Investigation of spatiotemporal relationship between dengue fever and drought

Science.gov (United States)

Lee, Chieh-Han; Yu, Hwa-Lung

2016-04-01

Dengue Fever is a vector-borne disease that is transmitted between human and mosquitos in tropical and sub-tropical regions. Previous studies have found significant relationship between the epidemic of dengue cases and climate variables, especially temperature and precipitation. Besides, the natural phenomena (e.g., drought) are considered that significantly drop the number of dengue cases by killing vector's breeding environment. However, in Kaohsiung City, Taiwan, there are evidences that the temporal pattern of dengue is correlated to drought events. Kaohsiung City experienced two main dengue outbreaks in 2002 and 2014 that both years were confirmed with serious drought. Especially in 2014, Kaohsiung City was suffered from extremely dengue outbreak in 2014 that reported the highest number of dengue cases in the history. Otherwise, another nearby city, Tainan City, had reported the biggest outbreak in 2015. This study constructs the spatiotemporal model of dengue incidences and index of drought events (Standardized Precipitation Index, SPI) based on the distributed lag nonlinear model (DLNM). Other meteorological measures are also included in the analysis.

Dengue fever outbreak: a clinical management experience

International Nuclear Information System (INIS)

Ahmed, S.; Illyas, M.

2008-01-01

To determine the frequency of dengue as a cause of fever and compare the clinical and haematological characteristics of Dengue-probable and Dengue-proven cases. All patients with age above 14 years, who were either hospitalized or treated in medical outdoor clinic due to acute febrile illness, were evaluated for clinical features of Dengue Fever (DF), Dengue haemorrhagic fever (DHF) and Dengue Shock Syndrome (DSS). Patients showing typical clinical features and haematological findings suggestive of Dengue fever (As per WHO criteria) were evaluated in detail for comparison of probable and confirmed cases of Dengue fever. All other cases of acute febrile illness, not showing clinical features or haematological abnormalities of Dengue fever, were excluded. The clinical and laboratory features were recorded on SPSS 11.0 programme and graded where required, for descriptive and statistical analysis. Out of 5200 patients with febrile illness, 107 (2%) presented with typical features of DF, 40/107 (37%) were Dengue-proven while 67/107 (63%) were Dengue-probable. Out of Dengue-proven cases, 38 were of DF and 2 were of DHF. Day 1 temperature ranged from 99-105 degreeC (mean 101 degree C). Chills and rigors were noticed in 86 (80%), myalgia in 67%, headache in 54%, pharyngitis in 35%, rash in 28%, and bleeding manifestations in 2% cases. Hepatomegaly in 1(0.5%), lymphadenopathy in 1 (0.5%) and splenomegaly in 12 (11.2%) cases. Leucopoenia (count 40 U/L in 57% cases. Frequency of clinically suspected dengue virus infection was 107 (2%), while confirmed dengue fever cases were 40 (0.8%) out of 5200 fever cases. Fever with chills and rigors, body aches, headache, myalgia, rash, haemorrhagic manifestations, platelet count, total leukocyte count, and ALT, are parameters to screen the cases of suspected dengue virus infection, the diagnosis cannot be confirmed unless supported by molecular studies or dengue specific IgM. (author)

[Current situation and surveillance on dengue fever in China, 2005 - 2007].

Science.gov (United States)

Wang, Qin; Xu, Zhen; Dou, Feng-Man; Zhou, Hang; Wang, Xiao-Fang; Yin, Wen-Wu; Li, Qun

2009-08-01

To provide scientific evidence for prevention and control program on dengue fever through analyzing the situation of dengue fever in China, from 2005 to 2007. Data was collected from Internet-based National Notifiable Infectious Disease Reporting System, National Enhanced Dengue Fever Surveillance System and field investigation on dengue outbreaks, described and analyzed with descriptively and by SPSS statistical software. There was a total number of 1623 dengue cases (including 1356 laboratory confirmed cases and 267 probable cases) and 1 death case reported in China from 2005 to 2007. Among the identified cases, 151 were imported from foreign countries as the Southeast Asian countries, accounting for 9.3%, while the rest 1472 cases were reported from local infections, identified only in 9 cities from Guangdong and Fujian provinces. Data from the monitoring program on Aedes Mosquitoes indicated that: The indicators of BI from 84.6% of the sentinels were over 5, and BI from 72.2% of the sentinels were over 10. This index was especially at a higher level during summer in the southern areas of China. Aedes albopictus was found in all the sentinel sites while Aedes aegypti was only found in Hainan and in limited counties of Guangdong. No dengue virus was isolated from mosquito vectors collected from national sentinel sites, whereas positive results had been detected by PCR test in Guangdong province. It was assumed that a sustainable local circulation of dengue virus had not yet been established successfully in Mainland China according to the surveillance data. However, more local outbreaks reported in Guangdong and Fujian with the wide distribution and high-level density of aedes mosquito, low antibody level in healthy population and the increasing number of imported dengue cases, there is a potential of Dengue outbreaks in southern China. An integrated mosquito vector monitoring and management system is needed in high risk area to reduce the transmission of dengue

Dengue fever outbreak: a clinical management experience.

Science.gov (United States)

Ahmed, Shahid; Ali, Nadir; Ashraf, Shahzad; Ilyas, Mohammad; Tariq, Waheed-Uz-Zaman; Chotani, Rashid A

2008-01-01

To determine the frequency of dengue as a cause of fever and compare the clinical and haematological characteristics of Dengue-probable and Dengue-proven cases. An observational study. The Combined Military Hospital, Malir Cantt., Karachi, from August 2005 to December 2006. All patients with age above 14 years, who were either hospitalized or treated in medical outdoor clinic due to acute febrile illness, were evaluated for clinical features of Dengue Fever (DF), Dengue haemorrhagic fever (DHF) and Dengue Shock Syndrome (DSS). Patients showing typical clinical features and haematological findings suggestive of Dengue fever (As per WHO criteria) were evaluated in detail for comparison of probable and confirmed cases of Dengue fever. All other cases of acute febrile illness, not showing clinical features or haematological abnormalities of Dengue fever, were excluded. The clinical and laboratory features were recorded on SPSS 11.0 programme and graded where required, for descriptive and statistical analysis. Out of 5200 patients with febrile illness, 107(2%) presented with typical features of DF, 40/107(37%) were Dengue-proven while 67/107(63%) were Dengue-probable. Out of Dengue-proven cases, 38 were of DF and 2 were of DHF. Day 1 temperature ranged from 99-1050C (mean 1010C). Chills and rigors were noticed in 86 (80%), myalgia in 67%, headache in 54%, pharyngitis in 35%, rash in 28%, and bleeding manifestations in 2% cases. Hepatomegaly in 1(0.5%), lymphadenopathy in 1(0.5%) and splenomegaly in 12 (11.2%) cases. Leucopoenia (count40 U/L in 57% cases. Frequency of clinically suspected dengue virus infection was 107 (2%), while confirmed dengue fever cases were 40 (0.8%) out of 5200 fever cases. Fever with chills and rigors, body aches, headache, myalgia, rash, haemorrhagic manifestations, platelet count, total leukocyte count, and ALT, are parameters to screen the cases of suspected dengue virus infection; the diagnosis cannot be confirmed unless supported by

Effectiveness of Mosquito Trap with Sugar Fermented Attractant to the Vector of Dengue Hemorrhagic Fever

Directory of Open Access Journals (Sweden)

Endang Puji Astuti

2011-06-01

Full Text Available Aedes aegypti is the main vector of dengue fever that is still become health problem in the world. Various control efforts has been done at several areas through chemically or naturally control. Developing mosquitoes trapping tool is an alternative method to control mosquitoes besides insecticides utilization. This laboratorium research utilize sugar fermented process to yield CO2 as one of attractan to mosquito. Production of ethanol and CO2 can be yielded from anaerob sugar fermentation proccess (without O2 by khamir Saccharomyces cerevisiae activities. The trapped mosquitoes was observed up to 48 hours exposure, the highest average of mosquito trapped is on solution treatment with yeast 1 gram (43.2% and 40 gr sugar (48.4%. The highest effectivity of trapping tool both inside or outside was on the 14th day. There were declained amount of trapped mosquitos on 16th and 18th days. This laboratorium research has described that trapping tool with sugar fermented solution were effective to control population of dengue vector.

Cost of Dengue Vector Control Activities in Malaysia.

Science.gov (United States)

Packierisamy, P Raviwharmman; Ng, Chiu-Wan; Dahlui, Maznah; Inbaraj, Jonathan; Balan, Venugopalan K; Halasa, Yara A; Shepard, Donald S

2015-11-01

Dengue fever, an arbovirus disease transmitted by Aedes mosquitoes, has recently spread rapidly, especially in the tropical countries of the Americas and Asia-Pacific regions. It is endemic in Malaysia, with an annual average of 37,937 reported dengue cases from 2007 to 2012. This study measured the overall economic impact of dengue in Malaysia, and estimated the costs of dengue prevention. In 2010, Malaysia spent US$73.5 million or 0.03% of the country's GDP on its National Dengue Vector Control Program. This spending represented US$1,591 per reported dengue case and US$2.68 per capita population. Most (92.2%) of this spending occurred in districts, primarily for fogging. A previous paper estimated the annual cost of dengue illness in the country at US$102.2 million. Thus, the inclusion of preventive activities increases the substantial estimated cost of dengue to US$175.7 million, or 72% above illness costs alone. If innovative technologies for dengue vector control prove efficacious, and a dengue vaccine was introduced, substantial existing spending could be rechanneled to fund them. © The American Society of Tropical Medicine and Hygiene.

Climate change and the emergence of vector-borne diseases in Europe: case study of dengue fever.

Science.gov (United States)

Bouzid, Maha; Colón-González, Felipe J; Lung, Tobias; Lake, Iain R; Hunter, Paul R

2014-08-22

Dengue fever is the most prevalent mosquito-borne viral disease worldwide. Dengue transmission is critically dependent on climatic factors and there is much concern as to whether climate change would spread the disease to areas currently unaffected. The occurrence of autochthonous infections in Croatia and France in 2010 has raised concerns about a potential re-emergence of dengue in Europe. The objective of this study is to estimate dengue risk in Europe under climate change scenarios. We used a Generalized Additive Model (GAM) to estimate dengue fever risk as a function of climatic variables (maximum temperature, minimum temperature, precipitation, humidity) and socioeconomic factors (population density, urbanisation, GDP per capita and population size), under contemporary conditions (1985-2007) in Mexico. We then used our model estimates to project dengue incidence under baseline conditions (1961-1990) and three climate change scenarios: short-term 2011-2040, medium-term 2041-2070 and long-term 2071-2100 across Europe. The model was used to calculate average number of yearly dengue cases at a spatial resolution of 10 × 10 km grid covering all land surface of the currently 27 EU member states. To our knowledge, this is the first attempt to model dengue fever risk in Europe in terms of disease occurrence rather than mosquito presence. The results were presented using Geographical Information System (GIS) and allowed identification of areas at high risk. Dengue fever hot spots were clustered around the coastal areas of the Mediterranean and Adriatic seas and the Po Valley in northern Italy. This risk assessment study is likely to be a valuable tool assisting effective and targeted adaptation responses to reduce the likely increased burden of dengue fever in a warmer world.

Dengue fever and dengue haemorrhagic fever in adolescents and adults.

Science.gov (United States)

Tantawichien, Terapong

2012-05-01

Dengue fever (DF) is endemic in tropical and subtropical zones and the prevalence is increasing across South-east Asia, Africa, the Western Pacific and the Americas. In recent years, the spread of unplanned urbanisation, with associated substandard housing, overcrowding and deterioration in water, sewage and waste management systems, has created ideal conditions for increased transmission of the dengue virus in tropical urban centres. While dengue infection has traditionally been considered a paediatric disease, the age distribution of dengue has been rising and more cases have been observed in adolescents and adults. Furthermore, the development of tourism in the tropics has led to an increase in the number of tourists who become infected, most of whom are adults. Symptoms and risk factors for dengue haemorrhagic fever (DHF) and severe dengue differ between children and adults, with co-morbidities and incidence in more elderly patients associated with greater risk of mortality. Treatment options for DF and DHF in adults, as for children, centre round fluid replacement (either orally or intravenously, depending on severity) and antipyretics. Further data are needed on the optimal treatment of adult patients.

A survey of bacterial, fungal and plant metabolites against Aedes aegypti (Diptera: Culicidae), the vector of yellow and dengue fevers and Zika virus

Science.gov (United States)

Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. Some bacterial, fungal and plant metabolites including Amaryllidaceae alkaloids belonging to different chemical subgroups, including anthracenes, azoxymethoxytetrahydropy...

Dengue fever and dengue haemorrhagic fever in adolescents and adults

OpenAIRE

Tantawichien, Terapong

2012-01-01

Dengue fever (DF) is endemic in tropical and subtropical zones and the prevalence is increasing across South-east Asia, Africa, the Western Pacific and the Americas. In recent years, the spread of unplanned urbanisation, with associated substandard housing, overcrowding and deterioration in water, sewage and waste management systems, has created ideal conditions for increased transmission of the dengue virus in tropical urban centres. While dengue infection has traditionally been considered a...

Treatment of dengue fever

Directory of Open Access Journals (Sweden)

Rajapakse S

2012-07-01

Full Text Available Senaka Rajapakse,1,2 Chaturaka Rodrigo,1 Anoja Rajapakse31Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Sri Lanka; 2Lincoln County Hospital, United Lincolnshire NHS Trust, Lincoln, UK; 3Kings Mill Hospital, Sherwood Forest NHS Foundation Trust, Mansfield, UKAbstract: The endemic area for dengue fever extends over 60 countries, and approximately 2.5 billion people are at risk of infection. The incidence of dengue has multiplied many times over the last five decades at an alarming rate. In the endemic areas, waves of infection occur in epidemics, with thousands of individuals affected, creating a huge burden on the limited resources of a country's health care system. While the illness passes off as a simple febrile episode in many, a few have a severe illness marked by hypovolemic shock and bleeding. Iatrogenic fluid overload in the management may further complicate the picture. In this severe form dengue can be fatal. Tackling the burden of dengue is impeded by several issues, including a lack of understanding about the exact pathophysiology of the infection, inability to successfully control the vector population, lack of specific therapy against the virus, and the technical difficulties in developing a vaccine. This review provides an overview on the epidemiology, natural history, management strategies, and future directions for research on dengue, including the potential for development of a vaccine.Keywords: dengue, treatment, fluid resuscitation

Dengue encephalitis–A rare manifestation of dengue fever

OpenAIRE

Madi, Deepak; Achappa, Basavaprabhu; Ramapuram, John T; Chowta, Nityananda; Laxman, Mridula; Mahalingam, Soundarya

2014-01-01

The clinical spectrum of dengue fever ranges from asymptomatic infection to dengue shock syndrome. Dengue is classically considered a non-neurotropic virus. Neurological complications are not commonly seen in dengue. The neurological manifestations seen in dengue are encephalitis, meningitis, encephalopathy, stroke and Guillain-Barré syndrome. Dengue encephalitis is a rare disease. We report an interesting case of dengue encephalitis from Southern India. A 49-year-old gentleman presented with...

CLINICAL AND LABORATORY PROFILE OF DENGUE FEVER

Directory of Open Access Journals (Sweden)

Farhan Fazal

2015-02-01

Full Text Available AIM: Dengue is a major health problem in many parts of India and Gulbarga (North Karnataka was previously not a known endemic area f or dengue. Infection with dengue virus can cause a spectrum of three clinical syndromes , classic dengue fever (DF , dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. The present study was undertaken to determine the disease profile of dengue virus infection in hospitalized patients. METHODS AND MATERIAL: One hundred patients admitted in Basaveshwar Teaching and General hospital with fever more than 38.5 degree Celsius and IgM dengue positive were selected. They were followed from the onset of fever to twelve days or till they are recovered according to WHO discharge criteria whichever is earlier. They underwent relevant investigations to identify specific organ dysfunction and categorize them into the spectrum of Dengue fever in accordance to W HO criteria . RESULTS: Out of 100 cases in this study 70 cases belongs to DF , 23 cases to DHF and 7 cases to DSS based on WHO criteria. All the cases had fever (100%. Other common symptoms noted were myalgia (61% , joint pain (54% , headache (66% , vomitin g (55% , pain abdomen (48% , rash (41% , hepatomegaly (20% , bleeding (21% and shock (8%. Hess test was positive in 24% patients. Low platelet count of less than 100 , 000/cu mm according to WHO criteria was present in 73% patients. Deranged liver functio n test and renal parameters were seen in 26 and 8 patients respectively . Mortality documented was 7 patients due to delayed presentation. The average duration of hospital stay was 4.65 days. CONCLUSION: Dengue fever was a more common manifestation than DHF or DSS. During aepidemic , dengue should be strongly considered on the differential diagnosis of any patient with fever. The treatment of dengue is mainly fluid management and supportive. Early recognition and management of alarm symptoms is the key to bet ter outcome

Appendicular perforation in dengue fever: our experience

Directory of Open Access Journals (Sweden)

Gunjan Desai

2014-09-01

Full Text Available Dengue viral infections have become one of major emerging infectious diseases in the tropics. Acute abdomen occurring in dengue viral infection is not uncommon. The spectrums of acute surgical emergencies which raise suspicion of an abdominal catastrophe in patients presenting with dengue fever include acute pancreatitis, acute acalculous cholecystitis, non-specific peritonitis and very rarely acute appendicitis. The presence of low white cell count and platelet count can raise suspicion of a diagnosis of dengue in a patient presenting with acute abdominal pain, during a dengue epidemic. We herein report three patients with dengue fever who had appendicular perforation during the course of their viral fever.

Dengue fever: diagnosis and treatment.

Science.gov (United States)

Wiwanitkit, Viroj

2010-07-01

Dengue fever is a common tropical infection. This acute febrile illness can be a deadly infection in cases of severe manifestation, causing dengue hemorrhagic shock. In this brief article, I will summarize and discuss the diagnosis and treatment of this disease. For diagnosis of dengue, most tropical doctors make use of presumptive diagnosis; however, the definite diagnosis should be based on immunodiagnosis or viral study. Focusing on treatment, symptomatic and supportive treatment is the main therapeutic approach. The role of antiviral drugs in the treatment of dengue fever has been limited, but is currently widely studied.

Dengue and the risk of urban yellow fever reintroduction in São Paulo State, Brazil

Directory of Open Access Journals (Sweden)

Massad Eduardo

2003-01-01

Full Text Available OBJECTIVE: To propose a mathematical method for the estimation of the Basic Reproduction Number, R0, of urban yellow fever in a dengue-infested area. METHODS: The method is based on the assumption that, as the same vector (Aedes aegypti causes both infections, all the quantities related to the mosquito, estimated from the initial phase of dengue epidemic, could be applied to yellow fever dynamics. It is demonstrated that R0 for yellow fever is, on average, 43% lower than that for dengue. This difference is due to the longer dengue viremia and its shorter extrinsic incubation period. RESULTS: In this study the analysis was expanded to the epidemiological situation of dengue in São Paulo in the year 2001. The total number of dengue cases increased from 3,582 in 2000 to 51,348 in 2001. It was then calculated R0 for yellow fever for every city which have shown R0 of dengue greater than 1. It was also estimated the total number of unprotected people living in highly risky areas for urban yellow fever. CONCLUSIONS: Currently there is a great number of non-vaccinated people living in Aedes aegypti infested area in the state of São Paulo.

[Epidemiologic surveillance of dengue fever in the French army from 1996 to 1999].

Science.gov (United States)

Meynard, J B; Ollivier-Gay, L; Deparis, X; Durand, J P; Michel, R; Pages, F; Matton, T; Boutin, J P; Tolou, H; Merouze, F; Baudon, D

2001-01-01

Dengue fever is a widespread disease that can occur outside tropical areas. Several thousand French military personnel are exposed to this infectious risk each year and exposure is expected to rise with the creation of a professional army and the increasing number of foreign missions. As a result, dengue fever has become a major priority for the Armed Services Health Corps (ASHC). A system of epidemiological surveillance based on the active participation of all military physicians has been designed by the ASHC to collect and analyze all data relevant to cases of dengue fever involving French military personnel stationed overseas or at home. The purpose of this study is to present data compiled for the period from 1996 to 1999. Analysis of these data demonstrated that the incidence of dengue fever peaked in 1997 due to epidemic outbreaks occurring in French Polynesia and Martinique. In response to these outbreaks control measures were adapted especially in regard to vector control. This study shows that the system of surveillance implemented by the ASHC is an effective but still perfectible tool.

Facing dengue fever - our first experience

Directory of Open Access Journals (Sweden)

Cvjetković Dejan

2017-01-01

Full Text Available Introduction. Dengue fever is a mosquito-borne disease caused by dengue virus, endemic in tropical and subtropical regions, where it is mostly imported from. The most common clinical form is classic dengue fever. We presented the first dengue case microbiologically confirmed in Serbia. Case report. A 34-year-old male got classic dengue fever after arrival from Cuba. The disease occurred suddenly with fever, myalgias, skin rash, hepatosplenomegaly, cytopenia, abnormal aminotransferase and creatine kinase levels. The diagnosis was confirmed with virological diagnostic methods. Significant leukopenia and thrombocytopenia as well as elevation of serum creatine kinase activity were recorded from the very beginning of hospitalization, but were gradually normalized. The whole duration of hospitalization was accompanied by laboratory signs of liver lesion. The disease had favourable outcome. At hospital discharge, the patient was afebrile, asymptomatic, with discrete erythematous rash on torso and arms, normal hemathological values and creatine kinase level and moderately elevated alanine-aminotransferase level. Conclusion. Considering global climate changes and growing international traffic, our health care service needs to be ready for possible massive outbreaks of dengue and other tropical infectious diseases in forthcoming years.

Socio-economic and Climate Factors Associated with Dengue Fever Spatial Heterogeneity: A Worked Example in New Caledonia

Science.gov (United States)

Teurlai, Magali; Menkès, Christophe Eugène; Cavarero, Virgil; Degallier, Nicolas; Descloux, Elodie; Grangeon, Jean-Paul; Guillaumot, Laurent; Libourel, Thérèse; Lucio, Paulo Sergio; Mathieu-Daudé, Françoise; Mangeas, Morgan

2015-01-01

Background/Objectives Understanding the factors underlying the spatio-temporal distribution of infectious diseases provides useful information regarding their prevention and control. Dengue fever spatio-temporal patterns result from complex interactions between the virus, the host, and the vector. These interactions can be influenced by environmental conditions. Our objectives were to analyse dengue fever spatial distribution over New Caledonia during epidemic years, to identify some of the main underlying factors, and to predict the spatial evolution of dengue fever under changing climatic conditions, at the 2100 horizon. Methods We used principal component analysis and support vector machines to analyse and model the influence of climate and socio-economic variables on the mean spatial distribution of 24,272 dengue cases reported from 1995 to 2012 in thirty-three communes of New Caledonia. We then modelled and estimated the future evolution of dengue incidence rates using a regional downscaling of future climate projections. Results The spatial distribution of dengue fever cases is highly heterogeneous. The variables most associated with this observed heterogeneity are the mean temperature, the mean number of people per premise, and the mean percentage of unemployed people, a variable highly correlated with people's way of life. Rainfall does not seem to play an important role in the spatial distribution of dengue cases during epidemics. By the end of the 21st century, if temperature increases by approximately 3°C, mean incidence rates during epidemics could double. Conclusion In New Caledonia, a subtropical insular environment, both temperature and socio-economic conditions are influencing the spatial spread of dengue fever. Extension of this study to other countries worldwide should improve the knowledge about climate influence on dengue burden and about the complex interplay between different factors. This study presents a methodology that can be used as a

Hemophagocytic syndrome in classic dengue fever

Directory of Open Access Journals (Sweden)

Sayantan Ray

2011-01-01

Full Text Available A 24-year-old previously healthy girl presented with persistent fever, headache, and jaundice. Rapid-test anti-dengue virus IgM antibody was positive but anti-dengue IgG was nonreactive, which is suggestive of primary dengue infection. There was clinical deterioration during empiric antibiotic and symptomatic therapy. Bone marrow examination demonstrated the presence of hemophagocytosis. Diagnosis of dengue fever with virus-associated hemophagocytic syndrome was made according to the diagnostic criteria of the HLH 2004 protocol of the Histiocyte Society. The patient recovered with corticosteroid therapy. A review of literature revealed only a handful of case reports that showed the evidence that this syndrome is caused by dengue virus. Our patient is an interesting case of hemophagocytic syndrome associated with classic dengue fever and contributes an additional case to the existing literature on this topic. This case highlights the need for increased awareness even in infections not typically associated with hemophagocytic syndrome.

Dengue fever with rectus sheath hematoma: A case report

Directory of Open Access Journals (Sweden)

Anurag Sharma

2014-01-01

Full Text Available Dengue fever, also known as breakbone fever, is an infectious tropical disease caused by the Dengue virus. It is associated with a number of complications, which are well documented. However, Dengue fever associated with rectus sheath hematoma (RSH is a very rare complication. Only one case report has been published prior supporting the association of Dengue fever with RSH. We report a case of Dengue fever who presented with RSH and was successfully treated conservatively. RSH is also an uncommon cause of acute abdominal pain. It is accumulation of blood in the sheath of the rectus abdominis, secondary to rupture of an epigastric vessel or muscle tear.

Impact of Climate on the incidence of Dengue Haemorrhagic fever in Semarang City

Science.gov (United States)

Khairunisa, Ummi; Endah Wahyuningsih, Nur; Suhartono; Hapsari

2018-05-01

Dengue Haemorrhagic Fever (DHF) is one of major health problems in Indonesia. DHF is a caused by the dengue virus and potentially deadly infection spread by some mosquitos. The mosquito Aedes aegypti is the main species that spreads this disease. The incidence rate of dengue haemorrhagic fever was still increased in 2011 to 2015 in Indonesia. Dengue viruses and their mosquito vectors are sensitive to their environment. Temperature, rainfall and humidity have well-define roles in the transmission cycle. Therefore changes in these conditions may contribute to increasing incidence. The aim of this study was to analyze the relationship between climate factors and the incidence rate of dengue hemorrhagic fever in Semarang City. The type of research was analytic with cross sectional study. The sample used is the climate data from Meteorology, Climatology and Geophysics Agency (BMKG) and the number of dengue cases from Health Office in Semarang City from 2011 to 2016. Data were analyzed using Pearson trials with α=0,05. Base on this study here air temperature and relative humidity were moderate correlation with negative direction on air temperature (p = 0,000 and r = -0, 429), weakly correlation with positive direction on rainfall (p = 0,014 and r = 0,288) and humidity (p=0,001 and r = 0,382) with dengue hemorrhagic fever incidence in Semarang City. The conclusions of this study there were correlation between climate (air temperature, rainfall, and relative humidity) and DHF in Semarang City in 2011-2016.

Environmental and Socio-Demographic Determinants of Dengue Fever in Colombo City, Sri Lanka

Science.gov (United States)

Tipre, Meghan; Luvall, Jeffrey; Haque, Akhlaque; McClure, Leslie; Zaitchik, Ben; Sathiakumar, Nalini

2014-01-01

Dengue fever has increased exponentially in Sri Lanka, from 24.4 cases per 100,000 in 2003 to 165.3 per 100,000 population in 2013. Although early warning systems using predictor models have been previously developed in other settings, it is important to develop such models in each local setting. Further, the ability of these models to be applicable at smaller geographic units will enhance current vector control and disease surveillance measures. The aim of this paper was to identify environmental and socio-economic status (SES) risk factors that may predict dengue fever at the Gram Niladhari Divisions (GND) level (smallest administrative unit) in Colombo city, Sri Lanka. These factors included landcover classes, amount of vegetation, population density, water access and neighborhood SES as determined by roof type. A geographically weighted regression (GWR) was used to develop the prediction model. A total 55 GND units covering an area of 37 sq km were investigated. We found that GND units with decreased vegetation, higher built-up area, higher population density and poor access to tap-water supply were associated with high risk of dengue; the pertinent GND units were concentrated in the center of the city. This is the first study in Sri Lanka to include both environmental and socio-demographic factors in prediction models for dengue fever. The methodology may be useful in enhancing ongoing dengue fever control measures in the country, and to be extended to other countries in the region that have an increasing incidence of dengue fever.

Ecology and control of dengue vector mosquitoes in Taiwan.

Science.gov (United States)

Chen, Y R; Hwang, J S; Guo, Y J

1994-12-01

Due to rapid urbanization, industrialization and social changes in recent years, the use of packing materials and tires has dramatically increased in the Taiwan area. What is more is that some parts of southern Taiwan are short of water resources and water preservation with huge containers becomes part of custom in those areas. Storage water containers, waste vessels and tires are good habitats for Aedes. Meanwhile, some persons traveling to dengue endemic countries bring the dengue disease back to Taiwan. Surveys taken since 1988 show that dengue occurs mainly in the urban and coastal areas where Aedes aegypti is prevalent. This species is the most important, if not the only, vector of dengue in Taiwan. It appears that the types of Aedes breeding have changed quickly. In dengue fever epidemic areas, the most popular breeding sites are ornamental containers (38.8%), storage water containers (30.1%), discarded containers (25.4%), receptacles (3.3%) and water collection in the basement (2.2%). In dengue fever epidemic areas, those building basements, huge water containers, waste vessels and waste tires in open fields are most difficult to clean up and manage and become the most popular Aedes habitats. We established a waste recycling system and promoted a breeding site reduction campaign for waste management, including the application of Temephos in containers to kill larvae. For the drinking water management, fish were released in water containers to prevent larval breeding. It should be mentioned that with the integrated pest control and regular inspections of Aedes larvae in Taiwan the density figures 1, 2-5, and 6 or above for Aedes aegypti were 38.7%, 42.9%, and 18.4%, respectively, in 1988, and in 1993 were 90.8%, 9.2% and 0%. The incidence of dengue fever cases has 98% decreased since 1988. In 1990 and 1993, there was no indigenous cases. We have concluded that integrated pest control is the best and most effective method for dengue fever control, including

FEVER AS INDICATOR TO SECONDARY INFECTION IN DENGUE VIRAL INFECTION

Directory of Open Access Journals (Sweden)

Soegeng Soegijanto

2018-04-01

Full Text Available Dengue Virus Infections are distributed in tropical and sub-tropical regions and transmitted by the mosquitoes such as Aedes aegypti and Aedes albopictus. Dengue virus can cause dengue fever, dengue hemorrhagic fever and dengue shock syndrome or dengue and severe dengue classified by World Health Organization. Beside it concurrent infection virus salmonella had been found some cases who showed fever more than 7 days. Concurrent infection with two agents can result in an illness having overlapping symptoms creating a diagnostic dilemma for treating physician, such as dengue fever with typhoid fever. The aim of this research is detection of dengue virus and secondary infection with Salmonella typhi in patients suspected dengue virus infection. Detection of dengue virus and Salmonella typhi using immunochromatography test such as NS1, IgG/IgM for dengue virus infection, and IgM/IgG Salmonella and blood culture. The fifty children with dengue virus infection came to Soerya hospital and 17 cases suspected dengue virus infection, five cases showed a positive NS1 on the second day of fever and one case concurrent with clinical manifestation of convulsi on the third days of fever there were five cases only showed positive. It was showed in this study that on the fourth to six day of fever in dengue virus infection accompanied by antibody IgM & IgG dengue. There were 12 cases showed the clinical manifestation of concurrent dengue viral infection and Salmonella, all of them showed a mild clinical manifestation and did not show plasma leakage and shock. In this study we found the length of stay of concurrent Dengue Virus Infection and Salmonella infection is more than 10 days. These patients were also more likely to have co-existing haemodynamic disturbances and bacterial septicaemia which would have required treatment with inotropes and antibiotics. This idea is very important to make update dengue viral management to decrease mortality in outbreak try to

Dengue hemorrhagic fever and acute hepatitis: a case report

Directory of Open Access Journals (Sweden)

Maria Paula Gomes Mourão

Full Text Available Dengue fever is the world's most important viral hemorrhagic fever disease, the most geographically wide-spread of the arthropod-born viruses, and it causes a wide clinical spectrum of disease. We report a case of dengue hemorrhagic fever complicated by acute hepatitis. The initial picture of classical dengue fever was followed by painful liver enlargement, vomiting, hematemesis, epistaxis and diarrhea. Severe liver injury was detected by laboratory investigation, according to a syndromic surveillance protocol, expressed in a self-limiting pattern and the patient had a complete recovery. The serological tests for hepatitis and yellow fever viruses were negative. MAC-ELISA for dengue was positive.

Dengue hemorrhagic fever and acute hepatitis: a case report.

Science.gov (United States)

Mourão, Maria Paula Gomes; Lacerda, Marcus Vinícius Guimarães de; Bastos, Michele de Souza; Albuquerque, Bernardino Cláudio de; Alecrim, Wilson Duarte

2004-12-01

Dengue fever is the world's most important viral hemorrhagic fever disease, the most geographically wide-spread of the arthropod-born viruses, and it causes a wide clinical spectrum of disease. We report a case of dengue hemorrhagic fever complicated by acute hepatitis. The initial picture of classical dengue fever was followed by painful liver enlargement, vomiting, hematemesis, epistaxis and diarrhea. Severe liver injury was detected by laboratory investigation, according to a syndromic surveillance protocol, expressed in a self-limiting pattern and the patient had a complete recovery. The serological tests for hepatitis and yellow fever viruses were negative. MAC-ELISA for dengue was positive.

Vitamin D serostatus and dengue fever progression to dengue hemorrhagic fever/dengue shock syndrome.

Science.gov (United States)

Villamor, E; Villar, L A; Lozano, A; Herrera, V M; Herrán, O F

2017-10-01

Vitamin D could modulate pathways leading to dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS). We examined the associations of serum total 25-hydroxy vitamin D [25(OH)D] and vitamin D binding protein (VDBP) concentrations in patients with uncomplicated dengue fever (DF) with risk of progression to DHF/DSS. In a case-control study nested in a cohort of DF patients who were followed during the acute episode in Bucaramanga, Colombia, we compared 25(OH)D and VDBP at onset of fever between 110 cases who progressed to DHF/DSS and 235 DF controls who did not progress. 25(OH)D concentrations were also compared between the acute sample and a sample collected >1 year post-convalescence in a subgroup. Compared with 25(OH)D ⩾75 nmol/l, adjusted odds ratios (95% CI) for progression were 0·44 (0·22-0·88) and 0·13 (0·02-1·05) for 50 to 75 nmol/l (vitamin D insufficiency) and <50 nmol/l (vitamin D deficiency), respectively (P, trend = 0·003). Mean 25(OH)D concentrations were much lower post-convalescence compared with the acute episode, regardless of case status. Compared with controls, mean VDBP was non-significantly lower in cases. We conclude that low serum 25(OH)D concentrations in DF patients predict decreased odds of progression to DHF/DSS.

The Significance of Prolonged and Saddleback Fever in Hospitalised Adult Dengue.

Directory of Open Access Journals (Sweden)

Deborah Hl Ng

Full Text Available Dengue fever is gaining importance in Singapore with an increase in the number of cases and mortality in recent years. Although prolonged and saddleback fever have been reported in dengue fever, there are no specific studies on their significance in dengue. This study aims to examine the prevalence of prolonged and saddleback fever in dengue as well as their associations with dengue severity. A total of 2843 polymerase-chain reaction (PCR confirmed dengue patients admitted to Tan Tock Seng Hospital from 2004 to 2008 were included in the study. Sixty-nine percent of them were male with a median age of 34 years. Prolonged fever (fever > 7 days duration was present in 572 (20.1% of patients. Dengue hemorrhagic fever (DHF, dengue shock syndrome (DSS and severe dengue (SD were significantly more likely to occur in patients with prolonged fever. Mucosal bleeding, anorexia, diarrhea, abdominal pain, nausea or vomiting, lethargy, rash, clinical fluid accumulation, hepatomegaly, nosocomial infection, leukopenia, higher neutrophil count, higher hematocrit, higher alanine transaminase (ALT and aspartate transaminase (AST, higher creatinine, lower protein and prolonged activated partial thromboplastin time (APTT were significantly associated with prolonged fever but not platelet count or prothrombin time (PT. Saddleback fever was present in 165 (5.8%. Although DHF and SD were more likely to occur in patients in those with saddleback fever, DSS was not. Compared with prolonged fever, saddleback fever did not show many significant associations except for diarrhea, abdominal pain, clinical fluid accumulation, hematocrit and platelet change, and lower systolic blood pressure. This study demonstrates that prolonged fever may be associated with various warning signs and more severe forms of dengue (SD, DSS, DHF, while saddleback fever showed associations with DHF and SD but not DSS. The presence of prolonged or saddleback fever in dengue patients should therefore

Stability Analysis Susceptible, Exposed, Infected, Recovered (SEIR) Model for Spread Model for Spread of Dengue Fever in Medan

Science.gov (United States)

Side, Syafruddin; Molliq Rangkuti, Yulita; Gerhana Pane, Dian; Setia Sinaga, Marlina

2018-01-01

Dengue fever is endemic disease which spread through vector, Aedes Aegypty. This disease is found more than 100 countries, such as, United State, Africa as well Asia, especially in country that have tropic climate. Mathematical modeling in this paper, discusses the speed of the spread of dengue fever. The model adopting divided over four classes, such as Susceptible (S), Exposed (E), Infected (I) and Recovered (R). SEIR model further analyzed to detect the re-breeding value based on the number reported case by dengue in Medan city. Analysis of the stability of the system in this study is asymptotically stable indicating a case of endemic and unstable that show cases the endemic cases. Simulation on the mathematical model of SEIR showed that require a very long time to produce infected humans will be free of dengue virus infection. This happens because of dengue virus infection that occurs continuously between human and vector populations.

The correlation between temperature and humidity with the population density of Aedes aegypti as dengue fever’s vector

Science.gov (United States)

Sintorini, M. M.

2018-01-01

The weather change in South East Asia have triggered the increase of dengue fever illness in Indonesia. Jakarta has been declared as one of dengue fever endemic region. This research aim to gain the dynamic of dengue fever incidents related to temperature, humidity and the population density of Aedes aegypti. This research implementated Design of Ecology Study. The samples were collected from April 2015 to March 2016, from houses located in the suburbs i.e. Pasar Minggu, Ciracas, Sunter Agung, Palmerah and Bendungan Hilir. The sampling based on Sampling Design Cluster and each suburb represents 153 samples. The research shows correlation between temperature (p value 0.000) and humidity (p value 0,000) with Aedes aegypti as dengue fever’s Vector. Therefore, an early warning system should be developed based on environmental factors to anticipate the spread of dengue fever.

A spatiotemporal dengue fever early warning model accounting for nonlinear associations with meteorological factors: a Bayesian maximum entropy approach

Science.gov (United States)

Lee, Chieh-Han; Yu, Hwa-Lung; Chien, Lung-Chang

2014-05-01

Dengue fever has been identified as one of the most widespread vector-borne diseases in tropical and sub-tropical. In the last decade, dengue is an emerging infectious disease epidemic in Taiwan especially in the southern area where have annually high incidences. For the purpose of disease prevention and control, an early warning system is urgently needed. Previous studies have showed significant relationships between climate variables, in particular, rainfall and temperature, and the temporal epidemic patterns of dengue cases. However, the transmission of the dengue fever is a complex interactive process that mostly understated the composite space-time effects of dengue fever. This study proposes developing a one-week ahead warning system of dengue fever epidemics in the southern Taiwan that considered nonlinear associations between weekly dengue cases and meteorological factors across space and time. The early warning system based on an integration of distributed lag nonlinear model (DLNM) and stochastic Bayesian Maximum Entropy (BME) analysis. The study identified the most significant meteorological measures including weekly minimum temperature and maximum 24-hour rainfall with continuous 15-week lagged time to dengue cases variation under condition of uncertainty. Subsequently, the combination of nonlinear lagged effects of climate variables and space-time dependence function is implemented via a Bayesian framework to predict dengue fever occurrences in the southern Taiwan during 2012. The result shows the early warning system is useful for providing potential outbreak spatio-temporal prediction of dengue fever distribution. In conclusion, the proposed approach can provide a practical disease control tool for environmental regulators seeking more effective strategies for dengue fever prevention.

A survey of bacterial, fungal and plant metabolites against Aedes aegypti (Diptera: Culicidae), the vector of yellow and dengue fevers and Zika virus

OpenAIRE

Masi Marco; Cimmino Alessio; Tabanca Nurhayat; Becnel James J.; Bloomquist Jeffrey R.; Evidente Antonio

2017-01-01

Aedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. Some bacterial, fungal and plant metabolites belonging to different chemical subgroups, including Amaryllidaceae alkaloids, anthracenes, azoxymethoxytetrahydropyrans, cytochalasans, 2,5-diketopiperazines, isochromanones, naphthoquinones, organic small acids and their methyl esters, sterols and terpenes including sesquiterpenes and diterpenes, were tested for their ...

Dengue vector control: present status and future prospects.

Science.gov (United States)

Yap, H H; Chong, N L; Foo, A E; Lee, C Y

1994-12-01

Dengue Fever (DF) and Dengue Haemorrhagic Fever (DHF) have been the most common urban diseases in Southeast Asia since the 1950s. More recently, the diseases have spread to Central and South America and are now considered as worldwide diseases. Both Aedes aegypti and Aedes albopictus are involved in the transmission of DF/DHF in Southeast Asian region. The paper discusses the present status and future prospects of Aedes control with reference to the Malaysian experience. Vector control approaches which include source reduction and environmental management, larviciding with the use of chemicals (synthetic insecticides and insect growth regulators and microbial insecticide), and adulticiding which include personal protection measures (household insecticide products and repellents) for long-term control and space spray (both thermal fogging and ultra low volume sprays) as short-term epidemic measures are discussed. The potential incorporation of IGRs and Bacillus thuringiensis-14 (Bti) as larvicides in addition to insecticides (temephos) is discussed. The advantages of using water-based spray over the oil-based (diesel) spray and the use of spray formulation which provide both larvicidal and adulticidal effects that would consequently have greater impact on the overall vector and disease control in DF/DHF are highlighted.

The effect of vector control strategy against Dengue transmission between mosquitoes and humans

Directory of Open Access Journals (Sweden)

Chen-Xia Yang

2017-03-01

Full Text Available With the consideration of mechanism of prevention and control for the spread of dengue fever, a mathematical model of dengue fever dynamical transmission between mosquitoes and humans, incorporating a vector control strategy of impulsive culling of mosquitoes, is proposed in this paper. By using the comparison principle, Floquet theorem and some of analytical methods, we obtain the basic reproductive number $\\mathcal{R}_0$ for this infectious disease, which illustrates the stability of the disease-free periodic solution and the uniform persistence of the disease. Further, the explicit conditions determining the backward or forward bifurcation are obtained and the culling rate $\\phi$ is a major effect on the occurrence of backward bifurcation. Finally, numerical simulations are given to verify the correctness of theoretical results and the most efficiency of vector control strategy.

Dengue fever/dengue haemorrhagic fever in Filipino children: clinical experience during the 1983-1984 epidemic.

Science.gov (United States)

Songco, R S; Hayes, C G; Leus, C D; Manaloto, C O

1987-09-01

A total of 377 Filipino children out of a total of 5,427 admissions from October 31, 1983 to March 31, 1984 were found to have dengue fever/dengue haemorrhagic fever The present clinical presentation of these infections was basically similar to that in previous epidemics but hepatomegaly and pleural effusion were less frequent and cardiac involvement, more frequent. The discrepancies between the clinical syndromes and HI antibody responses were evident; thus, the values used for the interpretation of the antibody titers must be reassessed.

Potential Analysis of Promoting the Dengue Hemorrhagic Fever Prevention Through Youtube

Directory of Open Access Journals (Sweden)

Mara Ipa

2014-11-01

Full Text Available Background: Deal with health promotion efforts in terms of disease control using media or social networking is an innovative breakthrough in a region having a broad range of territory, such as Indonesia and others countries alike. The use of social media /video platforms such as youtube, vimeo, veoh in health promotion has been significantly increased. This study aims to determine the potential availability of information about dengue hemorrhagic fever (DHF on YouTube social media and social media potential of as a medium for dissemination of knowledge of health promotion. Methods: This study used a social media site or website which is the most popular video hosting sites in the world, ‘YouTube’, with the keyword of ‘dengue hemorrhagic fever’. The selected video directly associated with DHF, videos in English that were included in this study using Latin letters in the description of the video; with duration less than or equal to 5 minutes. 76 videos analyzed with content analysis methods. Results:Showed that 76 videos divided into categories of prevention, control, transmission, treatment, dengue fever treatment, and other categories. Other information classification categories explain the severity of dengue virus infection, dengue vector (morphology, bionomics, intrinsic phase dengue virus and some research conducted as dengue vaccine discovery efforts. Conclusion: The availability of information about dengue on YouTube social media is still very deficient. Recommendation: YouTube has the potential of social media as a medium for disseminating health promotion information about dengue.

Dengue-yellow fever sera cross-reactivity; challenges for diagnosis

OpenAIRE

Houghton-Triviño, Natalia; Montaña, Diana; Castellanos, Jaime

2008-01-01

Objective The Flavivirus genera share epitopes inducing cross-reactive antibodies leading to great difficulty in differentially diagnosing flaviviral infections. This work was aimed at evaluating the complexity of dengue and yellow fever serological differential diagnosis. Material and methods Dengue antibody capture ELISA and a yellow fever neutralisation test were carried out on 13 serum samples obtained from yellow fever patients, 20 acute serum samples from dengue patients and 19 voluntan...

THROMBOCYTOPENIA IN DENGUE HAEMORRHAGIC FEVER

Directory of Open Access Journals (Sweden)

I Wayan Putu Sutirta-Yasa

2013-04-01

Full Text Available The incidence and geographical distribution of dengue has gradually increased during the past decade. Today, dengue is considered one of the most important arthropod-borne viral diseasases in humans in term of morbidity and mortality. Dengue infection   a potential life-threatening dengue hemorrhagic fever (DHF / dengue shock syndrome(DSS, characterized by thrombocytopenia and increased vascular permiability. Thrombocytopenia causes bleeding, but in   DHF patients with thrombocytopenia do not always develop bleeding manifestation. The pathogenesis of thrombocytopenia are not cleared. Multiple factors  may be involved in the machanisms leading to thrombocytopenia in DHF/DSS patients.

Identification of New Protein Interactions between Dengue Fever Virus and Its Hosts, Human and Mosquito

Science.gov (United States)

Mairiang, Dumrong; Zhang, Huamei; Sodja, Ann; Murali, Thilakam; Suriyaphol, Prapat; Malasit, Prida; Limjindaporn, Thawornchai; Finley, Russell L.

2013-01-01

The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host – dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies. PMID:23326450

Identification of new protein interactions between dengue fever virus and its hosts, human and mosquito.

Science.gov (United States)

Mairiang, Dumrong; Zhang, Huamei; Sodja, Ann; Murali, Thilakam; Suriyaphol, Prapat; Malasit, Prida; Limjindaporn, Thawornchai; Finley, Russell L

2013-01-01

The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host - dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies.

Identification of new protein interactions between dengue fever virus and its hosts, human and mosquito.

Directory of Open Access Journals (Sweden)

Dumrong Mairiang

Full Text Available The four divergent serotypes of dengue virus are the causative agents of dengue fever, dengue hemorrhagic fever and dengue shock syndrome. About two-fifths of the world's population live in areas where dengue is prevalent, and thousands of deaths are caused by the viruses every year. Dengue virus is transmitted from one person to another primarily by the yellow fever mosquito, Aedes aegypti. Recent studies have begun to define how the dengue viral proteins interact with host proteins to mediate viral replication and pathogenesis. A combined analysis of these studies, however, suggests that many virus-host protein interactions remain to be identified, especially for the mosquito host. In this study, we used high-throughput yeast two-hybrid screening to identify mosquito and human proteins that physically interact with dengue proteins. We tested each identified host protein against the proteins from all four serotypes of dengue to identify interactions that are conserved across serotypes. We further confirmed many of the interactions using co-affinity purification assays. As in other large-scale screens, we identified some previously detected interactions and many new ones, moving us closer to a complete host - dengue protein interactome. To help summarize and prioritize the data for further study, we combined our interactions with other published data and identified a subset of the host-dengue interactions that are now supported by multiple forms of evidence. These data should be useful for understanding the interplay between dengue and its hosts and may provide candidates for drug targets and vector control strategies.

Dengue Haemorrhagic Fever presenting as Acute Abdomen

OpenAIRE

Al-Araimi, Hanaa; Al-Jabri, Amal; Mehmoud, Arshad; Al-Abri, Seif

2011-01-01

We describe a case of a 38 year-old Sri Lankan female who was referred to the surgeon on call with a picture of acute abdomen. She presented with a three-day history of fever, headache, abdominal pain and diarrhoea; however, the physical examination was not consistent with acute abdomen. Her platelet count was 22 ×109/L. A diagnosis of dengue haemorrhagic fever (DHF) was made and dengue serology was positive. Dengue epidemics have been associated with a variety of gastrointestinal symptoms an...

Anamnestic immune response to dengue and decreased severity of yellow fever

Directory of Open Access Journals (Sweden)

Ricardo O Izurieta

2009-01-01

Full Text Available A protective immunity against yellow fever, from cross-reactive dengue antibodies, has been hypothesized as an explanation for the absence of yellow fever in Southern Asia where dengue immunity is almost universal. This study evaluates the association between protective immunity from cross-reactive dengue antibodies with yellow fever infection and severity of the disease. The study population consisted of military personnel of a jungle garrison and its detachments located in the Ecuadorian Amazonian rainforest. The cross-sectional study employed interviews as well as seroepidemiological methods. Humoral immune response to yellow fever, Mayaro, Venezuelan equine encephalitis, Oropouche, and dengue 2 infections was assessed by evaluating IgM and IgG specific antibodies. Log-linear regression analysis was used to evaluate age and presence of antibodies, against dengue type 2 virus, as predictors of yellow fever infection or severe disease. During the seroepidemiological survey, presence of dengue antibodies among yellow fever cases were observed in 77.3% cases from the coastal region, where dengue is endemic, 14.3% cases from the Amazon and 16.7 % cases from the Andean region. Dengue cross-reactive antibodies were not significantly associated with yellow fever infection but significantly associated with severity of the disease. The findings of this study suggest that previous exposure to dengue infection may have induced an anamnestic immune response that did not prevent yellow fever infection but greatly reduced the severity of the disease.

Frequency of splenomegaly in dengue fever in children

International Nuclear Information System (INIS)

Javaid, A.; Asghar, M.; Butt, M.A.

2015-01-01

Dengue Fever is caused by arthropod born viruses.According to World Health Organization approximately 50-100 million infections of dengue fever occur yearly. Objective of this study was to determine the frequency of splenomegaly in dengue fever in children. Methods: This cross sectional study was conducted at the Department of Paediatrics, Allied Hospital, Faisalabad, during a period from June 2012 to May 2013 by including 93 Children, aged 4-14 years presenting with fever of less than 14 days with thrombocytopenia and positive IgM or IgM and IgG dengue antibodies by ELISA. Patients were thoroughly evaluated by detailed history and clinical examination. Ultrasonography of the patients was performed to confirm the splenomegaly. The data was analysed to determine the frequency and percentage of disease. Results: Out of 93 children, 51 (54.8%) were male and 42 (45.2%) were female. The most common clinical presentation was noted is chills and rigors in 80 (86.02%). Unusual clinical features were encephalopathy in 37 (39.78%) followed by bleeding manifestations and upper respiratory tract infection (upper RTI). Splenomegaly was seen in 45 (48.4%) children. Conclusion: Dengue fever is increasingly presenting with atypical presentation like splenomegaly, encephalopathy, bleeding manifestations and upper RTI. (author)

[An imported dengue Fever case in Turkey and review of the literature].

