibrio cholerae O1 in wastewater, fish and vegetables during a non......-outbreak period in Morogoro, Tanzania. METHODS: From October 2014 to February 2015, 60 wastewater samples, 60 fish samples from sewage stabilization ponds and 60 wastewater irrigated vegetable samples were collected. Samples were cultured for identification of V. cholerae using conventional bacteriological...

  7. Genomic epidemiology of Vibrio cholerae O1 associated with floods, Pakistan, 2010.

    Science.gov (United States)

    Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib; Wren, Brendan W

    2014-01-01

    In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks.

  8. Genomic Epidemiology of Vibrio cholerae O1 Associated with Floods, Pakistan, 2010

    Science.gov (United States)

    Shah, Muhammad Ali; Mutreja, Ankur; Thomson, Nicholas; Baker, Stephen; Parkhill, Julian; Dougan, Gordon; Bokhari, Habib

    2014-01-01

    In August 2010, Pakistan experienced major floods and a subsequent cholera epidemic. To clarify the population dynamics and transmission of Vibrio cholerae in Pakistan, we sequenced the genomes of all V. cholerae O1 El Tor isolates and compared the sequences to a global collection of 146 V. cholerae strains. Within the global phylogeny, all isolates from Pakistan formed 2 new subclades (PSC-1 and PSC-2), lying in the third transmission wave of the seventh-pandemic lineage that could be distinguished by signature deletions and their antimicrobial susceptibilities. Geographically, PSC-1 isolates originated from the coast, whereas PSC-2 isolates originated from inland areas flooded by the Indus River. Single-nucleotide polymorphism accumulation analysis correlated river flow direction with the spread of PSC-2. We found at least 2 sources of cholera in Pakistan during the 2010 epidemic and illustrate the value of a global genomic data bank in contextualizing cholera outbreaks. PMID:24378019

  9. The Population Structure of Vibrio cholerae from the Chandigarh Region of Northern India

    KAUST Repository

    Abd El Ghany, Moataz; Chander, Jagadish; Mutreja, Ankur; Rashid, Mamoon; Hill-Cawthorne, Grant A.; Ali, Shahjahan; Naeem, Raeece; Thomson, Nicholas R.; Dougan, Gordon; Pain, Arnab

    2014-01-01

    Background:Cholera infection continues to be a threat to global public health. The current cholera pandemic associated with Vibrio cholerae El Tor has now been ongoing for over half a century.Methodology/Principal Findings:Thirty-eight V. cholerae El Tor isolates associated with a cholera outbreak in 2009 from the Chandigarh region of India were characterised by a combination of microbiology, molecular typing and whole-genome sequencing. The genomic analysis indicated that two clones of V. cholera circulated in the region and caused disease during this time. These clones fell into two distinct sub-clades that map independently onto wave 3 of the phylogenetic tree of seventh pandemic V. cholerae El Tor. Sequence analyses of the cholera toxin gene, the Vibrio seventh Pandemic Island II (VSPII) and SXT element correlated with this phylogenetic position of the two clades on the El Tor tree. The clade 2 isolates, characterized by a drug-resistant profile and the expression of a distinct cholera toxin, are closely related to the recent V. cholerae isolated elsewhere, including Haiti, but fell on a distinct branch of the tree, showing they were independent outbreaks. Multi-Locus Sequence Typing (MLST) distinguishes two sequence types among the 38 isolates, that did not correspond to the clades defined by whole-genome sequencing. Multi-Locus Variable-length tandem-nucleotide repeat Analysis (MLVA) identified 16 distinct clusters.Conclusions/Significance:The use of whole-genome sequencing enabled the identification of two clones of V. cholerae that circulated during the 2009 Chandigarh outbreak. These clones harboured a similar structure of ICEVchHai1 but differed mainly in the structure of CTX phage and VSPII. The limited capacity of MLST and MLVA to discriminate between the clones that circulated in the 2009 Chandigarh outbreak highlights the value of whole-genome sequencing as a route to the identification of further genetic markers to subtype V. cholerae isolates.

  10. The population structure of Vibrio cholerae from the Chandigarh Region of Northern India.

    Directory of Open Access Journals (Sweden)

    Moataz Abd El Ghany

    2014-07-01

    Full Text Available Cholera infection continues to be a threat to global public health. The current cholera pandemic associated with Vibrio cholerae El Tor has now been ongoing for over half a century.Thirty-eight V. cholerae El Tor isolates associated with a cholera outbreak in 2009 from the Chandigarh region of India were characterised by a combination of microbiology, molecular typing and whole-genome sequencing. The genomic analysis indicated that two clones of V. cholera circulated in the region and caused disease during this time. These clones fell into two distinct sub-clades that map independently onto wave 3 of the phylogenetic tree of seventh pandemic V. cholerae El Tor. Sequence analyses of the cholera toxin gene, the Vibrio seventh Pandemic Island II (VSPII and SXT element correlated with this phylogenetic position of the two clades on the El Tor tree. The clade 2 isolates, characterized by a drug-resistant profile and the expression of a distinct cholera toxin, are closely related to the recent V. cholerae isolated elsewhere, including Haiti, but fell on a distinct branch of the tree, showing they were independent outbreaks. Multi-Locus Sequence Typing (MLST distinguishes two sequence types among the 38 isolates, that did not correspond to the clades defined by whole-genome sequencing. Multi-Locus Variable-length tandem-nucleotide repeat Analysis (MLVA identified 16 distinct clusters.The use of whole-genome sequencing enabled the identification of two clones of V. cholerae that circulated during the 2009 Chandigarh outbreak. These clones harboured a similar structure of ICEVchHai1 but differed mainly in the structure of CTX phage and VSPII. The limited capacity of MLST and MLVA to discriminate between the clones that circulated in the 2009 Chandigarh outbreak highlights the value of whole-genome sequencing as a route to the identification of further genetic markers to subtype V. cholerae isolates.

  11. Investigating the role of water in the Diffusion of Cholera using Agent-Based simulation

    Science.gov (United States)

    Augustijn, Ellen-Wien; Doldersum, Tom; Augustijn, Denie

    2014-05-01

    Traditionally, cholera was considered to be a waterborne disease. Currently we know that many other factors can contribute to the spread of this disease including human mobility and human behavior. However, the hydrological component in cholera diffusion is significant. The interplay between cholera and water includes bacteria (V. cholera) that survive in the aquatic environment, the possibility that run-off water from dumpsites carries the bacteria to surface water (rivers and lakes), and when the bacteria reach streams they can be carried downstream to infect new locations. Modelling is a very important tool to build theory on the interplay between different types of transmission mechanisms that together are responsible for the spread of Cholera. Agent-based simulation models are very suitable to incorporate behavior at individual level and to reproduce emergence. However, it is more difficult to incorporate the hydrological components in this type of model. In this research we present the hydrological component of an Agent-Based Cholera model developed to study a Cholera epidemic in Kumasi (Ghana) in 2005. The model was calibrated on the relative contribution of each community to the distributed pattern of cholera rather than the absolute number of incidences. Analysis of the results shows that water plays an important role in the diffusion of cholera: 75% of the cholera cases were infected via river water that was contaminated by runoff from the dumpsites. To initiate infections upstream, the probability of environment-to-human transmission seemed to be overestimated compared to what may be expected from literature. Scenario analyses show that there is a strong relation between the epidemic curve and the rainfall. Removing dumpsites that are situated close to the river resulted in a strong decrease in the number of cholera cases. Results are sensitive to the scheduling of the daily activities and the survival time of the cholera bacteria.

  12. The Population Structure of Vibrio cholerae from the Chandigarh Region of Northern India

    KAUST Repository

    Abd El Ghany, Moataz

    2014-07-24

    Background:Cholera infection continues to be a threat to global public health. The current cholera pandemic associated with Vibrio cholerae El Tor has now been ongoing for over half a century.Methodology/Principal Findings:Thirty-eight V. cholerae El Tor isolates associated with a cholera outbreak in 2009 from the Chandigarh region of India were characterised by a combination of microbiology, molecular typing and whole-genome sequencing. The genomic analysis indicated that two clones of V. cholera circulated in the region and caused disease during this time. These clones fell into two distinct sub-clades that map independently onto wave 3 of the phylogenetic tree of seventh pandemic V. cholerae El Tor. Sequence analyses of the cholera toxin gene, the Vibrio seventh Pandemic Island II (VSPII) and SXT element correlated with this phylogenetic position of the two clades on the El Tor tree. The clade 2 isolates, characterized by a drug-resistant profile and the expression of a distinct cholera toxin, are closely related to the recent V. cholerae isolated elsewhere, including Haiti, but fell on a distinct branch of the tree, showing they were independent outbreaks. Multi-Locus Sequence Typing (MLST) distinguishes two sequence types among the 38 isolates, that did not correspond to the clades defined by whole-genome sequencing. Multi-Locus Variable-length tandem-nucleotide repeat Analysis (MLVA) identified 16 distinct clusters.Conclusions/Significance:The use of whole-genome sequencing enabled the identification of two clones of V. cholerae that circulated during the 2009 Chandigarh outbreak. These clones harboured a similar structure of ICEVchHai1 but differed mainly in the structure of CTX phage and VSPII. The limited capacity of MLST and MLVA to discriminate between the clones that circulated in the 2009 Chandigarh outbreak highlights the value of whole-genome sequencing as a route to the identification of further genetic markers to subtype V. cholerae isolates.

  13. Role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh.

    Science.gov (United States)

    Islam, M Sirajul; Islam, M Shafiqul; Mahmud, Zahid H; Cairncross, Sandy; Clemens, John D; Collins, Andrew E

    2015-09-01

    In Bangladesh, cholera is endemic and maintains a regular seasonal pattern. The role of phytoplankton in maintaining endemicity and seasonality of cholera was monitored in Matlab, Bangladesh. Phytoplankton and water samples were collected from two ponds bi-weekly for 1 year. The association of Vibrio cholerae O1 with phytoplankton was studied by culture and direct fluorescent antibody techniques. The bio-physicochemical parameters of water were measured and data for cases of cholera were collected from the records of Matlab hospital. The correlation of cholera cases with levels of phytoplankton, V. cholerae and bio-physicochemical parameters of water was carried out using Pearson's correlation coefficients. V. cholerae O1 survived for 48 days in association with Anabaena variabilis in a culturable state, but survived for a year in a viable but non-culturable (VBNC) state. V. cholerae survived for 12 and 32 days in a culturable state in control water (without algae) and water with algae, respectively. There was a significant correlation between changing levels of cholera cases in the community and the blue green algae and total phytoplankton in the aquatic environment. A significant correlation was also found between the cholera cases and chlorophyll-a and VBNC V. cholerae O1 in the aquatic environment. This study demonstrated the role of phytoplankton in maintaining endemicity and seasonality of cholera in Bangladesh. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  14. An outbreak of cholera in Medipally village, Andhra Pradesh, India, 2013

    OpenAIRE

    Uthappa, Chengappa K.; Allam, Ramesh R.; Nalini, Chava; Gunti, Deepak; Udaragudi, Prasada R.; Tadi, Geetha P.; Murhekar, Manoj V.

    2015-01-01

    Background Cholera continues to remain endemic in over 50 countries and has caused large epidemics with around 3?5 million cases occurring every year in Asia alone. In India, cholera is endemic in many states. However, etiological information and age-specific incidence related to cholera outbreaks is limited. In November 2013, district authorities reported a cluster of diarrheal disease among residents of Medipally to the state surveillance unit. We investigated this cluster to confirm its et...

  15. Detection of ctx gene positive non-O1/non-O139 V. cholerae in shrimp aquaculture environments.

    Science.gov (United States)

    Madhusudana, Rao B; Surendran, P K

    2013-06-01

    Water and post-larvae samples from black tiger (Penaeus monodon) shrimp hatcheries; pond water, pond sediment and shrimp from aquaculture farms were screened for the presence of V. cholerae. A V. cholerae-duplex PCR method was developed by utilizing V. cholerae species specific sodB primers and ctxAB genes specific primers. Incidence of V. cholerae was not observed in shrimp hatchery samples but was noticed in aquaculture samples. The incidence of V. cholerae was higher in pond water (7.6%) than in pond sediment (5.2%). Shrimp head (3.6%) portion had relatively higher incidence than shrimp muscle (1.6%). All the V. cholerae isolates (n = 42) belonged to non-O1/non-O139 serogroup, of which 7% of the V. cholerae isolates were potentially cholera-toxigenic (ctx positive). All the ctx positive V. cholerae (n = 3) were isolated from the pond water. Since, cholera toxin (CT) is the major contributing factor for cholera gravis, it is proposed that the mere presence of non-O1/non-O139 V. cholerae need not be the biohazard criterion in cultured black tiger shrimp but only the presence of ctx carrying non-O1/non-O139 V. cholerae may be considered as potential public health risk.

  16. Rainfall mediations in the spreading of epidemic cholera

    Science.gov (United States)

    Righetto, L.; Bertuzzo, E.; Mari, L.; Schild, E.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2013-10-01

    Following the empirical evidence of a clear correlation between rainfall events and cholera resurgence that was observed in particular during the recent outbreak in Haiti, a spatially explicit model of epidemic cholera is re-examined. Specifically, we test a multivariate Poisson rainfall generator, with parameters varying in space and time, as a driver of enhanced disease transmission. The relevance of the issue relates to the key insight that predictive mathematical models may provide into the course of an ongoing cholera epidemic aiding emergency management (say, in allocating life-saving supplies or health care staff) or in evaluating alternative management strategies. Our model consists of a set of dynamical equations (SIRB-like i.e. subdivided into the compartments of Susceptible, Infected and Recovered individuals, and including a balance of Bacterial concentrations in the water reservoir) describing a connected network of human communities where the infection results from the exposure to excess concentrations of pathogens in the water. These, in turn, are driven by rainfall washout of open-air defecation sites or cesspool overflows, hydrologic transport through waterways and by mobility of susceptible and infected individuals. We perform an a posteriori analysis (from the beginning of the epidemic in October 2010 until December 2011) to test the model reliability in predicting cholera cases and in testing control measures, involving vaccination and sanitation campaigns, for the ongoing epidemic. Even though predicting reliably the timing of the epidemic resurgence proves difficult due to rainfall inter-annual variability, we find that the model can reasonably quantify the total number of reported infection cases in the selected time-span. We then run a multi-seasonal prediction of the course of the epidemic until December 2015, to investigate conditions for further resurgences and endemicity of cholera in the region with a view to policies which may bring to

  17. Oral Cancer

    Science.gov (United States)

    Oral cancer can form in any part of the mouth. Most oral cancers begin in the flat cells that cover the ... your mouth, tongue, and lips. Anyone can get oral cancer, but the risk is higher if you are ...

