Feldmann, Heinz; Geisbert, Thomas W
2012-01-01
Ebola viruses are the causative agents of a severe form of viral haemorrhagic fever in man, designated Ebola haemorrhagic fever, and are endemic in regions of central Africa. The exception is the species Reston Ebola virus, which has not been associated with human disease and is found in the Philippines. Ebola virus constitutes an important local public health threat in Africa, with a worldwide effect through imported infections and through the fear of misuse for biological terrorism. Ebola virus is thought to also have a detrimental effect on the great ape population in Africa. Case-fatality rates of the African species in man are as high as 90%, with no prophylaxis or treatment available. Ebola virus infections are characterised by immune suppression and a systemic inflammatory response that causes impairment of the vascular, coagulation, and immune systems, leading to multiorgan failure and shock, and thus, in some ways, resembling septic shock. PMID:21084112
Crimean-Congo haemorrhagic fever virus infection in birds: field investigations in Senegal.
Zeller, H G; Cornet, J P; Camicas, J L
1994-01-01
In Senegal, wild ground-feeding birds are frequently infested with immature ticks. In two areas where numerous Crimean-Congo haemorrhagic fever (CCHF) virus isolations were obtained from Hyalomma marginatum rufipes adult ticks collected on ungulates, 175 birds were captured and sera collected. CCHF antibodies were detected by ELISA in 6/22 red-beaked hornbills (Tockus erythrorhynchus), 2/11 glossy starlings (Lamprotornis sp.) and 1/3 guinea fowls. The virus was isolated from H. m. rufipes nymphs collected on a hornbill. The role of wild ground-feeding birds in CCHF virus ecology in West Africa is discussed.
Marburg haemorrhagic fever: A rare but fatal disease
African Journals Online (AJOL)
The causative virus is the Marburgvirus of the Filoviridae family. The disease is clinically indistinguishable from Ebola haemorrhagic fever though the latter's causative agent is unrelated. Transmission of the Marburgvirus is via close contact with blood or other body fluids (faeces, vomitus, urine and respiratory secretions) ...
Directory of Open Access Journals (Sweden)
Laura C Bonney
2017-10-01
Full Text Available Crimean-Congo Haemorrhagic fever Virus (CCHFV is a rapidly emerging vector-borne pathogen and the cause of a virulent haemorrhagic fever affecting large parts of Europe, Africa, the Middle East and Asia.An isothermal recombinase polymerase amplification (RPA assay was successfully developed for molecular detection of CCHFV. The assay showed rapid (under 10 minutes detection of viral extracts/synthetic virus RNA of all 7 S-segment clades of CCHFV, with high target specificity. The assay was shown to tolerate the presence of inhibitors in crude preparations of mock field samples, indicating that this assay may be suitable for use in the field with minimal sample preparation. The CCHFV RPA was successfully used to screen and detect CCHFV positives from a panel of clinical samples from Tajikistan.The assay is a rapid, isothermal, simple-to-perform molecular diagnostic, which can be performed on a light, portable real-time detection device. It is ideally placed therefore for use as a field-diagnostic or in-low resource laboratories, for monitoring of CCHF outbreaks at the point-of-need, such as in remote rural regions in affected countries.
DEFF Research Database (Denmark)
Gharabaghi, Mehrnaz Asadi; Chinikar, Sadegh; Ghiasi, Seyyed Mojtaba
2011-01-01
Crimean-Congo haemorrhagic fever (CCHF) is a tickborne viral zoonosis with up to 50% mortality in humans caused by CCHF virus belonging to the genus Nairovirus, family Bunyaviridae. The geographical distribution of CCHF cases corresponds closely with the distribution of principle tick vectors...... that is species of Hyaloma. The disease presents with non-specific febrile symptoms, but progress to a serious haemorrhagic syndrome that, soon after, a full blown multi organ failure may develop with prominent features of liver damage and bleeding diathesis. The authors present a case of a 39-year-old man...
Crimean-Congo haemorrhagic fever virus in Kazakhstan (1948-2013).
Nurmakhanov, Talgat; Sansyzbaev, Yerlan; Atshabar, Bakhyt; Deryabin, Pavel; Kazakov, Stanislav; Zholshorinov, Aitmagambet; Matzhanova, Almagul; Sadvakassova, Alya; Saylaubekuly, Ratbek; Kyraubaev, Kakimzhan; Hay, John; Atkinson, Barry; Hewson, Roger
2015-09-01
Crimean-Congo haemorrhagic fever (CCHF) is a pathogenic and often fatal arboviral disease with a distribution spanning large areas of Africa, Europe and Asia. The causative agent is a negative-sense single-stranded RNA virus classified within the Nairovirus genus of the Bunyaviridae family. Cases of CCHF have been officially recorded in Kazakhstan since the disease was first officially reported in modern medicine. Serological surveillance of human and animal populations provide evidence that the virus was perpetually circulating in a local enzoonotic cycle involving mammals, ticks and humans in the southern regions of the country. Most cases of human disease were associated with agricultural professions such as farming, shepherding and fruit-picking; the typical route of infection was via tick-bite although several cases of contact transmission associated with caring for sick patients have been documented. In total, 704 confirmed human cases of CCHF have been registered in Kazakhstan from 1948-2013 with an overall case fatality rate of 14.8% for cases with a documented outcome. The southern regions of Kazakhstan should be considered endemic for CCHF with cases reported from these territories on an annual basis. Modern diagnostic technologies allow for rapid clinical diagnosis and for surveillance studies to monitor for potential expansion in known risk areas. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
Lumley, S; Atkinson, B; Dowall, Sd; Pitman, Jk; Staplehurst, S; Busuttil, J; Simpson, Aj; Aarons, Ej; Petridou, C; Nijjar, M; Glover, S; Brooks, Tj; Hewson, R
2014-07-31
Crimean-Congo haemorrhagic fever (CCHF) was diagnosed in a United Kingdom traveller who returned from Bulgaria in June 2014. The patient developed a moderately severe disease including fever, headaches and petechial rash. CCHF was diagnosed following identification of CCHF virus (CCHFV) RNA in a serum sample taken five days after symptom onset. Sequence analysis of the CCHFV genome showed that the virus clusters within the Europe 1 clade, which includes viruses from eastern Europe.
A Q fever case mimicking crimean-congo haemorrhagic fever
Directory of Open Access Journals (Sweden)
O Karabay
2011-01-01
Full Text Available Coxiella burnetii is the bacterium that causes Q fever. Human infection is mainly transmitted from cattle, goats and sheep. The disease is usually self-limited. Pneumonia and hepatitis are the most common clinical manifestations. In this study, we present a case of Q fever from the western part of Turkey mimicking Crimean-Congo haemorrhagic fever (CCHF in terms of clinical and laboratory findings.
Progress towards the treatment of Ebola haemorrhagic fever.
Ströher, Ute; Feldmann, Heinz
2006-12-01
Being highly pathogenic for human and nonhuman primates and the subject of former weapon programmes makes Ebola virus one of the most feared pathogens worldwide today. Due to a lack of licensed pre- and postexposure intervention, the current response depends on rapid diagnostics, proper isolation procedures and supportive care of case patients. Consequently, the development of more specific countermeasures is of high priority for the preparedness of many nations. Over the past years, enhanced research efforts directed to better understand virus replication and pathogenesis have identified potential new targets for intervention strategies. The authors discuss the most promising therapeutic approaches for Ebola haemorrhagic fever as judged by their efficacy in animal models. The current development in this field encourages discussions on how to move some of the experimental approaches towards clinical application.
Impact of Climate on the incidence of Dengue Haemorrhagic fever in Semarang City
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.
Viral haemorrhagic fever and vascular alterations.
Aleksandrowicz, P; Wolf, K; Falzarano, D; Feldmann, H; Seebach, J; Schnittler, H
2008-02-01
Pathogenesis of viral haemorrhagic fever (VHF) is closely associated with alterations of the vascular system. Among the virus families causing VHF, filoviruses (Marburg and Ebola) are the most fatal, and will be focused on here. After entering the body, Ebola primarily targets monocytes/macrophages and dendritic cells. Infected dendritic cells are largely impaired in their activation potency, likely contributing to the immune suppression that occurs during filovirus infection. Monocytes/macrophages, however, immediately activate after viral contact and release reasonable amounts of cytokines that target the vascular system, particularly the endothelial cells. Some underlying molecular mechanisms such as alteration of the vascular endothelial cadherin/catenin complex, tyrosine phosphorylation, expression of cell adhesion molecules, tissue factor and the effect of soluble viral proteins released from infected cells to the blood stream will be discussed.
Viral Haemorrhagic Septicaemia Virus
DEFF Research Database (Denmark)
Olesen, Niels Jørgen; Skall, Helle Frank
2013-01-01
This chapter covers the genetics (genotypes and serotypes), clinical signs, host species, transmission, prevalence, diagnosis, control and prevention of viral haemorrhagic septicaemia virus.......This chapter covers the genetics (genotypes and serotypes), clinical signs, host species, transmission, prevalence, diagnosis, control and prevention of viral haemorrhagic septicaemia virus....
DEFF Research Database (Denmark)
Chinikar, S; Ghiasi, Seyed Mojtaba; Mojtaba Ghiasi, S
2010-01-01
Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with a high mortality rate in humans. The CCHF virus is transmitted to humans through the bite of Ixodid ticks or contact with blood or tissues of CCHF patients or infected livestock. In December 2008, a re-emerging outbreak...... of CCHF occurred in the southern part of Iran. Five people were hospitalised with sudden fever and haemorrhaging, and CCHF was confirmed by RT-PCR and serological assays. One of the cases had a fulminant course and died. Livestock was identified as the source of infection; all animals in the incriminated...
Dengue fever and dengue haemorrhagic fever in adolescents and adults.
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.
Nutritional management in Ebola haemorrhagic fever
Directory of Open Access Journals (Sweden)
Kamon Chaiyasit
2015-06-01
Full Text Available Ebola haemorrhagic fever is a viral infection causing a major health problem worldwide. In this short article, the authors briefly review and discuss on the nutritional management (energy, protein, fat and micronutrient in management of Ebola infection.
Therapeutic management of Crimean-Congo haemorrhagic fever.
de la Calle-Prieto, Fernando; Martín-Quirós, Alejandro; Trigo, Elena; Mora-Rillo, Marta; Arsuaga, Marta; Díaz-Menéndez, Marta; Arribas, José Ramón
2017-06-29
Crimean-Congo haemorrhagic fever has been reported in more than 30 countries in Africa, Asia, the Middle East and Eastern Europe, with an increasing incidence in recent years, especially in Europe. Because no specific treatments have demonstrated efficacy, supportive treatment is essential, as well as the provision of a centre with the appropriate means to guarantee the safety of its healthcare professionals. Laboratory monitoring of thrombocytopenia, severe coagulopathy or liver failure is of critical importance. Patients with Crimean-Congo haemorrhagic fever should be admitted to High Level Isolation Units where appropriate biocontainment procedures can prevent nosocomial transmission through infected fluids or accidents with contaminated material. In case of high-risk exposures, early administration of ribavirin should be considered. Copyright © 2017. Publicado por Elsevier España, S.L.U.
Pittalis, Silvia; Fusco, Francesco Maria; Lanini, Simone; Nisii, Carla; Puro, Vincenzo; Lauria, Francesco Nicola; Ippolito, Giuseppe
2009-10-01
Viral haemorrhagic fevers (VHFs) represent a challenge for public health because of their epidemic potential, and their possible use as bioterrorism agents poses particular concern. In 1999 the World Health Organization (WHO) proposed a case definition for VHFs, subsequently adopted by other international institutions with the aim of early detection of initial cases/outbreaks in western countries. We applied this case definition to reports of Ebola and Marburg virus infections to estimate its sensitivity to detect cases of the disease. We analyzed clinical descriptions of 795 reported cases of Ebola haemorrhagic fever: only 58.5% of patients met the proposed case definition. A similar figure was obtained reviewing 169 cases of Marburg diseases, of which only 64.5% were in accordance with the case definition. In conclusion, the WHO case definition for hemorrhagic fevers is too specific and has poor sensitivity both for case finding during Ebola or Marburg outbreaks, and for early detection of suspected cases in western countries. It can lead to a hazardous number of false negatives and its use should be discouraged for early detection of cases.
Filoviral haemorrhagic fevers: A threat to Zambia?
Directory of Open Access Journals (Sweden)
Katendi Changula
2012-06-01
Full Text Available Filoviral haemorrhagic fevers (FVHF are caused by agents belonging to Filoviridae family, Ebola and Marburg viruses. They are amongst the most lethal pathogens known to infect humans. Incidence of FVHF outbreaks are increasing, with affected number of patients on the rise. Whilst there has been no report yet of FVHF in Zambia, its proximity to Angola and Democratic Republic of Congo, which have recorded major outbreaks, as well as the open borders, increased trade and annual migration of bats between these countries, puts Zambia at present and increased risk. Previous studies have indicated bats as potential reservoir hosts for filoviruses. An increasing population with an increasing demand for resources has forced incursion into previously uninhabited land, potentially bringing them into contact with unknown pathogens, reservoir hosts and/or amplifying hosts. The recent discovery of a novel arenavirus, Lujo, highlights the potential that every region, including Zambia, has for being the epicentre or primary focus for emerging and re-emerging infections. It is therefore imperative that surveillance for potential emerging infections, such as viral haemorrhagic fevers be instituted. In order to accomplish this surveillance, rapid detection, identification and monitoring of agents in patients and potential reservoirs is needed. International co-operation is the strategy of choice for the surveillance and fight against emerging infections. Due to the extensive area in which filoviral infections can occur, a regional approach to surveillance activities is required, with regional referral centres. There is a need to adopt shared policies for the prevention and control of infectious diseases. There is also need for optimisation of currently available tests and development of new diagnostic tests, in order to have robust, highly sensitive and specific diagnostic tests that can be used even where there are inadequate laboratories and diagnostic services.
First dengue haemorrhagic fever epidemic in the Americas, 1981: insights into the causative agent.
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.
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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.
Dengue Haemorrhagic Fever presenting as Acute Abdomen
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...
Retroperitoneal Haematoma in a Patient with Dengue Haemorrhagic Fever: A Rare Case Report.
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.
Lani, R; Mohd Rahim, N F; Hassan, H; Yaghoobi, R; Chang, L-Y; AbuBakar, S; Zandi, K
2015-01-01
The Crimean-Congo haemorrhagic fever virus (CCHFV), which is transmitted by the ticks of Hyalomma spp. in general and H. marginatumin particular, can cause severe disease in humans, with mortality rates of 3-30%. Other than from the bites of infected ticks, CCHFV can also be transmitted through contact with patients with the acute phase of infection or contact with blood or tissues from viraemic livestock. Outbreaks of human cases of haemorrhagic manifestations have been documented since 1945 and described in parts of Africa, Asia, Eastern Europe and the Middle East and most recently India in 2011. In addition, serological evidence of the disease has been reported in some countries where no human cases were reported. As regional neighbours China and India have been affected by this virus, this study was conducted to determine the seroprevalence of CCHFV among Orang Asli population of Malaysia as the most at risk people who residing in the deep forests. A total of 682 serum samples were collected from the Orang Asli population residing in eight states in peninsular Malaysia and analysed for the presence of anti-CCHFV immunoglobulin G (IgG) using a commercial enzyme-linked immunosorbent assay kit. The study subjects comprised 277 (40.6%) men and 405 (59.4%) women. However, anti-CCHFV IgG was detected in only one female serum sample (0.1%). The presence of anti-CCHFV IgG could not be correlated to age or sex from these findings. The results of this screening survey showed that the seroprevalence of the anti-CCHFV IgG among Malaysia's Orang Asli population is too low for detection or totally negative compared with that in neighbouring countries, such as India and China.
Seroepidemiological study of Crimean-Congo haemorrhagic fever in Greece, 2009-2010.
Sidira, P; Maltezou, H C; Haidich, A-B; Papa, A
2012-02-01
To estimate endemic areas for Crimean-Congo haemorrhagic fever (CCHF) in Greece, a country-wide seroepidemiological study was conducted, and 1611 human sera were prospectively collected along with data regarding possible risk factors for acquisition of infection, and tested for CCHF virus IgG antibodies by ELISA. The overall seroprevalence was 4.2%, with significant differences among prefectures, ranging from 0 to 27.5%. Multivariate analysis revealed that slaughtering and agricultural activities were significant risk factors for CCHFV seropositivity. The significantly high seroprevalence in specific prefectures, together with the extremely low number of CCHF cases, suggest that this phenomenon might be strain-related. © 2011 The Authors. Clinical Microbiology and Infection © 2011 European Society of Clinical Microbiology and Infectious Diseases.
Crimean-Congo Haemorrhagic Fever in Kosova : a fatal case report
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Raka Lul
2006-10-01
Full Text Available Abstract Crimean-Congo haemorrhagic fever (CCHF is an often fatal viral infection described in about 30 countries around the world. The authors report a fatal case of Crimean-Congo hemorrhagic fever (CCHF observed in a patient from Kosova. The diagnosis of CCHF was confirmed by reverse transcription-PCR. Late diagnosis decreased the efficacy of treatment and patient died due to severe complications of infection.
Beasley, David W C; McAuley, Alexander J; Bente, Dennis A
2015-03-01
Yellow fever virus (YFV) is the prototypical hemorrhagic fever virus, yet our understanding of its phenotypic diversity and any molecular basis for observed differences in disease severity and epidemiology is lacking, when compared to other arthropod-borne and haemorrhagic fever viruses. This is, in part, due to the availability of safe and effective vaccines resulting in basic YFV research taking a back seat to those viruses for which no effective vaccine occurs. However, regular outbreaks occur in endemic areas, and the spread of the virus to new, previously unaffected, areas is possible. Analysis of isolates from endemic areas reveals a strong geographic association for major genotypes, and recent epidemics have demonstrated the emergence of novel sequence variants. This review aims to outline the current understanding of YFV genetic and phenotypic diversity and its sources, as well as the available animal models for characterizing these differences in vivo. The consequences of genetic diversity for detection and diagnosis of yellow fever and development of new vaccines and therapeutics are discussed. Copyright © 2015 Elsevier B.V. All rights reserved.
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
Risk of transmission of viral haemorrhagic fevers and the insecticide ...
African Journals Online (AJOL)
... of transmission of viral haemorrhagic fevers and the insecticide susceptibility status of Ae. aegypti in some sites in Accra, Ghana. Design: Larval surveys were carried to inspect containers within households and estimate larval indices and adult Aedes mosquitoes were collected using human landing collection technique.
Marburg haemorrhagic fever: recent advances | AdegborO | African ...
African Journals Online (AJOL)
With the exception of a vaccine for yellow fever and ribavirin, which is used for treatment of some arenaviral infections, no specific chemotherapy for viral hemorrhagic fever exists. Only supportive treatment is possible The filoviruses, Marburg virus (MARV) and Ebola virus (EBOV), have been associated with hemorrhagic ...
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.
Surveillance and laboratory detection system of Crimean-Congo haemorrhagic fever in Iran
DEFF Research Database (Denmark)
Chinikar, S; Goya, M M; Shirzadi, M R
2008-01-01
Crimean-Congo haemorrhagic fever (CCHF) is a viral zoonotic disease with a high mortality rate in humans. The CCHF virus (CCHFV) is transmitted to humans through the bite of Ixodid ticks or by contact with blood or tissues of infected livestock. In addition to zoonotic transmission, CCHFV can be ....... After two decades and observations of CCHF in some provinces of Iran, a CCHF surveillance and detection system was established in 1999, leading to a dramatically decreased mortality rate from 20% (year 2000) to 2% (year 2007)....... symptoms, the diagnosis of CCHF is based on the use of serological tests for the detection of immunoglobulin M and immunoglobulin G antibodies and on the use of molecular tools such as RT-PCR. From 1970 to 1978, serological and epidemiological studies were performed in humans and in livestock of Iran...
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Thameur B. Hassine
2017-03-01
Full Text Available A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV, bluetongue virus (BTV, epizootic haemorrhagic disease virus (EHDV and Rift Valley fever virus (RVFV. In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.
Hassine, Thameur B; Amdouni, Jihane; Monaco, Federica; Savini, Giovanni; Sghaier, Soufien; Selimen, Imed B; Chandoul, Walid; Hamida, Khaled B; Hammami, Salah
2017-03-31
A total of 118 sera were collected during 2016 from two groups of dromedaries from Kebili and Medenine governorates in the south of Tunisia. The aim of this study was to provide the first serological investigation of four emerging vector-borne diseases in two groups of dromedaries in Tunisia. Sera were tested by ELISA and serum neutralisation test to identify West Nile virus (WNV), bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and Rift Valley fever virus (RVFV). In the first group, the seroprevalence for BTV was 4.6%, while in the second group, it was 25.8% for WNV and 9.7% for BTV. Only serotype 1 was detected for BTV in the two groups. No evidence for circulation of RVF and EHD viruses was revealed. Results indicated that dromedaries can be infected with BTV and WNV, suggesting that this species might play a significant role in the epizootiology of these viral diseases in Tunisia and neighbouring countries.
Ebola haemorrhagic fever virus: pathogenesis, immune responses, potential prevention.
Marcinkiewicz, Janusz; Bryniarski, Krzysztof; Nazimek, Katarzyna
2014-01-01
Ebola zoonotic RNA filovirus represents human most virulent and lethal pathogens, which induces acute hemorrhagic fever and death within few days in a range of 60-90% of symptomatic individuals. Last outbreak in 2014 in West Africa caused panic that Ebola epidemic can be spread to other continents. Number of deaths in late December reached almost 8,000 individuals out of more than 20,000 symptomatic patients. It seems that only a coordinated international response could counteract the further spread of Ebola. Major innate immunity mechanisms against Ebola are associated with the production of interferons, that are inhibited by viral proteins. Activation of host NK cells was recognized as a leading immune function responsible for recovery of infected people. Uncontrolled cell infection by Ebola leads to an impairment of immunity with cytokine storm, coagulopathy, systemic bleeding, multi-organ failure and death. Tested prevention strategies to induce antiviral immunity include: i. recombinant virus formulations (vaccines); ii. cocktail of monoclonal antibodies (serotherapy); iii. alternative RNA-interference-based antiviral methods. Maintaining the highest standards of aseptic and antiseptic precautions is equally important. Present brief review summarizes a current knowledge concerning pathogenesis of Ebola hemorrhagic disease and the virus interaction with the immune system and discusses recent advances in prevention of Ebola infection by vaccination and serotherapy.
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S Sulaiman
2007-12-01
Full Text Available In Southeast Asia, Aedes aegypti (L. has been incriminated as principal vector of dengue viruses and Ae. albopictus as the secondary vector of dengue fever. Therefore, the aim of this study was to investigate the effectiveness of three for-mula¬tions of pyrethrin derived from Tanacetum cinerariaefolium against the dengue/dengue haemorrhagic fever vectors Aedes aegypti and Ae. albopictus in the laboratory. The testings employed 2 methodologies: the WHO Larval Bioassay and WHO Adult Bioassay. The results showed that all the three pyrethrin formulations had larvicidal and adulticidal activi-ties. The impact of the sublethal doses of pyrethrin formulations on Aedes spp. larvae resulted in 4-6% of alive adult emergence compared to 90% of Ae. aegypti emerging adults and 96% Ae. albopictus alive adult emergence in the control. The impact of sublethal doses of the pyrethrin formulations caused very low fecundity on both Aedes spp. compared to the control (P< 0.05.