Science.gov (United States)

Uyar, Yavuz; Aktaş, Eray; Yağcı Çağlayık, Dilek; Ergönül, Onder; Yüce, Ayşe

2013-01-01

Dengue fever is an acute viral disease that can affect all age groups in tropical and subtropical countries. The predominant vectors are the mosquitoes namely Aedes aegypti and A.albopictus. Although there have been no case reports in Turkey due to DF, there is seroepidemiological evidence indicating the presence of Dengue virus (DENV) in Turkey. In this case report we presented an imported dengue fever case. The patient was 40 years old, previously healthy male, Switzerland citizen. He had immigrated from Dubai to India two weeks ago and after one week from immigration he attended to a hospital in India because of high fever. The NS1 antigen test (Bio-Rad Laboratories, USA) was found positive and the patient was followed-up with diagnosis of dengue fever in India. During his visit to Turkey, he attended to the hospital for a routine control and his analysis revealed thrombocytopenia (PLT: 48.000/µl), leukopenia (white blood cell: 2800/µL) and elevated liver enzymes (AST: 76 U/L, ALT: 83 U/L). Fever was not detected in follow-up. The patient had petechial rash on his lower extremities. white blood cell and PLT count increased to 4100/µl and 93.000/µl, respectively. Liver function tests revealed a decrease in AST (63 U/L) and ALT (78 U/L) on the third day. The PLT count increased to 150.000/ml. Since the patient had no fever and had normal physical and laboratory findings, he was discharged from the hospital. For the confirmation of dengue fever diagnosis the serum sample was sent to National Public Health Center, Virology Reference and Research Laboratory where IgM and IgG antibodies against DENV types 1-4 were investigated by indirect immunofluorescence method (Euroimmun, Germany). The serum sample yielded positive result at the dilutions of 1/1000 for IgM and 1/10.000 for IgG. The last dilution of type 3 DENV IgM and IgG were determined high density of fluorescein, thus the serotype was identified as "DENV type 3". Travel-related diseases become important

Deteksi Penyakit Dengue Hemorrhagic Fever dengan Pendekatan One Class Classification

Directory of Open Access Journals (Sweden)

Zida Ziyan Azkiya

2017-10-01

Full Text Available Two class classification problem maps input into two target classes. In certain cases, training data is available only in the form of a single class, as in the case of Dengue Hemorrhagic Fever (DHF patients, where only data of positive patients is available. In this paper, we report our experiment in building a classification model for detecting DHF infection using One Class Classification (OCC approach. Data from this study is sourced from laboratory tests of patients with dengue fever. The OCC methods compared are One-Class Support Vector Machine and One-Class K-Means. The result shows SVM method obtained precision value = 1.0, recall = 0.993, f-1 score = 0.997, and accuracy of 99.7% while the K-Means method obtained precision value = 0.901, recall = 0.973, f- 1 score = 0.936, and accuracy of 93.3%. This indicates that the SVM method is slightly superior to K-Means for One-Class Classification of DHF patients.

Fundus Findings in Dengue Fever: A Case Report

Directory of Open Access Journals (Sweden)

Berna Şahan

2015-10-01

Full Text Available Dengue fever is a flavivirus infection transmitted through infected mosquitoes, and is endemic in Southeast Asia, Central and South America, the Pacific, Africa and the Eastern Mediterranean region. A 41-year-old male patient had visual impairment after travelling to Thailand, which is one of the endemic areas. Cotton wool spots were observed on fundus examination. Fundus fluorescein angiography showed minimal vascular leakage from areas near the cotton wool spots and dot hemorrhages in the macula. Dengue fever should be considered in patients with visual complaints who traveled to endemic areas of dengue fever. (Turk J Ophthalmol 2015; 45: 223-225

Health beliefs and practices related to dengue fever: a focus group study.

Science.gov (United States)

Wong, Li Ping; AbuBakar, Sazaly

2013-01-01

This qualitative study aimed to provide an in-depth understanding of the meaning of dengue fever (DF) amongst people living in a dengue endemic region, dengue prevention and treatment-seeking behaviours. The Health Belief Model was used as a framework to explore and understand dengue prevention behaviours. A total of 14 focus group discussions were conducted with 84 Malaysian citizens of different socio-demographic backgrounds between 16(th) December, 2011 and 12(th) May, 2012. The study revealed that awareness about DF and prevention measures were high. The pathophysiology of dengue especially dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) were rarely known; as a result, it was seen as deadly by some but was also perceived as easily curable by others without a basis of understanding. Young adults and elderly participants had a low perception of susceptibility to DF. In general, the low perceived susceptibility emerged as two themes, namely a perceived natural ability to withstand infection and a low risk of being in contact with the dengue virus vector, Aedes spp. mosquitoes. The barriers to sustained self-prevention against dengue prevention that emerged in focus groups were: i) lack of self-efficacy, ii) lack of perceived benefit, iii) low perceived susceptibility, and iv) unsure perceived susceptibility. Low perceived benefit of continued dengue prevention practices was a result of lack of concerted action against dengue in their neighborhood. Traditional medical practices and home remedies were widely perceived and experienced as efficacious in treating DF. Behavioural change towards attaining sustainability in dengue preventive practices may be enhanced by fostering comprehensive knowledge of dengue and a change in health beliefs. Wide use of unconventional therapy for DF warrants the need to enlighten the public to limit their reliance on unproven alternative treatments.

VECTOR RESISTANCE STATUS OF DENGUE HEMORRHAGIC FEVER (Aedes aegypti IN THE SIDOREJO DISTRICT SALATIGA CITY AGAINST TEMEPHOS (ORGANOPHOSPHATES

Directory of Open Access Journals (Sweden)

Ary Oktsari Yanti S

2014-06-01

Full Text Available One of the efforts to control the incidence of Dengue Hemorrhagic Fever (DHF is contrled thedengue vector larvae using larvasida. The most widely larvasida used to control larvae Ae.aegypti is temephos. In Indonesia 1% temephos (abate 1SG has been used since 1976, and since1980 has been used for the eradication program ofAe. aegypti larvae. The purpose of this studyis to determine the resistance status of vectors of dengue hemorrhagic fever (Ae. aegypti ofendemic, sporadic, and potentially in Sub District Sidorejo Salatiga City to temephos(organofosfat. This research was conducted using experimental research design (TrueExperiment, posttcst design with control groups (posttest-only Control Group Design. Thepopulation of the research were larvae of Ae. aegypti collected from the study area. Samples testlarvae were used of Ae. aegypti third and early fourth instars larvae which were maintenance ofthe first generation. The result showed that the mortality percentages of Ae. aegypti larvaeof endemic, sporadic and potential administratives against temephos using WHO standardconcentration (0,625; 0,125; 0,025 mg/1 indicates the mortality of Ae. aegypti larvae by 100%Based on the status resistance criteria, Ae. aegypti larvae from endemic, sporadic, and potentialadministratives of Sidorejo Sub-District, Salatiga City is still susceptible to temephos.Keywords : Status of resistance, Aedes aegypti. TemephosSalah satu upaya menurunkan Demam Berdarah Dengue (DBD adalah melaluipengcndalian jentik vektor DBD dengan larvasida. Larvasida yang digunakan untukmengcndalikan jentik Ae. aegypti adalah temephos. Temephos 1% (abate ISG sudah programdi Indonesia sejak 1976, scjak 1980 telah digunakan secara massal untuk programpemberantasan jentik Ae. aegypti. Tujuan penelitian ini adalah untuk mengetahui status resistensivektor demam berdarah dengue Ae. aegypti di kclurahan endemis, sporadis, dan potensialKecamatan Sidorejo Kota Salatiga terhadap temephos

Acute gingival bleeding as a complication of dengue hemorrhagic fever

Directory of Open Access Journals (Sweden)

Saif Khan

2013-01-01

Full Text Available Dengue fever is mosquito borne disease caused by dengue virus (DENV of Flaviviridae family. The clinical manifestations range from fever to severe hemorrhage, shock and death. Here, we report a case of 20-year-old male patient undergoing orthodontic treatment presenting with acute gingival bleeding with a history of fever, weakness, backache, retro orbital pain and ecchymosis over his right arm. The hematological investigations revealed anemia, thrombocytopenia and positive dengue non-structural protein-1 antigen and also positive immunoglobulin M and immunoglobulin G antibodies for DENV. Patient was diagnosed as a case of dengue hemorrhagic fever and was immediately referred for appropriate management. This case report emphasizes the importance of taking correct and thorough medical history.

Dengue Hemorrhagic Fever: Epidemiology, Pathogenesis, and Its Transmission Risk Factors

Directory of Open Access Journals (Sweden)

Aryu Candra

2010-12-01

Full Text Available Dengue hemorrhagic fever is an infectious disease resulting spectrum of clinical manifestations that vary from the lightest, dengue fever, hemorrhagic fever and dengue fever are accompanied by shock or dengue shock syndrome. Its caused by dengue virus, transmitted by Aedes mosquitoes. The case is spread in the tropics, especially in Southeast Asia, Central America, America and the Caribbean, many causes of death in children 90% of them attacking children under 15 years old. Until now pathogenesis is unclear. There are two theories or hypotheses immuno-patogenesis DHF and DSS is still controversial which secondary infections (secondary heterologus infection and antibody-dependent enhancement. Risk factors for dengue transmission are rapid urban population growth, mobilization of the population because of improved transportation facilities and disrupted or weakened so that population control. Another risk factor is poverty which result in people not has the ability to provide a decent home and healthy, drinking water supply and proper waste disposal.

Treatment of dengue fever

OpenAIRE

Rajapakse, Senaka; Rodrigo,Chaturaka; Rajapakse,Anoja Chamarie

2012-01-01

Senaka Rajapakse,1,2 Chaturaka Rodrigo,1 Anoja Rajapakse31Department of Clinical Medicine, Faculty of Medicine, University of Colombo, Sri Lanka; 2Lincoln County Hospital, United Lincolnshire NHS Trust, Lincoln, UK; 3Kings Mill Hospital, Sherwood Forest NHS Foundation Trust, Mansfield, UKAbstract: The endemic area for dengue fever extends over 60 countries, and approximately 2.5 billion people are at risk of infection. The incidence of dengue has multiplied many times over the last five decad...

An information value based analysis of physical and climatic factors affecting dengue fever and dengue haemorrhagic fever incidence

Directory of Open Access Journals (Sweden)

Tripathi Nitin

2005-06-01

Full Text Available Abstract Background Vector-borne diseases are the most dreaded worldwide health problems. Although many campaigns against it have been conducted, Dengue Fever (DF and Dengue Haemorrhagic Fever (DHF are still the major health problems of Thailand. The reported number of dengue incidences in 1998 for the Thailand was 129,954, of which Sukhothai province alone reported alarming number of 682. It was the second largest epidemic outbreak of dengue after 1987. Government arranges the remedial facilities as and when dengue is reported. But, the best way to control is to prevent it from happening. This will be possible only when knowledge about the relationship of DF/DHF with climatic and physio-environmental agents is discovered. This paper explores empirical relationship of climatic factors rainfall, temperature and humidity with the DF/DHF incidences using multivariate regression analysis. Also, a GIS based methodology is proposed in this paper to explore the influence of physio-environmental factors on dengue incidences. Remotely sensed data provided important data about physical environment and have been used for many vector borne diseases. Information Values (IV method was utilised to derive influence of various factors in the quantitative terms. Researchers have not applied this type of analysis for dengue earlier. Sukhothai province was selected for the case study as it had high number of dengue cases in 1998 and also due to its diverse physical setting with variety of land use/land cover types. Results Preliminary results demonstrated that physical factors derived from remotely sensed data could indicate variation in physical risk factors affecting DF/DHF. A composite analysis of these three factors with dengue incidences was carried out using multivariate regression analysis. Three empirical models ER-1, ER-2 and ER-3 were evaluated. It was found that these three factors have significant relation with DF/DHF incidences and can be related to

Can internet search queries be used for dengue fever surveillance in China?

Science.gov (United States)

Guo, Pi; Wang, Li; Zhang, Yanhong; Luo, Ganfeng; Zhang, Yanting; Deng, Changyu; Zhang, Qin; Zhang, Qingying

2017-10-01

China experienced an unprecedented outbreak of dengue fever in 2014, and the number of cases reached the highest level over the past 25 years. Traditional sentinel surveillance systems of dengue fever in China have an obvious drawback that the average delay from receipt to dissemination of dengue case data is roughly 1-2 weeks. In order to exploit internet search queries to timely monitor dengue fever, we analyzed data of dengue incidence and Baidu search query from 31 provinces in mainland China during the period of January 2011 to December 2014. We found that there was a strong correlation between changes in people's online health-seeking behavior and dengue fever incidence. Our study represents the first attempt demonstrating a strong temporal and spatial correlation between internet search trends and dengue epidemics nationwide in China. The findings will help the government to strengthen the capacity of traditional surveillance systems for dengue fever. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Impaired fibrinolysis in the pathogenesis of dengue hemorrhagic fever.

NARCIS (Netherlands)

Gorp, E. van; Setiati, T.E.; Mairuhu, A.T.; Suharti, C.; Cate, H.H.; Dolmans, W.M.V.; Meer, J.W.M. van der; Hack, C.E.; Brandjes, D.P.

2002-01-01

The mechanisms contributing to bleeding complications in dengue hemorrhagic fever were studied by investigating the pattern of activation of the coagulation and fibrinolytic systems in 50 children with severe dengue hemorrhagic fever. Thirteen patients (26%) died, and activation of coagulation was

Impaired fibrinolysis in the pathogenesis of dengue hemorrhagic fever

NARCIS (Netherlands)

van Gorp, Eric C. M.; Setiati, Tatty E.; Mairuhu, Albert T. A.; Suharti, Catharina; Cate Ht, Hugo ten; Dolmans, Wil M. V.; van der Meer, Jos W. M.; Hack, C. Erik; Brandjes, Dees P. M.

2002-01-01

The mechanisms contributing to bleeding complications in dengue hemorrhagic fever were studied by investigating the pattern of activation of the coagulation and fibrinolytic systems in 50 children with severe dengue hemorrhagic fever. Thirteen patients (26%) died, and activation of coagulation was

Active metabolites of the genus Piper against Aedes aegypti: natural alternative sources for dengue vector control

OpenAIRE

Marques, André M; Kaplan, Maria Auxiliadora C

2015-01-01

The mosquito, Aedes aegypti, is the principal vector of the viruses responsible for dengue and dengue hemorrhagic fevers. The mosquito is widespread throughout tropical and sub-tropical regions; its prevalence makes dengue one of the most important mosquito-borne viral diseases in the world occurring annually in more than 100 endemic countries. Because blood is essential to their development cycle, the Aedes species maintains a close association with humans and their dwellings. Fittingly, the...

Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.

Science.gov (United States)

Schmidt, Wolf-Peter; Suzuki, Motoi; Thiem, Vu Dinh; White, Richard G; Tsuzuki, Ataru; Yoshida, Lay-Myint; Yanai, Hideki; Haque, Ubydul; Tho, Le Huu; Anh, Dang Duc; Ariyoshi, Koya

2011-08-01

Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk. We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013). We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks. Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary.

Population density, water supply, and the risk of dengue fever in Vietnam: cohort study and spatial analysis.

Directory of Open Access Journals (Sweden)

Wolf-Peter Schmidt

2011-08-01

Full Text Available Aedes aegypti, the major vector of dengue viruses, often breeds in water storage containers used by households without tap water supply, and occurs in high numbers even in dense urban areas. We analysed the interaction between human population density and lack of tap water as a cause of dengue fever outbreaks with the aim of identifying geographic areas at highest risk.We conducted an individual-level cohort study in a population of 75,000 geo-referenced households in Vietnam over the course of two epidemics, on the basis of dengue hospital admissions (n = 3,013. We applied space-time scan statistics and mathematical models to confirm the findings. We identified a surprisingly narrow range of critical human population densities between around 3,000 to 7,000 people/km² prone to dengue outbreaks. In the study area, this population density was typical of villages and some peri-urban areas. Scan statistics showed that areas with a high population density or adequate water supply did not experience severe outbreaks. The risk of dengue was higher in rural than in urban areas, largely explained by lack of piped water supply, and in human population densities more often falling within the critical range. Mathematical modeling suggests that simple assumptions regarding area-level vector/host ratios may explain the occurrence of outbreaks.Rural areas may contribute at least as much to the dissemination of dengue fever as cities. Improving water supply and vector control in areas with a human population density critical for dengue transmission could increase the efficiency of control efforts. Please see later in the article for the Editors' Summary.

Potential distribution of dengue fever under scenarios of climate change and economic development.

Science.gov (United States)

Aström, Christofer; Rocklöv, Joacim; Hales, Simon; Béguin, Andreas; Louis, Valerie; Sauerborn, Rainer

2012-12-01

Dengue fever is the most important viral vector-borne disease with ~50 million cases per year globally. Previous estimates of the potential effect of global climate change on the distribution of vector-borne disease have not incorporated the effect of socioeconomic factors, which may have biased the results. We describe an empirical model of the current geographic distribution of dengue, based on the independent effects of climate and gross domestic product per capita (GDPpc, a proxy for socioeconomic development). We use the model, along with scenario-based projections of future climate, economic development, and population, to estimate populations at risk of dengue in the year 2050. We find that both climate and GDPpc influence the distribution of dengue. If the global climate changes as projected but GDPpc remained constant, the population at risk of dengue is estimated to increase by about 0.28 billion in 2050. However, if both climate and GDPpc change as projected, we estimate a decrease of 0.12 billion in the population at risk of dengue in 2050. Empirically, the geographic distribution of dengue is strongly dependent on both climatic and socioeconomic variables. Under a scenario of constant GDPpc, global climate change results in a modest but important increase in the global population at risk of dengue. Under scenarios of high GDPpc, this adverse effect of climate change is counteracted by the beneficial effect of socioeconomic development.

Spontaneous muscle hematomas in a patient with Dengue hemorrhagic fever

Directory of Open Access Journals (Sweden)

Jency Maria Koshy

2014-01-01

Full Text Available Dengue hemorrhagic fever (DHF and Dengue shock syndrome manifest in various forms, ranging from petechial skin hemorrhage to life threatening cerebral, pulmonary, gastrointestinal and genitourinary hemorrhages. However it is very rare to have muscle hematomas in DHF. We report a rare case of spontaneous Iliopsoas hematoma complicating Dengue hemorrhagic fever.

Modeling the Geographic Consequence and Pattern of Dengue Fever Transmission in Thailand.

Science.gov (United States)

Bekoe, Collins; Pansombut, Tatdow; Riyapan, Pakwan; Kakchapati, Sampurna; Phon-On, Aniruth

2017-05-04

Dengue fever is one of the infectious diseases that is still a public health problem in Thailand. This study considers in detail, the geographic consequence, seasonal and pattern of dengue fever transmission among the 76 provinces of Thailand from 2003 to 2015. A cross-sectional study. The data for the study was from the Department of Disease Control under the Bureau of Epidemiology, Thailand. The quarterly effects and location on the transmission of dengue was modeled using an alternative additive log-linear model. The model fitted well as illustrated by the residual plots and the  Again, the model showed that dengue fever is high in the second quarter of every year from May to August. There was an evidence of an increase in the trend of dengue annually from 2003 to 2015. There was a difference in the distribution of dengue fever within and between provinces. The areas of high risks were the central and southern regions of Thailand. The log-linear model provided a simple medium of modeling dengue fever transmission. The results are very important in the geographic distribution of dengue fever patterns.

Understanding the Impact of Anthropogenic and Environmental Changes on Dengue Fever Cases in Puerto Rico

Science.gov (United States)

Akanda, A. S.; Serman, E. A.; Couret, J.; Puggioni, G.; Ginsberg, H. S.

2016-12-01

Worldwide, there are an estimated 50-100 million cases of dengue fever each year, roughly 30 times the number of cases as 50 years ago. Dengue was introduced to Puerto Rico (PR) in 1963 and it has experienced epidemic activity ever since. There have been 4 large epidemics since 1990, the most recent in 2010 where almost 27,000 cases were reported. Vaccine development remains in the testing stages, and years away from mass distribution. Effective control thus depends on our understanding of the complex relationships between environmental and anthropogenic factors, mosquito vector ecology, and disease epidemiology. Dengue virus is primarily transmitted by Aedes aegypti mosquitoes, which also carry the Zika virus, and humans in urban environments are their preferred hosts. The purpose of our analysis is to identify trends between anthropogenic and environmental changes and dengue fever cases in PR over the past 15 years. Data on housing and population density, percent impervious surface, and percent tree canopy at the municipality level were procured from the U.S. Census Bureau and the Multi-Resolution Land Characteristics Consortium (MLRC) project, respectively. Land cover data from the National Land Cover Database, created by USGS and NOAA, as well as environmental data from the National Climatic Data Center (NCDC), were also used. Smaller land cover and green space analysis studies have been performed for PR, but this is the first study to consider the island as a whole, and in six distinct regions, with regards to increases in dengue fever cases. The results from this study can be used to understand the effects of urbanization and climate change on vector-borne disease transmission in PR and to project the impact of growing sub-urban and urban areas on dengue cases in coming years. Our results could also be used to assess Dengue and Zika transmission in growing megacites of the world, where urban slums provide a favorable habitat for Ae. aegypti and foster

Analysis of Impact of Geographical Environment and Socio-economic Factors on the Spatial Distribution of Kaohsiung Dengue Fever Epidemic

Science.gov (United States)

Hsu, Wei-Yin; Wen, Tzai-Hung; Yu, Hwa-Lung

2013-04-01

Taiwan is located in subtropical and tropical regions with high temperature and high humidity in the summer. This kind of climatic condition is the hotbed for the propagation and spread of the dengue vector mosquito. Kaohsiung City has been the worst dengue fever epidemic city in Taiwan. During the study period, from January 1998 to December 2011, Taiwan CDC recorded 7071 locally dengue epidemic cases in Kaohsiung City, and the number of imported case is 118. Our research uses Quantile Regression, a spatial infection disease distribution, to analyze the correlation between dengue epidemic and geographic environmental factors and human society factors in Kaohsiung. According to our experiment statistics, agriculture and natural forest have a positive relation to dengue fever(5.5~34.39 and 3.91~15.52). The epidemic will rise when the ratio for agriculture and natural forest increases. Residential ratio has a negative relation for quantile 0.1 to 0.4(-0.005~-0.78), and a positive relation for quantile 0.5 to0.9(0.01~18.0) . The mean income is also a significant factor in social economy field, and it has a negative relation to dengue fever(-0.01~-0.04). Conclusion from our research is that the main factor affecting the degree of dengue fever in predilection area is the residential proportion and the ratio of agriculture and natural forest plays an important role affecting the degree of dengue fever in non predilection area. Moreover, the serious epidemic area located by regression model is the same as the actual condition in Kaohsiung. This model can be used to predict the serious epidemic area of dengue fever and provide some references for the Health Agencies

Acute atrial fibrillation during dengue hemorrhagic fever

Directory of Open Access Journals (Sweden)

Henrique Horta Veloso

Full Text Available Dengue fever is a viral infection transmitted by the mosquito, Aedes aegypti. Cardiac rhythm disorders, such as atrioventricular blocks and ventricular ectopic beats, appear during infection and are attributed to viral myocarditis. However, supraventricular arrhythmias have not been reported. We present a case of acute atrial fibrillation, with a rapid ventricular rate, successfully treated with intravenous amiodarone, in a 62-year-old man with dengue hemorrhagic fever, who had no structural heart disease.

Acute atrial fibrillation during dengue hemorrhagic fever

Directory of Open Access Journals (Sweden)

Veloso Henrique Horta

2003-01-01

Full Text Available Dengue fever is a viral infection transmitted by the mosquito, Aedes aegypti. Cardiac rhythm disorders, such as atrioventricular blocks and ventricular ectopic beats, appear during infection and are attributed to viral myocarditis. However, supraventricular arrhythmias have not been reported. We present a case of acute atrial fibrillation, with a rapid ventricular rate, successfully treated with intravenous amiodarone, in a 62-year-old man with dengue hemorrhagic fever, who had no structural heart disease.

Demographic and clinico-epidemiological features of dengue fever in Faisalabad, Pakistan.

Directory of Open Access Journals (Sweden)

Faiz Ahmed Raza

Full Text Available This cross-sectional study was carried out to explore the epidemiological and clinical features of dengue fever in Faisalabad, Pakistan during 2011 and 2012. During the study period, anti-dengue IgM positive cases were reported in the post-monsoon period during the months of August-December. Certain hotspots for the dengue infection were identified in the city that coincide with the clusters of densely populated urban regions of the city. Out of total 299 IgM positive patients (male 218 and female 81; there were 239 dengue fever (DF and 60 dengue hemorrhagic fever (DHF patients. There was decrease in the median age of dengue patients from 31 years in 2011 to 21.5 years in 2012 (p<0.001. Abdominal pain was seen in 35% DHF patients followed by nausea in 28.3%, epistaxis in 25% and rash in 20% patients (p<0.05. Patients reported to be suffering from high-grade fever for an average of 8.83 days in DHF as compared to 5.82 days in DF before being hospitalized. Co-morbidities were found to be risk factor for the development of DHF in dengue patients. Clinical and laboratory features of dengue cases studied could be used for the early identification of patients at risk of severe dengue fever.

Retrospective search for dengue vector mosquito Aedes albopictus in areas visited by a German traveler who contracted dengue in Japan

Directory of Open Access Journals (Sweden)

Mutsuo Kobayashi

2014-09-01

Full Text Available A German traveler developed dengue fever in late August 2013, following a direct flight from Germany. Autochthonous dengue virus (DENV infection has not been reported in Japan. To evaluate the risk of autochthonous DENV transmission in Japan, the authors performed a retrospective search of the five areas visited by the German patient to determine the population density of dengue vector mosquito, Aedes albopictus. The annual mean temperature of each area was higher than 12 °C, which is considered suitable for the establishment of A. albopictus populations. Our retrospective search revealed the population density of A. albopictus to be high in the urban areas of Japan.

Application of Artificial Neural Networks for Dengue Fever Outbreak Predictions in the Northwest Coast of Yucatan, Mexico and San Juan, Puerto Rico

Directory of Open Access Journals (Sweden)

Abdiel E. Laureano-Rosario

2018-01-01

Full Text Available Modelling dengue fever in endemic areas is important to mitigate and improve vector-borne disease control to reduce outbreaks. This study applied artificial neural networks (ANNs to predict dengue fever outbreak occurrences in San Juan, Puerto Rico (USA, and in several coastal municipalities of the state of Yucatan, Mexico, based on specific thresholds. The models were trained with 19 years of dengue fever data for Puerto Rico and six years for Mexico. Environmental and demographic data included in the predictive models were sea surface temperature (SST, precipitation, air temperature (i.e., minimum, maximum, and average, humidity, previous dengue cases, and population size. Two models were applied for each study area. One predicted dengue incidence rates based on population at risk (i.e., numbers of people younger than 24 years, and the other on the size of the vulnerable population (i.e., number of people younger than five years and older than 65 years. The predictive power was above 70% for all four model runs. The ANNs were able to successfully model dengue fever outbreak occurrences in both study areas. The variables with the most influence on predicting dengue fever outbreak occurrences for San Juan, Puerto Rico, included population size, previous dengue cases, maximum air temperature, and date. In Yucatan, Mexico, the most important variables were population size, previous dengue cases, minimum air temperature, and date. These models have predictive skills and should help dengue fever mitigation and management to aid specific population segments in the Caribbean region and around the Gulf of Mexico.

A hospital-based study of hepatic dysfunction in children with dengue fever

Directory of Open Access Journals (Sweden)

Surjeet Singh

2015-12-01

Full Text Available Objective: To study the hepatic dysfunction in children with dengue infection and find out its correlation with the severity of dengue fever. Methods: Seventy-two cases of dengue fever as per the World Health Organization aged from 2 months to 18 years of age guidelines serologically confirmed by dengue NS1 antigen detection or dengue IgM capture ELISA were studied for their hepatic dysfunction after excluding malaria, enteric fever, hepatitis A and hepatitis B. The duration of the study was from April 2013 to March 2014. Results: These 72 cases were grouped into severe dengue, dengue fever with warning sign and dengue fever without warning sign as per the World Health Organization guidelines. The spectrums of hepatic manifestations included hepatomegaly (66%, hepatic tenderness (44%, jaundice (9.72%, raised levels of aspartate transaminase (86%, alanine transaminase (90%, alkaline phosphatase (39%, prolonged prothrombin time (11% and reduced levels of serum albumin (66%. Conclusions: Tender hepatomegaly and elevated liver enzymes were seen more frequently in severe dengue. There was significant derangement between liver function and tender hepatomegaly. Altered liver function may be evident even in the absence of hepatomegaly.

Oral receptivity of Aedes aegypti from Cape Verde for yellow fever, dengue, and chikungunya viruses.

Science.gov (United States)

Vazeille, Marie; Yébakima, André; Lourenço-de-Oliveira, Ricardo; Andriamahefazafy, Barrysson; Correira, Artur; Rodrigues, Julio Monteiro; Veiga, Antonio; Moreira, Antonio; Leparc-Goffart, Isabelle; Grandadam, Marc; Failloux, Anna-Bella

2013-01-01

At the end of 2009, 21,313 cases of dengue-3 virus (DENV-3) were reported in the islands of Cape Verde, an archipelago located in the Atlantic Ocean 570 km from the coast of western Africa. It was the first dengue outbreak ever reported in Cape Verde. Mosquitoes collected in July 2010 in the city of Praia, on the island of Santiago, were identified morphologically as Aedes aegypti formosus. Using experimental oral infections, we found that this vector showed a moderate ability to transmit the epidemic dengue-3 virus, but was highly susceptible to chikungunya and yellow fever viruses.

Dengue fever in patients admitted in tertiary care hospitals in Pakistan

International Nuclear Information System (INIS)

Munir, M. A.; Saqib, M. A. N.; Qureshi, H.; Alam, S. E.; Arif, A.; Khan, Z. U.; Saeed, Q.; Iqbal, R.

2014-01-01

Objectives: To assess the gaps in the diagnosis and management of dengue fever cases. Methods: The retrospective descriptive analytical study was done with a case record analysis of patients with dengue fever admitted from January to December 2010 at five tertiary care hospitals in different Pakistani cities. Using a questionnaire, information was gathered on demography, haematological profile, management, use of blood and platelet transfusions and the outcome. For comparison, data of serologically-confirmed dengue patients from a private laboratory in Islamabad was collected to see the age, gender and month-wise distribution of cases tested over the same period. SPSS 16 was used for statistical analysis. Results: Out of the 841 confirmed dengue cases, 514 (79%) were males and 139 (21%) females. The overall mean age was 31.3+-14.0 years. Dengue fever was seen in 653 (78%) and dengue haemorrhagic fever (DHF) in 188 (22%) patients. Most cases were between 20 and 49 years of age. A gradual increase in dengue fever and dengue haemorrhagic fever was seen from August, with a peak in October/November. Tourniquet test was done only in 20 (2.3%) cases, out of which 11 (55%) were positive and 9 (45%) were negative. Serial haematocrit was not done in any case. Total deaths were 5 (0.6%). Conclusions: Most cases were seen in October/November with the majority being in the 20-39 age group. Tourniquet test and serial haematocrit were infrequently used. No standard national guidelines were employed. (author)

Secondary bacteraemia in adult patients with prolonged dengue fever.

Science.gov (United States)

Premaratna, R; Dissanayake, D; Silva, F H D S; Dassanayake, M; de Silva, H J

2015-03-01

Although dengue management guidelines do not advice on use of antibiotics in dengue shock syndrome, unrecognised bactraemia is likely to contribute to morbidity and mortality. To assess the occurance of secondary bacteraemia in adult patients with prolonged dengue fever. A prospective study was conducted recruiting patients with confirmed acute dengue infection who had prolonged fever (>5 days). Two sets of blood cultures were taken in such patients prior to institution of antibiotic therapy. Demographic, clinical, haematological and biochemical parameters were recorded. Development of ascites and pleural effusions were detected using ultrasonography. Fourty patients (52.5% males) with a mean age of 29.8 years (SD 13.6) were studied. The average duration of fever was 7.9 days (SD 1.8). Ten patients (25%) had bacterial isolates in their blood cultures; Staphylococcus aureus (n=2), coliforms (n=3), pseudomonas (n=1) and 4 had mixed growths. The culture positive group had severe body aches at admission and higher fever, third space fluid accumulation, a significant drop in platelets and a higher CRP. A quarter of dengue patients with prolonged fever had a bacterial isolate. Culture positive patients appeared more ill with body aches and had higher degrees of fever during the latter part of the illness. Increased vascular permeability may predispose to bacterial seepage into blood. Although white cell count is not helpful in detecting bacteraemia, low platelet count and elevation of CRP seem to be helpful.

Zoonotic and vector borne agents causing disease in adult patients hospitalized due to fever of unknown origin in Thailand

Directory of Open Access Journals (Sweden)

Soawapak Hinjoy

2017-10-01

Full Text Available Objective: To determine the etiologic agents of fever of unknown origin among populations in agricultural communities and to assess the possible risk factors for zoonotic infections. Methods: Hospitalized patients with fever of unknown origin under physician care were asked to participate and provide blood samples for laboratory tests and screening for endemic diseases at the hospitals. Samples were stored at –80 °C until they were tested at Chulalongkorn University to identify additional pathogens. Results: We were able to identify the etiologic agents in 24.6% of the 463 enrolled patients. Zoonotic and vector borne agents were confirmed in 59 cases (12.7%. Dengue virus (7.3% was the most frequently detected disease followed by scrub typhus (3.2%. There were two cases of comorbidities of scrub typhus and dengue fever. The other six cases of zoonoses were leptospirosis, melioidosis, and Streptococcus suis infections. Patients with zoonotic/vector borne agents noticed rats in their houses and reported having contact with livestock feces more frequently than those patients without zoonotic/vector borne agents. Conclusions: Dengue virus and scrub typhus were mostly detected in the rainy season. During this specific season, clinicians should raise awareness of those diseases when any patients are admitted to the hospital with fever of an unidentified source.

Dengue Fever: Causes, Complications, and Vaccine Strategies

Directory of Open Access Journals (Sweden)

Niyati Khetarpal

2016-01-01

Full Text Available Dengue is a highly endemic infectious disease of the tropical countries and is rapidly becoming a global burden. It is caused by any of the 4 serotypes of dengue virus and is transmitted within humans through female Aedes mosquitoes. Dengue disease varies from mild fever to severe conditions of dengue hemorrhagic fever and shock syndrome. Globalization, increased air travel, and unplanned urbanization have led to increase in the rate of infection and helped dengue to expand its geographic and demographic distribution. Dengue vaccine development has been a challenging task due to the existence of four antigenically distinct dengue virus serotypes, each capable of eliciting cross-reactive and disease-enhancing antibody response against the remaining three serotypes. Recently, Sanofi Pasteur’s chimeric live-attenuated dengue vaccine candidate has been approved in Mexico, Brazil, and Philippines for usage in adults between 9 and 45 years of age. The impact of its limited application to the public health system needs to be evaluated. Simultaneously, the restricted application of this vaccine candidate warrants continued efforts in developing a dengue vaccine candidate which is additionally efficacious for infants and naïve individuals. In this context, alternative strategies of developing a designed vaccine candidate which does not allow production of enhancing antibodies should be explored, as it may expand the umbrella of efficacy to include infants and naïve individuals.

How does the dengue vector mosquito Aedes albopictus respond to global warming?

OpenAIRE

Jia, Pengfei; Chen, Xiang; Chen, Jin; Lu, Liang; Liu, Qiyong; Tan, Xiaoyue

2017-01-01

Background Global warming has a marked influence on the life cycle of epidemic vectors as well as their interactions with human beings. The Aedes albopictus mosquito as the vector of dengue fever surged exponentially in the last decade, raising ecological and epistemological concerns of how climate change altered its growth rate and population dynamics. As the global warming pattern is considerably uneven across four seasons, with a confirmed stronger effect in winter, an emerging need arises...

Dengue e dengue hemorrágico: aspectos do manejo na unidade de terapia intensiva Dengue and dengue hemorrhagic fever: management issues in an intensive care unit

Directory of Open Access Journals (Sweden)

Sunit Singhi

2007-05-01

this review, a literature search was made on Pubmed and on the World Health Organization (WHO and PAHO websites using the terms dengue and dengue shock syndrome. This information was complemented with personal practice. SUMMARY OF THE FINDINGS: Dengue is the most important arthropod-borne viral disease of humans. Its presentation is protean and varies from an undifferentiated viral syndrome to hemorrhagic fever and severe shock. Dengue fever is a self-limiting, nonspecific illness characterized by fever, headache, myalgia, and constitutional symptoms. Its severe forms (hemorrhagic fever and shock syndrome may lead to multisystem involvement and death. Early diagnosis, close monitoring for deterioration and response to treatment are necessary in all cases. WHO has provided a stepwise approach to management that is useful for milder forms and early shock. In the more severe forms aggressive fluid resuscitation and support for failing organs is necessary for the critically ill patient. Research addressing pathophysiological differences between dengue shock and septic shock, choice of fluids, inotropes and techniques of organ support are likely to yield benefits for the critically ill. CONCLUSIONS: There is no specific therapy for dengue infections. Good supportive care may be lifesaving, but ultimately initiatives aimed at vector control and prevention of mosquito bites may provide the greatest benefits.

[Coexistence of acute appendicitis and dengue fever: A case report].

Science.gov (United States)

Osuna-Ramos, Juan Fidel; Silva-Gracia, Carlos; Maya-Vacio, Gerardo Joel; Romero-Utrilla, Alejandra; Ríos-Burgueño, Efrén Rafael; Velarde-Félix, Jesús Salvador

2017-12-01

Dengue is the most important human viral disease transmitted by mosquitoes. It can be asymptomatic or it can present in any of its 3clinical forms: Dengue fever, dengue haemorrhagic fever and dengue shock syndrome. However, some atypical manifestations have been reported in surgical emergencies caused by acute appendicitis in patients with dengue fever. We report the case of an 18-year-old Mexican male who presented to the emergency department of the General Hospital of Culiacan, Sinaloa, with symptoms of dengue fever, accompanied by crampy abdominal pain with positive Rovsing and Dunphy signs. Dengue infection was confirmed by a positive NS1 antigen test performed by enzyme-linked immunosorbent assay. An abdominal ultrasound revealed an appendicular process; as the abdominal pain in the right side kept increasing, an open appendectomy was performed. Abundant inflammatory liquid was observed during the surgery, and the pathology laboratory reported an oedematous appendix with fibrinopurulent plaques, which agreed with acute ulcerative appendicitis. The patient was discharged fully recovered without complications during the follow-up period. Acute abdominal pain can be caused in some cases by dengue infection. This can be confusing, which can lead to unnecessary surgical interventions, creating additional morbidities and costs for the patient. This unusual and coincident acute appendicitis with dengue highlights the importance of performing careful clinical studies for appropriate decision making, especially in dengue endemic regions during an outbreak of this disease. Copyright © 2016 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

Dengue fever associated with acute scrotal oedema: two case reports

International Nuclear Information System (INIS)

Shamim, M.; Naqvi, S.Z.G.

2011-01-01

Scrotal oedema associated with dengue fever is a rare and self limiting condition resolving in a few days without any complication or sequelae. This is a report of two cases of dengue fever associated with acute scrotal and penile oedema. (author)

Clinical profile and outcome of Dengue fever cases.

Science.gov (United States)

Ratageri, Vinod H; Shepur, T A; Wari, P K; Chavan, S C; Mujahid, I B; Yergolkar, P N

2005-08-01

Dengue fever is on rise globally. In India, Dengue epidemics are expanding geographically, even into the rural areas. Dengue can present with varied manifestations. The mortality rate has been brought down with high index of suspicion, strict monitoring and proper fluid resuscitation. Herewith, we are presenting clinical features and outcome of Dengue cases seen in and around Hubli (North Karnataka).

Conhecimentos da população sobre dengue, seus vetores e medidas de controle em São José do Rio Preto, São Paulo The population's knowledge concerning dengue fever, vectors, and control measures in São José do Rio Preto, São Paulo state

Directory of Open Access Journals (Sweden)

Francisco Chiaravalloti Neto

1997-09-01

Full Text Available Desde 1985, vêm sendo realizadas, pelos órgãos de saúde, campanhas educativas institucionais para esclarecer a população sobre dengue, seus vetores e medidas de controle a serem adotadas. Para medir o nível de conhecimento da população de São José do Rio Preto, SP, aplicou-se, nos meses de abril e maio de 1995, um inquérito domiciliar em uma amostra de 537 residências da área urbana da cidade, entrevistando-se mesmo número de mulheres com perguntas sobre dengue, seus vetores e medidas de controle. Os conhecimentos demonstrados foram bastante satisfatórios, com exceção daqueles sobre a doença hemorrágica. Essa aquisição de conhecimentos, entretanto, não tem sido acompanhada da adoção das medidas de controle necessárias e não foi suficiente para a diminuição dos níveis de infestação dos vetores da dengue no município.Educational campaigns to inform the population about dengue fever, vectors, and related control measures have been carried out since 1985 by health services. In order to assess knowledge levels in São José do Rio Preto, São Paulo, a household survey was performed with a sample of 537 households in the urban area of São José do Rio Preto, São Paulo, in April and May 1995, where the same number of women were interviewed with questions about dengue fever, vectors, and control measures. Knowledge as displayed was satisfactory, except for that concerning hemorrhagic dengue. However, acquisition of knowledge was not followed by adoption of necessary control measures was insufficient to decrease infestation rates for dengue vectors in the city.

An economic evaluation of vector control in the age of a dengue vaccine.

Science.gov (United States)

Fitzpatrick, Christopher; Haines, Alexander; Bangert, Mathieu; Farlow, Andrew; Hemingway, Janet; Velayudhan, Raman

2017-08-01

Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito) vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control. We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs) and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical) highly targeted and low cost immunization strategy using a (non-hypothetical) medium-efficacy vaccine. Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price) reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates) relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations) and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine. Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted and low

An economic evaluation of vector control in the age of a dengue vaccine.

Directory of Open Access Journals (Sweden)

Christopher Fitzpatrick

2017-08-01

Full Text Available Dengue is a rapidly emerging vector-borne Neglected Tropical Disease, with a 30-fold increase in the number of cases reported since 1960. The economic cost of the illness is measured in the billions of dollars annually. Environmental change and unplanned urbanization are conspiring to raise the health and economic cost even further beyond the reach of health systems and households. The health-sector response has depended in large part on control of the Aedes aegypti and Ae. albopictus (mosquito vectors. The cost-effectiveness of the first-ever dengue vaccine remains to be evaluated in the field. In this paper, we examine how it might affect the cost-effectiveness of sustained vector control.We employ a dynamic Markov model of the effects of vector control on dengue in both vectors and humans over a 15-year period, in six countries: Brazil, Columbia, Malaysia, Mexico, the Philippines, and Thailand. We evaluate the cost (direct medical costs and control programme costs and cost-effectiveness of sustained vector control, outbreak response and/or medical case management, in the presence of a (hypothetical highly targeted and low cost immunization strategy using a (non-hypothetical medium-efficacy vaccine.Sustained vector control using existing technologies would cost little more than outbreak response, given the associated costs of medical case management. If sustained use of existing or upcoming technologies (of similar price reduce vector populations by 70-90%, the cost per disability-adjusted life year averted is 2013 US$ 679-1331 (best estimates relative to no intervention. Sustained vector control could be highly cost-effective even with less effective technologies (50-70% reduction in vector populations and in the presence of a highly targeted and low cost immunization strategy using a medium-efficacy vaccine.Economic evaluation of the first-ever dengue vaccine is ongoing. However, even under very optimistic assumptions about a highly targeted

A novel indirect ELISA for diagnosis of dengue fever

Directory of Open Access Journals (Sweden)

Rohan Narayan

2016-01-01

Full Text Available Background & objectives: Dengue fever (DF is associated with significant morbidity and mortality in the tropical and sub-tropical regions of the world. Since there are no effective antiviral drugs for treatment, clinicians often rely on the accurate diagnosis of dengue fever to begin supportive therapy at early stages of the illness. The objective of this study was to develop an in-house dengue virus serotype 2 (DENV-2 non-structural protein- 5 (NS5 based indirect ELISA. Methods: DENV-2 was raised in Vero cells and the viral proteins were separated and subsequently the NS5 protein was eluted. Serum samples from primary and secondary dengue fever patients; and acute and convalescent samples from Japanese encephalitis (JE and West Nile virus (WNV cases were used to validate the ELISA. Results: The assay was found to be 100 per cent specific in detecting DENV-2 specific antibodies from patient′s serum. However, in terms of sensitivity, the assay could detect IgM antibodies only from 90 per cent of the primary dengue samples. The IgM/IgG ratio of the primary and secondary samples was 7.24 and 0.64, respectively. Interpretation & conclusions: The results indicate that the DENV-2 NS5 ELISA is dengue group specific and can be used to differentiate dengue infection from other circulating Flavivirus infections. This NS5 ELISA can also be used to distinguish between primary and secondary dengue fever on the basis of IgM/IgG ratios. Further studies with larger sample sizes and different DENV serotypes are required to validate the ELISA.

Scanning electron microscopy of damage caused by Mesocyclops thermocyclopoides (Copepoda: Cyclopoidea on larvae of the Dengue fever vector Aedes aegypti (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Stefan Schaper

2006-09-01

Full Text Available Dengue fever is a mosquito-borne viral disease, whose main biological vector is Aedes aegypti. This mosquito colonizes tropical areas where the disease is endemic. The most obvious action against dengue is attacking its vector. Biological control appears to be an alternative approach, using natural enemies of the mosquitoes, such as predatory copepods. Thus, the morphological study of the damage caused by copepods is important to understand its predatory capacity. Twenty-five A. aegypti larvae were exposed to the copepod Mesocyclops thermocyclopoides and the damage caused by the copepods was evaluated using scanning electron microscopy. The larvae showed damage mainly at the anal segment, the siphon and the abdomen; only three attacks to the head were observed. The size of the siphon might be of importance in determining whether or not a copepod will attack a mosquito larva. Rev. Biol. Trop. 54 (3: 843-846. Epub 2006 Sept. 29.El dengue es una enfermedad viral transmitida por mosquitos, cuyo principal vector es Aedes aegypti. Este mosquito coloniza muchas áreas tropicales donde la enfermedad es endémica. La acción más obvia contra el dengue es el ataque a su vector. El control biológico parece una buena alternativa, empleando enemigos naturales de los mosquitos, como los copépodos. Por lo tanto, es importante el estudio morfológico del daño causado por los copépodos para comprender su capacidad depredadora. Veinticinco larvas de A. aegypti fueron expuestas a la actividad depredadora del copépodo Mesocyclops thermocyclopoides. Mediante microscopia electrónica de rastreo se evaluó el daño causado por los copépodos. Éstos atacaron principalmente el segmento anal, el sifón y el abdomen de las larvas; sólo vimos tres ataques a la cabeza. El tamaño del sifón podría ser de importancia para predecir si los copépodos pudiesen atacar larvas de determinado mosquito.

Isolated unilateral sixth cranial nerve palsy: A rare presentation of dengue fever

Directory of Open Access Journals (Sweden)

Yang Liang Boo

2016-11-01

Full Text Available Dengue fever is a common mosquito-borne viral infection endemic in tropical and subtropical countries. Neurological manifestations in dengue infection are relatively uncommon, and include encephalitis, encephalopathy, neuromuscular disorders and neuro-ocular disorders. Cranial mononeuropathy is a rare manifestation of dengue infection. A 40-year-old man was diagnosed with isolated, unilateral sixth cranial nerve palsy complicating dengue infection. The patient was managed accordingly, and full ocular recovery was observed. This was the first reported case of isolated sixth cranial nerve palsy associated with dengue fever in Malaysia. It is important for clinicians to consider dengue as a differential diagnosis in patients presenting with fever and sixth cranial nerve palsy.

An Accurate Gaussian Process-Based Early Warning System for Dengue Fever

OpenAIRE

Albinati, Julio; Meira Jr, Wagner; Pappa, Gisele Lobo

2016-01-01

Dengue fever is a mosquito-borne disease present in all Brazilian territory. Brazilian government, however, lacks an accurate early warning system to quickly predict future dengue outbreaks. Such system would help health authorities to plan their actions and to reduce the impact of the disease in the country. However, most attempts to model dengue fever use parametric models which enforce a specific expected behaviour and fail to capture the inherent complexity of dengue dynamics. Therefore, ...

CLINICAL AND HAEMATOLOGICAL PROFILE OF DENGUE FEVER IN A TERTIARY CARE HOSPITAL AT KAKINADA

Directory of Open Access Journals (Sweden)

Madhavi

2016-03-01

investigations were done: Blood counts, IgM Dengue. Clinically, patients were monitored and platelet count, haematocrit, Hess test were repeated daily. DATA ANALYSIS Data collected will be analysed by frequency, percentage and mean. Dengue-IgM Capture ELISA Detection of dengue virus specific IgM Antibodies in serum. RESULTS Male to female ratio was 1.5:1. Majority of the cases having dengue infection belong to the age group of 21-30 years, wherein 48% belong to 21-30 years’ group and 24% belong to 31-40 years’ group. All the cases had fever (100%. Other common signs and symptoms included are myalgia (85%, headache (80%, joint pains (76%, vomiting (60%, pain abdomen (54%, rash (46%, hepatomegaly (25%, bleeding (21% and shock (5%. Signs suggestive of plasma leakage such as pedal oedema (12%, ascites (20%, pleural effusion (26% were present. Hess test was positive in 20% of the patients. Thrombocytopenia was found in 76% patients. Bradycardia was found in 41 %. CONCLUSIONS The present study had an objective of studying clinical manifestations and haematological profile associated with dengue fever. A positive Hess test should prompt close observation and early hospital referral, but a negative test does not exclude dengue infection. Bleeding tendencies should be closely watched for. When features of plasma leakage such as pedal oedema, pleural effusion, ascites are present, the patient should be closely watched for and should be immediately managed. The treatment of dengue is mainly supportive. However, appropriate fluid management plays a major role in outcome of the disease. Dengue sero-surveillance studies may give some idea about advent, intensity, transmission season, seasonal incidence, waxing and waning, and impending epidemic of dengue and DHF. A large-scale active longitudinal sero-survey along with the study of vector capacity and vector competence would provide more correct information. A total of 100 patients admitted to our hospital with fever (>38.50 F and Ig

Could peak proteinuria determine whether patient with dengue fever develop dengue hemorrhagic/dengue shock syndrome? - A prospective cohort study

Directory of Open Access Journals (Sweden)

Suhail Sufi M

2011-08-01

Full Text Available Abstract Background Worldwide there is a need to develop simple effective predictors that can distinguish whether a patient will progress from dengue fever (DF to life threatening dengue hemorrhagic (DHF or dengue shock syndrome (DSS. We explored whether proteinuria could be used as such a marker. Methods We included patients admitted to hospital with suspected dengue fever. Starting at enrollment until discharge, each patient's daily spot urine protein creatinine ratio (UPCR was measured. We classified those with confirmed dengue infection as DF or DHF (including DSS based on WHO criteria. Peak and day of onset of proteinuria was compared between both groups. Results Compared to those with DF, patients with DHF had significantly higher median peak proteinuria levels (0.56 versus 0.08 g/day; p Conclusions Peak UPCR could potentially predict DHF in patients with dengue requiring close monitoring and treatment.

Identification of factors for physicians to facilitate early differential diagnosis of scrub typhus, murine typhus, and Q fever from dengue fever in Taiwan.

Science.gov (United States)

Chang, Ko; Lee, Nan-Yao; Ko, Wen-Chien; Tsai, Jih-Jin; Lin, Wei-Ru; Chen, Tun-Chieh; Lu, Po-Liang; Chen, Yen-Hsu

2017-02-01

Dengue fever, rickettsial diseases, and Q fever are acute febrile illnesses with similar manifestations in tropical areas. Early differential diagnosis of scrub typhus, murine typhus, and Q fever from dengue fever may be made by understanding the distinguishing clinical characteristics and the significance of demographic and weather factors. We conducted a retrospective study to identify clinical, demographic, and meteorological characteristics of 454 dengue fever, 178 scrub typhus, 143 Q fever, and 81 murine typhus cases in three Taiwan hospitals. Case numbers of murine typhus and Q fever correlated significantly with temperature and rainfall; the scrub typhus case number was only significantly related with temperature. Neither temperature nor rainfall correlated with the case number of dengue fever. The rarity of dengue fever cases from January to June in Taiwan may be a helpful clue for diagnosis in the area. A male predominance was observed, as the male-to-female rate was 2.1 for murine typhus and 7.4 for Q fever. Multivariate analysis revealed the following six important factors for differentiating the rickettsial diseases and Q fever group from the dengue fever group: fever ≥8 days, alanine aminotransferase > aspartate aminotransferase, platelets >63,000/mL, C-reactive protein >31.9 mg/L, absence of bone pain, and absence of a bleeding syndrome. Understanding the rarity of dengue in the first half of a year in Taiwan and the six differentiating factors may help facilitate the early differential diagnosis of rickettsial diseases and Q fever from dengue fever, permitting early antibiotic treatment. Copyright © 2015. Published by Elsevier B.V.

A model of dengue fever

Directory of Open Access Journals (Sweden)

Boutayeb A

2003-02-01

Full Text Available Abstract Background Dengue is a disease which is now endemic in more than 100 countries of Africa, America, Asia and the Western Pacific. It is transmitted to the man by mosquitoes (Aedes and exists in two forms: Dengue Fever and Dengue Haemorrhagic Fever. The disease can be contracted by one of the four different viruses. Moreover, immunity is acquired only to the serotype contracted and a contact with a second serotype becomes more dangerous. Methods The present paper deals with a succession of two epidemics caused by two different viruses. The dynamics of the disease is studied by a compartmental model involving ordinary differential equations for the human and the mosquito populations. Results Stability of the equilibrium points is given and a simulation is carried out with different values of the parameters. The epidemic dynamics is discussed and illustration is given by figures for different values of the parameters. Conclusion The proposed model allows for better understanding of the disease dynamics. Environment and vaccination strategies are discussed especially in the case of the succession of two epidemics with two different viruses.