  18. Requirement for Vibrio cholerae integration host factor in conjugative DNA transfer.

    Science.gov (United States)

    McLeod, Sarah M; Burrus, Vincent; Waldor, Matthew K

    2006-08-01

    The requirement for host factors in the transmission of integrative and conjugative elements (ICEs) has not been extensively explored. Here we tested whether integration host factor (IHF) or Fis, two host-encoded nucleoid proteins, are required for transfer of SXT, a Vibrio cholerae-derived ICE that can be transmitted to many gram-negative species. Fis did not influence the transfer of SXT to or from V. cholerae. In contrast, IHF proved to be required for V. cholerae to act as an SXT donor. In the absence of IHF, V. cholerae displayed a modest defect for serving as an SXT recipient. Surprisingly, SXT integration into or excision from the V. cholerae chromosome, which requires an SXT-encoded integrase related to lambda integrase, did not require IHF. Therefore, the defect in SXT transmission in the V. cholerae IHF mutant is probably not related to IHF's ability to promote DNA recombination. The V. cholerae IHF mutant was also highly impaired as a donor of RP4, a broad-host-range conjugative plasmid. Thus, the V. cholerae IHF mutant appears to have a general defect in conjugation. Escherichia coli IHF mutants were not impaired as donors or recipients of SXT or RP4, indicating that IHF is a V. cholerae-specific conjugation factor.

  19. Evaluation of Cholera Toxin Expression in Acidic, Alkaline and Neutral Conditions

    Directory of Open Access Journals (Sweden)

    Narges Rahimi

    2015-02-01

    Full Text Available Background: Cholera is a severe disease which is caused by Vibrio cholerae and it is typically transmitted by either contaminated food or water particularly in developing countries. The most important virulence factor of this bacterium is an enterotoxin called cholera toxin which is a protein complex secreted by the Vibrio cholerae. Objectives: In this project, we determined the production of cholera toxin at different pH values. Materials and Methods: Two standard strain of Vibrio cholerae O1 biovar EL Tor N16961 and Vibrio cholerae O1 biovar Classic ATCC 14035 were used. After overnight cultivation of both the strains the total mRNA extracted and converted to total cDNA. Results: By Relative Real-Time PCR analysis the most cholera toxin production in classical and El Tor strains was at pH 8.5 and 8, respectively. Conclusions: Therefore, We may conclude that use of acidic diet will help in reduction of cholera toxin production.

  20. Hurricanes, climate change and the cholera epidemic in Puerto Rico of 1855-1856.

    Science.gov (United States)

    Christenson, Bernard

    2008-01-01

    Hurricanes and global climate changes may affect the environmental factors of cholera dynamics in warm coastal areas, vulnerable to seasonal or sporadic outbreaks. The cholera epidemic of Puerto Rico in 1855-1856 had a profound effect on the Puerto Rican society; but it was not influenced by any climatic events, such as preceding hurricanes or storms based on past documentary sources. Particularly, the environmental non-toxigenic strains of Vibrio Cholerae in Puerto Rican water sources can maintain their pathogenic potential for sporadic or erratic toxigenic cholera outbreaks--if a "perfect storm" ever occurs.

  1. Molecular Epidemiology of Cholera Outbreaks during the Rainy Season in Mandalay, Myanmar.

    Science.gov (United States)

    Roobthaisong, Amonrattana; Okada, Kazuhisa; Htun, Nilar; Aung, Wah Wah; Wongboot, Warawan; Kamjumphol, Watcharaporn; Han, Aye Aye; Yi, Yi; Hamada, Shigeyuki

    2017-11-01

    Cholera, caused by Vibrio cholerae , remains a global threat to public health. In Myanmar, the availability of published information on the occurrence of the disease is scarce. We report here that cholera incidence in Mandalay generally exhibited a single annual peak, with an annual average of 312 patients with severe dehydration over the past 5 years (since 2011) and was closely associated with the rainy season. We analyzed cholera outbreaks, characterized 67 isolates of V. cholerae serogroup O1 in 2015 from patients from Mandalay, and compared them with 22 V. cholerae O1 isolates (12 from Mandalay and 10 from Yangon) in 2014. The isolates carried the classical cholera toxin B subunit ( ctxB ), the toxin-coregulated pilus A ( tcpA ) of Haitian type, and repeat sequence transcriptional regulator ( rstR ) of El Tor type. Two molecular typing methods, pulsed-field gel electrophoresis and multiple-locus variable-number tandem repeat analysis (MLVA), differentiated the 89 isolates into seven pulsotypes and 15 MLVA profiles. Pulsotype Y15 and one MLVA profile (11, 7, 7, 16, 7) were predominantly found in the isolates from cholera outbreaks in Mandalay, 2015. Pulsotypes Y11, Y12, and Y15 with some MLVA profiles were detected in the isolates from two remote areas, Mandalay and Yangon, with temporal changes. These data suggested that cholera spread from the seaside to the inland area in Myanmar.

  2. Linking Satellite Derived Land Surface Temperature with Cholera: A Case Study for South Sudan

    Science.gov (United States)

    Aldaach, H. S. V.; Jutla, A.; Akanda, A. S.; Colwell, R. R.

    2014-12-01

    A sudden onset of cholera in South Sudan, in April 2014 in Northern Bari in Juba town resulted in more than 400 cholera cases after four weeks of initial outbreak with a case of fatality rate of CFR 5.4%. The total number of reported cholera cases for the period of April to July, 2014 were 5,141 including 114 deaths. With the limited efficacy of cholera vaccines, it is necessary to develop mechanisms to predict cholera occurrence and thereafter devise intervention strategies for mitigating impacts of the disease. Hydroclimatic processes, primarily precipitation and air temperature are related to epidemic and episodic outbreak of cholera. However, due to coarse resolution of both datasets, it is not possible to precisely locate the geographical location of disease. Here, using Land Surface Temperature (LST) from MODIS sensors, we have developed an algorithm to identify regions susceptible for cholera. Conditions for occurrence of cholera were detectable at least one month in advance in South Sudan and were statistically sensitive to hydroclimatic anomalies of land surface and air temperature, and precipitation. Our results indicate significant spatial and temporal averaging required to infer usable information from LST over South Sudan. Preliminary results that geographically location of cholera outbreak was identifiable within 1km resolution of the LST data.

  3. [Cytotoxic effect of Vibrio cholerae non-O1 on Vero cells].

    Science.gov (United States)

    Figueroa-Arredondo, P; García-Lozano, H; Gutiérrez-Cogco, L; Valdespino-Gómez, J L

    1994-01-01

    At the present time there is still in Mexico a diarrhoeal outbreak due to Vibrio cholerae O1. In INDRE we have isolated from the same outbreak last year (jan-apr), 70 strains of Vibrio cholerae Non-O1. These were isolated from patients with a diarrhoeal illness different from cholera. Patients were of different ages and sex, and from various geographic areas. The isolated strains were confirmed by serological agglutination test with polyclonal antisera, and they neither belong to O1 serogroup or O139. We assayed all the 70 strains in Vero cells, searching for cytotoxic effect, probably attributed to cholera toxin, or any other toxin. The strains were screened by PCR for cholera toxin gene detection, and negative results were obtained. We have found only one CT-producer strain, but it was a rough one so, we are not able to affirm that is not a V. cholerae O1 serotype. Vibrio cholerae Non-O1 strains, tested in Vero cells assay, produced cytotoxic effect within 24 h. It was found that 48/70 strains (66.6%), had cytotoxic activity, showing rounding and then lysis of cells. From our results we concluded that this cytotoxic effect, is not cholera toxin related, instead we propose it could be due to an unknown virulence factor, probably a different toxin in mexican Vibrio cholerae Non-O1 strains.

  4. Epidemic waves of cholera in the last two decades in Mozambique.

    Science.gov (United States)

    Langa, José Paulo; Sema, Cynthia; De Deus, Nilsa; Colombo, Mauro Maria; Taviani, Elisa

    2015-07-04

    Africa is increasingly affected by cholera. In Mozambique, cholera appeared in the early 1970s when the seventh pandemic entered Africa from the Indian subcontinent. In the following decades, several epidemics were registered in the country, the 1997-1999 epidemic being the most extended. Since then, Mozambique has been considered an endemic area for cholera, characterized by yearly outbreaks occurring with a seasonal pattern. At least three pandemic variants are thought to have originated in the Indian subcontinent and spread worldwide at different times. To understand the epidemiology of cholera in Mozambique, whether the disease re-emerges periodically or is imported by different routes of transmission, we investigated clinical V. cholerae O1 isolated during 1997-1999 and 2012-2014 epidemics. By detecting and characterizing seven genetic elements, the mobilome profile of each isolate was obtained. By comparing it to known seventh pandemic reference strains, it was possible to discern among different V. cholerae O1 variants active in the country. During 1997-1999, epidemic strains showed two different genetic profiles, both related to a pandemic clone that originated from India and was reported in other African countries in the 1990s. Isolates from 2012-2014 outbreaks showed a genetic background related to the pandemic strains currently active as the prevalent causative agent of cholera worldwide. Despite cholera being endemic in Mozambique, the epidemiology of the disease in the past 20 years has been strongly influenced by the cholera seventh pandemic waves that originated in the Indian subcontinent.

  5. Cholera epidemics of the past offer new insights into an old enemy

    DEFF Research Database (Denmark)

    Phelps, Matthew David; Linnet Perner, Mads; Pitzer, Virginia E

    2018-01-01

    BACKGROUND: Although cholera is considered the quintessential long-cycle waterborne disease, studies have emphasized the existence of short-cycle (food, household) transmission. We investigated singular Danish cholera epidemics (1853) to elucidate epidemiological parameters and modes of spread...... intervals. RESULTS: Epidemics were seeded by travelers from cholera-affected cities; initial transmission chains involving household members and caretakers ensued. Cholera killed 3.4-8.9% of the populations, with highest mortality among seniors (16%) and lowest in children (2.7%). Transmissibility (R0...

  6. Effect of Cholera Toxin Administered Supraspinally or Spinally on the Blood Glucose Level in Pain and D-Glucose Fed Animal Models

    OpenAIRE

    Sim, Yun-Beom; Park, Soo-Hyun; Kang, Yu-Jung; Kim, Sung-Su; Kim, Chea-Ha; Kim, Su-Jin; Jung, Jun-Sub; Ryu, Ohk-Hyun; Choi, Moon-Gi; Choi, Seong-Soo; Suh, Hong-Won

    2013-01-01

    In the present study, the effect of intrathecal (i.t.) or intracerebroventricular (i.c.v.) administration with cholera toxin (CTX) on the blood glucose level was examined in ICR mice. The i.t. treatment with CTX alone for 24 h dose-dependently increased the blood glucose level. However, i.c.v. treatment with CTX for 24 h did not affect the blood glucose level. When mice were orally fed with D-glucose (2 g/kg), the blood glucose level reached to a maximum level at 30 min and almost returned to...

  7. Yemen in a Time of Cholera: Current Situation and Challenges.

    Science.gov (United States)

    Al-Mekhlafi, Hesham M

    2018-03-19

    Since early 2015, Yemen has been in the throes of a grueling civil war, which has devastated the health system and public services, and created one of the world's worst humanitarian disasters. The country is currently facing a cholera epidemic the world's largest on record, surpassing one million (1,061,548) suspected cases, with 2,373 related deaths since October 2016. Cases were first confirmed in Sana'a city and then spread to almost all governorates except Socotra Island. Continued efforts are being made by the World Health Organization and international partners to contain the epidemic through improving water, sanitation and hygiene, setting up diarrhea treatment centers, and improving the population's awareness about the disease. The provision of clean water and adequate sanitation is imperative as an effective long-term solution to prevent the further spread of this epidemic. Cholera vaccination campaigns should also be conducted as a preventive measure.

  8. Epidemic cholera in Latin America: spread and routes of transmission.

    Science.gov (United States)

    Guthmann, J P

    1995-12-01

    In the most recent epidemic of cholera in Latin America, nearly a million cases were reported and almost 9000 people died between January 1991 and December 1993. The epidemic spread rapidly from country to country, affecting in three years all the countries of Latin America except Uruguay and the Caribbean. Case-control studies carried out in Peru showed a significant association between drinking water and risk of disease. Cholera was associated with the consumption of unwashed fruit and vegetables, with eating food from street vendors and with contaminated crabmeat transported in travellers' luggage. This article documents the spread of the epidemic and its routes of transmission and discusses whether the introduction of the epidemic to Peru and its subsequent spread throughout the continent could have been prevented.

  9. OmpU as a biomarker for rapid discrimination between toxigenic and epidemic Vibrio cholerae O1/O139 and non-epidemic Vibrio cholerae in a modified MALDI-TOF MS assay

    NARCIS (Netherlands)

    Paauw, A.; Trip, H.; Niemcewicz, M.; Sellek, R.; Heng, J.M.E.; Mars-Groenendijk, R.H.; Jong, A.L. de; Majchrzykiewicz-Koehorst, J.A.; Olsen, J.S.; Tsivtsivadze, E.

    2014-01-01

    Background Cholera is an acute diarrheal disease caused by Vibrio cholerae. Outbreaks are caused by a genetically homogenous group of strains from serogroup O1 or O139 that are able to produce the cholera toxin. Rapid detection and identification of these epidemic strains is essential for an

  10. Occurrence in Mexico, 1998–2008, of Vibrio cholerae CTX+ El Tor carrying an additional truncated CTX prophage

    OpenAIRE

    Alam, Munirul; Rashed, Shah Manzur; Mannan, Shahnewaj Bin; Islam, Tarequl; Lizarraga-Partida, Marcial Leonardo; Delgado, Gabriela; Morales-Espinosa, Rosario; Mendez, Jose Luis; Navarro, Armando; Watanabe, Haruo; Ohnishi, Makoto; Hasan, Nur A.; Huq, Anwar; Sack, R. Bradley; Colwell, Rita R.

    2014-01-01

    Vibrio cholerae classical (CL) biotype was isolated, along with biotype El Tor (ET) and altered ET carrying the cholera toxin (CTX) gene of CL biotype, during the 1991 cholera epidemic in Mexico, subsequently becoming endemic until 1997. Microbiological, molecular, and phylogenetic analyses of V. cholerae isolated from both clinical and environmental samples during 1998–2008 confirm important genetic events, namely predominance of ET over CL and altered ET in Mexico. Although altered ET is pr...

  11. Comparative genome analysis of non-toxigenic non-O1 versus toxigenic O1 Vibrio cholerae

    OpenAIRE

    Mukherjee, Munmun; Kakarla, Prathusha; Kumar, Sanath; Gonzalez, Esmeralda; Floyd, Jared T.; Inupakutika, Madhuri; Devireddy, Amith Reddy; Tirrell, Selena R.; Bruns, Merissa; He, Guixin; Lindquist, Ingrid E.; Sundararajan, Anitha; Schilkey, Faye D.; Mudge, Joann; Varela, Manuel F.

    2014-01-01

    Pathogenic strains of Vibrio cholerae are responsible for endemic and pandemic outbreaks of the disease cholera. The complete toxigenic mechanisms underlying virulence in Vibrio strains are poorly understood. The hypothesis of this work was that virulent versus non-virulent strains of V. cholerae harbor distinctive genomic elements that encode virulence. The purpose of this study was to elucidate genomic differences between the O1 serotypes and non-O1 V. cholerae PS15, a non-toxigenic strain,...