Directory of Open Access Journals (Sweden)
S Sulaiman
2007-11-01
Full Text Available In Southeast Asia, Aedes aegypti (L. has been incriminated as principal vector of dengue viruses and Ae. albopictus as the secondary vector of dengue fever. Therefore, the aim of this study was to investigate the effectiveness of three for-mula¬tions of pyrethrin derived from Tanacetum cinerariaefolium against the dengue/dengue haemorrhagic fever vectors Aedes aegypti and Ae. albopictus in the laboratory. The testings employed 2 methodologies: the WHO Larval Bioassay and WHO Adult Bioassay. The results showed that all the three pyrethrin formulations had larvicidal and adulticidal activi-ties. The impact of the sublethal doses of pyrethrin formulations on Aedes spp. larvae resulted in 4-6% of alive adult emergence compared to 90% of Ae. aegypti emerging adults and 96% Ae. albopictus alive adult emergence in the control. The impact of sublethal doses of the pyrethrin formulations caused very low fecundity on both Aedes spp. compared to the control (P< 0.05.
Directory of Open Access Journals (Sweden)
Alana Hansen
2015-04-01
Full Text Available Haemorrhagic fever with renal syndrome (HFRS is a rodent-borne disease that poses a serious public health threat in China. HFRS is caused by hantaviruses, mainly Seoul virus in urban areas and Hantaan virus in agricultural areas. Although preventive measures including vaccination programs and rodent control measures have resulted in a decline in cases in recent years, there has been an increase in incidence in some areas and new endemic areas have emerged. This review summarises the recent literature relating to the effects of climatic factors on the incidence of HFRS in China and discusses future research directions. Temperature, precipitation and humidity affect crop yields, rodent breeding patterns and disease transmission, and these can be influenced by a changing climate. Detailed surveillance of infections caused by Hantaan and Seoul viruses and further research on the viral agents will aid in interpretation of spatiotemporal patterns and a better understanding of the environmental and ecological drivers of HFRS amid China's rapidly urbanising landscape and changing climate.
Roles of African swine fever virus structural proteins in viral infection
Directory of Open Access Journals (Sweden)
Jia Ning
2017-06-01
Full Text Available African swine fever virus (ASFV is a large, double-stranded DNA virus and the sole member of the Asfarviridae family. ASFV infects domestic pigs, wild boars, warthogs, and bush pigs, as well as soft ticks (Ornithodoros erraticus, which likely act as a vector. The major target is swine monocyte-macrophage cells. The virus can cause high fever, haemorrhagic lesions, cyanosis, anorexia, and even fatalities in domestic pigs. Currently, there is no vaccine and effective disease control strategies against its spread are culling infected pigs and maintaining high biosecurity standards. African swine fever (ASF spread to Europe from Africa in the middle of the 20th century, and later also to South America and the Caribbean. Since then, ASF has spread more widely and thus is still a great challenge for swine breeding. The genome of ASFV ranges in length from about 170 to 193 kbp depending on the isolate and contains between 150 and 167 open reading frames (ORFs. The ASFV genome encodes 150 to 200 proteins, around 50 of them structural. The roles of virus structural proteins in viral infection have been described. These proteins, such as pp220, pp62, p72, p54, p30, and CD2v, serve as the major component of virus particles and have roles in attachment, entry, and replication. All studies on ASFV proteins lay a good foundation upon which to clarify the infection mechanism and develop vaccines and diagnosis methods. In this paper, the roles of ASFV structural proteins in viral infection are reviewed.
Nakounné, E; Selekon, B; Morvan, J
2000-01-01
An investigation was conducted between 1994 and 1997 in forested areas of the Central African Republic (CAR) to determine the seroprevalence of IgG antibodies against several haemorrhagic fever viruses present in the region. Sera were obtained from 1762 individuals in two groups (Pygmy and Bantu locuted populations) living in 4 forested areas in the south of the country. Sera were tested for IgG antibodies against Ebola, Marburg, Rift Valley fever (RVF), Yellow fever (YF) and Hantaviruses by enzyme immunoassay (EIA), and against Lassa virus by immunofluorescent assay. The prevalence of IgG antibodies was 5.9% for Ebola, 2% for Marburg, 6.9% pour RVF, 6.5% for YF, 2% for Hantaan. No antibodies were detected against Lassa, Seoul, Puumala and Thottapalayam viruses. No IgM antibodies were detected against RVF and YF viruses. The distribution of antibodies appears to be related to tropical rain forest areas. This study indicates that several haemorrhagic fever viruses are endemic in forested areas of the CAR and could emerge due to environmental modification.
Rift Valley fever virus MP-12 vaccine encoding Toscana virus NSs retains neuroinvasiveness in mice.
Indran, Sabarish V; Lihoradova, Olga A; Phoenix, Inaia; Lokugamage, Nandadeva; Kalveram, Birte; Head, Jennifer A; Tigabu, Bersabeh; Smith, Jennifer K; Zhang, Lihong; Juelich, Terry L; Gong, Bin; Freiberg, Alexander N; Ikegami, Tetsuro
2013-07-01
Rift Valley fever is a mosquito-borne zoonotic disease endemic to sub-Saharan Africa. Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) causes high rates of abortion and fetal malformation in pregnant ruminants, and haemorrhagic fever, neurological disorders or blindness in humans. The MP-12 strain is a highly efficacious and safe live-attenuated vaccine candidate for both humans and ruminants. However, MP-12 lacks a marker to differentiate infected from vaccinated animals. In this study, we originally aimed to characterize the efficacy of a recombinant RVFV MP-12 strain encoding Toscana virus (TOSV) NSs gene in place of MP-12 NSs (rMP12-TOSNSs). TOSV NSs promotes the degradation of dsRNA-dependent protein kinase (PKR) and inhibits interferon-β gene up-regulation without suppressing host general transcription. Unexpectedly, rMP12-TOSNSs increased death in vaccinated outbred mice and inbred BALB/c or C57BL/6 mice. Immunohistochemistry showed diffusely positive viral antigens in the thalamus, hypothalamus and brainstem, including the medulla. No viral antigens were detected in spleen or liver, which is similar to the antigen distribution of moribund mice infected with MP-12. These results suggest that rMP12-TOSNSs retains neuroinvasiveness in mice. Our findings demonstrate that rMP12-TOSNSs causes neuroinvasion without any hepatic disease and will be useful for studying the neuroinvasion mechanism of RVFV and TOSV.
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)
Biosafety standards for working with Crimean-Congo hemorrhagic fever virus.
Weidmann, Manfred; Avsic-Zupanc, Tatjana; Bino, Silvia; Bouloy, Michelle; Burt, Felicity; Chinikar, Sadegh; Christova, Iva; Dedushaj, Isuf; El-Sanousi, Ahmed; Elaldi, Nazif; Hewson, Roger; Hufert, Frank T; Humolli, Isme; Jansen van Vuren, Petrus; Koçak Tufan, Zeliha; Korukluoglu, Gülay; Lyssen, Pieter; Mirazimi, Ali; Neyts, Johan; Niedrig, Matthias; Ozkul, Aykut; Papa, Anna; Paweska, Janusz; Sall, Amadou A; Schmaljohn, Connie S; Swanepoel, Robert; Uyar, Yavuz; Weber, Friedemann; Zeller, Herve
2016-11-01
In countries from which Crimean-Congo haemorrhagic fever (CCHF) is absent, the causative virus, CCHF virus (CCHFV), is classified as a hazard group 4 agent and handled in containment level (CL)-4. In contrast, most endemic countries out of necessity have had to perform diagnostic tests under biosafety level (BSL)-2 or -3 conditions. In particular, Turkey and several of the Balkan countries have safely processed more than 100 000 samples over many years in BSL-2 laboratories. It is therefore advocated that biosafety requirements for CCHF diagnostic procedures should be revised, to allow the tests required to be performed under enhanced BSL-2 conditions with appropriate biosafety laboratory equipment and personal protective equipment used according to standardized protocols in the countries affected. Downgrading of CCHFV research work from CL-4, BSL-4 to CL-3, BSL-3 should also be considered.
England, Marion E; Phipps, Paul; Medlock, Jolyon M; Atkinson, Peter M; Atkinson, Barry; Hewson, Roger; Gale, Paul
2016-06-01
Crimean-Congo haemorrhagic fever virus (CCHFV) is a zoonotic virus transmitted by Hyalomma ticks, the immature stages of which may be carried by migratory birds. In this study, a total of 12 Hyalomma ticks were recovered from five of 228 migratory birds trapped in Spring, 2012 in southern Spain along the East Atlantic flyway. All collected ticks tested negative for CCHFV. While most birds had zero Hyalomma ticks, two individuals had four and five ticks each and the statistical distribution of Hyalomma tick counts per bird is over-dispersed compared to the Poisson distribution, demonstrating the need for intensive sampling studies to avoid underestimating the total number of ticks. Rates of tick exchange on migratory birds during their northwards migration will affect the probability that a Hyalomma tick entering Great Britain is positive for CCHFV. Drawing on published data, evidence is presented that the latitude of a European country affects the probability of entry of Hyalomma ticks on wild birds. Further data on Hyalomma infestation rates and tick exchange rates are required along the East Atlantic flyway to further our understanding of the origin of Hyalomma ticks (i.e., Africa or southern Europe) and hence the probability of entry of CCHFV into GB. © 2016 The Society for Vector Ecology.
Dengue fever and dengue haemorrhagic fever in adolescents and adults
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...
Dengue fever with hepatitis E and hepatitis A infection.
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.
DEFF Research Database (Denmark)
Schönherz, A. A.; Lorenzen, Niels; Einer-Jensen, Katja
2012-01-01
Viral haemorrhagic septicaemia is a serious viral disease of teleost fish with high economic impact on the aquaculture industry. The disease is caused by the viral haemorrhagic septicaemia virus (VHSV), an RNA virus belonging to the family Rhabdoviridae. Compared to other rhabdoviruses infecting...
Antigenic structure of the capsid protein of rabbit haemorrhagic disease virus
DEFF Research Database (Denmark)
Martinez-Torrecuadrada, Jorge L.; Cortes, Elena; Vela, Carmen
1998-01-01
Rabbit haemorrhagic disease virus (RHDV) causes an important disease in rabbits. The virus capsid is composed of a single 60 kDa protein. The capsid protein gene was cloned in Escherichia coli using the pET3 system, and the antigenic structure of RHDV VP60 was dissected using 11 monoclonal...
Ebolavirus and Haemorrhagic Syndrome
Directory of Open Access Journals (Sweden)
Gerald A. Matua
2015-05-01
Full Text Available The Ebola virus is a highly virulent, single-stranded ribonucleic acid virus which affects both humans and apes and has fast become one of the world’s most feared pathogens. The virus induces acute fever and death, with haemorrhagic syndrome occurring in up to 90% of patients. The known species within the genus Ebolavirus are Bundibugyo, Sudan, Zaïre, Reston and Taï Forest. Although endemic in Africa, Ebola has caused worldwide anxiety due to media hype and concerns about its international spread, including through bioterrorism. The high fatality rate is attributed to unavailability of a standard treatment regimen or vaccine. The disease is frightening since it is characterised by rapid immune suppression and systemic inflammatory response, causing multi-organ and system failure, shock and often death. Currently, disease management is largely supportive, with containment efforts geared towards mitigating the spread of the virus. This review describes the classification, morphology, infective process, natural ecology, transmission, epidemic patterns, diagnosis, clinical features and immunology of Ebola, including management and epidemic containment strategies.
Ebolavirus and Haemorrhagic Syndrome.
Matua, Gerald A; Van der Wal, Dirk M; Locsin, Rozzano C
2015-05-01
The Ebola virus is a highly virulent, single-stranded ribonucleic acid virus which affects both humans and apes and has fast become one of the world's most feared pathogens. The virus induces acute fever and death, with haemorrhagic syndrome occurring in up to 90% of patients. The known species within the genus Ebolavirus are Bundibugyo, Sudan, Zaïre, Reston and Taï Forest. Although endemic in Africa, Ebola has caused worldwide anxiety due to media hype and concerns about its international spread, including through bioterrorism. The high fatality rate is attributed to unavailability of a standard treatment regimen or vaccine. The disease is frightening since it is characterised by rapid immune suppression and systemic inflammatory response, causing multi-organ and system failure, shock and often death. Currently, disease management is largely supportive, with containment efforts geared towards mitigating the spread of the virus. This review describes the classification, morphology, infective process, natural ecology, transmission, epidemic patterns, diagnosis, clinical features and immunology of Ebola, including management and epidemic containment strategies.
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)
African Swine Fever Virus Biology and Vaccine Approaches.
Revilla, Yolanda; Pérez-Núñez, Daniel; Richt, Juergen A
2018-01-01
African swine fever (ASF) is an acute and often fatal disease affecting domestic pigs and wild boar, with severe economic consequences for affected countries. ASF is endemic in sub-Saharan Africa and the island of Sardinia, Italy. Since 2007, the virus emerged in the republic of Georgia, and since then spread throughout the Caucasus region and Russia. Outbreaks have also been reported in Belarus, Ukraine, Lithuania, Latvia, Estonia, Romania, Moldova, Czech Republic, and Poland, threatening neighboring West European countries. The causative agent, the African swine fever virus (ASFV), is a large, enveloped, double-stranded DNA virus that enters the cell by macropinocytosis and a clathrin-dependent mechanism. African Swine Fever Virus is able to interfere with various cellular signaling pathways resulting in immunomodulation, thus making the development of an efficacious vaccine very challenging. Inactivated preparations of African Swine Fever Virus do not confer protection, and the role of antibodies in protection remains unclear. The use of live-attenuated vaccines, although rendering suitable levels of protection, presents difficulties due to safety and side effects in the vaccinated animals. Several African Swine Fever Virus proteins have been reported to induce neutralizing antibodies in immunized pigs, and vaccination strategies based on DNA vaccines and recombinant proteins have also been explored, however, without being very successful. The complexity of the virus particle and the ability of the virus to modulate host immune responses are most likely the reason for this failure. Furthermore, no permanent cell lines able to sustain productive virus infection by both virulent and naturally attenuated African Swine Fever Virus strains exist so far, thus impairing basic research and the commercial production of attenuated vaccine candidates. © 2018 Elsevier Inc. All rights reserved.
Energy Technology Data Exchange (ETDEWEB)
Jaing, C; Gardner, S
2012-06-05
The goal of this project is to develop forensic genotyping assays for select agent viruses, enhancing the current capabilities for the viral bioforensics and law enforcement community. We used a multipronged approach combining bioinformatics analysis, PCR-enriched samples, microarrays and TaqMan assays to develop high resolution and cost effective genotyping methods for strain level forensic discrimination of viruses. We have leveraged substantial experience and efficiency gained through year 1 on software development, SNP discovery, TaqMan signature design and phylogenetic signature mapping to scale up the development of forensics signatures in year 2. In this report, we have summarized the whole genome wide SNP analysis and microarray probe design for forensics characterization of South American hemorrhagic fever viruses, tick-borne encephalitis viruses and henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus and Japanese encephalitis virus.
West Africa Ebola Virus Disease Epidemic: The Africa Experience ...
African Journals Online (AJOL)
Ebola Virus Disease (EVD), formerly known as Ebola haemorrhagic fever, is a severe acute viral illness characterized by sudden onset of fever, myalgia, malaise, and severe headache, followed by vomiting and diarrhea and, in some instances, bleeding. The 2014 West Africa outbreak is the largest in history, affecting ...
Dengue fever outbreak: a clinical management experience.
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
Neisseria meningitidis: a neglected cause of infectious haemorrhagic fever in the amazon rainforest.
Barroso, David E; Silva, Luciete A
2007-12-01
Neisseria meningitidis has not been seen as a significant cause of infectious haemorrhagic fever in the Amazon inlands; most reported cases are from the city of Manaus, the capital of the State of Amazonas. This picture is sustained by the lack of reliable microbiology laboratories, the perception of the health care workers, and the difficult to reach medical assistance; thus the number of confirmed cases is even lower with no reference of the strains phenotype. We report here the investigation of a case of suspected meningococcemia and his close contacts in a rural community in the Coari Lake, up the Amazon River.
Kortekaas, J.A.; Ergonul, O.; Moormann, R.J.M.
2010-01-01
ARBO-ZOONET is an international network financed by the European Commission's seventh framework program. The major goal of this initiative is capacity building for the control of emerging viral vector-borne zoonotic diseases, with a clear focus on West Nile virus, Rift Valley fever virus, and
Expression of VP60 gene from rabbit haemorrhagic disease virus ...
African Journals Online (AJOL)
The VP60 gene from rabbit haemorrhagic disease virus (RHDV) YL strain in Northeast of China, under control of the ats1A promoter from Rubisco small subunit genes of Arabidopsis thaliana, was introduced into the transfer deoxyribonucleic acid (T-DNA) region of plant transfer vector pCAMBIA1300 and transferred to ...
STUDIES ON THE PATHOGENESIS OF FEVER WITH INFLUENZAL VIRUSES
Atkins, Elisha; Huang, Wei Cheng
1958-01-01
A substance with pyrogenic properties appears in the blood streams of rabbits made febrile by the intravenous inoculation of the PR8 strain of influenza A and Newcastle disease viruses (NDV). By means of a technique involving passive transfer of sera from animals given virus to recipient rabbits, the titer of circulating pyrogen was found to be closely correlated with the course of fever produced by virus. Certain properties of the pyrogen are described which differentiate it from the originally injected virus and suggest that the induced pyrogen is of endogenous origin. These properties resemble those of endogenous pyrogens occurring in other forms of experimental fever. The source of virus-induced pyrogen is unknown. In vitro incubation of virus with various constituents of the circulation did not result in the appearance of endogenous pyrogen. Granulocytopenia induced by HN2 failed to influence either fever or the production of endogenous pyrogen in rabbits injected with NDV. Similarly, the intraperitoneal inoculation of NDV into prepared exudates did not modify the febrile response. These findings do not lend support to the possibility that the polymorphonuclear leukocyte is a significant source of endogenous pyrogen in virus-induced fever. It is concluded that the liberation of an endogenous pyrogen from some as yet undefined source is an essential step in the pathogenesis of fever caused by the influenza group of viruses. PMID:13513908
Electron microscopic identification of Zinga virus as a strain of Rift Valley fever virus.
Olaleye, O D; Baigent, C L; Mueller, G; Tomori, O; Schmitz, H
1992-01-01
Electron microscopic examination of a negatively stained suspension of Zinga virus showed particles 90-100 nm in diameter, enveloped with spikes 12-20 nm in length and 5 nm in diameter. Further identification of the virus by immune electron microscopy showed the reactivity of human Rift Valley fever virus-positive serum with Zinga virus. Results of this study are in agreement with earlier reports that Zinga virus is a strain of Rift Valley fever virus.
Genetic population structure of marine viral haemorrhagic septicaemia virus (VHSV)
DEFF Research Database (Denmark)
Snow, M.; Bain, N.; Black, J.
2004-01-01
The nucleotide sequences of a specific region of the nucleoprotein gene were compared in order to investigate the genetic population structure of marine viral haemorrhagic septicaemia virus (VHSV). Analysis of the sequence from 128 isolates of diverse geographic and host origin renders this the m......The nucleotide sequences of a specific region of the nucleoprotein gene were compared in order to investigate the genetic population structure of marine viral haemorrhagic septicaemia virus (VHSV). Analysis of the sequence from 128 isolates of diverse geographic and host origin renders...... this the most comprehensive molecular epidemiological study of marine VHSV conducted to date. Phylogenetic analysis of nucleoprotein gene sequences confirmed the existence of the 4 major genotypes previously identified based on N- and subsequent G-gene based analyses. The range of Genotype I included subgroups...... of isolates associated with rainbow trout aquaculture (Genotype la) and those from the Baltic marine environment (Genotype Ib) to emphasise the relatively close genetic relationship between these isolates. The existence of an additional genotype circulating within the Baltic Sea (Genotype II) was also...
Directory of Open Access Journals (Sweden)
Ľubomír Pojezdal
2017-01-01
Full Text Available The diagnostic properties of the one-step real-time reverse-transcription polymerase chain reaction assay for viral haemorrhagic septicaemia virus detection were compared to methods currently in use in the Czech Republic, namely, virus isolation using the cell culture and conventional reverse-transcription polymerase chain reaction followed by the nested polymerase chain reaction. The assays were tested on a panel of 25 archived viral haemorrhagic septicaemia isolates and 8 archived infectious haematopoietic necrosis isolates obtained from monitoring and/or outbreaks of the diseases among farmed salmonids in the Czech Republic. The ability to detect the presence of the virus in the tissues of fish was tested on additional 32 field samples collected from the rainbow trout (Oncorhynchus mykiss, brown trout (Salmo trutta and brook trout (Salvelinus fontinalis. The real-time assay showed the highest analytic sensitivity by detecting the presence of viral nucleic acid in samples with 10-7 dilution, whereas the sensitivity of the conventional polymerase chain reaction peaked at 10-5. Diagnostic specificity of both molecular assays was confirmed by absence of cross-reactivity with the infectious haematopoietic necrosis virus isolates. This, along with consistent results in the detection of the virus in the fish tissues, confirms that the one-step real-time reverse-transcription polymerase chain reaction is currently an optimal stand-alone diagnostic method for the detection of the viral haemorrhagic septicaemia virus.
Gilsdorf, Andreas; Morgan, Dilys; Leitmeyer, Katrin
2012-11-21
Travel from countries where viral haemorrhagic fevers (VHF) are endemic has increased significantly over the past decades. In several reported VHF events on airplanes, passenger trace back was initiated but the scale of the trace back differed considerably. The absence of guidance documents to help the decision on necessity and scale of the trace back contributed to this variation.This article outlines the recommendations of an expert panel on Lassa fever, Ebola and Marburg haemorrhagic fever to the wider scientific community in order to advise the relevant stakeholders in the decision and scale of a possible passenger trace back. The evidence was collected through review of published literature and through the views of an expert panel. The guidance was agreed by consensus. Only a few events of VHF cases during air travel are reported in literature, with no documented infection in followed up contacts, so that no evidence of transmission of VHF during air travel exists to date. Based on this and the expert opinion, it was recommended that passenger trace back was undertaken only if: the index case had symptoms during the flight; the flight was within 21 days after detection of the event; and for Lassa fever if exposure of body fluid has been reported. The trace back should only be done after confirmation of the index case. Passengers and crew with direct contact, seat neighbours (+/- 1 seat), crew and cleaning personal of the section of the index case should be included in the trace back. No evidence has been found for the transmission of VHF in airplanes. This information should be taken into account, when a trace back decision has to be taken, because such a measure produces an enormous work load. The procedure suggested by the expert group can guide decisions made in future events, where a patient with suspected VHF infection travelled on a plane. However, the actual decision on start and scale of a trace back always lies in the hands of the responsible people
Neisseria meningitidis: a neglected cause of infectious haemorrhagic fever in the amazon rainforest
Directory of Open Access Journals (Sweden)
David E. Barroso
Full Text Available Neisseria meningitidis has not been seen as a significant cause of infectious haemorrhagic fever in the Amazon inlands; most reported cases are from the city of Manaus, the capital of the State of Amazonas. This picture is sustained by the lack of reliable microbiology laboratories, the perception of the health care workers, and the difficult to reach medical assistance; thus the number of confirmed cases is even lower with no reference of the strains phenotype. We report here the investigation of a case of suspected meningococcemia and his close contacts in a rural community in the Coari Lake, up the Amazon River.
Tissue and cellular tropism, pathology and pathogenesis of Ebola and Marburg viruses.