Dengue fever treatment with Carica papaya leaves extracts.

Science.gov (United States)

Ahmad, Nisar; Fazal, Hina; Ayaz, Muhammad; Abbasi, Bilal Haider; Mohammad, Ijaz; Fazal, Lubna

2011-08-01

The main objective of the current study is to investigate the potential of Carica papaya leaves extracts against Dengue fever in 45 year old patient bitten by carrier mosquitoes. For the treatment of Dengue fever the extract was prepared in water. 25 mL of aqueous extract of C. papaya leaves was administered to patient infected with Dengue fever twice daily i.e. morning and evening for five consecutive days. Before the extract administration the blood samples from patient were analyzed. Platelets count (PLT), White Blood Cells (WBC) and Neutrophils (NEUT) decreased from 176×10(3)/µL, 8.10×10(3)/µL, 84.0% to 55×10(3)/µL, 3.7×10(3)/µL and 46.0%. Subsequently, the blood samples were rechecked after the administration of leaves extract. It was observed that the PLT count increased from 55×10(3)/µL to 168×10(3)/µL, WBC from 3.7×10(3)/µL to 7.7×10(3)/µL and NEUT from 46.0% to 78.3%. From the patient feelings and blood reports it showed that Carica papaya leaves aqueous extract exhibited potential activity against Dengue fever. Furthermore, the different parts of this valuable specie can be further used as a strong natural candidate against viral diseases.

Severe neutropenia revealing a rare presentation of dengue fever: a case report.

Science.gov (United States)

Shourick, J; Dinh, A; Matt, M; Salomon, J; Davido, B

2017-08-17

Arboviruses are a common cause of fever in the returned traveler often associated with leucopenia, especially lymphopenia and thrombocytopenia. Transient neutropenia has been described in a few cases of arboviruses. However, prolonged and severe neutropenia (dengue fever, especially in the returned traveler in Europe. A 26-year-old healthy female without any medical past history, flying back from Thailand, presented a transient fever with severe neutropenia (dengue fever. Outcome was favorable without any antimicrobial therapy. Physicians should be wary of possible unusual presentation of dengue fever with prolonged neutropenia. Although such biological sign is more often associated with malaria or severe bacterial infection, it may be a sign of arbovirus.

Dengue as a cause of acute undifferentiated fever in Vietnam

NARCIS (Netherlands)

Phuong, H.L.; de Vries, P.J.; Nga, T.T.T.; Giao, P.T.; Hung, L.Q.; Binh, T.Q.; Nam, N.V.; Nagelkerke, N.; Kager, P.A.

2006-01-01

Background: Dengue is a common cause of fever in the tropics but its contribution to the total burden of febrile illnesses that is presented to primary health facilities in endemic regions such as Vietnam, is largely unknown. We aimed to report the frequency of dengue as a cause of fever in Binh

Dengue as a cause of acute undifferentiated fever in Vietnam

NARCIS (Netherlands)

Phuong, Hoang Lan; de Vries, Peter J.; Nga, Tran T. T.; Giao, Phan T.; Hung, Le Q.; Binh, Tran Q.; Nam, Nguyen V.; Nagelkerke, Nico; Kager, Piet A.

2006-01-01

BACKGROUND: Dengue is a common cause of fever in the tropics but its contribution to the total burden of febrile illnesses that is presented to primary health facilities in endemic regions such as Vietnam, is largely unknown. We aimed to report the frequency of dengue as a cause of fever in Binh

Dengue Fever in the United States

Centers for Disease Control (CDC) Podcasts

Dr. Amesh Adalja, an associate at the Center for Biosecurity and clinical assistant professor at the University of Pittsburgh School, of Medicine, discusses dengue fever outbreaks in the United States.

Dengue viral infections

Directory of Open Access Journals (Sweden)

Gurugama Padmalal

2010-01-01

Full Text Available Dengue viral infections are one of the most important mosquito-borne diseases in the world. Presently dengue is endemic in 112 countries in the world. It has been estimated that almost 100 million cases of dengue fever and half a million cases of dengue hemorrhagic fever (DHF occur worldwide. An increasing proportion of DHF is in children less than 15 years of age, especially in South East and South Asia. The unique structure of the dengue virus and the pathophysiologic responses of the host, different serotypes, and favorable conditions for vector breeding have led to the virulence and spread of the infections. The manifestations of dengue infections are protean from being asymptomatic to undifferentiated fever, severe dengue infections, and unusual complications. Early recognition and prompt initiation of appropriate supportive treatment are often delayed resulting in unnecessarily high morbidity and mortality. Attempts are underway for the development of a vaccine for preventing the burden of this neglected disease. This review outlines the epidemiology, clinical features, pathophysiologic mechanisms, management, and control of dengue infections.

Epidemiological, clinical and climatic characteristics of dengue fever in Kaohsiung City, Taiwan with implication for prevention and control.

Science.gov (United States)

Chang, Chiu-Jung; Chen, Colin S; Tien, Chien-Jung; Lu, Mei-Rou

2018-01-01

The early identification of dengue infection is essential for timely and effective quarantine and vector control measures for preventing outbreaks of the disease. Kaohsiung City is responsible for most of the dengue cases in Taiwan. Thus, this study aims to identify major factors involved in the prevalence of dengue fever by analyzing the epidemiological and clinical characteristics, and to establish associations between weather parameters and dengue occurrence in this City. A retrospective study was conducted with 3,322 confirmed dengue cases. Appropriate statistical methods were used to compare differences and correlations between dengue occurrence and demographic, clinical and weather parameters. The outbreak of dengue fever was found to be initiated by imported cases of dengue viruses from other endemic countries. Most of the confirmed cases were not reported to the health authority during the first visit to a doctor, and it took a median of 5 days after the appearance of the first syndromes for medical personnel to report suspected dengue cases. Accordingly, Aedes mosquitoes would have enough time to be infected and transmit the dengue virus. The diagnosis and notification criteria should not only include common symptoms of fever, myalgia, headache, skin rash and arthralgia, but should also be adjusted to include the most frequent symptoms of loss of appetite and feeling thirsty to shorten the notification time. Significantly positive correlations were found between the number of confirmed cases and weather parameters (i.e., temperature, rainfall and relative humidity) at a time lag of 1 month and 2 months. The predictive models for dengue occurrence using these three parameters at a 2-month lag time were established. The surveillance of imported cases, adjustment of notification criteria and application of climatic predictive models would be helpful in strengthening the dengue early warning surveillance system.

Time-specific ecological niche modeling predicts spatial dynamics of vector insects and human dengue cases.

Science.gov (United States)

Peterson, A Townsend; Martínez-Campos, Carmen; Nakazawa, Yoshinori; Martínez-Meyer, Enrique

2005-09-01

Numerous human diseases-malaria, dengue, yellow fever and leishmaniasis, to name a few-are transmitted by insect vectors with brief life cycles and biting activity that varies in both space and time. Although the general geographic distributions of these epidemiologically important species are known, the spatiotemporal variation in their emergence and activity remains poorly understood. We used ecological niche modeling via a genetic algorithm to produce time-specific predictive models of monthly distributions of Aedes aegypti in Mexico in 1995. Significant predictions of monthly mosquito activity and distributions indicate that predicting spatiotemporal dynamics of disease vector species is feasible; significant coincidence with human cases of dengue indicate that these dynamics probably translate directly into transmission of dengue virus to humans. This approach provides new potential for optimizing use of resources for disease prevention and remediation via automated forecasting of disease transmission risk.

The dengue vaccine pipeline: Implications for the future of dengue control

OpenAIRE

Schwartz, Lauren M.; Halloran, M. Elizabeth; Durbin, Anna P.; Longini Jr., Ira M.

2015-01-01

Dengue has become the most rapidly expanding mosquito-borne infectious disease on the planet, surpassing malaria and infecting at least 390 million people per year. There is no effective treatment for dengue illness other than supportive care, especially for severe cases. Symptoms can be mild or life-threatening as in dengue hemorrhagic fever and dengue shock syndrome. Vector control has been only partially successful in decreasing dengue transmission. The potential use of safe and effective ...

Advances in the development of vaccines for dengue fever

Directory of Open Access Journals (Sweden)

Simmons M

2012-05-01

Full Text Available Monika Simmons1, Nimfa Teneza-Mora1, Robert Putnak21Viral and Rickettsial Diseases Department, Naval Medical Research Center, 2Division of Viral Diseases, Walter Reed Army Institute of Research, Silver Spring, MD, USAAbstract: Dengue fever is caused by the mosquito-borne dengue virus (DENV serotypes 1–4, and is the most common arboviral infection of humans in subtropical and tropical regions of the world. There are currently no prophylaxis or treatment options in the form of vaccines or antivirals, leaving vector control the only method of prevention. A particular challenge with DENV is that a successful vaccine has to be effective against all four serotypes without predisposing for antibody-mediated enhanced disease. In this review, we discuss the current lead vaccine candidates in clinical trials, as well as some second-generation vaccine candidates undergoing preclinical evaluation. In addition, we discuss DENV epidemiology, clinical disease and strategies used for Flavivirus antivirals in the past, the development of new DENV therapeutics, and their potential usefulness for prophylaxis and treatment.Keywords: tetravalent dengue vaccine, live attenuated vaccine, purified inactivated vaccine, DNA vaccine, antibody-dependent enhancement, antivirals

Modeled Forecasts of Dengue Fever in San Juan, PR Using NASA Satellite Enhanced Weather Forecasts

Science.gov (United States)

Morin, Cory; Quattrochi, Dale; Zavodsky, Bradley; Case, Jonathan

2015-01-01

Dengue virus is transmitted between humans and mosquitoes of the genus Aedes and causes approximately 96 million cases of disease (dengue fever) each year (Bhatet al. 2013). Symptoms of dengue fever include fever, headache, nausea, vomiting, and eye, muscle and joint pain (CDC). More sever manifestations such as abdominal pain, bleeding from nose and gums, vomiting of blood, and clammy skin occur in rare cases of dengue hemorrhagic fever (CDC). Dengue fever occurs throughout tropical and sub-tropical regions worldwide, however, the geographical range and size of epidemics is increasing. Weather and climate are drivers of dengue virus transmission dynamics (Morin et al. 2013) by affecting mosquito proliferation and the virus extrinsic incubation period (i.e. required time for the virus to replicate and disseminate within the mosquito before it can retransmit the virus).

Nation-wide, web-based, geographic information system for the integrated surveillance and control of dengue fever in Mexico.

Science.gov (United States)

Hernández-Ávila, Juan Eugenio; Rodríguez, Mario-Henry; Santos-Luna, René; Sánchez-Castañeda, Veronica; Román-Pérez, Susana; Ríos-Salgado, Víctor Hugo; Salas-Sarmiento, Jesús Alberto

2013-01-01

Dengue fever incidence and its geographical distribution are increasing throughout the world. Quality and timely information is essential for its prevention and control. A web based, geographically enabled, dengue integral surveillance system (Dengue-GIS) was developed for the nation-wide collection, integration, analysis and reporting of geo-referenced epidemiologic, entomologic, and control interventions data. Consensus in the design and practical operation of the system was a key factor for its acceptance. Working with information systems already implemented as a starting point facilitated its acceptance by officials and operative personnel. Dengue-GIS provides the geographical detail needed to plan, asses and evaluate the impact of control activities. The system is beginning to be adopted as a knowledge base by vector control programs. It is used to generate evidence on impact and cost-effectiveness of control activities, promoting the use of information for decision making at all levels of the vector control program. Dengue-GIS has also been used as a hypothesis generator for the academic community. This GIS-based model system for dengue surveillance and the experience gathered during its development and implementation could be useful in other dengue endemic countries and extended to other infectious or chronic diseases.

Association of Mean Platelet Volume with Severity, Serology & Treatment Outcome in Dengue Fever: Prognostic Utility.

Science.gov (United States)

Sharma, Kritika; Yadav, Ajay

2015-11-01

Dengue is the most rapidly spreading mosquito-borne viral disease in the world. Dengue fever (DF) with its severe manifestations such as dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS) has emerged as a major public health problem of international concern. Thrombocytopenia and bleeding are common complications of dengue fever, hence besides platelet counts, there is a need to assess the role of mean platelet volume. Studying association of mean platelet volume (MPV) with severity, serology & treatment outcome to assess its prognostic utility, which can be of great help in limiting morbidity & mortality associated with dengue fever. The present study was conducted in Central Pathology Lab of SMS Medical College & Hospital, Jaipur, Rajasthan from the period of March 2013 till October 2013. Blood samples were collected from 200 patients with NS 1 Antigen positivity experiencing febrile illness, clinically consistent with dengue infection. Evaluation of platelet counts, MPV, IgM and IgG antibodies was done in all these cases. Categorical data were presented as numbers (percent) and were compared among groups using Chi-square test. Groups compared for demographic data were presented as mean and standard deviation and were compared using student t-test, ANOVA and Post-Hoc Test, Tukey Test using SPSS, version 20 for Windows. A total of 200 Dengue fever cases were studied. Out of which, 68% cases were of DF, 23% DHF & 9% DSS i.e. classical dengue fever was most common presentation. Maximum (44%) cases were in age group of 15-24 years. Fever was the presenting complaint in all cases (100%). 98% cases of dengue had thrombocytopenia. MPV showed no significant correlation with severity, serology & treatment outcome, thus excluding its role in dengue cases. Mean platelet volume is not important as prognostic parameter in dengue fever.

Dengue and Chikungunya Vector Control Pocket Guide

Science.gov (United States)

This technical guide consolidates information and procedures for surveillance and control of mosquitoes that transmit dengue and chikungunya viruses. The guide focuses on mosquitoes that transmit dengue but also makes reference to chikungunya and yellow fever because the pathogens that cause these ...

Frequency, Pattern and Management of Acute Abdomen in Dengue Fever in Karachi, Pakistan

OpenAIRE

Muhammad Shamim

2010-01-01

This study aimed to determine the frequency, pattern and management of acute abdomen in patients with dengue fever. Methods: This descriptive case series is a prospective analysis of acute abdomen in dengue fever that was performed at three secondary care hospitals in Karachi, Pakistan from June 1, 2005 to December 31, 2008. The inclusion criterion was all patients with confirmed diagnosis of dengue fever. Patients with incomplete laboratory, ultrasound or histopathology data were excluded...

Findings at brain MRI in children with dengue fever and neurological symptoms

International Nuclear Information System (INIS)

Rastogi, Ruchi; Garg, Bhavya

2016-01-01

Dengue is a flavivirus of the genus arbovirus with four serotypes, from DEN 1 to DEN 4. There has been an increase in incidence of dengue infection in children in the tropics and subtropics. Dengue has a variable clinical presentation, with many patients being asymptomatic. Its clinical manifestations in children vary from fever and arthralgia to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We describe MRI findings in children with neurological involvement including dengue encephalopathy, acute hypoxic injury and dengue encephalitis. Dengue encephalopathy is usually secondary to multisystem derangement such as shock, hepatitis, coagulopathy and concurrent bacterial infection and is relatively common. Dengue encephalitis from direct neuronal invasion is rare. Nonspecific changes are seen on brain MRI in dengue infection. Clinical and laboratory findings as well as outcome do not necessarily correspond with brain MRI findings. (orig.)

Findings at brain MRI in children with dengue fever and neurological symptoms

Energy Technology Data Exchange (ETDEWEB)

Rastogi, Ruchi; Garg, Bhavya [Indraprastha Apollo Hospitals, Department of Radiodiagnosis, New Delhi (India)

2016-01-15

Dengue is a flavivirus of the genus arbovirus with four serotypes, from DEN 1 to DEN 4. There has been an increase in incidence of dengue infection in children in the tropics and subtropics. Dengue has a variable clinical presentation, with many patients being asymptomatic. Its clinical manifestations in children vary from fever and arthralgia to life-threatening dengue hemorrhagic fever and dengue shock syndrome. We describe MRI findings in children with neurological involvement including dengue encephalopathy, acute hypoxic injury and dengue encephalitis. Dengue encephalopathy is usually secondary to multisystem derangement such as shock, hepatitis, coagulopathy and concurrent bacterial infection and is relatively common. Dengue encephalitis from direct neuronal invasion is rare. Nonspecific changes are seen on brain MRI in dengue infection. Clinical and laboratory findings as well as outcome do not necessarily correspond with brain MRI findings. (orig.)

Environmentally-driven ensemble forecasts of dengue fever

Science.gov (United States)

Yamana, T. K.; Shaman, J. L.

2017-12-01

Dengue fever is a mosquito-borne viral disease prevalent in the tropics and subtropics, with an estimated 2.5 billion people at risk of transmission. In many areas where dengue is found, disease transmission is seasonal but prone to high inter-annual variability with occasional severe epidemics. Predicting and preparing for periods of higher than average transmission remains a significant public health challenge. Recently, we developed a framework for forecasting dengue incidence using an dynamical model of disease transmission coupled with observational data of dengue cases using data-assimilation methods. Here, we investigate the use of environmental data to drive the disease transmission model. We produce retrospective forecasts of the timing and severity of dengue outbreaks, and quantify forecast predictive accuracy.

Ocular manifestations of dengue fever in an East Indian epidemic.

Science.gov (United States)

Kapoor, Harpreet K; Bhai, Saloni; John, Mary; Xavier, Jai

2006-12-01

The incidence and geographic distribution of dengue has increased dramatically in recent years. Previously, ocular findings in dengue fever were considered rare. We report a spectrum of ocular manifestations of this potentially fatal disease and its association with laboratory parameters. 134 patients hospitalized with a diagnosis of dengue fever during an epidemic were included. Systemic and ophthalmic examinations were completed on all patients. The mean age was 31.3 years and 63.4% were males. All patients presented with fever. Six (4.5%) patients had retrobulbar pain and none of the patients presented with any visual complaints. Ocular findings were present in 54 (40.3%) patients. Subconjunctival haemorrhage was the commonest eye finding seen in 50 patients, of whom 84% had characteristic petechial type of haemorrhages. Fundus findings present in 10 (7.5%) patients included dilatation and tortuosity of vessels, superficial retinal haemorrhages, cotton-wool spots, and hard exudates; the macula, however, was spared in all patients. Only 6 of the patients with posterior segment involvement returned for follow-up examination and it was found that retinal changes had resolved without any specific treatment within 2 to 8 weeks time. Of all laboratory parameters evaluated, marked thrombocytopenia (platelet count petechial type, are a common manifestation of dengue infection. Dengue fever patients with marked thrombocytopenia are predisposed to spontaneous ocular haemorrhages.

Dengue fever in pregnancy: a case report

Directory of Open Access Journals (Sweden)

Phupong Vorapong

2001-12-01

Full Text Available Abstract Background Dengue, a mosquito-borne flavivirus infection, is endemic in Southeast Asia. Currently, the incidence has been increasing among adults. Case presentation A 26-year-old Thai woman, G1P0 31 weeks pregnancy, presented with epigastric pain for 1 day. She also had a high-grade fever for 4 days. The physical examination, complete blood counts as well as serology confirmed dengue fever. The patient was under conservative treatment despite severe thrombocytopenia. She was well at the 3rd day of discharge and 1-week follow-up. The pregnancy continued until term without any complication and she delivered vaginally a healthy female baby. Conclusions More cases of dengue infection in pregnancy can be found due to the increasing incidence during adulthood. It should be suspected when a pregnant woman presents with symptoms and signs like in a non-pregnant. Conservative treatment should be conducted unless there are any complications.

Acute Compressive Ulnar Neuropathy in a Patient of Dengue Fever: An Unusual Presentation

Directory of Open Access Journals (Sweden)

Anil K Mehtani

2013-04-01

Full Text Available Introduction: Dengue haemorrhagic fever is known for its haemorrhagic and neurologic complications. Neurologic complications are caused by three mechanism namely neurotropism, systemic complications causing encephalopathy and postinfectious immune-mediated mechanisms. However acute compressive neuropathy due to haemorrhage is not frequent and we could find no literature describing this Case Report: We report a case of acute compressive ulnar neuropathy due to peri neural hematoma, following an attempt at intravenous cannulation in the cubital fossa in a patient of dengue haemorrhagic fever with thrombocytopenia. Immediate fasciotomy and removal of haematoma was performed to relieve the symptoms. Conclusion: Compression neuropathies can be seen in dengue hemorrhagic fever and removal of compressing hematoma relieves symptoms. Keywords: Dengue haemmorrhagic fever; coagulopathy; peri neural haematoma.

SECONDARY BACTERIAL INFECTION IN ADULT PATIENTS WITH PROLONGED AND SEVERE DENGUE FEVER

Directory of Open Access Journals (Sweden)

Anil Kumar

2016-05-01

Full Text Available INTRODUCTION Generally, in dengue shock syndrome antibiotics are not advised. But unrecognised bacterial infection is likely to contribute to morbidity and mortality, probably because of increased vascular permeability. OBJECTIVES To assess the incidence of secondary bacterial infection in adult patients with prolonged and severe dengue fever. METHODS A prospective study was conducted recruiting patients with confirmed acute dengue infection who had prolonged fever (>5 days. Prior to institution of antibiotic therapy, two sets of blood cultures were taken from patients. Demographic, clinical, haematological and biochemical parameters were recorded. Severity of fever & associated symptoms assessed. Ultrasonography done to find out development of ascites and pleural effusions. RESULTS Sixty patients (60.0% males with a mean age of 33.5 years (SD 12.1 were studied. The average duration of fever was 6.9 days (SD 1.6. Fifteen patients (25% had bacterial isolates in their blood cultures; Staphylococcus aureus (n=3, coliforms (n=7, pseudomonas (n=2 and 3 had mixed growths. The culture positive group had severe body aches and joints paint at admission and high grade fever, third space fluid accumulation and significant drop in platelets compared to culture-negative group. CONCLUSIONS A quarter of dengue patients with prolonged fever had a bacterial isolate. Culture-positive patients appeared more ill with body aches and had higher degrees of fever during the course of the illness. Increased vascular permeability may predispose to bacterial seepage into blood. Although white cell count is not helpful in detecting bacteraemia in dengue fever, low platelet count and severe symptoms at presentation may be helpful.

Dengue as a cause of fever during pregnancy: a report of two cases

Directory of Open Access Journals (Sweden)

Ariani Impieri Souza

2016-06-01

Full Text Available Abstract: Dengue infection has not been routinely investigated among pregnant women and parturients with acute febrile syndrome in endemic settings. Here, we report two cases of dengue fever detected at the time of delivery in parturients enrolled in a cohort prospective study conducted in a hospital in Recife, Brazil. The parturients reported fever onset within seven days prior to delivery, and dengue infection was confirmed upon detection of viral ribonucleic acid (RNA by using the reverse transcriptase-polymerase chain reaction. Dengue infection should be considered as a diagnostic possibility in cases of fever during pregnancy and labor, especially in endemic areas.

Frequency, pattern and management of acute abdomen in dengue fever in Karachi, Pakistan.

Science.gov (United States)

Shamim, Muhammad

2010-07-01

This study aimed to determine the frequency, pattern and management of acute abdomen in patients with dengue fever. This descriptive case series is a prospective analysis of acute abdomen in dengue fever that was performed at three secondary care hospitals in Karachi, Pakistan from June 1, 2005 to December 31, 2008. The inclusion criterion was all patients with confirmed diagnosis of dengue fever. Patients with incomplete laboratory, ultrasound or histopathology data were excluded. Among 357 patients with dengue fever, 43 (12.04%) had acute abdomen. There were 15 men and 28 women, with a median age of 29 years. These included 26 cases of acute cholecystitis, 7 cases of acute appendicitis, 7 cases of nonspecific peritonitis, and 3 cases of acute pancreatitis. Dengue hemorrhagic fever/shock syndrome was found in acute pancreatitis, and two of these patients died. Emergency surgery was required in eight patients (5 appendectomy and 3 open cholecystectomy). Substantial transfusion of blood and its components was required in eight patients who underwent emergency surgery. Early diagnosis and prompt conservative management of dengue acute abdomen is necessary to avoid mortality and emergency surgery-related morbidity. However, if needed, surgery can be performed with acceptable morbidity. Copyright © 2010 Asian Surgical Association. Published by Elsevier B.V. All rights reserved.

Value of syndromic surveillance within the Armed Forces for early warning during a dengue fever outbreak in French Guiana in 2006

Directory of Open Access Journals (Sweden)

Jefferson Henry

2008-07-01

Full Text Available Abstract Background A dengue fever outbreak occured in French Guiana in 2006. The objectives were to study the value of a syndromic surveillance system set up within the armed forces, compared to the traditional clinical surveillance system during this outbreak, to highlight issues involved in comparing military and civilian surveillance systems and to discuss the interest of syndromic surveillance for public health response. Methods Military syndromic surveillance allows the surveillance of suspected dengue fever cases among the 3,000 armed forces personnel. Within the same population, clinical surveillance uses several definition criteria for dengue fever cases, depending on the epidemiological situation. Civilian laboratory surveillance allows the surveillance of biologically confirmed cases, within the 200,000 inhabitants. Results It was shown that syndromic surveillance detected the dengue fever outbreak several weeks before clinical surveillance, allowing quick and effective enhancement of vector control within the armed forces. Syndromic surveillance was also found to have detected the outbreak before civilian laboratory surveillance. Conclusion Military syndromic surveillance allowed an early warning for this outbreak to be issued, enabling a quicker public health response by the armed forces. Civilian surveillance system has since introduced syndromic surveillance as part of its surveillance strategy. This should enable quicker public health responses in the future.

Computational Intelligence Method for Early Diagnosis Dengue Haemorrhagic Fever Using Fuzzy on Mobile Device

Directory of Open Access Journals (Sweden)

Salman Afan

2014-03-01

Full Text Available Mortality from Dengue Haemorrhagic Fever (DHF is still increasing in Indonesia particularly in Jakarta. Diagnosis of the dengue shall be made as early as possible so that first aid can be given in expectation of decreasing death risk. The Study will be conducted by developing expert system based on Computational Intelligence Method. On the first year, study will use the Fuzzy Inference System (FIS Method to diagnose Dengue Haemorrhagic Fever particularly in Mobile Device consist of smart phone. Expert system application which particularly using fuzzy system can be applied in mobile device and it is useful to make early diagnosis of Dengue Haemorrhagic Fever that produce outcome faster than laboratory test. The evaluation of this application is conducted by performing accuracy test before and after validation using data of patient who has the Dengue Haemorrhagic Fever. This expert system application is easy, convenient, and practical to use, also capable of making the early diagnosis of Dengue Haemorraghic to avoid mortality in the first stage.

Nation-wide, web-based, geographic information system for the integrated surveillance and control of dengue fever in Mexico.

Directory of Open Access Journals (Sweden)

Juan Eugenio Hernández-Ávila

Full Text Available Dengue fever incidence and its geographical distribution are increasing throughout the world. Quality and timely information is essential for its prevention and control. A web based, geographically enabled, dengue integral surveillance system (Dengue-GIS was developed for the nation-wide collection, integration, analysis and reporting of geo-referenced epidemiologic, entomologic, and control interventions data. Consensus in the design and practical operation of the system was a key factor for its acceptance. Working with information systems already implemented as a starting point facilitated its acceptance by officials and operative personnel. Dengue-GIS provides the geographical detail needed to plan, asses and evaluate the impact of control activities. The system is beginning to be adopted as a knowledge base by vector control programs. It is used to generate evidence on impact and cost-effectiveness of control activities, promoting the use of information for decision making at all levels of the vector control program. Dengue-GIS has also been used as a hypothesis generator for the academic community. This GIS-based model system for dengue surveillance and the experience gathered during its development and implementation could be useful in other dengue endemic countries and extended to other infectious or chronic diseases.

Spatial distribution of the risk of dengue fever in southeast Brazil, 2006-2007

Directory of Open Access Journals (Sweden)

Nucci Luciana B

2011-05-01

Full Text Available Abstract Background Many factors have been associated with circulation of the dengue fever virus and vector, although the dynamics of transmission are not yet fully understood. The aim of this work is to estimate the spatial distribution of the risk of dengue fever in an area of continuous dengue occurrence. Methods This is a spatial population-based case-control study that analyzed 538 cases and 727 controls in one district of the municipality of Campinas, São Paulo, Brazil, from 2006-2007, considering socio-demographic, ecological, case severity, and household infestation variables. Information was collected by in-home interviews and inspection of living conditions in and around the homes studied. Cases were classified as mild or severe according to clinical data, and they were compared with controls through a multinomial logistic model. A generalized additive model was used in order to include space in a non-parametric fashion with cubic smoothing splines. Results Variables associated with increased incidence of all dengue cases in the multiple binomial regression model were: higher larval density (odds ratio (OR = 2.3 (95%CI: 2.0-2.7, reports of mosquito bites during the day (OR = 1.8 (95%CI: 1.4-2.4, the practice of water storage at home (OR = 2.5 (95%CI: 1.4, 4.3, low frequency of garbage collection (OR = 2.6 (95%CI: 1.6-4.5 and lack of basic sanitation (OR = 2.9 (95%CI: 1.8-4.9. Staying at home during the day was protective against the disease (OR = 0.5 (95%CI: 0.3-0.6. When cases were analyzed by categories (mild and severe in the multinomial model, age and number of breeding sites more than 10 were significant only for the occurrence of severe cases (OR = 0.97, (95%CI: 0.96-0.99 and OR = 2.1 (95%CI: 1.2-3.5, respectively. Spatial distribution of risks of mild and severe dengue fever differed from each other in the 2006/2007 epidemic, in the study area. Conclusions Age and presence of more than 10 breeding sites were significant only

Successful allogeneic stem cells transplantation in severe aplastic anaemia complicated by dengue fever

International Nuclear Information System (INIS)

Ullah, K.; Satti, T.M.; Ahmed, P.; Raza, A.; Akhtar, F.M.; Tariq, W.U.Z.

2007-01-01

Aplastic anaemia is characterized by severe compromise of haematopoiesis and hypocellular bone marrow. Haemorrhagic episodes in patients with aplastic anemia occur usually secondary to thrombocytopenia and require frequent support with platelet concentrates and other blood products. Infection with dengue virus (particularly dengue sero type-2 of South Asian genotype) is associated with dengue haemorrhagic fever. Dengue infection further worsens the disease process in patients with aplastic anaemia due to uncontrolled haemorrhagic diathesis and major organ failure, which may prove fatal in these already immunocompromised patients, if not treated in time. Recent epidemics of dengue haemorrhagic fever has not only affected the southern region of our country but also spread to other areas of the country. With this background, we report a case of aplastic anaemia complicated by dengue haemorrhagic fever who achieved successful engraftment after allogeneic stem cell transplantation from sibling brother and is having normal healthy post transplant life. (author)

Nine year trends of dengue virus infection in Mumbai, Western India

OpenAIRE

Shastri, Jayanthi; Williamson, Manita; Vaidya, Nilima; Agrawal, Sachee; Shrivastav, Om

2017-01-01

Introduction: Dengue virus (DENV) causes a wide range of diseases in humans, from acute febrile illness Dengue fever (DF) to life-threatening Dengue hemorrhagic fever (DHF) or Dengue shock syndrome (DSS). Factors believed to be responsible for spread of Dengue virus infection include explosive population growth, unplanned urban overpopulation with inadequate public health systems, poor standing water and vector control, climate changes and increased international recreational, business, milit...

Skin lesions in hospitalized cases of dengue fever

International Nuclear Information System (INIS)

Saleem, K.; Shaikh, I.

2008-01-01

To determine the frequency and types of skin lesions in cases of dengue fever in patients admitted in three hospitals of Karachi. One hundred patients of dengue fever with positive anti-dengue Immunoglobulin M (IgM) serology were included in the study. The admitted patients in PNS Shifa Hospital, Jinnah Postgraduate Medical Centre (JPMC) and Civil Hospital, Karachi were selected for the study. Presenting features were noted. The patients were physically examined for the presence of skin and mucosal lesions and findings were recorded. Total and Differential Leukocyte Count (TLC and DLC), platelet count and Liver Function Tests (LFTs) were done in all the patients. All the patients had low leukocyte and low platelet counts. The common presenting symptoms were high-grade fever with or without rigors, headache, body aches, backache, vomiting, sore throat with cough and generalized weakness (seen in 86% patients). The uncommon presenting features were diarrhea, abdominal pain, bleeding from gums and nosebleeds (seen in 14% patients). Sixty-eight (68%) patients had skin lesions. The most common skin presentation was generalized macular blanchable erythema involving trunk and limbs, seen in 44 (65%) cases. Discrete petechial lesions were seen on various body areas in 24 (35%) cases. Palmer erythema was seen in 20 (30%) patients. Generalized itching was seen in 16 (23%) cases. Isolated itching of palms and soles was seen in 20 (30%) cases. Twenty-eight (28%) patients had deranged LFTs. Out of those, 4 patients had raised serum bilirubin level whereas rest of the 24 had raised ALT. Dengue fever commonly presents with specific skin lesions. The skin lesions can be a clue to the diagnosis in difficult cases. (author)

Skin lesions in hospitalized cases of dengue fever

Energy Technology Data Exchange (ETDEWEB)

Saleem, K; Shaikh, I [Jinnah Postgraduate Medical Hospital, Karachi (Pakistan)

2008-10-15

To determine the frequency and types of skin lesions in cases of dengue fever in patients admitted in three hospitals of Karachi. One hundred patients of dengue fever with positive anti-dengue Immunoglobulin M (IgM) serology were included in the study. The admitted patients in PNS Shifa Hospital, Jinnah Postgraduate Medical Centre (JPMC) and Civil Hospital, Karachi were selected for the study. Presenting features were noted. The patients were physically examined for the presence of skin and mucosal lesions and findings were recorded. Total and Differential Leukocyte Count (TLC and DLC), platelet count and Liver Function Tests (LFTs) were done in all the patients. All the patients had low leukocyte and low platelet counts. The common presenting symptoms were high-grade fever with or without rigors, headache, body aches, backache, vomiting, sore throat with cough and generalized weakness (seen in 86% patients). The uncommon presenting features were diarrhea, abdominal pain, bleeding from gums and nosebleeds (seen in 14% patients). Sixty-eight (68%) patients had skin lesions. The most common skin presentation was generalized macular blanchable erythema involving trunk and limbs, seen in 44 (65%) cases. Discrete petechial lesions were seen on various body areas in 24 (35%) cases. Palmer erythema was seen in 20 (30%) patients. Generalized itching was seen in 16 (23%) cases. Isolated itching of palms and soles was seen in 20 (30%) cases. Twenty-eight (28%) patients had deranged LFTs. Out of those, 4 patients had raised serum bilirubin level whereas rest of the 24 had raised ALT. Dengue fever commonly presents with specific skin lesions. The skin lesions can be a clue to the diagnosis in difficult cases. (author)

Assessing socioeconomic vulnerability to dengue fever in Cali, Colombia: statistical vs expert-based modeling

OpenAIRE

Hagenlocher, Michael; Delmelle, Eric; Casas, Irene; Kienberger, Stefan

2013-01-01

Background As a result of changes in climatic conditions and greater resistance to insecticides, many regions across the globe, including Colombia, have been facing a resurgence of vector-borne diseases, and dengue fever in particular. Timely information on both (1) the spatial distribution of the disease, and (2) prevailing vulnerabilities of the population are needed to adequately plan targeted preventive intervention. We propose a methodology for the spatial assessment of current socioecon...

Assessing Disparities of Dengue Virus Transmission Risk across the US-Mexican Border Using a Climate Driven Vector-Epidemiological Model

Science.gov (United States)

Morin, Cory; Monaghan, Andrew; Quattrochi, Dale; Crosson, William; Hayden, Mary; Ernst, Kacey

2015-01-01

Dengue fever is a mosquito-borne viral disease reemerging throughout much of the tropical Americas. Dengue virus transmission is explicitly influenced by climate and the environment through its primary vector, Aedes aegypti. Temperature regulates Ae. aegypti development, survival, and replication rates as well as the incubation period of the virus within the mosquito. Precipitation provides water for many of the preferred breeding habitats of the mosquito, including buckets, old tires, and other places water can collect. Although transmission regularly occurs along the border region in Mexico, dengue virus transmission in bordering Arizona has not occurred. Using NASA's TRMM (Tropical Rainfall Measuring Mission) satellite for precipitation input and Daymet for temperature and supplemental precipitation input, we modeled dengue transmission along a US-Mexico transect using a dynamic dengue transmission model that includes interacting vector ecology and epidemiological components. Model runs were performed for 5 cities in Sonora, Mexico and southern Arizona. Employing a Monte Carlo approach, we performed ensembles of several thousands of model simulations in order to resolve the model uncertainty arising from using different combinations of parameter values that are not well known. For cities with reported dengue case data, the top model simulations that best reproduced dengue case numbers were retained and their parameter values were extracted for comparison. These parameter values were used to run simulations in areas where dengue virus transmission does not occur or where dengue fever case data was unavailable. Additional model runs were performed to reveal how changes in climate or parameter values could alter transmission risk along the transect. The relative influence of climate variability and model parameters on dengue virus transmission is assessed to help public health workers prepare location specific infection prevention strategies.

Exploratory Analysis of Dengue Fever Niche Variables within the Río Magdalena Watershed

Directory of Open Access Journals (Sweden)

Austin Stanforth

2016-09-01

Full Text Available Previous research on Dengue Fever have involved laboratory tests or study areas with less diverse temperature and elevation ranges than is found in Colombia; therefore, preliminary research was needed to identify location specific attributes of Dengue Fever transmission. Environmental variables derived from the Moderate Resolution Imaging Spectroradiometer (MODIS and Tropical Rainfall Measuring Mission (TRMM satellites were combined with population variables to be statistically compared against reported cases of Dengue Fever in the Río Magdalena watershed, Colombia. Three-factor analysis models were investigated to analyze variable patterns, including a population, population density, and empirical Bayesian estimation model. Results identified varying levels of Dengue Fever transmission risk, and environmental characteristics which support, and advance, the research literature. Multiple temperature metrics, elevation, and vegetation composition were among the more contributory variables found to identify future potential outbreak locations.

Seroprevalence of Dengue Fever in US Army Special Operations Forces: Initial Results and the Way Ahead.

Science.gov (United States)

Caci, Jennifer B; Blaylock, Jason M; De La Barrera, Rafael; Griggs, April N; Lin, Leyi; Jarman, Richard G; Thomas, Stephen J; Lyons, Arthur G

2014-01-01

The endemicity of dengue fever (DF) and, consequently, sequelae of DF are increasing worldwide. The increases are largely a result of widespread international travel and the increased range of the mosquito vectors. US Army Special Operations Command (USASOC) personnel are at an increased risk of exposure to dengue based on their frequent deployments to and presence in dengue endemic areas worldwide. Repeated deployments to different endemic areas can increase the risk for developing the more serious sequelae of dengue: dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Information about the seroprevalence rate of dengue in USASOC personnel, in particular, is lacking and is critical to assessing the risk, tailoring preventive medicine countermeasures, leveraging field diagnostics, and maintaining mission capability. In the first part of a two-part project to assess baseline seroprevalence in USASOC units, a random, unit-stratified sample of 500 anonymous serum specimens from personnel assigned to the highest-risk units in USASOC were screened for dengue using a microneutralization assay. Of the 500 specimens screened, 56 (11.2%) of 500 had neutralizing titers (NT) (MN₅₀≥10) against at least one DENV serotype. Subsequent sample titration resulted in 48 (85.7%) of 56 of the samples with NT (MN₅₀≥10) against at least one dengue serotype for an overall dengue exposure rate of 9.6% (48 of 500). The second part of the ongoing project, started in 2012, was a multicenter, serosurveillance project using predeployment and postdeployment sera collected from USASOC personnel deployed to South and Central America, Africa, and Southeast Asia. Preliminary results show a 13.2% (55 of 414) seropositivity rate. The significance of these findings as they relate to personal risk and operational impact is discussed. 2014.

Spatiotemporal analysis of indigenous and imported dengue fever cases in Guangdong province, China

Directory of Open Access Journals (Sweden)

Li Zhongjie

2012-06-01

Full Text Available Abstract Background Dengue fever has been a major public health concern in China since it re-emerged in Guangdong province in 1978. This study aimed to explore spatiotemporal characteristics of dengue fever cases for both indigenous and imported cases during recent years in Guangdong province, so as to identify high-risk areas of the province and thereby help plan resource allocation for dengue interventions. Methods Notifiable cases of dengue fever were collected from all 123 counties of Guangdong province from 2005 to 2010. Descriptive temporal and spatial analysis were conducted, including plotting of seasonal distribution of cases, and creating choropleth maps of cumulative incidence by county. The space-time scan statistic was used to determine space-time clusters of dengue fever cases at the county level, and a geographical information system was used to visualize the location of the clusters. Analysis were stratified by imported and indigenous origin. Results 1658 dengue fever cases were recorded in Guangdong province during the study period, including 94 imported cases and 1564 indigenous cases. Both imported and indigenous cases occurred more frequently in autumn. The areas affected by the indigenous and imported cases presented a geographically expanding trend over the study period. The results showed that the most likely cluster of imported cases (relative risk = 7.52, p  Conclusions This study demonstrated that the geographic range of imported and indigenous dengue fever cases has expanded over recent years, and cases were significantly clustered in two heavily urbanised areas of Guangdong province. This provides the foundation for further investigation of risk factors and interventions in these high-risk areas.

Bilateral optic neuritis with maculopathy: A rare manifestation of dengue fever

Directory of Open Access Journals (Sweden)

Yang Liang Boo

2017-04-01

Full Text Available Dengue fever is a common mosquito-borne disease, which is endemic in tropical and subtropical countries. Bilateral optic neuropathy is a relatively unusual dengue-related ocular complication. Here, we present a case of bilateral optic neuritis with maculopathy complicating dengue infection.

STUDY OF ULTRASOUND FINDING IN DENGUE FEVER

Directory of Open Access Journals (Sweden)

Sunita Bajaj

2016-10-01

Full Text Available BACKGROUND Dengue fever (DF is a viral haemorrhagic fever causing severe morbidity and mortality in affected patients. The aim of the study is to describe the role of ultrasonography (USG in the assessment of patients with Dengue fever, and its complications and to prove ultrasound is useful in the diagnosis during an epidemic. MATERIALS AND METHODS It is a prospective study was conducted in 2016 comprising of 178 patients who were serologically positive for dengue, radiological investigations were conducted in all cases. RESULTS Out of 178 patients Males (N=117 are more effected subjects in the study. female: Male ratio is 1:2. Hepatomegaly 74.1% which is most common findings in study, 113 (63.4% had GB wall thickening 98 had ascites (55%, 32 had pleural effusion (17.9%. most commonly seen in the age group of 20-39 years. Hepatomegaly was the most common finding noted in 67 patients (37.6%, followed by GB wall thickening in 65 patients (36.1%. Hepatomegaly was more common in 0-19 is 56 patients with 31.4% years age group Ascites in >40 years age group (16.8%. Hepatomegaly was seen in most of the patients whose platelet count was <40,000. (94.7%. GB wall thickening (88.5% common findings seen in patients whose platelet count was <40,000. In patients with platelet count of 40,000-80,000, Ascites is most common finding (87.5%, followed by Splenomegaly (60.7%. In patients whose platelet count was 80,000-150,000, Ascites (50% was more common than Splenomegaly (45.8%. In three patients with platelet count more than 150,000, no sonological abnormality was detected. CONCLUSIONS Ultrasound findings of hepatic changes, GB wall oedema, splenomegaly, ascites and pleural effusion in patients presenting with signs and symptoms of Dengue fever during an epidemic are diagnostic. Contributing in the differential diagnosis with other causes of febrile disease.

A epidemia de dengue/dengue hemorrágico no município do Rio de Janeiro, 2001/2002 The epidemic of dengue and hemorrhagic dengue fever in the city of Rio de Janeiro, 2001/2002

Directory of Open Access Journals (Sweden)

Clarisse Guimarães Casali

2004-08-01

Full Text Available O objetivo deste estudo foi avaliar a ocorrência dos principais sinais e sintomas dos casos de dengue clássico e dengue hemorrágico na epidemia de 2001-2002 do município do Rio de Janeiro. Foram analisados os 155.242 casos notificados ao Sistema de Informações de Agravos de Notificação, desde janeiro/2001, até junho/2002; deste total, excluindo-se os ignorados, 81.327 casos foram classificados como dengue clássico e 958 como dengue hemorrágico, com um total de 54 óbitos. Avaliaram-se as variáveis referentes à sintomatologia da doença. Manifestações gerais como febre, cefaléia, prostração, mialgia, náuseas e dor retro-orbitária tiveram alta incidência tanto no dengue clássico como no dengue hemorrágico. Por outro lado, manifestações hemorrágicas e algumas de maior gravidade como choque, hemorragia digestiva, petéquias, epistaxe, dor abdominal e derrame pleural, estiveram significativamente associadas ao dengue hemorrágico. Além disso, a evolução do quadro clínico para o óbito foi 34,8 vezes maior no dengue hemorrágico que no dengue clássico (OR=34,8; IC 19,7-61,3.The following study was intended to evaluate the occurrence of typical signs and symptoms in the cases of classic dengue and hemorrhagic dengue fever, during the 2001-2002 epidemic in the city of Rio de Janeiro. The authors reviewed 155,242 cases notified to the Information System of Notification Diseases, from January/2001 to June/2002: 81,327 cases were classified as classic dengue and 958 as hemorrhagic dengue fever, with a total of 60 deaths. Common symptoms, such as fever, headache, prostration, myalgia, nausea and retro-orbital pain, had a high incidence in both classic and hemorrhagic dengue fever. On the other hand, hemorrhagic signs and other signs of severe disease, such as shock, gastrointestinal bleeding, petechiae, epistaxis, abdominal pain and pleural effusion, were strongly associated to hemorrhagic dengue fever. Besides, the occurrence

A case of acute liver failure in dengue hemorrhagic fever

Directory of Open Access Journals (Sweden)

Rama Biswas

2013-07-01

Full Text Available Dengue is an arboviral disease endemic in many parts of the world. The clinical presentation of dengue viral infection ranges from asymptomatic illness to fatal dengue shock syndrome. Although, it is known to cause hepatic involvement, it occasionally results in acute hepatic failure. We report a case of dengue hemorrhagic fever presenting with acute liver failure. The case recovered completely after treatment. Ibrahim Med. Coll. J. 2013; 7(2: 41-42

Skin lesions in hospitalized cases of dengue Fever.

Science.gov (United States)

Saleem, Khawer; Shaikh, Irfan

2008-10-01

To determine the frequency and types of skin lesions in cases of dengue fever in patients admitted in three hospitals of Karachi. Case series. Three tertiary care hospitals of Karachi, from November 2006 to February 2007. One hundred patients of dengue fever with positive anti-dengue Immunoglobulin M (IgM) serology were included in the study. The admitted patients in PNS Shifa Hospital, Jinnah Postgraduate Medical Centre (JPMC) and Civil Hospital, Karachi were selected for the study. Presenting features were noted. The patients were physically examined for the presence of skin and mucosal lesions and findings were recorded. Total and Differential Leukocyte Count (TLC and DLC), platelet count and Liver Function Tests (LFTs) were done in all the patients. All the patients had low leukocyte and low platelet counts. The common presenting symptoms were high-grade fever with or without rigors, headache, body aches, backache, vomiting, sore throat with cough and generalized weakness (seen in 86% patients). The uncommon presenting features were diarrhea, abdominal pain, bleeding from gums and nosebleeds (seen in 14% patients). Sixty-eight (68%) patients had skin lesions. The most common skin presentation was generalized macular blanchable erythema involving trunk and limbs, seen in 44 (65%) cases. Discrete petechial lesions were seen on various body areas in 24 (35%) cases. Palmer erythema was seen in 20 (30%) patients. Generalized itching was seen in 16 (23%) cases. Isolated itching of palms and soles was seen in 20 (30%) cases. Twenty-eight (28%) patients had deranged LFTs. Out of those, 4 patients had raised serum bilirubin level whereas rest of the 24 had raised ALT. Dengue fever commonly presents with specific skin lesions. The skin lesions can be a clue to the diagnosis in difficult cases.

Neurological complications of dengue fever: Experience from a tertiary center of north India

Directory of Open Access Journals (Sweden)

Rajesh Verma

2011-01-01

Full Text Available Introduction: Dengue, an acute viral disease transmitted by Aedes mosquitoes, is highly endemic in many tropical and subtropical areas of the world. Neurological complications of dengue infection have been observed more frequently in the recent past and some studies highlighted varied neurological complications arising in the course of dengue illness. In this retrospective study, we report various neurological complications observed during the last 2 years in patients of dengue fever. Materials and Methods: The patients presenting with neurological complications with positive serology (IgM antibody for dengue infection were consecutively recruited from the Department of Neurology/Medicine from a tertiary center of Lucknow, India. These patients were subjected to a detailed clinical evaluation, laboratory assessment including blood count, hematocrit, coagulation parameters, biochemical assays, serology for dengue fever, enzyme-linked immunosorbent assay for human immunodeficiency virus and other relevant investigations. Results: Twenty-six patients with neurological complications associated with confirmed dengue infection were observed during the last 2 years. Eighteen of these patients were male. Of the 26 patients, 10 patients were suffering from brachial neuritis, four patients had encephalopathy, three patients were consistent with the diagnosis of Guillain Barre syndrome, three patients had hypokalemic paralysis associated with dengue fever and two patients had acute viral myositis. Opsoclonus-myoclonus syndrome was diagnosed in two patients, myelitis in one patient and acute disseminated encephalo-myelitis also in one patient. Conclusion: Dengue fever was associated with widespread neurological complications. Brachial neuritis and opsoclonus-myoclonus syndrome were observed for the first time in this study.

Dengue Fever/Dengue Haemorrhagic Fever : Case Management

OpenAIRE

Nimmannitya, Suchitra

1995-01-01

Dengue infections caused by the four antigenically distinct dengue virus serotypes (dengue virus 1, dengue virus 2, dengue virus 3, dengue virus 4) of the family Flavivindae, are the most important arbovirus disease in man, both in terms of morbidity and mortality. The infection is transmitted from man to man by Aedes mosquitoes. Since 1956, dengue virus infection has resulted in more than 3 million hospital admissions and more than 50,000 deaths in Southeast Asia, Western Pacific countries, ...

Clinical predictors of dengue fever co-infected with leptospirosis among patients admitted for dengue fever - a pilot study.

Science.gov (United States)

Suppiah, Jeyanthi; Chan, Shie-Yien; Ng, Min-Wern; Khaw, Yam-Sim; Ching, Siew-Mooi; Mat-Nor, Lailatul Akmar; Ahmad-Najimudin, Naematul Ain; Chee, Hui-Yee

2017-06-28

Dengue and leptospirosis infections are currently two major endemics in Malaysia. Owing to the overlapping clinical symptoms between both the diseases, frequent misdiagnosis and confusion of treatment occurs. As a solution, the present work initiated a pilot study to investigate the incidence related to co-infection of leptospirosis among dengue patients. This enables the identification of more parameters to predict the occurrence of co-infection. Two hundred sixty eight serum specimens collected from patients that were diagnosed for dengue fever were confirmed for dengue virus serotyping by real-time polymerase chain reaction. Clinical, laboratory and demographic data were extracted from the hospital database to identify patients with confirmed leptospirosis infection among the dengue patients. Thus, frequency of co-infection was calculated and association of the dataset with dengue-leptospirosis co-infection was statistically determined. The frequency of dengue co-infection with leptospirosis was 4.1%. Male has higher preponderance of developing the co-infection and end result of shock as clinical symptom is more likely present among co-infected cases. It is also noteworthy that, DENV 1 is the common dengue serotype among all cases identified as dengue-leptospirosis co-infection in this study. The increasing incidence of leptospirosis among dengue infected patients has posed the need to precisely identify the presence of co-infection for the betterment of treatment without mistakenly ruling out either one of them. Thus, anticipating the possible clinical symptoms and laboratory results of dengue-leptospirosis co-infection is essential.

Management experience of surgical complications of dengue fever patients at hameed latif hospital, Lahore

International Nuclear Information System (INIS)

Ahmad, F.