  12. Inhibition of Retinoblastoma Protein Inactivation

    Science.gov (United States)

    2017-11-01

    CONTRACT NUMBER Inhibition of Retinoblastoma Protein Inactivation 5b. GRANT NUMBER W81XWH-14-1-0329 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Seth M...confirmed 108 compounds as giving a dose-response curve with at least 30% inhibition at 10 µM. The flowchart of hit progression is shown on the...Cancer Research Program under Award No. W81XWH-14-1-0329 to S.M.R. Opinions, interpretations, conclusions, and recommendations are those of the author

  13. Epidemiological characteristics of an institutional outbreak of cholera.

    Science.gov (United States)

    Goh, K T; Lam, S; Ling, M K

    1987-01-01

    An outbreak of cholera caused by Vibrio cholerae 01, biotype El Tor, serotype Inaba, phage type 4, occurred in an institution for the aged in Singapore in August and September 1984. 96 inmates were infected (21 symptomatic and 75 asymptomatic) and 5 died. The index case was a 72-year-old male inmate who continued to assist in food preparation in the kitchen from the time of onset of diarrhoea until he was seriously ill and hospitalized 4 days later. Another kitchen helper was found to have asymptomatic V. cholerae 01 infection. The infection rate for males was significantly higher than that for females (P less than 0.025), associated with the use of unsanitary toilets. The main mode of transmission was through food contaminated by the 2 kitchen helpers who probably accounted for most of the infections, while poor personal hygiene of the inmates helped to sustain person-to-person spread. The outbreak was confined within the institution as the result of the prompt and effective implementation of control measures.

  14. Cholera in Mexico: the paradoxical benefits of the last pandemic.

    Science.gov (United States)

    Sepúlveda, Jaime; Valdespino, José Luis; García-García, Lourdes

    2006-01-01

    To describe the impact of preventive and control measures in Mexico prior to, and during, the cholera epidemic of 1991-2001. When cholera appeared in Latin America in January 1991, the Mexican government considered that it represented a national security problem. Therefore, actions were implemented within the health sector (e.g. epidemiological surveillance, laboratory network and patient care) and other sectors (public education and basic sanitation). The first case occurred in Mexico in June 1991. The incidence rate remained below 17.9 per 100,000 inhabitants and affected mainly rural areas. The last cholera report occurred in 2001. The disease never became endemic. The population benefited not only from acquisition of knowledge about preventive measures, but also from modification of risky practices and from reinforcement of city and municipal drinking water supplies. Control strategies had an overall impact in decreasing diarrheal mortality among children under five years of age. Additionally the country did not suffer from a decrease in tourism or economic consequences. This experience can be considered as the operationalization of a new public health system spanning multisectorial activities, involving community participation, political will and with impact on public health and economic issues.

  15. El Niño, Rainfall, and the Shifting Geography of Cholera in Africa

    Science.gov (United States)

    Moore, S.; Azman, A. S.; Zaitchik, B. F.; McKay, H.; Lessler, J.

    2017-12-01

    The El Niño Southern Oscillation (ENSO) and other climate patterns can have profound impacts on the occurrence of infectious diseases. Because of the key role of water supplies in cholera transmission, a relationship between El Niño events and cholera incidence is highly plausible, and previous research has shown a link between El Niño patterns and cholera in Bangladesh. However, there is little systematic evidence for this link in Africa where many cholera cases and deaths are reported. To understand how ENSO affects the geographic distribution of cholera incidence in Africa, we used a hierarchical Bayesian approach to integrate over 17,000 annual observations of cholera incidence from 2000-2014 in over 3,000 unique locations of varying spatial extent, ranging from entire countries to neighborhoods. The resulting maps reflect modeled cholera incidence at a fine spatial resolution using reported counts of cholera cases, key explanatory variables, and a spatially-dependent covariance term. We then examined the potential mechanistic association between ENSO-related changes in cholera incidence and several environmental variables including rainfall. El Niño profoundly changed the annual geographic distribution of cholera in Africa from 2000-2014, shifting the burden to continental East Africa, where almost 50,000 additional cases occur during El Niño years. Cholera incidence during El Niño years was higher in regions of East Africa with increased rainfall, but incidence was also higher in some areas with decreased rainfall suggesting a complex relationship between rainfall and cholera incidence. Here we show clear evidence for a shift in the distribution of cholera incidence throughout Africa in El Niño and non-El Niño years, likely mediated by El Niño's impact on local climatic factors. Knowledge of this relationship between cholera and climate patterns coupled with El Niño forecasting could be used to notify countries in Africa when they are likely to see

  16. Association between earthquake events and cholera outbreaks: a cross-country 15-year longitudinal analysis.

    Science.gov (United States)

    Sumner, Steven A; Turner, Elizabeth L; Thielman, Nathan M

    2013-12-01

    Large earthquakes can cause population displacement, critical sanitation infrastructure damage, and increased threats to water resources, potentially predisposing populations to waterborne disease epidemics such as cholera. Problem The risk of cholera outbreaks after earthquake disasters remains uncertain. A cross-country analysis of World Health Organization (WHO) cholera data that would contribute to this discussion has yet to be published. A cross-country longitudinal analysis was conducted among 63 low- and middle-income countries from 1995-2009. The association between earthquake disasters of various effect sizes and a relative spike in cholera rates for a given country was assessed utilizing fixed-effects logistic regression and adjusting for gross domestic product per capita, water and sanitation level, flooding events, percent urbanization, and under-five child mortality. Also, the association between large earthquakes and cholera rate increases of various degrees was assessed. Forty-eight of the 63 countries had at least one year with reported cholera infections during the 15-year study period. Thirty-six of these 48 countries had at least one earthquake disaster. In adjusted analyses, country-years with ≥10,000 persons affected by an earthquake had 2.26 times increased odds (95 CI, 0.89-5.72, P = .08) of having a greater than average cholera rate that year compared to country-years having earthquake. The association between large earthquake disasters and cholera infections appeared to weaken as higher levels of cholera rate increases were tested. A trend of increased risk of greater than average cholera rates when more people were affected by an earthquake in a country-year was noted. However these findings did not reach statistical significance at traditional levels and may be due to chance. Frequent large-scale cholera outbreaks after earthquake disasters appeared to be relatively uncommon.

  17. Seasonality of cholera from 1974 to 2005: a review of global patterns

    Directory of Open Access Journals (Sweden)

    Feldacker Caryl

    2008-06-01

    Full Text Available Abstract Background The seasonality of cholera is described in various study areas throughout the world. However, no study examines how temporal cycles of the disease vary around the world or reviews its hypothesized causes. This paper reviews the literature on the seasonality of cholera and describes its temporal cycles by compiling and analyzing 32 years of global cholera data. This paper also provides a detailed literature review on regional patterns and environmental and climatic drivers of cholera patterns. Data, Methods, and Results Cholera data are compiled from 1974 to 2005 from the World Health Organization Weekly Epidemiological Reports, a database that includes all reported cholera cases in 140 countries. The data are analyzed to measure whether season, latitude, and their interaction are significantly associated with the country-level number of outbreaks in each of the 12 preceding months using separate negative binomial regression models for northern, southern, and combined hemispheres. Likelihood ratios tests are used to determine the model of best fit. The results suggest that cholera outbreaks demonstrate seasonal patterns in higher absolute latitudes, but closer to the equator, cholera outbreaks do not follow a clear seasonal pattern. Conclusion The findings suggest that environmental and climatic factors partially control the temporal variability of cholera. These results also indirectly contribute to the growing debate about the effects of climate change and global warming. As climate change threatens to increase global temperature, resulting rises in sea levels and temperatures may influence the temporal fluctuations of cholera, potentially increasing the frequency and duration of cholera outbreaks.

  18. Serum and mucosal immune responses to an inactivated influenza virus vaccine induced by epidermal powder immunization.

    Science.gov (United States)

    Chen, D; Periwal, S B; Larrivee, K; Zuleger, C; Erickson, C A; Endres, R L; Payne, L G

    2001-09-01

    Both circulating and mucosal antibodies are considered important for protection against infection by influenza virus in humans and animals. However, current inactivated vaccines administered by intramuscular injection using a syringe and needle elicit primarily circulating antibodies. In this study, we report that epidermal powder immunization (EPI) via a unique powder delivery system elicits both serum and mucosal antibodies to an inactivated influenza virus vaccine. Serum antibody responses to influenza vaccine following EPI were enhanced by codelivery of cholera toxin (CT), a synthetic oligodeoxynucleotide containing immunostimulatory CpG motifs (CpG DNA), or the combination of these two adjuvants. In addition, secretory immunoglobulin A (sIgA) antibodies were detected in the saliva and mucosal lavages of the small intestine, trachea, and vaginal tract, although the titers were much lower than the IgG titers. The local origin of the sIgA antibodies was further shown by measuring antibodies released from cultured tracheal and small intestinal fragments and by detecting antigen-specific IgA-secreting cells in the lamina propria using ELISPOT assays. EPI with a single dose of influenza vaccine containing CT or CT and CpG DNA conferred complete protection against lethal challenges with an influenza virus isolated 30 years ago, whereas a prime and boost immunizations were required for protection in the absence of an adjuvant. The ability to elicit augmented circulating antibody and mucosal antibody responses makes EPI a promising alternative to needle injection for administering vaccines against influenza and other diseases.

  19. Expression of the Native Cholera Toxin B Subunit Gene and Assembly as Functional Oligomers in Transgenic Tobacco Chloroplasts

    Science.gov (United States)

    Daniell, Henry; Lee, Seung-Bum; Panchal, Tanvi; Wiebe, Peter O.

    2012-01-01

    The B subunits of enterotoxigenic Escherichia coli (LTB) and cholera toxin of Vibrio cholerae (CTB) are candidate vaccine antigens. Integration of an unmodified CTB-coding sequence into chloroplast genomes (up to 10,000 copies per cell), resulted in the accumulation of up to 4.1% of total soluble tobacco leaf protein as functional oligomers (410-fold higher expression levels than that of the unmodified LTB gene expressed via the nuclear genome). However, expresssion levels reported are an underestimation of actual accumulation of CTB in transgenic chloroplasts, due to aggregation of the oligomeric forms in unboiled samples similar to the aggregation observed for purified bacterial antigen. PCR and Southern blot analyses confirmed stable integration of the CTB gene into the chloroplast genome. Western blot analysis showed that the chloroplast-synthesized CTB assembled into oligomers and were antigenically identical with purified native CTB. Also, binding assays confirmed that chloroplast- synthesized CTB binds to the intestinal membrane GM1-ganglioside receptor, indicating correct folding and disulfide bond formation of CTB pentamers within transgenic chloroplasts. In contrast to stunted nuclear transgenic plants, chloroplast transgenic plants were morphologically indistinguishable from untransformed plants, when CTB was constitutively expressed in chloroplasts. Introduced genes were inherited stably in subsequent generations, as confirmed by PCR and Southern blot analyses. Increased production of an efficient transmucosal carrier molecule and delivery system, like CTB, in transgenic chloroplasts makes plant-based oral vaccines and fusion proteins with CTB needing oral administration commercially feasible. Successful expression of foreign genes in transgenic chromoplasts and availability of marker-free chloroplast transformation techniques augurs well for development of vaccines in edible parts of transgenic plants. Furthermore, since the quaternary structure of

  20. Increased jejunal prostaglandin E2 concentrations in patients with acute cholera

    NARCIS (Netherlands)

    Speelman, P.; Rabbani, G. H.; Bukhave, K.; Rask-Madsen, J.

    1985-01-01

    Supraphysiologic doses of prostaglandins (PGs) mimic the effect of cholera toxin and cAMP in the small intestine, but not all observations are explicable in terms of the theory that links PGs to cAMP. Because no data exist on endogenous PGs in human cholera we measured PGE2 concentrations in jejunal

  1. Environmental factor analysis of cholera in China using remote sensing and geographical information systems.

    Science.gov (United States)

    Xu, M; Cao, C X; Wang, D C; Kan, B; Xu, Y F; Ni, X L; Zhu, Z C

    2016-04-01

    Cholera is one of a number of infectious diseases that appears to be influenced by climate, geography and other natural environments. This study analysed the environmental factors of the spatial distribution of cholera in China. It shows that temperature, precipitation, elevation, and distance to the coastline have significant impact on the distribution of cholera. It also reveals the oceanic environmental factors associated with cholera in Zhejiang, which is a coastal province of China, using both remote sensing (RS) and geographical information systems (GIS). The analysis has validated the correlation between indirect satellite measurements of sea surface temperature (SST), sea surface height (SSH) and ocean chlorophyll concentration (OCC) and the local number of cholera cases based on 8-year monthly data from 2001 to 2008. The results show the number of cholera cases has been strongly affected by the variables of SST, SSH and OCC. Utilizing this information, a cholera prediction model has been established based on the oceanic and climatic environmental factors. The model indicates that RS and GIS have great potential for designing an early warning system for cholera.

  2. Cholera Incidence and Mortality in Sub-Saharan African Sites during Multi-country Surveillance.

    Science.gov (United States)

    Sauvageot, Delphine; Njanpop-Lafourcade, Berthe-Marie; Akilimali, Laurent; Anne, Jean-Claude; Bidjada, Pawou; Bompangue, Didier; Bwire, Godfrey; Coulibaly, Daouda; Dengo-Baloi, Liliana; Dosso, Mireille; Orach, Christopher Garimoi; Inguane, Dorteia; Kagirita, Atek; Kacou-N'Douba, Adele; Keita, Sakoba; Kere Banla, Abiba; Kouame, Yao Jean-Pierre; Landoh, Dadja Essoya; Langa, Jose Paulo; Makumbi, Issa; Miwanda, Berthe; Malimbo, Muggaga; Mutombo, Guy; Mutombo, Annie; NGuetta, Emilienne Niamke; Saliou, Mamadou; Sarr, Veronique; Senga, Raphael Kakongo; Sory, Fode; Sema, Cynthia; Tante, Ouyi Valentin; Gessner, Bradford D; Mengel, Martin A

    2016-05-01

    Cholera burden in Africa remains unknown, often because of weak national surveillance systems. We analyzed data from the African Cholera Surveillance Network (www.africhol.org). During June 2011-December 2013, we conducted enhanced surveillance in seven zones and four outbreak sites in Togo, the Democratic Republic of Congo (DRC), Guinea, Uganda, Mozambique and Cote d'Ivoire. All health facilities treating cholera cases were included. Cholera incidences were calculated using culture-confirmed cholera cases and culture-confirmed cholera cases corrected for lack of culture testing usually due to overwhelmed health systems and imperfect test sensitivity. Of 13,377 reported suspected cases, 34% occurred in Conakry, Guinea, 47% in Goma, DRC, and 19% in the remaining sites. From 0-40% of suspected cases were aged under five years and from 0.3-86% had rice water stools. Within surveillance zones, 0-37% of suspected cases had confirmed cholera compared to 27-38% during outbreaks. Annual confirmed incidence per 10,000 population was cholera incidence, age distribution, clinical presentation, culture confirmation, and testing frequency. These results can help guide preventive activities, including vaccine use.