Martines, Roosecelis Brasil; Ng, Dianna L; Greer, Patricia W; Rollin, Pierre E; Zaki, Sherif R
2015-01-01
Ebola viruses and Marburg viruses include some of the most virulent and fatal pathogens known to humans. These viruses cause severe haemorrhagic fevers, with case fatality rates in the range 25-90%. The diagnosis of filovirus using formalin-fixed tissues from fatal cases poses a significant challenge. The most characteristic histopathological findings are seen in the liver; however, the findings overlap with many other viral and non-viral haemorrhagic diseases. The need to distinguish filovirus infections from other haemorrhagic fevers, particularly in areas with multiple endemic viral haemorrhagic agents, is of paramount importance. In this review we discuss the current state of knowledge of filovirus infections and their pathogenesis, including histopathological findings, epidemiology, modes of transmission and filovirus entry and spread within host organisms. The pathogenesis of filovirus infections is complex and involves activation of the mononuclear phagocytic system, with release of pro-inflammatory cytokines, chemokines and growth factors, endothelial dysfunction, alterations of the innate and adaptive immune systems, direct organ and endothelial damage from unrestricted viral replication late in infection, and coagulopathy. Although our understanding of the pathogenesis of filovirus infections has rapidly increased in the past few years, many questions remain unanswered. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Monath, T P
2001-08-01
Yellow fever, the original viral haemorrhagic fever, was one of the most feared lethal diseases before the development of an effective vaccine. Today the disease still affects as many as 200,000 persons annually in tropical regions of Africa and South America, and poses a significant hazard to unvaccinated travellers to these areas. Yellow fever is transmitted in a cycle involving monkeys and mosquitoes, but human beings can also serve as the viraemic host for mosquito infection. Recent increases in the density and distribution of the urban mosquito vector, Aedes aegypti, as well as the rise in air travel increase the risk of introduction and spread of yellow fever to North and Central America, the Caribbean and Asia. Here I review the clinical features of the disease, its pathogenesis and pathophysiology. The disease mechanisms are poorly understood and have not been the subject of modern clinical research. Since there is no specific treatment, and management of patients with the disease is extremely problematic, the emphasis is on preventative vaccination. As a zoonosis, yellow fever cannot be eradicated, but reduction of the human disease burden is achievable through routine childhood vaccination in endemic countries, with a low cost for the benefits obtained. The biological characteristics, safety, and efficacy of live attenuated, yellow fever 17D vaccine are reviewed. New applications of yellow fever 17D virus as a vector for foreign genes hold considerable promise as a means of developing new vaccines against other viruses, and possibly against cancers.
Ebola Virus Disease – An Update
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Surekha Kishore
2014-12-01
Full Text Available Ebola Virus Disease (EVD is a severe, haemorrhagic febrile disease, often fatal in humans, caused by a non segmented, negative sense RNA virus of the family Filoviridae and genus Ebolavirus. It is also known as Ebola Haemorrhagic fever. There are five species of Ebolavirus, namely Bundibugyo ebolavirus, Zaire ebolavirus, Reston ebolavirus, Sudan ebolavirus and Tai Forest ebolavirus. The Zaire species has caused multiple large outbreaks with mortality rates of 55 to 88 percent since first appearance of the disease whereas the Sudan virus has been associated with an approximate 50 percent case-fatality rate in four known epidemics: two in Sudan in the 1970s, one in Uganda in 2000, and another in Sudan in 2004 [1-5].
Understanding the Dengue Viruses and Progress towards Their Control
Gould, Ernest A.
2013-01-01
Traditionally, the four dengue virus serotypes have been associated with fever, rash, and the more severe forms, haemorrhagic fever and shock syndrome. As our knowledge as well as understanding of these viruses increases, we now recognise not only that they are causing increasing numbers of human infections but also that they may cause neurological and other clinical complications, with sequelae or fatal consequences. In this review we attempt to highlight some of these features in the context of dengue virus pathogenesis. We also examine some of the efforts currently underway to control this “scourge” of the tropical and subtropical world. PMID:23936833
Lasecka, Lidia; Baron, Michael D
2014-01-01
Nairobi sheep disease virus (NSDV) of the genus Nairovirus causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%; the virus is found in East and Central Africa, and in India, where the virus is called Ganjam virus. NSDV is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus, which also causes a haemorrhagic disease. As with other nairoviruses, replication of NSDV takes place in the cytoplasm and the new virus particles bud into the Golgi apparatus; however, the effect of viral replication on cellular compartments has not been studied extensively. We have found that the overall structure of the endoplasmic reticulum (ER), the ER-Golgi intermediate compartment and the Golgi were unaffected by infection with NSDV. However, we observed that NSDV infection led to the loss of protein disulphide isomerase (PDI), an oxidoreductase present in the lumen of the endoplasmic reticulum (ER) and which assists during protein folding, from the ER. Further investigation showed that NSDV-infected cells have high levels of PDI at their surface, and PDI is also secreted into the culture medium of infected cells. Another chaperone from the PDI family, ERp57, was found to be similarly affected. Analysis of infected cells and expression of individual viral glycoproteins indicated that the NSDV PreGn glycoprotein is involved in redistribution of these soluble ER oxidoreductases. It has been suggested that extracellular PDI can activate integrins and tissue factor, which are involved respectively in pro-inflammatory responses and disseminated intravascular coagulation, both of which manifest in many viral haemorrhagic fevers. The discovery of enhanced PDI secretion from NSDV-infected cells may be an important finding for understanding the mechanisms underlying the pathogenicity of haemorrhagic nairoviruses.
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Lidia Lasecka
Full Text Available Nairobi sheep disease virus (NSDV of the genus Nairovirus causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%; the virus is found in East and Central Africa, and in India, where the virus is called Ganjam virus. NSDV is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus, which also causes a haemorrhagic disease. As with other nairoviruses, replication of NSDV takes place in the cytoplasm and the new virus particles bud into the Golgi apparatus; however, the effect of viral replication on cellular compartments has not been studied extensively. We have found that the overall structure of the endoplasmic reticulum (ER, the ER-Golgi intermediate compartment and the Golgi were unaffected by infection with NSDV. However, we observed that NSDV infection led to the loss of protein disulphide isomerase (PDI, an oxidoreductase present in the lumen of the endoplasmic reticulum (ER and which assists during protein folding, from the ER. Further investigation showed that NSDV-infected cells have high levels of PDI at their surface, and PDI is also secreted into the culture medium of infected cells. Another chaperone from the PDI family, ERp57, was found to be similarly affected. Analysis of infected cells and expression of individual viral glycoproteins indicated that the NSDV PreGn glycoprotein is involved in redistribution of these soluble ER oxidoreductases. It has been suggested that extracellular PDI can activate integrins and tissue factor, which are involved respectively in pro-inflammatory responses and disseminated intravascular coagulation, both of which manifest in many viral haemorrhagic fevers. The discovery of enhanced PDI secretion from NSDV-infected cells may be an important finding for understanding the mechanisms underlying the pathogenicity of haemorrhagic nairoviruses.
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Amr Murad
2008-09-01
Full Text Available A surveillance survey was conducted over a period of 12 months between September 2004 and August 2005 by the Tropical Medicine Department of Zagazig University in collaboration with Naval Medical Research Unit No. 3 (NAMRU-3, Egypt, to evaluate the role of ruminants as a reservoir host for Crimean-Congo haemorrhagic fever virus (CCHFV. A total of 1 022 serum samples from 313 cattle, 264 water buffalo (Bubalus bubalis, 270 sheep and 175 goats were included in the survey. All samples were collected from the Sharkia Governorate of Egypt and were examined for anti-CCHFV IgG. Of the total of 1 022 samples examined, 32 (3.13% were positive to IgG ELISA. Out of 270 sheep examined, 17 (6.30% were confirmed to have anti-CCHFV IgG with the highest titre recorded at 1:800. However, CCHFV-specific IgG-positive cases among the cattle, buffalo and goats were 3.83%, 0.38% and 1.14%, respectively. Positive cases in age group B (=2 years old were significantly higher (p<0.001 than those in age group A (<2 years old (5.7% versus 1.6%. Belbis City was found to have the highest number of positive cases compared to all other localities (p<0.001.
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Gilsdorf Andreas
2012-11-01
Full Text Available Abstract Background Travel from countries where viral haemorrhagic fevers (VHF are endemic has increased significantly over the past decades. In several reported VHF events on airplanes, passenger trace back was initiated but the scale of the trace back differed considerably. The absence of guidance documents to help the decision on necessity and scale of the trace back contributed to this variation. This article outlines the recommendations of an expert panel on Lassa fever, Ebola and Marburg haemorrhagic fever to the wider scientific community in order to advise the relevant stakeholders in the decision and scale of a possible passenger trace back. Method The evidence was collected through review of published literature and through the views of an expert panel. The guidance was agreed by consensus. Results Only a few events of VHF cases during air travel are reported in literature, with no documented infection in followed up contacts, so that no evidence of transmission of VHF during air travel exists to date. Based on this and the expert opinion, it was recommended that passenger trace back was undertaken only if: the index case had symptoms during the flight; the flight was within 21 days after detection of the event; and for Lassa fever if exposure of body fluid has been reported. The trace back should only be done after confirmation of the index case. Passengers and crew with direct contact, seat neighbours (+/− 1 seat, crew and cleaning personal of the section of the index case should be included in the trace back. Conclusion No evidence has been found for the transmission of VHF in airplanes. This information should be taken into account, when a trace back decision has to be taken, because such a measure produces an enormous work load. The procedure suggested by the expert group can guide decisions made in future events, where a patient with suspected VHF infection travelled on a plane. However, the actual decision on start and scale
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Xue-feng CAO
2017-08-01
Full Text Available Objective To establish a one-step recombinase polymerase amplification (RPA method for pathogen screening and rapid detection in the field targeting for five hemorrhagic fever related viruses (Zaire ebola virus, Sudan ebola virus, Marburg virus, Lassa virus and Yellow fever virus. Methods The specific nucleic acid (NA fragments of each virus were selected as target genes by genome sequence analysis, and the primers and probes for RPA assays were designed according to the sequence. A series of diluted template genes were used for RPA detection to determine the sensitivity. The hemorrhagic fever-related viral nucleic acids were used for RPA detection to determine the specificity. The amplification experiments were carried out at different temperature ranging from 37℃ to 42℃ to validate the reaction temperature range. Results The RPA reaction systems of the five hemorrhagic fever viruses could effectively amplify the target genes, the sensitivities were between 1.5×102 and 1.5×103 copies. No cross reactions existed with the other hemorrhagic fever-related viral genes. Meanwhile, RPA assay could effectively amplify the target genes at 37-42℃. Conclusion The isothermal RPA assays of five hemorrhagic fever viruses are established, which may amply target genes fast and react at a wide temperature range, and be potentially useful for in field pathogens detection. DOI: 10.11855/j.issn.0577-7402.2017.06.09
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Nagata Tatsuya
2011-05-01
Full Text Available Abstract Background Yellow fever is an haemorrhagic disease caused by a virus that belongs to the genus Flavivirus (Flaviviridae family and is transmitted by mosquitoes. Among the viral proteins, the envelope protein (E is the most studied one, due to its high antigenic potencial. Baculovirus are one of the most popular and efficient eukaryotic expression system. In this study a recombinant baculovirus (vSynYFE containing the envelope gene (env of the 17D vaccine strain of yellow fever virus was constructed and the recombinant protein antigenicity was tested. Results Insect cells infected with vSynYFE showed syncytium formation, which is a cytopathic effect characteristic of flavivirus infection and expressed a polypeptide of around 54 kDa, which corresponds to the expected size of the recombinant E protein. Furthermore, the recombinant E protein expression was also confirmed by fluorescence microscopy of vSynYFE-infected insect cells. Total vSynYFE-infected insect extracts used as antigens detected the presence of antibodies for yellow fever virus in human sera derived from yellow fever-infected patients in an immunoassay and did not cross react with sera from dengue virus-infected patients. Conclusions The E protein expressed by the recombinant baculovirus in insect cells is antigenically similar to the wild protein and it may be useful for different medical applications, from improved diagnosis of the disease to source of antigens for the development of a subunit vaccine.
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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.
Torres, J M; Ramírez, M A; Morales, M; Bárcena, J; Vázquez, B; Espuña, E; Pagès-Manté, A; Sánchez-Vizcaíno, J M
2000-09-15
We have recently developed a transmissible vaccine to immunize rabbits against myxomatosis and rabbit haemorrhagic disease based on a recombinant myxoma virus (MV) expressing the rabbit haemorrhagic disease virus (RHDV) capsid protein [Bárcena et al. Horizontal transmissible protection against myxomatosis and rabbit haemorragic disease using a recombinant myxoma virus. J. Virol. 2000;74:1114-23]. Administration of the recombinant virus protects rabbits against lethal RHDV and MV challenges. Furthermore, the recombinant virus is capable of horizontal spreading promoting protection of contact animals, thus providing the opportunity to immunize wild rabbit populations. However, potential risks must be extensively evaluated before considering its field use. In this study several safety issues concerning the proposed vaccine have been evaluated under laboratory conditions. Results indicated that vaccine administration is safe even at a 100-fold overdose. No undesirable effects were detected upon administration to immunosuppressed or pregnant rabbits. The recombinant virus maintained its attenuated phenotype after 10 passages in vivo.
Woodrow, Charles J; Eziefula, Alice C; Agranoff, Dan; Scott, Geoffrey M; Watson, Julie; Chiodini, Peter L; Lockwood, Diana N J; Grant, Alison D
2007-01-01
To implement a policy of systematic screening for viral haemorrhagic fever (VHF) among travellers returning from African countries with fever, commencing at initial clinical contact. A protocol based on UK Advisory Committee on Dangerous Pathogens guidance was developed collaboratively by medical, nursing and laboratory staff. Audit was carried out to quantify resource demands and effects on time to diagnose malaria, the main differential diagnosis. A protocol is now implemented for all patients presenting to HTD with fever, with clear guidelines for interaction with clinical and laboratory staff at each stage. The protocol required moderate amounts of clinical and laboratory staff time and resulted in some additional hospital admissions. The time to a diagnosis of malaria increased from a median of 90 (range 50-125) min in patients without VHF risk to a median of 140 (range 101-225) min (p=0.0025) in those assessed as at risk. Although all acute medical services need to have robust procedures for early detection of patients with serious transmissible conditions, few implement such a policy. Our protocol requires increased human and other resources but has no important impact on the rapidity of diagnosis of malaria, and is now embedded in local practice.
Companion Animals as a Source of Viruses for Human Beings and Food Production Animals.
Reperant, L A; Brown, I H; Haenen, O L; de Jong, M D; Osterhaus, A D M E; Papa, A; Rimstad, E; Valarcher, J-F; Kuiken, T
2016-07-01
Companion animals comprise a wide variety of species, including dogs, cats, horses, ferrets, guinea pigs, reptiles, birds and ornamental fish, as well as food production animal species, such as domestic pigs, kept as companion animals. Despite their prominent place in human society, little is known about the role of companion animals as sources of viruses for people and food production animals. Therefore, we reviewed the literature for accounts of infections of companion animals by zoonotic viruses and viruses of food production animals, and prioritized these viruses in terms of human health and economic importance. In total, 138 virus species reportedly capable of infecting companion animals were of concern for human and food production animal health: 59 of these viruses were infectious for human beings, 135 were infectious for food production mammals and birds, and 22 were infectious for food production fishes. Viruses of highest concern for human health included hantaviruses, Tahyna virus, rabies virus, West Nile virus, tick-borne encephalitis virus, Crimean-Congo haemorrhagic fever virus, Aichi virus, European bat lyssavirus, hepatitis E virus, cowpox virus, G5 rotavirus, influenza A virus and lymphocytic choriomeningitis virus. Viruses of highest concern for food production mammals and birds included bluetongue virus, African swine fever virus, foot-and-mouth disease virus, lumpy skin disease virus, Rift Valley fever virus, porcine circovirus, classical swine fever virus, equine herpesvirus 9, peste des petits ruminants virus and equine infectious anaemia virus. Viruses of highest concern for food production fishes included cyprinid herpesvirus 3 (koi herpesvirus), viral haemorrhagic septicaemia virus and infectious pancreatic necrosis virus. Of particular concern as sources of zoonotic or food production animal viruses were domestic carnivores, rodents and food production animals kept as companion animals. The current list of viruses provides an objective
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.
Transmission of yellow fever vaccine virus through breast-feeding - Brazil, 2009.
2010-02-12
In April, 2009, the state health department of Rio Grande do Sul, Brazil, was notified by the Cachoeira do Sul municipal health department of a case of meningoencephalitis requiring hospitalization in an infant whose mother recently had received yellow fever vaccine during a postpartum visit. The Field Epidemiology Training Program of the Secretariat of Surveillance in Health of the Brazilian Ministry of Health assisted state and municipal health departments with an investigation. This report summarizes the results of that investigation, which determined that the infant acquired yellow fever vaccine virus through breast-feeding. The mother reported 2 days of headache, malaise, and low fever occurring 5 days after receipt of yellow fever vaccine. The infant, who was exclusively breast-fed, was hospitalized at age 23 days with seizures requiring continuous infusion of intravenous anticonvulsants. The infant received antimicrobial and antiviral treatment for meningoencephalitis. The presence of 17DD yellow fever virus was detected by reverse transcription--polymerase chain reaction (RT-PCR) in the infant's cerebrospinal fluid (CSF); yellow fever--specific immunoglobulin M (IgM) antibodies also were present in serum and CSF. The infant recovered completely, was discharged after 24 days of hospitalization, and has had normal neurodevelopment and growth through age 6 months. The findings in this report provide documentation that yellow fever vaccine virus can be transmitted via breast-feeding. Administration of yellow fever vaccine to breast-feeding women should be avoided except in situations where exposure to yellow fever viruses cannot be avoided or postponed.
Dengue Fever/Dengue Haemorrhagic Fever : Case Management
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, ...
Arthropod-borne viral infections associated with a fever outbreak in the northern province of Sudan.
Watts, D M; el-Tigani, A; Botros, B A; Salib, A W; Olson, J G; McCarthy, M; Ksiazek, T G
1994-08-01
An outbreak of acute febrile illness occurred during August and September 1989 in the Northern Province of Sudan coinciding with a high population density of phlebotomine sandflies. An investigation was conducted to determine whether arboviruses were associated with human illness during this outbreak. Sera were obtained from 185 febrile individuals and tested for IgG and IgM antibody to selected arboviruses by enzyme immunoassay (EIA). The prevalence of IgG antibody was 59% for West Nile (WN), 53% for Sandfly Fever Sicilian (SFS), 32% for Sandfly Fever Naples (SFN), 39% for Yellow Fever (YF), 24% for dengue-2 (DEN-2), 23% for Rift Valley Fever (RVF), 12% for Chikungunya (CHIK) and 5% for Crimean-Congo haemorrhagic Fever (CCHF) viruses. Antibody prevalences tended to increase with age for WN and YF viruses. Antibody rates were about the same for males and females for most of the viruses tested. The prevalence of IgM antibody to SFN was 24% and reciprocal IgM titre exceeded 12,800 for some individuals suggesting that this virus was the cause of recent infection. The prevalence of IgM antibody for the other viruses did not exceed 5%. The study indicated that several arboviruses were endemic and some of them may have caused human disease in the Northern Province of Sudan.
Differentiation of strains of yellow fever virus in γ-irradiated mice
International Nuclear Information System (INIS)
Fitzgeorge, R.; Bradish, C.J.
1980-01-01
The mouse sensitized by optimal, sub-lethal γ-irradiation has been used for the differentiation of strains of yellow fever virus and for the resolution of their immunogenicity and pathogenicity as distinct characteristics. For different strains of yellow fever virus, the patterns of antibody-synthesis, regulatory immunity (pre-challenge) and protective immunity (post-challenge) are differentially sensitive to γ-irradiation. These critical differentiations of strains of yellow fever virus in γ-irradiated mice have been compared with those shown in normal athymic and immature mice in order to elucidate the range of quantifiable in vivo characteristics and the course of the virus-host interaction. This is discussed as a basis for the comparisons of the responses of model and principal hosts to vaccines and pathogens. (author)
No evidence of African swine fever virus replication in hard ticks
Carvalho Ferreira, de H.C.; Zúquete, S.T.; Wijnveld, M.; Weesendorp, E.; Jongejan, F.; Stegeman, J.A.; Loeffen, W.L.A.
2014-01-01
African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in
No evidence of African swine fever virus replication in hard ticks
de Carvalho Ferreira, Helena C; Tudela Zúquete, Sara; Wijnveld, Michiel; Weesendorp, Eefke; Jongejan, Frans; Stegeman, Arjan; Loeffen, Willie L A
African swine fever (ASF) is caused by African swine fever virus (ASFV), a tick-borne DNA virus. Soft ticks of the genus Ornithodoros are the only biological vectors of ASFV recognized so far. Although other hard ticks have been tested for vector competence, two commonly found tick species in
Comparison of sampling techniques for Rift Valley Fever virus ...
African Journals Online (AJOL)
time for trapping potential vectors for Rift Valley Fever virus. ..... Krockel, U., Rose, A., Eiras, A.E. & Geier, M. (2006) New tools for surveillance of adult yellow fever ... baited trapping systems for sampling outdoor mosquito populations in ...
Hemorrhagic Fever with Renal Syndrome (Korean Hemorrhagic Fever).
1986-07-23
fever , chills, nausea, headache and muscle ache in July 1985. One day after admission he developed petechial haemorrhage over his body and limbs and in...ftOA179 565 NENORNAGIC FEVER WI TH RENAL SYNDOMNE (KOREAN HEMORRHAIC FEVER )(U) KOREN UNIV SEOUL COLL OF MEDICINE N N LEE 23 JUL " DAD7-94-G-4616...34,, , " S , S S .S =. 5 5 . S S S * B M Lfl IC) uIeuCc FVM WITH RENAL SYNDR~OME (KOREAN EMORRHAGIC FEVER ) ANNUAL AND FINAL REPORT S HO WANG LIZB N.D. 5
Gupta, Nidhi; Mehta, Nishant; Gupta, Preety; Arora, Vikram; Setia, Priyanka
2015-01-01
Ebola viral fever, a highly contagious haemorrhagic disease has today become a major public health concern in the developing countries worldwide. The purpose of this study was to assess knowledge among dental practitioners regarding Ebola Haemorrhagic Fever (Ebola HF) in Tricity, (Chandigarh, Panchkula and Mohali). A total of 500 private dental practitioners were randomly approached to participate in this cross-sectional survey. A self-structured, closed ended questionnaire was administered to each participant to record demographic and professional characteristics followed by their knowledge regarding Ebola HF. Knowledge section included questions related to communicability; symptomatology and diagnostics; at-risk individuals; prevention and treatment; and, virus characteristics of Ebola HF. The results were expressed in percentages. Multivariable linear regression analysis was carried out to assess the association of participants's demographic and professional characteristics with the knowledge scores. Statistically significant difference was seen when mean knowledge scores were compared based on the locality and qualification of the participants (P < 0.05). Dental practitioners from urban areas with higher qualification had better knowledge yet there were notable deficiencies regarding the virus characteristics, diagnostics, elimination and treatment.