2012-01-01

Objective: This study was designed to determine the frequency, pattern and management of surgical complications among patients with dengue fever. Design: Cross sectional study design was used. Settings: Hameed Latif Hospital, Lahore. Methods: From March - 2009 to December - 2011 total of 875 patients of dengue fever with positive anti-dengue immunoglobulin M (IgM) serology were included in this study. Complete blood count, liver function test, blood urea, serum creatinin, serum amylase were determined in all patients admitted with the diagnosis of dengue fever. All the patients were evaluated for the presence of surgical complications by physical examination and real time ultrasound abdomen. Patient had CT - abdomen and brain where it was required. Patients having surgical complications were managed in dengue ward and ICU with multidisciplinary approach. Data entry and analysis was done by using SPSS 16. Results: Among 875 patients with dengue fever, 491 (43.9%) patients were men and 384 (48.9%) were women with age range (18 - 70) years. Surgical complications were detected in 121 (13.8%) patients: acute cholecystitis in 46 (5.26%); acute pancreatitis in 19 (2.17%); injection abscess in 14 (1.6%); gastrointestinal bleed in 24 (2.74%); forearm compartment syndrome in 3 (0.34%); abdominal compartment syndrome in 2 (0.23%) and acute appendicitis, 4 (0.46%) patients. Cerebral bleed, retroperitoneal hematoma, abdominal wall hematoma and splenic rupture was seen among 3 (0.34%), 2 (0.23%), 3 (0.34%), and 1 (0.11%) patients, respectively. Out of 121 patients surgery was done in 20 (16.5%) patients while rest of 101 (83.5%) patients were managed conservatively. Two patients died. Conclusion: Surgical complications are common and should be suspected in every patient with dengue fever. Majority of surgical manifestations of dengue fever were managed conservatively however surgical intervention was done in certain cases with favorable outcome. (author)

Dengue knowledge in indoor dengue patients from low socioeconomic class; etiology, symptoms, mode of transmission and prevention

International Nuclear Information System (INIS)

Shams, N.; Ahmed, W.; Seetlani, N.K.; Farhat, S.

2018-01-01

Dengue fever has emerged as an emerging public health issue during last decade bearing significant morbidity and economic burden particularly in third world countries. Current study aims to assess various domains of knowledge of indoor dengue patients. Methods: This descriptive cross-sectional study was conducted at Medicine dept. Rawal Institute of Health Sciences Islamabad and BBH Rawalpindi over 6 months. One hundred and twenty-five adult indoor confirmed cases of dengue from lower socioeconomic class were included after ethical approval. The 25-item dengue knowledge questionnaire including aetiology, symptoms, modes of transmission and prevention of dengue was filled. Results: Among 125 cases (77% males and 23% females), mean age was 30+-13 years. Mean knowledge score was 11+-5 points; with excellent knowledge in 6%, good knowledge (22%), moderate knowledge (23%), fair knowledge (34%) and poor knowledge (17%). Mosquito being a vector of dengue was identified by 78%, with peak time in afternoon (48%). Symptoms identified include fever (95%), headache (55%), muscle pain (44%), rash (33%), retro-orbital pain (32%), joint pains (28%) and abdominal pain (18%). Flies and ticks aren't the vectors of dengue according to 61% and 74% respectively, special mosquito is vector (54%), i.e., Aedes Aegypti (18%) that breeds in standing water (53%). Preventive measures identified were netting (56%), insecticide sprays (54%), covering water containers (38%), removing standing water (36%), mosquito repellents (17%), cutting down bushes (22%) and pouring chemicals in standing water (18%). Conclusion: Our patients from lower socioeconomic class, though aware of vector and mode of transmission, have insufficient knowledge of prevention and vector control measures. There is need to strengthen dengue awareness through community based programs, social media, schools and health care centres for high risk people well before the expected epidemic season about mode of transmission

Complementary alternative medicine use among patients with dengue fever in the hospital setting: a cross-sectional study in Malaysia.

Science.gov (United States)

Ching, SiewMooi; Ramachandran, Vasudevan; Gew, Lai Teck; Lim, Sazlyna Mohd Sazlly; Sulaiman, Wan Aliaa Wan; Foo, Yoke Loong; Zakaria, Zainul Amiruddin; Samsudin, Nurul Huda; Lau, Paul Chih Ming Chih; Veettil, Sajesh K; Hoo, Fankee

2016-01-29

In Malaysia, the number of reported cases of dengue fever demonstrates an increasing trend. Since dengue fever has no vaccine or antiviral treatment available, it has become a burden. Complementary and alternative medicine (CAM) has become one of the good alternatives to treat the patients with dengue fever. There is limited study on the use of CAM among patients with dengue fever, particularly in hospital settings. This study aims to determine the prevalence, types, reasons, expenditure, and resource of information on CAM use among patients with dengue fever. This is a descriptive, cross-sectional study of 306 patients with dengue fever, which was carried out at the dengue clinic of three hospitals. Data were analysed using IBM SPSS Statistics version 21.0 and logistic regression analysis was used to determine the factors associated with CAM use. The prevalence of CAM use was 85.3% among patients with dengue fever. The most popular CAMs were isotonic drinks (85.8%), crab soup (46.7%) and papaya leaf extract (22.2%). The most common reason for CAM use was a good impression of CAM from other CAM users (33.3%). The main resource of information on CAM use among patients with dengue fever was family (54.8%). In multiple logistic regression analysis, dengue fever patients with a tertiary level are more likely to use CAM 5.8 (95% confidence interval (CI 1.62-20.45) and 3.8 (95% CI 1.12-12.93) times than secondary level and primary and below respectively. CAM was commonly used by patients with dengue fever. The predictor of CAM use was a higher level of education.

Dengue fever as a cause of hemophagocytic lymphohistiocytosis.

Science.gov (United States)

Hein, Noely; Bergara, Gabriel Heiser; Moura, Nathalie Bianchini Vieira; Cardoso, Débora Morais; Hirose, Maki; Ferronato, Angela Espósito; Pastorino, Antônio Carlos; Lo, Denise Swei; Gilio, Alfredo Elias

2015-01-01

Dengue is endemic in more than 100 countries in Southeast Asia, the Americas, the western Pacific, Africa and the eastern Mediterranean regions. The virus is transmitted by Aedes mosquitoes. Dengue disease is the most prevalent arthropod-borne viral disease in humans and is a global and national public health concern in several countries. A seasonal pattern of dengue disease is consistently observed. The highest incidences usually correspond to the period of highest rainfall and humidity, providing suitable conditions for Aedes aegypti breeding and survival. In Brazil for instance it is from January to June. Dengue may cause marked changes in bone marrow that result in hypocellularity and, consequently, thrombocytopenia and leucopenia, along with an increase in hematocrit, which is secondary to capillary leakage. However, those abnormalities are usually self-limited, and do not warrant further investigations, such as a marrow biopsy or a myelogram. The occurrence of persistent reactive hemophagocytosis is uncommon and usually leads to serious adverse outcomes. The authors report the case of an 8-year old girl complaining of high-grade fever, malaise, headache, abdominal pain and a cutaneous rash. Laboratory examination revealed atypical lymphocytosis on peripheral blood count, hyperbilirrunemia, abnormal liver enzymes and clotting tests. Serology was positive for dengue. Because of the persistence of fever and laboratory examinations were consistent with hemophagocytic lymphohistiocytosis (HLH) a bone marrow aspiration was performed, which confirmed the presence of hemophagocytosis. Hence we report a rare presentation of dengue accompanied by self-limited HLH that hopefully evolve to favorable outcome.

20 Years Spatial-Temporal Analysis of Dengue Fever and Hemorrhagic Fever in Mexico.

Science.gov (United States)

Hernández-Gaytán, Sendy Isarel; Díaz-Vásquez, Francisco Javier; Duran-Arenas, Luis Gerardo; López Cervantes, Malaquías; Rothenberg, Stephen J

2017-10-01

Dengue Fever (DF) is a human vector-borne disease and a major public health problem worldwide. In Mexico, DF and Dengue Hemorrhagic Fever (DHF) cases have increased in recent years. The aim of this study was to identify variations in the spatial distribution of DF and DHF cases over time using space-time statistical analysis and geographic information systems. Official data of DF and DHF cases were obtained in 32 states from 1995-2015. Space-time scan statistics were used to determine the space-time clusters of DF and DHF cases nationwide, and a geographic information system was used to display the location of clusters. A total of 885,748 DF cases was registered of which 13.4% (n = 119,174) correspond to DHF in the 32 states from 1995-2015. The most likely cluster of DF (relative risk = 25.5) contained the states of Jalisco, Colima, and Nayarit, on the Pacific coast in 2009, and the most likely cluster of DHF (relative risk = 8.5) was in the states of Chiapas, Tabasco, Campeche, Oaxaca, Veracruz, Quintana Roo, Yucatán, Puebla, Morelos, and Guerrero principally on the Gulf coast over 2006-2015. The geographic distribution of DF and DHF cases has increased in recent years and cases are significantly clustered in two coastal areas (Pacific and Gulf of Mexico). This provides the basis for further investigation of risk factors as well as interventions in specific areas. Copyright © 2018 IMSS. Published by Elsevier Inc. All rights reserved.

Overview of current situation of dengue and dengue vector control

Science.gov (United States)

Dengue is the most important arbovirus of humans in the world. It is caused by one of four closely related virus serotypes whose primary vector is Aedes aegypti and secondarily by Ae. albopictus. A global dengue pandemic began in Southeast Asia after World War II and has intensified during the las...

Estimation of the Basic Reproductive Ratio for Dengue Fever at the Take-Off Period of Dengue Infection.

Science.gov (United States)

Jafaruddin; Indratno, Sapto W; Nuraini, Nuning; Supriatna, Asep K; Soewono, Edy

2015-01-01

Estimating the basic reproductive ratio ℛ 0 of dengue fever has continued to be an ever-increasing challenge among epidemiologists. In this paper we propose two different constructions to estimate ℛ 0 which is derived from a dynamical system of host-vector dengue transmission model. The construction is based on the original assumption that in the early states of an epidemic the infected human compartment increases exponentially at the same rate as the infected mosquito compartment (previous work). In the first proposed construction, we modify previous works by assuming that the rates of infection for mosquito and human compartments might be different. In the second construction, we add an improvement by including more realistic conditions in which the dynamics of an infected human compartments are intervened by the dynamics of an infected mosquito compartment, and vice versa. We apply our construction to the real dengue epidemic data from SB Hospital, Bandung, Indonesia, during the period of outbreak Nov. 25, 2008-Dec. 2012. We also propose two scenarios to determine the take-off rate of infection at the beginning of a dengue epidemic for construction of the estimates of ℛ 0: scenario I from equation of new cases of dengue with respect to time (daily) and scenario II from equation of new cases of dengue with respect to cumulative number of new cases of dengue. The results show that our first construction of ℛ 0 accommodates the take-off rate differences between mosquitoes and humans. Our second construction of the ℛ 0 estimation takes into account the presence of infective mosquitoes in the early growth rate of infective humans and vice versa. We conclude that the second approach is more realistic, compared with our first approach and the previous work.

Dengue Fever in the United States

Centers for Disease Control (CDC) Podcasts

2012-04-09

Dr. Amesh Adalja, an associate at the Center for Biosecurity and clinical assistant professor at the University of Pittsburgh School, of Medicine, discusses dengue fever outbreaks in the United States.  Created: 4/9/2012 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 4/16/2012.

Early warning signal for dengue outbreaks and identification of high risk areas for dengue fever in Colombia using climate and non-climate datasets.

Science.gov (United States)

Lee, Jung-Seok; Carabali, Mabel; Lim, Jacqueline K; Herrera, Victor M; Park, Il-Yeon; Villar, Luis; Farlow, Andrew

2017-07-10

Dengue has been prevalent in Colombia with high risk of outbreaks in various locations. While the prediction of dengue epidemics will bring significant benefits to the society, accurate forecasts have been a challenge. Given competing health demands in Colombia, it is critical to consider the effective use of the limited healthcare resources by identifying high risk areas for dengue fever. The Climate Risk Factor (CRF) index was constructed based upon temperature, precipitation, and humidity. Considering the conditions necessary for vector survival and transmission behavior, elevation and population density were taken into account. An Early Warning Signal (EWS) model was developed by estimating the elasticity of the climate risk factor function to detect dengue epidemics. The climate risk factor index was further estimated at the smaller geographical unit (5 km by 5 km resolution) to identify populations at high risk. From January 2007 to December 2015, the Early Warning Signal model successfully detected 75% of the total number of outbreaks 1 ~ 5 months ahead of time, 12.5% in the same month, and missed 12.5% of all outbreaks. The climate risk factors showed that populations at high risk are concentrated in the Western part of Colombia where more suitable climate conditions for vector mosquitoes and the high population level were observed compared to the East. This study concludes that it is possible to detect dengue outbreaks ahead of time and identify populations at high risk for various disease prevention activities based upon observed climate and non-climate information. The study outcomes can be used to minimize potential societal losses by prioritizing limited healthcare services and resources, as well as by conducting vector control activities prior to experiencing epidemics.

Dengue viruses – an overview

Directory of Open Access Journals (Sweden)

Anne Tuiskunen Bäck

2013-08-01

Full Text Available Dengue viruses (DENVs cause the most common arthropod-borne viral disease in man with 50–100 million infections per year. Because of the lack of a vaccine and antiviral drugs, the sole measure of control is limiting the Aedes mosquito vectors. DENV infection can be asymptomatic or a self-limited, acute febrile disease ranging in severity. The classical form of dengue fever (DF is characterized by high fever, headache, stomach ache, rash, myalgia, and arthralgia. Severe dengue, dengue hemorrhagic fever (DHF, and dengue shock syndrome (DSS are accompanied by thrombocytopenia, vascular leakage, and hypotension. DSS, which can be fatal, is characterized by systemic shock. Despite intensive research, the underlying mechanisms causing severe dengue is still not well understood partly due to the lack of appropriate animal models of infection and disease. However, even though it is clear that both viral and host factors play important roles in the course of infection, a fundamental knowledge gap still remains to be filled regarding host cell tropism, crucial host immune response mechanisms, and viral markers for virulence.

Bilateral acute visual loss from Rathke's cleft cyst apoplexy in a patient with dengue fever

Directory of Open Access Journals (Sweden)

Ana Cláudia De Franco Suzuki

2014-10-01

Full Text Available Hemorrhagic complications of optic pathway diseases are extremely rare causes of acute visual loss associated with dengue fever. In this paper we report a patient presenting with dengue fever and bilateral acute visual loss caused by chiasmal compression due to Rathke's cleft cyst apoplexy. Considering the importance of early diagnosis and treatment to visual recovery, apoplexy of sellar and suprasellar tumors should be considered in the differential diagnosis of patients with acute visual loss and dengue fever.

Modeling the Effects of Augmentation Strategies on the Control of Dengue Fever With an Impulsive Differential Equation.

Science.gov (United States)

Zhang, Xianghong; Tang, Sanyi; Cheke, Robert A; Zhu, Huaiping

2016-10-01

Dengue fever has rapidly become the world's most common vector-borne viral disease. Use of endosymbiotic Wolbachia is an innovative technology to prevent vector mosquitoes from reproducing and so break the cycle of dengue transmission. However, strategies such as population eradication and replacement will only succeed if appropriate augmentations with Wolbachia-infected mosquitoes that take account of a variety of factors are carried out. Here, we describe the spread of Wolbachia in mosquito populations using an impulsive differential system with four state variables, incorporating the effects of cytoplasmic incompatibility and the augmentation of Wolbachia-infected mosquitoes with different sex ratios. We then evaluated (a) how each parameter value contributes to the success of population replacement; (b) how different release quantities of infected mosquitoes with different sex ratios affect the success of population suppression or replacement; and (c) how the success of these two strategies can be realized to block the transmission of dengue fever. Analysis of the system's stability, bifurcations and sensitivity reveals the existence of forward and backward bifurcations, multiple attractors and the contribution of each parameter to the success of the strategies. The results indicate that the initial density of mosquitoes, the quantities of mosquitoes released in augmentations and their sex ratios have impacts on whether or not the strategies of population suppression or replacement can be achieved. Therefore, successful strategies rely on selecting suitable strains of Wolbachia and carefully designing the mosquito augmentation program.

Clinico-laboratory spectrum of dengue viral infection and risk factors associated with dengue hemorrhagic fever: a retrospective study.

Science.gov (United States)

Mallhi, Tauqeer Hussain; Khan, Amer Hayat; Adnan, Azreen Syazril; Sarriff, Azmi; Khan, Yusra Habib; Jummaat, Fauziah

2015-09-30

The incidence of dengue is rising steadily in Malaysia since the first major outbreak in 1973. Despite aggressive measures taken by the relevant authorities, Malaysia is still facing worsening dengue crisis over the past few years. There is an urgent need to evaluate dengue cases for better understanding of clinic-laboratory spectrum in order to combat this disease. A retrospective analysis of dengue patients admitted to a tertiary care teaching hospital during the period of six years (2008 - 2013) was performed. Patient's demographics, clinical and laboratory findings were recorded via structured data collection form. Patients were categorized into dengue fever (DF) and dengue hemorrhagic fever (DHF). Appropriate statistical methods were used to compare these two groups in order to determine difference in clinico-laboratory characteristics and to identify independent risk factors of DHF. A total 667 dengue patients (30.69 ± 16.13 years; Male: 56.7 %) were reviewed. Typical manifestations of dengue like fever, myalgia, arthralgia, headache, vomiting, abdominal pain and skin rash were observed in more than 40 % patients. DHF was observed in 79 (11.8 %) cases. Skin rash, dehydration, shortness of breath, pleural effusion and thick gall bladder were more significantly (P  40 years (OR: 4.1, P hospitalization (OR: 2.3, P = 0.037) as independent predictors of DHF. Overall mortality was 1.2 % in our study. Current study demonstrated that DF and DHF present significantly different clinico-laboratory profile. Older age, secondary infection, diabetes mellitus, lethargy, thick gallbladder and delayed hospitalization significantly predict DHF. Prior knowledge of expected clinical profile and predictors of DHF/DSS development would provide information to identify individuals at higher risk and on the other hand, give sufficient time to clinicians for reducing dengue related morbidity and mortality.

Larvicidal and repellent effect of some Tribulus terrestris L., (Zygophyllaceae extracts against the dengue fever mosquito, Aedes aegypti (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Tarek M.Y. El-Sheikh

2016-01-01

Full Text Available Aedes aegypti transmits etiologic agents of yellow fever and dengue. Vaccine for dengue virus is not available and vector control is essential to minimize dengue incidence. The larvicidal and repellent effect of the crude ethanol, acetone and petroleum ether extract leaves of Tribulus terrestris, against 3rd instar larvae and adults of mosquito, Ae. aegypti the vector of dengue fever was evaluated. The efficacy of petroleum ether extract seemed to be more effective with LC50 64.6 ppm followed by acetone extract with LC50 173.2 ppm and finally ethanolic extract with LC50 376.4 ppm. Moreover, the acetone and petroleum ether extracts exerted a highly delayed toxic effect on the pupae and adults resulted from treated larvae, where the pupal mortality was 57.1% and 100% at concentrations 400 and 100 ppm, respectively. Also, the petroleum ether and acetone extracts showed reduction effects on adult emergence. The repellent action of the plant extracts tested was varied depending on the solvent used in extraction and the dose of the extract. The most effective plant extract that evoked 100% repellency or biting deterrence was petroleum ether extract at a dose of 1.5 mg/cm2 compared with 100% repellency for commercial formulation, N,N-diethyl-3-methylbenzamide (DEET at the same dose. Hence, these extracts can be used as an effective alternative to the existing synthetic pesticides for the control of Ae. aegypti.

Dengue in travellers: applicability of the 1975-1997 and the 2009 WHO classification system of dengue fever

NARCIS (Netherlands)

Wieten, Rosanne W.; Vlietstra, Wytze; Goorhuis, Abraham; van Vugt, Michèle; Hodiamont, Caspar J.; Leenstra, Tjalling; de Vries, Peter J.; Janssen, Saskia; van Thiel, Pieter P.; Stijnis, Kees; Grobusch, Martin P.

2012-01-01

Objectives The aim of this study was to assess the applicability and benefits of the new WHO dengue fever guidelines in clinical practice, for returning travellers. Methods We compared differences in specificity and sensitivity between the old and the new guidelines for diagnosing dengue and

Therapeutic antibodies as a treatment option for dengue fever.

Science.gov (United States)

Chan, Kuan Rong; Ong, Eugenia Z; Ooi, Eng Eong

2013-11-01

Dengue fever is the most prevalent mosquito-borne viral disease globally with about 100 million cases of acute dengue annually. Severe dengue infection can result in a life-threatening illness. In the absence of either a licensed vaccine or antiviral drug against dengue, therapeutic antibodies that neutralize dengue virus (DENV) may serve as an effective medical countermeasure against severe dengue. However, therapeutic antibodies would need to effectively neutralize all four DENV serotypes. It must not induce antibody-dependent enhancement of DENV infection in monocytes/macrophages through Fc gamma receptor (FcγR)-mediated phagocytosis, which is hypothesized to increase the risk of severe dengue. Here, we review the strategies and technologies that can be adopted to develop antibodies for therapeutic applications. We also discuss the mechanism of antibody neutralization in the cells targeted by DENV that express Fc gamma receptor. These studies have provided significant insight toward the use of therapeutic antibodies as a potentially promising bulwark against dengue.

NNDSS - Table II. Cryptosporidiosis to Dengue Hemorrhagic Fever

Data.gov (United States)

U.S. Department of Health & Human Services — NNDSS - Table II. Cryptosporidiosis to Dengue Hemorrhagic Fever - 2014.In this Table, all conditions with a 5-year average annual national total of more than or...

La epidemiología del dengue y del dengue hemorrágico en Santiago de Cuba, 1997 The epidemiology of dengue and dengue hemorrhagic fever in Santiago de Cuba, 1997

Directory of Open Access Journals (Sweden)

Luis Valdés

1999-07-01

Full Text Available En 1977, Cuba informó de su primera epidemia de dengue, durante la cual se registraron más de 500 000 casos de fiebre del dengue causados por el serotipo 1 del virus. En 1981, se produjo una gran epidemia de dengue hemorrágico causada por el serotipo 2. Esa vez se notificaron 344 203 casos en total, 10 312 casos clínicos de dengue hemorrágico y 158 defunciones, de las cuales 101 correspondieron a niños. Por medio de una búsqueda activa con confirmación de laboratorio, en el municipio de Santiago de Cuba de la provincia del mismo nombre se detectó precozmente en enero de 1997 la reintroducción del dengue, específicamente del virus del tipo 2, genotipo Jamaica. En este trabajo se presentan los aspectos epidemiológicos de mayor interés referentes a esa epidemia. Se notificaron 3 012 casos confirmados por serología, 205 clasificados como fiebre hemorrágica del dengue/síndrome de choque del dengue, de los cuales 12 fallecieron (todos adultos. La infección secundaria por virus del dengue fue uno de los principales factores de riesgo en el desarrollo de dengue hemorrágico y 98% de los casos, así como 92% de los fallecidos, manifestaron una respuesta de tipo secundario. Por primera vez se observó la posibilidad de contraer dengue hemorrágico en personas con una infección secundaria de 16 a 20 años después de la primera infección. Pertenecer a la raza blanca fue otro factor de riesgo de importancia, tal como se había observado desde la epidemia de 1981. En la última epidemia se demostró que la llamada “alerta de fiebre” no es útil para la detección temprana de una epidemia. Las medidas tomadas por las autoridades sanitarias del país evitaron la extensión de la epidemia a otros municipios que estaban infestados por Aedes aegypti.A dengue epidemic that Cuba reported in 1997 registered more than 500 000 cases of dengue fever produced by viral serotype 1. In 1981, there was an epidemic of dengue hemorrhagic fever produced by

Autoimmunity in dengue pathogenesis

Directory of Open Access Journals (Sweden)

Shu-Wen Wan

2013-01-01

Full Text Available Dengue is one of the most important vector-borne viral diseases. With climate change and the convenience of travel, dengue is spreading beyond its usual tropical and subtropical boundaries. Infection with dengue virus (DENV causes diseases ranging widely in severity, from self-limited dengue fever to life-threatening dengue hemorrhagic fever and dengue shock syndrome. Vascular leakage, thrombocytopenia, and hemorrhage are the major clinical manifestations associated with severe DENV infection, yet the mechanisms remain unclear. Besides the direct effects of the virus, immunopathogenesis is also involved in the development of dengue disease. Antibody-dependent enhancement increases the efficiency of virus infection and may suppress type I interferon-mediated antiviral responses. Aberrant activation of T cells and overproduction of soluble factors cause an increase in vascular permeability. DENV-induced autoantibodies against endothelial cells, platelets, and coagulatory molecules lead to their abnormal activation or dysfunction. Molecular mimicry between DENV proteins and host proteins may explain the cross-reactivity of DENV-induced autoantibodies. Although no licensed dengue vaccine is yet available, several vaccine candidates are under development. For the development of a safe and effective dengue vaccine, the immunopathogenic complications of dengue disease need to be considered.

Cardiac tamponade in a patient with severe dengue fever

Directory of Open Access Journals (Sweden)

Ana Isabel Vieira Fernandes

Full Text Available Abstract A 26-year-old postpartum female presented with symptoms characteristic of dengue fever on the 16th day of puerperium. On the third day of the illness, the patient presented a clinical picture consistent with shock. Tests determined primary infection with dengue virus serotype 2. Cardiac tamponade was confirmed by echocardiography. This rare manifestation is described in a patient without any associated comorbidity.

Risk Factors for the Presence of Chikungunya and Dengue Vectors (Aedes aegypti and Aedes albopictus), Their Altitudinal Distribution and Climatic Determinants of Their Abundance in Central Nepal

Science.gov (United States)

Dhimal, Meghnath; Gautam, Ishan; Joshi, Hari Datt; O’Hara, Robert B.; Ahrens, Bodo; Kuch, Ulrich

2015-01-01

Background The presence of the recently introduced primary dengue virus vector mosquito Aedes aegypti in Nepal, in association with the likely indigenous secondary vector Aedes albopictus, raises public health concerns. Chikungunya fever cases have also been reported in Nepal, and the virus causing this disease is also transmitted by these mosquito species. Here we report the results of a study on the risk factors for the presence of chikungunya and dengue virus vectors, their elevational ceiling of distribution, and climatic determinants of their abundance in central Nepal. Methodology/Principal Findings We collected immature stages of mosquitoes during six monthly cross-sectional surveys covering six administrative districts along an altitudinal transect in central Nepal that extended from Birgunj (80 m above sea level [asl]) to Dhunche (highest altitude sampled: 2,100 m asl). The dengue vectors Ae. aegypti and Ae. albopictus were commonly found up to 1,350 m asl in Kathmandu valley and were present but rarely found from 1,750 to 2,100 m asl in Dhunche. The lymphatic filariasis vector Culex quinquefasciatus was commonly found throughout the study transect. Physiographic region, month of collection, collection station and container type were significant predictors of the occurrence and co-occurrence of Ae. aegypti and Ae. albopictus. The climatic variables rainfall, temperature, and relative humidity were significant predictors of chikungunya and dengue virus vectors abundance. Conclusions/Significance We conclude that chikungunya and dengue virus vectors have already established their populations up to the High Mountain region of Nepal and that this may be attributed to the environmental and climate change that has been observed over the decades in Nepal. The rapid expansion of the distribution of these important disease vectors in the High Mountain region, previously considered to be non-endemic for dengue and chikungunya fever, calls for urgent actions to

Application of Gis in Temporal and Spatial Analyses of Dengue Fever Outbreak : Case of Rio de Janeiro, Brazil

OpenAIRE

Achu, Denis

2009-01-01

Since Dengue fever (DF) and its related forms, Dengue Hemorrhagic fever (DHF) and Dengue Shock Syndrome (DSS) have become important health concerns worldwide, it is also imperative to develop methods which will help in the analysis of the incidences. Dengue fever cases are growing in number as it also invades widely, affecting larger number of countries and crossing climatic boundaries. Considering that the disease as of now has neither an effective vaccine nor a cure, monitoring in order to ...

A Study of Clinical Spectrum of Dengue Fever in A Tertiary Care Centre.

Directory of Open Access Journals (Sweden)

Dr. Gargi Pathak

2016-12-01

Full Text Available Introduction: Dengue viruses, of the family Flaviviridae, are the most common cause of arboviral, disease in the world. We report a clinico-epidemiological study of the dengue fever from paediatric department of civil hospital Ahmedabad. This study was designed to document the presenting features, laboratory results and outcome of dengue infection in children. Methodology: A prospective study was carried from October 2014-october 2015 and total of 126 patients were studied from age group between 1 month to 12 years. A detailed history, careful clinical examination and laboratory investigations were done in all the patients. Results and Conclusions: We documented Leucopenia as an early marker than thrombocytopenia and were seen in more numbers (47% in our study which was not found in the previous studies. Most common symptom was fever with body ache (73%. Majority of patients had platelet count between 50000-1 lakh. 55% had tested positive for dengue IgM and 44.4% had tested positive for dengue NS1. Wide variety of complications like hepatitis (20.6%, myocarditis (14.2%, dengue shock (11.1%, encephalitis (4.7%, Dengue haemorrhagic fever (4.7%, ARDS (2.3% were seen, which might indicate a change in serotype and epidemiology of the Dengue. Interestingly Bradycardia was seen in increased frequency subsequent to myocarditis with simultaneously raised CPK-MB levels. There were increased cases of coinfections like malaria, enteric, hepatitis, UTI, not seen previously .Out of 126 patients 6 patients expired.

RNA Interference: A Promising Tool in the Control of Important Vector Born Diseases Zika, Dengue Fever, and Malaria

Directory of Open Access Journals (Sweden)

Jalil Nejati

2017-05-01

Full Text Available Background and Objectives: RNA interference is a process, in which a molecule of double-stranded RNA prevents the expression of a particular gene and leads to its silencing. Application of this technology in the control of disease-carrying insects is rising in agriculture and medical sciences. Also, its application in control of insect-borne diseases could be considered as a new, important, and effective approach. In this article, it was attempted to study the mechanisms of RNA interference, routs of its delivery to insects, as well as its application in genetic control of disease vector insects. Methods: In this study, 71 indexed articles in databases, such as Pubmed, SID, Scopus, Science direct, and Google scholar, were used. Results: dsRNA could be delivered to insect body through three routes of oral, injection, and Impregnation. The mechanism of dsRNA entrance into the cells has considerable effect on the success and applicability of this technique. Identification of host-parasite relationship in the insect body is one of the important applications of RNAi in medical entomology. Conclusion: Although, there is a considerable number of researches on RNAi in the agricultural pests field, studies on insect vectors of human diseases have been mostly in-vivo. However, application of RNAi is suggested as a new, safe and applicable approach, alone or along with other methods. Certainly, further researches in this field can pave the way for enforcement measures in the control of disease vectors, especially Zika, dengue fever, and malaria in the not so distant future.

Potential Risk Areas of Aedes albopictus in South-Eastern Iran: A Vector of Dengue Fever, Zika, and Chikungunya

Directory of Open Access Journals (Sweden)

Jalil Nejati

2017-09-01

Full Text Available The possibility of the rapid and global spread of Zika, chikungunya, yellow fever, and dengue fever by Aedes albopictus is well documented and may be facilitated by changes in climate. To avert and manage health risks, climatic and topographic information can be used to model and forecast which areas may be most prone to the establishment of Ae. albopictus. We aimed to weigh and prioritize the predictive value of various meteorological and climatic variables on distributions of Ae. albopictus in south-eastern Iran using the Analytical Hierarchy Process. Out of eight factors used to predict the presence of Ae. albopictus, the highest weighted were land use, followed by temperature, altitude, and precipitation. The inconsistency of this analysis was 0.03 with no missing judgments. The areas predicted to be most at risk of Ae. albopictus-borne diseases were mapped using Geographic Information Systems and remote sensing data. Five-year (2011–2015 meteorological data was collected from 11 meteorological stations and other data was acquired from Landsat and Terra satellite images. Southernmost regions were at greatest risk of Ae. albopictus colonization as well as more urban sites connected by provincial roads. This is the first study in Iran to determine the regional probability of Ae. albopictus establishment. Monitoring and collection of Ae. albopictus from the environment confirmed our projections, though on-going field work is necessary to track the spread of this vector of life-threatening disease.

Dengue fever with hepatitis E and hepatitis A infection.

Science.gov (United States)

Yakoob, Javed; Jafri, Wasim; Siddiqui, Shaheer; Riaz, Mehmood

2009-03-01

Infection with dengue viruses produces a spectrum of clinical illness ranging from a nonspecific viral syndrome to severe and fatal haemorrhagic disease. Important risk factors include the strain and serotype of the infecting virus, as well as the age, immune status, and genetic predisposition of the patient. The teaching point in this case study was Dengue fever which occurred concomitantly with Hepatitis A and Hepatitis E virus infection.

IL-10 and socs3 Are Predictive Biomarkers of Dengue Hemorrhagic Fever

Directory of Open Access Journals (Sweden)

Lilian Karem Flores-Mendoza

2017-01-01

Full Text Available Background. Cytokines play important roles in the physiopathology of dengue infection; therefore, the suppressors of cytokine signaling (socs that control the type and timing of cytokine functions could be involved in the origin of immune alterations in dengue. Objective. To explore the association of cytokine and socs levels with disease severity in dengue patients. Methods. Blood samples of 48 patients with confirmed dengue infection were analyzed. Amounts of interleukins IL-2, IL-4, IL-6, and IL-10, interferon- (IFN- γ, and tumor necrosis factor- (TNF- α were quantified by flow cytometry, and the relative expression of socs1 and socs3 mRNA was quantified by real-time RT-PCR. Results. Increased levels of IL-10 and socs3 and lower expression of socs1 were found in patients with dengue hemorrhagic fever (DHF with respect to those with dengue fever (DF (p199.8-fold, socs1 (134 pg/ml have the highest sensitivity and specificity to discriminate between DF and DHF. Conclusion. Simultaneous changes in IL-10 and socs1/socs3 could be used as prognostic biomarkers of dengue severity.

Superior infectivity for mosquito vectors contributes to competitive displacement among strains of dengue virus

Directory of Open Access Journals (Sweden)

Schirtzinger Erin E

2008-02-01

Full Text Available Abstract Background Competitive displacement of a weakly virulent pathogen strain by a more virulent strain is one route to disease emergence. However the mechanisms by which pathogens compete for access to hosts are poorly understood. Among vector-borne pathogens, variation in the ability to infect vectors may effect displacement. The current study focused on competitive displacement in dengue virus serotype 3 (DENV3, a mosquito-borne pathogen of humans. In Sri Lanka in the 1980's, a native DENV3 strain associated with relatively mild dengue disease was displaced by an invasive DENV3 strain associated with the most severe disease manifestations, dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS, resulting in an outbreak of DHF/DSS. Here we tested the hypothesis that differences between the invasive and native strain in their infectivity for Aedes aegypti mosquitoes, the primary vector of DENV, contributed to the competitive success of the invasive strain Results To be transmitted by a mosquito, DENV must infect and replicate in the midgut, disseminate into the hemocoel, infect the salivary glands, and be released into the saliva. The ability of the native and invasive DENV3 strains to complete the first three steps of this process in Aedes aegypti mosquitoes was measured in vivo. The invasive strain infected a similar proportion of mosquitoes as the native strain but replicated to significantly higher titers in the midgut and disseminated with significantly greater efficiency than the native strain. In contrast, the native and invasive strain showed no significant difference in replication in cultured mosquito, monkey or human cells. Conclusion The invasive DENV3 strain infects and disseminates in Ae. aegypti more efficiently than the displaced native DENV3 strain, suggesting that the invasive strain is transmitted more efficiently. Replication in cultured cells did not adequately characterize the known phenotypic differences between

Dengue fever | Tavodova | South Sudan Medical Journal

African Journals Online (AJOL)

South Sudan Medical Journal. Journal Home · ABOUT THIS JOURNAL · Advanced Search · Current Issue · Archives · Journal Home > Vol 5, No 1 (2012) >. Log in or Register to get access to full text downloads. Username, Password, Remember me, or Register. Dengue fever. Milada Tavodova. Abstract. No Abstract ...

CLINICAL AND HEMATOLOGICAL PROFILE OF PATIENTS WITH DENGUE FEVER AT A TERTIARY CARE HOSPITAL – AN OBSERVATIONAL STUDY

Directory of Open Access Journals (Sweden)

Vishal Vishnu Tewari

2018-03-01

Full Text Available Abstract Background: Dengue is a major health issue with seasonal rise in dengue fever cases imposing an additional burden on hospitals, necessitating bolstering of services in the emergency department, laboratory with creation of additional dengue fever wards. Objectives: To study the clinical and hematological profile of dengue fever cases presenting to a hospital. Methods: Patients with fever and other signs of dengue with either positive NS1 antigen test or IgM or IgG antibody were included. Age, gender, clinical presentation, platelet count and hematocrit were noted and patients classified as dengue fever (DF, dengue hemorrhagic fever (DHF or dengue shock syndrome (DSS. Duration of hospitalization, bleeding manifestations, requirement for platelet component support and mortality were recorded. Results: There were 443 adults and 57 children between 6 months to 77 year age. NS1 was positive in 115 patients (23%. Fever (99.8% and severe bodyache (97.4% were the commonest presentation. DF was seen in 484 (96.8 %, DHF in 10 (2% and DSS in 6 cases (1.2%. OPD treatment was needed in 412 (82% and hospitalization in 88 (18%. Intravenous fluid resuscitation was needed in 16 (3.2% patients. Thrombocytopenia was seen in 335 (67% patients at presentation. Platelet transfusion was needed in 46 (9.2%. PRC transfusion was given in 3 patients with DF and 10 of DHF. Death occurred in 03 DSS and 2 DHF patients. Conclusions: Majority of DF cases can be managed on OPD basis. DHF and DSS carry high mortality. Hospitals can analyze annual data for resource allocation for capacity expansion.

Individual and Interactive Effects of Socio-Ecological Factors on Dengue Fever at Fine Spatial Scale: A Geographical Detector-Based Analysis.

Science.gov (United States)

Cao, Zheng; Liu, Tao; Li, Xing; Wang, Jin; Lin, Hualiang; Chen, Lingling; Wu, Zhifeng; Ma, Wenjun

2017-07-17

Background : Large spatial heterogeneity was observed in the dengue fever outbreak in Guangzhou in 2014, however, the underlying reasons remain unknown. We examined whether socio-ecological factors affected the spatial distribution and their interactive effects. Methods : Moran's I was applied to first examine the spatial cluster of dengue fever in Guangzhou. Nine socio-ecological factors were chosen to represent the urbanization level, economy, accessibility, environment, and the weather of the 167 townships/streets in Guangzhou, and then the geographical detector was applied to analyze the individual and interactive effects of these factors on the dengue outbreak. Results : Four clusters of dengue fever were identified in Guangzhou in 2014, including one hot spot in the central area of Guangzhou and three cold spots in the suburban districts. For individual effects, the temperature ( q = 0.33) was the dominant factor of dengue fever, followed by precipitation ( q = 0.24), road density ( q = 0.24), and water body area ( q = 0.23). For the interactive effects, the combination of high precipitation, high temperature, and high road density might result in increased dengue fever incidence. Moreover, urban villages might be the dengue fever hot spots. Conclusions : Our study suggests that some socio-ecological factors might either separately or jointly influence the spatial distribution of dengue fever in Guangzhou.

People's knowledge and practice about dengue, its vectors, and control means in Brasilia (DF), Brazil: its relevance with entomological factors.

Science.gov (United States)

Dégallier, N; Vilarinhos, P T; de Carvalho, M S; Knox, M B; Caetano, J

2000-06-01

In South America, the epidemiology and ecology of dengue fever are strongly associated with human habits because the vector Aedes aegypti is strictly urban. Thus, the evaluation of people's knowledge and practice (PKP) is of great importance to improve integrated control measures. A PKP evaluation has been done in a suburb of Brasilia. Thirty questions were submitted to 130 habitants about income level, education, sources of information, specific knowledge about dengue, vector biology, and control measures applied. Other questions were about the responsibility of dengue control and the opportunity of applying a fine to people who would not cooperate with the control measures. Level of PKP was fairly high, either for housekeepers, workers, or students. The mosquito bite was cited as source of infection by 60.8% of interviewed people but 22.3% had no knowledge about this topic. The most cited symptoms in association with dengue were fever (73.1%), headache (66.2%), and rash (35.4%). Knowledge about mosquito biology and control was also fairly accurate, as demonstrated by 96.9% of answers. Elimination of water containers was the most efficient means according to 73% of people. Such action should be done mainly by the citizen (75.3% of answers). Despite the good PKP, correlations existed only between the PKP about vector biology and presence of potential breeding containers in March, and between the PKP about the disease and potential breeding containers in April. In conclusion, global educational campaigns may have a real impact on the PKP but this did not result in effective control of the mosquito breeding containers by the people.

Socio-demographic determinants of dengue infection during an ...

African Journals Online (AJOL)

Dell

4Southern African Centre for Infectious Disease Surveillance, Africa Centre of Excellence for Infectious Diseases of. Humans and ..... Erlanger, T.E., Keiser, J. & Utzinger, J. (2008) Effect of dengue vector control interventions on ... Dengue fever among hospitalized febrile patients in northern Tanzania. American Journal of.

Estratificación de una ciudad hiperendémica en dengue hemorrágico Stratification of a city with hyperendemic dengue hemorrhagic fever

Directory of Open Access Journals (Sweden)

Roberto Barrera

2000-10-01

Full Text Available La gran heterogeneidad ambiental de viviendas y barrios en los centros urbanos donde se cría Aedes aegypti, principal vector del dengue, junto con la escasez de recursos y de personal entrenado en el control de mosquitos constituyen retos para cualquier iniciativa destinada a controlar el dengue hemorrágico (DH. Una adecuada vigilancia epidemiológica puede servir de base para comenzar a estratificar los centros urbanos e identificar las zonas críticas donde deben concentrarse las tareas de control. En este estudio, se estratificó una ciudad hiperendémica en dengue hemorrágico (Maracay, Venezuela con la ayuda de un sistema de información geográfica (SIG y el análisis de la persistencia, la incidencia y la prevalencia del dengue mediante diagnósticos clínicos registrados de 1993 a 1998. Maracay tiene cerca de un millón de habitantes que viven en unos 349 barrios de 6 poblaciones que integran el Área Metropolitana, donde se notificaron 10 576 casos de dengue, 2 593 casos de DH y 8 defunciones. La incidencia de DH mostró una relación directa con la incidencia del dengue, el número de habitantes y la densidad poblacional. El patrón espacial de la incidencia del dengue fue estable durante los años estudiados y se encontraron relaciones positivas y significativas de la incidencia del dengue por barrio entre pares de años. La persistencia del dengue se relacionó directamente con la incidencia mensual por barrio. Estos patrones espaciales facilitaron la estratificación de la ciudad en tres estratos: 68 barrios sin dengue aparente, 226 barrios con baja persistencia y prevalencia, y 55 barrios con alta persistencia y prevalencia. Se recomienda otorgar alta prioridad de control a estos 55 barrios que ocupan 35% del área urbana y presentaron 70% de todos los casos de dengue.Any effort to control dengue hemorrhagic fever (DHF faces a number of challenges. Among these are the great environmental heterogeneity of homes and neighborhoods

Dengue hemorrhagic fever complicated with acute liver failure: a case report.

Science.gov (United States)

Dalugama, Chamara; Gawarammana, Indika Bandara

2017-12-08

Dengue is a common arboviral infection with a clinically diverse spectrum of presentations. Although hepatic dysfunction is commonly identified in patients will dengue illness, acute liver failure is rare. The etiopathogenesis of hepatic dysfunction is multifactorial and related to direct viral invasion of hepatocytes, immunological factors and hypoxia particularly in cases of shock in dengue hemorrhagic fever. Ideal management of dengue-related hepatic dysfunction and acute liver failure is still debated. We report a 53-year-old Sri Lankan Sinhalese male with serologically confirmed dengue fever presenting with evidence of plasma leakage developing acute liver failure evidenced by deranged liver functions, coagulopathy and altered sensorium. In addition to the 'standard care', the patient was managed with intravenous N-acetyl cysteine and blood transfusions even in the absence of bleeding or dropping packed cell volume (PCV), targeting a higher PCV in anticipation of better oxygenation at tissue level. He made a full recovery with no sequential infections. N-acetyl cysteine and packed cell transfusion aiming at a higher PCV to maintain adequate tissue perfusion during shock may be beneficial in acute liver failure due to dengue virus. Large randomized trials should be carried out to establish the efficacy of these treatment strategies to support these observations and change the current practice.

Dengue vector dynamics (Aedes aegypti influenced by climate and social factors in Ecuador: implications for targeted control.

Directory of Open Access Journals (Sweden)

Anna M Stewart Ibarra

Full Text Available BACKGROUND: Dengue fever, a mosquito-borne viral disease, is now the fastest spreading tropical disease globally. Previous studies indicate that climate and human behavior interact to influence dengue virus and vector (Aedes aegypti population dynamics; however, the relative effects of these variables depends on local ecology and social context. We investigated the roles of climate and socio-ecological factors on Ae. aegypti population dynamics in Machala, a city in southern coastal Ecuador where dengue is hyper-endemic. METHODS/PRINCIPAL FINDINGS: We studied two proximate urban localities where we monitored weekly Ae. aegypti oviposition activity (Nov. 2010-June 2011, conducted seasonal pupal surveys, and surveyed household to identify dengue risk factors. The results of this study provide evidence that Ae. aegypti population dynamics are influenced by social risk factors that vary by season and lagged climate variables that vary by locality. Best-fit models to predict the presence of Ae. aegypti pupae included parameters for household water storage practices, access to piped water, the number of households per property, condition of the house and patio, and knowledge and perceptions of dengue. Rainfall and minimum temperature were significant predictors of oviposition activity, although the effect of rainfall varied by locality due to differences in types of water storage containers. CONCLUSIONS: These results indicate the potential to reduce the burden of dengue in this region by conducting focused vector control interventions that target high-risk households and containers in each season and by developing predictive models using climate and non-climate information. These findings provide the region's public health sector with key information for conducting time and location-specific vector control campaigns, and highlight the importance of local socio-ecological studies to understand dengue dynamics. See Text S1 for an executive summary in

Autoimmune features caused by dengue fever: a case report

Directory of Open Access Journals (Sweden)

Denis Leonardo Fontes Jardim

Full Text Available Dengue virus is the most important mosquito-borne viral disease in the world. Co-circulation of the four types of dengue viruses and expansion of dengue epidemic gave rise to infection enhancement and a big expansion of clinical aspects of the disease. Herein we report a case of a 25-year-old white woman with dengue fever and numerous associated autoimmune features. Our patient had proteinuria, an extensive right pleural effusion, a thin pericardial effusion and ascites. She had a low C3 level and positive antinuclear antibody; cryoglobulins were also positive. The numerous autoimmune features of this patient were a diagnostic challenge, since she was a young woman and could be easily mistaken for a rheumatologic patient in a newly open disease. Dengue infection probably was a triggering event causing an abnormal immune response. Therefore, dengue should be suspected in patients with hematological disorders and autoimmune features in endemic regions or those who have travelled to those regions.

Birth of a normal child after in vitro fertilization treatment followed by dengue fever.

Science.gov (United States)

Geber, Selmo; Coimbra, Bruna Barbosa; Geber, Guilherme Primo; Sampaio, Marcos

2014-11-01

Dengue is a serious public health issue due to its escalating aspect. It is also not yet established whether dengue has any impact on the outcome of assisted reproductive technique for infertility treatments. To our knowledge there are no published data in this subject. Therefore we describe a successful case of birth after in vitro fertilization (IVF) followed by dengue fever. A couple with primary unexplained infertility was submitted to IVF. The patient was submitted to ovulation induction with long protocol. A total of 12 oocytes were retrieved and two embryos were transferred. On the evening of the embryo transfer the patient started with headache and retro-orbital pain, followed by fever and nausea. Two days later she started with vomiting and diarrhea and epistaxis. The tourniquet test was positive. After patient's exams showed hemoconcentration and low platelet count (<50,000/mm(3)) the diagnosis of dengue hemorrhagic fever was confirmed and she was hospitalized and parenterally hydrated. As there was a good response to treatment, the patient was discharged the next day. A serum βhCG concentration 14 days after oocyte retrieval was positive. A healthy infant was born at the thirty-ninth gestational week by cesarean section. To our knowledge this is the first successful case reported on a patient who had dengue fever immediately after embryo transfer in an IVF treatment cycle. As dengue becomes a public health problem, it is important to bring attention to the subject.

Achados ultra-sonográficos abdominais em pacientes com dengue Abdominal ultrasound findings in patients with dengue fever

Directory of Open Access Journals (Sweden)

Karen Amaral do Vabo

2004-06-01

Full Text Available OBJETIVO: Apresentar os achados ultra-sonográficos abdominais em pacientes com dengue e compará-los aos descritos na literatura. MATERIAIS E MÉTODOS: Foram realizados exames ultra-sonográficos abdominais de 38 pacientes, 25 do sexo feminino e 13 do sexo masculino, com idade média de 35 anos, com diagnóstico de dengue sorologicamente confirmado. Os achados foram comparados com os descritos na literatura. RESULTADOS: Os achados ultra-sonográficos mais relevantes foram espessamento difuso da parede da vesícula biliar em 18 casos (47,4%, líquido livre na cavidade abdominal e/ou pélvica em 12 (31,6%, esplenomegalia em 11 (28,9%, hepatomegalia em 10 (26,3% e líquido pericolecístico em 10 (26,3%. Vinte e seis por cento dos pacientes apresentaram exames ultra-sonográficos normais. CONCLUSÃO: Os achados ultra-sonográficos abdominais são uma ferramenta adicional útil na confirmação de casos suspeitos de dengue hemorrágica e na detecção precoce da gravidade e da progressão da doença, sendo de extrema importância para o radiologista o conhecimento destes possíveis achados.OBJECTIVE: To review the abdominal ultrasound findings in patients with serologically proven dengue fever and to compare the results with data from the literature. MATERIALS AND METHODS: Thirty-eight patients with serologically proven dengue fever, 25 female and 13 male, mean age of 35 years, were submitted to abdominal ultrasound. The ultrasound findings were compared with data from the literature. RESULTS: The most relevant ultrasound findings were diffuse gallbladder wall thickening in 18 cases (47.4%, abdominal and/or pelvic free fluid in 12 (31.6%, splenomegaly in 11 (28.9%, hepatomegaly in 10 (26.3% and perivesicular fluid in 10 (26.3%. Twenty-six percent of the patients had normal abdominal ultrasound. CONCLUSION: Abdominal sonography is a useful additional diagnostic tool for the confirmation of suspected cases of dengue hemorrhagic fever and for the

Prevention of Dengue Fever: An Exploratory School-Community Intervention Involving Students Empowered as Change Agents

Science.gov (United States)

Jayawardene, Wasantha P.; Lohrmann, David K.; YoussefAgha, Ahmed H.; Nilwala, Dayani C.

2011-01-01

Background: Dengue fever and dengue hemorrhagic fever (DF/DHF) are epidemic and endemic in tropical and subtropical countries including Sri Lanka. Numerous structural and community interventions have been shown to be effective in interrupting the life cycle of mosquitoes that transmit DF/DHF; however, these interventions are not always implemented…

Transition in the Cause of Fever from Malaria to Dengue, Northwestern Ecuador, 1990–2011

Science.gov (United States)

Cifuentes, Sara G.; Trostle, James; Trueba, Gabriel; Milbrath, Meghan; Baldeón, Manuel E.; Coloma, Josefina

2013-01-01

In tropical areas, the predominant cause of fever has historically been malaria. However by 2011, among febrile patients in northwestern Ecuador, dengue was identified in 42% and malaria in none. This finding suggests a transition in the cause of fever from malaria to other illnesses, such as dengue. PMID:24047566

P. vivax malaria and dengue fever co-infection: a cross-sectional study in the Brazilian Amazon.

Directory of Open Access Journals (Sweden)

Belisa M L Magalhães

2014-10-01

Full Text Available Malaria and dengue are the most prevalent vector-borne diseases worldwide and represent major public health problems. Both are endemic in tropical regions, propitiating co-infection. Only few co-infection cases have been reported around the world, with insufficient data so far to enhance the understanding of the effects of co-infection in the clinical presentation and severity.A cross-sectional study was conducted (2009 to 2011 in hospitalized patients with acute febrile syndrome in the Brazilian Amazon. All patients were submitted to thick blood smear and PCR for Plasmodium sp. detection, ELISA, PCR and NS1 tests for dengue, viral hepatitis, HIV and leptospirosis. In total, 1,578 patients were recruited. Among them, 176 (11.1% presented P. vivax malaria mono-infection, 584 (37% dengue fever mono-infection, and 44 (2.8% were co-infected. Co-infected patients had a higher chance of presenting severe disease (vs. dengue mono-infected, deep bleeding (vs. P. vivax mono-infected, hepatomegaly, and jaundice (vs. dengue mono-infected.In endemic areas for dengue and malaria, jaundice (in dengue patients and spontaneous bleeding (in malaria patients should raise the suspicion of co-infection. Besides, whenever co-infection is confirmed, we recommend careful monitoring for bleeding and hepatic complications, which may result in a higher chance of severity, despite of the fact that no increased fatality rate was seen in this group.