  3. Characterization of a clinical Vibrio cholerae O139 isolate from Mexico.

    Science.gov (United States)

    Parveen, Salina; Farrah, Samuel R; Gonzalez-Bonilla, Celia; Zamudio, Altagracia V; Tamplin, Mark L

    2003-01-01

    Pathogenic strains of Vibrio cholerae O139 possess the cholera toxin A subunit (ctxA) gene as well as the gene for toxin co-regulated pili (tcpA). We report the isolation of a ctxA-negative, tcpA-negative V. cholerae O139 strain (INDREI) from a patient in Mexico diagnosed with gastrointestinal illness. Certain phenotypic characteristics of this strain were identical to those of V. cholerae O1 biotype El Tor. Unlike ctxA-positive V. cholerae O139 strains, this strain was sensitive to a wide panel of antibiotics, including ampicillin, chloramphenicol, ciprofloxacin, gentamicin, furazolidone, nalidixic acid, nitrofurantoin, tetracycline, trimethoprim-sulfamethoxazole, and streptomycin, but was resistant to polymyxin B. Ribotype and pulsed-field gel electrophoresis profiles of INDRE1 differed from those of ctxA-positive V. cholerae O139 and other V. cholerae strains. Phenotypic characteristics of the Mexico strain were similar to those reported for V. cholerae O139 isolates from Argentina and Sri Lanka.

  4. Genome Sequence of Vibrio cholerae Strain O1 Ogawa El Tor, Isolated in Mexico, 2013

    OpenAIRE

    Díaz-Quiñonez, José Alberto; Hernández-Monroy, Irma; López-Martínez, Irma; Ortiz-Alcántara, Joanna; González-Durán, Elizabeth; Ruiz-Matus, Cuitláhuac; Kuri-Morales, Pablo; Ramírez-González, José Ernesto

    2014-01-01

    We present the draft genome sequence of Vibrio cholerae InDRE 3140 recovered in 2013 during a cholera outbreak in Mexico. The genome showed the Vibrio 7th pandemic islands VSP1 and VSP2, the pathogenic islands VPI-1 and VPI-2, the integrative and conjugative element SXT/R391 (ICE-SXT), and both prophages CTXφ and RS1φ.

  5. Potential Future Risk of Cholera Due to Climate Change in Northern ...

    African Journals Online (AJOL)

    Prof

    Cholera is one of the infectious diseases that remains a major health burden in ... this is because many factors that influence are these diseases (both climatic ... condition, education, and poverty reduction may reduce the risk of contracting cholera ... Research Organization in collaboration .... The dots on top represent the.

  6. A highly specific phage defense system is a conserved feature of the Vibrio cholerae mobilome.

    Directory of Open Access Journals (Sweden)

    Brendan J O'Hara

    2017-06-01

    Full Text Available Vibrio cholerae-specific bacteriophages are common features of the microbial community during cholera infection in humans. Phages impose strong selective pressure that favors the expansion of phage-resistant strains over their vulnerable counterparts. The mechanisms allowing virulent V. cholerae strains to defend against the ubiquitous threat of predatory phages have not been established. Here, we show that V. cholerae PLEs (phage-inducible chromosomal island-like elements are widespread genomic islands dedicated to phage defense. Analysis of V. cholerae isolates spanning a 60-year collection period identified five unique PLEs. Remarkably, we found that all PLEs (regardless of geographic or temporal origin respond to infection by a myovirus called ICP1, the most prominent V. cholerae phage found in cholera patient stool samples from Bangladesh. We found that PLE activity reduces phage genome replication and accelerates cell lysis following ICP1 infection, killing infected host cells and preventing the production of progeny phage. PLEs are mobilized by ICP1 infection and can spread to neighboring cells such that protection from phage predation can be horizontally acquired. Our results reveal that PLEs are a persistent feature of the V. cholerae mobilome that are adapted to providing protection from a single predatory phage and advance our understanding of how phages influence pathogen evolution.

  7. A highly specific phage defense system is a conserved feature of the Vibrio cholerae mobilome.

    Science.gov (United States)

    O'Hara, Brendan J; Barth, Zachary K; McKitterick, Amelia C; Seed, Kimberley D

    2017-06-01

    Vibrio cholerae-specific bacteriophages are common features of the microbial community during cholera infection in humans. Phages impose strong selective pressure that favors the expansion of phage-resistant strains over their vulnerable counterparts. The mechanisms allowing virulent V. cholerae strains to defend against the ubiquitous threat of predatory phages have not been established. Here, we show that V. cholerae PLEs (phage-inducible chromosomal island-like elements) are widespread genomic islands dedicated to phage defense. Analysis of V. cholerae isolates spanning a 60-year collection period identified five unique PLEs. Remarkably, we found that all PLEs (regardless of geographic or temporal origin) respond to infection by a myovirus called ICP1, the most prominent V. cholerae phage found in cholera patient stool samples from Bangladesh. We found that PLE activity reduces phage genome replication and accelerates cell lysis following ICP1 infection, killing infected host cells and preventing the production of progeny phage. PLEs are mobilized by ICP1 infection and can spread to neighboring cells such that protection from phage predation can be horizontally acquired. Our results reveal that PLEs are a persistent feature of the V. cholerae mobilome that are adapted to providing protection from a single predatory phage and advance our understanding of how phages influence pathogen evolution.

  8. Satellite Based Assessment of Hydroclimatic Conditions Related to Cholera in Zimbabwe.

    Directory of Open Access Journals (Sweden)

    Antarpreet Jutla

    Full Text Available Cholera, an infectious diarrheal disease, has been shown to be associated with large scale hydroclimatic processes. The sudden and sporadic occurrence of epidemic cholera is linked with high mortality rates, in part, due to uncertainty in timing and location of outbreaks. Improved understanding of the relationship between pathogenic abundance and climatic processes allows prediction of disease outbreak to be an achievable goal. In this study, we show association of large scale hydroclimatic processes with the cholera epidemic in Zimbabwe reported to have begun in Chitungwiza, a city in Mashonaland East province, in August, 2008.Climatic factors in the region were found to be associated with triggering cholera outbreak and are shown to be related to anomalies of temperature and precipitation, validating the hypothesis that poor conditions of sanitation, coupled with elevated temperatures, and followed by heavy rainfall can initiate outbreaks of cholera. Spatial estimation by satellite of precipitation and global gridded air temperature captured sensitivities in hydroclimatic conditions that permitted identification of the location in the region where the disease outbreak began.Satellite derived hydroclimatic processes can be used to capture environmental conditions related to epidemic cholera, as occurred in Zimbabwe, thereby providing an early warning system. Since cholera cannot be eradicated because the causative agent, Vibrio cholerae, is autochthonous to the aquatic environment, prediction of conditions favorable for its growth and estimation of risks of triggering the disease in a given population can be used to alert responders, potentially decreasing infection and saving lives.

  9. Structural organization of the transfer RNA operon I of Vibrio cholerae

    Indian Academy of Sciences (India)

    Nine major transfer RNA (tRNA) gene clusters were analysed in various Vibrio cholerae strains. Of these, only the tRNA operon I was found to differ significantly in V. cholerae classical (sixth pandemic) and El Tor (seventh pandemic) strains. Amongst the sixteen tRNA genes contained in this operon, genes for tRNA Gln3 ...

  10. Model of Cholera Forecasting Using Artificial Neural Network in Chabahar City, Iran

    Directory of Open Access Journals (Sweden)

    Zahra Pezeshki

    2016-02-01

    Full Text Available Background: Cholera as an endemic disease remains a health issue in Iran despite decrease in incidence. Since forecasting epidemic diseases provides appropriate preventive actions in disease spread, different forecasting methods including artificial neural networks have been developed to study parameters involved in incidence and spread of epidemic diseases such as cholera. Objectives: In this study, cholera in rural area of Chabahar, Iran was investigated to achieve a proper forecasting model. Materials and Methods: Data of cholera was gathered from 465 villages, of which 104 reported cholera during ten years period of study. Logistic regression modeling and correlate bivariate were used to determine risk factors and achieve possible predictive model one-hidden-layer perception neural network with backpropagation training algorithm and the sigmoid activation function was trained and tested between the two groups of infected and non-infected villages after preprocessing. For determining validity of prediction, the ROC diagram was used. The study variables included climate conditions and geographical parameters. Results: After determining significant variables of cholera incidence, the described artificial neural network model was capable of forecasting cholera event among villages of test group with accuracy up to 80%. The highest accuracy was achieved when model was trained with variables that were significant in statistical analysis describing that the two methods confirm the result of each other. Conclusions: Application of artificial neural networking assists forecasting cholera for adopting protective measures. For a more accurate prediction, comprehensive information is required including data on hygienic, social and demographic parameters.

  11. Hierarchical Bayesian modeling of the space - time diffusion patterns of cholera epidemic in Kumasi, Ghana

    NARCIS (Netherlands)

    Osei, Frank B.; Osei, F.B.; Duker, Alfred A.; Stein, A.

    2011-01-01

    This study analyses the joint effects of the two transmission routes of cholera on the space-time diffusion dynamics. Statistical models are developed and presented to investigate the transmission network routes of cholera diffusion. A hierarchical Bayesian modelling approach is employed for a joint

  12. Vibrio cholerae O1 secretes an extracellular matrix in response to antibody-mediated agglutination.

    Directory of Open Access Journals (Sweden)

    Danielle E Baranova

    Full Text Available Vibrio cholerae O1 is one of two serogroups responsible for epidemic cholera, a severe watery diarrhea that occurs after the bacterium colonizes the human small intestine and secretes a potent ADP-ribosylating toxin. Immunity to cholera is associated with intestinal anti-lipopolysaccharide (LPS antibodies, which are known to inhibit V. cholerae motility and promote bacterial cell-cell crosslinking and aggregation. Here we report that V. cholerae O1 classical and El Tor biotypes produce an extracellular matrix (ECM when forcibly immobilized and agglutinated by ZAC-3 IgG, an intestinally-derived monoclonal antibody (MAb against the core/lipid A region of LPS. ECM secretion, as demonstrated by crystal violet staining and scanning electron microscopy, occurred within 30 minutes of antibody exposure and peaked by 3 hours. Non-motile mutants of V. cholerae did not secrete ECM following ZAC-3 IgG exposure, even though they were susceptible to agglutination. The ECM was enriched in O-specific polysaccharide (OSP but not Vibrio polysaccharide (VPS. Finally, we demonstrate that ECM production by V. cholerae in response to ZAC-3 IgG was associated with bacterial resistant to a secondary complement-mediated attack. In summary, we propose that V. cholerae O1, upon encountering anti-LPS antibodies in the intestinal lumen, secretes an ECM (or O-antigen capsule possibly as a strategy to shield itself from additional host immune factors and to exit an otherwise inhospitable host environment.

  13. Oral Tolerance: Therapeutic Implications for Autoimmune Diseases

    Directory of Open Access Journals (Sweden)

    Ana M. C. Faria

    2006-01-01

    Full Text Available Oral tolerance is classically defined as the suppression of immune responses to antigens (Ag that have been administered previously by the oral route. Multiple mechanisms of tolerance are induced by oral Ag. Low doses favor active suppression, whereas higher doses favor clonal anergy/deletion. Oral Ag induces Th2 (IL-4/IL-10 and Th3 (TGF-β regulatory T cells (Tregs plus CD4+CD25+ regulatory cells and LAP+T cells. Induction of oral tolerance is enhanced by IL-4, IL-10, anti-IL-12, TGF-β, cholera toxin B subunit (CTB, Flt-3 ligand, anti-CD40 ligand and continuous feeding of Ag. In addition to oral tolerance, nasal tolerance has also been shown to be effective in suppressing inflammatory conditions with the advantage of a lower dose requirement. Oral and nasal tolerance suppress several animal models of autoimmune diseases including experimental allergic encephalomyelitis (EAE, uveitis, thyroiditis, myasthenia, arthritis and diabetes in the nonobese diabetic (NOD mouse, plus non-autoimmune diseases such as asthma, atherosclerosis, colitis and stroke. Oral tolerance has been tested in human autoimmune diseases including MS, arthritis, uveitis and diabetes and in allergy, contact sensitivity to DNCB, nickel allergy. Positive results have been observed in phase II trials and new trials for arthritis, MS and diabetes are underway. Mucosal tolerance is an attractive approach for treatment of autoimmune and inflammatory diseases because of lack of toxicity, ease of administration over time and Ag-specific mechanism of action. The successful application of oral tolerance for the treatment of human diseases will depend on dose, developing immune markers to assess immunologic effects, route (nasal versus oral, formulation, mucosal adjuvants, combination therapy and early therapy.

  14. The Role of Socioeconomic Status in Longitudinal Trends of Cholera in Matlab, Bangladesh, 1993–2007

    Science.gov (United States)

    Root, Elisabeth Dowling; Rodd, Joshua; Yunus, Mohammad; Emch, Michael

    2013-01-01

    There has been little evidence of a decline in the global burden of cholera in recent years as the number of cholera cases reported to WHO continues to rise. Cholera remains a global threat to public health and a key indicator of lack of socioeconomic development. Overall socioeconomic development is the ultimate solution for control of cholera as evidenced in developed countries. However, most research has focused on cross-county comparisons so that the role of individual- or small area-level socioeconomic status (SES) in cholera dynamics has not been carefully studied. Reported cases of cholera in Matlab, Bangladesh have fluctuated greatly over time and epidemic outbreaks of cholera continue, most recently with the introduction of a new serotype into the region. The wealth of longitudinal data on the population of Matlab provides a unique opportunity to explore the impact of socioeconomic status and other demographic characteristics on the long-term temporal dynamics of cholera in the region. In this population-based study we examine which factors impact the initial number of cholera cases in a bari at the beginning of the 0139 epidemic and the factors impacting the number of cases over time. Cholera data were derived from the ICDDR,B health records and linked to socioeconomic and geographic data collected as part of the Matlab Health and Demographic Surveillance System. Longitudinal zero-inflated Poisson (ZIP) multilevel regression models are used to examine the impact of environmental and socio-demographic factors on cholera counts across baris. Results indicate that baris with a high socioeconomic status had lower initial rates of cholera at the beginning of the 0139 epidemic (γ01 = −0.147, p = 0.041) and a higher probability of reporting no cholera cases (α01 = 0.156, p = 0.061). Populations in baris characterized by low SES are more likely to experience higher cholera morbidity at the beginning of an epidemic than populations in high SES

  15. The role of socioeconomic status in longitudinal trends of cholera in Matlab, Bangladesh, 1993-2007.

    Science.gov (United States)

    Root, Elisabeth Dowling; Rodd, Joshua; Yunus, Mohammad; Emch, Michael

    2013-01-01

    There has been little evidence of a decline in the global burden of cholera in recent years as the number of cholera cases reported to WHO continues to rise. Cholera remains a global threat to public health and a key indicator of lack of socioeconomic development. Overall socioeconomic development is the ultimate solution for control of cholera as evidenced in developed countries. However, most research has focused on cross-county comparisons so that the role of individual- or small area-level socioeconomic status (SES) in cholera dynamics has not been carefully studied. Reported cases of cholera in Matlab, Bangladesh have fluctuated greatly over time and epidemic outbreaks of cholera continue, most recently with the introduction of a new serotype into the region. The wealth of longitudinal data on the population of Matlab provides a unique opportunity to explore the impact of socioeconomic status and other demographic characteristics on the long-term temporal dynamics of cholera in the region. In this population-based study we examine which factors impact the initial number of cholera cases in a bari at the beginning of the 0139 epidemic and the factors impacting the number of cases over time. Cholera data were derived from the ICDDR,B health records and linked to socioeconomic and geographic data collected as part of the Matlab Health and Demographic Surveillance System. Longitudinal zero-inflated Poisson (ZIP) multilevel regression models are used to examine the impact of environmental and socio-demographic factors on cholera counts across baris. Results indicate that baris with a high socioeconomic status had lower initial rates of cholera at the beginning of the 0139 epidemic (γ(01) = -0.147, p = 0.041) and a higher probability of reporting no cholera cases (α(01) = 0.156, p = 0.061). Populations in baris characterized by low SES are more likely to experience higher cholera morbidity at the beginning of an epidemic than populations in high

  16. Radiobiological inactivation of Epstein-Barr virus

    International Nuclear Information System (INIS)

    Henderson, E.; Heston, L.; Grogan, E.; Miller, G.