Two cases of Hantavirus infection in Crimean-Congo Haemorrhagic Fever endemic region
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Mustafa Sünbül
2012-09-01
Full Text Available Crimean-Congo Hemorrhagic Fever (CCHF and Leptospirosis are endemic in our region. Hantavirus infections may beconfused with similar clinical picture zoonotic infections. Two patients with fever, malaise, cough, phlegm, nausea, vomiting,thrombocytopenia, renal failure, elevated transaminases, and a history of mouse contact were hospitalized in ourclinic with a presumptive diagnosis of leptospirosis, pneumonia, CCHF and Hantavirus infections. Empirical antibiotictreatment was initiated and CCHF and leptospirosis was ruled out with laboratory tests. Hantavirus immunoglobulin(Ig-G and Ig-M antibodies were detected positive by immunofluorescent antibody (IFA method in both cases but,Dobrova virus was detected in only one patient with immunoblotting methods. Both patients were discharged aftertreatment. Hantavirus infections may be misdiagnosed as zoonotic infections since they have similar clinical picture. Itshould be considered in the differential diagnosis of patients with a history of contact with mouse. J Microbiol Infect Dis2012; 2(3: 117-120Key words: Hantavirus, hemorrhagic fever, renal syndrome, pulmonary syndrome
Lihoradova, Olga A; Indran, Sabarish V; Kalveram, Birte; Lokugamage, Nandadeva; Head, Jennifer A; Gong, Bin; Tigabu, Bersabeh; Juelich, Terry L; Freiberg, Alexander N; Ikegami, Tetsuro
2013-01-01
Rift Valley fever virus (RVFV; genus Phlebovirus, family Bunyaviridae) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. MP-12 strain, a live-attenuated candidate vaccine, is attenuated in the M- and L-segments, but the S-segment retains the virulent phenotype. MP-12 was manufactured as an Investigational New Drug vaccine by using MRC-5 cells and encodes a functional NSs gene, the major virulence factor of RVFV which 1) induces a shutoff of the host transcription, 2) inhibits interferon (IFN)-β promoter activation, and 3) promotes the degradation of dsRNA-dependent protein kinase (PKR). MP-12 lacks a marker for differentiation of infected from vaccinated animals (DIVA). Although MP-12 lacking NSs works for DIVA, it does not replicate efficiently in type-I IFN-competent MRC-5 cells, while the use of type-I IFN-incompetent cells may negatively affect its genetic stability. To generate modified MP-12 vaccine candidates encoding a DIVA marker, while still replicating efficiently in MRC-5 cells, we generated recombinant MP-12 encoding Punta Toro virus Adames strain NSs (rMP12-PTNSs) or Sandfly fever Sicilian virus NSs (rMP12-SFSNSs) in place of MP-12 NSs. We have demonstrated that those recombinant MP-12 viruses inhibit IFN-β mRNA synthesis, yet do not promote the degradation of PKR. The rMP12-PTNSs, but not rMP12-SFSNSs, replicated more efficiently than recombinant MP-12 lacking NSs in MRC-5 cells. Mice vaccinated with rMP12-PTNSs or rMP12-SFSNSs induced neutralizing antibodies at a level equivalent to those vaccinated with MP-12, and were efficiently protected from wild-type RVFV challenge. The rMP12-PTNSs and rMP12-SFSNSs did not induce antibodies cross-reactive to anti-RVFV NSs antibody and are therefore applicable to DIVA. Thus, rMP12-PTNSs is highly efficacious, replicates efficiently in MRC-5 cells, and encodes a DIVA marker, all of which are
Acute Compressive Ulnar Neuropathy in a Patient of Dengue Fever: An Unusual Presentation
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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.
T Cell-Mediated Immunity towards Yellow Fever Virus and Useful Animal Models.
Watson, Alan M; Klimstra, William B
2017-04-11
The 17D line of yellow fever virus vaccines is among the most effective vaccines ever created. The humoral and cellular immunity elicited by 17D has been well characterized in humans. Neutralizing antibodies have long been known to provide protection against challenge with a wild-type virus. However, a well characterized T cell immune response that is robust, long-lived and polyfunctional is also elicited by 17D. It remains unclear whether this arm of immunity is protective following challenge with a wild-type virus. Here we introduce the 17D line of yellow fever virus vaccines, describe the current state of knowledge regarding the immunity directed towards the vaccines in humans and conclude with a discussion of animal models that are useful for evaluating T cell-mediated immune protection to yellow fever virus.
T Cell-Mediated Immunity towards Yellow Fever Virus and Useful Animal Models
Watson, Alan M.; Klimstra, William B.
2017-01-01
The 17D line of yellow fever virus vaccines is among the most effective vaccines ever created. The humoral and cellular immunity elicited by 17D has been well characterized in humans. Neutralizing antibodies have long been known to provide protection against challenge with a wild-type virus. However, a well characterized T cell immune response that is robust, long-lived and polyfunctional is also elicited by 17D. It remains unclear whether this arm of immunity is protective following challenge with a wild-type virus. Here we introduce the 17D line of yellow fever virus vaccines, describe the current state of knowledge regarding the immunity directed towards the vaccines in humans and conclude with a discussion of animal models that are useful for evaluating T cell-mediated immune protection to yellow fever virus. PMID:28398253
Functional analysis of replication determinantsin classical swine fever virus
DEFF Research Database (Denmark)
Hadsbjerg, Johanne
and animal pathogens should facilitate finding new approaches for efficient disease control. The principal aim of this thesis is to characterise determinants involved in the replication of classical swine fever virus (CSFV). Classical swine fever is a highly contagious virus disease of domestic pigs and wild...... in cell culture. Knowledge of these sequence variations and putative long-range interactions will provide valuable insights into mechanisms underlying virustranslation and replication. In manuscript 3, a selection marker has been inserted into a CSFV-based replicon making it suitable for screening...
2012-11-16
... Grant of Co-Exclusive License: Veterinary Vaccines for Rift Valley Fever Virus AGENCY: Centers for... Valley Fever Virus Utilizing Reverse Genetics,'' US Provisional Application 61/042,987, filed 4/7/2008, entitled ``Recombinant Rift Valley Fever (RVF) Viruses and Method of Use,'' PCT Application PCT/US2008...
Molecular characterization of African swine fever virus in apparently ...
African Journals Online (AJOL)
African swine fever (ASF) is a highly lethal and economically significant disease of domestic pigs in Uganda where outbreaks regularly occur. There is neither a vaccine nor treatment available for ASF control. Twenty two African swine fever virus (ASFV) genotypes (I - XXII) have been identified based on partial sequencing ...
Ahmed, J.; Bouloy, M.; Ergonul, O.; Fooks, A.R.; Paweska, J.; Chevalier, V.; Drosten, C.; Moormann, R.J.M.; Tordo, N.; Vatansever, Z.; Calistri, P.; Estrada-Pena, A.; Mirazimi, A.; Unger, H.; Yin, H.; Seitzer, U.
2009-01-01
Arboviruses are arthropod-borne viruses, which include West Nile fever virus (WNFV), a mosquito-borne virus, Rift Valley fever virus (RVFV), a mosquito-borne virus, and Crimean-Congo haemorrhagic fever virus (CCHFV), a tick-borne virus. These arthropod-borne viruses can cause disease in different
Severe fever with thrombocytopenia syndrome, an emerging tick-borne zoonosis.
Liu, Quan; He, Biao; Huang, Si-Yang; Wei, Feng; Zhu, Xing-Quan
2014-08-01
Severe fever with thrombocytopenia syndrome (SFTS) is an emerging haemorrhagic fever that was first described in rural areas of China. The causative agent, SFTS virus (SFTSV), is a novel phlebovirus in the Bunyaviridae family. Since the first report in 2010, SFTS has been found in 11 provinces of China, with about 2500 reported cases, and an average case-fatality rate of 7·3%. The disease was also reported in Japan and Korea in 2012; Heartland virus, another phlebovirus genetically closely related to SFTSV, was isolated from two patients in the USA. The disease has become a substantial risk to public health, not only in China, but also in other parts of the world. The virus could undergo rapid evolution by gene mutation, reassortment, and homologous recombination in tick vectors and vertebrate reservoir hosts. No specific treatment of SFTS is available, and avoiding tick bites is an important measure to prevent the infection and transmission of SFTSV. This Review provides information on the molecular characteristics and ecology of this emerging tick-borne virus and describes the epidemiology, clinical signs, pathogenesis, diagnosis, treatment, and prevention of human infection with SFTSV. Copyright © 2014 Elsevier Ltd. All rights reserved.
International Nuclear Information System (INIS)
Van Dijk, A.A.; Huismans, H.
1982-01-01
Virions of bluetongue virus (BTV), epizootic haemorrhagic disease virus (EHDV) and African horsesickness virus (AHSV) can be converted to core particles by treatment with chymotrypsin and magnesium. The conversion is characterized by the removal of the 2 outer capsid polypeptides of the virion. The loss of these 2 proteins results in an increase in density from 1,36 g/ml to 1,40 g/ml on CsCl gradients. The BTV, EHDV and AHSV core particles have an associated double-stranded RNA dependent RNA transcriptase that appears to transcribe mRNA optimally at 28 degrees Celsius. It was found, at least in the case of BTV, that this low temperature preference is not an intrinsic characteristic of the transcriptase, but is due to a temperature-dependent inhibition of transcription at high core concentrations
Kading, Rebekah C; Kityo, Robert M; Mossel, Eric C; Borland, Erin M; Nakayiki, Teddie; Nalikka, Betty; Nyakarahuka, Luke; Ledermann, Jeremy P; Panella, Nicholas A; Gilbert, Amy T; Crabtree, Mary B; Peterhans, Julian Kerbis; Towner, Jonathan S; Amman, Brian R; Sealy, Tara K; Nichol, Stuart T; Powers, Ann M; Lutwama, Julius J; Miller, Barry R
2018-01-01
Introduction: A number of arboviruses have previously been isolated from naturally-infected East African bats, however the role of bats in arbovirus maintenance is poorly understood. The aim of this study was to investigate the exposure history of Ugandan bats to a panel of arboviruses. Materials and methods: Insectivorous and fruit bats were captured from multiple locations throughout Uganda during 2009 and 2011-2013. All serum samples were tested for neutralizing antibodies against West Nile virus (WNV), yellow fever virus (YFV), dengue 2 virus (DENV-2), Zika virus (ZIKV), Babanki virus (BBKV), and Rift Valley fever virus (RVFV) by plaque reduction neutralization test (PRNT). Sera from up to 626 bats were screened for antibodies against each virus. Results and Discussion: Key findings include the presence of neutralizing antibodies against RVFV in 5/52 (9.6%) of little epauletted fruit bats ( Epomophorus labiatus ) captured from Kawuku and 3/54 (5.6%) Egyptian rousette bats from Kasokero cave. Antibodies reactive to flaviviruses were widespread across bat taxa and sampling locations. Conclusion: The data presented demonstrate the widespread exposure of bats in Uganda to arboviruses, and highlight particular virus-bat associations that warrant further investigation.
Scott, Tristan; Paweska, Janusz T; Arbuthnot, Patrick; Weinberg, Marc S
2012-01-01
Rift Valley fever virus (RVFV), a member of the Bunyaviridae family, may cause severe hepatitis, encephalitis and haemorrhagic fever in humans. There are currently no available licensed vaccines or therapies to treat the viral infection in humans. RNA interference (RNAi)-based viral gene silencing offers a promising approach to inhibiting replication of this highly pathogenic virus. The small (S) segment of the RVFV tripartite genome carries the genetic determinates for pathogenicity during infection. This segment encodes the non-structural S (NSs) and essential nucleocapsid (N) genes. To advance RNAi-based inhibition of RVFV replication, we designed several Pol III short hairpin RNA (shRNA) expression cassettes against the NSs and N genes, including a multimerized plasmid vector that included four shRNA expression cassettes. Effective target silencing was demonstrated using full- and partial-length target reporter assays, and confirmed by western blot analysis of exogenous N and NSs expression. Small RNA northern blots showed detectable RNAi guide strand formation from single and multimerized shRNA constructs. Using a cell culture model of RVFV replication, shRNAs targeting the N gene decreased intracellular nucleocapsid protein concentration and viral replication. The shRNAs directed against the NSs gene reduced NSs protein concentrations and alleviated NSs-mediated cytotoxicity, which may be caused by host transcription suppression. These data are the first demonstration that RNAi activators have a potential therapeutic benefit for countering RVFV infection.
General introduction into the Ebola virus biology and disease.
Zawilińska, Barbara; Kosz-Vnenchak, Magdalena
2014-01-01
Epidemic of Ebola hemorrhagic fever which appeared in the countries of West Africa in 2014, is the largest outbreak which occurred so far. The virus causing this epidemic, Zaire Ebolavirus (ZEBOV), along with four other species of Ebolaviruses is classified to the genus Ebolavirus in the family Filoviridae. ZEBOV is one of the most virulent pathogens among the viral haemorrhagic fevers, and case fatality rates up to 90% have been reported. Mortality is the result of multi-organ failure and severe bleeding complications. The aim of this review is to present the general characteristics of the virus and its biological properties, pathogenicity and epidemiology, with a focus on laboratory methods used in the diagnosis of these infections.
Recognising haemorrhagic rash in children with fever: a survey of parents' knowledge.
Aurel, M; Dubos, F; Motte, B; Pruvost, I; Leclerc, F; Martinot, A
2011-07-01
Early recognition and treatment of meningococcal disease improves its outcome. Haemorrhagic rash is one of the most specific signs that parents can learn to recognise. To determine the percentage of parents able to recognise a haemorrhagic rash and perform the tumbler test. 123 parents of children consulting for mild injuries were interviewed about the significance and recognition of haemorrhagic rash in febrile children. Although 88% of parents undressed their children when they were febrile, it was never to look specifically for a skin rash. Only 7% (95% CI 3% to 12%) were able to recognise a petechial rash and knew the tumbler test. Information campaigns about the significance of haemorrhagic rash and about the tumbler test are needed.
Enzootic transmission of yellow fever virus, Venezuela.
Auguste, Albert J; Lemey, Philippe; Bergren, Nicholas A; Giambalvo, Dileyvic; Moncada, Maria; Morón, Dulce; Hernandez, Rosa; Navarro, Juan-Carlos; Weaver, Scott C
2015-01-01
Phylogenetic analysis of yellow fever virus (YFV) strains isolated from Venezuela strongly supports YFV maintenance in situ in Venezuela, with evidence of regionally independent evolution within the country. However, there is considerable YFV movement from Brazil to Venezuela and between Trinidad and Venezuela.
2012-11-16
... Grant of Exclusive License: Veterinary Vaccines for Rift Valley Fever Virus AGENCY: Centers for Disease..., filed 12/21/2007, entitled ``Development of Rift Valley Fever Virus Utilizing Reverse Genetics,'' US... (RVF) Viruses and Method of Use,'' PCT Application PCT/US2008/ 087023, filed 12/16/2008, entitled...
Surveillance of Rift Valley Fever in Iran between 2001 and 2011
Directory of Open Access Journals (Sweden)
Sadegh CHINIKAR
2013-06-01
Full Text Available Rift Valley fever virus (RVFV is an acute zoonotic viral disease that mostly affects ruminants with an occasional spillover as human infection. Following the outbreak of RVF in Saudi Arabia in 2000, surveillance of both animal and human population in Iran increased until 2011. During this period 1206 ovine, 405 caprine, 325 bovine and 28 camel samples were tested for RVFV in nine provinces in Iran. None of these samples tested IgG positive. Moreover, amongst 37 clinically suspected human cases of patients with RVF symptoms, none of these samples tested positive for RVFV. Despite the fact that no positive cases in human or animal populations were identified in Iran, surveillance and monitoring of viral haemorrhagic fevers including RVFV will continue.
Surveillance of Rift Valley Fever in Iran between 2001 and 2011
Directory of Open Access Journals (Sweden)
Sadegh CHINIKAR
2013-04-01
Full Text Available Rift Valley fever virus (RVFV is an acute zoonotic viral disease that mostly affects ruminants with an occasional spillover as human infection. Following the outbreak of RVF in Saudi Arabia in 2000, surveillance of both animal and human population in Iran increased until 2011. During this period 1206 ovine, 405 caprine, 325 bovine and 28 camel samples were tested for RVFV in nine provinces in Iran. None of these samples tested IgG positive. Moreover, amongst 37 clinically suspected human cases of patients with RVF symptoms, none of these samples tested positive for RVFV. Despite the fact that no positive cases in human or animal populations were identified in Iran, surveillance and monitoring of viral haemorrhagic fevers including RVFV will continue.
Hiding the evidence: two strategies for innate immune evasion by hemorrhagic fever viruses.
Hastie, Kathryn M; Bale, Shridhar; Kimberlin, Christopher R; Saphire, Erica Ollmann
2012-04-01
The innate immune system is one of the first lines of defense against invading pathogens. Pathogens have, in turn, evolved different strategies to counteract these responses. Recent studies have illuminated how the hemorrhagic fever viruses Ebola and Lassa fever prevent host sensing of double-stranded RNA (dsRNA), a key hallmark of viral infection. The ebolavirus protein VP35 adopts a unique bimodal configuration to mask key cellular recognition sites on dsRNA. Conversely, the Lassa fever virus nucleoprotein actually digests the dsRNA signature. Collectively, these structural and functional studies shed new light on the mechanisms of pathogenesis of these viruses and provide new targets for therapeutic intervention. Copyright © 2012. Published by Elsevier B.V.
Chang, Jinhong; Warren, Travis K; Zhao, Xuesen; Gill, Tina; Guo, Fang; Wang, Lijuan; Comunale, Mary Ann; Du, Yanming; Alonzi, Dominic S; Yu, Wenquan; Ye, Hong; Liu, Fei; Guo, Ju-Tao; Mehta, Anand; Cuconati, Andrea; Butters, Terry D; Bavari, Sina; Xu, Xiaodong; Block, Timothy M
2013-06-01
Host cellular endoplasmic reticulum α-glucosidases I and II are essential for the maturation of viral glycosylated envelope proteins that use the calnexin mediated folding pathway. Inhibition of these glycan processing enzymes leads to the misfolding and degradation of these viral glycoproteins and subsequent reduction in virion secretion. We previously reported that, CM-10-18, an imino sugar α-glucosidase inhibitor, efficiently protected the lethality of dengue virus infection of mice. In the current study, through an extensive structure-activity relationship study, we have identified three CM-10-18 derivatives that demonstrated superior in vitro antiviral activity against representative viruses from four viral families causing hemorrhagic fever. Moreover, the three novel imino sugars significantly reduced the mortality of two of the most pathogenic hemorrhagic fever viruses, Marburg virus and Ebola virus, in mice. Our study thus proves the concept that imino sugars are promising drug candidates for the management of viral hemorrhagic fever caused by variety of viruses. Copyright © 2013 Elsevier B.V. All rights reserved.
Virulence determinants within the E2 glycoprotein of Classical Swine Fever Virus
DEFF Research Database (Denmark)
Johnston, Camille Melissa; Fahnøe, Ulrik; Lohse, Louise
Classical Swine Fever is a highly contagious disease of pigs caused by Classical Swine Fever Virus (CSFV), a member of the pestivirus genus within the family Flaviviridae. The E2 glycoprotein of CSFV has been shown to be an important factor for the virulence of the virus. In a recent study, we have......Kos (with the SL motif). The results indicate that the E2 residues 763-64 play an important role in CSFV virulence....
Yellow Fever Virus Vaccine–associated Deaths in Young Women 1
Seligman, Stephen J.
2011-01-01
Yellow fever vaccine–associated viscerotropic disease is a rare sequela of live-attenuated virus vaccine. Elderly persons and persons who have had thymectomies have increased susceptibility. A review of published and other data suggested a higher than expected number of deaths from yellow fever vaccine–associated viscerotropic disease among women 19–34 years of age without known immunodeficiency.
Close Relationship of Ruminant Pestiviruses and Classical Swine Fever Virus
Postel, Alexander; Schmeiser, Stefanie; Oguzoglu, Tuba Cigdem; Indenbirken, Daniela; Alawi, Malik; Fischer, Nicole; Grundhoff, Adam
2015-01-01
To determine why serum from small ruminants infected with ruminant pestiviruses reacted positively to classical swine fever virus (CSFV)–specific diagnostic tests, we analyzed 2 pestiviruses from Turkey. They differed genetically and antigenically from known Pestivirus species and were closely related to CSFV. Cross-reactions would interfere with classical swine fever diagnosis in pigs. PMID:25811683
Asambe, A; Sackey, A K B; Tekdek, L B
2018-03-01
This study investigated the prevalence of African swine fever virus (ASFV) and classical swine fever virus (CSFV) antibodies in pigs in Benue State, Nigeria. Serum samples were collected from a total of 460 pigs, including 416 from 74 piggeries and 44 from Makurdi slaughter slab. The samples were analysed using indirect enzyme-linked immunosorbent assay (ELISA) test kit to detect the presence of ASFV antibodies, while competitive ELISA test kit was used to detect antibodies to CSFV. Our findings showed a total ASF prevalence of 13 (2.8%), while prevalences of 7 (1.7%) and 6 (13.6%) were observed in piggeries and in Makurdi slaughter slab, respectively. However, no CSFV antibody sera were detected in this study. Relatively higher ASFV antibody-positive pigs were detected in the slaughter slab than in piggeries. The difference in prevalence of ASF between the two locations was significantly associated (p = 0.017). These findings suggest the presence of ASFV antibody-positive pig in Benue State, Nigeria. Continuous surveillance and monitoring of these diseases among pigs in Nigeria to prevent any fulminating outbreak are recommended.
Seroprevalence of sandfly fever virus infection in military personnel on the western border of Iran
Directory of Open Access Journals (Sweden)
Ramin Shiraly
2017-01-01
Full Text Available Summary: Military troops deployed to endemic areas are at risk of contracting sandfly fever, an arthropod-borne viral infection. Although typically a self-limited disease, sandfly fever can cause significant morbidity and loss of function among soldiers. We conducted this study to determine the extent of past SFV infection in a group of healthy Iranian military personnel in Ilam province on the western border of Iran. A total of 201 serum samples were tested by indirect immunofluorescence assay (IFA to detect four common sandfly fever virus serotypes. Demographic data were also collected. Overall, 37 samples (18.4% were positive for specific IgG antibodies to sandfly viruses. Sandfly fever Sicilian virus (SFSV and sandfly fever Naples virus (SFNV were the most common serotypes. A positive test was inversely related to nativity (P < 0.01 but was not associated with age (P = 0.163, duration of presence in the border region (P = 0.08 or employment status (P = 0.179.Our findings indicate that past SFV infection is common among military personnel in the western border region of Iran, a Leishmania-endemic region. Therefore, it should be considered in the differential diagnosis of troops presenting with acute febrile illness in similar settings. Keywords: Sandfly fever, Virus, Past infection, Military personnel
DEFF Research Database (Denmark)
Skall, Helle Frank; Olesen, Niels Jørgen; Mellergaard, Stig
2005-01-01
In order to analyse the occurrence of viral haemorrhagic septicaerma virus (VHSV) in the marine waters around Denmark, staff from the Danish Institute for Food and Veterinary Research participated in 5 research cruises during 1998 to 2002 as a follow-up to 4 research cruises performed in 1996...
Detection of yellow fever virus genomes from four imported cases in China.
Cui, Shujuan; Pan, Yang; Lyu, Yanning; Liang, Zhichao; Li, Jie; Sun, Yulan; Dou, Xiangfeng; Tian, Lili; Huo, Da; Chen, Lijuan; Li, Xinyu; Wang, Quanyi
2017-07-01
Yellow fever virus (YFV), as the first proven human-pathogenic virus, is still a major public health problem with a dramatic upsurge in recent years. This is a report on four imported cases of yellow fever virus into China identified by whole genome sequencing. Phylogenetic analysis was performed and the results showed that these four viruses were highly homologous with Angola 71 strains (AY968064). In addition, effective mutations of amino acids were not observed in the E protein domain of four viruses, thus confirming the effectiveness of the YFV-17D vaccine (X03700). Although there is low risk of local transmission in most part of China, the increasing public health risk of YF caused by international exchange should not be ignored. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Crimean Congo Hemorrhagic Fever Virus and Alkhurma (Alkhumra) Virus in Ticks in Djibouti.