Improving Dengue Virus Capture Rates in Humans and Vectors in Kamphaeng Phet Province, Thailand, Using an Enhanced Spatiotemporal Surveillance Strategy

Science.gov (United States)

Thomas, Stephen J.; Aldstadt, Jared; Jarman, Richard G.; Buddhari, Darunee; Yoon, In-Kyu; Richardson, Jason H.; Ponlawat, Alongkot; Iamsirithaworn, Sopon; Scott, Thomas W.; Rothman, Alan L.; Gibbons, Robert V.; Lambrechts, Louis; Endy, Timothy P.

2015-01-01

Dengue is of public health importance in tropical and sub-tropical regions. Dengue virus (DENV) transmission dynamics was studied in Kamphaeng Phet Province, Thailand, using an enhanced spatiotemporal surveillance of 93 hospitalized subjects with confirmed dengue (initiates) and associated cluster individuals (associates) with entomologic sampling. A total of 438 associates were enrolled from 208 houses with household members with a history of fever, located within a 200-m radius of an initiate case. Of 409 associates, 86 (21%) had laboratory-confirmed DENV infection. A total of 63 (1.8%) of the 3,565 mosquitoes collected were dengue polymerase chain reaction positive (PCR+). There was a significant relationship between spatial proximity to the initiate case and likelihood of detecting DENV from associate cases and Aedes mosquitoes. The viral detection rate from human hosts and mosquito vectors in this study was higher than previously observed by the study team in the same geographic area using different methodologies. We propose that the sampling strategy used in this study could support surveillance of DENV transmission and vector interactions. PMID:25986580

Enhancing the Immunogenicity of a Tetravalent Dengue DNA Vaccine

Science.gov (United States)

2016-08-01

season’s influenza vaccine. There is no overlap with the proposed project. Title: Serological survey for Zika virus and other vector-borne pathogen...studying human immunology and pathogenesis of dengue virus infection Time Commitments: 5% 0.6 calendar months Supporting Agency: Military Infectious...attenuated dengue virus vaccine (LAV), and (3) inactivated dengue virus vaccine. Dengue fever ranks among the top infectious diseases that afflict

Declining Prevalence of Disease Vectors Under Climate Change

DEFF Research Database (Denmark)

Escobar, Luis E.; Romero-Alvarez, Daniel; Leon, Renato

2016-01-01

More than half of the world population is at risk of vector-borne diseases including dengue fever, chikungunya, zika, yellow fever, leishmaniasis, chagas disease, and malaria, with highest incidences in tropical regions. In Ecuador, vector-borne diseases are present from coastal and Amazonian...

Climate and dengue transmission: evidence and implications.

Science.gov (United States)

Morin, Cory W; Comrie, Andrew C; Ernst, Kacey

2013-01-01

Climate influences dengue ecology by affecting vector dynamics, agent development, and mosquito/human interactions. Although these relationships are known, the impact climate change will have on transmission is unclear. Climate-driven statistical and process-based models are being used to refine our knowledge of these relationships and predict the effects of projected climate change on dengue fever occurrence, but results have been inconsistent. We sought to identify major climatic influences on dengue virus ecology and to evaluate the ability of climate-based dengue models to describe associations between climate and dengue, simulate outbreaks, and project the impacts of climate change. We reviewed the evidence for direct and indirect relationships between climate and dengue generated from laboratory studies, field studies, and statistical analyses of associations between vectors, dengue fever incidence, and climate conditions. We assessed the potential contribution of climate-driven, process-based dengue models and provide suggestions to improve their performance. Relationships between climate variables and factors that influence dengue transmission are complex. A climate variable may increase dengue transmission potential through one aspect of the system while simultaneously decreasing transmission potential through another. This complexity may at least partly explain inconsistencies in statistical associations between dengue and climate. Process-based models can account for the complex dynamics but often omit important aspects of dengue ecology, notably virus development and host-species interactions. Synthesizing and applying current knowledge of climatic effects on all aspects of dengue virus ecology will help direct future research and enable better projections of climate change effects on dengue incidence.

Myalgia Cruris Epidemica: an unusual presentation of dengue fever.

Science.gov (United States)

Ahmad, Rashidi; Abdul Latiff, Abdul Kursi; Abdul Razak, Salmi

2007-11-01

We describe a 5-year-old girl who had sudden onset difficulty in walking after 3 days of febrile illness. In the emergency department her creatine kinase level was elevated but urine myoglobin was normal. She was diagnosed as having benign acute childhood myositis. Because of poor oral intake and dehydration, she was admitted to the pediatric ward. The next day she had a petechial rash over the antecubital fossa, and dengue IgM back was positive. She was treated conservatively and recovered uneventfully. Despite dengue fever being endemic in Malaysia, this is the first case report of myositis following dengue infection in Malaysia.

Dengue vaccines: Challenges, development, current status and prospects

Directory of Open Access Journals (Sweden)

A Ghosh

2015-01-01

Full Text Available Infection with dengue virus (DENV is the most rapidly spreading mosquito-borne viral disease in the world. The clinical spectrum of dengue, caused by any of the four serotypes of DENV, ranges from mild self-limiting dengue fever to severe dengue, in the form dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS. Increased rates of hospitalization due to severe dengue, during outbreaks, result in massive economic losses and strained health services. In the absence of specific antiviral therapy, control of transmission of DENV by vector management is the sole method available for decreasing dengue-associated morbidity. Since vector control strategies alone have not been able to satisfactorily achieve reduction in viral transmission, the implementation of a safe, efficacious and cost-effective dengue vaccine as a supplementary measure is a high public health priority. However, the unique and complex immunopathology of dengue has complicated vaccine development. Dengue vaccines have also been challenged by critical issues like lack of animal models for the disease and absence of suitable markers of protective immunity. Although no licensed dengue vaccine is yet available, several vaccine candidates are under phases of development, including live attenuated virus vaccines, live chimeric virus vaccines, inactivated virus vaccines, subunit vaccines, DNA vaccines and viral-vectored vaccines. Although some vaccine candidates have progressed from animal trials to phase II and III in humans, a number of issues regarding implementation of dengue vaccine in countries like India still need to be addressed. Despite the current limitations, collaborative effects of regulatory bodies like World Health Organization with vaccine manufacturers and policy makers, to facilitate vaccine development and standardize field trials can make a safe and efficacious dengue vaccine a reality in near future.

Longitudinal study of Thai people media exposure, knowledge, and behavior on dengue fever prevention and control.

Science.gov (United States)

Boonchutima, Smith; Kachentawa, Kirati; Limpavithayakul, Manasanun; Prachansri, Anan

Dengue hemorrhagic fever is transmitted through a bite by a dengue -infected Aedes aegypti mosquito. It was first reported in the mid -20th century in Thailand, and since then its epidemiology has been of great concern and has spread all across the country. The alarming incidence of dengue posed a serious threat to human health in all major cities of Thailand. This study was aimed at identifying the level of awareness of dengue fever in Thai population knowledge for prevention and control, and most importantly contribution of media in educating masses for dengue control measures. It is longitudinal in nature and was conducted in 25 provinces of Thailand during 2013-2015. Approximately 7772 respondents participated in this study, with the selection of provinces based on considerations like population, prevalence and demography. A pre-tested structured questionnaire was used to collect information relevant to study participants' demographic profile, pre-existing knowledge about dengue fever and its reinforcement through media, and population attitudes toward prevention and control. Over the period of three years, a positive trend was revealed relevant to the contribution of media in educating and reminding the Thai population of dengue, without any uniformity or powerful campaigns. Based on the results drawn from this study, we conclude that despite the measures undertaken to prevent dengue fever, there is insufficient media exposure. An interdisciplinary approach involving the community participation, media, and government is needed to overcome dengue threat in Thailand. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Incidence of dengue virus infections in febrile episodes in Ile-Ife ...

African Journals Online (AJOL)

While dengue infection is accompanied by little or no subclinical signs in many, about 1-2% may produce clinically severe Dengue Haemorrhagic Fever/Dengue Shock Syndrome. Early recognition, appropriate treatment and elimination of mosquito vectors will help control it. The study is aimed at determining the incidence ...

Hemoterapia e febre Dengue Blood banking e Dengue fever

Directory of Open Access Journals (Sweden)

Estácio F. Ramos

2008-02-01

Full Text Available Dengue is an endemic/epidemic arboviral disease with a variable symptomatic benign course, but potentially fatal. Once in an inhabited area, the disease will exist forever, with the best achievement being to keep vectors suppressed and the disease under control. Tiger mosquitoes (aedes aegypti, aedes albopictus are active breeders and urban hunters, becoming resistant to pesticides. Global warming and population growth are propelling the disease worldwide at tropical and subtropical regions, victimizing new populations. Dengue virus is very infective, and has been transmitted by needlestick, intrapartum, through blood transfusion and mucosal contact with blood. One patient got dengue while undergoing bone marrow transplantation. We address the growing dengue epidemics in Brazil, with more than half a million official cases in 2007, to estimate the risks of transfusion transmitted dengue. Calculations however were surpassed by reality: the major Blood Center in Brazil (FHSP-USP has found dengue virus in one out of each thousand blood units. In 2007, industry sold 2,6 million disposable blood bags in Brazil. Plotting data from FHSP-USP to the whole country, 2600 blood units would have been infective. Through blood components, around 5000 patients must have received dengue virus intravenously. Beatty et al. estimated to be 1:1300 the risk for dengue transmission through blood transfusion in Puerto Rico, close to what has been demonstrated in Sao Paulo. Throughout Brazil, the average risk may be lower, but the epidemics grows towards a worst scenario. Whatever the risk is, it imposes that all blood units in Brazil (and wherever dengue is endemic must be EIA tested for dengue NS1 antigen. This marker appears early after infection, and the EIA testing platform is available at all blood banks. Also, donors must report febrile states up to two weeks after donation. Morbidity from dengue virus injected in hospitalized patients is unknown, but it may lead

Genetic structure and phylogeography of Aedes aegypti, the dengue and yellow-fever mosquito vector in Bolivia.

Science.gov (United States)

Paupy, Christophe; Le Goff, Gilbert; Brengues, Cécile; Guerra, Mabel; Revollo, Jimmy; Barja Simon, Zaïra; Hervé, Jean-Pierre; Fontenille, Didier

2012-08-01

Between the 16th and 18th centuries, Aedes aegypti (Diptera: Culicidae), a mosquito native to Africa, invaded the Americas, where it was successively responsible for the emergence of yellow fever (YF) and dengue (DEN). The species was eradicated from numerous American countries in the mid-20th century, but re-invaded them in the 1970s and 1980s. Little is known about the precise identities of Ae. aegypti populations which successively thrived in South America, or their relation with the epidemiological changes in patterns of YF and DEN. We examined these questions in Bolivia, where Ae. aegypti, eradicated in 1943, re-appeared in the 1980s. We assessed the genetic variability and population genetics of Ae. aegypti samples in order to deduce their genetic structure and likely geographic origin. Using a 21-population set covering Bolivia, we analyzed the polymorphism at nine microsatellite loci and in two mitochondrial DNA regions (COI and ND4). Microsatellite markers revealed a significant genetic structure among geographic populations (F(ST)=0.0627, PBolivia. Analysis of mtDNA sequences revealed the existence of two genetic lineages, one dominant lineage recovered throughout Bolivia, and the second restricted to rural localities in South Bolivia. Phylogenic analysis indicated that this minority lineage was related to West African Ae. aegypti specimens. In conclusion, our results suggested a temporal succession of Ae. aegypti populations in Bolivia, that potentially impacted the epidemiology of dengue and yellow fever. Copyright © 2012 Elsevier B.V. All rights reserved.

Clinical and laboratory features of dengue virus-infected travellers previously vaccinated against yellow fever

NARCIS (Netherlands)

Teichmann, Dieter; Göbels, Klaus; Niedrig, Matthias; Grobusch, Martin P.

2003-01-01

Dengue is a mosquito-borne viral infection endemic throughout the tropics and subtropics. The global prevalence of dengue has grown dramatically in recent years and it has become a major international public health concern. The close taxonomic relationships between yellow fever and dengue viruses

Humoral immune responses of dengue fever patients using epitope-specific serotype-2 virus-like particle antigens.

Directory of Open Access Journals (Sweden)

Wayne D Crill

Full Text Available Dengue virus (DENV is a serious mosquito-borne pathogen causing significant global disease burden, either as classic dengue fever (DF or in its most severe manifestation dengue hemorrhagic fever (DHF. Nearly half of the world's population is at risk of dengue disease and there are estimated to be millions of infections annually; a situation which will continue to worsen with increasing expansion of the mosquito vectors and epidemic DF/DHF. Currently there are no available licensed vaccines or antivirals for dengue, although significant effort has been directed toward the development of safe and efficacious dengue vaccines for over 30 years. Promising vaccine candidates are in development and testing phases, but a better understanding of immune responses to DENV infection and vaccination is needed. Humoral immune responses to DENV infection are complex and may exacerbate pathogenicity, yet are essential for immune protection. In this report, we develop DENV-2 envelope (E protein epitope-specific antigens and measure immunoglobulin responses to three distinct epitopes in DENV-2 infected human serum samples. Immunoglobulin responses to DENV-2 infection exhibited significant levels of individual variation. Antibody populations targeting broadly cross-reactive epitopes centered on the fusion peptide in structural domain II were large, highly variable, and greater in primary than in secondary DENV-2 infected sera. E protein domain III cross-reactive immunoglobulin populations were similarly variable and much larger in IgM than in IgG. DENV-2 specific domain III IgG formed a very small proportion of the antibody response yet was significantly correlated with DENV-2 neutralization, suggesting that the highly protective IgG recognizing this epitope in murine studies plays a role in humans as well. This report begins to tease apart complex humoral immune responses to DENV infection and is thus important for improving our understanding of dengue disease

Dengue and the risk of urban yellow fever reintroduction in São Paulo State, Brazil Dengue e risco da reintrodução da febre amarela urbana no Estado de São Paulo

Directory of Open Access Journals (Sweden)

Eduardo Massad

2003-08-01

Full Text Available OBJECTIVE: To propose a mathematical method for the estimation of the Basic Reproduction Number, R0, of urban yellow fever in a dengue-infested area. METHODS: The method is based on the assumption that, as the same vector (Aedes aegypti causes both infections, all the quantities related to the mosquito, estimated from the initial phase of dengue epidemic, could be applied to yellow fever dynamics. It is demonstrated that R0 for yellow fever is, on average, 43% lower than that for dengue. This difference is due to the longer dengue viremia and its shorter extrinsic incubation period. RESULTS: In this study the analysis was expanded to the epidemiological situation of dengue in São Paulo in the year 2001. The total number of dengue cases increased from 3,582 in 2000 to 51,348 in 2001. It was then calculated R0 for yellow fever for every city which have shown R0 of dengue greater than 1. It was also estimated the total number of unprotected people living in highly risky areas for urban yellow fever. CONCLUSIONS: Currently there is a great number of non-vaccinated people living in Aedes aegypti infested area in the state of São Paulo.OBJETIVO: Propor um modelo matemático para a estimativa da reprodutibilidade basal, R0, para a febre amarela urbana em uma área infestada pela dengue. MÉTODOS: O método utilizado considera que, como ambas as doenças são transmitidas pelo mesmo vetor (Aedes aegypti, poder-se-ia aplicar todos os parâmetros quantitativos relativos ao mosquito, estimados pela fase inicial da curva de crescimento de casos de dengue, à dinâmica da febre amarela. Demonstra-se que o R0 da febre amarela é em média 43% menor que o da dengue. Esta diferença deve-se à viremia mais prolongada da dengue, bem como ao menor período de incubação extrínseco daquele vírus no mosquito. RESULTADOS: Apresenta-se a aplicação desta análise matemática à situação epidemiológica da dengue no estado de São Paulo, para o ano de 2001

A review of dengue fever incidence in Kota Bharu, Kelantan, Malaysia during the years 1998-2003.

Science.gov (United States)

Hussin, Narwani; Jaafar, Jesni; Naing, Nyi Nyi; Mat, Hamzah Ag; Muhamad, Abd Haris; Mamat, Mohd Noor

2005-09-01

Dengue is the most common and widespread arthropod borne arboviral infection in the world today. It is estimated that there are at least 100 million cases of dengue fever (DF) annually and 500,000 cases of dengue hemorrhagic fever (DHF) which require hospitalization. In Malaysia, it has become a major public health problem. Malaysia recorded 19,544 dengue cases in 1997, the highest recorded since the disease was made notifiable in the country. Of 19,544 cases, 806 were DHF with 50 deaths. The objectives of this analysis were to describe the incidence of dengue fever and dengue hemorrhagic fever in Kota Bharu, Kelantan, Malaysia for the years 1998-2003 and to explore the characteristics of dengue fever and dengue hemorrhagic fever in Kota Bharu, Kelantan, Malaysia for years 1998-2003. A total of 4,716 dengue cases were notified involving 4,476 (94.9%) DF and 240 (5.1%) DHF cases, which increased though the years. The highest incidence was in January (701 or 14.9%), while the lowest was in May (188 or 4.0%). Forty percent of cases (n=1,890) were in the 15-29 year old group. The Majority were Malays (4,062 or 86.1%) and 2,602 or 55.2% were male. A total of 4,477 cases (95%) were local cases and 4,289 or 91% came from the urban area. For priority areas, 3,772 (80%) were from priority 1. More than half the cases had positive serology results. All symptoms occurred in more than 96% of cases and fever was the commonest (99.7%). The mean values for age, temperature, systolic and diastolic blood pressure (BP) were 27.8 +/- 15.4 years, 37.9 +/- 0.90 degrees C, 115 +/- 15.2 mmHg and 73 +/- 11.1 mmHg, respectively. The mean value for the time interval between the onset of symptoms and diagnosis, onset of symptoms and notification and time of diagnosis to notification were 5.1 +/- 2.3, 5.9 +/- 2.5 and 0.8 +/- 1.1 days, respectively. There were associations between the types of dengue and classification, area and priority area. Among the symptoms, the association was only seen

Pathologic highlights of dengue hemorrhagic fever in 13 autopsy cases from Myanmar.

Science.gov (United States)

Aye, Khin Saw; Charngkaew, Komgrid; Win, Ne; Wai, Kyaw Zin; Moe, Kyaw; Punyadee, Nuntaya; Thiemmeca, Somchai; Suttitheptumrong, Aroonroong; Sukpanichnant, Sanya; Prida, Malasit; Halstead, Scott B

2014-06-01

Vascular permeability, thrombocytopenia, liver pathology, complement activation, and altered hemostasis accompanying a febrile disease are the hallmarks of the dengue hemorrhagic fever/dengue shock syndrome, a major arthropod-borne viral disease that causes significant morbidity and mortality throughout tropical countries. We studied tissues from 13 children who died of acute dengue hemorrhagic fever/dengue shock syndrome at the Childrens' Hospital, Yangon, Myanmar. Dengue viral RNA from each of the 4 dengue viruses (DENVs) was detected by reverse transcriptase polymerase chain reaction in 11 cases, and dengue viral proteins (envelope, NS1, or NS3) were detected in 1 or more tissues from all 13 cases. Formalin-fixed and frozen tissues were studied for evidence of virus infection using monoclonal antibodies against DENV structural and nonstructural antigens (E, NS1, and nonsecreting NS3). In the liver, DENV infection occurred in hepatocytes and Kupffer cells but not in endothelial cells. Liver damage was associated with deposition on hepatocytes of complement components of both classical and alternative pathways. Evidence of dengue viral replication was observed in macrophage-like cells in spleens and lymph nodes. No dengue antigens were detected in endothelial cells in any organ. Germinal centers of the spleen and lymph nodes showed a marked reduction in the number of lymphocytes that were replaced by eosinophilic deposits, which contained dengue antigens as well as immunoglobulins, and complement components (C3, C1q, and C9). The latter findings had previously been reported but overlooked as a diagnostic feature. Copyright © 2014 Elsevier Inc. All rights reserved.

An unusual case of osteonecrosis of the jaw associated with dengue fever and periodontitis.

Science.gov (United States)

Indurkar, M S; Sethi, R

2016-03-01

Osteonecrosis is a disorder rarely occurring in the jaw. Dengue fever is a common mosquito-borne disease prevalent in many countries including India. The following report presents an interesting case of maxillary osteonecrosis in a middle aged male with a history of dengue infection. We also diagnosed symptoms of chronic periodontitis, which may have potentiated the necrosis. This case report will describe a novel clinical presentation and management of osteonecrosis of the jaw (ONJ) of unknown origin and a possible pathogenesis explaining the association of ONJ with dengue fever and periodontitis. © 2015 Australian Dental Association.

El Nino Southern Oscillation and vegetation dynamics as predictors of dengue fever cases in Costa Rica

Energy Technology Data Exchange (ETDEWEB)

Fuller, D O [Department of Geography and Regional Studies, University of Miami, Coral Gables, FL 33124-2221 (United States); Troyo, A [Centro de Investigacion en Enfermedades Tropicales, Departamento de ParasitologIa, Facultad de MicrobiologIa, Universidad de Costa Rica, San Jose (Costa Rica); Beier, J C [Global Public Health Program, Department of Epidemiology and Public Health, University of Miami, Miami, FL (United States)], E-mail: dofuller@miami.edu

2009-01-15

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are growing health concerns throughout Latin America and the Caribbean. This study focuses on Costa Rica, which experienced over 100 000 cases of DF/DHF from 2003 to 2007. We utilized data on sea-surface temperature anomalies related to the El Nino Southern Oscillation (ENSO) and two vegetation indices derived from the Moderate Resolution Imaging Spectrometer (MODIS) from the Terra satellite to model the influence of climate and vegetation dynamics on DF/DHF cases in Costa Rica. Cross-correlations were calculated to evaluate both positive and negative lag effects on the relationships between independent variables and DF/DHF cases. The model, which utilizes a sinusoid and non-linear least squares to fit case data, was able to explain 83% of the variance in weekly DF/DHF cases when independent variables were shifted backwards in time. When the independent variables were shifted forward in time, consistently with a forecasting approach, the model explained 64% of the variance. Importantly, when five ENSO and two vegetation indices were included, the model reproduced a major DF/DHF epidemic of 2005. The unexplained variance in the model may be due to herd immunity and vector control measures, although information regarding these aspects of the disease system are generally lacking. Our analysis suggests that the model may be used to predict DF/DHF outbreaks as early as 40 weeks in advance and may also provide valuable information on the magnitude of future epidemics. In its current form it may be used to inform national vector control programs and policies regarding control measures; it is the first climate-based dengue model developed for this country and is potentially scalable to the broader region of Latin America and the Caribbean where dramatic increases in DF/DHF incidence and spread have been observed.

El Nino Southern Oscillation and vegetation dynamics as predictors of dengue fever cases in Costa Rica

International Nuclear Information System (INIS)

Fuller, D O; Troyo, A; Beier, J C

2009-01-01

Dengue fever (DF) and dengue hemorrhagic fever (DHF) are growing health concerns throughout Latin America and the Caribbean. This study focuses on Costa Rica, which experienced over 100 000 cases of DF/DHF from 2003 to 2007. We utilized data on sea-surface temperature anomalies related to the El Nino Southern Oscillation (ENSO) and two vegetation indices derived from the Moderate Resolution Imaging Spectrometer (MODIS) from the Terra satellite to model the influence of climate and vegetation dynamics on DF/DHF cases in Costa Rica. Cross-correlations were calculated to evaluate both positive and negative lag effects on the relationships between independent variables and DF/DHF cases. The model, which utilizes a sinusoid and non-linear least squares to fit case data, was able to explain 83% of the variance in weekly DF/DHF cases when independent variables were shifted backwards in time. When the independent variables were shifted forward in time, consistently with a forecasting approach, the model explained 64% of the variance. Importantly, when five ENSO and two vegetation indices were included, the model reproduced a major DF/DHF epidemic of 2005. The unexplained variance in the model may be due to herd immunity and vector control measures, although information regarding these aspects of the disease system are generally lacking. Our analysis suggests that the model may be used to predict DF/DHF outbreaks as early as 40 weeks in advance and may also provide valuable information on the magnitude of future epidemics. In its current form it may be used to inform national vector control programs and policies regarding control measures; it is the first climate-based dengue model developed for this country and is potentially scalable to the broader region of Latin America and the Caribbean where dramatic increases in DF/DHF incidence and spread have been observed.

Genetic differentiation in populations of Aedes aegypti (Diptera, Culicidae dengue vector from the Brazilian state of Maranhão

Directory of Open Access Journals (Sweden)

Andrelina Alves de Sousa

Full Text Available ABSTRACT Aedes (Stegomyia aegypti is the vector responsible for the transmission of the viruses that cause zika, yellow and chikungunya fevers, the four dengue fever serotypes (DENV - 1, 2, 3, 4, and hemorrhagic dengue fever in tropical and subtropical regions around the world. The present study investigated the genetic differentiation of the 15 populations of this vector in the Brazilian state of Maranhão, based on the mitochondrial ND4 marker. A total of 177 sequences were obtained for Aedes aegypti, with a fragment of 337 bps, 15 haplotypes, 15 polymorphics sites, haplotype diversity of h = 0.6938, and nucleotide diversity of π = 0.01486. The neutrality tests (D and Fs were not significant. The AMOVA revealed that most of the variation (58.47% was found within populations, with FST = 0.41533 (p < 0.05. Possible isolation by distance was tested and a significant correlation coefficient (r = 0.3486; p = 0.0040 was found using the Mantel test. The phylogenetic relationships among the 15 haplotypes indicated the existence of two distinct clades. This finding, together with the population parameters, was consistent with a pattern of genetic structuring that underpinned the genetic differentiation of the study populations in Maranhão, and was characterized by the presence of distinct lineages of Aedes aegypti.

Dengue Fever Seroprevalence and Risk Factors, Texas-Mexico Border, 2004

Centers for Disease Control (CDC) Podcasts

Dengue fever is both endemic and underrecognized along a section of the southern Texas–Mexico border, and low income is a primary risk factor for infection. As part of a special section on Global Poverty and Human Development, Dr. Joan Marie Brunkard discusses a dengue seroprevalence survey in this region and what can be done to help prevent infection and to identify and treat those who are infected.

Effectiveness of a fluid chart in outpatient management of suspected dengue fever: A pilot study.

Science.gov (United States)

Nasir, Nazrila Hairin; Mohamad, Mohazmi; Lum, Lucy Chai See; Ng, Chirk Jenn

2017-01-01

Dengue infection is the fastest spreading mosquito-borne viral disease in the world. One of the complications of dengue is dehydration which, if not carefully monitored and treated, may lead to shock, particularly in those with dengue haemorrhagic fever. WHO has recommended oral fluid intake of five glasses or more for adults who are suspected to have dengue fever. However, there have been no published studies looking at self-care intervention measures to improve oral fluid intake among patients suspected of dengue fever. To assess the feasibility and effectiveness of using a fluid chart to improve oral fluid intake in patients with suspected dengue fever in a primary care setting. This feasibility study used a randomized controlled study design. The data was collected over two months at a primary care clinic in a teaching hospital. The inclusion criteria were: age > 12 years, patients who were suspected to have dengue fever based on the assessment by the primary healthcare clinician, fever for > three days, and thrombocytopenia (platelets dengue home care card. The intervention group received the fluid chart and a cup (200ml). Baseline clinical and laboratory data, 24-hour fluid recall (control group), and fluid chart were collected. The main outcomes were: hospitalization rates, intravenous fluid requirement and total oral fluid intake. Among the 138 participants who were included in the final analysis, there were fewer hospital admissions in the intervention group (n = 7, 10.0%) than the control group (n = 12, 17.6%) (p = 0.192). Similarly, fewer patients (n = 9, 12.9%) in the intervention group required intravenous fluid compared to the control group (n = 15, 22.1%), (p = 0.154). There was an increase in the amount of daily oral fluid intake in the intervention group (about 3,000 ml) compared to the control group (about 2,500 ml, p = 0.521). However, these differences did not reach statistical significance. This is a feasible and acceptable study to perform in

Severe coinfection of melioidosis and dengue fever in northeastern Brazil: first case report

Directory of Open Access Journals (Sweden)

Rafael Nogueira Macedo

2012-02-01

Full Text Available This report focuses on a fatality involving severe dengue fever and melioidosis in a 28-year-old truck driver residing in Pacoti in northeastern Brazil. He exhibited long-term respiratory symptoms (48 days and went through a wide-ranging clinical investigation at three hospitals, after initial clinical diagnoses of pneumonia, visceral leishmaniasis, tuberculosis, and fungal sepsis. After death, Burkholderia pseudomallei was isolated in a culture of ascitic fluid. Dengue virus type 1 was detected by polymerase chain reaction in cerebrospinal fluid (CSF; this infection was the cause of death. This description reinforces the need to consider melioidosis among the reported differential diagnoses of community-acquired infections where both melioidosis and dengue fever are endemic.

A critical assessment of vector control for dengue prevention.

Directory of Open Access Journals (Sweden)

Nicole L Achee

2015-05-01

Full Text Available Recently, the Vaccines to Vaccinate (v2V initiative was reconfigured into the Partnership for Dengue Control (PDC, a multi-sponsored and independent initiative. This redirection is consistent with the growing consensus among the dengue-prevention community that no single intervention will be sufficient to control dengue disease. The PDC's expectation is that when an effective dengue virus (DENV vaccine is commercially available, the public health community will continue to rely on vector control because the two strategies complement and enhance one another. Although the concept of integrated intervention for dengue prevention is gaining increasingly broader acceptance, to date, no consensus has been reached regarding the details of how and what combination of approaches can be most effectively implemented to manage disease. To fill that gap, the PDC proposed a three step process: (1 a critical assessment of current vector control tools and those under development, (2 outlining a research agenda for determining, in a definitive way, what existing tools work best, and (3 determining how to combine the best vector control options, which have systematically been defined in this process, with DENV vaccines. To address the first step, the PDC convened a meeting of international experts during November 2013 in Washington, DC, to critically assess existing vector control interventions and tools under development. This report summarizes those deliberations.

Dengue fever in the San Juan Bay Estuary: Evaluating the ...

Science.gov (United States)

Dengue is transmitted by Aedes aegypti, a species that thrives in cities. Here we ask which elements within the urban environment could be managed to reduce the potential for Dengue occurrence. In particular, we study the potential of wetlands in the SJBE to buffer from vector proliferation. Wetlands provide ecosystem services such as heat and water hazard mitigation, water purification and habitat for a diversity of species, all of which are factors that have been shown to affect Dengue vectors. As such, we hypothesize that within coastal neighborhoods in the SJBE wetlands, ecosystem services lead to lower Dengue occurrence. We test this hypothesis using Dengue data from 2010-2013, which includes the largest epidemic in PR history. Our analytical model includes relevant socio-economic factors and environmental controls that may also affect Dengue dynamics. Results indicated a negative effect of neighborhood mangrove cover and a positive effect of percent flood area on Dengue prevalence. Moreover, heat hazards were positively correlated with dengue prevalence and negatively correlated with neighborhood mangrove cover. Dengue prevalence did not correlate with herbaceous wetlands, or with the ecosystem services of water quality or vertebrate species richness. Mosquito borne diseases are an increasingly important health concern, which pose great challenges for safe and sustainable control and eradication. This reality calls for management approaches that consider m

Assessing dengue outbreak areas using vector surveillance in north east district, Penang Island, Malaysia

Directory of Open Access Journals (Sweden)

Ahmad Mohiddin

2015-11-01

Full Text Available Objective: To understand the efficacy of ovitrap surveillance and its implementation on monitoring reflection upon case occurrence in relation to climate variables. Methods: We used routinely setup ovitrap surveillance to monitor the mosquito populations in previous outbreak areas. Ovitraps were installed weekly at three localities that experienced high number of dengue cases (Flat Hamna, Kampung Sungai Gelugor and Kampung Tanjung Tokong from January 2010 to February 2011. Ovitraps and paddles were brought back to the laboratory and all of the water contents were poured into an enamel pan. Aged tap water was added into the enamel pan and eggs were allowed to hatch. The hatching larvae were counted after 3 days. The hatched larvae were identified at the 3rd instar larval stage. The ovitrap indices and mean number of larvae were analyzed using student t-test and One-way ANOVA. Spearmen’s rank correlation coefficient was used to determine the relation between meteorology variables and dengue fever cases. Results: Aedes albopictus was found as dominant species followed by Aedes aegypti recorded in all three study areas. Aedes aegypti preferred to breed outdoor with larvae collection, which was higher than indoor (72.37%. There was a positive correlation between the ovitrap index with the rainfall and humidity except in Kampung Tanjung Tokong. Our result also showed negative correlation between temperature and ovitrap index in all localities. Conclusions: This study provides useful data to be adapted in dengue vector management. It is very important to understand the fluctuation of vector population according to the seasonal activity, which can help us to improve our control programs. However, other factors might also contribute to the increment of dengue outbreak such as the number of available breeding sites, behavior of the vector against environmental factors and the cleanliness of the environment.

Tracking the return of Aedes aegypti to Brazil, the major vector of the dengue, chikungunya and Zika viruses.

Science.gov (United States)

Kotsakiozi, Panayiota; Gloria-Soria, Andrea; Caccone, Adalgisa; Evans, Benjamin; Schama, Renata; Martins, Ademir Jesus; Powell, Jeffrey R

2017-07-01

Aedes aegypti, commonly known as "the yellow fever mosquito", is of great medical concern today primarily as the major vector of dengue, chikungunya and Zika viruses, although yellow fever remains a serious health concern in some regions. The history of Ae. aegypti in Brazil is of particular interest because the country was subjected to a well-documented eradication program during 1940s-1950s. After cessation of the campaign, the mosquito quickly re-established in the early 1970s with several dengue outbreaks reported during the last 30 years. Brazil can be considered the country suffering the most from the yellow fever mosquito, given the high number of dengue, chikungunya and Zika cases reported in the country, after having once been declared "free of Ae. aegypti". We used 12 microsatellite markers to infer the genetic structure of Brazilian Ae. aegypti populations, genetic variability, genetic affinities with neighboring geographic areas, and the timing of their arrival and spread. This enabled us to reconstruct their recent history and evaluate whether the reappearance in Brazil was the result of re-invasion from neighboring non-eradicated areas or re-emergence from local refugia surviving the eradication program. Our results indicate a genetic break separating the northern and southern Brazilian Ae. aegypti populations, with further genetic differentiation within each cluster, especially in southern Brazil. Based on our results, re-invasions from non-eradicated regions are the most likely scenario for the reappearance of Ae. aegypti in Brazil. While populations in the northern cluster are likely to have descended from Venezuela populations as early as the 1970s, southern populations seem to have derived more recently from northern Brazilian areas. Possible entry points are also revealed within both southern and northern clusters that could inform strategies to control and monitor this important arbovirus vector.

Tracking the return of Aedes aegypti to Brazil, the major vector of the dengue, chikungunya and Zika viruses.

Directory of Open Access Journals (Sweden)

Panayiota Kotsakiozi

2017-07-01

Full Text Available Aedes aegypti, commonly known as "the yellow fever mosquito", is of great medical concern today primarily as the major vector of dengue, chikungunya and Zika viruses, although yellow fever remains a serious health concern in some regions. The history of Ae. aegypti in Brazil is of particular interest because the country was subjected to a well-documented eradication program during 1940s-1950s. After cessation of the campaign, the mosquito quickly re-established in the early 1970s with several dengue outbreaks reported during the last 30 years. Brazil can be considered the country suffering the most from the yellow fever mosquito, given the high number of dengue, chikungunya and Zika cases reported in the country, after having once been declared "free of Ae. aegypti".We used 12 microsatellite markers to infer the genetic structure of Brazilian Ae. aegypti populations, genetic variability, genetic affinities with neighboring geographic areas, and the timing of their arrival and spread. This enabled us to reconstruct their recent history and evaluate whether the reappearance in Brazil was the result of re-invasion from neighboring non-eradicated areas or re-emergence from local refugia surviving the eradication program. Our results indicate a genetic break separating the northern and southern Brazilian Ae. aegypti populations, with further genetic differentiation within each cluster, especially in southern Brazil.Based on our results, re-invasions from non-eradicated regions are the most likely scenario for the reappearance of Ae. aegypti in Brazil. While populations in the northern cluster are likely to have descended from Venezuela populations as early as the 1970s, southern populations seem to have derived more recently from northern Brazilian areas. Possible entry points are also revealed within both southern and northern clusters that could inform strategies to control and monitor this important arbovirus vector.

Spatiotemporal responses of dengue fever transmission to the road network in an urban area.

Science.gov (United States)

Li, Qiaoxuan; Cao, Wei; Ren, Hongyan; Ji, Zhonglin; Jiang, Huixian

2018-07-01

Urbanization is one of the important factors leading to the spread of dengue fever. Recently, some studies found that the road network as an urbanization factor affects the distribution and spread of dengue epidemic, but the study of relationship between the distribution of dengue epidemic and road network is limited, especially in highly urbanized areas. This study explores the temporal and spatial spread characteristics of dengue fever in the distribution of road network by observing a dengue epidemic in the southern Chinese cities. Geographic information technology is used to extract the spatial location of cases and explore the temporal and spatial changes of dengue epidemic and its spatial relationship with road network. The results showed that there was a significant "severe" period in the temporal change of dengue epidemic situation, and the cases were mainly concentrated in the vicinity of narrow roads, the spread of the epidemic mainly along the high-density road network area. These results show that high-density road network is an important factor to the direction and scale of dengue epidemic. This information may be helpful to the development of related epidemic prevention and control strategies. Copyright © 2018. Published by Elsevier B.V.

Spatio-temporal distribution of Aedes aegypti (Diptera: Culicidae mitochondrial lineages in cities with distinct dengue incidence rates suggests complex population dynamics of the dengue vector in Colombia.

Directory of Open Access Journals (Sweden)

Jeiczon Jaimes-Dueñez

2015-04-01

Full Text Available Aedes aegypti is the primary vector of the four serotypes of dengue virus (DENV1-4, Chikungunya and yellow fever virus to humans. Previous population genetic studies have revealed a particular genetic structure among the vector populations in the Americas that suggests differences in the ability to transmit DENV. In Colombia, despite its high epidemiologic importance, the genetic population structure and the phylogeographic depiction of Ae. aegypti, as well as its relationship with the epidemiologic landscapes in cities with heterogeneous incidence levels, remains unknown. We conducted a spatiotemporal analysis with the aim of determining the genetic structure and phylogeography of Colombian populations of Ae. aegypti among cities with different eco-epidemiologic characteristics with regard to DENV.Mitochondrial cytochrome oxidase C subunit 1 (COI--NADH dehydrogenase subunit 4 (ND4 genes were sequenced and analyzed from 341 adult mosquitoes collected during 2012 and 2013 in the Colombian cities of Bello, Riohacha and Villavicencio, which exhibit low, medium and high levels of incidence of DENV, respectively. The results demonstrated a low genetic differentiation over time and a high genetic structure between the cities due to changes in the frequency of two highly supported genetic groups. The phylogeographic analyses indicated that one group (associated with West African populations was found in all the cities throughout the sampling while the second group (associated with East African populations was found in all the samples from Bello and in only one sampling from Riohacha. Environmental factors such as the use of chemical insecticides showed a significant correlation with decreasing genetic diversity, indicating that environmental factors affect the population structure of Ae. aegypti across time and space in these cities.Our results suggest that two Ae. aegypti lineages are present in Colombia; one that is widespread and related to a West

Spatial-temporal analysis of dengue deaths: identifying social vulnerabilities.

Science.gov (United States)

Silva, Maria do Socorro da; Branco, Maria Dos Remédios Freitas Carvalho; Aquino, José; Queiroz, Rejane Christine de Sousa; Bani, Emanuele; Moreira, Emnielle Pinto Borges; Medeiros, Maria Nilza Lima; Rodrigues, Zulimar Márita Ribeiro

2017-01-01

Currently, dengue fever, chikungunya fever, and zika virus represent serious public health issues in Brazil, despite efforts to control the vector, the Aedes aegypti mosquito. This was a descriptive and ecological study of dengue deaths occurring from 2002 to 2013 in São Luis, Maranhão, Brazil. Geoprocessing software was used to draw maps, linking the geo-referenced deaths with urban/social data at census tract level. There were 74 deaths, concentrated in areas of social vulnerability. The use of geo-technology tools pointed to a concentration of dengue deaths in specific intra-urban areas.

Aedes mosquito salivary immune peptides: boost or block dengue viral infections

Directory of Open Access Journals (Sweden)

Natthanej Luplertlop

2014-02-01

Full Text Available Dengue virus, one of the most important arthropod-borne viruses, infected to human can severely cause dengue hemorrhagic fever and dengue shock syndrome. There are expected about 50 million dengue infections and 500 000 individuals are hospitalized with dengue hemorrhagic fever, mainly in Southeast Asia, Pacific, and in Americas reported each year. The rapid expansion of global dengue is one of a major public health challenge, together with not yet successful solutions of dengue epidemic control strategies. Thus, these dynamic dengue viral infections exhibited high demographic, societal, and public health infrastructure impacts on human. This review aimed to highlight the current understanding of dengue mosquito immune responses and role of mosquito salivary glands on dengue infection. These information may provide a valuable knowledge of disease pathogenesis, especially in mosquito vector and dengue virus interaction, which may help to control and prevent dengue distribution.

P. vivax Malaria and Dengue Fever Co-infection: A Cross-Sectional Study in the Brazilian Amazon

Science.gov (United States)

Magalhães, Belisa M. L.; Siqueira, André M.; Alexandre, Márcia A. A.; Souza, Marcela S.; Gimaque, João B.; Bastos, Michele S.; Figueiredo, Regina M. P.; Melo, Gisely C.; Lacerda, Marcus V. G.; Mourão, Maria P. G.

2014-01-01

Background Malaria and dengue are the most prevalent vector-borne diseases worldwide and represent major public health problems. Both are endemic in tropical regions, propitiating co-infection. Only few co-infection cases have been reported around the world, with insufficient data so far to enhance the understanding of the effects of co-infection in the clinical presentation and severity. Methodology/Principal Findings A cross-sectional study was conducted (2009 to 2011) in hospitalized patients with acute febrile syndrome in the Brazilian Amazon. All patients were submitted to thick blood smear and PCR for Plasmodium sp. detection, ELISA, PCR and NS1 tests for dengue, viral hepatitis, HIV and leptospirosis. In total, 1,578 patients were recruited. Among them, 176 (11.1%) presented P. vivax malaria mono-infection, 584 (37%) dengue fever mono-infection, and 44 (2.8%) were co-infected. Co-infected patients had a higher chance of presenting severe disease (vs. dengue mono-infected), deep bleeding (vs. P. vivax mono-infected), hepatomegaly, and jaundice (vs. dengue mono-infected). Conclusions/Significance In endemic areas for dengue and malaria, jaundice (in dengue patients) and spontaneous bleeding (in malaria patients) should raise the suspicion of co-infection. Besides, whenever co-infection is confirmed, we recommend careful monitoring for bleeding and hepatic complications, which may result in a higher chance of severity, despite of the fact that no increased fatality rate was seen in this group. PMID:25340346

A multi-country study of the economic burden of dengue fever: Vietnam, Thailand, and Colombia.

Science.gov (United States)

Lee, Jung-Seok; Mogasale, Vittal; Lim, Jacqueline K; Carabali, Mabel; Lee, Kang-Sung; Sirivichayakul, Chukiat; Dang, Duc Anh; Palencia-Florez, Diana Cristina; Nguyen, Thi Hien Anh; Riewpaiboon, Arthorn; Chanthavanich, Pornthep; Villar, Luis; Maskery, Brian A; Farlow, Andrew

2017-10-01

Dengue fever is a major public health concern in many parts of the tropics and subtropics. The first dengue vaccine has already been licensed in six countries. Given the growing interests in the effective use of the vaccine, it is critical to understand the economic burden of dengue fever to guide decision-makers in setting health policy priorities. A standardized cost-of-illness study was conducted in three dengue endemic countries: Vietnam, Thailand, and Colombia. In order to capture all costs during the entire period of illness, patients were tested with rapid diagnostic tests on the first day of their clinical visits, and multiple interviews were scheduled until the patients recovered from the current illness. Various cost items were collected such as direct medical and non-medical costs, indirect costs, and non-out-of-pocket costs. In addition, socio-economic factors affecting disease severity were also identified by adopting a logit model. We found that total cost per episode ranges from $141 to $385 for inpatient and from $40 to $158 outpatient, with Colombia having the highest and Thailand having the lowest. The percentage of the private economic burden of dengue fever was highest in the low-income group and lowest in the high-income group. The logit analyses showed that early treatment, higher education, and better knowledge of dengue disease would reduce the probability of developing more severe illness. The cost of dengue fever is substantial in the three dengue endemic countries. Our study findings can be used to consider accelerated introduction of vaccines into the public and private sector programs and prioritize alternative health interventions among competing health problems. In addition, a community would be better off by propagating the socio-economic factors identified in this study, which may prevent its members from developing severe illness in the long run.

Identification of Dengue and Chikungunya Cases Among Suspected Cases of Yellow Fever in the Democratic Republic of the Congo.

Science.gov (United States)

Makiala-Mandanda, Sheila; Ahuka-Mundeke, Steve; Abbate, Jessica L; Pukuta-Simbu, Elisabeth; Nsio-Mbeta, Justus; Berthet, Nicolas; Leroy, Eric Maurice; Becquart, Pierre; Muyembe-Tamfum, Jean-Jacques

2018-05-16

For more than 95% of acute febrile jaundice cases identified through surveillance for yellow fever, a reemerging arthropod-borne viral disease, no etiological exploration is ever done. The aim of this study was to test for other arthropod-borne viruses that can induce the same symptoms in patients enrolled in the yellow fever surveillance in the Democratic Republic of the Congo (DRC). Of 652 patients included in the surveillance of yellow fever in DRC from January 2003 to January 2012, 453 patients that tested negative for yellow fever virus (YFV) immunoglobulin M (IgM) antibodies were selected for the study. Real-time polymerase chain reaction was performed for the detection of dengue, West Nile, Chikungunya, O'nyong-nyong, Rift Valley fever, Zika, and YFV. The average age of patients was 22.1 years. We reported 16 cases (3.5%; confidence interval [CI]: 0.8-5.2) of dengue (serotypes 1 and 2) and 2 cases (0.4%; CI: 0.0-1.0) of Chikungunya. Three patients were co-infected with the two serotypes of dengue virus. Three cases of dengue were found in early July 2010 from the city of Titule (Oriental province) during a laboratory-confirmed outbreak of yellow fever, suggesting simultaneous circulation of dengue and yellow fever viruses. This study showed that dengue and Chikungunya viruses are potential causes of acute febrile jaundice in the DRC and highlights the need to consider dengue and Chikungunya diagnosis in the integrated disease surveillance and response program in the DRC. A prospective study is necessary to establish the epidemiology of these diseases.

Infection of Mosquito Cells (C6/36) by Dengue-2 Virus Interferes with Subsequent Infection by Yellow Fever Virus.

Science.gov (United States)

Abrao, Emiliana Pereira; da Fonseca, Benedito Antônio Lopes

2016-02-01

Dengue is one of the most important diseases caused by arboviruses in the world. Yellow fever is another arthropod-borne disease of great importance to public health that is endemic to tropical regions of Africa and the Americas. Both yellow fever and dengue viruses are flaviviruses transmitted by Aedes aegypti mosquitoes, and then, it is reasonable to consider that in a given moment, mosquito cells could be coinfected by both viruses. Therefore, we decided to evaluate if sequential infections of dengue and yellow fever viruses (and vice-versa) in mosquito cells could affect the virus replication patterns. Using immunofluorescence and real-time PCR-based replication assays in Aedes albopictus C6/36 cells with single or sequential infections with both viruses, we demonstrated the occurrence of viral interference, also called superinfection exclusion, between these two viruses. Our results show that this interference pattern is particularly evident when cells were first infected with dengue virus and subsequently with yellow fever virus (YFV). Reduction in dengue virus replication, although to a lower extent, was also observed when C6/36 cells were initially infected with YFV followed by dengue virus infection. Although the importance that these findings have on nature is unknown, this study provides evidence, at the cellular level, of the occurrence of replication interference between dengue and yellow fever viruses and raises the question if superinfection exclusion could be a possible explanation, at least partially, for the reported lack of urban yellow fever occurrence in regions where a high level of dengue transmission occurs.

Malaria and Other Vector-Borne Infection Surveillance in the U.S. Department of Defense Armed Forces Health Surveillance Center-Global Program: Review of 2009 Accomplishments

Science.gov (United States)

2011-03-04

Vector borne infections (VBIs) such as malaria, dengue fever, yellow fever, scrub typhus , and plague comprise a significant proportion of the global...a VBI: scrub typhus (19), murine typhus (three), Japanese encephalitis (JE) (two), primary dengue infection (12), secondary dengue infection (nine...prioritized by GSRI, half are VBIs (malaria, dengue fever, Rift Valley fever, Chikungunya, CCHF, sandfly fever, O’nyong-nyong, Sindbis virus, scrub typhus

[Analysis of clinical characteristics of the 12 cases of neonatal dengue fever in Guangzhou in 2014 and literatures review].

Science.gov (United States)

Tan, Limei; Wang, Junping; Zeng, Fansen; Zhang, Yong; Fang, Chunxiao; Nie, Chuan; Xu, Yi; Yang, Jie

2015-12-01

To explore the clinical manifestations and laboratory examination characteristics of neonatal dengue fever. A retrospective analysis of 12 cases of neonatal dengue fever treated in the Guangdong Women and Children's Hospital and Guangzhou Women and Children's Medical Center was conducted, and related literature was reviewed. Twelve cases of neonatal dengue fever included 9 males and 3 females; their age was 30 min after birth to 29 d, the age of onset was 30 min-24 d. (1) CLINICAL FEATURES: fever was present in 11 cases, rash in 6 cases, bleeding in 1 case, jaundice in 5 cases, cough in 1 case, coagulopathy in 2 cases. (2) Mothers' perinatal conditions: 7 mothers were confirmed to have dengue fever, 2 mothers had suspected dengue fever, and in 3 mothers the dengue fever was excluded. Eight mothers prenatally had fever. (3) LABORATORY TESTS: Thrombocytopenia was found in 11 cases (19×10(9)-156×10(9)/L), activated partial thromboplastin time prolonged in 11 cases (44.0-89.8 s), fibrinogen decreased in 5 cases (1.17-3.02 g/L), aspartate aminotransferase (AST) increased in 5 cases (28-78 U/L), creatine kinase (CK-MB) increased in 4 cases (13-86 U/L), hypokalemia in 1 case (2.8-5.1 mmol/L ), C- reactive protein (CRP) increased in 6 cases (0.04-46.05 mg/L). (4) Treatment and prognosis: platelet transfusion was used in 2 cases, anti-infective therapy was given to 6 cases, intravenous gamma globulin treatment was used in 5 cases, hospitalization was 4-17 d, 10 cases were cured, 2 cases were discharged after condition was improved. Literature search was performed with "neonatal dengue" as keywords at Wanfang, Weipu, and CNKI, no relevant reports were found. Pubmed search was done with "neonatal dengue" and "case report" as keywords, 15 reports were retrieved during 1990 and 2014, which reported 30 cases, all acquired the disease via vertical transmission; the main clinical manifestations were fever, rash, petechiae, anemia, jaundice, tachycardia, and hepatomegaly

Oropouche Fever: A Review.

Science.gov (United States)

Sakkas, Hercules; Bozidis, Petros; Franks, Ashley; Papadopoulou, Chrissanthy

2018-04-04

Oropouche fever is an emerging zoonotic disease caused by Oropouche virus (OROV), an arthropod transmitted Orthobunyavirus circulating in South and Central America. During the last 60 years, more than 30 epidemics and over half a million clinical cases attributed to OROV infection have been reported in Brazil, Peru, Panama, Trinidad and Tobago. OROV fever is considered the second most frequent arboviral febrile disease in Brazil after dengue fever. OROV is transmitted through both urban and sylvatic transmission cycles, with the primary vector in the urban cycle being the anthropophilic biting midge Culicoides paraensis . Currently, there is no evidence of direct human-to-human OROV transmission. OROV fever is usually either undiagnosed due to its mild, self-limited manifestations or misdiagnosed because its clinical characteristics are similar to dengue, chikungunya, Zika and yellow fever, including malaria as well. At present, there is no specific antiviral treatment, and in the absence of a vaccine for effective prophylaxis of human populations in endemic areas, the disease prevention relies solely on vector control strategies and personal protection measures. OROV fever is considered to have the potential to spread across the American continent and under favorable climatic conditions may expand its geographic distribution to other continents. In view of OROV's emergence, increased interest for formerly neglected tropical diseases and within the One Health concept, the existing knowledge and gaps of knowledge on OROV fever are reviewed.