    1978-01-01

    Lymphocyte transforming properties of B95-8 strain Epstein-Barr virus (EBV) are very sensitive to inactivation by either uv or x irradiation. No dose of irradiation increases the transforming capacity of EBV. The x-ray dose needed for inactivation of EBV transformation (dose that results in 37% survival, 60,000 rads) is similar to the dose required for inactivation of plaque formation by herpes simplex virus type 1 (Fischer strain). Although herpes simplex virus is more sensitive than EBV to uv irradiation, this difference is most likely due to differences in the kinetics or mechanisms of repair of uv damage to the two viruses. The results lead to the hypothesis that a large part, or perhaps all, of the EBV genome is in some way needed to initiate transformation. The abilities of EBV to stimulate host cell DNA synthesis, to induce nuclear antigen, and to immortalize are inactivated in parallel. All clones of marmoset cells transformed by irradiated virus produce extracellular transforming virus. These findings suggest that the abilities of the virus to transform and to replicate complete progeny are inactivated together. The amounts of uv and x irradiation that inactivate transformation by B95-8 virus are less than the dose needed to inactivate early antigen induction by the nontransforming P 3 HR-1 strain of EBV. Based on radiobiological inactivation, 10 to 50% of the genome is needed for early antigen induction

  17. Prevalence and characterization of Vibrio cholerae isolated from shrimp products imported into Denmark

    DEFF Research Database (Denmark)

    Dalsgaard, A.; Bjergskov, T.; Jeppesen, V.F.

    1996-01-01

    A total of 3,555 metric tonnes of warm water shrimp were imported into Denmark from December 1994 to July 1995. V. cholerae O1 was not detected in any of the 748 samples analyzed. Non-Ol V. cholerae was found in a single (0.1%) cooked frozen shrimp product and in five (0.7%) raw frozen products......, all originating from shrimp produced in aquaculture. Six isolated strains agglutinated in polyvalent O antisera, but did not agglutinate in Ogawa or Inaba antisera. The six strains were resistant to colistin and sulfisoxazole; three strains also showed resistance to ampicillin. None of the strains...... contained plasmids or genes encoding cholera toxin (CT) or heat-stable enterotoxin (NAG-ST), The absence of V. cholerae O1 and the low number of samples containing CT and NAG-ST negative non-Ol strains in imported shrimp suggest that I! cholerae in such products may not constitute a public health problem....

  18. A study on the geophylogeny of clinical and environmental Vibrio cholerae in Kenya.

    Directory of Open Access Journals (Sweden)

    John Kiiru

    Full Text Available Cholera remains a significant public health challenge in many sub-Saharan countries including Kenya. We have performed a combination of phylogenetic and phenotypic analysis based on whole genome DNA sequences derived from 40 environmental and 57 clinical V. cholerae from different regions of Kenya isolated between 2005 and 2010. Some environmental and all clinical isolates mapped back onto wave three of the monophyletic seventh pandemic V. cholerae El Tor phylogeny but other environmental isolates were phylogenetically very distinct. Thus, the genomes of the Kenyan V. cholerae O1 El Tor isolates are clonally related to other El Tor V. cholerae isolated elsewhere in the world and similarly harbour antibiotic resistance-associated STX elements. Further, the Kenyan O1 El Tor isolates fall into two distinct clades that may have entered Kenya independently.

  19. Improved laboratory capacity is required to respond better to future cholera outbreaks in Papua New Guinea

    Directory of Open Access Journals (Sweden)

    Paul Horwood

    2012-05-01

    Full Text Available Cholera was first detected in Papua New Guinea in July 2009, caused by Vibrio cholerae O1 El Tor serotype Ogawa. By late 2011, 15 500 cases had been reported throughout lowland Papua New Guinea with a case fatality rate of 3.2%. The epidemic has since slowed, with only sporadic cases reported in Western Province and the Autonomous Region of Bougainville (ARB. Accurate and timely diagnosis is a critical element of the public health response to cholera, yet in low-income countries where the burden of cholera is the greatest, diagnostic services are often limited. Here we report on the diagnostic challenges and the logistical factors that impacted on diagnosis during the first reported outbreak of cholera in Papua New Guinea.

  20. [GM1-dot-EIA for the detection of toxin-producing Vibrio cholerae strains].

    Science.gov (United States)

    Markina, O V; Alekseeva, L P; Telesmanich, N R; Chemisova, O S; Akulova, M V; Markin, N V

    2011-05-01

    A new variant of enzyme immunoassay (EIA) has been developed on the basis of GM1 gangliosides to detect the toxin-producing Vibrio cholerae strains--GM1-dot-EIA. Experiments were run using a nitrocellulose membrane to bind GM1 gangliosides and polyclonal antitoxic serum to detect cholerogen. GM1-dot-EIA testing identified cholera toxin in 11 of 13 supernatants of V. cholerae eltor ctx(+) strains isolated from man and in 3 of 7 supernatants of V. cholerae eltor ctx(+) strains isolated from water. These data agree with those obtained in CM1-EIA. There was no reaction with the supernatants of other microorganisms. The sensitivity of the technique was 10 ng/ml. Thus, the simple and specific GM1-dot-EIA may be recommended to detect toxin-producing V cholerae strains isolated from man and water.

  1. Biofilm formation and phenotypic variation enhance predation-driven persistence of Vibrio cholerae

    DEFF Research Database (Denmark)

    Matz, Carsten; McDougald, D.; Moreno, A.M.

    2005-01-01

    Persistence of the opportunistic bacterial pathogen Vibrio cholerae in aquatic environments is the principal cause for seasonal occurrence of cholera epidemics. This causality has been explained by postulating that V. cholerae forms biofilms in association with animate and inanimate surfaces....... Alternatively, it has been proposed that bacterial pathogens are an integral part of the natural microbial food web and thus their survival is constrained by protozoan predation. Here, we report that both explanations are interrelated. our data show that biofilms are the protective agent enabling V. cholerae...... to survive protozoan grazing while their planktonic counterparts are eliminated. Grazing on planktonic V. cholerae was found to select for the biofilm-enhancing rugose phase variant, which is adapted to the surf ace-associated niche by the production of exopolymers. Interestingly, grazing resistance in V...

  2. Predictors of disease severity in patients admitted to a cholera treatment center in urban Haiti.

    Science.gov (United States)

    Valcin, Claude-Lyne; Severe, Karine; Riche, Claudia T; Anglade, Benedict S; Moise, Colette Guiteau; Woodworth, Michael; Charles, Macarthur; Li, Zhongze; Joseph, Patrice; Pape, Jean W; Wright, Peter F

    2013-10-01

    Cholera, previously unrecognized in Haiti, spread through the country in the fall of 2010. An analysis was performed to understand the epidemiological characteristics, clinical management, and risk factors for disease severity in a population seen at the GHESKIO Cholera Treatment Center in Port-au-Prince. A comprehensive review of the medical records of patients admitted during the period of October 28, 2010-July 10, 2011 was conducted. Disease severity on admission was directly correlated with older age, more prolonged length of stay, and presentation during the two epidemic waves seen in the observation period. Although there was a high seroprevalence of human immunodeficiency virus (HIV), severity of cholera was not greater with HIV infection. This study documents the correlation of cholera waves with rainfall and its reduction in settings with improved sanitary conditions and potable water when newly introduced cholera affects all ages equally so that interventions must be directed throughout the population.

  3. Photodynamic Inactivation of Mammalian Viruses and Bacteriophages

    Directory of Open Access Journals (Sweden)

    Liliana Costa

    2012-06-01

    Full Text Available Photodynamic inactivation (PDI has been used to inactivate microorganisms through the use of photosensitizers. The inactivation of mammalian viruses and bacteriophages by photosensitization has been applied with success since the first decades of the last century. Due to the fact that mammalian viruses are known to pose a threat to public health and that bacteriophages are frequently used as models of mammalian viruses, it is important to know and understand the mechanisms and photodynamic procedures involved in their photoinactivation. The aim of this review is to (i summarize the main approaches developed until now for the photodynamic inactivation of bacteriophages and mammalian viruses and, (ii discuss and compare the present state of the art of mammalian viruses PDI with phage photoinactivation, with special focus on the most relevant mechanisms, molecular targets and factors affecting the viral inactivation process.

  4. Genotypic and PFGE/MLVA analyses of Vibrio cholerae O1: geographical spread and temporal changes during the 2007-2010 cholera outbreaks in Thailand.

    Directory of Open Access Journals (Sweden)

    Kazuhisa Okada

    Full Text Available BACKGROUND: Vibrio cholerae O1 El Tor dominated the seventh cholera pandemic which occurred in the 1960s. For two decades, variants of V. cholerae O1 El Tor that produce classical cholera toxin have emerged and spread globally, replacing the prototypic El Tor biotype. This study aims to characterize V. cholerae O1 isolates from outbreaks in Thailand with special reference to genotypic variations over time. METHODS/FINDINGS: A total of 343 isolates of V. cholerae O1 from cholera outbreaks from 2007 to 2010 were investigated, and 99.4% were found to carry the classical cholera toxin B subunit (ctxB and El Tor rstR genes. Pulsed-field gel electrophoresis (PFGE differentiated the isolates into 10 distinct pulsotypes, clustered into two major groups, A and B, with an overall similarity of 88%. Ribotyping, multiple-locus variable-number tandem-repeat analysis (MLVA, and PCR to detect Vibrio seventh pandemic island II (VSP-II related genes of randomly selected isolates from each pulsotype corresponded to the results obtained by PFGE. Epidemiological investigations revealed that MLVA type 2 was strongly associated with a cholera outbreak in northeastern Thailand in 2007, while MLVA type 7 dominated the outbreaks of the southern Gulf areas in 2009 and MLVA type 4 dominated the outbreaks of the central Gulf areas during 2009-2010. Only MLVA type 16 isolates were found in a Thai-Myanmar border area in 2010, whereas those of MLVA types 26, 39, and 41 predominated this border area in 2008. Type 39 then disappeared 1-2 years later as MLVA type 41 became prevalent. Type 41 was also found to infect an outbreak area. CONCLUSIONS: MLVA provided a high-throughput genetic typing tool for understanding the in-depth epidemiology of cholera outbreaks. Our epidemiological surveys suggest that some clones of V. cholerae O1 with similar but distinctive genetic traits circulate in outbreak sites, while others disappear over time.

  5. Risk Map of Cholera Infection for Vaccine Deployment: The Eastern Kolkata Case

    Science.gov (United States)

    You, Young Ae; Ali, Mohammad; Kanungo, Suman; Sah, Binod; Manna, Byomkesh; Puri, Mahesh; Nair, G. Balakrish; Bhattacharya, Sujit Kumar; Convertino, Matteo; Deen, Jacqueline L.; Lopez, Anna Lena; Wierzba, Thomas F.; Clemens, John; Sur, Dipika

    2013-01-01

    Background Despite advancement of our knowledge, cholera remains a public health concern. During March-April 2010, a large cholera outbreak afflicted the eastern part of Kolkata, India. The quantification of importance of socio-environmental factors in the risk of cholera, and the calculation of the risk is fundamental for deploying vaccination strategies. Here we investigate socio-environmental characteristics between high and low risk areas as well as the potential impact of vaccination on the spatial occurrence of the disease. Methods and Findings The study area comprised three wards of Kolkata Municipal Corporation. A mass cholera vaccination campaign was conducted in mid-2006 as the part of a clinical trial. Cholera cases and data of the trial to identify high risk areas for cholera were analyzed. We used a generalized additive model (GAM) to detect risk areas, and to evaluate the importance of socio-environmental characteristics between high and low risk areas. During the one-year pre-vaccination and two-year post-vaccination periods, 95 and 183 cholera cases were detected in 111,882 and 121,827 study participants, respectively. The GAM model predicts that high risk areas in the west part of the study area where the outbreak largely occurred. High risk areas in both periods were characterized by poor people, use of unsafe water, and proximity to canals used as the main drainage for rain and waste water. Cholera vaccine uptake was significantly lower in the high risk areas compared to low risk areas. Conclusion The study shows that even a parsimonious model like GAM predicts high risk areas where cholera outbreaks largely occurred. This is useful for indicating where interventions would be effective in controlling the disease risk. Data showed that vaccination decreased the risk of infection. Overall, the GAM-based risk map is useful for policymakers, especially those from countries where cholera remains to be endemic with periodic outbreaks. PMID:23936491

  6. Cholera in the United States, 1965-1991. Risks at home and abroad.

    Science.gov (United States)

    Weber, J T; Levine, W C; Hopkins, D P; Tauxe, R V

    1994-03-14

    To assess risks for cholera in the United States. Review of published reports of cholera outbreaks and sporadic cases and Centers for Disease Control and Prevention (CDC) memoranda and laboratory reports. Persons with symptomatic laboratory-diagnosed cholera treated in the United States and territories. From 1965 through 1991, 136 cases of cholera were reported. Fifty-three percent of the patients were hospitalized and three persons died (case-fatality rate, 0.02). Ninety-three infections were acquired in the United States and 42 overseas; for one case the source was unknown. Domestically acquired cholera was largely related to the endemic Gulf Coast focus of Vibrio cholerae 01 (56 cases). The major domestic food vehicle was shellfish, particularly crabs harvested from the Gulf of Mexico or nearby estuaries. In 1991, 14 (54%) of 26 domestically acquired cases were caused by food from Ecuador (n = 11) and Thailand (n = 3). During 1991, the first cases of cholera in travelers returning from South America were reported. In 1991, the rate of cholera among air travelers returning from South America was estimated as 0.3 per 100,000; among air travelers returning from Ecuador, 2.6 per 100,000. Cholera remains a small but persistent risk in the United States and for travelers. An endemic focus on the Gulf Coast, the continuing global pandemic, and the epidemic in South America make this likely to continue for years to come. Physicians should know how to diagnose and treat cholera and should report all suspected cases to their state health departments.

  7. Human Mobility Patterns and Cholera Epidemics: a Spatially Explicit Modeling Approach

    Science.gov (United States)

    Mari, L.; Bertuzzo, E.; Righetto, L.; Casagrandi, R.; Gatto, M.; Rodriguez-Iturbe, I.; Rinaldo, A.