Horton, Katherine C; Fahmy, Nermeen T; Watany, Noha; Zayed, Alia; Mohamed, Abro; Ahmed, Ammar Abdo; Rollin, Pierre E; Dueger, Erica L
2016-10-01
Crimean Congo hemorrhagic fever virus and Alkhumra virus, not previously reported in Djibouti, were detected among 141 (infection rate = 15.7 per 100, 95% CI: 13.4-18.1) tick pools from 81 (37%) cattle and 2 (infection rate = 0.2 per 100, 95% CI: 0.0-0.7) tick pools from 2 (1%) cattle, respectively, collected at an abattoir in 2010 and 2011.
Zhang, S; Zheng, B; Wang, T; Li, A; Wan, J; Qu, J; Li, C H; Li, D; Liang, M
Severe fever with thrombocytopenia syndrome virus (SFTSV) is a newly identified Phlebovirus that causes severe fever with thrombocytopenia syndrome. Our study demonstrated that SFTSV NSs functioned as IFN antagonist mainly by suppressing TBK1/IKKε-IRF3 signaling pathway. NSs interacted with and relocalized TANK-binding kinase 1 (TBK1) into NSs-induced cytoplasmic structures and this interaction could effectively inhibit downstream phosphorylation and dimerization of interferon regulatory factor 3 (IRF3), resulting in the suppression of antiviral signaling and IFN induction. Functional sites of SFTSV NSs binding with TBK1 were then studied and results showed that NSs had lost their IFN-inhibiting activity after deleting the 25 amino acids in N-terminal. Furthermore, the mechanism of Rift Valley fever virus (RVFV) NSs blocking IFN-β response were also investigated. Preliminary results showed that RVFV NSs proteins could neither interact nor co-localize with TBK1 in cytoplasm, but suppressed its expression levels, phosphorylation and dimerization of IRF3 in the subsequent steps, resulting in inhibition of the IFN-β production. Altogether, our data demonstrated the probable mechanism used by SFTSV to inhibit IFN responses which was different from RVFV and pointed toward a novel mechanism for RVFV suppressing IFN responses.
Al-Abri, Seif S; Abaidani, Idris Al; Fazlalipour, Mehdi; Mostafavi, Ehsan; Leblebicioglu, Hakan; Pshenichnaya, Natalia; Memish, Ziad A; Hewson, Roger; Petersen, Eskild; Mala, Peter; Nhu Nguyen, Tran Minh; Rahman Malik, Mamunur; Formenty, Pierre; Jeffries, Rosanna
2017-05-01
Crimean-Congo haemorrhagic fever (CCHF) is the most widespread, tick-borne viral disease affecting humans. The disease is endemic in many regions, such as Africa, Asia, Eastern and Southern Europe, and Central Asia. Recently, the incidence of CCHF has increased rapidly in the countries of the World Health Organization Eastern Mediterranean Region (WHO EMR), with sporadic human cases and outbreaks of CCHF being reported from a number of countries in the region. Despite the rapidly growing incidence of the disease, there are currently no accurate data on the burden of the disease in the region due to the different surveillance systems used for CCHF in these countries. In an effort to increase our understanding of the epidemiology and risk factors for the transmission of the CCHF virus (CCHFV; a Nairovirus of the family Bunyaviridae) in the WHO EMR, and to identify the current knowledge gaps that are hindering effective control interventions, a sub-regional meeting was organized in Muscat, Oman, from December 7 to 9, 2015. This article summarizes the current knowledge of the disease in the region, identifies the knowledge gaps that present challenges for the prevention and control of CCHFV, and details a strategic framework for research and development activities that would be necessary to curb the ongoing and new threats posed by CCHFV. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.
Directory of Open Access Journals (Sweden)
Seif S. Al-Abri
2017-05-01
Full Text Available Crimean-Congo haemorrhagic fever (CCHF is the most widespread, tick-borne viral disease affecting humans. The disease is endemic in many regions, such as Africa, Asia, Eastern and Southern Europe, and Central Asia. Recently, the incidence of CCHF has increased rapidly in the countries of the World Health Organization Eastern Mediterranean Region (WHO EMR, with sporadic human cases and outbreaks of CCHF being reported from a number of countries in the region. Despite the rapidly growing incidence of the disease, there are currently no accurate data on the burden of the disease in the region due to the different surveillance systems used for CCHF in these countries. In an effort to increase our understanding of the epidemiology and risk factors for the transmission of the CCHF virus (CCHFV; a Nairovirus of the family Bunyaviridae in the WHO EMR, and to identify the current knowledge gaps that are hindering effective control interventions, a sub-regional meeting was organized in Muscat, Oman, from December 7 to 9, 2015. This article summarizes the current knowledge of the disease in the region, identifies the knowledge gaps that present challenges for the prevention and control of CCHFV, and details a strategic framework for research and development activities that would be necessary to curb the ongoing and new threats posed by CCHFV.
Kovaliski, John; Sinclair, Ron; Mutze, Greg; Peacock, David; Strive, Tanja; Abrantes, Joana; Esteves, Pedro J.; Holmes, Edward C.
2013-01-01
Rabbit Haemorrhagic Disease Virus (RHDV) was introduced into Australia in 1995 as a biological control agent against the wild European rabbit (Oryctolagus cuniculus). We evaluated its evolution over a 16 year period (1995–2011) by examining 50 isolates collected throughout Australia, as well as the original inoculum strains. Phylogenetic analysis of capsid protein VP60 sequences of the Australian isolates, compared to those sampled globally, revealed that they form a monophyletic group with t...
ATKINS, E; HUANG, W C
1958-03-01
A substance with pyrogenic properties appears in the blood streams of rabbits made febrile by the intravenous inoculation of the PR8 strain of influenza A and Newcastle disease viruses (NDV). By means of a technique involving passive transfer of sera from animals given virus to recipient rabbits, the titer of circulating pyrogen was found to be closely correlated with the course of fever produced by virus. Certain properties of the pyrogen are described which differentiate it from the originally injected virus and suggest that the induced pyrogen is of endogenous origin. These properties resemble those of endogenous pyrogens occurring in other forms of experimental fever. The source of virus-induced pyrogen is unknown. In vitro incubation of virus with various constituents of the circulation did not result in the appearance of endogenous pyrogen. Granulocytopenia induced by HN(2) failed to influence either fever or the production of endogenous pyrogen in rabbits injected with NDV. Similarly, the intraperitoneal inoculation of NDV into prepared exudates did not modify the febrile response. These findings do not lend support to the possibility that the polymorphonuclear leukocyte is a significant source of endogenous pyrogen in virus-induced fever. It is concluded that the liberation of an endogenous pyrogen from some as yet undefined source is an essential step in the pathogenesis of fever caused by the influenza group of viruses.
An in vivo system for directed experimental evolution of rabbit haemorrhagic disease virus.
Hall, Robyn N; Capucci, Lorenzo; Matthaei, Markus; Esposito, Simona; Kerr, Peter J; Frese, Michael; Strive, Tanja
2017-01-01
The calicivirus Rabbit haemorrhagic disease virus (RHDV) is widely used in Australia as a biocontrol agent to manage wild European rabbit (Oryctolagus cuniculus) populations. However, widespread herd immunity limits the effectiveness of the currently used strain, CAPM V-351. To overcome this, we developed an experimental platform for the selection and characterisation of novel RHDV strains. As RHDV does not replicate in cell culture, variant viruses were selected by serially passaging a highly virulent RHDV field isolate in immunologically naïve laboratory rabbits that were passively immunised 18-24 hours post-challenge with a neutralising monoclonal antibody. After seven passages, two amino acid substitutions in the P2 domain of the capsid protein became fixed within the virus population. Furthermore, a synonymous substitution within the coding sequence of the viral polymerase appeared and was also maintained in all subsequent passages. These findings demonstrate proof-of-concept that RHDV evolution can be experimentally manipulated to select for virus variants with altered phenotypes, in this case partial immune escape.
Gale, P; Brouwer, A; Ramnial, V; Kelly, L; Kosmider, R; Fooks, A R; Snary, E L
2010-02-01
Expert opinion was elicited to undertake a qualitative risk assessment to estimate the current and future risks to the European Union (EU) from five vector-borne viruses listed by the World Organization for Animal Health. It was predicted that climate change will increase the risk of incursions of African horse sickness virus (AHSV), Crimean-Congo haemorrhagic fever virus (CCHFV) and Rift Valley fever virus (RVFV) into the EU from other parts of the world, with African swine fever virus (ASFV) and West Nile virus (WNV) being less affected. Currently the predicted risks of incursion were lowest for RVFV and highest for ASFV. Risks of incursion were considered for six routes of entry (namely vectors, livestock, meat products, wildlife, pets and people). Climate change was predicted to increase the risk of incursion from entry of vectors for all five viruses to some degree, the strongest effects being predicted for AHSV, CCHFV and WNV. This work will facilitate identification of appropriate risk management options in relation to adaptations to climate change.
Sudeep, A B; Jadi, R S; Mishra, A C
2009-11-01
Ganjam virus (GANV), a member of genus Nairovirus of family Bunyavirdae is of considerable veterinary importance in India. Though, predominantly tick borne, GANV was also isolated from mosquitoes, man and sheep. Neutralizing and complement fixing antibodies to GANV have been detected in animal and human sera collected from different parts of the country. Thirty three strains of GANV have been isolated from India, mainly from Haemaphysalis ticks. The virus replicated in certain vertebrate and mosquito cell lines and found pathogenic to laboratory animals. One natural infection and five laboratory-acquired infections in men were also reported. GANV is antigenically related to Nairobi sheep disease virus (NSDV) of Africa, which is highly pathogenic for sheep and goats causing 70-90 per cent mortality among the susceptible population. Recent molecular studies have demonstrated that GANV is an Asian variant of NSDV and both these viruses are related to the dreaded Crimean Congo haemorrhagic fever (CCHF) group viruses. The versatility of the virus to replicate in different arthropod species, its ability to infect sheep, goat and man makes it an important zoonotic agent.
Li, Su; Wang, Jinghan; Yang, Qian; Naveed Anwar, Muhammad; Yu, Shaoxiong; Qiu, Hua-Ji
2017-07-05
Classical swine fever (CSF), caused by classical swine fever virus (CSFV), is one of the most devastating epizootic diseases of pigs in many countries. Viruses are small intracellular parasites and thus rely on the cellular factors for replication. Fundamental aspects of CSFV-host interactions have been well described, such as factors contributing to viral attachment, modulation of genomic replication and translation, antagonism of innate immunity, and inhibition of cell apoptosis. However, those host factors that participate in the viral entry, assembly, and release largely remain to be elucidated. In this review, we summarize recent progress in the virus-host interactions involved in the life cycle of CSFV and analyze the potential mechanisms of viral entry, assembly, and release. We conclude with future perspectives and highlight areas that require further understanding.
Lam, Tommy Tsan-Yuk; Liu, Wei; Bowden, Thomas A.; Cui, Ning; Zhuang, Lu; Liu, Kun; Zhang, Yao-Yun; Cao, Wu-Chun; Pybus, Oliver G.
2013-01-01
In 2009, a novel Bunyavirus, called severe fever with thrombocytopenia syndrome virus (SFTSV) was identified in the vicinity of Huaiyangshan, China. Clinical symptoms of this zoonotic virus included severe fever, thrombocytopenia, and leukocytopenia, with a mortality rate of ?10%. By the end of 2011 the disease associated with this pathogen had been reported from eleven Chinese provinces and human-to-human transmission suspected. However, current understanding of the evolution and molecular e...
ATKINS, E; HUANG, W C
1958-03-01
Observations have been made on the fever-inducing properties of an endogenous pyrogen found in the circulation of rabbits after the intravenous inoculation of Newcastle disease virus (NDV). When endogenous pyrogen was given to a normal recipient, a biphasic fever was produced which simulated that seen with bacterial endotoxins. With the use of a technique of serial passive transfer, it has been shown that the "double-humped" response results from two separate actions of the injected pyrogen. The first of these appears to be a direct stimulation of the thermoregulatory centers. The second involves the release of further endogenous pyrogen in the normal recipient to cause, in turn, the second fever peak. Since the injection of endogenous pyrogen did not produce a significant change in the number of circulating leukocytes, it is inferred that this substance is different from either bacterial or tissue polysaccharides. In rabbits rendered tolerant by a previous injection of virus the second fever peak failed to appear and the response to endogenous pyrogen was monophasic. Evidence indicates that the absence of a second fever peak in the tolerant recipient was not due to rise in temperature on the preceding day of virus injection or to the development of either serum inhibitors or tolerance to virus itself. It is postulated that prior mobilization of endogenous pyrogen by virus may have modified the ability of the tolerant recipient to liberate further amounts of this substance in response to an injection of endogenous pyrogen.
Ocular manifestations of dengue fever in an East Indian epidemic.
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.
Neimanis, A S; Ahola, H; Zohari, S; Larsson Pettersson, U; Bröjer, C; Capucci, L; Gavier-Widén, D
2018-02-01
Incursion of rabbit haemorrhagic disease virus (RHDV) into Sweden was documented in 1990 and it is now considered endemic in wild rabbit (Oryctolagus cuniculus) populations. Rabbit haemorrhagic disease virus 2 (RHDV2), a new, related lagovirus was first detected in France in 2010, and has spread rapidly throughout Europe and beyond. However, knowledge of RHDV2 in northern Europe is sporadic and incomplete, and in Sweden, routinely available diagnostic methods to detect rabbit haemorrhagic disease (RHD) do not distinguish between types of virus causing disease. Using RHDV2-specific RT-qPCR, sequencing of the VP60 gene and immunological virus typing of archived and prospective case material from the National Veterinary Institute's (SVA) wildlife disease surveillance programme and diagnostic pathology service, we describe the emergence of RHDV2 in Sweden in both wild and domestic rabbits. The earliest documented outbreak occurred on 22 May 2013, and from May 2013 to May 2016, 10 separate incidents of RHDV2 were documented from six different municipalities in the southern half of Sweden. Phylogenetic analysis of the VP60 gene shows clear clustering of Swedish isolates into three separate clusters within two different clades according to geographic location and time, suggesting viral evolution, multiple introduction events or both. Almost all cases of RHD examined by SVA from May 2013 to May 2016 were caused by RHDV2, suggesting that RHDV2 may be replacing RHDV as the predominant cause of RHD in Sweden. © 2017 Blackwell Verlag GmbH.
Directory of Open Access Journals (Sweden)
Mariana Gandini
2011-08-01
Full Text Available Flaviviruses cause severe acute febrile and haemorrhagic infections, including dengue and yellow fever and the pathogenesis of these infections is caused by an exacerbated immune response. Dendritic cells (DCs are targets for dengue virus (DENV and yellow fever virus (YF replication and are the first cell population to interact with these viruses during a natural infection, which leads to an induction of protective immunity in humans. We studied the infectivity of DENV2 (strain 16681, a YF vaccine (YF17DD and a chimeric YF17D/DENV2 vaccine in monocyte-derived DCs in vitro with regard to cell maturation, activation and cytokine production. Higher viral antigen positive cell frequencies were observed for DENV2 when compared with both vaccine viruses. Flavivirus-infected cultures exhibited dendritic cell activation and maturation molecules. CD38 expression on DCs was enhanced for both DENV2 and YF17DD, whereas OX40L expression was decreased as compared to mock-stimulated cells, suggesting that a T helper 1 profile is favoured. Tumor necrosis factor (TNF-α production in cell cultures was significantly higher in DENV2-infected cultures than in cultures infected with YF17DD or YF17D/DENV. In contrast, the vaccines induced higher IFN-α levels than DENV2. The differential cytokine production indicates that DENV2 results in TNF induction, which discriminates it from vaccine viruses that preferentially stimulate interferon expression. These differential response profiles may influence the pathogenic infection outcome.
DEFF Research Database (Denmark)
Einer-Jensen, Katja; Biacchesi, S.; Stegmann, Anders
. By a reverse genetics approach using the related novirrhabdovirus infectious hematopoietic necrosis virus (IHNV) as basis, four hybrid IHNV-VHSV variants were generated. These chimeric variants included substitution of the IHNV glyco(G) or nonstrutrual (Nv) protein with the corresponding G or Nv-protein from......Viral haemorrhagic septicaemia virus (VHSV) is the economically most important viral disease in European rainbow trout farming. The virus was introduced to fresh water farms in the 1950ies from a reservoir of VHSV in the marine environment. Isolates from wild marine fish and fresh water farms...... are difficult to distinguish serologically but they show different virulence profiles: marine isolates typically cause little or no mortality in rainbow trout fry following experimental waterborne challenge, while freshwater isolates often kill the majority of the fish. Genetic analysis reveal that the change...
Comparative quantitative monitoring of rabbit haemorrhagic disease viruses in rabbit kittens.
Matthaei, Markus; Kerr, Peter J; Read, Andrew J; Hick, Paul; Haboury, Stephanie; Wright, John D; Strive, Tanja
2014-06-09
Only one strain (the Czech CAPM-v351) of rabbit haemorrhagic disease virus (RHDV) has been released in Australia and New Zealand to control pest populations of the European rabbit O. cuniculus. Antigenic variants of RHDV known as RHDVa strains are reportedly replacing RHDV strains in other parts of the world, and Australia is currently investigating the usefulness of RHDVa to complement rabbit biocontrol efforts in Australia and New Zealand. RHDV efficiently kills adult rabbits but not rabbit kittens, which are more resistant to RHD the younger they are and which may carry the virus without signs of disease for prolonged periods. These different infection patterns in young rabbits may significantly influence RHDV epidemiology in the field and hence attempts to control rabbit numbers. We quantified RHDV replication and shedding in 4-5 week old rabbits using quantitative real time PCR to assess their potential to shape RHDV epidemiology by shedding and transmitting virus. We further compared RHDV-v351 with an antigenic variant strain of RHDVa in kittens that is currently being considered as a potential RHDV strain for future release to improve rabbit biocontrol in Australia. Kittens were susceptible to infection with virus doses as low as 10 ID50. Virus growth, shedding and transmission after RHDVa infection was found to be comparable or non-significantly lower compared to RHDV. Virus replication and shedding was observed in all kittens infected, but was low in comparison to adult rabbits. Both viruses were shed and transmitted to bystander rabbits. While blood titres indicated that 4-5 week old kittens mostly clear the infection even in the absence of maternal antibodies, virus titres in liver, spleen and mesenteric lymph node were still high on day 5 post infection. Rabbit kittens are susceptible to infection with very low doses of RHDV, and can transmit virus before they seroconvert. They may therefore play an important role in RHDV field epidemiology, in
African swine fever is a contagious and often lethal disease for domestic pigs with a significant economic impact on the swine industry. The etiological agent, African swine fever virus (ASFV), is a highly structurally complex double stranded DNA virus. No effective vaccines or antiviral treatment ...
Nairobi sheep disease virus/Ganjam virus.
M D, Baron; B, Holzer
2015-08-01
Nairobi sheep disease virus (NSDV) is a tick-borne virus which causes a severe disease in sheep and goats, and has been responsible for several outbreaks of disease in East Africa. The virus is also found in the Indian subcontinent, where it is known as Ganjam virus. The virus only spreads through the feeding of competent infected ticks, and is therefore limited in its geographic distribution by the distribution of those ticks, Rhipicephalus appendiculata in Africa and Haemaphysalis intermedia in India. Animals bred in endemic areas do not normally develop disease, and the impact is therefore primarily on animals being moved for trade or breeding purposes. The disease caused by NSDV has similarities to several other ruminant diseases, and laboratory diagnosis is necessary for confirmation. There are published methods for diagnosis based on polymerase chain reaction, for virus growth in cell culture and for other simple diagnostic tests, though none has been commercialised. There is no established vaccine against NSDV, although cell-culture attenuated strains have been developed which show promise and could be put into field trials if it were deemed necessary. The virus is closely related to Crimean-Congo haemorrhagic fever virus, and studies on NSDV may therefore be useful in understanding this important human pathogen.
Verdezoto, J; Breard, E; Viarouge, C; Quenault, H; Lucas, P; Sailleau, C; Zientara, S; Augot, D; Zapata, S
2018-02-01
Bluetongue virus (BTV) and Epizootic haemorrhagic disease virus (EHDV) are closely related Orbiviruses that affect domestic and wild ruminants. In Ecuador previous serological studies reported the presence of BTV; however, no data are available about the presence of EHDV. In this study, 295 cattle without symptoms of infection were sampled from two farms located in Andean and Amazonian regions and from a slaughterhouse in the coastal region. ELISA analyses showed high prevalence of BTV (98.9%) and EHDV (81.3%) antibodies, and RT-qPCRs revealed the presence of EHDV (24.1%) and BTV (10.2%) genomes in cattle blood samples. Viral isolation allowed to identify EHDV serotype 1 (EHDV1) and BTV serotypes 9 (BTV9), 13 and 18. These findings suggest that BTV and EHDV are enzootic diseases in Ecuador. © 2017 Blackwell Verlag GmbH.
Directory of Open Access Journals (Sweden)
C Lahariya
2012-01-01
Full Text Available The emerging and re-emerging diseases are posing a great health risk for the last few years. One such category of diseases is viral haemorrhagic fevers (VHFs, which have emerged in the new territories, worldwide. Crimean Congo Hemorrhagic Fever (CCHF cases, for the first time in India, were reported from Gujarat, in January 2011. The emergence of diseases not reported earlier, pose great economic and social challenge, burden health system, and create panic reaction. Nonetheless, with recent experience in control of epidemic diseases, and advances in basic scientific knowledge; the public health community is better prepared for these unexpected events. This review provides information to physicians on CCHF for managing outbreak, and identifies public health measures to prevent emergence and re-emergence of VHFs (including CCHF in future. The authors suggest that though, there are a few challenging and unanswered questions, the public health preparedness still remains the key to control emerging and re-emerging diseases. The countries where virus activities have been reported need to be prepared accordingly.
Kuhn, Susan; Twele-Montecinos, Loreto; MacDonald, Judy; Webster, Patricia; Law, Barbara
2011-01-01
The 17D yellow fever vaccine is a live-virus vaccine that has been in use since the 1940s. The incidence of encephalitis after yellow fever vaccination among young infants is much higher than among children older than nine months of age. Until recently, avoidance of vaccination by breastfeeding women who have received yellow fever vaccine had been based on theoretical grounds only. We report the probable transmission of vaccine strain of yellow fever virus from a mother to her infant through ...