Prevalence of undifferentiated fever in adults of Rawalpindi having primary dengue fever

International Nuclear Information System (INIS)

Zafar, H.; Hayyat, A.; Akhtar, N.

2013-01-01

The objectives of the study were to highlight early subclinical presentation of dengue viral infection (DVI) as an undifferentiated febrile illness. The descriptive cross-sectional study was carried out at Microbiology Department, Rawalpindi Medical College from March to September 2009. Stratified random sampling was used to select subjects from various urban and rural areas of Rawalpindi, and Serum IgG anti-dengue antibodies were detected by using 3rd generation enzyme-linked immunosorbent assay (ELISA). Out of the total 240 subjects, 69 (28.75%) were found to be positive for anti-dengue IgG antibodies. Of the positive cases, 41 (59.4%) - comprising 31 (44.9%) urban residents - and 10 (14.4%) rural residents presented with a previous history of undifferentiated fever (p<0.05). It was concluded that primary DVI can present as subclinical form in healthy population residing in rural and urban areas of Rawalpindi, which is an alarming situation indicating the spread of disease in the study area. (author)

CLINICAL PROFILE OF DENGUE FEVER IN KANYAKUMARI GOVERNMENT MEDICAL COLLEGE- A STUDY FROM KANYAKUMARI, INDIA

Directory of Open Access Journals (Sweden)

Brinda J

2017-01-01

Full Text Available BACKGROUND Dengue infection is viral infection with different clinical presentation. This study was conducted in Kanyakumari Government Medical College Hospital, Asaripallam, Tamil Nadu, to study the various clinical profile and polyserositis involvement in dengue. MATERIALS AND METHODS The clinical profile and polyserositis involvement in dengue infection were determined by the retrospective study of all dengue infection in Kanyakumari Government Medical College Hospital, Asaripallam, Nagercoil, Tamilnadu. It was a retrospective study. All probable cases that had high-grade fever, lymphadenopathy, hepatomegaly, features of hock or haemorrhage and so forth and were admitted with provisional diagnosis of dengue fever were taken into account. All patients with positive dengue tests, either NS1 antigen, IgM, IgG antibody rapid serological test kit or ELISA were taken into the study group. As the duration of history of fever might be fallacious, the patients were subjected to all three serological tests. Patients who were positive for malaria, meningitis and enteric fever were excluded from the study. The whole number of patients included in our study was 40 (=40. RESULTS In this study, it was found that the bleeding manifestation had no correlation with thrombocytopenia, hepatomegaly and raised SGOT. All 40 patients had fever and they were treated with antipyretics (paracetamol in appropriate doses. Patients who presented with warning signs and stable vital signs were initially encouraged to take oral fluids; if they were not tolerated, intravenous fluids were started according to the WHO guidelines. CONCLUSION Dengue is an important arboviral infection in tropical countries. 1 Global incidence of dengue fever has increased dramatically in the recent decades. There are very few studies based on the revised new dengue classification. In our study, the total number of cases analysed was 40, out of which 28 (70% were categorised as cases of non

Dengue viral infections

OpenAIRE

Malavige, G; Fernando, S; Fernando, D; Seneviratne, S

2004-01-01

Dengue viral infections are one of the most important mosquito borne diseases in the world. They may be asymptomatic or may give rise to undifferentiated fever, dengue fever, dengue haemorrhagic fever (DHF), or dengue shock syndrome. Annually, 100 million cases of dengue fever and half a million cases of DHF occur worldwide. Ninety percent of DHF subjects are children less than 15 years of age. At present, dengue is endemic in 112 countries in the world. No vaccine is available for preventing...

Clinical and laboratory profile of dengue fever patients admitted in combined military hospital rawalpindi in year 2015

International Nuclear Information System (INIS)

Rehman, M. M. U.; Zakaria, M.; Mustafvi, S. A.

2017-01-01

Objective: The purpose of this study was to determine the pattern of clinical presentations, haematological and biochemical abnormalities, and outcome of dengue fever patients admitted in Combined Military Hospital (CMH) Rawalpindi in year 2015. Study Design: A descriptive cross sectional study. Place and Duration of Study: Department of Medicine, CMH Rawalpindi, from January 2015 to December 2015. Material and Methods: Patients meeting the inclusion criteria were admitted at CMH Rawalpindi and blood serology was done to confirm the diagnosis of dengue fever. Cases with positive dengue serology were included in the study. Clinical symptoms, signs, investigations and outcome of these patients were recorded on a proforma. Blood samples were taken for analysis. Chest X-Ray and ultrasound abdomen were done on required basis. Results: Out of forty confirmed cases of dengue fever, there were 25 (62.5 percent) males and 15 (37.5 percent) females. Mean age was 40 years. There were 39 cases (97.5 percent) of dengue fever and one case (2.5 percent) of dengue shock syndrome.There was no case of dengue haemorrhagic syndrome. Maximum cases were seen in the month of October 2015.The clinical features noted were: headache and myalgias 62.5 percent, chills and rigors 57.5 percent, retro-orbital pain 42.5 percent, vomiting 35.0 percent, pruritus 27 percent, skin rash 20 percent, abdominal pain 20 percent, diarrhoea 10 percent, bleeding 2.5 percent, ascites and pleural effusion 2.5 percent, and hepatomegaly 15 percent. The laboratory findings were: leucopenia 85 percent and thrombocytopenia 92.5 percent. Serum alanine transaminase (ALT), urea, and creatinine were raised in 30 percent, 2.5 percent and 7.5 percent cases respectively. Mortality was 2.5 percent. Conclusion: This study showed that patients admitted to CMH hospital had a milder presentation of dengue fever in the year 2015. (author)

Nationwide study of factors associated with public's willingness to use home self-test kit for dengue fever in Malaysia.

Science.gov (United States)

Wong, Li Ping; Atefi, Narges; AbuBakar, Sazaly

2016-08-12

As there is no specific treatment for dengue, early detection and access to proper treatment may lower dengue fatality. Therefore, having new techniques for the early detection of dengue fever, such as the use of dengue test kit, is vitally important. The aims of the study were: 1) identify factors associated with acceptance of a home self-test kit for dengue fever if the dengue test is available to the public and 2) find out the characteristics of the test kits that influence the use of the dengue test kit. A national telephone survey was carried out with 2,512 individuals of the Malaysian public aged 18-60 years old. Individuals were contacted by random digit dialling covering the whole of Malaysia from February 2012 to June 2013. From 2,512 participants, 6.1 % reported to have heard of the availability of the dengue home test kit and of these, 44.8 % expressed their intention to use the test kit if it was available. Multivariate logistic regressions indicated that participants with primary (OR: 0.65; 95 % CI: 0.43-0.89; p = 0.02, vs. tertiary educational level) and secondary educational levels (OR: 0.73; 95 % CI: 0.57-0.90; p = 0.01, vs. tertiary educational level) were less likely than participants with a tertiary educational level to use a home self-testing dengue kit for dengue if the kit was available. Participants with lower perceived barriers to dengue prevention (level of barriers 0-5) were less likely (OR: 0.67, 95 % CI: 0.53-0.85, p dengue kit for dengue if the kit was available compared to those with higher perceived barriers to dengue prevention (level of barriers 6-10). Participants with a lower total dengue fever knowledge score (range 0-22) were also less likely to use a home self-testing dengue kit for dengue if the kit was available (OR: 0.75; 95 % CI: 0.61-0.91, p = 0.001, vs. higher total dengue fever knowledge score) compared to those with a higher total dengue fever knowledge score (range 23-44). With response to

Lie integrable cases of the simplified multistrain/two-stream model for tuberculosis and dengue fever

Science.gov (United States)

Nucci, M. C.; Leach, P. G. L.

2007-09-01

We apply the techniques of Lie's symmetry analysis to a caricature of the simplified multistrain model of Castillo-Chavez and Feng [C. Castillo-Chavez, Z. Feng, To treat or not to treat: The case of tuberculosis, J. Math. Biol. 35 (1997) 629-656] for the transmission of tuberculosis and the coupled two-stream vector-based model of Feng and Velasco-Hernandez [Z. Feng, J.X. Velasco-Hernandez, Competitive exclusion in a vector-host model for the dengue fever, J. Math. Biol. 35 (1997) 523-544] to identify the combinations of parameters which lead to the existence of nontrivial symmetries. In particular we identify those combinations which lead to the possibility of the linearization of the system and provide the corresponding solutions. Many instances of additional symmetry are analyzed.

Municipality Level Simulations of Dengue Fever Incidence in Puerto Rico Using Ground Based and Remotely Sensed Climate Data

Science.gov (United States)

Quattrochi, Dale A.; Morin, Cory

2015-01-01

Dengue fever (DF) is caused by a virus transmitted between humans and Aedes genus mosquitoes through blood feeding. In recent decades incidence of the disease has drastically increased in the tropical Americas, culminating with the Pan American outbreak in 2010 which resulted in 1.7 million reported cases. In Puerto Rico dengue is endemic, however, there is significant inter-annual, intraannual, and spatial variability in case loads. Variability in climate and the environment, herd immunity and virus genetics, and demographic characteristics may all contribute to differing patterns of transmission both spatially and temporally. Knowledge of climate influences on dengue incidence could facilitate development of early warning systems allowing public health workers to implement appropriate transmission intervention strategies. In this study, we simulate dengue incidence in several municipalities in Puerto Rico using population and meteorological data derived from ground based stations and remote sensing instruments. This data was used to drive a process based model of vector population development and virus transmission. Model parameter values for container composition, vector characteristics, and incubation period were chosen by employing a Monte Carlo approach. Multiple simulations were performed for each municipality and the results were compared with reported dengue cases. The best performing simulations were retained and their parameter values and meteorological input were compared between years and municipalities. Parameter values varied by municipality and year illustrating the complexity and sensitivity of the disease system. Local characteristics including the natural and built environment impact transmission dynamics and produce varying responses to meteorological conditions.

Online platform for applying space–time scan statistics for prospectively detecting emerging hot spots of dengue fever

Directory of Open Access Journals (Sweden)

Chien-Chou Chen

2016-11-01

Full Text Available Abstract Background Cases of dengue fever have increased in areas of Southeast Asia in recent years. Taiwan hit a record-high 42,856 cases in 2015, with the majority in southern Tainan and Kaohsiung Cities. Leveraging spatial statistics and geo-visualization techniques, we aim to design an online analytical tool for local public health workers to prospectively identify ongoing hot spots of dengue fever weekly at the village level. Methods A total of 57,516 confirmed cases of dengue fever in 2014 and 2015 were obtained from the Taiwan Centers for Disease Control (TCDC. Incorporating demographic information as covariates with cumulative cases (365 days in a discrete Poisson model, we iteratively applied space–time scan statistics by SaTScan software to detect the currently active cluster of dengue fever (reported as relative risk in each village of Tainan and Kaohsiung every week. A village with a relative risk >1 and p value <0.05 was identified as a dengue-epidemic area. Assuming an ongoing transmission might continuously spread for two consecutive weeks, we estimated the sensitivity and specificity for detecting outbreaks by comparing the scan-based classification (dengue-epidemic vs. dengue-free village with the true cumulative case numbers from the TCDC’s surveillance statistics. Results Among the 1648 villages in Tainan and Kaohsiung, the overall sensitivity for detecting outbreaks increases as case numbers grow in a total of 92 weekly simulations. The specificity for detecting outbreaks behaves inversely, compared to the sensitivity. On average, the mean sensitivity and specificity of 2-week hot spot detection were 0.615 and 0.891 respectively (p value <0.001 for the covariate adjustment model, as the maximum spatial and temporal windows were specified as 50% of the total population at risk and 28 days. Dengue-epidemic villages were visualized and explored in an interactive map. Conclusions We designed an online analytical tool for

Genetic differentiation in populations of Aedes aegypti (Diptera, Culicidae dengue vector from the Brazilian state of Maranhão

Directory of Open Access Journals (Sweden)

Andrelina Alves de Sousa

2017-01-01

Full Text Available Aedes (Stegomyia aegypti is the vector responsible for the transmission of the viruses that cause zika, yellow and chikungunya fevers, the four dengue fever serotypes (DENV – 1, 2, 3, 4, and hemorrhagic dengue fever in tropical and subtropical regions around the world. The present study investigated the genetic differentiation of the 15 populations of this vector in the Brazilian state of Maranhão, based on the mitochondrial ND4 marker. A total of 177 sequences were obtained for Aedes aegypti, with a fragment of 337 bps, 15 haplotypes, 15 polymorphics sites, haplotype diversity of h = 0.6938, and nucleotide diversity of π = 0.01486. The neutrality tests (D and Fs were not significant. The AMOVA revealed that most of the variation (58.47% was found within populations, with FST = 0.41533 (p < 0.05. Possible isolation by distance was tested and a significant correlation coefficient (r = 0.3486; p = 0.0040 was found using the Mantel test. The phylogenetic relationships among the 15 haplotypes indicated the existence of two distinct clades. This finding, together with the population parameters, was consistent with a pattern of genetic structuring that underpinned the genetic differentiation of the study populations in Maranhão, and was characterized by the presence of distinct lineages of Aedes aegypti. Keywords: Gene flow, Mitochondrial DNA, ND4

Spatial-temporal analysis of dengue deaths: identifying social vulnerabilities

Directory of Open Access Journals (Sweden)

Maria do Socorro da Silva

Full Text Available Abstract: INTRODUCTION Currently, dengue fever, chikungunya fever, and zika virus represent serious public health issues in Brazil, despite efforts to control the vector, the Aedes aegypti mosquito. METHODS: This was a descriptive and ecological study of dengue deaths occurring from 2002 to 2013 in São Luis, Maranhão, Brazil. Geoprocessing software was used to draw maps, linking the geo-referenced deaths with urban/social data at census tract level. RESULTS: There were 74 deaths, concentrated in areas of social vulnerability. CONCLUSIONS: The use of geo-technology tools pointed to a concentration of dengue deaths in specific intra-urban areas.

Management of symptomatic thrombocytopenia associated with dengue haemorrhagic fever

International Nuclear Information System (INIS)

Jameel, T.; Saleem, I.U.; Mehmood, K.; Tanvir, I.; Saadia, A.

2010-01-01

Introduction: Immune - mediated destruction of platelets is thought to be the mechanism of thrombocytopenia seen after the viraemic phase of dengue haemorrhagic fever (DHF). Immuno - suppressants such as steroids, immune globulin and Anti D immune globulin are effective in the treatment of this type of immune thrombocytopenic purpura. Objective: To evaluate the efficacy of oral Prednisolone in the rate of resolution of thrombocytopenia and monitoring of complications in patients recovering from Dengue haemorrhagic fever. Method: A controlled study was carried out on diagnosed cases Dengue haemorrhagic patients presenting with sever thrombocytopenia and symptoms like confluent ecchymosis, epistaxis and purpuric rashes. In study was conducted in Ittefaq hospital (trust) Lahore, during the period of October to December 2008. Treatment group received steroids in two forms i.e. first line therapy prednisolone (1 mg / kg) orally or as second line therapy of initial I/V high dose (prednisolone) in pulse doses i.e. 40 mg / bd for four days and later oral prednisolone as in first line therapy with omeprazole 20 mg / bd in addition to standard treatment. Control group received standard supportive care only. Results: A total of 341 suspected patients were admitted in hospital. Serological diagnosis was confirmed in 166 patients. CBC revealed platelet count . 100 x 109 / l in 106 patients. A group of symptomatic febrile patients have platelet count < 20 x 109 / l was selected for therapeutic intervention. first line therapy (oral prednisolone was stated in 43 patients. In Fourteen patients second line therapy (high dose dexamethasone pulse) therapy was instituted. Seven of them attained complete response whereas two patients achieved partial response. Four patients were shifted to Anti D therapy. Three deaths occurred during our study. Rest of all the patients improved and were discharged in due course of time. Conclusion: This small scale preliminary study shows promising

Ongoing outbreak of dengue type 1 in the Autonomous Region of Madeira, Portugal: preliminary report.

Science.gov (United States)

Sousa, C A; Clairouin, M; Seixas, G; Viveiros, B; Novo, M T; Silva, A C; Escoval, M T; Economopoulou, A

2012-12-06

Following the identification of two autochthonous cases of dengue type 1 on 3 October 2012, an outbreak of dengue fever has been reported in Madeira, Portugal. As of 25 November, 1,891 cases have been detected on the island where the vector Aedes aegypti had been established in some areas since 2005. This event represents the first epidemic of dengue fever in Europe since 1928 and concerted control measures have been initiated by local health authorities.

Blood banking e Dengue fever

OpenAIRE

Ramos, Estácio F.

2008-01-01

Dengue is an endemic/epidemic arboviral disease with a variable symptomatic benign course, but potentially fatal. Once in an inhabited area, the disease will exist forever, with the best achievement being to keep vectors suppressed and the disease under control. Tiger mosquitoes (aedes aegypti, aedes albopictus) are active breeders and urban hunters, becoming resistant to pesticides. Global warming and population growth are propelling the disease worldwide at tropical and subtropical regions,...

Retinoids, race and the pathogenesis of dengue hemorrhagic fever.

Science.gov (United States)

Mawson, Anthony R

2013-12-01

Dengue hemorrhagic fever (DHF) is the most significant mosquito-borne viral disease worldwide in terms of illness, mortality and economic cost, but the pathogenesis of DHF is not well understood and there is no specific treatment or vaccine. Based on evidence of liver involvement, it is proposed that dengue virus and retinoids interact to cause cholestatic liver damage, resulting in the spillage of stored retinoids into the circulation and in an endogenous form of hypervitaminosisis A manifested by the signs and symptoms of the disease, including: fever, severe joint and bone pain, capillary leakage, thrombocytopenia, headache, and gastrointestinal symptoms. While retinoids in low concentration are essential for numerous biological functions, they are prooxidant, cytotoxic, mutagenic and teratogenic in higher concentration, especially when unbound to protein, and an endogenous form of vitamin A intoxication is recognized in cholestasis. The model tentatively explains the observations that 1) repeat infections are more severe than initial dengue virus infections; 2) the incidence of denue has increased dramatically worldwide in recent decades; 3) DHF is less prevalent in people of African ancestry than those of other racial backgrounds; and 4) infants are protected from dengue. The retinoid toxicity hypothesis of DHF predicts the co-existence of low serum concentrations of retinol coupled with high concentrations of retinoic acid and an increased percentage of retinyl esters to total vitamin A. Subject to such tests, it may be possible to treat DHF effectively using drugs that target the metabolism and expression of retinoids. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Germ line transformation of the yellow fever mosquito, Aedes aegypti, mediated by transpositional insertion of a piggyBac vector.

Science.gov (United States)

Lobo, N F; Hua-Van, A; Li, X; Nolen, B M; Fraser, M J

2002-04-01

Mosquito-vectored diseases such as yellow fever and dengue fever continue to have a substantial impact on human populations world-wide. Novel strategies for control of these mosquito vectored diseases can arise through the development of reliable systems for genetic manipulation of the insect vector. A piggyBac vector marked with the Drosophila melanogaster cinnabar (cn) gene was used to transform the white-eyed khw strain of Aedes aegypti. Microinjection of preblastoderm embryos resulted in four families of cinnabar transformed insects. An overall transformation frequency of 4%, with a range of 0% to as high as 13% for individual experiments, was achieved when using a heat-shock induced transposase providing helper plasmid. Southern hybridizations indicated multiple insertion events in three of four transgenic lines, while the presence of duplicated target TTAA sites at either ends of individual insertions confirmed characteristic piggyBac transposition events in these three transgenic lines. The transgenic phenotype has remained stable for more than twenty generations. The transformations effected using the piggyBac element establish the potential of this element as a germ-line transformation vector for Aedine mosquitoes.

Strain Variation in the Transcriptome of the Dengue Fever Vector, Aedes aegypti.

Science.gov (United States)

Bonizzoni, Mariangela; Dunn, W Augustine; Campbell, Corey L; Olson, Ken E; Marinotti, Osvaldo; James, Anthony A

2012-01-01

Studies of transcriptome dynamics provide a basis for understanding functional elements of the genome and the complexity of gene regulation. The dengue vector mosquito, Aedes aegypti, exhibits great adaptability to diverse ecological conditions, is phenotypically polymorphic, and shows variation in vectorial capacity to arboviruses. Previous genome sequencing showed richness in repetitive DNA and transposable elements that can contribute to genome plasticity. Population genetic studies revealed a varying degree of worldwide genetic polymorphism. However, the extent of functional genetic polymorphism across strains is unknown. The transcriptomes of three Ae. aegypti strains, Chetumal (CTM), Rexville D-Puerto Rico (Rex-D) and Liverpool (LVP), were compared. CTM is more susceptible than Rex- D to infection by dengue virus serotype 2. A total of 4188 transcripts exhibit either no or small variation (<2-fold) among sugar-fed samples of the three strains and between sugar- and blood-fed samples within each strain, corresponding most likely to genes encoding products necessary for vital functions. Transcripts enriched in blood-fed mosquitoes encode proteins associated with catalytic activities, molecular transport, metabolism of lipids, carbohydrates and amino acids, and functions related to blood digestion and the progression of the gonotropic cycle. Significant qualitative and quantitative differences were found in individual transcripts among strains including differential representation of paralogous gene products. The majority of immunity-associated transcripts decreased in accumulation after a bloodmeal and the results are discussed in relation to the different susceptibility of CTM and Rex-D mosquitoes to DENV2 infection.

Evolving herbal formulations in management of dengue fever.

Science.gov (United States)

Singh, Pawan Kumar; Rawat, Pooja

Dengue is endemic in more than 100 countries and it is estimated that annually above 390 million infections occur globally. During the period between 1996-2015, a massive increase of more than 500 per cent has been recorded in number of dengue cases reported in India. Till date, there are no specific globally accepted treatments for dengue fever in any system of medicine. Dengue does not cause very high mortality if properly handled and is currently being managed by clinicians through various adjuvant and alternative therapeutic options. Various plant based preparations have been used in different parts of India for combating dengue and are simultaneously also being scientifically validated by researchers. However, number of such scientific validation studies on phytomedicines are very less in India. Out of twenty-two plants reported against dengue, only four have been studied scientifically. Azadirachta indica, Carica papaya, Hippophae rhamnoides and Cissampelos pareira extracts were found effective and demonstrated improvement in clinical symptoms and direct inhibitory effect on dengue virus. C. papaya clinical trial showed increase in platelet count and faster recovery. These plants may be explored further as probable candidates for drug discovery against dengue. There is a need to search more such herbal formulations, which are being practiced at local level, document properly and validate them scientifically to confirm efficacy, mechanistic action and safety, before use. The herbal formulations being used by communities are the low hanging fruits which may provide alternative or adjuvant therapy if proper validation, value addition and product development steps are followed. This paper aims to review the recent status of dengue cases, deaths and evolving curative herbal solutions adapted and reported from India to combat the disease. Copyright © 2017 Transdisciplinary University, Bangalore and World Ayurveda Foundation. Published by Elsevier B.V. All rights

Environmental data analysis and remote sensing for early detection of dengue and malaria

Science.gov (United States)

Rahman, Md Z.; Roytman, Leonid; Kadik, Abdelhamid; Rosy, Dilara A.

2014-06-01

Malaria and dengue fever are the two most common mosquito-transmitted diseases, leading to millions of serious illnesses and deaths each year. Because the mosquito vectors are sensitive to environmental conditions such as temperature, precipitation, and humidity, it is possible to map areas currently or imminently at high risk for disease outbreaks using satellite remote sensing. In this paper we propose the development of an operational geospatial system for malaria and dengue fever early warning; this can be done by bringing together geographic information system (GIS) tools, artificial neural networks (ANN) for efficient pattern recognition, the best available ground-based epidemiological and vector ecology data, and current satellite remote sensing capabilities. We use Vegetation Health Indices (VHI) derived from visible and infrared radiances measured by satellite-mounted Advanced Very High Resolution Radiometers (AVHRR) and available weekly at 4-km resolution as one predictor of malaria and dengue fever risk in Bangladesh. As a study area, we focus on Bangladesh where malaria and dengue fever are serious public health threats. The technology developed will, however, be largely portable to other countries in the world and applicable to other disease threats. A malaria and dengue fever early warning system will be a boon to international public health, enabling resources to be focused where they will do the most good for stopping pandemics, and will be an invaluable decision support tool for national security assessment and potential troop deployment in regions susceptible to disease outbreaks.

Vector competence of Aedes albopictus and Aedes aegypti (Diptera: Culicidae) for the DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus in Fujian, China.

Science.gov (United States)

Guo, Xiao-Xia; Li, Chun-Xiao; Zhang, Ying-Mei; Xing, Dan; Dong, Yan-De; Zhang, Heng-Duan; Qin, Cheng-Feng; Zhao, Tong-Yan

2016-09-01

Dengue is an acute, emerging, infectious disease transmitted by Aedes mosquitoes that has become a serious global public health problem. The DEN2-FJ10 and DEN2-FJ11 strains of the dengue 2 virus were originally isolated from the serum of a patient with dengue fever in Fujian Province, China, in 1999. Our data provide the first assessment of the vector competence of Aedes mosquitoes with respect to the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus. There were significant differences in the replication rates of these two viral strains in Aedes albopictus and Aedes aegypti (P0.05). In summary, our results indicate that Ae. albopictus and Ae. aegypti mosquitoes are moderately competent vectors of the DEN2-FJ10 and DEN2-FJ11 strains of the dengue virus and provide the first evidence of the effect of these two viral strains on the vector competence of mosquitoes in China. Copyright © 2016 Elsevier B.V. All rights reserved.

Manifestações mucocutâneas da dengue Mucocutaneous manifestations of dengue

Directory of Open Access Journals (Sweden)

Omar Lupi

2007-08-01

Full Text Available Dengue é doença viral sistêmica que ocorre de forma epidêmica em áreas tropicais e subtropicais da Ásia, Américas e África. O vírus da dengue pertence ao gênero Flavivirus e à família Flaviviridae (arbovírus do grupo B. Aedes aegypti é o principal vetor e verdadeiro reservatório. A febre na dengue clássica persiste por período de dois a cinco dias com cefaléia intensa, mialgia, artralgia e dor retro-orbital. Alterações cutâneas incluem diversos achados como erupção morbiliforme que pode ser pruriginosa e que gera descamação residual, algumas manifestações hemorrágicas discretas como epistaxe, petéquias e sangramento gengival. Extravasamento capilar de plasma é responsável pela hemoconcentração e trombocitopenia observadas e que caracterizam a dengue hemorrágica. Manifestações cutâneas da dengue hemorrágica incluem lesões hemorrágicas disseminadas como petéquias e equimoses, mas também instabilidade hemodinâmica com pulso filiforme, pressão arterial convergente, extremidades frias, confusão mental e choque.Dengue fever is a systemic viral disease that occurs epidemically in tropical and subtropical regions of Asia, Americas and Africa. The dengue virus belongs to the genus Flavivirus of the family Flaviviridae (group B arbovirus. Aedes aegypti is the major vector and the true reservoir for the virus. Classic dengue fever lasts for two-five days, with severe headache, intense myalgia, arthralgia and retro-orbital pain. Cutaneous alterations include several findings such as a diffuse morbilliform rash that may be pruritic and heals with desquamation, and minor bleeding phenomena such as epistaxis, petechiae, and gingival bleeding. Diffuse capillary leakage of plasma is responsible for the hemoconcentration and thrombocytopenia that characterize dengue hemorrhagic fever. Cutaneous manifestations of dengue hemorrhagic fever include many disseminated hemorrhagic lesions such as petechiae and ecchymoses, but

Exploring the molecular basis of insecticide resistance in the dengue vector Aedes aegypti: a case study in Martinique Island (French West Indies).

Science.gov (United States)

Marcombe, Sébastien; Poupardin, Rodolphe; Darriet, Frederic; Reynaud, Stéphane; Bonnet, Julien; Strode, Clare; Brengues, Cecile; Yébakima, André; Ranson, Hilary; Corbel, Vincent; David, Jean-Philippe

2009-10-26

The yellow fever mosquito Aedes aegypti is a major vector of dengue and hemorrhagic fevers, causing up to 100 million dengue infections every year. As there is still no medicine and efficient vaccine available, vector control largely based on insecticide treatments remains the only method to reduce dengue virus transmission. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides. Resistance of Ae. aegypti to chemical insecticides has been reported worldwide and the underlying molecular mechanisms, including the identification of enzymes involved in insecticide detoxification are not completely understood. The present paper investigates the molecular basis of insecticide resistance in a population of Ae. aegypti collected in Martinique (French West Indies). Bioassays with insecticides on adults and larvae revealed high levels of resistance to organophosphate and pyrethroid insecticides. Molecular screening for common insecticide target-site mutations showed a high frequency (71%) of the sodium channel 'knock down resistance' (kdr) mutation. Exposing mosquitoes to detoxification enzymes inhibitors prior to bioassays induced a significant increased susceptibility of mosquitoes to insecticides, revealing the presence of metabolic-based resistance mechanisms. This trend was biochemically confirmed by significant elevated activities of cytochrome P450 monooxygenases, glutathione S-transferases and carboxylesterases at both larval and adult stages. Utilization of the microarray Aedes Detox Chip containing probes for all members of detoxification and other insecticide resistance-related enzymes revealed the significant constitutive over-transcription of multiple detoxification genes at both larval and adult stages. The over-transcription of detoxification genes in the resistant strain was confirmed by using real-time quantitative RT-PCR. These results suggest that the high level of

Clinical significance of skin rash in dengue fever: A focus on discomfort, complications, and disease outcome.

Science.gov (United States)

Huang, Hsin-Wei; Tseng, Han-Chi; Lee, Chih-Hung; Chuang, Hung-Yi; Lin, Shang-Hung

2016-07-01

To assess whether the cutaneous features in patients with dengue fever are associated with abnormal blood biochemistry, complications, and poor disease outcome. Forty five patients with dengue fever were identified at a medical center in Kaohsiung, Taiwan, from September to November 2014. All cases were exclusively caused by type 1 dengue virus. Patients were classified into two groups, based on the presence or absence of skin rash, and their rash was subclassified into maculopapular, morbilliform, and petechial types. Clinical symptoms, laboratory data, disease outcome, and complications were compared between the two groups. Thirty two patients with dengue fever developed skin rash (SP group, n = 32) while the rest of 13 did not (SN group, n = 13). The patient numbers in the maculopapular, morbilliform, and petechial group were 4, 21, and 7, respectively. The SP group was younger (P = 0.001), experienced more pruritus (P = 0.008) and more swollen palms/soles (P = 0.015) than the SN group. However, the SN group had greater genital mucosa involvement (P = 0.008), higher platelet transfusion rate (P = 0.003), and lower hemoglobin and hematocrit levels (P = 0.030) than the SP group. Patients with morbilliform lesions had a higher incidence of palm/sole swelling, less genital mucosal involvement, and a lower platelet transfusion rate than did patients with maculopapular or petechial lesions. Cutaneous manifestations provide an important clue to dengue fever. In patients with dengue fever, those with skin rash tend to have itching and swelling of the palms/soles, however, those without skin rash tend to have more complications and poor disease outcomes. Copyright © 2016 Hainan Medical College. Production and hosting by Elsevier B.V. All rights reserved.

Oropouche Fever: A Review

Directory of Open Access Journals (Sweden)

Hercules Sakkas

2018-04-01

Full Text Available Oropouche fever is an emerging zoonotic disease caused by Oropouche virus (OROV, an arthropod transmitted Orthobunyavirus circulating in South and Central America. During the last 60 years, more than 30 epidemics and over half a million clinical cases attributed to OROV infection have been reported in Brazil, Peru, Panama, Trinidad and Tobago. OROV fever is considered the second most frequent arboviral febrile disease in Brazil after dengue fever. OROV is transmitted through both urban and sylvatic transmission cycles, with the primary vector in the urban cycle being the anthropophilic biting midge Culicoides paraensis. Currently, there is no evidence of direct human-to-human OROV transmission. OROV fever is usually either undiagnosed due to its mild, self-limited manifestations or misdiagnosed because its clinical characteristics are similar to dengue, chikungunya, Zika and yellow fever, including malaria as well. At present, there is no specific antiviral treatment, and in the absence of a vaccine for effective prophylaxis of human populations in endemic areas, the disease prevention relies solely on vector control strategies and personal protection measures. OROV fever is considered to have the potential to spread across the American continent and under favorable climatic conditions may expand its geographic distribution to other continents. In view of OROV’s emergence, increased interest for formerly neglected tropical diseases and within the One Health concept, the existing knowledge and gaps of knowledge on OROV fever are reviewed.

Dengue incidence in urban and rural Cambodia: results from population-based active fever surveillance, 2006-2008.

Directory of Open Access Journals (Sweden)

Sirenda Vong

Full Text Available BACKGROUND: Dengue vaccines are now in late-stage development, and evaluation and robust estimates of dengue disease burden are needed to facilitate further development and introduction. In Cambodia, the national dengue case-definition only allows reporting of children less than 16 years of age, and little is known about dengue burden in rural areas and among older persons. To estimate the true burden of dengue in the largest province of Cambodia, Kampong Cham, we conducted community-based active dengue fever surveillance among the 0-to-19-year age group in rural villages and urban areas during 2006-2008. METHODS AND FINDINGS: Active surveillance for febrile illness was conducted in 32 villages and 10 urban areas by mothers trained to use digital thermometers combined with weekly home visits to identify persons with fever. An investigation team visited families with febrile persons to obtain informed consent for participation in the follow-up study, which included collection of personal data and blood specimens. Dengue-related febrile illness was defined using molecular and serological testing of paired acute and convalescent blood samples. Over the three years of surveillance, 6,121 fever episodes were identified with 736 laboratory-confirmed dengue virus (DENV infections for incidences of 13.4-57.8/1,000 person-seasons. Average incidence was highest among children less than 7 years of age (41.1/1,000 person-seasons and lowest among the 16-to-19-year age group (11.3/1,000 person-seasons. The distribution of dengue was highly focal, with incidence rates in villages and urban areas ranging from 1.5-211.5/1,000 person-seasons (median 36.5. During a DENV-3 outbreak in 2007, rural areas were affected more than urban areas (incidence 71 vs. 17/1,000 person-seasons, p<0.001. CONCLUSION: The large-scale active surveillance study for dengue fever in Cambodia found a higher disease incidence than reported to the national surveillance system, particularly

First dengue haemorrhagic fever epidemic in the Americas, 1981: insights into the causative agent.

Science.gov (United States)

Rodriguez-Roche, Rosmari; Hinojosa, Yoandri; Guzman, Maria G

2014-12-01

Historical records describe a disease in North America that clinically resembled dengue haemorrhagic fever during the latter part of the slave-trading period. However, the dengue epidemic that occurred in Cuba in 1981 was the first laboratory-confirmed and clinically diagnosed outbreak of dengue haemorrhagic fever in the Americas. At that time, the presumed source of the dengue type 2 strain isolated during this epidemic was considered controversial, partly because of the limited sequence data and partly because the origin of the virus appeared to be southern Asia. Here, we present a molecular characterisation at the whole-genome level of the original strains isolated at different time points during the epidemic. Phylogenetic trees constructed using Bayesian methods indicated that 1981 Cuban strains group within the Asian 2 genotype. In addition, the study revealed that viral evolution occurred during the epidemic - a fact that could be related to the increasing severity from month to month. Moreover, the Cuban strains exhibited particular amino acid substitutions that differentiate them from the New Guinea C prototype strain as well as from dengue type 2 strains isolated globally.

Spectrum of Maternofetal Outcomes during Dengue Infection in Pregnancy: An Insight

Directory of Open Access Journals (Sweden)

Swati Sharma

2016-01-01

Full Text Available Dengue is a vector transmitted viral infection; tropical and subtropical countries see outbreaks of dengue each year. There is a paucity of literature on effects of dengue infection on pregnancy outcome and this prompted us to undertake a study for better understanding of pregnancy implications with dengue infection. Pregnant women admitted during the seasonal outbreak of dengue between September 2015 and October 2015 were studied and maternal and fetal outcomes in sixteen NS1Ag positive women were analysed. Out of sixteen women diagnosed with dengue fever, three had dengue shock syndrome (DSS and eight had dengue haemorrhagic fever (DHF. The most common obstetric complication seen in 43% of the cases was oligohydramnios. Bleeding manifestations occurred in seven women and there were three maternal deaths. Perinatal complications included three intrauterine deaths, six nursery admissions, and one neonatal death. Thus dengue infection was associated with high maternal and perinatal mortality. In view of poor obstetric outcomes, this viral infection warrants early admission and prompt management.

Dengue fever Potential Area at Pademangan Barat Sub District, North Jakarta

Directory of Open Access Journals (Sweden)

Tri E. B. Soesilo

2011-06-01

Full Text Available Dengue hemorrhagic fever is an infectious disease that contagious by Aedes aegypti mosquito’s bites. Anybody could infectious by this illness, without differentiate their sex, age, social status, and economic status as well. Nevertheless, at slum area, where mosquito’s larva is easy to find, the number of infectious people is presuming high. By using primary data and analyze with geography information system (GIS, the study found that the number of infectious people of dengue fever do not have any positive correlation with larva amount, that was monitored through clean water in the surrounding neighborhood area. The number of infectious people have correlation with the dirty areas that caused by the piling of used articles and inundate area. Gender and age do not have any influence with the number of infectious people.

Serum Metabolomics Reveals Serotonin as a Predictor of Severe Dengue in the Early Phase of Dengue Fever

Science.gov (United States)

Thein, Tun Linn; Fang, Jinling; Pang, Junxiong; Ooi, Eng Eong; Leo, Yee Sin; Ong, Choon Nam; Tannenbaum, Steven R.

2016-01-01

Effective triage of dengue patients early in the disease course for in- or out-patient management would be useful for optimal healthcare resource utilization while minimizing poor clinical outcome due to delayed intervention. Yet, early prognosis of severe dengue is hampered by the heterogeneity in clinical presentation and routine hematological and biochemical measurements in dengue patients that collectively correlates poorly with eventual clinical outcome. Herein, untargeted liquid-chromatography mass spectrometry metabolomics of serum from patients with dengue fever (DF) and dengue hemorrhagic fever (DHF) in the febrile phase (1.5) in the serum, among which are two products of tryptophan metabolism–serotonin and kynurenine. Serotonin, involved in platelet aggregation and activation decreased significantly, whereas kynurenine, an immunomodulator, increased significantly in patients with DHF, consistent with thrombocytopenia and immunopathology in severe dengue. To sensitively and accurately evaluate serotonin levels as prognostic biomarkers, we implemented stable-isotope dilution mass spectrometry and used convalescence samples as their own controls. DHF serotonin was significantly 1.98 fold lower in febrile compared to convalescence phase, and significantly 1.76 fold lower compared to DF in the febrile phase of illness. Thus, serotonin alone provided good prognostic utility (Area Under Curve, AUC of serotonin = 0.8). Additionally, immune mediators associated with DHF may further increase the predictive ability than just serotonin alone. Nine cytokines, including IFN-γ, IL-1β, IL-4, IL-8, G-CSF, MIP-1β, FGF basic, TNFα and RANTES were significantly different between DF and DHF, among which IFN-γ ranked top by multivariate statistics. Combining serotonin and IFN-γ improved the prognosis performance (AUC = 0.92, sensitivity = 77.8%, specificity = 95.8%), suggesting this duplex panel as accurate metrics for the early prognosis of DHF. PMID:27055163

Challenges in dengue fever in the elderly: atypical presentation and risk of severe dengue and hospital-acquired infection [corrected].

Directory of Open Access Journals (Sweden)

Emily K Rowe

2014-04-01

Full Text Available BACKGROUND/METHODS: To better understand dengue fever in the elderly, we compared clinical features, World Health Organization (WHO dengue classification and outcomes between adult (<60 and elderly (≥60 dengue patients. We explored the impact of co-morbidity and hospital-acquired infection (HAI on clinical outcomes in the elderly. All patients managed at the Communicable Disease Centre, Singapore, between 2005 and 2008 with positive dengue polymerase chain reaction (PCR or who fulfilled WHO 1997 or 2009 probable dengue criteria with positive dengue IgM were included. RESULTS: Of the 6989 cases, 295 (4.4% were elderly. PCR was positive in 29%. The elderly suffered more severe disease with more dengue haemorrhagic fever (DHF (29.2% vs. 21.4% and severe dengue (SD (20.3% vs. 14.6% (p<0.05. Classic dengue symptoms were more common in the adult group. The elderly were less likely to fulfill WHO 1997 (93.6% vs. 96.4% (p = 0.014, but not WHO 2009 probable dengue (75.3% vs. 71.5%. Time to dengue diagnosis was similar. There was no significant difference in the frequency of warning signs between the two groups, but the elderly were more likely to have hepatomegaly (p = 0.006 and malaise/lethargy (p = 0.033 while the adults had significantly more mucosal bleeding (p<0.001. Intensive care admission occurred in 15 and death in three, with no age difference. Notably, the elderly stayed in hospital longer (median 5 vs. 4 days, and suffered more pneumonia (3.8% vs. 0.7% and urinary infection (1.9% vs. 0.3% (p = 0.003. Predictors of excess length of stay were age (adjusted odds ratio [aOR] 2.01, 95% confidence interval [CI] 1.37-2.88, critical illness (aOR 5.13, 95%CI 2.59-9.75, HAI (aOR 12.06, 95%CI 7.39-19.9, Charlson score (aOR 6.9, 95%CI 2.02-22.56 and severe dengue (DHF/dengue shock syndrome/SD (aOR 2.24, 95%CI 1.83-2.74. CONCLUSION: Elderly dengue patients present atypically and are at higher risk of DHF, SD and HAI. Aside from dengue

Dengue Fever Seroprevalence and Risk Factors, Texas-Mexico Border, 2004

Centers for Disease Control (CDC) Podcasts

2007-11-01

Dengue fever is both endemic and underrecognized along a section of the southern Texas–Mexico border, and low income is a primary risk factor for infection. As part of a special section on Global Poverty and Human Development, Dr. Joan Marie Brunkard discusses a dengue seroprevalence survey in this region and what can be done to help prevent infection and to identify and treat those who are infected.  Created: 11/1/2007 by Emerging Infectious Diseases.   Date Released: 1/24/2008.

Climate change and the effects of dengue upon Australia: An analysis of health impacts and costs

International Nuclear Information System (INIS)

Newth, D; Gunasekera, D

2010-01-01

Projected regional warming and climate change analysis and health impact studies suggest that Australia is potentially vulnerable to increased occurrence of vector borne diseases such as dengue fever. Expansion of the dengue fever host, Aedes aegypti could potentially pose a significant public health risk. To manage such health risks, there is a growing need to focus on adaptive risk management strategies. In this paper, we combine analyses from climate, biophysical and economic models with a high resolution population model for disease spread, the EpiCast model to analyse the health impacts and costs of spread of dengue fever. We demonstrate the applicability of EpiCast as a decision support tool to evaluate mitigation strategies to manage the public health risks associated with shifts in the distribution of dengue fever in Australia.

Climate change and the effects of dengue upon Australia: An analysis of health impacts and costs

Energy Technology Data Exchange (ETDEWEB)

Newth, D; Gunasekera, D, E-mail: david.newth@csiro.a [CSIRO Centre for Complex Systems Science, CSIRO Marine and Atmospheric Research, CSIRO, GPO Box 3023, Canberra ACT 2601 (Australia)

2010-08-15

Projected regional warming and climate change analysis and health impact studies suggest that Australia is potentially vulnerable to increased occurrence of vector borne diseases such as dengue fever. Expansion of the dengue fever host, Aedes aegypti could potentially pose a significant public health risk. To manage such health risks, there is a growing need to focus on adaptive risk management strategies. In this paper, we combine analyses from climate, biophysical and economic models with a high resolution population model for disease spread, the EpiCast model to analyse the health impacts and costs of spread of dengue fever. We demonstrate the applicability of EpiCast as a decision support tool to evaluate mitigation strategies to manage the public health risks associated with shifts in the distribution of dengue fever in Australia.

Nationwide study of factors associated with public’s willingness to use home self-test kit for dengue fever in Malaysia

Directory of Open Access Journals (Sweden)

Li Ping Wong

2016-08-01

Full Text Available Abstract Background As there is no specific treatment for dengue, early detection and access to proper treatment may lower dengue fatality. Therefore, having new techniques for the early detection of dengue fever, such as the use of dengue test kit, is vitally important. The aims of the study were: 1 identify factors associated with acceptance of a home self-test kit for dengue fever if the dengue test is available to the public and 2 find out the characteristics of the test kits that influence the use of the dengue test kit. Methods A national telephone survey was carried out with 2,512 individuals of the Malaysian public aged 18–60 years old. Individuals were contacted by random digit dialling covering the whole of Malaysia from February 2012 to June 2013. Results From 2,512 participants, 6.1 % reported to have heard of the availability of the dengue home test kit and of these, 44.8 % expressed their intention to use the test kit if it was available. Multivariate logistic regressions indicated that participants with primary (OR: 0.65; 95 % CI: 0.43–0.89; p = 0.02, vs. tertiary educational level and secondary educational levels (OR: 0.73; 95 % CI: 0.57–0.90; p = 0.01, vs. tertiary educational level were less likely than participants with a tertiary educational level to use a home self-testing dengue kit for dengue if the kit was available. Participants with lower perceived barriers to dengue prevention (level of barriers 0–5 were less likely (OR: 0.67, 95 % CI: 0.53–0.85, p < 0.001, vs. higher perceived barriers to use a home self-testing dengue kit for dengue if the kit was available compared to those with higher perceived barriers to dengue prevention (level of barriers 6-10. Participants with a lower total dengue fever knowledge score (range 0–22 were also less likely to use a home self-testing dengue kit for dengue if the kit was available (OR: 0.75; 95 % CI: 0.61–0.91, p = 0.001, vs. higher total dengue

Social justice, climate change, and dengue.

Science.gov (United States)

Chang, Aileen Y; Fuller, Douglas O; Carrasquillo, Olveen; Beier, John C

2014-06-14

Climate change should be viewed fundamentally as an issue of global justice. Understanding the complex interplay of climatic and socioeconomic trends is imperative to protect human health and lessen the burden of diseases such as dengue fever. Dengue fever is rapidly expanding globally. Temperature, rainfall, and frequency of natural disasters, as well as non-climatic trends involving population growth and migration, urbanization, and international trade and travel, are expected to increase the prevalence of mosquito breeding sites, mosquito survival, the speed of mosquito reproduction, the speed of viral incubation, the distribution of dengue virus and its vectors, human migration patterns towards urban areas, and displacement after natural disasters. The burden of dengue disproportionately affects the poor due to increased environmental risk and decreased health care. Mobilization of social institutions is needed to improve the structural inequalities of poverty that predispose the poor to increased dengue fever infection and worse outcomes. This paper reviews the link between dengue and climatic factors as a starting point to developing a comprehensive understanding of how climate change affects dengue risk and how institutions can address the issues of social justice and dengue outbreaks that increasingly affect vulnerable urban populations. Copyright © 2014 Chang, Fuller, Carrasquillo, Beier. This is an open access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original author and source are credited.

Progress in the Identification of Dengue Virus Entry/Fusion Inhibitors

Directory of Open Access Journals (Sweden)

Carolina De La Guardia

2014-01-01

Full Text Available Dengue fever, a reemerging disease, is putting nearly 2.5 billion people at risk worldwide. The number of infections and the geographic extension of dengue fever infection have increased in the past decade. The disease is caused by the dengue virus, a flavivirus that uses mosquitos Aedes sp. as vectors. The disease has several clinical manifestations, from the mild cold-like illness to the more serious hemorrhagic dengue fever and dengue shock syndrome. Currently, there is no approved drug for the treatment of dengue disease or an effective vaccine to fight the virus. Therefore, the search for antivirals against dengue virus is an active field of research. As new possible receptors and biological pathways of the virus biology are discovered, new strategies are being undertaken to identify possible antiviral molecules. Several groups of researchers have targeted the initial step in the infection as a potential approach to interfere with the virus. The viral entry process is mediated by viral proteins and cellular receptor molecules that end up in the endocytosis of the virion, the fusion of both membranes, and the release of viral RNA in the cytoplasm. This review provides an overview of the targets and progress that has been made in the quest for dengue virus entry inhibitors.

Epidemic dengue and dengue hemorrhagic fever at the Texas-Mexico border: results of a household-based seroepidemiologic survey, December 2005.

Science.gov (United States)

Ramos, Mary M; Mohammed, Hamish; Zielinski-Gutierrez, Emily; Hayden, Mary H; Lopez, Jose Luis Robles; Fournier, Marta; Trujillo, Alfredo Rodríguez; Burton, Roy; Brunkard, Joan M; Anaya-Lopez, Luis; Banicki, Allison Abell; Morales, Pablo Kuri; Smith, Brian; Muñoz, Jorge L; Waterman, Stephen H

2008-03-01

A dengue-2 epidemic causing dengue hemorrhagic fever (DHF) occurred in the contiguous border cities of Matamoros, Tamaulipas (Mexico), and Brownsville, TX, in 2005. In December, we conducted a household-based epidemiologic survey to determine the incidence and seroprevalence of dengue infection among Matamoros and Brownsville residents and to identify risk factors associated with infection. Antibodies to dengue were measured in 273 individuals. The estimated incidence of recent dengue infection was 32% and 4% among Matamoros and Brownsville participants, respectively. The estimated prevalence of past dengue infection was 77% and 39% among Matamoros and Brownsville participants, respectively. The Breteau index was 28 in Matamoros and 16 in Brownsville, reflecting an abundant winter population of Aedes mosquitoes. Discarded waste tires and buckets were the two largest categories of infested containers found in both cities. Our results underscore the risk for epidemic dengue and DHF in the Texas-Mexico border region.

Dengue virus transovarial transmission by Aedes aegypti

Directory of Open Access Journals (Sweden)

Monica Dwi Hartanti

2016-02-01

Full Text Available Dengue is a disease that is caused by dengue virus and transmitted to humans through the bite of infected Aedes mosquitoes, especially Aedes aegypti. The disease is hyper-endemic in Southeast Asia, where a more severe form, dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS, is a major public health concern. The purpose of the present study was to find evidence of dengue virus transovarial transmision in local vectors in Jakarta. Fifteen Aedes larvae were collected in 2009 from two areas in Tebet subdistrict in South Jakarta, namely one area with the highest and one with the lowest DHF prevalence. All mosquitoes were reared inside two cages in the laboratory, eight mosquitoes in one cage and seven mosquitoes in another cage and given only sucrose solution as their food. The results showed that 20% of the mosquitoes were positive for dengue virus. Dengue virus detection with an immunohistochemical method demonstrated the occurrence of transovarial transmission in local DHF vectors in Tebet subdistrict. Transovarial dengue infection in Ae.aegypti larvae appeared to maintain or enhance epidemics. Further research is needed to investigate the relation of dengue virus transovarial transmission with DHF endemicity in Jakarta.

Dengue virus transovarial transmission by Aedes aegypti

Directory of Open Access Journals (Sweden)

Monica Dwi Hartanti

2010-08-01

Full Text Available Dengue is a disease that is caused by dengue virus and transmitted to humans through the bite of infected Aedes mosquitoes, especially Aedes aegypti. The disease is hyper-endemic in Southeast Asia, where a more severe form, dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS, is a major public health concern. The purpose of the present study was to find evidence of dengue virus transovarial transmision in local vectors in Jakarta. Fifteen Aedes larvae were collected in 2009 from two areas in Tebet subdistrict in South Jakarta, namely one area with the highest and one with the lowest DHF prevalence. All mosquitoes were reared inside two cages in the laboratory, eight mosquitoes in one cage and seven mosquitoes in another cage and given only sucrose solution as their food. The results showed that 20% of the mosquitoes were positive for dengue virus. Dengue virus detection with an immunohistochemical method demonstrated the occurrence of transovarial transmission in local DHF vectors in Tebet subdistrict. Transovarial dengue infection in Ae.aegypti larvae appeared to maintain or enhance epidemics. Further research is needed to investigate the relation of dengue virus transovarial transmission with DHF endemicity in Jakarta.

Dengue Fever in American Military Personnel in the Philippines: Clinical Observations on Hospitalized Patients during a 1984 Epidemic

Science.gov (United States)

1989-03-01

the mean maximum temperature was Hypotenson 15 (62.5) 102.0 + 1.3 F. A "saddle back" or dip- Rash (Non- Petechial ) 13 (54.2) hasic fever pattern was not...DENGUE FEVER IN AMERICAN MILITARY PERSONNEL IN THE PHILIPPINES: CLINICAL OBSERVATIONS ON HOSPITALIZED PATIENS DURING A 1984 EPIDEMIC C.G. Hayes, T.F...Accession Tr~I Jti ti DENGUE FEVER IN AMERICAN MILITARY PERSONNEL IN THE PHILIPPINES: CLINICAL OBSERVATIONS ON HOSPITALIZED PATIENTS DURING A 1984

The extinction of dengue through natural vulnerability of its vectors.