    2010-12-01

    Cholera is an acute enteric disease caused by the ingestion of water or food contaminated by the bacterium Vibrio cholerae. Although most infected individuals do not develop severe symptoms, their stool may contain huge quantities of V.~cholerae cells. Therefore, while traveling or commuting, asymptomatic carriers can be responsible for the long-range dissemination of the disease. As a consequence, human mobility is an alternative and efficient driver for the spread of cholera, whose primary propagation pathway is hydrological transport through river networks. We present a multi-layer network model that accounts for the interplay between epidemiological dynamics, hydrological transport and long-distance dissemination of V.~cholerae due to human movement. In particular, building on top of state-of-the-art spatially explicit models for cholera spread through surface waters, we describe human movement and its effects on the propagation of the disease by means of a gravity-model approach borrowed from transportation theory. Gravity-like contact processes have been widely used in epidemiology, because they can satisfactorily depict human movement when data on actual mobility patterns are not available. We test our model against epidemiological data recorded during the cholera outbreak occurred in the KwaZulu-Natal province of South Africa during years 2000--2001. We show that human mobility does actually play an important role in the formation of the spatiotemporal patterns of cholera epidemics. In particular, long-range human movement may determine inter-catchment dissemination of V.~cholerae cells, thus in turn explaining the emergence of epidemic patterns that cannot be produced by hydrological transport alone. We also show that particular attention has to be devoted to study how heterogeneously distributed drinking water supplies and sanitation conditions may affect cholera transmission.

  8. Climate and infectious disease: use of remote sensing for detection of Vibrio cholerae by indirect measurement

    Science.gov (United States)

    Lobitz, B.; Beck, L.; Huq, A.; Wood, B.; Fuchs, G.; Faruque, A. S.; Colwell, R.

    2000-01-01

    It has long been known that cholera outbreaks can be initiated when Vibrio cholerae, the bacterium that causes cholera, is present in drinking water in sufficient numbers to constitute an infective dose, if ingested by humans. Outbreaks associated with drinking or bathing in unpurified river or brackish water may directly or indirectly depend on such conditions as water temperature, nutrient concentration, and plankton production that may be favorable for growth and reproduction of the bacterium. Although these environmental parameters have routinely been measured by using water samples collected aboard research ships, the available data sets are sparse and infrequent. Furthermore, shipboard data acquisition is both expensive and time-consuming. Interpolation to regional scales can also be problematic. Although the bacterium, V. cholerae, cannot be sensed directly, remotely sensed data can be used to infer its presence. In the study reported here, satellite data were used to monitor the timing and spread of cholera. Public domain remote sensing data for the Bay of Bengal were compared directly with cholera case data collected in Bangladesh from 1992-1995. The remote sensing data included sea surface temperature and sea surface height. It was discovered that sea surface temperature shows an annual cycle similar to the cholera case data. Sea surface height may be an indicator of incursion of plankton-laden water inland, e.g., tidal rivers, because it was also found to be correlated with cholera outbreaks. The extensive studies accomplished during the past 25 years, confirming the hypothesis that V. cholerae is autochthonous to the aquatic environment and is a commensal of zooplankton, i.e., copepods, when combined with the findings of the satellite data analyses, provide strong evidence that cholera epidemics are climate-linked.

  9. Cholera epidemics, war and disasters around Goma and Lake Kivu: an eight-year survey.

    Directory of Open Access Journals (Sweden)

    Didier Bompangue

    Full Text Available BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants and South Kivu (4,670,121 inhabitants from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9. Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.

  10. Molecular insights into the evolutionary pathway of Vibrio cholerae O1 atypical El Tor variants.

    Science.gov (United States)

    Kim, Eun Jin; Lee, Dokyung; Moon, Se Hoon; Lee, Chan Hee; Kim, Sang Jun; Lee, Jae Hyun; Kim, Jae Ouk; Song, Manki; Das, Bhabatosh; Clemens, John D; Pape, Jean William; Nair, G Balakrish; Kim, Dong Wook

    2014-09-01

    Pandemic V. cholerae strains in the O1 serogroup have 2 biotypes: classical and El Tor. The classical biotype strains of the sixth pandemic, which encode the classical type cholera toxin (CT), have been replaced by El Tor biotype strains of the seventh pandemic. The prototype El Tor strains that produce biotype-specific cholera toxin are being replaced by atypical El Tor variants that harbor classical cholera toxin. Atypical El Tor strains are categorized into 2 groups, Wave 2 and Wave 3 strains, based on genomic variations and the CTX phage that they harbor. Whole-genome analysis of V. cholerae strains in the seventh cholera pandemic has demonstrated gradual changes in the genome of prototype and atypical El Tor strains, indicating that atypical strains arose from the prototype strains by replacing the CTX phages. We examined the molecular mechanisms that effected the emergence of El Tor strains with classical cholera toxin-carrying phage. We isolated an intermediary V. cholerae strain that carried two different CTX phages that encode El Tor and classical cholera toxin, respectively. We show here that the intermediary strain can be converted into various Wave 2 strains and can act as the source of the novel mosaic CTX phages. These results imply that the Wave 2 and Wave 3 strains may have been generated from such intermediary strains in nature. Prototype El Tor strains can become Wave 3 strains by excision of CTX-1 and re-equipping with the new CTX phages. Our data suggest that inter-chromosomal recombination between 2 types of CTX phages is possible when a host bacterial cell is infected by multiple CTX phages. Our study also provides molecular insights into population changes in V. cholerae in the absence of significant changes to the genome but by replacement of the CTX prophage that they harbor.

  11. Research Protocol - Cholera and pregnancy in Haiti: description of pregnant patients presenting to MSF OCA cholera treatment centers, September 2011-December 2013.

    OpenAIRE

    Schillberg, Erin; Bryson, Lindsay; Pierre, Grand; Lenglet, Annick

    2015-01-01

    Principal objective To understand the demographic, clinical and outcome profiles of pregnant patients that presented with cholera infection to Figaro CTC and CRUO CTU between September 2011 and December 2013. Specific objectives 1. To determine the clinical presentation, treatment regimens and outcomes of pregnant patients with cholera seen at Figaro CTC and CRUO CTU between September 2011 and December 2014; 2. To identify factors related to age, clinical presentation or treatmen...

  12. Oral myiasis

    Directory of Open Access Journals (Sweden)

    Thalaimalai Saravanan

    2015-01-01

    Full Text Available Myiasis is a pathologic condition in humans occurring because of parasitic infestation. Parasites causing myiasis belong to the order Diptera. Oral myiasis is seen secondary to oral wounds, suppurative lesions, and extraction wounds, especially in individuals with neurological deficit. In such cases, neglected oral hygiene and halitosis attracts the flies to lay eggs in oral wounds resulting in oral myiasis. We present a case of oral myiasis in 40-year-old male patient with mental disability and history of epilepsy.

  13. Analysis of a cholera toxin B subunit (CTB) and human mucin 1 (MUC1) conjugate protein in a MUC1-tolerant mouse model.

    Science.gov (United States)

    Pinkhasov, Julia; Alvarez, M Lucrecia; Pathangey, Latha B; Tinder, Teresa L; Mason, Hugh S; Walmsley, Amanda M; Gendler, Sandra J; Mukherjee, Pinku

    2010-12-01

    Since epithelial mucin 1 (MUC1) is associated with several adenocarcinomas at the mucosal sites, it is pertinent to test the efficacy of a mucosally targeted vaccine formulation. The B subunit of the Vibrio cholerae cholera toxin (CTB) has great potential to act as a mucosal carrier for subunit vaccines. In the present study we evaluated whether a MUC1 tandem repeat (TR) peptide chemically linked to CTB would break self-antigen tolerance in the transgenic MUC1-tolerant mouse model (MUC1.Tg) through oral or parenteral immunizations. We report that oral immunization with the CTB-MUC1 conjugate along with mucosal adjuvant, unmethylated CpG oligodeoxynucleotide (ODN) and interleukin-12 (IL-12) did not break self-antigen tolerance in MUC1.Tg mice, but induced a strong humoral response in wild-type C57BL/6 mice. However, self-antigen tolerance in the MUC1.Tg mouse model was broken after parenteral immunizations with different doses of the CTB-MUC1 conjugate protein and with the adjuvant CpG ODN co-delivered with CTB-MUC1. Importantly, mice immunized systemically with CpG ODN alone and with CTB-MUC1 exhibited decreased tumor burden when challenged with a mammary gland tumor cell line that expresses human MUC1.

  14. Analysis of a Cholera Toxin B Subunit (CTB) and Human Mucin 1 (MUC1) Conjugate Protein in a MUC1 Tolerant Mouse Model

    Science.gov (United States)

    Pinkhasov, Julia; Alvarez, M. Lucrecia; Pathangey, Latha B.; Tinder, Teresa L.; Mason, Hugh S.; Walmsley, Amanda M.; Gendler, Sandra J.; Mukherjee, Pinku

    2011-01-01

    Since epithelial mucin 1 (MUC1) is associated with several adenocarcinomas at mucosal sites, it is pertinent to test the efficacy of a mucosally targeted vaccine formulation. The B subunit of the Vibrio cholerae cholera toxin (CTB) has great potential to act as a mucosal carrier for subunit vaccines. In the present study we evaluated whether a MUC1 tandem repeat (TR) peptide chemically linked to CTB would break self-antigen tolerance in the transgenic MUC1 tolerant mouse model (MUC1.Tg) through oral or parenteral immunizations. We report that oral immunization with the CTB-MUC1 conjugate along with mucosal adjuvant, unmethylated CpG oligodeoxynucleotide (ODN) and interleukin-12 (IL-12), did not break self-antigen tolerance in MUC1.Tg mice, but induced a strong humoral response in wild-type C57BL/6 mice. However, self-antigen tolerance in the MUC1.Tg mouse model was broken after parenteral immunizations with different doses of the CTB-MUC1 conjugate protein and with the adjuvant CpG ODN co-delivered with CTB-MUC1. Importantly, mice immunized systemically with CpG ODN alone and with CTB-MUC1 exhibited decreased tumor burden when challenged with a mammary gland tumor cell line that expresses human MUC1. PMID:20824430

  15. The DnaK Chaperone Uses Different Mechanisms To Promote and Inhibit Replication of Vibrio cholerae Chromosome 2

    Directory of Open Access Journals (Sweden)

    Jyoti K. Jha

    2017-04-01

    Full Text Available Replication of Vibrio cholerae chromosome 2 (Chr2 depends on molecular chaperone DnaK to facilitate binding of the initiator (RctB to the replication origin. The binding occurs at two kinds of site, 12-mers and 39-mers, which promote and inhibit replication, respectively. Here we show that DnaK employs different mechanisms to enhance the two kinds of binding. We found that mutations in rctB that reduce DnaK binding also reduce 12-mer binding and initiation. The initiation defect is suppressed by second-site mutations that increase 12-mer binding only marginally. Instead, they reduce replication inhibitory mechanisms: RctB dimerization and 39-mer binding. One suppressing change was in a dimerization domain which is folded similarly to the initiator of an iteron plasmid—the presumed progenitor of Chr2. In plasmids, DnaK promotes initiation by reducing dimerization. A different mutation was in the 39-mer binding domain of RctB and inactivated it, indicating an alternative suppression mechanism. Paradoxically, although DnaK increases 39-mer binding, the increase was also achieved by inactivating the DnaK binding site of RctB. This result suggests that the site inhibits the 39-mer binding domain (via autoinhibition when prevented from binding DnaK. Taken together, our results reveal an important feature of the transition from plasmid to chromosome: the Chr2 initiator retains the plasmid-like dimerization domain and its control by chaperones but uses the chaperones in an unprecedented way to control the inhibitory 39-mer binding.

  16. The "cholera cloud" in the nineteenth-century "British World": history of an object-without-an-essence.

    Science.gov (United States)

    Mukharji, Projit Bihari

    2012-01-01

    The "cholera cloud" is one of the most persistent presences in the archives of nineteenth-century cholera in the "British World." Yet it has seldom received anything more than a passing acknowledgment from historians of cholera. Tracing the history of the cholera cloud as an object promises to open up a new dimension of the historically contingent experience of cholera, as well as make a significant contribution to the emergent literature on "thing theory." By conceptualizing the cholera cloud as an object-without-an-essence, this article demonstrates how global cholera pandemics in the nineteenth century produced globalized objects in which a near-universal recognizability and an utterly context-specific set of meanings, visions, and realities could ironically cohabit.

  17. [DETERMINATION OF TYPES OF EPIDEMIC MANIFESTATIONS OF CHOLERA IN REGIONS OF THE CRIMEA FEDERAL DISTRICT (REPUBLIC OF CRIMEA)].

    Science.gov (United States)

    Onischenko, G G; Popova, A Yu; Moskvitina, E A; Penkovskaya, N A; Listopad, S A; Titova, S V; Kruglikov, V D

    2015-01-01

    The aim of the study was determination of the type of epidemic manifestations of cholera in the Republic of Crimea based on evaluation of epidemic manifestations of cholera risk of introduction and spread of the infection. It was concluded, that, based on the cholera outbreaks, that had taken place, contamination of surface water bodies (fresh and sea) and sewage by Vibrio cholerae O1 ctxA+ and Vibrio cholerae O1 ctXA- potential epidemic danger of introduction of the infection by various types of international transport, population migration, the presence of epidemiologic risk in realization of water pathway of transmission of cholera causative agent and several other social conditions, the Republic of Crimea remains in the group of territories of type I by epidemic manifestations of cholera.

  18. Assessment of Photodynamic Inactivation against Periodontal Bacteria Mediated by a Chitosan Hydrogel in a 3D Gingival Model

    OpenAIRE

    Po-Chun Peng; Chien-Ming Hsieh; Chueh-Pin Chen; Tsuimin Tsai; Chin-Tin Chen

    2016-01-01

    Chitosan hydrogels containing hydroxypropyl methylcellulose (HPMC) and toluidine blue O were prepared and assessed for their mucoadhesive property and antimicrobial efficacy of photodynamic inactivation (PDI). Increased HPMC content in the hydrogels resulted in increased mucoadhesiveness. Furthermore, we developed a simple In Vitro 3D gingival model resembling the oral periodontal pocket to culture the biofilms of Staphylococcus aureus (S. aureus), Aggregatibacter actinomycetemcomitans (A. ac...

  19. Oral cancer

    Science.gov (United States)

    Cancer - mouth; Mouth cancer; Head and neck cancer; Squamous cell cancer - mouth; Malignant neoplasm - oral ... National Cancer Institute. PDQ lip and oral cavity cancer ... September 25, 2015. www.cancer.gov/types/head-and-neck/hp/lip- ...

  20. Oral Ketamine

    African Journals Online (AJOL)

    Oral Ketamine: A Four-years Experience in ... Key words: Oral Ketamine, Premedication and Oncology. .... form of a letter published in 19835. .... Acta. Anaesthesiol Scandinavica, 1998; 42: 750-758. 4. Murray P. Substitution of another opioid ...