Suzuki, Takashi; Osei, Joseph H; Sasaki, Akihiro; Adimazoya, Michelle; Appawu, Maxwell; Boakye, Daniel; Ohta, Nobuo; Dadzie, Samuel
2016-09-01
Dengue is one of the emerging diseases that can mostly only be controlled by vector control since there is no vaccine for the disease. Although, Dengue has not been reported in Ghana, movement of people from neighbouring countries where the disease has been reported can facilitate transmission of the disease. This study was carried on the University of Ghana campus to determine the risk of transmission of viral haemorrhagic fevers and the insecticide susceptibility status of Ae. aegypti in some sites in Accra, Ghana. Larval surveys were carried to inspect containers within households and estimate larval indices and adult Aedes mosquitoes were collected using human landing collection technique. WHO tube assays was used to assess the insecticide susceptibility status of Aedes mosquitoes. Ae. aegypti were the most prevalent species, 75.5% and followed by Ae. vittatus , 23.9 %. Ae. albopictus and Ae. granti were in smaller numbers. Household index (HI), Breteau index (BI), and container index were calculated as 8.2%, 11.2% and 10.3% respectively with man-vector contact rate of 0.67 bites/man-hour estimated for the area. The mortalities recorded for Ae. aegypti from WHO tube assays was 88%, 94%, 80% and 99% for DDT (4%), deltamethrin (0.05%), lambdacyhalothrin (0.05%) and permethrin (0.75%) respectively. The survey results indicated that the density of Aedes mosquitoes was considered to be sufficient to promote an outbreak of viral haemorrhagic fevers on Legon Campus. Aedes mosquitoes were found to be resistant to DDT, deltamethrin and lamdacyhalothrin, but susceptible to permethrin. This study was supported in part by Japan Initiative for Global Research Network on Infectious Diseases (J-Grid).
Novel bivalent vectored vaccine for control of myxomatosis and rabbit haemorrhagic disease.
Spibey, N; McCabe, V J; Greenwood, N M; Jack, S C; Sutton, D; van der Waart, L
2012-03-24
A novel, recombinant myxoma virus-rabbit haemorrhagic disease virus (RHDV) vaccine has been developed for the prevention of myxomatosis and rabbit haemorrhagic disease (RHD). A number of laboratory studies are described illustrating the safety and efficacy of the vaccine following subcutaneous administration in laboratory rabbits from four weeks of age onwards. In these studies, both vaccinated and unvaccinated control rabbits were challenged using pathogenic strains of RHD and myxoma viruses, and 100 per cent of the vaccinated rabbits were protected against both myxomatosis and RHD.
[Ebola and Marburg hemorrhagic fever viruses: update on filoviruses].
Leroy, E; Baize, S; Gonzalez, J P
2011-04-01
The Ebola and Marburg viruses are the sole members of the Filoviridae family of viruses. They are characterized by a long filamentous form that is unique in the viral world. Filoviruses are among the most virulent pathogens currently known to infect humans. They cause fulminating disease characterized by acute fever followed by generalized hemorrhagic syndrome that is associated with 90% mortality in the most severe forms. Epidemic outbreaks of Marburg and Ebola viruses have taken a heavy toll on human life in Central Africa and devastated large ape populations in Gabon and Republic of Congo. Since their discovery in 1967 (Marburg) and 1976 (Ebola), more than 2,300 cases and 1,670 deaths have been reported. These numbers pale in comparison with the burden caused by malnutrition or other infectious disease scourges in Africa such as malaria, cholera, AIDS, dengue or tuberculosis. However, due to their extremely high lethality, association with multifocal hemorrhaging and specificity to the African continent, these hemorrhagic fever viruses have given rise to great interest on the part not only of the international scientific community but also of the general public because of their perceived potential as biological weapons. Much research has been performed on these viruses and major progress has been made in knowledge of their ecology, epidemiology and physiopathology and in development of vaccine candidates and therapeutic schemes. The purpose of this review is to present the main developments in these particular fields in the last decade.
DEFF Research Database (Denmark)
Fabiansen, C.; Kronborg, G.; Thybo, S.
2008-01-01
This review presents the latest findings on ebola. Ebola presents one of the highest case-fatality rates of all infectious diseases, and in 2007 outbreaks were observed first in the Democratic Republic of Congo and later in Uganda with a new subtype. Accumulating evidence suggests that fruit bats...... are a likely reservoir for the ebola virus. The frequency of filovirus outbreaks in Central Africa is increasing and the potential for introduction and patient care in Denmark is evaluated Udgivelsesdato: 2008/11/24...
Directory of Open Access Journals (Sweden)
C.L. Carvalho
2017-03-01
Full Text Available Rabbit haemorrhagic disease virus 2 (RHDV2 emerged recently in several European countries, leading to extensive economic losses in the industry. In response to this new infection, specific inactivated vaccines were developed in Europe and full and rapid setup of protective immunity induced by vaccination was reported. However, data on the efficacy of these vaccines in an ongoing-infection scenario is unavailable. In this study we investigated an infected RHDV2 indoor industrial meat rabbitry, where fatalities continued to occur after the implementation of the RHDV2 vaccination, introduced to control the disease. The aim of this study was to understand if these mortalities were RHDV2-related, to discover if the dead animals showed any common features such as age or time distance from vaccination, and to identify the source of the outbreak. Anatomo-pathological analysis of vaccinated animals with the virus showed lesions compatible with systemic haemorrhagic disease and RHDV2-RNA was detected in 85.7% of the animals tested. Sequencing of the vp60 gene amplified from liver samples led to the recognition of RHDV2 field strains demonstrating that after the implementation of vaccination, RHDV2 continued to circulate in the premises and to cause sporadic deaths. A nearby, semi-intensive, RHDV2 infected farm belonging to the same owner was identified as the most probable source of the virus. The main risk factors for virus introduction in these two industries were identified. Despite the virus being able to infect a few of the vaccinated rabbits, the significant decrease in mortality rate observed in vaccinated adult rabbits clearly reflects the efficacy of the vaccination. Nonetheless, the time taken to control the infection also highlights the importance of RHDV2 vaccination prior to the first contact with the virus, highly recommendable in endemic areas, to mitigate the infection’s impact on the industry.
Single-particle cryo-electron microscopy of Rift Valley fever virus
Sherman, Michael B.; Freiberg, Alexander N.; Holbrook, Michael R.; Watowich, Stanley J.
2009-01-01
Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human veterinary pathogen causing acute hepatitis in ruminants and has the potential to Single-particle cryo-EM reconstruction of RVFV MP-12 hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on...
Single-particle cryo-electron microscopy of Rift Valley fever virus
International Nuclear Information System (INIS)
Sherman, Michael B.; Freiberg, Alexander N.; Holbrook, Michael R.; Watowich, Stanley J.
2009-01-01
Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human and veterinary pathogen causing acute hepatitis in ruminants and has the potential to cause hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on the virus surface are highly symmetric and arranged on a T = 12 icosahedral lattice. Our RVFV MP-12 structure allowed clear identification of inter-capsomer contacts and definition of possible glycoprotein arrangements within capsomers. This structure provides a detailed model for phleboviruses, opens new avenues for high-resolution structural studies of the bunyavirus family, and aids the design of antiviral diagnostics and effective subunit vaccines.
Single-particle cryo-electron microscopy of Rift Valley fever virus.
Sherman, Michael B; Freiberg, Alexander N; Holbrook, Michael R; Watowich, Stanley J
2009-04-25
Rift Valley fever virus (RVFV; Bunyaviridae; Phlebovirus) is an emerging human and veterinary pathogen causing acute hepatitis in ruminants and has the potential to cause hemorrhagic fever in humans. We report a three-dimensional reconstruction of RVFV vaccine strain MP-12 (RVFV MP-12) by cryo-electron microcopy using icosahedral symmetry of individual virions. Although the genomic core of RVFV MP-12 is apparently poorly ordered, the glycoproteins on the virus surface are highly symmetric and arranged on a T=12 icosahedral lattice. Our RVFV MP-12 structure allowed clear identification of inter-capsomer contacts and definition of possible glycoprotein arrangements within capsomers. This structure provides a detailed model for phleboviruses, opens new avenues for high-resolution structural studies of the bunyavirus family, and aids the design of antiviral diagnostics and effective subunit vaccines.
DETECTION OF CLASSICAL SWINE FEVER VIRUS BY RT-PCR IN WEST BENGAL, INDIA
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Sumit Chowdhury
2016-12-01
Full Text Available Classical swine fever is a deadly disease of swine, caused by a RNA virus. The present study has identified presence of the classical swine fever virus (CSFV in pigs of West Bengal by one step reverse transcriptase PCR (RT-PCR performed using 5’ NTR specific primers. Internal organs from clinically affected pigs were examined from three districts of West Bengal. RT-PCT has identified presence of CSFV in all the tissues examined confirming presence of CSFV in different parts of the state.
DEFF Research Database (Denmark)
Einer-Jensen, Katja; Winton, J.; Lorenzen, Niels
2005-01-01
The aim of this study was to develop a standardized molecular assay that used limited resources and equipment for routine genotyping of isolates of the fish rhabdovirus, viral haemorrhagic septicaemia virus (VHSV). Computer generated restriction maps, based on 62 unique full-length (1524 nt....... Experimental evaluation of the method consisted of three steps: (i) RT-PCR amplification of the G-gene of VHSV isolates using purified viral RNA as template, (ii) digestion of the PCR products with a panel of restriction endonucleases and (iii) interpretation of the resulting RFLP profiles. The RFLP analysis...
Gadia, Christelle Luce Bobossi; Manirakiza, Alexandre; Tekpa, Gaspard; Konamna, Xavier; Vickos, Ulrich; Nakoune, Emmanuel
2017-11-29
Febrile jaundice results clinically in generalized yellow coloration of the teguments and mucous membranes due to excess plasma bilirubin, accompanied by fever. Two types are found: conjugated and unconjugated bilirubin jaundice. Jaundice is a sign in several diseases due to viruses (viral hepatitis and arbovirus), parasites (malaria) and bacteria (leptospirosis). In the Central African Republic (CAR), only yellow fever is included on the list of diseases for surveillance. The aim of this study was to identify the other pathogens that can cause febrile jaundice, for better management of patients. Between 2008 and 2010, 198 sera negative for yellow fever IgM were randomly selected from 2177 samples collected during yellow fever surveillance. Laboratory analyses targeted four groups of pathogens: hepatitis B, C, delta and E viruses; dengue, chikungunya, Zika, Crimean-Congo haemorrhagic fever, West Nile and Rift Valley arboviruses; malaria parasites; and bacteria (leptospirosis). Overall, 30.9% sera were positive for hepatitis B, 20.2% for hepatitis E, 12.3% for hepatitis C and 8.2% for malaria. The majority of positive sera (40.4%) were from people aged 16-30 years. Co-infection with at least two of these pathogens was also found. These findings suggest that a systematic investigation should be undertaken of infectious agents that cause febrile jaundice in the CAR.
Directory of Open Access Journals (Sweden)
Beatriz Sierra
2017-02-01
Full Text Available Ethnic groups can display differential genetic susceptibility to infectious diseases. The arthropod-born viral dengue disease is one such disease, with empirical and limited genetic evidence showing that African ancestry may be protective against the haemorrhagic phenotype. Global ancestry analysis based on high-throughput genotyping in admixed populations can be used to test this hypothesis, while admixture mapping can map candidate protective genes. A Cuban dengue fever cohort was genotyped using a 2.5 million SNP chip. Global ancestry was ascertained through ADMIXTURE and used in a fine-matched corrected association study, while local ancestry was inferred by the RFMix algorithm. The expression of candidate genes was evaluated by RT-PCR in a Cuban dengue patient cohort and gene set enrichment analysis was performed in a Thai dengue transcriptome. OSBPL10 and RXRA candidate genes were identified, with most significant SNPs placed in inferred weak enhancers, promoters and lncRNAs. OSBPL10 had significantly lower expression in Africans than Europeans, while for RXRA several SNPs may differentially regulate its transcription between Africans and Europeans. Their expression was confirmed to change through dengue disease progression in Cuban patients and to vary with disease severity in a Thai transcriptome dataset. These genes interact in the LXR/RXR activation pathway that integrates lipid metabolism and immune functions, being a key player in dengue virus entrance into cells, its replication therein and in cytokine production. Knockdown of OSBPL10 expression in THP-1 cells by two shRNAs followed by DENV2 infection tests led to a significant reduction in DENV replication, being a direct functional proof that the lower OSBPL10 expression profile in Africans protects this ancestry against dengue disease.
Crimean-Congo Hemorrhagic Fever Virus in Bulgaria and Turkey
Czech Academy of Sciences Publication Activity Database
Mertens, M.; Schuster, I.; Sas, M. A.; Vatansever, Z.; Hubálek, Zdeněk; Güven, E.; Deniz, A.; Georgiev, G.; Peshev, R.; Groschup, M. H.
2016-01-01
Roč. 16, č. 9 (2016), s. 619-623 ISSN 1530-3667 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Crimean-Congo hemorrhagic fever virus: CCHFV * domestic animals * ELISA * epidemiology Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.045, year: 2016
Directory of Open Access Journals (Sweden)
Sanchita Das
Full Text Available CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR. The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively. The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus.
Das, Sanchita; Rundell, Mark S; Mirza, Aashiq H; Pingle, Maneesh R; Shigyo, Kristi; Garrison, Aura R; Paragas, Jason; Smith, Scott K; Olson, Victoria A; Larone, Davise H; Spitzer, Eric D; Barany, Francis; Golightly, Linnie M
2015-01-01
CDC designated category A infectious agents pose a major risk to national security and require special action for public health preparedness. They include viruses that cause viral hemorrhagic fever (VHF) syndrome as well as variola virus, the agent of smallpox. VHF is characterized by hemorrhage and fever with multi-organ failure leading to high morbidity and mortality. Smallpox, a prior scourge, has been eradicated for decades, making it a particularly serious threat if released nefariously in the essentially non-immune world population. Early detection of the causative agents, and the ability to distinguish them from other pathogens, is essential to contain outbreaks, implement proper control measures, and prevent morbidity and mortality. We have developed a multiplex detection assay that uses several species-specific PCR primers to generate amplicons from multiple pathogens; these are then targeted in a ligase detection reaction (LDR). The resultant fluorescently-labeled ligation products are detected on a universal array enabling simultaneous identification of the pathogens. The assay was evaluated on 32 different isolates associated with VHF (ebolavirus, marburgvirus, Crimean Congo hemorrhagic fever virus, Lassa fever virus, Rift Valley fever virus, Dengue virus, and Yellow fever virus) as well as variola virus and vaccinia virus (the agent of smallpox and its vaccine strain, respectively). The assay was able to detect all viruses tested, including 8 sequences representative of different variola virus strains from the CDC repository. It does not cross react with other emerging zoonoses such as monkeypox virus or cowpox virus, or six flaviviruses tested (St. Louis encephalitis virus, Murray Valley encephalitis virus, Powassan virus, Tick-borne encephalitis virus, West Nile virus and Japanese encephalitis virus).
Modulation of Translation Initiation Efficiency in Classical Swine Fever Virus
DEFF Research Database (Denmark)
Friis, Martin Barfred; Rasmussen, Thomas Bruun; Belsham, Graham
2012-01-01
Modulation of translation initiation efficiency on classical swine fever virus (CSFV) RNA can be achieved by targeted mutations within the internal ribosome entry site (IRES). In this study, cDNAs corresponding to the wild type (wt) or mutant forms of the IRES of CSFV strain Paderborn were...... in vitro and electroporated into porcine PK15 cells. Rescued mutant viruses were obtained from RNAs that contained mutations within domain IIIf which retained more than 75% of wt translation efficiency. Sequencing of cDNA generated from these rescued viruses verified the maintenance of the introduced...... changes within the IRES. The growth characteristics of each rescued mutant virus were compared to that of the wt virus. It was shown that viable mutant viruses with reduced translation initiation efficiency can be designed and generated and that viruses containing mutations within domain IIIf of the IRES...
C.L. Carvalho; E.L. Duarte; J.M. Monteiro; C. Afonso; J. Pacheco; P. Carvalho; P. Mendonça; A. Botelho; T. Albuquerque; P. Themudo; M. Fevereiro; A.M. Henriques; S.S. Santos Barros; M. Dias Duarte
2017-01-01
Rabbit haemorrhagic disease virus 2 (RHDV2) emerged recently in several European countries, leading to extensive economic losses in the industry. In response to this new infection, specific inactivated vaccines were developed in Europe and full and rapid setup of protective immunity induced by vaccination was reported. However, data on the efficacy of these vaccines in an ongoing-infection scenario is unavailable. In this study we investigated an infected RHDV2 indoor industrial meat rabbitry...
THROMBOCYTOPENIA IN DENGUE HAEMORRHAGIC FEVER
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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.
Comparison of sampling techniques for Rift Valley Fever virus ...
African Journals Online (AJOL)
We investigated mosquito sampling techniques with two types of traps and attractants at different time for trapping potential vectors for Rift Valley Fever virus. The study was conducted in six villages in Ngorongoro district in Tanzania from September to October 2012. A total of 1814 mosquitoes were collected, of which 738 ...
DEFF Research Database (Denmark)
Utke, K.; Bergmann, S.; Lorenzen, Niels
2007-01-01
classical MHC class I locus Onmy-UBA is identical in the rainbow trout clone C25 and in the permanent rainbow trout cell line RTG-2. This enabled us to develop an assay to measure antiviral cytotoxicity in rainbow trout using a system of MHC class I-matched effector and target cells. Peripheral blood...... leucocytes (PBL) isolated from low dose viral haemorrhagic septicaemia virus (VHSV)-infected rainbow trout killed MHC class I-matched and later also xenogeneic MHC class I-mismatched VHSV-infected cells. When compared to PBL from uninfected control fish PBL from infected fish showed a higher transcriptional...
El Mekki, A A; van der Groen, G
1981-09-01
Yellow fever, dengue (types 1, 2 and 4), Chikungunya, Rift Valley fever, Ebola, Marburg, and Lassa viruses were inoculated into susceptible cell cultures and daily investigated by indirect immunofluorescence (IFA) and electron microscopy (EM) with a view to achieve an early detection-identification of these agents. Compared to the other cell lines tested (Vero, BHK-21 and Aedes albopictus), CV-1 cells were found to be more sensitive. Viral antigens were detected by IFA from a few hours post inoculation (CHIK and RVF) to a maximum of 3 days (YF and EBO). For most of the viruses studied, the cytopathic effect (CPE) commenced 2-3 days after the detection of viral antigens. Virus particles were detected by EM only in the case of EBO, MBG and LAS, before any CPE was observed in cell cultures.
Lineage-Specific Real-Time RT-PCR for Yellow Fever Virus Outbreak Surveillance, Brazil.
Fischer, Carlo; Torres, Maria C; Patel, Pranav; Moreira-Soto, Andres; Gould, Ernest A; Charrel, Rémi N; de Lamballerie, Xavier; Nogueira, Rita Maria Ribeiro; Sequeira, Patricia C; Rodrigues, Cintia D S; Kümmerer, Beate M; Drosten, Christian; Landt, Olfert; Bispo de Filippis, Ana Maria; Drexler, Jan Felix
2017-11-01
The current yellow fever outbreak in Brazil prompted widespread yellow fever virus (YFV) vaccination campaigns, imposing a responsibility to distinguish between vaccine- and wild-type YFV-associated disease. We developed novel multiplex real-time reverse transcription PCRs that differentiate between vaccine and American wild-type YFV. We validated these highly specific and sensitive assays in an outbreak setting.
Lineage-Specific Real-Time RT-PCR for Yellow Fever Virus Outbreak Surveillance, Brazil
Fischer, Carlo; Torres, Maria C.; Patel, Pranav; Moreira-Soto, Andres; Gould, Ernest A.; Charrel, Rémi N.; de Lamballerie, Xavier; Nogueira, Rita Maria Ribeiro; Sequeira, Patricia C.; Rodrigues, Cintia D.S.; Kümmerer, Beate M.; Drosten, Christian; Landt, Olfert; Bispo de Filippis, Ana Maria; Drexler, Jan Felix
2017-01-01
The current yellow fever outbreak in Brazil prompted widespread yellow fever virus (YFV) vaccination campaigns, imposing a responsibility to distinguish between vaccine- and wild-type YFV-associated disease. We developed novel multiplex real-time reverse transcription PCRs that differentiate between vaccine and American wild-type YFV. We validated these highly specific and sensitive assays in an outbreak setting.
Investigations into yellow fever virus and other arboviruses in the northern regions of Kenya.
Henderson, B E; Metselaar, D; Kirya, G B; Timms, G L
1970-01-01
Previous studies having shown an appreciable level of yellow fever immunity to exist in northern Kenya, further epidemiological and serological surveys were carried out there in 1968 in an attempt to define more clearly the distribution of yellow fever and to locate possible vector and reservoir hosts of the disease; these surveys also provided information on a number of other arboviruses.Altogether 436 sera from 5 areas in northern Kenya were screened by haemagglutination-inhibition tests with 8 antigens, and 107 of these sera by neutralization tests for Group-B arboviruses. Small numbers of yellow-fever-immune adults were found in Ileret, Garissa, Loglogo and Mikona. At Marsabit high proportions of immune adults and children were found among the Burgi tribe. As the Burgi are permanent agricultural workers on Marsabit Mountain, an entomological investigation was made, over 15 000 mosquitos being collected. From these, 13 strains of Pongola virus, 1 strain of Semliki Forest virus and an unidentified virus were isolated, but no yellow fever strains. Aedes africanus and Aedes simpsoni were not found at Marsabit; small numbers of Aedes aegypti were collected biting man. The vector potential of other mosquitos collected (particularly Mansonia africana, which is present throughout the year) is discussed.
An Outbreak of Ebola Virus Disease in the Lassa Fever Zone.
Goba, Augustine; Khan, S Humarr; Fonnie, Mbalu; Fullah, Mohamed; Moigboi, Alex; Kovoma, Alice; Sinnah, Vandi; Yoko, Nancy; Rogers, Hawa; Safai, Siddiki; Momoh, Mambu; Koroma, Veronica; Kamara, Fatima K; Konowu, Edwin; Yillah, Mohamed; French, Issa; Mustapha, Ibraham; Kanneh, Franklyn; Foday, Momoh; McCarthy, Helena; Kallon, Tiangay; Kallon, Mustupha; Naiebu, Jenneh; Sellu, Josephine; Jalloh, Abdul A; Gbakie, Michael; Kanneh, Lansana; Massaly, James L B; Kargbo, David; Kargbo, Brima; Vandi, Mohamed; Gbetuwa, Momoh; Gevao, Sahr M; Sandi, John D; Jalloh, Simbirie C; Grant, Donald S; Blyden, Sylvia O; Crozier, Ian; Schieffelin, John S; McLellan, Susan L; Jacob, Shevin T; Boisen, Matt L; Hartnett, Jessica N; Cross, Robert W; Branco, Luis M; Andersen, Kristian G; Yozwiak, Nathan L; Gire, Stephen K; Tariyal, Ridhi; Park, Daniel J; Haislip, Allyson M; Bishop, Christopher M; Melnik, Lilia I; Gallaher, William R; Wimley, William C; He, Jing; Shaffer, Jeffrey G; Sullivan, Brian M; Grillo, Sonia; Oman, Scott; Garry, Courtney E; Edwards, Donna R; McCormick, Stephanie J; Elliott, Deborah H; Rouelle, Julie A; Kannadka, Chandrika B; Reyna, Ashley A; Bradley, Benjamin T; Yu, Haini; Yenni, Rachael E; Hastie, Kathryn M; Geisbert, Joan B; Kulakosky, Peter C; Wilson, Russell B; Oldstone, Michael B A; Pitts, Kelly R; Henderson, Lee A; Robinson, James E; Geisbert, Thomas W; Saphire, Erica Ollmann; Happi, Christian T; Asogun, Danny A; Sabeti, Pardis C; Garry, Robert F
2016-10-15
Kenema Government Hospital (KGH) has developed an advanced clinical and laboratory research capacity to manage the threat of Lassa fever, a viral hemorrhagic fever (VHF). The 2013-2016 Ebola virus (EBOV) disease (EVD) outbreak is the first to have occurred in an area close to a facility with established clinical and laboratory capacity for study of VHFs. Because of its proximity to the epicenter of the EVD outbreak, which began in Guinea in March 2014, the KGH Lassa fever Team mobilized to establish EBOV surveillance and diagnostic capabilities. Augustine Goba, director of the KGH Lassa laboratory, diagnosed the first documented case of EVD in Sierra Leone, on 25 May 2014. Thereafter, KGH received and cared for numbers of patients with EVD that quickly overwhelmed the capacity for safe management. Numerous healthcare workers contracted and lost their lives to EVD. The vast majority of subsequent EVD cases in West Africa can be traced back to a single transmission chain that includes this first diagnosed case. Responding to the challenges of confronting 2 hemorrhagic fever viruses will require continued investments in the development of countermeasures (vaccines, therapeutic agents, and diagnostic assays), infrastructure, and human resources. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.