Directory of Open Access Journals (Sweden)

Craig R Williams

Full Text Available BACKGROUND: Dengue is the world's most important mosquito-borne viral illness. Successful future management of this disease requires an understanding of the population dynamics of the vector, especially in the context of changing climates. Our capacity to predict future dynamics is reflected in our ability to explain the significant historical changes in the distribution and abundance of the disease and its vector. METHODOLOGY/PRINCIPAL FINDINGS: Here we combine daily weather records with simulation modelling techniques to explain vector (Aedes aegypti (L. persistence within its current and historic ranges in Australia. We show that, in regions where dengue presently occurs in Australia (the Wet Tropics region of Far North Queensland, conditions are persistently suitable for year-round adult Ae. aegypti activity and oviposition. In the historic range, however, the vector is vulnerable to periodic extinction due to the combined influence of adult activity constraints and stochastic loss of suitable oviposition sites. CONCLUSIONS/SIGNIFICANCE: These results, together with changes in water-storage behaviour by humans, can explain the observed historical range contraction of the disease vector. For these reasons, future eradication of dengue in wet tropical regions will be extremely difficult through classical mosquito control methods alone. However, control of Ae. aegypti in sub-tropical and temperate regions will be greatly facilitated by government policy regulating domestic water-storage. Exploitation of the natural vulnerabilities of dengue vectors (e.g., habitat specificity, climatic limitations should be integrated with the emerging novel transgenic and symbiotic bacterial control techniques to develop future control and elimination strategies.

Rotenoids from Tephrosia toxicaria with larvicidal activity against Aedes aegypti, the main vector of dengue fever

International Nuclear Information System (INIS)

Vasconcelos, Jackson Nunes e; Santiago, Gilvandete Maria Pinheiro; Lima, Jefferson Queiroz; Arriaga, Angela Martha Campos

2012-01-01

In the search for new larvicides from plants, we have investigated the potential activity of the rotenoids deguelin (1), 12a-hydroxy-a-toxicarol (2) and tephrosin (3), isolated from the bioactive ethanol extract of roots of Tephrosia toxicaria Pers., against Aedes aegypti, the main vector of dengue. The absolute configuration of these compounds was determined by circular dichroism (CD) spectra. The LC50 values of the compounds evaluated justify the potential of T. toxicaria as a new natural larvicide. (author)

Population of Aedes sp in Highland of Wonosobo District and Its Competence as A Dengue Vector

Science.gov (United States)

Martini, Martini; Widjanarko, Bagoes; Hestiningsih, Retno; Purwantisari, Susiana; Yuliawati, Sri

2017-02-01

The increased cases of dengue fever have occurred in the highland of Wonosobo District, and the epidemic taken place in 2009 had 59.3 cases per 100,000 populations. This study aimed to describe of vector competence of the mosquitoes as a dengue vector in the highland of Wonosobo District, Central Java Province. The serial laboratory work was done to measure of vector competence complementary with vector bionomic study. The samples were 20 villages, which were located at Wonosobo sub district. Every village was observed about 15-20 houses. The observed variables were vector competition, bionomic and transovarial infection level, and titer of virus on the mosquitoes after injection. Immunohistochemistry or IHC methods were used to identify transovarial infection status. The number of Ae. aegypti and Ae. albopictus were almost similar and both were found indoors or outdoors. Based on HI and OI index, the larvae density in the highland was enough high than standard of the program. Transovarial infection was found on Ae. aegypti and Ae. albopictus. Environment parameters such as temperature and relative humidity fulfilled the optimum requirement to support the vectors’ life cycle. Transovarial infection has been proven, thus, it indicates that the local transmission has been occurred in this area. Titer of virus was also increasing after day per day. This indicate that the mosquitoes has the ability being vector. As used to do in other area, it is important to conduct breeding places elimination (PSN) indoors as well as outdoors, through active participation of the community in highland area.

Hypocholesterolemia as a predictor of disease severity in dengue fever

International Nuclear Information System (INIS)

Lodhi, S.; Tahira, Q.A.

2014-01-01

Objectives: The objective of this study was to determine the difference between total cholesterol (TC) of dengue fever (DF) and dengue hemorrhagic fever (DHF) patients and also between DHF patients with favourable (DHF I and II) and adverse (DHF III and IV) outcome. Methodology: This comparative cross - sectional study was conducted in the Department of Medicine, Mayo Hospital, Lahore, from August to November 2012. The study comprised of 100 febrile patients with positive dengue serology. TC was measured on the admission day. The patients were observed during admission period for clinical outcome i.e. DF and DHF. DHF patients were graded as I - IV and grouped as favourable (I and II) and adverse (III and IV) out- come. Results: Out of 100 patients included in the study, 64 were males and 36 were females with mean age 33.03 ± 14.5 years and mean TC 3.02 ± 0.88 mmollL. The 63 DF and 37 DHF patients had mean ages of 30.21 ± 12.7 and 37.84 ± 16.2lyears respectively (p-value 0.017) and mean TC 3.43 +- 0.79 and 2.34 ± 0.56 mmollL respectively (p-value 0.000). M:F for DF and DHF was 2:1 and 1.47:1 respectively (p-value 0.001). Among 37 DHF patients, there were 16 DHF I, 8 DHF II, 10 DHF III and 3 DHF IV patients. For DHF I - IV, mean TC was 2.77 ± 0.45, 2.16 ± 0.33, 2.05 ± 0.35 and 1.49 ± 0.35 mmollL respectively. DHF patients with favourable and adverse out.come had mean TC 2.55 ± 0.5 and 1.92 ± 0.42 mmolll respectively (p = value 0.000). Conclusion: Low serum TC strongly correlated with disease severity in dengue fever patients. (author)

Climate Change and Aedes Vectors: 21st Century Projections for Dengue Transmission in Europe

Directory of Open Access Journals (Sweden)

Jing Liu-Helmersson

2016-05-01

Full Text Available Warming temperatures may increase the geographic spread of vector-borne diseases into temperate areas. Although a tropical mosquito-borne viral disease, a dengue outbreak occurred in Madeira, Portugal, in 2012; the first in Europe since 1920s. This outbreak emphasizes the potential for dengue re-emergence in Europe given changing climates. We present estimates of dengue epidemic potential using vectorial capacity (VC based on historic and projected temperature (1901–2099. VC indicates the vectors' ability to spread disease among humans. We calculated temperature-dependent VC for Europe, highlighting 10 European cities and three non-European reference cities. Compared with the tropics, Europe shows pronounced seasonality and geographical heterogeneity. Although low, VC during summer is currently sufficient for dengue outbreaks in Southern Europe to commence–if sufficient vector populations (either Ae. aegypti and Ae. albopictus were active and virus were introduced. Under various climate change scenarios, the seasonal peak and time window for dengue epidemic potential increases during the 21st century. Our study maps dengue epidemic potential in Europe and identifies seasonal time windows when major cities are most conducive for dengue transmission from 1901 to 2099. Our findings illustrate, that besides vector control, mitigating greenhouse gas emissions crucially reduces the future epidemic potential of dengue in Europe.

Dengue fever spreading based on probabilistic cellular automata with two lattices

Science.gov (United States)

Pereira, F. M. M.; Schimit, P. H. T.

2018-06-01

Modeling and simulation of mosquito-borne diseases have gained attention due to a growing incidence in tropical countries in the past few years. Here, we study the dengue spreading in a population modeled by cellular automata, where there are two lattices to model the human-mosquitointeraction: one lattice for human individuals, and one lattice for mosquitoes in order to enable different dynamics in populations. The disease considered is the dengue fever with one, two or three different serotypes coexisting in population. Although many regions exhibit the incidence of only one serotype, here we set a complete framework to also study the occurrence of two and three serotypes at the same time in a population. Furthermore, the flexibility of the model allows its use to other mosquito-borne diseases, like chikungunya, yellow fever and malaria. An approximation of the cellular automata is proposed in terms of ordinary differential equations; the spreading of mosquitoes is studied and the influence of some model parameters are analyzed with numerical simulations. Finally, a method to combat dengue spreading is simulated based on a reduction of mosquito birth and mosquito bites in population.

The place of health and the health of place: dengue fever and urban governance in Putrajaya, Malaysia.

Science.gov (United States)

Mulligan, K; Elliott, S J; Schuster-Wallace, C

2012-05-01

This case study investigates the connections among urban planning, governance and dengue fever in an emerging market context in the Global South. Key informant interviews were conducted with leading figures in public health, urban planning and governance in the planned city of Putrajaya, Malaysia. Drawing on theories of urban political ecology and ecosocial epidemiology, the qualitative study found the health of place - expressed as dengue-bearing mosquitoes and dengue fever in human bodies in the urban environment - was influenced by the place of health in a hierarchy of urban priorities. Copyright © 2012 Elsevier Ltd. All rights reserved.

[The fourth horseman: The yellow fever].

Science.gov (United States)

Vallejos-Parás, Alfonso; Cabrera-Gaytán, David Alejandro

2017-01-01

Dengue virus three, Chikunguya and Zika have entered the national territory through the south of the country. Cases and outbreaks of yellow fever have now been identified in the Americas where it threatens to expand. Although Mexico has a robust epidemiological surveillance system for vector-borne diseases, our country must be alert in case of its possible introduction into the national territory. This paper presents theoretical assumptions based on factual data on the behavior of yellow fever in the Americas, as well as reflections on the epidemiological surveillance of vector-borne diseases.

WEB Services Implementation on The Report of Dengue Hemorrhagic Fever (DHF At Health Office Karanganyar

Directory of Open Access Journals (Sweden)

Ragil Saputra

2013-06-01

Full Text Available Abstract— Dengue Hemorrhagic Fever (DHF is one of the infectious diseases that frequently leads to Extraordinary Situation. The management of report is conducted by Health Community Center which subsequently gives report to Health Office. A problem arising from the report management is the fact that the report is conducted manually, therefore, the data is less valid and is not processed as quickly as possible. The quick and accurate data report system enables to lessen the risk of Dengue Hemorrhagic Fever. Due to this fact, it is undeniable necessary to provide an integrated inter-system of Dengue Fever report. This system includes an inter-system between one Health Community Center to another and to the system in Health Office. The integration of inter-system report is able to be conducted by the use of web service technology. Therefore, this research focuses on the development of Web Service based integrated system on the report of Dengue Fever. Data exchange is conducted in XML form by the application of SOAP and WSDL technologies. Library NuSOAP is necessary to provide class soapClient and soapServer. In other words, it functions as the listener whose functions are to receive and to respond at the access demand toward web service. The result is web service based report system which has dual functions since the system has functions to be either server or client. Keywords— web service, integration, SOAP, DHF.

Community effectiveness of copepods for dengue vector control: systematic review.

Science.gov (United States)

Lazaro, A; Han, W W; Manrique-Saide, P; George, L; Velayudhan, R; Toledo, J; Runge Ranzinger, S; Horstick, O

2015-06-01

Vector control remains the only available method for primary prevention of dengue. Several interventions exist for dengue vector control, with limited evidence of their efficacy and community effectiveness. This systematic review compiles and analyses the existing global evidence for community effectiveness of copepods for dengue vector control. The systematic review follows the PRISMA statement, searching six relevant databases. Applying all inclusion and exclusion criteria, 11 articles were included. There is evidence that cyclopoid copepods (Mesocyclops spp.) could potentially be an effective vector control option, as shown in five community effectiveness studies in Vietnam. This includes long-term effectiveness for larval and adult control of Ae. aegypti, as well as dengue incidence. However, this success has so far not been replicated elsewhere (six studies, three community effectiveness studies--Costa Rica, Mexico and USA, and three studies analysing both efficacy and community effectiveness--Honduras, Laos and USA), probably due to community participation, environmental and/or biological factors. Judging by the quality of existing studies, there is a lack of good study design, data quality and appropriate statistics. There is limited evidence for the use of cyclopoid copepods as a single intervention. There are very few studies, and more are needed in other communities and environments. Clear best practice guidelines for the methodology of entomological studies should be developed. © 2015 John Wiley & Sons Ltd.

Surge of Dengue Virus Infection and Chikungunya Fever in Bali in 2010: The Burden of Mosquito-Borne Infectious Diseases in a Tourist Destination

Science.gov (United States)

Yoshikawa, Minako Jen; Kusriastuti, Rita

2013-01-01

Labor flow and travelers are important factors contributing to the spread of Dengue virus infection and chikungunya fever. Bali Province of Indonesia, a popular resort and tourist destination, has these factors and suffers from mosquito-borne infectious diseases. Using area study approach, a series of fieldwork was conducted in Bali to obtain up-to-date primary disease data, to learn more about public health measures, and to interview health officers, hotel personnel, and other resource persons. The national data including information on two other provinces were obtained for comparison. The health ministry reported 5,810 and 11,697 cases of dengue hemorrhagic fever in Bali in 2009 and 2010, respectively. Moreover, two densely populated tourist areas and one district have shown a particularly high incidence and sharp increases in 2010. Cases of chikungunya fever reported in Bali more than doubled in 2010 from the previous year. Our findings suggest that Bali can benefit from a significant reduction in vector populations and dissemination of disease preventive knowledge among both local residents and foreign visitors. This will require a concerted and trans-border approach, which may prove difficult in the province. PMID:23874141

A successful management of dengue fever in pregnancy: Report of two cases

Directory of Open Access Journals (Sweden)

Singh N

2008-01-01

Full Text Available In the most recent outbreak of degue fever in India, we encountered at least seven cases of fever with thrombocytopenia in pregnancy but only two were seropositive for dengue. In one of the cases there was postpartum hemorrhage while in the other case there was perinatal transmission to the neonate requiring platelet transfusions. The diagnostic difficulties in pregnancy and the management are discussed.

FACTORS PREDICTING MORBIDITY IN PATIENTS WITH DENGUE FEVER IN A TERTIARY CARE HOSPITAL

Directory of Open Access Journals (Sweden)

Muhammad Imran Hasan Khan

2013-02-01

Full Text Available Introduction: Dengue virus (DENV affects over half the world’s population in 112 countries, and dengue fever (DF is the second largest arthropod borne infectious global hazard after malaria with complications like Dengue Hemorrhagic Fever (DHF and Dengue Shock Syndrome (DSS accounting for significant morbidity and mortality world over. Pakistan is significantly affected with DENV infection and to-date no study identifying risk factors associated with complications of DF has been done. Methods: 997 confirmed cases of DF were collected in a tertiary care hospital in Lahore, Pakistan and their clinical and biochemical data were collected. Univariate, multivariate and logistics regression analysis was performed to identify risk factors associated with development of DHF and DSS. Results: Bleeding OR 70.7 (CI 38.4-129.9, deranged liver function test OR 1.9 (CI 0.97-0.99, platelet count on admission less than 50,000 x109/L OR 0.16 (CI 0.13-0.19, presence of urinary red blood cells OR 1.4 (CI 0.179-0.900 and presence of urinary protein OR 1.1 (CI 0.191-0.974 were related to development of DHF and DSS.

Dengue hemorrhagic fever and typhoid fever association based on spatial standpoint using scan statistics in DKI Jakarta

Science.gov (United States)

Hervind, Widyaningsih, Y.

2017-07-01

Concurrent infection with multiple infectious agents may occur in one patient, it appears frequently in dengue hemorrhagic fever (DHF) and typhoid fever. This paper depicted association between DHF and typhoid based on spatial point of view. Since paucity of data regarding dengue and typhoid co-infection, data that be used are the number of patients of those diseases in every district (kecamatan) in Jakarta in 2014 and 2015 obtained from Jakarta surveillance website. Poisson spatial scan statistics is used to detect DHF and typhoid hotspots area district in Jakarta separately. After obtain the hotspot, Fisher's exact test is applied to validate association between those two diseases' hotspot. The result exhibit hotspots of DHF and typhoid are located around central Jakarta. The further analysis used Poisson space-time scan statistics to reveal the hotspot in term of spatial and time. DHF and typhoid fever more likely occurr from January until May in the area which is relatively similar with pure spatial result. Preventive action could be done especially in the hotspot areas and it is required further study to observe the causes based on characteristics of the hotspot area.

Evaluation of the national Notifiable Diseases Surveillance System for dengue fever in Taiwan, 2010-2012.

Directory of Open Access Journals (Sweden)

Caoimhe McKerr

2015-03-01

Full Text Available In Taiwan, around 1,500 cases of dengue fever are reported annually and incidence has been increasing over time. A national web-based Notifiable Diseases Surveillance System (NDSS has been in operation since 1997 to monitor incidence and trends and support case and outbreak management. We present the findings of an evaluation of the NDSS to ascertain the extent to which dengue fever surveillance objectives are being achieved.We extracted the NDSS data on all laboratory-confirmed dengue fever cases reported during 1 January 2010 to 31 December 2012 to assess and describe key system attributes based on the Centers for Disease Control and Prevention surveillance evaluation guidelines. The system's structure and processes were delineated and operational staff interviewed using a semi-structured questionnaire. Crude and age-adjusted incidence rates were calculated and key demographic variables were summarised to describe reporting activity. Data completeness and validity were described across several variables.Of 5,072 laboratory-confirmed dengue fever cases reported during 2010-2012, 4,740 (93% were reported during July to December. The system was judged to be simple due to its minimal reporting steps. Data collected on key variables were correctly formatted and usable in > 90% of cases, demonstrating good data completeness and validity. The information collected was considered relevant by users with high acceptability. Adherence to guidelines for 24-hour reporting was 99%. Of 720 cases (14% recorded as travel-related, 111 (15% had an onset >14 days after return, highlighting the potential for misclassification. Information on hospitalization was missing for 22% of cases. The calculated PVP was 43%.The NDSS for dengue fever surveillance is a robust, well maintained and acceptable system that supports the collection of complete and valid data needed to achieve the surveillance objectives. The simplicity of the system engenders compliance leading to

Clinical presentation and laboratory findings for the first autochthonous cases of dengue fever in Madeira island, Portugal, October 2012.

Science.gov (United States)

Alves, M J; Fernandes, P L; Amaro, F; Osório, H; Luz, T; Parreira, P; Andrade, G; Zé-Zé, L; Zeller, H

2013-02-07

An outbreak of dengue fever in Madeira island was reported in 2012. Clinical and laboratory findings of the first two laboratory-confirmed autochthonous cases are reported. Both cases had fever (≥38 °C) and petechial rash. Symptoms also included myalgia, asthenia, nausea, vomiting, anorexia, diffuse abdominal pain, and diarrhoea. The two cases were confirmed by serology and one tested positive for a dengue viral sequence. Dengue virus serotype DEN-1 was identified with probable Central or South American origin.

Spatial evaluation and modeling of Dengue seroprevalence and vector density in Rio de Janeiro, Brazil.

Directory of Open Access Journals (Sweden)

Nildimar Alves Honório

2009-11-01

Full Text Available Rio de Janeiro, Brazil, experienced a severe dengue fever epidemic in 2008. This was the worst epidemic ever, characterized by a sharp increase in case-fatality rate, mainly among younger individuals. A combination of factors, such as climate, mosquito abundance, buildup of the susceptible population, or viral evolution, could explain the severity of this epidemic. The main objective of this study is to model the spatial patterns of dengue seroprevalence in three neighborhoods with different socioeconomic profiles in Rio de Janeiro. As blood sampling coincided with the peak of dengue transmission, we were also able to identify recent dengue infections and visually relate them to Aedes aegypti spatial distribution abundance. We analyzed individual and spatial factors associated with seroprevalence using Generalized Additive Model (GAM.Three neighborhoods were investigated: a central urban neighborhood, and two isolated areas characterized as a slum and a suburban area. Weekly mosquito collections started in September 2006 and continued until March 2008. In each study area, 40 adult traps and 40 egg traps were installed in a random sample of premises, and two infestation indexes calculated: mean adult density and mean egg density. Sera from individuals living in the three neighborhoods were collected before the 2008 epidemic (July through November 2007 and during the epidemic (February through April 2008. Sera were tested for DENV-reactive IgM, IgG, Nested RT-PCR, and Real Time RT-PCR. From the before-after epidemics paired data, we described seroprevalence, recent dengue infections (asymptomatic or not, and seroconversion. Recent dengue infection varied from 1.3% to 14.1% among study areas. The highest IgM seropositivity occurred in the slum, where mosquito abundance was the lowest, but household conditions were the best for promoting contact between hosts and vectors. By fitting spatial GAM we found dengue seroprevalence hotspots located at the

Emerging Vector-Borne Diseases.

Science.gov (United States)

Huntington, Mark K; Allison, Jay; Nair, Dilip

2016-10-01

Several mosquito-borne viral infections have recently emerged in North America; West Nile virus is the most common in the United States. Although West Nile virus generally causes a self-limited, flulike febrile illness, a serious neuroinvasive form may occur. Dengue is the most common vector-borne viral disease worldwide, and it has been a significant public health threat in the United States since 2009. Known as breakbone fever for its severe myalgias and arthralgias, dengue may cause a hemorrhagic syndrome. Chikungunya also causes flulike febrile illness and disabling arthralgias. Although meningoencephalitis may occur with chikungunya, bleeding is uncommon. Symptoms of Zika virus infection are similar to those of dengue, but milder. Zika virus increases the risk of fetal brain abnormalities, including microcephaly, if a pregnant woman is infected. Zika virus is spread through Aedes albopictus mosquito bites, is transmitted sexually, and may rarely spread nonsexually from person to person. Diagnosis of these vectorborne infections is clinical and serologic, and treatment is supportive. Other, well-established vector-borne diseases are also important. Ehrlichiosis is a tick-borne bacterial disease that presents as a nonspecific syndrome of fever, headache, malaise, and myalgias. It is diagnosed via blood smear testing, with confirmatory serology. Ehrlichiosis is treated with doxycycline. Rickettsial infections are transmitted by fleas, mites, and ticks, and severity ranges from mild to life threatening. Rocky Mountain spotted fever, the most significant rickettsial infection, is primarily a clinical diagnosis that presents as fever, headache, myalgias, petechial rash, and tick exposure. Doxycycline is effective for rickettsial infections if administered promptly. Vector avoidance strategies are critical to the prevention of all of these infections.

Aedes (Stegomyia) albopictus (Skuse), a potential new Dengue vector in southern Cameroon.

OpenAIRE

Fontenille, D.; Toto, J. C.

2001-01-01

Aedes albopictus, a mosquito vector of Dengue virus, has been recorded for the first time in Cameroon. Entomologic surveys in 2000 demonstrated that it is widespread in southern Cameroon, colonizing a wide variety of breeding sites and biting humans in every district surveyed. The presence of this vector increases the risk for emergence of dengue in Cameroon.

DengueTools: innovative tools and strategies for the surveillance and control of dengue

Directory of Open Access Journals (Sweden)

Annelies Wilder-Smith

2012-03-01

Full Text Available Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of ‘Comprehensive control of Dengue fever under changing climatic conditions’. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named ‘DengueTools’ to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe in the context of globalization and climate change.The consortium comprises 12 work packages to address a set of research questions in three areas: Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring. Research area 2: Develop novel strategies to prevent dengue in children. Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change.In this paper, we report on the rationale and specific study objectives of ‘DengueTools’. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant

DengueTools: innovative tools and strategies for the surveillance and control of dengue.

Science.gov (United States)

Wilder-Smith, Annelies; Renhorn, Karl-Erik; Tissera, Hasitha; Abu Bakar, Sazaly; Alphey, Luke; Kittayapong, Pattamaporn; Lindsay, Steve; Logan, James; Hatz, Christoph; Reiter, Paul; Rocklöv, Joacim; Byass, Peter; Louis, Valérie R; Tozan, Yesim; Massad, Eduardo; Tenorio, Antonio; Lagneau, Christophe; L'Ambert, Grégory; Brooks, David; Wegerdt, Johannah; Gubler, Duane

2012-01-01

Dengue fever is a mosquito-borne viral disease estimated to cause about 230 million infections worldwide every year, of which 25,000 are fatal. Global incidence has risen rapidly in recent decades with some 3.6 billion people, over half of the world's population, now at risk, mainly in urban centres of the tropics and subtropics. Demographic and societal changes, in particular urbanization, globalization, and increased international travel, are major contributors to the rise in incidence and geographic expansion of dengue infections. Major research gaps continue to hamper the control of dengue. The European Commission launched a call under the 7th Framework Programme with the title of 'Comprehensive control of Dengue fever under changing climatic conditions'. Fourteen partners from several countries in Europe, Asia, and South America formed a consortium named 'DengueTools' to respond to the call to achieve better diagnosis, surveillance, prevention, and predictive models and improve our understanding of the spread of dengue to previously uninfected regions (including Europe) in the context of globalization and climate change.The consortium comprises 12 work packages to address a set of research questions in three areas:Research area 1: Develop a comprehensive early warning and surveillance system that has predictive capability for epidemic dengue and benefits from novel tools for laboratory diagnosis and vector monitoring.Research area 2: Develop novel strategies to prevent dengue in children.Research area 3: Understand and predict the risk of global spread of dengue, in particular the risk of introduction and establishment in Europe, within the context of parameters of vectorial capacity, global mobility, and climate change.In this paper, we report on the rationale and specific study objectives of 'DengueTools'. DengueTools is funded under the Health theme of the Seventh Framework Programme of the European Community, Grant Agreement Number: 282589 Dengue Tools.

Current status, challenges and perspectives in the development of vaccines against yellow fever, dengue, Zika and chikungunya viruses.

Science.gov (United States)

Silva, José V J; Lopes, Thaísa R R; Oliveira-Filho, Edmilson F de; Oliveira, Renato A S; Durães-Carvalho, Ricardo; Gil, Laura H V G

2018-06-01

Emerging and re-emerging viral infections transmitted by insect vectors (arthopode-borne viruses, arbovirus) are a serious threat to global public health. Among them, yellow fever (YFV), dengue (DENV), chikungunya (CHIKV) and Zika (ZIKV) viruses are particularly important in tropical and subtropical regions. Although vector control is one of the most used prophylactic measures against arboviruses, it often faces obstacles, such as vector diversity, uncontrolled urbanization and increasing resistance to insecticides. In this context, vaccines may be the best control strategy for arboviral diseases. Here, we provide a general overview about licensed vaccines and the most advanced vaccine candidates against YFV, DENV, CHIKV and ZIKV. In particular, we highlight vaccine difficulties, the current status of the most advanced strategies and discuss how the molecular characteristics of each virus can influence the choice of the different vaccine formulations. Copyright © 2018 Elsevier B.V. All rights reserved.

Exploring the molecular basis of insecticide resistance in the dengue vector Aedes aegypti: a case study in Martinique Island (French West Indies

Directory of Open Access Journals (Sweden)

Yébakima André

2009-10-01

Full Text Available Abstract Background The yellow fever mosquito Aedes aegypti is a major vector of dengue and hemorrhagic fevers, causing up to 100 million dengue infections every year. As there is still no medicine and efficient vaccine available, vector control largely based on insecticide treatments remains the only method to reduce dengue virus transmission. Unfortunately, vector control programs are facing operational challenges with mosquitoes becoming resistant to commonly used insecticides. Resistance of Ae. aegypti to chemical insecticides has been reported worldwide and the underlying molecular mechanisms, including the identification of enzymes involved in insecticide detoxification are not completely understood. Results The present paper investigates the molecular basis of insecticide resistance in a population of Ae. aegypti collected in Martinique (French West Indies. Bioassays with insecticides on adults and larvae revealed high levels of resistance to organophosphate and pyrethroid insecticides. Molecular screening for common insecticide target-site mutations showed a high frequency (71% of the sodium channel 'knock down resistance' (kdr mutation. Exposing mosquitoes to detoxification enzymes inhibitors prior to bioassays induced a significant increased susceptibility of mosquitoes to insecticides, revealing the presence of metabolic-based resistance mechanisms. This trend was biochemically confirmed by significant elevated activities of cytochrome P450 monooxygenases, glutathione S-transferases and carboxylesterases at both larval and adult stages. Utilization of the microarray Aedes Detox Chip containing probes for all members of detoxification and other insecticide resistance-related enzymes revealed the significant constitutive over-transcription of multiple detoxification genes at both larval and adult stages. The over-transcription of detoxification genes in the resistant strain was confirmed by using real-time quantitative RT

Cerebral vasculitis and lateral rectus palsy - two rare central nervous system complications of dengue fever: two case reports and review of the literature.

Science.gov (United States)

Herath, H M M; Hewavithana, J S; De Silva, C M; Kularathna, O A R; Weerasinghe, N P

2018-04-19

Dengue fever is a common mosquito-borne viral illness with a clinical spectrum ranging from a simple febrile illness to potentially life-threatening complications such as dengue hemorrhagic fever and dengue shock syndrome. Dengue infection can affect many organs, including the central nervous system. The neurological manifestations reported in dengue infections are meningitis, encephalitis, stroke, acute disseminated encephalomyelitis, and Guillain-Barré syndrome. We report the cases of two interesting patients with confirmed dengue infection who presented with complications of possible central nervous system vasculitis and cranial nerve palsy. The first patient was a 53-year-old previously healthy Singhalese woman who developed acute-onset slurring of speech and ataxia with altered sensorium 1 day after recovery from a critical period of dengue hemorrhagic fever. Subsequent investigations revealed evidence of encephalopathy with brainstem ischemic infarctions. Her clinical picture was compatible with central nervous system vasculitis. She was treated successfully with intravenous steroids and had a full functional recovery. The second patient was a middle-aged Singhalese woman who had otherwise uncomplicated dengue infection. She developed binocular diplopia on day 4 of fever. An ocular examination revealed a convergent squint in the left eye with lateral rectus palsy but no other neurological manifestation. Central nervous system vasculitis due to dengue infection is a very rare phenomenon, and to the best of our knowledge, only one case of central nervous system vasculitis has been reported to date, in a patient of pediatric age. Cranial nerve palsy related to dengue infection is also rare, and only a few cases of isolated abducens nerve palsy have been reported to date. The two cases described in this report illustrate the rare but important central nervous system manifestations of dengue fever and support the fact that the central nervous system is one of the

Differentiating between dengue fever and malaria using hematological parameters in endemic areas of Thailand.

Science.gov (United States)

Kotepui, Manas; PhunPhuech, Bhukdee; Phiwklam, Nuoil; Uthaisar, Kwuntida

2017-03-02

Dengue fever (DF) and malaria are the two major public health concerns in tropical countries such as Thailand. Early differentiation between dengue and malaria could help clinicians to identify patients who should be closely monitored for signs of dengue hemorrhagic fever or severe malaria. This study aims to build knowledge on diagnostic markers that are used to discriminate between the infections, which frequently occur in malaria-endemic areas, such as the ones in Thailand. A retrospective study was conducted in Phop Phra Hospital, a hospital located in the Thailand-Burma border area, a malaria-endemic area, between 2013 and 2015. In brief, data on 336 patients infected with malaria were compared to data on 347 patients infected with DF. White blood cells, neutrophil, monocyte, eosinophil, neutrophil-lymphocyte ratio, and monocyte-lymphocyte ratio were significantly lower in patients with DF compared to patients with malaria (P dengue and malaria infection. This study concluded that several hematological parameters were different for diagnosing DF and malaria. A decision tree model revealed that using neutrophils, lymphocyte, MCHC, and gender was guided to discriminate patients with dengue and malaria infection. In addition, using these markers will thus lead to early detection, diagnosis, and prompt treatment of these tropical diseases.

Aedes albopictus (Skuse, 1894 infected with the American-Asian genotype of dengue type 2 virus in Medellín suggests its possible role as vector of dengue fever in Colombia

Directory of Open Access Journals (Sweden)

Andrés Gómez-Palacio

2017-03-01

Conclusion: We report the presence Ae. albopictus naturally infected with the Asian-American genotype of DENV-2 in Colombia. The presence of Ae. albopictus specimens carrying the most common genotype infecting humans in a highly populated city such as Medellín indicates its potential role as dengue vector in Colombia and highlights the relevance of including it in current vector surveillance strategies.

Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen.

Science.gov (United States)

Madani, Tariq A; Abuelzein, El-Tayeb M E; Al-Bar, Hussein M S; Azhar, Esam I; Kao, Moujahed; Alshoeb, Haj O; Bamoosa, Alabd R

2013-03-14

Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. From 15-17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. DENV-3 was confirmed to be the cause of an outbreak of VHF in Al-Mukalla. It is important to use both IgM and NS1-antigen

Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen

Science.gov (United States)

2013-01-01

Background Investigations were conducted by the authors to explore an outbreak of viral hemorrhagic fever (VHF) reported in 2010 from Al-Mukalla city, the capital of Hadramout in Yemen. Methods From 15–17 June 2010, the outbreak investigation period, specimens were obtained within 7 days after onset of illness of 18 acutely ill patients hospitalized with VHF and 15 household asymptomatic contacts of 6 acute cases. Additionally, 189 stored sera taken from acutely ill patients with suspected VHF hospitalized in the preceding 12 months were obtained from the Ministry of Health of Yemen. Thus, a total of 222 human specimens were collected; 207 specimens from acute cases and 15 specimens from contacts. All samples were tested with RT-PCR for dengue (DENV), Alkhumra (ALKV), Rift Valley Fever (RVFV), Yellow Fever (YFV), and Chikungunya (CHIKV) viruses. Samples were also tested for DENV IgM, IgG, and NS1-antigen. Medical records of patients were reviewed and demographic, clinical, and laboratory data was collected. Results Of 207 patients tested, 181 (87.4%) patients were confirmed to have acute dengue with positive dengue NS1-antigen (97 patients, 46.9%) and/or IgM (163 patients, 78.7%). Of the 181 patients with confirmed dengue, 100 (55.2%) patients were IgG-positive. DENV RNA was detected in 2 (1%) patients with acute symptoms; both samples were molecularly typed as DENV type 3. No other VHF viruses were detected. For the 15 contacts tested, RT-PCR tests for the five viruses were negative, one contact was dengue IgM positive, and another one was dengue IgG positive. Of the 181 confirmed dengue patients, 120 (66.3%) patients were males and the median age was 24 years. The most common manifestations included fever (100%), headache (94.5%), backache (93.4%), malaise (88.4%), arthralgia (85.1%), myalgia (82.3%), bone pain (77.9%), and leukopenia (76.2%). Two (1.1%) patients died. Conclusions DENV-3 was confirmed to be the cause of an outbreak of VHF in Al

In silico prediction of monovalent and chimeric tetravalent vaccines for prevention and treatment of dengue fever.

Science.gov (United States)

Vijayakumar, Subramaniyan; Ramesh, Venkatachalam; Prabhu, Srinivasan; Manogar, Palani

2017-11-01

Reverse vaccinology method was used to predict the monovalent peptide vaccine candidate to produce antibodies for therapeutic purpose and to predict tetravalent vaccine candidate to act as a common vaccine to cover all the fever dengue virus serotypes. Envelope (E)-proteins of DENV-1-4 serotypes were used for vaccine prediction using NCBI, Uniprot/Swissprot, Swiss-prot viewer, VaxiJen V2.0, TMHMM, BCPREDS, Propred-1, Propred and MHC Pred,. E-proteins of DENV-1-4 serotypes were identified as antigen from which T cell epitopes, through B cell epitopes, were predicted to act as peptide vaccine candidates. Each selected T cell epitope of E-protein was confirmed to act as vaccine and to induce complementary antibody against particular serotype of dengue virus. Chimeric tetravalent vaccine was formed by the conjugation of four vaccines, each from four dengue serotypes to act as a common vaccine candidate for all the four dengue serotypes. It can be justifiably concluded that the monovalent 9-mer T cell epitope for each DENV serotypes can be used to produce specific antibody agaomst dengue virus and a chimeric common tetravalent vaccine candidate to yield a comparative vaccine to cover any of the four dengue virus serotype. This vaccine is expected to act as highly immunogenic against preventing dengue fever.

Dengue in Grenada El dengue en el país de Granada

Directory of Open Access Journals (Sweden)

André Panagos

2005-04-01

Full Text Available OBJECTIVES: Dengue fever is endemic in the country of Grenada and is grossly underreported as a source of morbidity. The goal of this study was to assess the status of dengue fever in a representative community in Grenada. METHODS: Surveys were conducted in the Mont Tout/Grand Anse Valley area in the parish of St. George's from March to June 1996. The objectives of the survey were to: (1 to assess the knowledge, attitudes, and practices (KAP of residents; (2 to determine the presence of larval and adult Aedes aegypti and their potential breeding sites; and (3 to identify the seroprevalence of specific immunoglobulin G (IgG dengue antibodies in the local population. RESULTS: Out of the 102 respondents to the KAP survey, 100 of them (98% reported never having had dengue fever. Of the 75 persons who agreed to have blood samples taken, 70 of them (93% (95% confidence interval = 85.1%-97.8% tested positive with the IgG enzyme-linked immunosorbent assay, indicating past exposure. In terms of water storage, 98 of 102 respondents (96% stored fresh water in containers. The vector survey found 57 of the 102 households (56% had Ae. aegypti larvae in water containers on their property, and 94 of 102 dwellings (92% had adult Ae. aegypti mosquitoes indoors. CONCLUSIONS: Although many people were familiar with dengue fever and mosquitoes, the 1996 survey found that their knowledge of the important relationships among mosquitoes, human behavior, and disease transmission was incomplete. Since 1996, continued education efforts have been made in the public school system and with national public health campaigns, yet little effort has been specifically targeted towards our study community. These data suggest Grenada has a need for continued community education that addresses dengue fever transmission and Ae. aegypti reduction.OBJETIVOS: La fiebre del dengue es endémica en el país caribeño de Granada y es grande su subnotificación como fuente de morbilidad. El

CORRELATION OF ULTRASOUND (USG FINDINGS WITH SEROLOGICAL TESTS IN DENGUE FEVER

Directory of Open Access Journals (Sweden)

Dayanand

2016-02-01

Full Text Available INTRODUCTION Dengue is an endemic and epidemic disease of the tropical and subtropical regions. Between September & October 2012, there was an established outbreak of dengue in Hoskote, near Bangalore. Dengue results in serositis, which can be imaged by ultrasonography. OBJECTIVE To correlate the USG findings with the serological tests in paediatric and adult patients. MATERIALS AND METHODS 110 patients with clinical suspicion of dengue fever during the above period underwent serological tests-NS1, IgM and IgG and were evaluated with USG of the abdomen and thorax. The USG findings were correlated with serological tests. RESULTS 67 Patients were seropositive, 43 were seronegative. The USG findings in seropositive paediatric patients (n=32 and adult patients (n=35 respectively were gall bladder (GB wall edema-27 & 31, hepatomegaly-12 &14, ascites-16 & 12, splenomegaly- 15 & 9, right pleural effusion-14 & 13, left and bilateral pleural effusion-7 & 5. CONCLUSION In our study GB wall edema significantly correlated with seropositivity (p value=0.032. Thus ultrasound is an efficient screening tool in a case of dengue outbreak.

Awareness regarding dengue fever among the link workers of urban health centres of Bengaluru CitySouth India

Directory of Open Access Journals (Sweden)

Gowda Giriyanna

2015-06-01

Full Text Available Objective: To assess awareness of link workers regarding dengue fever and its prevention and the effect of health education about dengue and its prevention. Methods: Prospective interventional study was conducted in selected urban health centers of Bengaluru. About 106 link workers selected by systematic random sampling were interviewed by trained investigators. Health education was given to all of them and awareness was reassessed after a gap of one month. Results: Mean age of link workers was (36.95 ± 5.88 years. A total of 49.06% of link workers were aware that dengue is caused by virus, 74.53% were aware of complications of dengue, 87.74 % were aware that dengue is spread by Aedes mosquito. After health education the above observations increased to 81.4%, 87.63%, and 90.72% respectively. Difference between mean preand post-test score was statistically significant (P < 0.05. Conclusions: Awareness regarding dengue fever and its prevention was poor among link workers, which improved significantly after health education.

Increased efficiency in the second-hand tire trade provides opportunity for dengue control.

Science.gov (United States)

Pliego Pliego, Emilene; Velázquez-Castro, Jorge; Eichhorn, Markus P; Fraguela Collar, Andrés

2018-01-21

Dengue fever is increasing in geographical range, spread by invasion of its vector mosquitoes. The trade in second-hand tires has been implicated as a factor in this process because they act as mobile reservoirs of mosquito eggs and larvae. Regional transportation of tires can create linkages between rural areas with dengue and disease-free urban areas, potentially giving rise to outbreaks even in areas with strong local control measures. In this work we sought to model the dynamics of mosquito transportation via the tire trade, in particular to predict its role in causing unexpected dengue outbreaks through vertical transmission of the virus across generations of mosquitoes. We also aimed to identify strategies for regulating the trade in second-hand tires, improving disease control. We created a mathematical model which captures the dynamics of dengue between rural and urban areas, taking into account the movement and storage time of tires, and mosquito diapause. We simulate a series of scenarios in which a mosquito population is introduced to a dengue-free area via movement of tires, either as single or multiple events, increasing the likelihood of a dengue outbreak. A persistent disease state can be induced regardless of whether urban conditions for an outbreak are met, and an existing endemic state can be enhanced by vector input. Finally we assess the potential for regulation of tire processing as a means of reducing the transmission of dengue fever using a specific case study from Puerto Rico. Our work demonstrates the importance of the second-hand tire trade in modulating the spread of dengue fever across regions, in particular its role in introducing dengue to disease-free areas. We propose that reduction of tire storage time and control of their movement can play a crucial role in containing dengue outbreaks. Copyright © 2017 Elsevier Ltd. All rights reserved.

Assessing socioeconomic vulnerability to dengue fever in Cali, Colombia: statistical vs expert-based modeling.

Science.gov (United States)

Hagenlocher, Michael; Delmelle, Eric; Casas, Irene; Kienberger, Stefan

2013-08-14

As a result of changes in climatic conditions and greater resistance to insecticides, many regions across the globe, including Colombia, have been facing a resurgence of vector-borne diseases, and dengue fever in particular. Timely information on both (1) the spatial distribution of the disease, and (2) prevailing vulnerabilities of the population are needed to adequately plan targeted preventive intervention. We propose a methodology for the spatial assessment of current socioeconomic vulnerabilities to dengue fever in Cali, a tropical urban environment of Colombia. Based on a set of socioeconomic and demographic indicators derived from census data and ancillary geospatial datasets, we develop a spatial approach for both expert-based and purely statistical-based modeling of current vulnerability levels across 340 neighborhoods of the city using a Geographic Information System (GIS). The results of both approaches are comparatively evaluated by means of spatial statistics. A web-based approach is proposed to facilitate the visualization and the dissemination of the output vulnerability index to the community. The statistical and the expert-based modeling approach exhibit a high concordance, globally, and spatially. The expert-based approach indicates a slightly higher vulnerability mean (0.53) and vulnerability median (0.56) across all neighborhoods, compared to the purely statistical approach (mean = 0.48; median = 0.49). Both approaches reveal that high values of vulnerability tend to cluster in the eastern, north-eastern, and western part of the city. These are poor neighborhoods with high percentages of young (i.e., local expertise, statistical approaches could be used, with caution. By decomposing identified vulnerability "hotspots" into their underlying factors, our approach provides valuable information on both (1) the location of neighborhoods, and (2) vulnerability factors that should be given priority in the context of targeted intervention

Controlling dengue with vaccines in Thailand.

Directory of Open Access Journals (Sweden)

Dennis L Chao

Full Text Available Dengue is a mosquito-borne infectious disease that constitutes a growing global threat with the habitat expansion of its vectors Aedes aegyti and A. albopictus and increasing urbanization. With no effective treatment and limited success of vector control, dengue vaccines constitute the best control measure for the foreseeable future. With four interacting dengue serotypes, the development of an effective vaccine has been a challenge. Several dengue vaccine candidates are currently being tested in clinical trials. Before the widespread introduction of a new dengue vaccine, one needs to consider how best to use limited supplies of vaccine given the complex dengue transmission dynamics and the immunological interaction among the four dengue serotypes.We developed an individual-level (including both humans and mosquitoes, stochastic simulation model for dengue transmission and control in a semi-rural area in Thailand. We calibrated the model to dengue serotype-specific infection, illness and hospitalization data from Thailand. Our simulations show that a realistic roll-out plan, starting with young children then covering progressively older individuals in following seasons, could reduce local transmission of dengue to low levels. Simulations indicate that this strategy could avert about 7,700 uncomplicated dengue fever cases and 220 dengue hospitalizations per 100,000 people at risk over a ten-year period.Vaccination will have an important role in controlling dengue. According to our modeling results, children should be prioritized to receive vaccine, but adults will also need to be vaccinated if one wants to reduce community-wide dengue transmission to low levels.

Controlling Dengue with Vaccines in Thailand

Science.gov (United States)

Chao, Dennis L.; Halstead, Scott B.; Halloran, M. Elizabeth; Longini, Ira M.

2012-01-01

Background Dengue is a mosquito-borne infectious disease that constitutes a growing global threat with the habitat expansion of its vectors Aedes aegyti and A. albopictus and increasing urbanization. With no effective treatment and limited success of vector control, dengue vaccines constitute the best control measure for the foreseeable future. With four interacting dengue serotypes, the development of an effective vaccine has been a challenge. Several dengue vaccine candidates are currently being tested in clinical trials. Before the widespread introduction of a new dengue vaccine, one needs to consider how best to use limited supplies of vaccine given the complex dengue transmission dynamics and the immunological interaction among the four dengue serotypes. Methodology/Principal Findings We developed an individual-level (including both humans and mosquitoes), stochastic simulation model for dengue transmission and control in a semi-rural area in Thailand. We calibrated the model to dengue serotype-specific infection, illness and hospitalization data from Thailand. Our simulations show that a realistic roll-out plan, starting with young children then covering progressively older individuals in following seasons, could reduce local transmission of dengue to low levels. Simulations indicate that this strategy could avert about 7,700 uncomplicated dengue fever cases and 220 dengue hospitalizations per 100,000 people at risk over a ten-year period. Conclusions/Significance Vaccination will have an important role in controlling dengue. According to our modeling results, children should be prioritized to receive vaccine, but adults will also need to be vaccinated if one wants to reduce community-wide dengue transmission to low levels. PMID:23145197

[A Case of Dengue Fever and Subsequent Long-lasting Depression Accompanied by Alopecia in a Japanese Traveler Returning from Bali, Indonesia].

Science.gov (United States)

Hitani, Akihiro; Yamaya, Waka; To, Masako; Kano, Ichino; Honda-Hosono, Natsue; Takasaki, Tomohiko; Haruki, Kosuke

2015-03-01

Recovery from dengue fever is generally rapid and uneventful. However, recuperation is often prolonged and may be accompanied by noticeable depression. We present herein on a traveler to Indonesia who developed long-lasting depression after the classic symptoms of dengue fever such as fever, arthralgia, and macropapular rash had resolved. A previously healthy 42-year old japanese woman presented to the Travel Clinic of Seirei Yokohama Hospital with complaints of 4 days of fever, joint aches, bone pain, and a macropapular rash on her torso. She had returned from Bali 5 days previously. During her 1-week stay, one day was spent in rural, mountainous areas where she was exposed to several mosquito bites. The 1st serum sample collected 4 days after the disease onset gave positive result in the rapid dengue IgM antibody test and the rapid dengue NS1 antigen immunechromatographic test. The DENV-1 genome was detected with RT-PCR. Her 13-year old son, who had accompanied her, was also diagnosed as having dengue fever and he recovered without event. The Above-mentioned symptoms resolved within one week. However, the patient suffered from prolonged depression. She also noticed loss of hair 3 months after the disease onset Administration of a Serotonin-Noradrenalin Reuptake Inhibitor and a minor tranquillizer required to allow her requied to lead a normal life. Although she gradually felt better, it took approximately 2 years until she had recovered completely without taking any antidepressant and minor tranquillizer. It is a well-known fact in endemic countries that dengue fever could have an significant impact on the patients' mental well-being. However, it appears that physicians in non-endemic countries are not fully aware of the prolonged depression, which can occur subsequent to the acute illness. Follow-up consultations of returing travelers who have recoverd from dengu fever should be arranged to monitor their mental and emotional states closely.

Chikungunya fever: current status in Mexico.

Science.gov (United States)

Nava-Frías, Margarita; Searcy-Pavía, Ricardo Efrén; Juárez-Contreras, Carina Aurora; Valencia-Bautista, Anayeli

Chikungunya fever is a tropical vector-borne disease that has been spreading rapidly around the world during the last 10 years, and which has been usually misdiagnosed as dengue. Nowadays, this disease is increasing in Mexico, mainly in the southern and central zones of the country, being significantly more common in women, children and young adults (28% in<20 years of age). The classical presentation includes fever, arthralgia, polyarthritis, back-pain, and skin rashes. Although symptoms and treatment are similar to those for dengue, there are key clinical features to differentiate these two diseases. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

Current perspectives on the spread of dengue in India

Directory of Open Access Journals (Sweden)

Gupta E

2014-12-01

Full Text Available Ekta Gupta, Neha Ballani Department of Clinical Virology, Institute of Liver and Biliary Sciences, New Delhi, IndiaAbstract: Dengue fever (DF and dengue hemorrhagic fever (DHF are important arthropod-borne viral diseases. Each year, there are ~50 million dengue infections and ~500,000 individuals are hospitalized with DHF, mainly in Southeast Asia. Dengue in India has dramatically expanded over the last few decades, with rapidly changing epidemiology. The first major DHF outbreak in the entire nation occurred in 1996 by dengue virus serotype 2, and after a gap of almost a decade, the country faced yet another DF outbreak in the year 2003 by dengue virus serotype 3. A dramatic increase in the number and frequency of outbreaks followed, and, at present, in most of the states of India, dengue is almost endemic. At present, all the four serotypes are seen in circulation, but the predominant serotype keeps changing. Despite this trend, surveillance, reporting, and diagnosis of dengue remain largely passive in India. More active community-based epidemiological studies with intensive vector control and initiatives for dengue vaccine development should be geared up to control the spread of dengue in India. We review here the factors that may have contributed to the changing epidemiology of dengue in India.Keywords: dengue, epidemiology, India, pathogenesis, vaccine

Evaluation of the Larvicidal Efficacy of Five Indigenous Weeds against an Indian Strain of Dengue Vector, Aedes aegypti L. (Diptera: Culicidae)

Science.gov (United States)

Sharma, Aarti; Kumar, Sarita; Tripathi, Pushplata

2016-01-01

Background and Objectives. Aedes aegypti, dengue fever mosquito, is primarily associated with the transmission of dengue and chikungunya in tropical and subtropical regions of the world. The present investigations were carried out to assess the larvicidal efficiency of five indigenous weeds against Ae. aegypti. Methods. The 1,000 ppm hexane and ethanol extracts prepared from the leaves and stem of five plants (Achyranthes aspera, Cassia occidentalis, Catharanthus roseus, Lantana camara, and Xanthium strumarium) were screened for their larvicidal activity against early fourth instars of dengue vector. The extracts which could cause 80–100% mortality were further investigated for their efficacy. Results. The preliminary screening established the efficacy of hexane extracts as compared to the ethanol extracts. Further investigations revealed the highest larvicidal potential of A. aspera extracts exhibiting LC50 value of 82.555 ppm and 68.133 ppm, respectively. Further, their leaf extracts showed 5–85.9% higher larvicidal activity and stem extracts exhibited 0.23- to 0.85-fold more efficiency than the other four extracts. Conclusion. The present investigations suggest the possible use of A. aspera as an ideal ecofriendly, larvicidal agent for the control of dengue vector, Ae. aegypti. Future studies are, however, required to explore and identify the bioactive component involved and its mode of action. PMID:26941996

Evaluation of the Larvicidal Efficacy of Five Indigenous Weeds against an Indian Strain of Dengue Vector, Aedes aegypti L. (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Aarti Sharma

2016-01-01

Full Text Available Background and Objectives. Aedes aegypti, dengue fever mosquito, is primarily associated with the transmission of dengue and chikungunya in tropical and subtropical regions of the world. The present investigations were carried out to assess the larvicidal efficiency of five indigenous weeds against Ae. aegypti. Methods. The 1,000 ppm hexane and ethanol extracts prepared from the leaves and stem of five plants (Achyranthes aspera, Cassia occidentalis, Catharanthus roseus, Lantana camara, and Xanthium strumarium were screened for their larvicidal activity against early fourth instars of dengue vector. The extracts which could cause 80–100% mortality were further investigated for their efficacy. Results. The preliminary screening established the efficacy of hexane extracts as compared to the ethanol extracts. Further investigations revealed the highest larvicidal potential of A. aspera extracts exhibiting LC50 value of 82.555 ppm and 68.133 ppm, respectively. Further, their leaf extracts showed 5–85.9% higher larvicidal activity and stem extracts exhibited 0.23- to 0.85-fold more efficiency than the other four extracts. Conclusion. The present investigations suggest the possible use of A. aspera as an ideal ecofriendly, larvicidal agent for the control of dengue vector, Ae. aegypti. Future studies are, however, required to explore and identify the bioactive component involved and its mode of action.