  1. Biocompatible capped iron oxide nanoparticles for Vibrio cholerae detection

    International Nuclear Information System (INIS)

    Sharma, Anshu; Rawat, Kamla; Solanki, Pratima R; Bohidar, H B; Baral, Dinesh

    2015-01-01

    We report the studies relating to fabrication of an efficient immunosensor for Vibrio cholerae detection. Magnetite (iron oxide (Fe 3 O 4 )) nanoparticles (NPs) have been synthesized by the co-precipitation method and capped by citric acid (CA). These NPs were electrophoretically deposited onto indium-tin-oxide (ITO)-coated glass substrate and used for immobilization of monoclonal antibodies against Vibrio cholerae (Ab) and bovine serum albumin (BSA) for Vibrio cholerae detection using an electrochemical technique. The structural and morphological studies of Fe 3 O 4 and CA-Fe 3 O 4 /ITO were characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and dynamic light scattering (DLS) techniques. The average crystalline size of Fe 3 O 4 , CA-Fe 3 O 4 nanoparticles obtained were about 29 ± 1 nm and 37 ± 1 nm, respectively. The hydrodynamic radius of the nanoparticles was found to be 77.35 nm (Fe 3 O 4 ) and 189.51 nm (CA-Fe 3 O 4 ) by DLS measurement. The results of electrochemical response studies of the fabricated BSA/Ab/CA-Fe 2 O 3 /ITO immunosensor exhibits a good detection range of 12.5–500 ng mL −1 with a low detection limit of 0.32 ng mL −1 , sensitivity 0.03 Ω/ng ml −1 cm −2 , and reproducibility more than 11 times. (paper)

  2. Twin outbreak of cholera in rural North Karnataka, India

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    Shuchismita Dey

    2014-01-01

    Full Text Available Background & objectives: Successive outbreaks of acute watery diarrhoea occurred in Talikoti and Harnal, located in Bijapur District of the southern Indian s0 tate of Karnataka, in July and August 2012, respectively. These outbreaks were investigated to identify the aetiology and epidemiology. Methods: Information was collected from the local population and health centres. Stool and water samples were collected from the admitted patients and their drinking water sources. Standard microbiological and PCR techniques were employed for isolation and characterization of the pathogen. Results: While 101 people (0.38% were affected in Talikoti, 200 (20.94% were affected in Harnal which is a small remote village. All age groups were affected but no death occurred. While the outbreak was smaller, longer and apparently spread by person to person contact in Talikoti, it occurred as a single source flash outbreak at Harnal. A single clone of toxigenic Vibrio cholerae O1 Ogawa biotype El Tor was isolated from the two stool samples obtained from Talikoti and subsequently from three of five stool samples obtained from Harnal indicating village to village spread of the aetiological agent. Striking similarity in antibiotic resistance profiles of these isolates with a particular strain isolated from the city of Belgaum, 250 km away, in 2010, prompted tracking the lineage of the V. cholerae isolates by DNA fingerprinting. Random amplified polymorphic DNA (RAPD fingerprinting assay helped confirm the origin of the incriminating strain to Belgaum. Interpretation & conclusions: Our study reported the first twin outbreak of cholera in two remote areas of Bijapur district, Karnataka, south India. It also indicated the need for immediate preparedness to deal with such emergencies.

  3. Skewed X-inactivation in cloned mice

    International Nuclear Information System (INIS)

    Senda, Sho; Wakayama, Teruhiko; Yamazaki, Yukiko; Ohgane, Jun; Hattori, Naka; Tanaka, Satoshi; Yanagimachi, Ryuzo; Shiota, Kunio

    2004-01-01

    In female mammals, dosage compensation for X-linked genes is accomplished by inactivation of one of two X chromosomes. The X-inactivation ratio (a percentage of the cells with inactivated maternal X chromosomes in the whole cells) is skewed as a consequence of various genetic mutations, and has been observed in a number of X-linked disorders. We previously reported that phenotypically normal full-term cloned mouse fetuses had loci with inappropriate DNA methylation. Thus, cloned mice are excellent models to study abnormal epigenetic events in mammalian development. In the present study, we analyzed X-inactivation ratios in adult female cloned mice (B6C3F1). Kidneys of eight naturally produced controls and 11 cloned mice were analyzed. Although variations in X-inactivation ratio among the mice were observed in both groups, the distributions were significantly different (Ansary-Bradley test, P < 0.01). In particular, 2 of 11 cloned mice showed skewed X-inactivation ratios (19.2% and 86.8%). Similarly, in intestine, 1 of 10 cloned mice had a skewed ratio (75.7%). Skewed X-inactivation was observed to various degrees in different tissues of different individuals, suggesting that skewed X-inactivation in cloned mice is the result of secondary cell selection in combination with stochastic distortion of primary choice. The present study is the first demonstration that skewed X-inactivation occurs in cloned animals. This finding is important for understanding both nuclear transfer technology and etiology of X-linked disorders

  4. The three-dimensional crystal structure of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L.; Nance, S.; Spangler, B.D. [Argonne National Lab., IL (United States); Scott, D.L. [Yale Univ., New Haven, CT (United States). Dept. of Molecular Biophysics and Biochemistry; Westbrook, E.M. [Northwestern Univ., Evanston, IL (United States)

    1996-02-01

    The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB{sub 5} enterotoxin (choleragen). We have solved the three-dimensional structure of choleragen at 2.5 {Angstrom} resolution and compared the refined coordinates with those of choleragenoid (isolated B pentamer) and the heat-labile enterotoxin from Escherichia coli (LT). The crystalline coordinates provide a detailed view of the stereochemistry implicated in binding to GM1 gangliosides and in carrying out ADP-ribosylation. The A2 chain of choleragen, in contrast to that of LT, is a nearly continuous {alpha}-helix with an interpretable carboxyl tail.

  5. Highly diverse recombining populations of Vibrio cholerae and Vibrio parahaemolyticus in French Mediterranean coastal lagoons

    Directory of Open Access Journals (Sweden)

    Kevin eEsteves

    2015-07-01

    Full Text Available Vibrio parahaemolyticus and Vibrio cholerae are ubiquitous to estuarine and marine environments. These two species can induce infections in humans. Therefore understanding the structure and dynamics of non-pandemic environmental populations in temperate regions, such as Mediterranean coastal systems, is important if we are to evaluate the risks of infection to humans.Environmental isolates of V. cholerae (n=109 and V. parahaemolyticus (n=89 sampled at different dates, stations and water salinities were investigated for virulence genes and by a multilocus sequence-based analysis (MLSA. V. cholerae isolates were all ctxA negative and only one isolate of V. parahaemolyticus displayed trh2 gene. Most Sequence Types (ST corresponded to unique ST isolated at one date or one station. Frequent recombination events were detected among different pathogenic species, V. parahaemolyticus, V. cholerae, Vibrio mimicus and Vibrio metoecus. Recombination had a major impact on the diversification of lineages. The genetic diversity assessed by the number of ST/strain was higher in low salinity conditions for V. parahaemolyticus and V. cholerae whereas the frequency of recombination events in V. cholerae was lower in low salinity. Mediterranean coastal lagoon systems housed V. cholerae and V. parahaemolyticus with genetic diversities equivalent to the worldwide diversity described so far. The presence of STs found in human infections as well as the frequency of recombination events in environmental vibrios populations could predict a potential epidemiological risk.

  6. Historical epidemiology of the second cholera pandemic: relevance to present day disease dynamics.

    Directory of Open Access Journals (Sweden)

    Christina H Chan

    Full Text Available Despite nearly two centuries of study, the fundamental transmission dynamic properties of cholera remain incompletely characterized. We used historical time-series data on the spread of cholera in twelve European and North American cities during the second cholera pandemic, as reported in Amariah Brigham's 1832 A Treatise on Epidemic Cholera, to parameterize simple mathematical models of cholera transmission. Richards growth models were used to derive estimates of the basic reproductive number (R0 (median: 16.0, range: 1.9 to 550.9 and the proportion of unrecognized cases (mean: 96.3%, SD: 0.04%. Heterogeneity in model-generated R0 estimates was consistent with variability in cholera dynamics described by contemporary investigators and may represent differences in the nature of cholera spread. While subject to limitations associated with measurement and the absence of microbiological diagnosis, historical epidemic data are a potentially rich source for understanding pathogen dynamics in the absence of control measures, particularly when used in conjunction with simple and readily interpretable mathematical models.

  7. Spatiotemporal Variation in Environmental Vibrio cholerae in an Estuary in Southern Coastal Ecuador.

    Science.gov (United States)

    Ryan, Sadie J; Stewart-Ibarra, Anna M; Ordóñez-Enireb, Eunice; Chu, Winnie; Finkelstein, Julia L; King, Christine A; Escobar, Luis E; Lupone, Christina; Heras, Froilan; Tauzer, Erica; Waggoner, Egan; James, Tyler G; Cárdenas, Washington B; Polhemus, Mark

    2018-03-10

    Cholera emergence is strongly linked to local environmental and ecological context. The 1991-2004 pandemic emerged in Perú and spread north into Ecuador's El Oro province, making this a key site for potential re-emergence. Machala, El Oro, is a port city of 250,000 inhabitants, near the Peruvian border. Many livelihoods depend on the estuarine system, from fishing for subsistence and trade, to domestic water use. In 2014, we conducted biweekly sampling for 10 months in five estuarine locations, across a gradient of human use, and ranging from inland to ocean. We measured water-specific environmental variables implicated in cholera growth and persistence: pH, temperature, salinity, and algal concentration, and evaluated samples in five months for pathogenic and non-pathogenic Vibrio cholerae , by polymerase chain reaction (PCR). We found environmental persistence of pandemic strains O1 and O139, but no evidence for toxigenic strains. Vibrio cholerae presence was coupled to algal and salinity concentration, and sites exhibited considerable seasonal and spatial heterogeneity. This study indicates that environmental conditions in Machala are optimal for cholera re-emergence, with risk peaking during September, and higher risk near urban periphery low-income communities. This highlights a need for surveillance of this coupled cholera-estuarine system to anticipate potential future cholera outbreaks.

  8. An Ecosocial Approach to the Epidemic of Cholera in the Marshall Islands

    Directory of Open Access Journals (Sweden)

    Wesley Palmer

    2007-04-01

    Full Text Available Abstract: A cholera outbreak occurred in the Marshall Islands in December 2000 to January 2001 with over 400 cases and six deaths. Within Kwajalein Atoll, cholera occurred on Ebeye Island, while it did not occur on Kwajalein Island, three miles away. We apply Krieger’s ecosocial approach in order to explicate the reasons for this dichotomy. We first examine how Marshallese people came to embody cholera as a disease state. Secondly, we examine the (a arrangements of power, property, production, and consumption in the Ebeye-Kwajalein complex, as well as (b human biology as it has been shaped by the ecological context in order to elucidate the pathways to the embodiment of cholera. Thirdly, we examine the cumulative interplay between exposure to cholera, as well as susceptibility and resistance to the disease at the level of individuals and the island-wide level. Fourthly, we examine who is responsible for the cholera outbreak and who describes the phenomena. We conclude that the outbreak of cholera in the Marshall Islands can be considered the biologic embodiment of disparate political and economic conditions and ecological imbalance. We suggest courses of action for those interested in addressing the inequalities and working towards health.

  9. Urban cholera transmission hotspots and their implications for reactive vaccination: evidence from Bissau city, Guinea bissau.

    Directory of Open Access Journals (Sweden)

    Andrew S Azman

    Full Text Available Use of cholera vaccines in response to epidemics (reactive vaccination may provide an effective supplement to traditional control measures. In Haiti, reactive vaccination was considered but, until recently, rejected in part due to limited global supply of vaccine. Using Bissau City, Guinea-Bissau as a case study, we explore neighborhood-level transmission dynamics to understand if, with limited vaccine and likely delays, reactive vaccination can significantly change the course of a cholera epidemic.We fit a spatially explicit meta-population model of cholera transmission within Bissau City to data from 7,551 suspected cholera cases from a 2008 epidemic. We estimated the effect reactive vaccination campaigns would have had on the epidemic under different levels of vaccine coverage and campaign start dates. We compared highly focused and diffuse strategies for distributing vaccine throughout the city. We found wide variation in the efficiency of cholera transmission both within and between areas of the city. "Hotspots", where transmission was most efficient, appear to drive the epidemic. In particular one area, Bandim, was a necessary driver of the 2008 epidemic in Bissau City. If vaccine supply were limited but could have been distributed within the first 80 days of the epidemic, targeting vaccination at Bandim would have averted the most cases both within this area and throughout the city. Regardless of the distribution strategy used, timely distribution of vaccine in response to an ongoing cholera epidemic can prevent cases and save lives.Reactive vaccination can be a useful tool for controlling cholera epidemics, especially in urban areas like Bissau City. Particular neighborhoods may be responsible for driving a city's cholera epidemic; timely and targeted reactive vaccination at such neighborhoods may be the most effective way to prevent cholera cases both within that neighborhood and throughout the city.

  10. Constitutive type VI secretion system expression gives Vibrio cholerae intra- and interspecific competitive advantages.

    Directory of Open Access Journals (Sweden)

    Daniel Unterweger

    Full Text Available The type VI secretion system (T6SS mediates protein translocation across the cell membrane of Gram-negative bacteria, including Vibrio cholerae - the causative agent of cholera. All V. cholerae strains examined to date harbor gene clusters encoding a T6SS. Structural similarity and sequence homology between components of the T6SS and the T4 bacteriophage cell-puncturing device suggest that the T6SS functions as a contractile molecular syringe to inject effector molecules into prokaryotic and eukaryotic target cells. Regulation of the T6SS is critical. A subset of V. cholerae strains, including the clinical O37 serogroup strain V52, express T6SS constitutively. In contrast, pandemic strains impose tight control that can be genetically disrupted: mutations in the quorum sensing gene luxO and the newly described regulator gene tsrA lead to constitutive T6SS expression in the El Tor strain C6706. In this report, we examined environmental V. cholerae isolates from the Rio Grande with regard to T6SS regulation. Rough V. cholerae lacking O-antigen carried a nonsense mutation in the gene encoding the global T6SS regulator VasH and did not display virulent behavior towards Escherichia coli and other environmental bacteria. In contrast, smooth V. cholerae strains engaged constitutively in type VI-mediated secretion and displayed virulence towards prokaryotes (E. coli and other environmental bacteria and a eukaryote (the social amoeba Dictyostelium discoideum. Furthermore, smooth V. cholerae strains were able to outcompete each other in a T6SS-dependent manner. The work presented here suggests that constitutive T6SS expression provides V. cholerae with an advantage in intraspecific and interspecific competition.

  11. Model of cholera dissemination using geographic information systems and fuzzy clustering means: case study, Chabahar, Iran.