Camarda, A; Pugliese, N; Cavadini, P; Circella, E; Capucci, L; Caroli, A; Legretto, M; Mallia, E; Lavazza, A
2014-12-01
Rabbit haemorrhagic disease virus (RHDV), a member of the genus Lagovirus, causes rabbit haemorrhagic disease (RHD), a fatal hepatitis of rabbits, not previously reported in hares. Recently, a new RHDV-related virus emerged, called RHDV2. This lagovirus can cause RHD in rabbits and disease and mortality in Lepus capensis (Cape hare). Here we describe a case of RHDV2 infection in another hare species, Lepus corsicanus, during a concurrent RHD outbreak in a group of wild rabbits. The same RHDV2 strain infected rabbits and a hare, also causing a RHD-like syndrome in the latter. Our findings confirmed the capability of RHDV2 to infect hosts other than rabbits and improve the knowledge about the epidemiology and the host range of this new lagovirus. Copyright © 2014 Elsevier Ltd. All rights reserved.
Serological reactions in Rhesus monkeys inoculated with the 17D strain of yellow fever virus.
GROOT, H
1962-01-01
Haemagglutination-inhibition tests, which depend on the appearance of haemagglutination-inhibiting antibodies in the serum in virus infections, are in common use in the study of arthropod-borne diseases. This paper contains the results of an investigation into the appearance and pattern of haemagglutination-inhibiting antibodies in the serum of rhesus monkeys inoculated intracerebrally with the 17D strain of yellow fever virus during the testing of seed lots of yellow fever vaccine. These antibodies appeared on the tenth day after inoculation, and were still demonstrable four years later. In all of the eight monkeys tested complement-fixing and neutralizing antibodies against yellow fever antigens also developed, and in six out of the eight heterologous antigens developed.
Efficient cellular release of Rift Valley fever virus requires genomic RNA.
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Mary E Piper
2011-03-01
Full Text Available The Rift Valley fever virus is responsible for periodic, explosive epizootics throughout sub-Saharan Africa. The development of therapeutics targeting this virus is difficult due to a limited understanding of the viral replicative cycle. Utilizing a virus-like particle system, we have established roles for each of the viral structural components in assembly, release, and virus infectivity. The envelope glycoprotein, Gn, was discovered to be necessary and sufficient for packaging of the genome, nucleocapsid protein and the RNA-dependent RNA polymerase into virus particles. Additionally, packaging of the genome was found to be necessary for the efficient release of particles, revealing a novel mechanism for the efficient generation of infectious virus. Our results identify possible conserved targets for development of anti-phlebovirus therapies.
Acid-activated structural reorganization of the Rift Valley fever virus Gc fusion protein
Boer, de S.M.; Kortekaas, J.A.; Spel, L.; Rottier, P.J.M.; Moormann, R.J.M.; Bosch, B.J.
2012-01-01
Entry of the enveloped Rift Valley fever virus (RVFV) into its host cell is mediated by the viral glycoproteins Gn and Gc. We investigated the RVFV entry process and its pH-dependent activation mechanism in particular using our recently developed nonspreading RVFV particle system. Entry of the virus
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Séverine Mercier-Delarue
Full Text Available Given the possibility of yellow fever virus reintroduction in epidemiologically receptive geographic areas, the risk of vaccine supply disruption is a serious issue. New strategies to reduce the doses of injected vaccines should be evaluated very carefully in terms of immunogenicity. The plaque reduction test for the determination of neutralizing antibodies (PRNT is particularly time-consuming and requires the use of a confinement laboratory. We have developed a new test based on the use of a non-infectious pseudovirus (WN/YF17D. The presence of a reporter gene allows sensitive determination of neutralizing antibodies by flow cytometry. This WN/YF17D test was as sensitive as PRNT for the follow-up of yellow fever vaccinees. Both tests lacked specificity with sera from patients hospitalized for acute Dengue virus infection. Conversely, both assays were strictly negative in adults never exposed to flavivirus infection or vaccination, and in patients sampled some time after acute Dengue infection. This WN/YF17D test will be particularly useful for large epidemiological studies and for screening for neutralizing antibodies against yellow fever virus.
Nishiyama, Shoko; Slack, Olga A L; Lokugamage, Nandadeva; Hill, Terence E; Juelich, Terry L; Zhang, Lihong; Smith, Jennifer K; Perez, David; Gong, Bin; Freiberg, Alexander N; Ikegami, Tetsuro
2016-11-16
Rift Valley fever is a mosquito-borne zoonotic disease affecting ruminants and humans. Rift Valley fever virus (RVFV: family Bunyaviridae, genus Phlebovirus) causes abortions and fetal malformations in ruminants, and hemorrhagic fever, encephalitis, or retinitis in humans. The live-attenuated MP-12 vaccine is conditionally licensed for veterinary use in the US. However, this vaccine lacks a marker for the differentiation of vaccinated from infected animals (DIVA). NSs gene is dispensable for RVFV replication, and thus, rMP-12 strains lacking NSs gene is applicable to monitor vaccinated animals. However, the immunogenicity of MP-12 lacking NSs was not as high as parental MP-12. Thus, chimeric MP-12 strains encoding NSs from either Toscana virus (TOSV), sandfly fever Sicilian virus (SFSV) or Punta Toro virus Adames strain (PTA) were characterized previously. Although chimeric MP-12 strains are highly immunogenic, the attenuation through the S-segment remains unknown. Using pathogenic ZH501 strain, we aimed to demonstrate the attenuation of ZH501 strain through chimeric S-segment encoding either the NSs of TOSV, SFSV, PTA, or Punta Toro virus Balliet strain (PTB). In addition, we characterized rZH501 encoding a human dominant-negative PKR (PKRΔE7), which also enhances the immunogenicity of MP-12. Study done on mice revealed that attenuation of rZH501 occurred through the S-segment encoding either PKRΔE7 or SFSV NSs. However, rZH501 encoding either TOSV, PTA, or PTB NSs in the S-segment uniformly caused lethal encephalitis. Our results indicated that the S-segments encoding PKRΔE7 or SFSV NSs are attenuated and thus applicable toward next generation MP-12 vaccine candidates that encode a DIVA marker.
A flow cytometry-based assay for quantifying non-plaque forming strains of yellow fever virus.
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Erika Hammarlund
Full Text Available Primary clinical isolates of yellow fever virus can be difficult to quantitate by standard in vitro methods because they may not form discernable plaques or induce a measurable cytopathic effect (CPE on cell monolayers. In our hands, the Dakar strain of yellow fever virus (YFV-Dakar could not be measured by plaque assay (PA, focus-forming assay (FFA, or by measurement of CPE. For these reasons, we developed a YFV-specific monoclonal antibody (3A8.B6 and used it to optimize a highly sensitive flow cytometry-based tissue culture limiting dilution assay (TC-LDA to measure levels of infectious virus. The TC-LDA was performed by incubating serial dilutions of virus in replicate wells of C6/36 cells and stained intracellularly for virus with MAb 3A8.B6. Using this approach, we could reproducibly quantitate YFV-Dakar in tissue culture supernatants as well as from the serum of viremic rhesus macaques experimentally infected with YFV-Dakar. Moreover, the TC-LDA approach was >10-fold more sensitive than standard plaque assay for quantitating typical plaque-forming strains of YFV including YFV-17D and YFV-FNV (French neurotropic vaccine. Together, these results indicate that the TC-LDA technique is effective for quantitating both plaque-forming and non-plaque-forming strains of yellow fever virus, and this methodology may be readily adapted for the study and quantitation of other non-plaque-forming viruses.
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Shoko eNishiyama
2015-08-01
Full Text Available Rift Valley fever (RVF is a mosquito-borne zoonotic disease endemic to the African continent. RVF is characterized by high rate of abortions in ruminants and hemorrhagic fever, encephalitis or blindness in humans. RVF is caused by the Rift Valley fever virus (RVFV: genus Phlebovirus, family Bunyaviridae. Vaccination is the only known effective strategy to prevent the disease, but there are no licensed RVF vaccines available for humans. A live-attenuated vaccine candidate derived from the wild-type pathogenic Egyptian ZH548 strain, MP-12, has been conditionally licensed for veterinary use in the United States. MP-12 displays a temperature-sensitive (ts phenotype and does not replicate at 41oC. The ts mutation limits viral replication at a specific body temperature and may lead to an attenuation of the virus. Here we will review well-characterized ts mutations for RNA viruses, and further discuss the potential in designing novel live-attenuated vaccines for RVF.
Velarde, R.; Cavadini, P.; Neimanis, A.; Cabezón, O.; Chiari, M.; Gaffuri, A.; Lavín, S.; Grilli, G.; Gavier‐Widén, D.; Lavazza, A.; Capucci, L.
2016-01-01
Summary Rabbit haemorrhagic disease virus (RHDV) is a lagovirus that can cause fatal hepatitis (rabbit haemorrhagic disease, RHD) with mortality of 80–90% in farmed and wild rabbits. Since 1986, RHDV has caused outbreaks in rabbits (Oryctolagus cuniculus) in Europe, but never in European brown hares (Lepus europaeus, EBH). In 2010, a new RHDV‐related virus, called RHDV2, emerged in Europe, causing extended epidemics because it largely overcame the immunity to RHDV present in most rabbit popul...
van der Waals, F. W.; Pomeroy, K. L.; Goudsmit, J.; Asher, D. M.; Gajdusek, D. C.
1986-01-01
Serum samples from 119 healthy individuals and 106 epilepsy patients inhabiting Grand Bassa County, Liberia, were tested for antibodies to hemorrhagic fever viruses (HFV) by indirect immunofluorescence. E6 Vero cells infected with Lassa fever virus (LAS), Rift Valley Fever virus (RVF), Congo
Reported 5 cases of Crimean-Congo hemorrhagic fever in Fars province in 2011
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Fatemeh Rezaei
2012-09-01
Full Text Available Crimean-Congo Hemorrhagic Fever (CCHF is a viral hemorrhagic disease and a zoonosis disease that has been developed in people who deal with animals such as cattle and butchers. The diagnosis of CCHF is performed by detection of human antibodies (IgG and IgM against CCHF virus. Five Patients with CCHF occurred in Fath Abad’s village (in Fars province in the summer of 2011. All patients were men and aged 25-46 years old. Three patients were farmer and two other ones were butchers. The samples were sent to the National Reference Laboratory for Arboviruses and Viral Haemorrhagic Fevers (Pasteur Institute of Iran in Tehran. The result of laboratory test for all patients was positive. None of the patients had died. Since the CCHF is rare, present study was aimed to assess the causes of the disease’s epidemic and clinical and laboratory symptoms stones.
DEFF Research Database (Denmark)
Skall, Helle Frank; Slierendrecht, W.J.; King, J.A.
2004-01-01
The susceptibility of rainbow trout Oncorhynchus mykiss to infection with various isolates of viral haemorrhagic septicaemia virus (VHSV) was examined. A total of 8 experiments with rainbow trout ranging from 0.6 to 6.2 g was conducted for 139 isolates originating from wild marine fishes in Europ......The susceptibility of rainbow trout Oncorhynchus mykiss to infection with various isolates of viral haemorrhagic septicaemia virus (VHSV) was examined. A total of 8 experiments with rainbow trout ranging from 0.6 to 6.2 g was conducted for 139 isolates originating from wild marine fishes...... in European waters (115 isolates), farmed turbot from Scotland and Ireland (2 isolates), and farmed rainbow trout (22 isolates). The isolates were tested by immersion and/or intraperitoneal injection either as pooled or single isolates. The isolates from wild marine fishes did not cause mortality by immersion...... while some of the isolates caused mortality when injected. All VHSV isolates from farmed rainbow trout caused significant mortality by immersion. Currently, pathogenicity trials are the only way to differentiate VHSV isolates from wild marine fishes and farmed rainbow trout. The 2 farmed turbot isolates...
Dengue fever, or West Nile fever, is a mild viral illness transmitted by mosquitoes which causes fever, ... second exposure to the virus can result in Dengue hemorrhagic fever, a life-threatening illness.
Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes
Vloet, Rianka P.M.; Vogels, Chantal B.F.; Koenraadt, Constantianus J.M.; Pijlman, Gorben P.; Eiden, Martin; Gonzales, Jose L.; Keulen, van Lucien J.M.; Wichgers Schreur, Paul J.; Kortekaas, Jeroen
2017-01-01
Background: Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus
What Does the Future Hold for Yellow Fever Virus? (I
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Raphaëlle Klitting
2018-06-01
Full Text Available The recent resurgence of yellow fever virus (YFV activity in the tropical regions of Africa and South America has sparked renewed interest in this infamous arboviral disease. Yellow fever virus had been a human plague for centuries prior to the identification of its urban transmission vector, the Aedes (Stegomyia aegypti (Linnaeus mosquito species, and the development of an efficient live-attenuated vaccine, the YF-17D strain. The combination of vector-control measures and vaccination campaigns drastically reduced YFV incidence in humans on many occasions, but the virus never ceased to circulate in the forest, through its sylvatic invertebrate vector(s and vertebrate host(s. Outbreaks recently reported in Central Africa (2015–2016 and Brazil (since late 2016, reached considerable proportions in terms of spatial distribution and total numbers of cases, with multiple exports, including to China. In turn, questions about the likeliness of occurrence of large urban YFV outbreaks in the Americas or of a successful import of YFV to Asia are currently resurfacing. This two-part review describes the current state of knowledge and gaps regarding the molecular biology and transmission dynamics of YFV, along with an overview of the tools that can be used to manage the disease at individual, local and global levels.
Simultaneous circulation of genotypes I and III of dengue virus 3 in Colombia
Usme-Ciro, Jose A; Mendez, Jairo A; Tenorio, Antonio; Rey, Gloria J; Domingo, Cristina; Gallego-Gomez, Juan C
2008-01-01
Abstract Background Dengue is a major health problem in tropical and subtropical regions. In Colombia, dengue viruses (DENV) cause about 50,000 cases annually, 10% of which involve Dengue Haemorrhagic Fever/Dengue Shock Syndrome. The picture is similar in other surrounding countries in the Americas, with recent outbreaks of severe disease, mostly associated with DENV serotype 3, strains of the Indian genotype, introduced into the Americas in 1994. Results The analysis of the 3'end (224 bp) of...
Immunofluorescence Plaque Assay for African Swine Fever Virus
Tessler, J.; Hess, W. R.; Pan, I. C.; Trautman, R.
1974-01-01
Suitably diluted cell culture adapted African swine fever virus preparations were inoculated on VERO cell monolayers and grown on coverslips. Gum tragacanth was used as an overlay. After three days incubation at 37°C the infected cultures were fixed with acetone and stained with fluorescent antibody conjugate. Fluorescing plaques consisted of 20-30 infected cells. Three statistical criteria for a quantitatively reliable assay were met: the Poisson distribution for plaque counts, linearity of the relationship between the concentration of virus and the plaque count and reproducibility of replicate titrations. The method is suitable for counts up to at least 70 plaques per 5 cm2 coverslip and computed titers are reproducible within 0.16 log units with a total of 300 plaques enumerated. PMID:4279763
Dengue Haemorrhagic Encephalitis: Rare Case Report with Review of Literature.
Kutiyal, Aditya Singh; Malik, Chetanya; Hyanki, Gitika
2017-07-01
Dengue is an endemic arboviral infection prevalent especially in tropical countries including Southern and Southeast Asia. Central Nervous System (CNS) involvement in dengue infection is uncommon. Haemorrhagic encephalitis is a rare presentation in dengue. This is a case of a 58-year-old male who presented with fever, petechial rash and altered sensorium. Dengue serology IgM was reactive and MRI brain was suggestive of haemorrhagic encephalitis. Patient was managed in Intensive Care Unit (ICU) but eventually succumbed to his illness. We report this fatal outcome of a common viral infection with unusual neurological presentation to propose an association between dengue and neurotropism and the need to look at dengue infection beyond its classical features.
Mubemba, B; Thompson, P N; Odendaal, L; Coetzee, P; Venter, E H
2017-05-01
Rift Valley fever (RVF), caused by an arthropod borne Phlebovirus in the family Bunyaviridae, is a haemorrhagic disease that affects ruminants and humans. Due to the zoonotic nature of the virus, a biosafety level 3 laboratory is required for isolation of the virus. Fresh and frozen samples are the preferred sample type for isolation and acquisition of sequence data. However, these samples are scarce in addition to posing a health risk to laboratory personnel. Archived formalin-fixed, paraffin-embedded (FFPE) tissue samples are safe and readily available, however FFPE derived RNA is in most cases degraded and cross-linked in peptide bonds and it is unknown whether the sample type would be suitable as reference material for retrospective phylogenetic studies. A RT-PCR assay targeting a 490 nt portion of the structural G N glycoprotein encoding gene of the RVFV M-segment was applied to total RNA extracted from archived RVFV positive FFPE samples. Several attempts to obtain target amplicons were unsuccessful. FFPE samples were then analysed using next generation sequencing (NGS), i.e. Truseq ® (Illumina) and sequenced on the Miseq ® genome analyser (Illumina). Using reference mapping, gapped virus sequence data of varying degrees of shallow depth was aligned to a reference sequence. However, the NGS did not yield long enough contigs that consistently covered the same genome regions in all samples to allow phylogenetic analysis. Copyright © 2017 Elsevier B.V. All rights reserved.
Vertical transmission of Rift Valley Fever Virus without detectable maternal viremia
Antonis, A.F.G.; Kortekaas, J.A.; Kant-Eenbergen, H.C.M.; Vloet, R.P.M.; Vogel-Brink, A.; Stockhofe, N.; Moormann, R.J.M.
2013-01-01
Rift Valley fever virus (RVFV) is a zoonotic bunyavirus that causes abortions in domesticated ruminants. Sheep breeds exotic to endemic areas are reportedly the most susceptible to RVFV infection. Within the scope of a risk assessment program of The Netherlands, we investigated the susceptibility of
Molecular Insights into Crimean-Congo Hemorrhagic Fever Virus
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Marko Zivcec
2016-04-01
Full Text Available Crimean-Congo hemorrhagic fever virus (CCHFV is a tick-borne pathogen that causes high morbidity and mortality. Efficacy of vaccines and antivirals to treat human CCHFV infections remains limited and controversial. Research into pathology and underlying molecular mechanisms of CCHFV and other nairoviruses is limited. Significant progress has been made in our understanding of CCHFV replication and pathogenesis in the past decade. Here we review the most recent molecular advances in CCHFV-related research, and provide perspectives on future research.
Acute haemorrhagic oedema of infancy with bullae and koebnerisation
Mohd Sazlly Lim, S; Shamsudin, N
2014-01-01
A 5-month-old Malay boy presented with purpuric papules and plaques on the face and extremities accompanied by fever, coryzal symptoms and bilateral lower limb oedema. There were also bullous linear purpuric lesions on the right upper limb. Blood and culture tests were normal. Histopathological tests showed leucocytoclastic vasculitis, confirming the diagnosis of acute haemorrhagic oedema of infancy. The patient achieved complete recovery after 2 weeks with no recurrence.
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Nanikaly Moyen
Full Text Available Ebola and Marburg viruses (family Filoviridae, genera Ebolavirus and Marburgvirus cause haemorrhagic fevers in humans, often associated with high mortality rates. The presence of antibodies to Ebola virus (EBOV and Marburg virus (MARV has been reported in some African countries in individuals without a history of haemorrhagic fever. In this study, we present a MARV and EBOV seroprevalence study conducted amongst blood donors in the Republic of Congo and the analysis of risk factors for contact with EBOV.In 2011, we conducted a MARV and EBOV seroprevalence study amongst 809 blood donors recruited in rural (75; 9.3% and urban (734; 90.7% areas of the Republic of Congo. Serum titres of IgG antibodies to MARV and EBOV were assessed by indirect double-immunofluorescence microscopy. MARV seroprevalence was 0.5% (4 in 809 without any identified risk factors. Prevalence of IgG to EBOV was 2.5%, peaking at 4% in rural areas and in Pointe Noire. Independent risk factors identified by multivariate analysis were contact with bats and exposure to birds.This MARV and EBOV serological survey performed in the Republic of Congo identifies a probable role for environmental determinants of exposure to EBOV. It highlights the requirement for extending our understanding of the ecological and epidemiological risk of bats (previously identified as a potential ecological reservoir and birds as vectors of EBOV to humans, and characterising the protection potentially afforded by EBOV-specific antibodies as detected in blood donors.
A fusion-inhibiting peptide against Rift Valley fever virus inhibits multiple, diverse viruses.
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Jeffrey W Koehler
Full Text Available For enveloped viruses, fusion of the viral envelope with a cellular membrane is critical for a productive infection to occur. This fusion process is mediated by at least three classes of fusion proteins (Class I, II, and III based on the protein sequence and structure. For Rift Valley fever virus (RVFV, the glycoprotein Gc (Class II fusion protein mediates this fusion event following entry into the endocytic pathway, allowing the viral genome access to the cell cytoplasm. Here, we show that peptides analogous to the RVFV Gc stem region inhibited RVFV infectivity in cell culture by inhibiting the fusion process. Further, we show that infectivity can be inhibited for diverse, unrelated RNA viruses that have Class I (Ebola virus, Class II (Andes virus, or Class III (vesicular stomatitis virus fusion proteins using this single peptide. Our findings are consistent with an inhibition mechanism similar to that proposed for stem peptide fusion inhibitors of dengue virus in which the RVFV inhibitory peptide first binds to both the virion and cell membranes, allowing it to traffic with the virus into the endocytic pathway. Upon acidification and rearrangement of Gc, the peptide is then able to specifically bind to Gc and prevent fusion of the viral and endocytic membranes, thus inhibiting viral infection. These results could provide novel insights into conserved features among the three classes of viral fusion proteins and offer direction for the future development of broadly active fusion inhibitors.
Borca, Manuel V; Holinka, Lauren G; Berggren, Keith A; Gladue, Douglas P
2018-02-16
African swine fever virus (ASFV) causes a highly contagious disease called African swine fever. This disease is often lethal for domestic pigs, causing extensive losses for the swine industry. ASFV is a large and complex double stranded DNA virus. Currently there is no commercially available treatment or vaccine to prevent this devastating disease. Development of recombinant ASFV for producing live-attenuated vaccines or studying the involvement of specific genes in virus virulence has relied on the relatively rare event of homologous recombination in primary swine macrophages, causing difficulty to purify the recombinant virus from the wild-type parental ASFV. Here we present the use of the CRISPR-Cas9 gene editing system as a more robust and efficient system to produce recombinant ASFVs. Using CRISPR-Cas9 a recombinant virus was efficiently developed by deleting the non-essential gene 8-DR from the genome of the highly virulent field strain Georgia07 using swine macrophages as cell substrate.