Notes from the Field: Outbreak of Locally Acquired Cases of Dengue Fever--Hawaii, 2015.

Science.gov (United States)

Johnston, David; Viray, Melissa; Ushiroda, Jenny; Whelen, A Christian; Sciulli, Rebecca; Gose, Remedios; Lee, Roland; Honda, Eric; Park, Sarah Y

2016-01-22

On October 21, 2015, the Hawaii Department of Health (HDOH) was notified of a positive dengue immunoglobulin M (IgM) antibody result in a woman residing on Hawaii Island (also known as the Big Island). The patient had no history of travel off the island, and other family members reported having similar signs and symptoms, which consisted of fever, headache, myalgias and arthralgias, and a generalized erythematous rash. HDOH initiated an investigation to identify any additional cases and potential exposure sources. On October 24, HDOH received report of a group of mainland U.S. visitors who had traveled together on Hawaii Island, including several who had developed a febrile illness. Additionally, on October 27, HDOH was notified of an unrelated person, also on Hawaii Island, with a positive dengue IgM result. As of November 26, 2015, HDOH had identified 107 laboratory-confirmed cases of dengue fever, with dates of onset ranging from September 11 to November 18, 2015.

Forecasting dengue hemorrhagic fever cases using ARIMA model: a case study in Asahan district

Science.gov (United States)

Siregar, Fazidah A.; Makmur, Tri; Saprin, S.

2018-01-01

Time series analysis had been increasingly used to forecast the number of dengue hemorrhagic fever in many studies. Since no vaccine exist and poor public health infrastructure, predicting the occurrence of dengue hemorrhagic fever (DHF) is crucial. This study was conducted to determine trend and forecasting the occurrence of DHF in Asahan district, North Sumatera Province. Monthly reported dengue cases for the years 2012-2016 were obtained from the district health offices. A time series analysis was conducted by Autoregressive integrated moving average (ARIMA) modeling to forecast the occurrence of DHF. The results demonstrated that the reported DHF cases showed a seasonal variation. The SARIMA (1,0,0)(0,1,1)12 model was the best model and adequate for the data. The SARIMA model for DHF is necessary and could applied to predict the incidence of DHF in Asahan district and assist with design public health maesures to prevent and control the diseases.

Surveillance of vector-borne diseases in Germany: trends and challenges in the view of disease emergence and climate change.

Science.gov (United States)

Jansen, Andreas; Frank, Christina; Koch, Judith; Stark, Klaus

2008-12-01

The changing epidemiology of vector-borne diseases represents a growing threat to human health. Contemporary surveillance systems have to adapt to these changes. We describe temporal trends and geographic origins of vector-borne diseases in Germany with regard to strengths of existing disease surveillance and to areas marked for improvement. We focused on hantavirus infection (endemic in Germany), chikungunya fever (recently emerging in Europe) and dengue fever (imported from tropical regions), representing important subgroups of vector-borne infections. Routine surveillance data on demographics, origin of infection and the date of reporting were analysed. From 2001 through 2007, 3,005 symptomatic hantavirus infections, and 85 cases of chikungunya fever were reported, similarly 1,048 cases of dengue fever in 2002 through 2007. The geographic origin of hantavirus infection was reported for 95.5% of all cases (dengue virus, 98.4%; chikungunya virus, 100%). Hantavirus infections were acquired in Germany in 97.6% of cases (n = 2800). In 2007, there was a marked increase of hantavirus cases, mainly in areas known to be endemic for hantavirus. In 2006, imported cases of chikungunya fever primarily returned from several islands of the Indian Ocean, while the majority of imported cases in 2007 came from India. The reported number of dengue fever cases have increased since 2004. Thailand contributed the largest proportion of cases (17-43% in individual years), followed by India, Brazil and Indonesia. Surveillance of notifiable vector-borne diseases in Germany is able to timely detect spatial and temporal changes of autochthonous an imported infections. Geographic and temporal data obtained by routine surveillance served as a basis for public health recommendations. In addition to surveillance of vector-borne infections in humans, nationwide monitoring programs and inventory techniques for emerging and reemerging vectors and for wildlife disease are warranted.

Health Seeking Behaviour and Treatment Intentions of Dengue and Fever: A Household Survey of Children and Adults in Venezuela

Science.gov (United States)

Elsinga, Jelte; Lizarazo, Erley F.; Vincenti, Maria F.; Schmidt, Masja; Velasco-Salas, Zoraida I.; Arias, Luzlexis; Bailey, Ajay; Tami, Adriana

2015-01-01

Background Dengue in Venezuela is a major public health problem with an increasing incidence of severe cases. Early diagnosis and timely treatment influences the outcome of dengue illness, as delay in care-seeking is significantly associated with complications leading to severe dengue. We aimed to understand patterns of health seeking behaviour (HSB) in individuals exposed to high dengue incidence in order to improve early attendance to health centres. Methods Between September 2013 and February 2014 a cross-sectional household survey was performed in Maracay, Venezuela. Intended HSB of adults and children’s parents/guardians was assessed with respect to fever or suspected dengue. Data was collected through structured questionnaires from 105 individuals. Results Most individuals felt at risk of dengue and believed it could be a deadly disease. In the case of suspected dengue, the majority (60%) would choose to first seek medical help versus first treating at home, in contrast to 11% in the case of fever. Amongst those who decided to visit a doctor, a suspected dengue infection would prompt them to search medical help earlier than if having only fever (ptreating at home in the case of dengue were feeling at risk (OR = 3.29; p = 0.042) and being an adult (as opposed to caring for a child as a parent/guardian; OR = 3.33, p = 0.021), while having had a previous dengue infection (OR = 0.29; p = 0.031) and living in the neighbourhood Caña de Azúcar (OR = 0.28, p = 0.038) were negatively associated with seeking medical care as their first action. Conclusion Knowledge of HSB related to dengue is scarce in the Americas, our study attempts to contribute to a better understanding of HSB in this region. Improving early dengue disease recognition and awareness may enhance prompt attendance to medical care in affected populations and thereby reduce mortality and severity of dengue. Especially for those with a previous dengue infection, efforts have to be made to promote

[Yellow fever virus, dengue 2 and other arboviruses isolated from mosquitos, in Burkina Faso, from 1983 to 1986. Entomological and epidemiological considerations].

Science.gov (United States)

Robert, V; Lhuillier, M; Meunier, D; Sarthou, J L; Monteny, N; Digoutte, J P; Cornet, M; Germain, M; Cordellier, R

1993-01-01

An arbovirus surveillance was carried out in Burkina Faso from 1983 to 1986. It was based on crepuscular catches of mosquitoes on human bait in some wooded areas and in one town. The total collection was 228 catches with an average of 8 men per catch. The total number of mosquitoes caught was 44,956 among which 32,010 potential vector of yellow fever; all these mosquitoes were analysed for arbovirology. In the south-western part of the country (region of Bobo-Dioulasso), surveillance was conducted each year from August to November, whilst the circulation of Aedes-borne arboviruses is well known to be favoured. In 1983, 1984 and 1986, seven strains of yellow fever virus were isolated in circumstances remarkably similar. They came from selvatic areas and never from the town. They concerned only Aedes (Stegomyia) luteocephalus which is the very predominant potential vector of yellow fever in the region. They were obtained in low figure, between 1 and 4 per year. They occurred from 27th of October to 21th of November. These observations confirm that the southern portion of the Sudan savanna zone of West Africa is the setting of a customary circulation of yellow fever virus and therefore belongs to the endemic emergence zone. In 1986, two strains of dengue 2 virus were isolated. One concerned Ae. luteocephalus from the selvatic area, the other Ae. (St.) aegypti from the heart of town. These data suggest two distinct cycles for dengue 2 virus, one urban and one selvatic, which could coexist simultaneously in the same region. In the south-eastern part of the country (region of Fada-N'Gourma) a yellow fever epidemic occurred between September and December 1983; its study has enable to precise their entomological aspects. The entomological inoculation rate of yellow fever virus has been evaluated to 22 infected bites per man during the month of october, for a man living close to forest gallery. 25 strains of yellow fever virus strains was isolated from Ae. (Diceromyia

Clinical and laboratory profile of different dengue sub types in dengue virus infection

OpenAIRE

Niloy Gan Chaudhuri; S. Vithyavathi; K. Sankar

2016-01-01

Background: Dengue infection, an arthropod-borne viral hemorrhagic fever is caused by Arbovirus of Flavivirus genus and transmitted by Aedes aegypti, Aedes albopictus. Liver involvement in dengue fever is manifested by the elevation of transaminases representing reactive hepatitis, due to direct attack of virus itself or the use of hepatotoxic drugs. The objective of the study was to investigate clinical and laboratory profile of different dengue sub type's patients admitted for dengue fever....

Understanding environmental and climatic influences on regional differences and spatio-temporalscale issues of dengue fever transmission in Puerto Rico

Science.gov (United States)

Serman, E. A.; Akanda, A. S. S.; Ginsberg, H. S.; Couret, J.

2015-12-01

Each year, there are an estimated 50-100 million cases of dengue fever worldwide, roughly 30 times the number of cases as 50 years ago, with some estimates even higher. Puerto Rico (PR) has experienced epidemic dengue activity since 1963, and the disease is currently endemic. Since 1990 there have been 4 large epidemics, the most recent in 2010 where there were nearly 27,000 cases reported, amounting to almost 1% of the island's total population. Because no vaccine is currently available, effective control is dependent on our ability to understand the complex relationship between environmental factors, mosquito vector ecology, and disease epidemiology. Dengue virus is transmitted primarily by Aedes aegypti mosquitoes, as humans are the preferred host for Ae. aegypti. The purpose of our analysis is to assess temporal and spatial patterns of dengue transmission in PR and relate this to both climatic and anthropogenic factors. Unlike past studies, which have used San Juan to represent the island as a whole, our research will investigate regional dynamics in dengue transmission, as preliminary results have shown significant differences in population density, disease incidence, and environmental and climatic variables. Data from the Passive Dengue Surveillance System of CDC, meteorological observations from NCDC, and remote sensing data from USGS and NASA will be used together to identify relationships between climate, urbanization, and dengue incidence for PR at various spatial and temporal scales. Preliminary climatic factors considered include precipitation, temperature, humidity, and soil moisture. Finally, we will assess measures of urbanization such as land cover, land use, population density, and infrastructure that can make regional differences in dengue incidence each year. Results from this study could help create early warning systems for dengue surveillance in Puerto Rico, and develop techniques that can be applied to other areas of the world.

Characterization of the dengue outbreak in Nuevo Leon state, Mexico, 2010.

Science.gov (United States)

Leduc-Galindo, D; Gloria-Herrera, U; Rincón-Herrera, U; Ramos-Jiménez, J; Garcia-Luna, S; Arellanos-Soto, D; Mendoza-Tavera, N; Tavitas-Aguilar, I; Garcia-Garcia, E; Galindo-Galindo, E; Villarreal-Perez, J; Fernandez-Salas, I; Santiago, G A; Muñoz-Jordan, J; Rivas-Estilla, A M

2015-04-01

We studied serotypes circulating dengue virus (DENV) cases, entomological Breteau index, rain-fall index and epidemiology of groups affected during the 2010 outbreak in Nuevo Leon, Mexico. From 2,271 positive cases, 94% were dengue classic and 6% dengue hemorrhagic fever; DENV1 was mainly isolated (99%) (Central-American lineage of American-African-genotype). We found correlation between two environmental phenomena (Increment of rainfall and vector-indexes) (p ≤ 0.05) with epidemiological, clinical and risk of DENV-1 ongoing transmission.

Dengue situation in Brazil by year 2000

Directory of Open Access Journals (Sweden)

Hermann G Schatzmayr

2000-01-01

Full Text Available Dengue virus types 1 and 2 have been isolated in Brazil by the Department of Virology, Instituto Oswaldo Cruz, in 1986 and 1990 respectively, after many decades of absence. A successful continental Aedes aegypti control program in the Americas, has been able to eradicate the vector in most countries in the 60's, but the program could not be sustained along the years. Dengue viruses were reintroduced in the American region and the infection became endemic in Brazil, like in most Central and SouthAmerican countries and in the Caribbean region, due to the weaning of the vector control programs in these countries. High demographic densities and poor housing conditions in large urban communities, made the ideal conditions for vector spreading. All four dengue types are circulating in the continent and there is a high risk of the introduction in the country of the other two dengue types in Brazil, with the development of large epidemics. After the Cuban episode in 1981, when by the first time a large epidemic of dengue hemorrhagic fever and dengue shock syndrome have been described in the Americas, both clinical presentations are observed, specially in the countries like Brazil, with circulation of more than one dengue virus type. A tetravalent potent vaccine seems to be the only possible way to control the disease in the future, besides rapid clinical and laboratory diagnosis, in order to offer supportive treatment to the more severe clinical infections.

Evaluation of concurrent malaria and dengue infections among febrile patients

Directory of Open Access Journals (Sweden)

Parul D Shah

2017-01-01

Full Text Available Context: Despite a wide overlap between endemic areas for two important vector-borne infections, malaria and dengue, published reports of co-infections are scarce till date. Aims: To find the incidence of dengue and malaria co-infection as well as to ascertain the severity of such dengue and malaria co-infection based on clinical and haematological parameters. Setting and Design: Observational, retrospective cross-sectional study was designed including patients who consulted the tertiary care hospital of Ahmedabad seeking treatment for fever compatible with malaria and/or dengue. Subjects and Methods: A total of 8364 serum samples from clinically suspected cases of fever compatible with malaria and/or dengue were collected. All samples were tested for dengue NS-1 antigen before 5 days of onset of illness and for dengue IgM after 5 days of onset of illness. In all samples, malaria diagnosis was based on the identification of Plasmodium parasites on a thin and thick blood films microscopy. Results: Only 10.27% (859 patients with fever were tested positive for dengue and 5.1% (434 were tested positive for malaria. 3.14% (27 dengue cases show concurrent infection with malarial parasites. Hepatomegaly and jaundice 37.03% (10, haemorrhagic manifestations 18.51% (5 and kidney failure 3.7% (1, haemoglobin <12 g/dl 100% (27 and thrombocytopenia (platelet count <150,000/cmm 96.29% (26 were common in malaria and dengue co-infections and were much more common in Plasmodium falciparum infections. Conclusion: All febrile patients must be tested for malaria and dengue, both otherwise one of them will be missed in case of concurrent infections which could lead to severe diseases with complications.

Dengue Knowledge and Preventive Practices in Iquitos, Peru.

Science.gov (United States)

Paz-Soldán, Valerie A; Morrison, Amy C; Cordova Lopez, Jhonny J; Lenhart, Audrey; Scott, Thomas W; Elder, John P; Sihuincha, Moises; Kochel, Tadeusz J; Halsey, Eric S; Astete, Helvio; McCall, Philip J

2015-12-01

As part of a cluster-randomized trial to evaluate insecticide-treated curtains for dengue prevention in Iquitos, Peru, we surveyed 1,333 study participants to examine knowledge and reported practices associated with dengue and its prevention. Entomological data from 1,133 of these households were linked to the survey. Most participants knew that dengue was transmitted by mosquito bite (85.6%), but only few (18.6%) knew that dengue vectors bite during daytime. Most commonly recognized dengue symptoms were fever (86.6%), headache (76.4%), and muscle/joint pain (67.9%). Most commonly reported correct practices for mosquito control were cleaning homes (61.6%), using insecticide sprays (23%), and avoiding having standing water at home (12.3%). Higher education was associated with higher knowledge about dengue, including transmission and vector control. Higher socioeconomic status was associated with increased reported use of preventive practices requiring money expenditure. We were less likely to find Aedes aegypti eggs, larvae, or pupae in households that had dengue has been transmitted in Iquitos since the 1990s and the Regional Health Authority routinely fumigates households, treats domestic water containers with larvicide, and issues health education messages through mass media, knowledge of dengue transmission and household practices for prevention could be improved. © The American Society of Tropical Medicine and Hygiene.

Re-assess Vector Indices Threshold as an Early Warning Tool for Predicting Dengue Epidemic in a Dengue Non-endemic Country.

Directory of Open Access Journals (Sweden)

Fong-Shue Chang

Full Text Available Despite dengue dynamics being driven by complex interactions between human hosts, mosquito vectors and viruses that are influenced by climate factors, an operational model that will enable health authorities to anticipate the outbreak risk in a dengue non-endemic area has not been developed. The objectives of this study were to evaluate the temporal relationship between meteorological variables, entomological surveillance indices and confirmed dengue cases; and to establish the threshold for entomological surveillance indices including three mosquito larval indices [Breteau (BI, Container (CI and House indices (HI] and one adult index (AI as an early warning tool for dengue epidemic.Epidemiological, entomological and meteorological data were analyzed from 2005 to 2012 in Kaohsiung City, Taiwan. The successive waves of dengue outbreaks with different magnitudes were recorded in Kaohsiung City, and involved a dominant serotype during each epidemic. The annual indigenous dengue cases usually started from May to June and reached a peak in October to November. Vector data from 2005-2012 showed that the peak of the adult mosquito population was followed by a peak in the corresponding dengue activity with a lag period of 1-2 months. Therefore, we focused the analysis on the data from May to December and the high risk district, where the inspection of the immature and mature mosquitoes was carried out on a weekly basis and about 97.9% dengue cases occurred. The two-stage model was utilized here to estimate the risk and time-lag effect of annual dengue outbreaks in Taiwan. First, Poisson regression was used to select the optimal subset of variables and time-lags for predicting the number of dengue cases, and the final results of the multivariate analysis were selected based on the smallest AIC value. Next, each vector index models with selected variables were subjected to multiple logistic regression models to examine the accuracy of predicting the

Integrated Strategies for the Control and Prevention of Dengue Vectors with Particular Reference to Aedes aegypti

Directory of Open Access Journals (Sweden)

Asghar Abbas

2014-01-01

Full Text Available Dengue fever (DF is one of the most threatening vector borne diseases, affecting both humans and animals, causing severe epidemics and has brought the world to take serious steps for its control and prevention. DF is a viral disease transmitted by Aedes mosquitoes. Unfortunately, due to unavailability of vaccine and lack of effective treatment, emphasis is given on its vector control. The only option left for its eradication is to restrict mosquito breeding. This can be achieved by chemical, biological and environment management methods. Use of botanicals is also an alternate and probably most effective approach for controlling DF vector. Community based eradication campaigns including educating people about its prevention and control meseaures and personal prophylaxis also play a vital role to prevent its occurrence. Likewise, use of nanotechnology and micro-emulsion, use of pheromones, insect sterilization techniques has also shown promising results in vector control. Utilization of only one method cannot control this dangerous disease but combination of all above interventions, discussed in the present paper, may prevent the DF vector and ultimately might help in the eradication programs of this disease.

Data mining for dengue hemorrhagic fever (DHF) prediction with naive Bayes method

Science.gov (United States)

Arafiyah, Ria; Hermin, Fariani

2018-01-01

Handling of infectious diseases is determined by the accuracy and speed of diagnosis. Government through the Regulation of the Minister of Health of the Republic of Indonesia No. 82 of 2014 on the Control of Communicable Diseases establishes Dengue Hemorrhagic Fever (DHF) has made DHF prevention a national priority. Various attempts were made to overcome this misdiagnosis. The treatment and diagnosis of DHF using ANFIS has result an application program that can decide whether a patient has dengue fever or not [1]. An expert system of dengue prevention by using ANFIS has predict the weather and the number of sufferers [2]. The large number of data on DHF often cannot affect a person in making decisions. The use of data mining method, able to build data base support in decision makers diagnose DHF disease [3]. This study predicts DHF with the method of Naive Bayes. Parameter of The input variable is the patient’s medical data (temperature, spotting, bleeding, and tornuine test) and the output variable suffers from DBD or not while the system output is diagnosis of the patient suffering from DHF or not. Result of model test by using tools of Orange 3.4.5 obtained level of precision model is 77,3%.

Dengue fever and Aedes aegypti risk in the Galápagos Islands, Ecuador

OpenAIRE

Lippi, Catherine; Ibarra, Anna; Waggoner, Egan; León, Renato; Ortega, Fernando; B, Marilyn; Borbor-Cordova, Mercy; Ryan, Sadie; Nightingale, Ryan

2017-01-01

Introduction: Dengue fever is an emerging infectious disease in the Galápagos Islands of Ecuador, with the first cases reported in 2002 and periodic outbreaks since then. Here we report the results of a pilot study conducted in two cities in 2014: Puerto Ayora (PA) on Santa Cruz Island, and Puerto Baquerizo Moreno (PB) on Santa Cristobal Island. The aims of this study were to assess the social-ecological risk factors associated with dengue and mosquito presence at the household level. Methods...

Use of insecticide-treated house screens to reduce infestations of dengue virus vectors, Mexico.

Science.gov (United States)

Manrique-Saide, Pablo; Che-Mendoza, Azael; Barrera-Perez, Mario; Guillermo-May, Guillermo; Herrera-Bojorquez, Josue; Dzul-Manzanilla, Felipe; Gutierrez-Castro, Cipriano; Lenhart, Audrey; Vazquez-Prokopec, Gonzalo; Sommerfeld, Johannes; McCall, Philip J; Kroeger, Axel; Arredondo-Jimenez, Juan I

2015-02-01

Dengue prevention efforts rely on control of virus vectors. We investigated use of insecticide-treated screens permanently affixed to windows and doors in Mexico and found that the screens significantly reduced infestations of Aedes aegypti mosquitoes in treated houses. Our findings demonstrate the value of this method for dengue virus vector control.

[Modelling the effect of local climatic variability on dengue transmission in Medellin (Colombia) by means of time series analysis].

Science.gov (United States)

Rúa-Uribe, Guillermo L; Suárez-Acosta, Carolina; Chauca, José; Ventosilla, Palmira; Almanza, Rita

2013-09-01

Dengue fever is a major impact on public health vector-borne disease, and its transmission is influenced by entomological, sociocultural and economic factors. Additionally, climate variability plays an important role in the transmission dynamics. A large scientific consensus has indicated that the strong association between climatic variables and disease could be used to develop models to explain the incidence of the disease. To develop a model that provides a better understanding of dengue transmission dynamics in Medellin and predicts increases in the incidence of the disease. The incidence of dengue fever was used as dependent variable, and weekly climatic factors (maximum, mean and minimum temperature, relative humidity and precipitation) as independent variables. Expert Modeler was used to develop a model to better explain the behavior of the disease. Climatic variables with significant association to the dependent variable were selected through ARIMA models. The model explains 34% of observed variability. Precipitation was the climatic variable showing statistically significant association with the incidence of dengue fever, but with a 20 weeks delay. In Medellin, the transmission of dengue fever was influenced by climate variability, especially precipitation. The strong association dengue fever/precipitation allowed the construction of a model to help understand dengue transmission dynamics. This information will be useful to develop appropriate and timely strategies for dengue control.

Dengue viral infections

OpenAIRE

Gurugama Padmalal; Garg Pankaj; Perera Jennifer; Wijewickrama Ananda; Seneviratne Suranjith

2010-01-01

Dengue viral infections are one of the most important mosquito-borne diseases in the world. Presently dengue is endemic in 112 countries in the world. It has been estimated that almost 100 million cases of dengue fever and half a million cases of dengue hemorrhagic fever (DHF) occur worldwide. An increasing proportion of DHF is in children less than 15 years of age, especially in South East and South Asia. The unique structure of the dengue virus and the pathophysiologic responses of the host...

Health Seeking Behaviour and Treatment Intentions of Dengue and Fever: A Household Survey of Children and Adults in Venezuela.

Science.gov (United States)

Elsinga, Jelte; Lizarazo, Erley F; Vincenti, Maria F; Schmidt, Masja; Velasco-Salas, Zoraida I; Arias, Luzlexis; Bailey, Ajay; Tami, Adriana

2015-12-01

Dengue in Venezuela is a major public health problem with an increasing incidence of severe cases. Early diagnosis and timely treatment influences the outcome of dengue illness, as delay in care-seeking is significantly associated with complications leading to severe dengue. We aimed to understand patterns of health seeking behaviour (HSB) in individuals exposed to high dengue incidence in order to improve early attendance to health centres. Between September 2013 and February 2014 a cross-sectional household survey was performed in Maracay, Venezuela. Intended HSB of adults and children's parents/guardians was assessed with respect to fever or suspected dengue. Data was collected through structured questionnaires from 105 individuals. Most individuals felt at risk of dengue and believed it could be a deadly disease. In the case of suspected dengue, the majority (60%) would choose to first seek medical help versus first treating at home, in contrast to 11% in the case of fever. Amongst those who decided to visit a doctor, a suspected dengue infection would prompt them to search medical help earlier than if having only fever (p<0.001). Multivariate analysis modelling showed that the independent factors associated with the intention to firstly visit a doctor versus treating at home in the case of dengue were feeling at risk (OR = 3.29; p = 0.042) and being an adult (as opposed to caring for a child as a parent/guardian; OR = 3.33, p = 0.021), while having had a previous dengue infection (OR = 0.29; p = 0.031) and living in the neighbourhood Caña de Azúcar (OR = 0.28, p = 0.038) were negatively associated with seeking medical care as their first action. Knowledge of HSB related to dengue is scarce in the Americas, our study attempts to contribute to a better understanding of HSB in this region. Improving early dengue disease recognition and awareness may enhance prompt attendance to medical care in affected populations and thereby reduce mortality and severity of

El Niño-Southern Oscillation and dengue early warning in Ecuador

Science.gov (United States)

Stewart, A. M.; Lowe, R.

2012-04-01

Dengue fever, a mosquito-borne viral disease, is one of the most important emerging tropical diseases. Dengue is hyper-endemic in coastal Ecuador, where all four serotypes co-circulate. The El Niño-Southern Oscillation (ENSO) influences climate in Ecuador, with positive phase ENSO (El Niño) associated with wetter and warmer conditions over the southern coastal region. In turn, greater rainfall increases the availability of mosquito breeding sites for the dengue mosquito (Aedes aegypti), while warmer temperatures increase rates of larval development, mosquito biting, and viral replication in the mosquito. We report a statistical model for assessing the importance of climate as a driver for inter-annual variability in dengue fever in southern coastal Ecuador. Climate variables from a local meteorology station (precipitation, number of rainy days, minimum/maximum/mean air temperature), combined with gridded climate products, and anomalies of Pacific sea surface temperatures (Oceanic Niño Index, ONI) were used to predict monthly dengue standardized morbidity ratios (SMR) (1995-2010). Non-climatic confounding factors such as serotype introduction and vector control effort were also considered. Preliminary results indicated a statistically significant positive association between dengue risk and the number of rainy days during the previous month. Both the number of rainy days and dengue SMR were positively associated with the Pacific SST anomalies with a lead time of several months. Due to time lags involved in the climate-disease transmission system, monitoring El Niño / La Niña evolution in the Pacific Ocean could provide some predictive lead time for forecasting dengue epidemics. This is the first study of dengue fever and climate in this region. This research provides the foundation to develop a climate-driven early warning system for dengue fever in Ecuador.

Ecg manifestations in dengue infection

International Nuclear Information System (INIS)

Tarique, S.; Murtaza, G.; Asif, S.; Qureshi, I.H.

2013-01-01

To determine the frequency of ECG changes in patients with dengue fever and dengue hemorrhagic fever. Place of study: Department of Medicine, Mayo Hospital Lahore Duration of study: September to November 201 Study design: Cross sectional analytical study Patient and methods: 116 patients with dengue infection were enrolled in the study. Their clinical presentation and examination was duly noted. Each patient had baseline and then regular monitoring of blood counts, metabolic profile and fluid status. Patients with Dengue Hemorrhagic fever underwent radiological examination in form of chest radiograph and ultrasound abdomen. ECG was carried out in all patients. Results: Out of 116 patients, 61(52.6%) suffered from Dengue Fever and 55(47.4%) had Dengue Hemorrhagic Fever. Overall 78 patients had normal ECG. Abnormal ECG findings like tachycardia, bradycardia, supraventricular tachycardia, left bundle branch block, ST depression, poor progression of R wave were noted. There was no significant relationship of ECG findings with the disease. Conclusion: ECG changes can occur in dengue infection with or without cardiac symptoms. Commonly noted findings were ST depression and bradycardia. (author)

Assessment of Dengue Fever Severity Through Liver Function Tests

International Nuclear Information System (INIS)

Ahmed, A.; Alvi, A. H.; Nawaz, A. A.; Butt, A.; Hanif, A.

2014-01-01

Objective: To assess the utility of liver function tests (LFTs) for early recognition and prediction of severity of Dengue fever in hospitalized patients. Study Design: An analytical study. Place and Duration of Study: Services Institute of Medical Science and Fatima Memorial Hospital, Lahore, from September - December 2010. Methodology: Admitted cases of Dengue fever were divided into 3 groups; mild, moderate and severe increases in aminotransferases. Elevation in LFTs was co-related with good or bad outcome i.e. (survival or complication free stay) or (death or complications). Results were analyzed in SPSS version 18. Results: Out of the 353 patients with mean age of 37.12 +- 15.45 years, 245 (69.4%) were males and 108 (30.6%) were females. Seventy five patients (21.2%) had mild elevation of aminotransferases (2 fold increases), 265 patients (75.1%) had moderate increases (3 to 4 fold) and 13 (3.7%) had severe (> 4 fold increase). ALT was statistically higher in patients with septicemia, hepatic and renal failure (p-value 0.05). AST was higher in almost all complications. Prolonged hospital stay was associated with raised LFTs and greater complications and mortality. AST was found to be twice as much raised as ALT. Conclusion: AST and ALT were statistically higher in patients with worse outcome thus can lead to early recognition of high risk cases. (author)

PCA-MLP SVM distinction of salivary Raman spectra of dengue fever infection.

Science.gov (United States)

Radzol, A R M; Lee, Khuan Y; Mansor, W; Wong, P S; Looi, I

2017-07-01

Dengue fever (DF) is a disease of major concern caused by flavivirus infection. Delayed diagnosis leads to severe stages, which could be deadly. Of recent, non-structural protein (NS1) has been acknowledged as a biomarker, alternative to immunoglobulins for early detection of dengue in blood. Further, non-invasive detection of NS1 in saliva makes the approach more appealing. However, since its concentration in saliva is less than blood, a sensitive and specific technique, Surface Enhanced Raman Spectroscopy (SERS), is employed. Our work here intends to define an optimal PCA-SVM (Principal Component Analysis-Support Vector Machine) with Multilayer Layer Perceptron (MLP) kernel model to distinct between positive and negative NS1 infected samples from salivary SERS spectra, which, to the best of our knowledge, has never been explored. Salivary samples of DF positive and negative subjects were collected, pre-processed and analyzed. PCA and SVM classifier were then used to differentiate the SERS analyzed spectra. Since performance of the model depends on the PCA criterion and MLP parameters, both are examined in tandem. Its performance is also compared to our previous works on simulated NS1 salivary samples. It is found that the best PCA-SVM (MLP) model can be defined by 95 PCs from CPV criterion with P1 and P2 values of 0.01 and -0.2 respectively. A classification performance of [76.88%, 85.92%, 67.83%] is achieved.

A community-based prospective cohort study of dengue viral infection in Malaysia: the study protocol.

Science.gov (United States)

Jahan, Nowrozy Kamar; Ahmad, Mohtar Pungut; Dhanoa, Amreeta; Meng, Cheong Yuet; Ming, Lau Wee; Reidpath, Daniel D; Allotey, Pascale; Zaini, Anuar; Phipps, Maude Elvira; Fatt, Quek Kia; Rabu, Aman Bin; Sirajudeen, Rowther; Fatan, Ahmad AbdulBasitz Ahmad; Ghafar, Faidzal Adlee; Ahmad, Hamdan Bin; Othman, Iekhsan; SyedHassan, Sharifah

2016-08-11

Globally, dengue infections constitute a significant public health burden. In recent decades, Malaysia has become a dengue hyper-endemic country with the co-circulation of the four dengue virus serotypes. The cyclical dominance of sub-types contributes to a pattern of major outbreaks. The consequences can be observed in the rising incidence of reported dengue cases and dengue related deaths. Understanding the complex interaction of the dengue virus, its human hosts and the mosquito vectors at the community level may help develop strategies for addressing the problem. A prospective cohort study will be conducted in Segamat district of Johor State in Peninsular Malaysia. Researchers received approval from the Malaysian Medical Research Ethics Committee and Monash University Human Research Ethics Committee. The study will be conducted at a Malaysian based health and demographic surveillance site over a 1 year period in three different settings (urban, semi-urban and rural). The study will recruit healthy adults (male and female) aged 18 years and over, from three ethnic groups (Malay, Chinese and Indian). The sample size calculated using the Fleiss method with continuity correction is 333. Sero-surveillance of participants will be undertaken to identify asymptomatic, otherwise healthy cases; cases with dengue fever who are managed as out-patients; and cases with dengue fever admitted to a hospital. A genetic analysis of the participants will be undertaken to determine whether there is a relationship between genetic predisposition and disease severity. A detailed medical history, past history of dengue infection, vaccination history against other flaviviruses such as Japanese encephalitis and Yellow fever, and the family history of dengue infection will also be collected. In addition, a mosquito surveillance will be carried out simultaneously in recruitment areas to determine the molecular taxonomy of circulating vectors. The research findings will estimate the burden

Local and global effects of climate on dengue transmission in Puerto Rico.

Directory of Open Access Journals (Sweden)

Michael A Johansson

Full Text Available The four dengue viruses, the agents of dengue fever and dengue hemorrhagic fever in humans, are transmitted predominantly by the mosquito Aedes aegypti. The abundance and the transmission potential of Ae. aegypti are influenced by temperature and precipitation. While there is strong biological evidence for these effects, empirical studies of the relationship between climate and dengue incidence in human populations are potentially confounded by seasonal covariation and spatial heterogeneity. Using 20 years of data and a statistical approach to control for seasonality, we show a positive and statistically significant association between monthly changes in temperature and precipitation and monthly changes in dengue transmission in Puerto Rico. We also found that the strength of this association varies spatially, that this variation is associated with differences in local climate, and that this relationship is consistent with laboratory studies of the impacts of these factors on vector survival and viral replication. These results suggest the importance of temperature and precipitation in the transmission of dengue viruses and suggest a reason for their spatial heterogeneity. Thus, while dengue transmission may have a general system, its manifestation on a local scale may differ from global expectations.

Dengue NS1 Antigen - for Early Detection of Dengue Virus Infection

Directory of Open Access Journals (Sweden)

Amol Hartalkar

2015-08-01

Full Text Available Objectives: To evaluate the efficacy of NS1 antigen assay for early diagnosis of dengue virus infection in a tertiary care hospital. Methods: This cross sectional study was carried out in department of Medicine from August to December 2013. Total 100 patients with dengue fever were included. Complete blood count, alanine aminotransferase (ALT, aspartate aminotransferase (AST, Dengue NS1 antigen and IgM and IgG antibodies of dengue virus were done in all cases. Results: Of the 100 sera tested, 75% were positive for dengue virus infection based on dengue NS1 antigen, IgM antibody and IgG antibody. Dengue NS1 antigen and IgM, IgG antibody were able to detect dengue virus infection between day 1 to day 8 in 92% of samples, 86.7% of samples and 82.6% of samples respectively. Sixty nine percent (69% were found positive for dengue NS1 antigen, 65% were IgM positive and 62% were IgG positive. Based on the dengue NS1 antigen and IgM antibody combination, 74% were positive for dengue virus infections. Sensitivity of Dengue NS1 antigen was 92.3% and specificity of 74.28% in comparison to IgM antibody. Detection rate increased to 75%, based on the antigen and IgG antibody combination. Sensitivity of dengue NS1 antigen was 90.3% and specificity of 65.8% in comparison to IgG antibody. Conclusion: Dengue NS1 antigen is a useful, sensitive and specific test for early diagnosis of dengue virus infection and it improves diagnostic efficiency in combination with antibody test. Key words: Dengue fever, NS1 antigen. Introduction: Dengue fever (DF is the most common arboviral illness in humans. Each year, an estimated 50-100 million cases of dengue fever and 500,000 cases of dengue hemorrhagic fever occur worldwide, with 30000 deaths (mainly in children. Globally 2.5-3 billion people in approximately 112 tropical and subtropical countries are at risk of dengue.of samples respectively. Sixty nine percent (69% were found positive for dengue NS1 antigen, 65% were Ig

Mapping intra-urban transmission risk of dengue fever with big hourly cellphone data.

Science.gov (United States)

Mao, Liang; Yin, Ling; Song, Xiaoqing; Mei, Shujiang

2016-10-01

Cellphone tracking has been recently integrated into risk assessment of disease transmission, because travel behavior of disease carriers can be depicted in unprecedented details. Still in its infancy, such an integration has been limited to: 1) risk assessment only at national and provincial scales, where intra-urban human movements are neglected, and 2) using irregularly logged cellphone data that miss numerous user movements. Furthermore, few risk assessments have considered positional uncertainty of cellphone data. This study proposed a new framework for mapping intra-urban disease risk with regularly logged cellphone tracking data, taking the dengue fever in Shenzhen city as an example. Hourly tracking records of 5.85 million cellphone users, combined with the random forest classification and mosquito activities, were utilized to estimate the local transmission risk of dengue fever and the importation risk through travels. Stochastic simulations were further employed to quantify the uncertainty of risk. The resultant maps suggest targeted interventions to maximally reduce dengue cases exported to other places, as well as appropriate interventions to contain risk in places that import them. Given the popularity of cellphone use in urbanized areas, this framework can be adopted by other cities to design spatio-temporally resolved programs for disease control. Copyright © 2016 Elsevier B.V. All rights reserved.

International team with Virginia Tech participation maps genome of dengue and yellow fever mosquito

OpenAIRE

Trulove, Susan

2007-01-01

Developing new strategies to prevent and control yellow fever and dengue fever has become more possible with the completion of the first draft of the genome sequence of Aedes aegypti mosquito by scientists led by Vishvanath Nene at The Institute for Genomic Research (TIGR) and David Severson at the University of Notre Dame. The genome is the complete set of genetic material including genes and other segments of DNA in an organism.

CD8+ T lymphocyte expansion, proliferation and activation in dengue fever.

Directory of Open Access Journals (Sweden)

Andréia Manso de Matos

2015-02-01

Full Text Available Dengue fever induces a robust immune response, including massive T cell activation. The level of T cell activation may, however, be associated with more severe disease. In this study, we explored the level of CD8+ T lymphocyte activation in the first six days after onset of symptoms during a DENV2 outbreak in early 2010 on the coast of São Paulo State, Brazil. Using flow cytometry we detected a progressive increase in the percentage of CD8+ T cells in 74 dengue fever cases. Peripheral blood mononuclear cells from 30 cases were thawed and evaluated using expanded phenotyping. The expansion of the CD8+ T cells was coupled with increased Ki67 expression. Cell activation was observed later in the course of disease, as determined by the expression of the activation markers CD38 and HLA-DR. This increased CD8+ T lymphocyte activation was observed in all memory subsets, but was more pronounced in the effector memory subset, as defined by higher CD38 expression. Our results show that most CD8+ T cell subsets are expanded during DENV2 infection and that the effector memory subset is the predominantly affected sub population.

Dengue and Severe Dengue

Science.gov (United States)

... all regions of WHO in recent years. Dengue virus is transmitted by female mosquitoes mainly of the species Aedes aegypti and, to a lesser extent, Ae. albopictus . This mosquito also transmits chikungunya, yellow fever and Zika infection. Dengue is widespread throughout the tropics, with ...

Epidemiologi dan Diagnosis Dengue di Indonesia

OpenAIRE

Zilhadia, Zilhadia

2007-01-01

Dengue fever/DF and dengue hemorrhagic fever/DHF is a global public health problem that occured in tropical and subtropical region. Epidemic dengue occurs every years, and it continues to be a major health problem in Indonesia. Due to its asymptomatic nature, a reliable, rapid and accurate dengue diagnosis is needed. Dengue diagnosis method based on molecular dengue virus properties and it will be developed by researcher. Dengue rapid test isnewly method. This article explaine about dengue ep...

Dengue Contingency Planning: From Research to Policy and Practice

Science.gov (United States)

Runge-Ranzinger, Silvia; Kroeger, Axel; Olliaro, Piero; McCall, Philip J.; Sánchez Tejeda, Gustavo; Lloyd, Linda S.; Hakim, Lokman; Bowman, Leigh R.; Horstick, Olaf; Coelho, Giovanini

2016-01-01

Background Dengue is an increasingly incident disease across many parts of the world. In response, an evidence-based handbook to translate research into policy and practice was developed. This handbook facilitates contingency planning as well as the development and use of early warning and response systems for dengue fever epidemics, by identifying decision-making processes that contribute to the success or failure of dengue surveillance, as well as triggers that initiate effective responses to incipient outbreaks. Methodology/Principal findings Available evidence was evaluated using a step-wise process that included systematic literature reviews, policymaker and stakeholder interviews, a study to assess dengue contingency planning and outbreak management in 10 countries, and a retrospective logistic regression analysis to identify alarm signals for an outbreak warning system using datasets from five dengue endemic countries. Best practices for managing a dengue outbreak are provided for key elements of a dengue contingency plan including timely contingency planning, the importance of a detailed, context-specific dengue contingency plan that clearly distinguishes between routine and outbreak interventions, surveillance systems for outbreak preparedness, outbreak definitions, alert algorithms, managerial capacity, vector control capacity, and clinical management of large caseloads. Additionally, a computer-assisted early warning system, which enables countries to identify and respond to context-specific variables that predict forthcoming dengue outbreaks, has been developed. Conclusions/Significance Most countries do not have comprehensive, detailed contingency plans for dengue outbreaks. Countries tend to rely on intensified vector control as their outbreak response, with minimal focus on integrated management of clinical care, epidemiological, laboratory and vector surveillance, and risk communication. The Technical Handbook for Surveillance, Dengue Outbreak

Improved dengue fever prevention through innovative intervention methods in the city of Salto, Uruguay.

Science.gov (United States)

Basso, César; García da Rosa, Elsa; Romero, Sonnia; González, Cristina; Lairihoy, Rosario; Roche, Ingrid; Caffera, Ruben M; da Rosa, Ricardo; Calfani, Marisel; Alfonso-Sierra, Eduardo; Petzold, Max; Kroeger, Axel; Sommerfeld, Johannes

2015-02-01

Uruguay is located at the southern border of Aedes aegypti distribution on the South American sub-continent. The reported dengue cases in the country are all imported from surrounding countries. One of the cities at higher risk of local dengue transmission is Salto, a border city with heavy traffic from dengue endemic areas. We completed an intervention study using a cluster randomized trial design in 20 randomly selected 'clusters' in Salto. The clusters were located in neighborhoods of differing geography and economic, cultural and social aspects. Entomological surveys were carried out to measure the impact of the intervention on vector densities. Through participatory processes of all stakeholders, an appropriate ecosystem management intervention was defined. Residents collected the abundant small water holding containers and the Ministry of Public Health and the Municipality of Salto were responsible for collecting and eliminating them. Additional vector breeding places were large water tanks; they were either altered so that they could not hold water any more or covered so that oviposition by mosquitoes could not take place. The response from the community and national programme managers was encouraging. The intervention evidenced opportunities for cost savings and reducing dengue vector densities (although not to statistically significant levels). The observed low vector density limits the potential reduction due to the intervention. A larger sample size is needed to obtain a statistically significant difference. © The author 2015. The World Health Organization has granted Oxford University Press permission for the reproduction of this article.

Retroperitoneal Haematoma in a Patient with Dengue Haemorrhagic Fever: A Rare Case Report.

Science.gov (United States)

Singh, Jasminder; Singh, Harpreet; Sukhija, Gagandeep; Jagota, Ruchi; Bala, Saroj

2016-11-01

Dengue Haemorrhagic Fever (DHF) has diverse manifestations ranging from asymptomatic petechial skin haemorrhages to life threatening cerebral, pulmonary, gastrointestinal and genitourinary haemorrhages. However, the association of spontaneous retroperitoneal haematomas with DHF is not well documented in literature. We report a rare case of spontaneous retroperitoneal haematoma complicating DHF.

Viruses vector control proposal: genus Aedes emphasis

Directory of Open Access Journals (Sweden)

Nelson Nogueira Reis

2017-07-01

Full Text Available The dengue fever is a major public health problem in the world. In Brazil, in 2015, there were 1,534,932 cases, being 20,320 cases of severe form, and 811 deaths related to this disease. The distribution of Aedes aegypti, the vector, is extensive. Recently, Zika and Chikungunya viruses had arisen, sharing the same vector as dengue and became a huge public health issue. Without specific treatment, it is urgently required as an effective vector control. This article is focused on reviewing vector control strategies, their effectiveness, viability and economical impact. Among all, the Sterile Insect Technique is highlighted as the best option to be adopted in Brazil, once it is largely effectively used in the USA and Mexico for plagues related to agribusiness.

Synchrony of sylvatic dengue isolations: a multi-host, multi-vector SIR model of dengue virus transmission in Senegal.

Directory of Open Access Journals (Sweden)

Benjamin M Althouse

Full Text Available Isolations of sylvatic dengue-2 virus from mosquitoes, humans and non-human primates in Senegal show synchronized multi-annual dynamics over the past 50 years. Host demography has been shown to directly affect the period between epidemics in other pathogen systems, therefore, one might expect unsynchronized multi-annual cycles occurring in hosts with dramatically different birth rates and life spans. However, in Senegal, we observe a single synchronized eight-year cycle across all vector species, suggesting synchronized dynamics in all vertebrate hosts. In the current study, we aim to explore two specific hypotheses: 1 primates with different demographics will experience outbreaks of dengue at different periodicities when observed as isolated systems, and that coupling of these subsystems through mosquito biting will act to synchronize incidence; and 2 the eight-year periodicity of isolations observed across multiple primate species is the result of long-term cycling in population immunity in the host populations. To test these hypotheses, we develop a multi-host, multi-vector Susceptible, Infected, Removed (SIR model to explore the effects of coupling multiple host-vector systems of dengue virus transmission through cross-species biting rates. We find that under small amounts of coupling, incidence in the host species synchronize. Long-period multi-annual dynamics are observed only when prevalence in troughs reaches vanishingly small levels (< 10(-10, suggesting that these dynamics are inconsistent with sustained transmission in this setting, but are consistent with local dengue virus extinctions followed by reintroductions. Inclusion of a constant introduction of infectious individuals into the system causes the multi-annual periods to shrink, while the effects of coupling remain the same. Inclusion of a stochastic rate of introduction allows for multi-annual periods at a cost of reduced synchrony. Thus, we conclude that the eight-year period

Assessment of risk of dengue and yellow fever virus transmission in three major Kenyan cities based on Stegomyia indices

Science.gov (United States)

Tchouassi, David P.; Bastos, Armanda D. S.; Sang, Rosemary

2017-01-01

Dengue (DEN) and yellow fever (YF) are re-emerging in East Africa, with contributing drivers to this trend being unplanned urbanization and increasingly adaptable anthropophilic Aedes (Stegomyia) vectors. Entomological risk assessment of these diseases remains scarce for much of East Africa and Kenya even in the dengue fever-prone urban coastal areas. Focusing on major cities of Kenya, we compared DEN and YF risk in Kilifi County (DEN-outbreak-prone), and Kisumu and Nairobi Counties (no documented DEN outbreaks). We surveyed water-holding containers for mosquito immature (larvae/pupae) indoors and outdoors from selected houses during the long rains, short rains and dry seasons (100 houses/season) in each County from October 2014-June 2016. House index (HI), Breteau index (BI) and Container index (CI) estimates based on Aedes (Stegomyia) immature infestations were compared by city and season. Aedes aegypti and Aedes bromeliae were the main Stegomyia species with significantly more positive houses outdoors (212) than indoors (88) (n = 900) (χ2 = 60.52, P < 0.0001). Overall, Ae. aegypti estimates of HI (17.3 vs 11.3) and BI (81.6 vs 87.7) were higher in Kilifi and Kisumu, respectively, than in Nairobi (HI, 0.3; BI,13). However, CI was highest in Kisumu (33.1), followed by Kilifi (15.1) then Nairobi (5.1). Aedes bromeliae indices were highest in Kilifi, followed by Kisumu, then Nairobi with HI (4.3, 0.3, 0); BI (21.3, 7, 0.7) and CI (3.3, 3.3, 0.3), at the respective sites. HI and BI for both species were highest in the long rains, compared to the short rains and dry seasons. We found strong positive correlations between the BI and CI, and BI and HI for Ae. aegypti, with the most productive container types being jerricans, drums, used/discarded containers and tyres. On the basis of established vector index thresholds, our findings suggest low-to-medium risk levels for urban YF and high DEN risk for Kilifi and Kisumu, whereas for Nairobi YF risk was low while DEN risk

Assessment of risk of dengue and yellow fever virus transmission in three major Kenyan cities based on Stegomyia indices.

Directory of Open Access Journals (Sweden)

Sheila B Agha

2017-08-01

Full Text Available Dengue (DEN and yellow fever (YF are re-emerging in East Africa, with contributing drivers to this trend being unplanned urbanization and increasingly adaptable anthropophilic Aedes (Stegomyia vectors. Entomological risk assessment of these diseases remains scarce for much of East Africa and Kenya even in the dengue fever-prone urban coastal areas. Focusing on major cities of Kenya, we compared DEN and YF risk in Kilifi County (DEN-outbreak-prone, and Kisumu and Nairobi Counties (no documented DEN outbreaks. We surveyed water-holding containers for mosquito immature (larvae/pupae indoors and outdoors from selected houses during the long rains, short rains and dry seasons (100 houses/season in each County from October 2014-June 2016. House index (HI, Breteau index (BI and Container index (CI estimates based on Aedes (Stegomyia immature infestations were compared by city and season. Aedes aegypti and Aedes bromeliae were the main Stegomyia species with significantly more positive houses outdoors (212 than indoors (88 (n = 900 (χ2 = 60.52, P < 0.0001. Overall, Ae. aegypti estimates of HI (17.3 vs 11.3 and BI (81.6 vs 87.7 were higher in Kilifi and Kisumu, respectively, than in Nairobi (HI, 0.3; BI,13. However, CI was highest in Kisumu (33.1, followed by Kilifi (15.1 then Nairobi (5.1. Aedes bromeliae indices were highest in Kilifi, followed by Kisumu, then Nairobi with HI (4.3, 0.3, 0; BI (21.3, 7, 0.7 and CI (3.3, 3.3, 0.3, at the respective sites. HI and BI for both species were highest in the long rains, compared to the short rains and dry seasons. We found strong positive correlations between the BI and CI, and BI and HI for Ae. aegypti, with the most productive container types being jerricans, drums, used/discarded containers and tyres. On the basis of established vector index thresholds, our findings suggest low-to-medium risk levels for urban YF and high DEN risk for Kilifi and Kisumu, whereas for Nairobi YF risk was low while DEN risk

Fever versus Fever: the role of host and vector susceptibility and interspecific competition in shaping the current and future distributions of the sylvatic cycles of dengue virus and yellow fever virus

Science.gov (United States)

Hanley, Kathryn A.; Monath, Thomas P.; Weaver, Scott C.; Rossi, Shannan L.; Richman, Rebecca L.; Vasilakis, Nikos

2013-01-01

Two different species of flaviviruses, dengue virus (DENV) and yellow fever virus (YFV), that originated in sylvatic cycles maintained in non-human primates and forest-dwelling mosquitoes have emerged repeatedly into sustained human-to-human transmission by Aedes aegypti mosquitoes. Sylvatic cycles of both viruses remain active, and where the two viruses overlap in West Africa they utilize similar suites of monkeys and Aedes mosquitoes. These extensive similarities render the differences in the biogeography and epidemiology of the two viruses all the more striking. First, the sylvatic cycle of YFV originated in Africa and was introduced into the New World, probably as a result of the slave trade, but is absent in Asia; in contrast, sylvatic DENV likely originated in Asia and has spread to Africa but not to the New World. Second, while sylvatic YFV can emerge into extensive urban outbreaks in humans, these invariably die out, whereas four different types of DENV have established human transmission cycles that are ecologically and evolutionarily distinct from their sylvatic ancestors. Finally, transmission of YFV among humans has been documented only in Africa and the Americas, whereas DENV is transmitted among humans across most of the range of competent Aedes vectors, which in the last decade has included every continent save Antarctica. This review summarizes current understanding of sylvatic transmission cycles of YFV and DENV, considers possible explanations for their disjunct distributions, and speculates on the potential consequences of future establishment of a sylvatic cycle of DENV in the Americas. PMID:23523817

Dengue-associated kidney disease.