    Science.gov (United States)

    Pezeshki, Z; Tafazzoli-Shadpour, M; Mansourian, A; Eshrati, B; Omidi, E; Nejadqoli, I

    2012-10-01

    Cholera is spread by drinking water or eating food that is contaminated by bacteria, and is related to climate changes. Several epidemics have occurred in Iran, the most recent of which was in 2005 with 1133 cases and 12 deaths. This study investigated the incidence of cholera over a 10-year period in Chabahar district, a region with one of the highest incidence rates of cholera in Iran. Descriptive retrospective study on data of patients with Eltor and NAG cholera reported to the Iranian Centre of Disease Control between 1997 and 2006. Data on the prevalence of cholera were gathered through a surveillance system, and a spatial database was developed using geographic information systems (GIS) to describe the relation of spatial and climate variables to cholera incidences. Fuzzy clustering (fuzzy C) method and statistical analysis based on logistic regression were used to develop a model of cholera dissemination. The variables were demographic characteristics, specifications of cholera infection, climate conditions and some geographical parameters. The incidence of cholera was found to be significantly related to higher temperature and humidity, lower precipitation, shorter distance to the eastern border of Iran and local health centres, and longer distance to the district health centre. The fuzzy C means algorithm showed that clusters were geographically distributed in distinct regions. In order to plan, manage and monitor any public health programme, GIS provide ideal platforms for the convergence of disease-specific information, analysis and computation of new data for statistical analysis. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

  12. Cost-of-illness of cholera to households and health facilities in rural Malawi.

    Directory of Open Access Journals (Sweden)

    Patrick G Ilboudo

    Full Text Available Cholera remains an important public health problem in many low- and middle-income countries. Vaccination has been recommended as a possible intervention for the prevention and control of cholera. Evidence, especially data on disease burden, cost-of-illness, delivery costs and cost-effectiveness to support a wider use of vaccine is still weak. This study aims at estimating the cost-of-illness of cholera to households and health facilities in Machinga and Zomba Districts, Malawi. A cross-sectional study using retrospectively collected cost data was undertaken in this investigation. One hundred patients were purposefully selected for the assessment of the household cost-of-illness and four cholera treatment centres and one health facility were selected for the assessment conducted in health facilities. Data collected for the assessment in households included direct and indirect costs borne by cholera patients and their families while only direct costs were considered for the assessment conducted in health facilities. Whenever possible, descriptive and regression analysis were used to assess difference in mean costs between groups of patients. The average costs to patients' households and health facilities for treating an episode of cholera amounted to US$65.6 and US$59.7 in 2016 for households and health facilities, respectively equivalent to international dollars (I$ 249.9 and 227.5 the same year. Costs incurred in treating a cholera episode were proportional to duration of hospital stay. Moreover, 52% of households used coping strategies to compensate for direct and indirect costs imposed by the disease. Both households and health facilities could avert significant treatment expenditures through a broader use of pre-emptive cholera vaccination. These findings have direct policy implications regarding priority investments for the prevention and control of cholera.

  13. Cost-of-illness of cholera to households and health facilities in rural Malawi.

    Science.gov (United States)

    Ilboudo, Patrick G; Huang, Xiao Xian; Ngwira, Bagrey; Mwanyungwe, Abel; Mogasale, Vittal; Mengel, Martin A; Cavailler, Philippe; Gessner, Bradford D; Le Gargasson, Jean-Bernard

    2017-01-01

    Cholera remains an important public health problem in many low- and middle-income countries. Vaccination has been recommended as a possible intervention for the prevention and control of cholera. Evidence, especially data on disease burden, cost-of-illness, delivery costs and cost-effectiveness to support a wider use of vaccine is still weak. This study aims at estimating the cost-of-illness of cholera to households and health facilities in Machinga and Zomba Districts, Malawi. A cross-sectional study using retrospectively collected cost data was undertaken in this investigation. One hundred patients were purposefully selected for the assessment of the household cost-of-illness and four cholera treatment centres and one health facility were selected for the assessment conducted in health facilities. Data collected for the assessment in households included direct and indirect costs borne by cholera patients and their families while only direct costs were considered for the assessment conducted in health facilities. Whenever possible, descriptive and regression analysis were used to assess difference in mean costs between groups of patients. The average costs to patients' households and health facilities for treating an episode of cholera amounted to US$65.6 and US$59.7 in 2016 for households and health facilities, respectively equivalent to international dollars (I$) 249.9 and 227.5 the same year. Costs incurred in treating a cholera episode were proportional to duration of hospital stay. Moreover, 52% of households used coping strategies to compensate for direct and indirect costs imposed by the disease. Both households and health facilities could avert significant treatment expenditures through a broader use of pre-emptive cholera vaccination. These findings have direct policy implications regarding priority investments for the prevention and control of cholera.

  14. [Inactivated poliovirus vaccines: an inevitable choice for eliminating poliomyelitis].

    Science.gov (United States)

    Vidor, J D; Jean-Denis, Shu

    2016-12-06

    The inactivated poliovirus vaccine (IPV) is a very old tool in the fight against poliomyelitis. Though supplanted by oral poliovirus vaccine (OPV) in the 1960s and 1970s, the IPV has now become an inevitable choice because of the increasingly recognized risks associated with continuous use of OPVs. Following the pioneering work of Jonas Salk, who established key principles for the IPV, considerable experience has accumulated over the years. This work has led to modern Salk IPV-containing vaccines, based on the use of inactivated wildtype polioviruses, which have been deployed for routine use in many countries. Very good protection against paralysis is achieved with IPV through the presence of circulating antibodies able to neutralize virus infectivity toward motor neurons. In addition, with IPV, a variable degree of protection against mucosal infection (and therefore transmission) through mucosal antibodies and immune cells is achieved, depending on previous exposure of subjects to wildtype or vaccine polioviruses. The use of an IPV-followed-by-OPV sequential immunization schedule has the potential advantage of eliminating the vaccine-associated paralytic poliomyelitis (VAPP) risk, while limiting the risks of vaccine-derived poliovirus (VDPVs). Sabin strain-derived IPVs are new tools, only recently beginning to be deployed, and data are being generated to document their performance. IPVs will play an irreplaceable role in global eradication of polio.

  15. The Corn Smut ('Huitlacoche' as a New Platform for Oral Vaccines.

    Directory of Open Access Journals (Sweden)

    Margarita Juárez-Montiel

    Full Text Available The development of new alternative platforms for subunit vaccine production is a priority in the biomedical field. In this study, Ustilago maydis, the causal agent of common corn smut or 'huitlacoche'has been genetically engineered to assess expression and immunogenicity of the B subunit of the cholera toxin (CTB, a relevant immunomodulatory agent in vaccinology. An oligomeric CTB recombinant protein was expressed in corn smut galls at levels of up to 1.3 mg g-1 dry weight (0.8% of the total soluble protein. Mice orally immunized with 'huitlacoche'-derived CTB showed significant humoral responses that were well-correlated with protection against challenge with the cholera toxin (CT. These findings demonstrate the feasibility of using edible corn smut as a safe, effective, and low-cost platform for production and delivery of a subunit oral vaccine. The implications of this platform in the area of molecular pharming are discussed.

  16. The Corn Smut (‘Huitlacoche’) as a New Platform for Oral Vaccines

    Science.gov (United States)

    Juárez-Montiel, Margarita; Romero-Maldonado, Andrea; Monreal-Escalante, Elizabeth; Becerra-Flora, Alicia; Korban, Schuyler S.; Rosales-Mendoza, Sergio; Jiménez-Bremont, Juan Francisco

    2015-01-01

    The development of new alternative platforms for subunit vaccine production is a priority in the biomedical field. In this study, Ustilago maydis, the causal agent of common corn smut or ‘huitlacoche’has been genetically engineered to assess expression and immunogenicity of the B subunit of the cholera toxin (CTB), a relevant immunomodulatory agent in vaccinology. An oligomeric CTB recombinant protein was expressed in corn smut galls at levels of up to 1.3 mg g-1 dry weight (0.8% of the total soluble protein). Mice orally immunized with ‘huitlacoche’-derived CTB showed significant humoral responses that were well-correlated with protection against challenge with the cholera toxin (CT). These findings demonstrate the feasibility of using edible corn smut as a safe, effective, and low-cost platform for production and delivery of a subunit oral vaccine. The implications of this platform in the area of molecular pharming are discussed. PMID:26207365

  17. Comparative genome analysis of VSP-II and SNPs reveals heterogenic variation in contemporary strains of Vibrio cholerae O1 isolated from cholera patients in Kolkata, India.

    Science.gov (United States)

    Imamura, Daisuke; Morita, Masatomo; Sekizuka, Tsuyoshi; Mizuno, Tamaki; Takemura, Taichiro; Yamashiro, Tetsu; Chowdhury, Goutam; Pazhani, Gururaja P; Mukhopadhyay, Asish K; Ramamurthy, Thandavarayan; Miyoshi, Shin-Ichi; Kuroda, Makoto; Shinoda, Sumio; Ohnishi, Makoto

    2017-02-01

    Cholera is an acute diarrheal disease and a major public health problem in many developing countries in Asia, Africa, and Latin America. Since the Bay of Bengal is considered the epicenter for the seventh cholera pandemic, it is important to understand the genetic dynamism of Vibrio cholerae from Kolkata, as a representative of the Bengal region. We analyzed whole genome sequence data of V. cholerae O1 isolated from cholera patients in Kolkata, India, from 2007 to 2014 and identified the heterogeneous genomic region in these strains. In addition, we carried out a phylogenetic analysis based on the whole genome single nucleotide polymorphisms to determine the genetic lineage of strains in Kolkata. This analysis revealed the heterogeneity of the Vibrio seventh pandemic island (VSP)-II in Kolkata strains. The ctxB genotype was also heterogeneous and was highly related to VSP-II types. In addition, phylogenetic analysis revealed the shifts in predominant strains in Kolkata. Two distinct lineages, 1 and 2, were found between 2007 and 2010. However, the proportion changed markedly in 2010 and lineage 2 strains were predominant thereafter. Lineage 2 can be divided into four sublineages, I, II, III and IV. The results of this study indicate that lineages 1 and 2-I were concurrently prevalent between 2007 and 2009, and lineage 2-III observed in 2010, followed by the predominance of lineage 2-IV in 2011 and continued until 2014. Our findings demonstrate that the epidemic of cholera in Kolkata was caused by several distinct strains that have been constantly changing within the genetic lineages of V. cholerae O1 in recent years.

  18. Molecular Analyses of Vibrio cholerae O1 Clinical Strains, Including New Nontoxigenic Variants Isolated in Mexico during the Cholera Epidemic Years between 1991 and 2000▿

    Science.gov (United States)

    Lizárraga-Partida, Marcial Leonardo; Quilici, Marie-Laure

    2009-01-01

    We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI rRNA analysis revealed that these strains had ribotype profiles, denoted M5 and M6 in our study, that were identical to those previously designated Koblavi B5 or Popovic 5 and Popovic 6a or Tamayo B21a, respectively. Ribotype M5 was isolated between 1991 and 1993. This ribotype had a low level of genetic variation as detected by pulsed-field gel electrophoresis (PFGE). Ribotype M6 persisted from 1991 to 2000. However, PFGE profiles suggested that two epidemiologically unrelated strains coexisted within this single ribotype from 1995 until the end of the epidemic. We identified three new BglI ribotypes, Mx1, Mx2, and Mx3, from nontoxigenic V. cholerae O1 strains isolated between 1998 and 2000; one of them grouped strains positive for the toxin-coregulated pilus island. They differed from nontoxigenic clones isolated in Latin America and on the U.S. Gulf Coast and are probably autochthonous Mexican V. cholerae O1 variants. Most of these new variants were isolated from states surrounding the Gulf of Mexico, where the highest incidence of cholera in the country was recorded. Thus, the Mexican Gulf Coast, like the U.S. Gulf Coast, may act as an environmental reservoir of V. cholerae O1. PMID:19213700

  19. Molecular analyses of Vibrio cholerae O1 clinical strains, including new nontoxigenic variants isolated in Mexico during the Cholera epidemic years between 1991 and 2000.

    Science.gov (United States)

    Lizárraga-Partida, Marcial Leonardo; Quilici, Marie-Laure

    2009-05-01

    We studied the evolution of Vibrio cholerae O1 during the 1991 to 2000 cholera epidemic in Mexico by biochemical, serological, and molecular characterization of strains collected during this period. Strains were divided into toxigenic and nontoxigenic groups according to the presence or absence of genes encoding cholera toxin. As previously reported, we characterized two populations among toxigenic strains, which were present from the first year of the epidemic. BglI rRNA analysis revealed that these strains had ribotype profiles, denoted M5 and M6 in our study, that were identical to those previously designated Koblavi B5 or Popovic 5 and Popovic 6a or Tamayo B21a, respectively. Ribotype M5 was isolated between 1991 and 1993. This ribotype had a low level of genetic variation as detected by pulsed-field gel electrophoresis (PFGE). Ribotype M6 persisted from 1991 to 2000. However, PFGE profiles suggested that two epidemiologically unrelated strains coexisted within this single ribotype from 1995 until the end of the epidemic. We identified three new BglI ribotypes, Mx1, Mx2, and Mx3, from nontoxigenic V. cholerae O1 strains isolated between 1998 and 2000; one of them grouped strains positive for the toxin-coregulated pilus island. They differed from nontoxigenic clones isolated in Latin America and on the U.S. Gulf Coast and are probably autochthonous Mexican V. cholerae O1 variants. Most of these new variants were isolated from states surrounding the Gulf of Mexico, where the highest incidence of cholera in the country was recorded. Thus, the Mexican Gulf Coast, like the U.S. Gulf Coast, may act as an environmental reservoir of V. cholerae O1.

  20. Cholera between 1991 and 1997 in Mexico was associated with infection by classical, El Tor, and El Tor variants of Vibrio cholerae.

    Science.gov (United States)

    Alam, Munirul; Nusrin, Suraia; Islam, Atiqul; Bhuiyan, Nurul A; Rahim, Niaz; Delgado, Gabriela; Morales, Rosario; Mendez, Jose Luis; Navarro, Armando; Gil, Ana I; Watanabe, Haruo; Morita, Masatomo; Nair, G Balakrish; Cravioto, Alejandro

    2010-10-01

    Vibrio cholerae O1 biotype El Tor (ET), the cause of the current 7th pandemic, has recently been replaced in Asia and Africa by an altered ET biotype possessing cholera toxin (CTX) of the classical (CL) biotype that originally caused the first six pandemics before becoming extinct in the 1980s. Until recently, the ET prototype was the biotype circulating in Peru; a detailed understanding of the evolutionary trend of V. cholerae causing endemic cholera in Latin America is lacking. The present retrospective microbiological, molecular, and phylogenetic study of V. cholerae isolates recovered in Mexico (n = 91; 1983 to 1997) shows the existence of the pre-1991 CL biotype and the ET and CL biotypes together with the altered ET biotype in both epidemic and endemic cholera between 1991 and 1997. According to sero- and biotyping data, the altered ET, which has shown predominance in Mexico since 1991, emerged locally from ET and CL progenitors that were found coexisting until 1997. In Latin America, ET and CL variants shared a variable number of phenotypic markers, while the altered ET strains had genes encoding the CL CTX (CTX(CL)) prophage, ctxB(CL) and rstR(CL), in addition to resident rstR(ET), as the underlying regional signature. The distinct regional fingerprints for ET in Mexico and Peru and their divergence from ET in Asia and Africa, as confirmed by subclustering patterns in a pulsed-field gel electrophoresis (NotI)-based dendrogram, suggest that the Mexico epidemic in 1991 may have been a local event and not an extension of the epidemics occurring in Asia and South America. Finally, the CL biotype reservoir in Mexico is unprecedented and must have contributed to the changing epidemiology of global cholera in ways that need to be understood.

  1. Requirement for Vibrio cholerae Integration Host Factor in Conjugative DNA Transfer

    OpenAIRE

    McLeod, Sarah M.; Burrus, Vincent; Waldor, Matthew K.

    2006-01-01

    The requirement for host factors in the transmission of integrative and conjugative elements (ICEs) has not been extensively explored. Here we tested whether integration host factor (IHF) or Fis, two host-encoded nucleoid proteins, are required for transfer of SXT, a