International Nuclear Information System (INIS)
Nazly Hilmy; Paramita Pandansari
2008-01-01
Full text: New emerging and re- emerging infectious diseases caused by viruses are outbreak and re- outbreak around the world. Most of the viruses come from animals ( zoonoses) and jump to human beings ( host jumping ) such as corona virus ( SARS), HIV, bird flu/ Avian flu H5N1, hepatitis viruses, Dengue fever virus, West Nile virus/WNV, Hantavirus, Marburg haemorrhagic fever virus, Hendra virus, Nipah virus etc. Transmission of those diseases through transplantation of contaminated tissue allograft to recipient can happened if the donor could not be screened properly. The donor can be well screened from some of those viruses such as HIV, hepatitis viruses and WNV. Processing of tissue allografts by pasteurization, washing and soaking in H 2 O 2 and soap can eliminate contaminated viruses to a certain amount, have been reported by several authors. Viruses are very small microbes, they have DNA/RNA, resistant to radiation but to a certain degree they can be well eliminated by radiation. Their D10 - values vary from 4 to 13 kGy. This paper discribes briefly the possibility of using combined treatment of processing, lyophilization and sterilisation by radiation to overcome problems of non screened donor from some contaminated viruses. (Author)
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Fonnie Mbalu
2011-06-01
Full Text Available Abstract Lassa fever is a neglected tropical disease with a significant impact on the health care system of endemic West African nations. To date, case reports of Lassa fever have focused on laboratory characterisation of serological, biochemical and molecular aspects of the disease imported by infected individuals from Western Africa to the United States, Canada, Europe, Japan and Israel. Our report presents the first comprehensive real time diagnosis and characterization of a severe, hemorrhagic Lassa fever case in a Sierra Leonean individual admitted to the Kenema Government Hospital Lassa Fever Ward. Fever, malaise, unresponsiveness to anti-malarial and antibiotic drugs, followed by worsening symptoms and onset of haemorrhaging prompted medical officials to suspect Lassa fever. A recombinant Lassa virus protein based diagnostic was employed in diagnosing Lassa fever upon admission. This patient experienced a severe case of Lassa hemorrhagic fever with dysregulation of overall homeostasis, significant liver and renal system involvement, the interplay of pro- and anti-inflammatory cytokines during the course of hospitalization and an eventual successful outcome. These studies provide new insights into the pathophysiology and management of this viral illness and outline the improved infrastructure, research and real-time diagnostic capabilities within LASV endemic areas.
Acute haemorrhagic oedema of infancy with bullae and koebnerisation
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Norashikin Shamsudin
2014-08-01
Full Text Available A 5-month-old Malay boy presented with purpuric papules and plaques on the face and extremities accompanied by fever, coryzal symptoms and bilateral lower limb oedema. There were also bullous linear purpuric lesions on the right upper limb. Blood and culture tests were normal. Histopathological tests showed leucocytoclastic vasculitis, confirming the diagnosis of acute haemorrhagic oedema of infancy. The patient achieved complete recovery after 2 weeks with no recurrence.
Proteomic analysis of swine serum following highly virulent classical swine fever virus infection
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Guo Huan-cheng
2011-03-01
Full Text Available Abstract Background Classical swine fever virus (CSFV belongs to the genus Pestivirus within the family Flaviviridae. Virulent strains of classical swine fever virus (CSFV cause severe disease in pigs characterized by immunosuppression, thrombocytopenia and disseminated intravascular coagulation, which causes significant economic losses to the pig industry worldwide. Methods To reveal proteomic changes in swine serum during the acute stage of lethal CSFV infection, 5 of 10 pigs were inoculated with the virulent CSFV Shimen strain, the remainder serving as uninfected controls. A serum sample was taken at 3 days post-infection from each swine, at a stage when there were no clinical symptoms other than increased rectal temperatures (≥40°C. The samples were treated to remove serum albumin and immunoglobulin (IgG, and then subjected to two-dimension differential gel electrophoresis. Results Quantitative intensity analysis revealed 17 protein spots showing at least 1.5-fold quantitative alteration in expression. Ten spots were successfully identified by MALDI-TOF MS or LTQ MS. Expression of 4 proteins was increased and 6 decreased in CSFV-infected pigs. Functions of these proteins included blood coagulation, anti-inflammatory activity and angiogenesis. Conclusion These proteins with altered expression may have important implications in the pathogenesis of classical swine fever and provide a clue for identification of biomarkers for classical swine fever early diagnosis.
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Simon Delgado
2008-04-01
Full Text Available A small focus of hemorrhagic fever (HF cases occurred near Cochabamba, Bolivia, in December 2003 and January 2004. Specimens were available from only one fatal case, which had a clinical course that included fever, headache, arthralgia, myalgia, and vomiting with subsequent deterioration and multiple hemorrhagic signs. A non-cytopathic virus was isolated from two of the patient serum samples, and identified as an arenavirus by IFA staining with a rabbit polyvalent antiserum raised against South American arenaviruses known to be associated with HF (Guanarito, Machupo, and Sabiá. RT-PCR analysis and subsequent analysis of the complete virus S and L RNA segment sequences identified the virus as a member of the New World Clade B arenaviruses, which includes all the pathogenic South American arenaviruses. The virus was shown to be most closely related to Sabiá virus, but with 26% and 30% nucleotide difference in the S and L segments, and 26%, 28%, 15% and 22% amino acid differences for the L, Z, N, and GP proteins, respectively, indicating the virus represents a newly discovered arenavirus, for which we propose the name Chapare virus. In conclusion, two different arenaviruses, Machupo and Chapare, can be associated with severe HF cases in Bolivia.
African Swine Fever Virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs that has significant economic consequences for the swine industry. The control of African Swine Fever (ASF) has been hampered by the unavailability of vaccines. Successful experi...
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TELISSA C. KASSAR
Full Text Available ABSTRACT Yellow fever is an arthropod-borne viral disease that still poses high public health concerns, despite the availability of an effective vaccine. The development of recombinant viruses is of utmost importance for several types of studies, such as those aimed to dissect virus-host interactions and to search for novel antiviral strategies. Moreover, recombinant viruses expressing reporter genes may greatly facilitate these studies. Here, we report the construction of a recombinant yellow fever virus (YFV expressing Gaussia luciferase (GLuc (YFV-GLuc. We show, through RT-PCR, sequencing and measurement of GLuc activity, that stability of the heterologous gene was maintained after six passages. Furthermore, a direct association between GLuc expression and viral replication was observed (r2=0.9967, indicating that measurement of GLuc activity may be used to assess viral replication in different applications. In addition, we evaluated the use of the recombinant virus in an antiviral assay with recombinant human alfa-2b interferon. A 60% inhibition of GLuc expression was observed in cells infected with YFV-GLuc and incubated with IFN alfa-2b. Previously tested on YFV inhibition by plaque assays indicated a similar fold-decrease in viral replication. These results are valuable as they show the stability of YFV-GLuc and one of several possible applications of this construct.
The phylogeny of yellow fever virus 17D vaccines.
Stock, Nina K; Boschetti, Nicola; Herzog, Christian; Appelhans, Marc S; Niedrig, Matthias
2012-02-01
In recent years the safety of the yellow fever live vaccine 17D came under scrutiny. The focus was on serious adverse events after vaccinations that resemble a wild type infection with yellow fever and whose reasons are still not known. Also the exact mechanism of attenuation of the vaccine remains unknown to this day. In this context, the standards of safety and surveillance in vaccine production and administration have been discussed. Therein embodied was the demand for improved documentation of the derivation of the seed virus used for yellow fever vaccine production. So far, there was just a historical genealogy available that is based on source area and passage level. However, there is a need for a documentation based on molecular information to get better insights into the mechanisms of pathology. In this work we sequenced the whole genome of different passages of the YFV-17D strain used by Crucell Switzerland AG for vaccine production. Using all other publically available 17D full genome sequences we compared the sequence variance of all vaccine strains and oppose a phylogenetic tree based on full genome sequences to the historical genealogy. Copyright © 2011 Elsevier Ltd. All rights reserved.
Four-segmented Rift Valley fever virus-based vaccines can be applied safely in ewes during pregnancy
Wichgers Schreur, Paul J.; Keulen, van Lucien; Kant-Eenbergen, Jet; Kortekaas, Jeroen
2017-01-01
Rift Valley fever virus (RVFV) causes severe and recurrent outbreaks on the African continent and the Arabian Peninsula and continues to expand its habitat. This mosquito-borne virus, belonging to the genus Phlebovirus of the family Bunyaviridae contains a tri-segmented negative-strand RNA
Molecular analysis of yellow fever virus 17DD vaccine strain
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Paulo R. Post
1991-06-01
Full Text Available The Oswaldo Cruz Foundation produces most of the yellow fever (YF vaccine prepared world wide. As part of a broader approach to determine the genetic variability in YF l7D seeds and vaccines and its relevance to viral attenuation the 17DD virus was purifed directly from chick embryo homogenates which is the source of virus used for vaccination of millions of people in Brazil and other countries for half a century. Neutralization and hemagglutination tests showed that the purified virus is similar to the original stock. Furthermore, radioimmune precipitation of 35S-methionine-labeled viral proteins using mouse hyperimmune ascitic fluid revealed identical patterns for the purified 17DD virus and the YF l7D-204 strain except for the 17DD E protein which migrated slower on SDS-PAGE. This difference is likely to be due to N-linked glycosylation. Finally, comparison by northern blot nybridization of virion RNAs of purified 17DD with two other strains of YF virus only fenome-sized molecules for all three viruses. These observations suggest that vaccine phenotype is primarily associated with the accumulation of mutations.
Emerging rabbit haemorrhagic disease virus 2 (RHDV2) at the gates of the African continent.
Martin-Alonso, Aarón; Martin-Carrillo, Natalia; Garcia-Livia, Katherine; Valladares, Basilio; Foronda, Pilar
2016-10-01
Until the beginning of this decade, the genetic characterization of rabbit haemorrhagic disease virus (RHDV) from Iberian Peninsula had revealed the existence of two genogroups, G1 and sporadically G6. In 2010, the new emerging rabbit haemorrhagic disease variant, RHDV2 or RHDVb, was described in France, from where it has rapidly spread throughout Europe, including Iberian Peninsula countries. Nevertheless, although cases of rabbit haemorrhagic disease (RHD) have been reported in the Canary Islands, a Spanish archipelago located 100km off the coast of Morocco, no genetic characterization of RHDV had been carried out. Consequently, in order to identify the circulating RHDV strains in this archipelago, liver samples of six farm rabbits and fifteen wild rabbits were collected from several areas of the largest island, Tenerife, and analyzed for the presence of RHDV by antigen capture double antibody sandwich ELISA. In case of positive ELISA result, we amplified and sequenced two fragments of the vp60 gene, which were concatenated for phylogenetic purposes. The sequences analysis revealed the presence of RHDV2 in both farm and wild rabbits from several areas of Tenerife. This result constitutes the first finding of RHDV2 in the Canary Islands. These RHDV2 strains found in Tenerife shared two exclusive SNPs that have not been observed in the rest of RHDV2 strains. The identification of RHDV2 and the absence of classic RHDV strains in this study suggest that RHDV2 may be replacing classic strains in Tenerife, as has been also proposed in Iberian Peninsula, France and Azores. Given the proximity of the Canary Islands to the African continent, this result should raise awareness about a possible dispersal of RHDV2 from the Canary Islands to the North of Africa. Copyright © 2016 Elsevier B.V. All rights reserved.
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Thae’ Zar Chi Bo
2016-02-01
Full Text Available A cross-sectional study was conducted in urban community of Thanlyin Township, Yangon Region during 2014 to determine Aedes larval indices and the occurrence of Dengue Haemorrhagic Fever (DHF within past one year. A total of 327 households and 1491 members were included in the study. Aedes larval indices detected in this study were 25.7% for house index, 15.5% for container index and 48.0% for Breteau index. The occurrence of DHF among households and family members were 2.1% (95% CI: 0.9%, 4.4% and 0.6% (95% CI: 0.3%, 1.1%, respectively. The occurrence was highest among 5 to 14 years age-group. No case was reported among persons with equal or more than 60 years of age. Mortality and case fatality rates were 0% during study period. Larval positivity among households was significantly related to sufficiency of family income and number of water container they have. Surveillance and control procedures for both DHF and vector should be intensified in urban area. Awareness and participation of the community in prevention and control of DHF should also be raised. Socioeconomic status as well as proper water supply and storage should be improved in urban area.
A fatal yellow fever virus infection in China: description and lessons
Chen, Zhihai; Liu, Lin; Lv, Yanning; Zhang, Wei; Li, Jiandong; Zhang, Yi; Di, Tian; Zhang, Shuo; Liu, Jingyuan; Li, Jie; Qu, Jing; Hua, Wenhao; Li, Chuan; Wang, Peng; Zhang, Quanfu; Xu, Yanli; Jiang, Rongmeng; Wang, Qin; Chen, Lijuan; Wang, Shiwen; Pang, Xinghuo; Liang, Mifang; Ma, Xuejun; Li, Xingwang; Wang, Quanyi; Zhang, Fujie; Li, Dexin
2016-01-01
Yellow fever (YF) is a viral disease endemic to the tropical regions of Africa and South America. An outbreak of YF has been occurring in Angola, since the beginning of 2016. In March 2016, a 32-year-old Chinese man who returned from Angola was hospitalized and diagnosed with the first case of imported YF in China. Clinical observations, blood viral RNA detection, serological testing and treatments for the patient were performed daily. The virus was isolated in Vero cells, and the complete viral genome was sequenced and analyzed using the next-generation genomic sequencing platform. The patient presented with hemorrhagic fever, jaundice and oliguria at day 3 after onset, which rapidly progressed to multisystem organ failure with extremely elevated liver, pancreatic and myocardial enzymes. The patient died despite the intensive supportive treatments that were performed. A liver biopsy showed severe and multilobular necrosis. Viral RNA was detectable throughout the clinical course of the disease. Whole-genomic sequence analysis revealed that the virus belongs to the Angola71 genotype. Although the virus has been circulating in Angola for 45 years, only 14 amino-acid substitutions and no amino-acid changes were observed in the membrane and envelope proteins compared with the virus collected in 1971. The presence of this imported YF case in China indicated that with the increase in business travel among countries, YF outbreaks in Africa can lead to the international spread of the disease. The production and use of YF vaccines is, therefore, an urgent issue. PMID:27406389
Fischer, E.A.J.; Boender, G.J.; Koeijer, de A.A.; Nodelijk, G.; Roermund, van H.J.W.
2011-01-01
Rift Valley Fever (RVF) is a zoonotic vector-borne infection and causes a potentially severe disease in both humans and young animals. The Ministry of Economic Affairs, Agriculture and Innovation (EL&I) is interested in the risk of an outbreak of Rift Valley Fever virus (RVFV) for the
E2, the major envelope glycoprotein of Classical Swine Fever Virus (CSFV), is involved in several critical virus functions including cell attachment, host range susceptibility, and virulence in natural hosts. Functional structural analysis of E2 based on Wimley-White interfacial hydrophobicity dis...
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Rania Ali El Hadi Mohamed
2017-05-01
Full Text Available Objective: To screen hemorrhagic fever viruses inside wild populations of ticks collected from Riyadh, Saudi Arabia between January and March 2016. Methods: Ticks were identified depending on their morphological features using classical keys then grouped into pools. Ticks in each pool were processed separately using the sterile pestles and mortars. Viral RNA was extracted using Qiagen RNeasy Mini Kit and Qiagen RNAeasy Columns (Qiagen, Hilden, Germany according to the instructions of manufacturers. A total number of 1 282 hard ticks were collected, and 582 of them were precisely identified then screened for the presence of arboviruses using quantitative real-time PCR. The four species were screened for six viruses: Rift Valley fever virus (RVFV, Chikungunya virus (CHIKV, Crimean-Congo hemorrhagic fever virus (CCHFV, Alkhurma virus (INKV, Sindbis virus (SINV, and Pan Hanta virus (HANTA. CT value for the negative control (RNA free water was zero. Negative and positive controls were tested for each test to confirm the specificity of the selected primer pairs. SYBR Green One step RT-PCR Master Mix (KAPA Biosystems, Boston, MA was tested along with primers. Results: Ticks identification resulted into four species: Hyalomma schulzei, Hyalomma onatoli, Boophilus kdhlsi, and Hyalomm dromedarii. All the ticks’ species (except Boophilus kdhlsi were positive for the following viruses: SINV, RVFV, CHIKV, and CCHFV. While HANTA viruses have been detected in a single species (Hyalomm dromedarii. Conclusions: According to our knowledge this research may be one of the pioneer studies in Kingdom of Saudi Arabia. Incrimination of the above mentioned ticks species as well as their vectorial capacity are highly recommended for investigation in the upcoming researches.
Epidemic yellow fever in Borno State of Nigeria: characterisation of hospitalised patients.
Ekenna, O; Chikwem, J O; Mohammed, I; Durojaiye, S O
2010-01-01
In 1990, an outbreak of a febrile illness with high mortality was reported in border villages, later spreading to other areas of Borno State of Nigeria. To present a report of the investigation of that outbreak, with emphasis on the characterisation of hospitalised patients. Selected centres reporting cases of acute febrile illness during the months of August to December, 1990 were visited, to establish surveillance. Case investigation forms were used to obtain clinical and demographic data; and blood samples were obtained from patients for analyses. Only hospitalised patients with adequate clinical information from three centres were included in the analysis. The outbreak, which involved five of the six health zones in the state, and spread into adjoining Gongola state and the Cameroun Republic, was caused by the yellow fever virus. Fever, central nervous system (CNS) involvement, jaundice and haemorrhage were the most common clinical manifestations of 102 hospitalised patients. Eighty -three (81%) of hospitalised patients died and most within two days of admission. CNS manifestations were more common in dying patients than in survivors. The reasons for this rare outbreak of yellow fever in the dry Savannah belt of Borno State remain unclear. Improved surveillance and more effective prevention strategies are needed to avert the recurrence of such outbreaks.
Lam, Tommy Tsan-Yuk; Liu, Wei; Bowden, Thomas A; Cui, Ning; Zhuang, Lu; Liu, Kun; Zhang, Yao-Yun; Cao, Wu-Chun; Pybus, Oliver G
2013-03-01
In 2009, a novel Bunyavirus, called severe fever with thrombocytopenia syndrome virus (SFTSV) was identified in the vicinity of Huaiyangshan, China. Clinical symptoms of this zoonotic virus included severe fever, thrombocytopenia, and leukocytopenia, with a mortality rate of ~10%. By the end of 2011 the disease associated with this pathogen had been reported from eleven Chinese provinces and human-to-human transmission suspected. However, current understanding of the evolution and molecular epidemiology of SFTSV before and after its identification is limited. To address this we undertake phylogenetic, evolutionary and structural analyses of all available SFTSV genetic sequences, including a new SFTSV complete genome isolated from a patient from Henan in 2011. Our discovery of a mosaic L segment sequence, which is descended from two major circulating lineages of SFTSV in China, represents the first evidence that homologous recombination plays a role in SFTSV evolution. Selection analyses indicate that negative selection is predominant in SFTSV genes, yet differences in selective forces among genes are consistent between Phlebovirus species. Further analysis reveals structural conservation between SFTSV and Rift Valley fever virus in the residues of their nucleocapsids that are responsible for oligomerisation and RNA-binding, suggesting the viruses share similar modes of higher-order assembly. We reconstruct the epidemic history of SFTSV using molecular clock and coalescent-based methods, revealing that the extant SFTSV lineages originated 50-150 years ago, and that the viral population experienced a recent growth phase that concurs with and extends the earliest serological reports of SFTSV infection. Taken together, our combined structural and phylogenetic analyses shed light into the evolutionary behaviour of SFTSV in the context of other, better-known, pathogenic Phleboviruses. Copyright © 2012 Elsevier B.V. All rights reserved.
Ebola hemorrhagic fever associated with novel virus strain, Uganda, 2007-2008.
Wamala, Joseph F; Lukwago, Luswa; Malimbo, Mugagga; Nguku, Patrick; Yoti, Zabulon; Musenero, Monica; Amone, Jackson; Mbabazi, William; Nanyunja, Miriam; Zaramba, Sam; Opio, Alex; Lutwama, Julius J; Talisuna, Ambrose O; Okware, Sam I
2010-07-01
During August 2007-February 2008, the novel Bundibugyo ebolavirus species was identified during an outbreak of Ebola viral hemorrhagic fever in Bundibugyo district, western Uganda. To characterize the outbreak as a requisite for determining response, we instituted a case-series investigation. We identified 192 suspected cases, of which 42 (22%) were laboratory positive for the novel species; 74 (38%) were probable, and 77 (40%) were negative. Laboratory confirmation lagged behind outbreak verification by 3 months. Bundibugyo ebolavirus was less fatal (case-fatality rate 34%) than Ebola viruses that had caused previous outbreaks in the region, and most transmission was associated with handling of dead persons without appropriate protection (adjusted odds ratio 3.83, 95% confidence interval 1.78-8.23). Our study highlights the need for maintaining a high index of suspicion for viral hemorrhagic fevers among healthcare workers, building local capacity for laboratory confirmation of viral hemorrhagic fevers, and institutionalizing standard precautions.
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Müller Marcel A
2005-02-01
Full Text Available Abstract Ten potential reference genes were compared for their use in experiments investigating cellular mRNA expression of virus infected cells. Human cell lines were infected with Cytomegalovirus, Human Herpesvirus-6, Camelpox virus, SARS coronavirus or Yellow fever virus. The expression levels of these genes and the viral replication were determined by real-time PCR. Genes were ranked by the BestKeeper tool, the GeNorm tool and by criteria we reported previously. Ranking lists of the genes tested were tool dependent. However, over all, β-actin is an unsuitable as reference gene, whereas TATA-Box binding protein and peptidyl-prolyl-isomerase A are stable reference genes for expression studies in virus infected cells.
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Fahnøe, Ulrik; Orton, Richard; Höper, Dirk
Next Generation Sequencing (NGS) has rapidly become the preferred technology in nucleotide sequencing, and can be applied to unravel molecular adaptation of RNA viruses such as Classical Swine Fever Virus (CSFV). However, the detection of low frequency variants within viral populations by NGS...... is affected by errors introduced during sample preparation and sequencing, and so far no definitive solution to this problem has been presented....
Lasecka, Lidia; Bin-Tarif, Abdelghani; Bridgen, Anne; Juleff, Nicholas; Waters, Ryan A; Baron, Michael D
2015-01-01
Nairobi sheep disease virus (NSDV; also called Ganjam virus in India) is a bunyavirus of the genus Nairovirus. It causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%. The virus is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus (CCHFV). Little is currently known about the biology of NSDV. We have generated specific antibodies against the virus nucleocapsid protein (N) and polymerase (L) and used these to characterise NSDV in infected cells and to study its distribution during infection in a natural host. Due to its large size and the presence of a papain-like protease (the OTU-like domain) it has been suggested that the L protein of nairoviruses undergoes an autoproteolytic cleavage into polymerase and one or more accessory proteins. Specific antibodies which recognise either the N-terminus or the C-terminus of the NSDV L protein showed no evidence of L protein cleavage in NSDV-infected cells. Using the specific anti-N and anti-L antibodies, it was found that these viral proteins do not fully colocalise in infected cells; the N protein accumulated near the Golgi at early stages of infection while the L protein was distributed throughout the cytoplasm, further supporting the multifunctional nature of the L protein. These antibodies also allowed us to gain information about the organs and cell types targeted by the virus in vivo. We could detect NSDV in cryosections prepared from various tissues collected post-mortem from experimentally inoculated animals; the virus was found in the mucosal lining of the small and large intestine, in the lungs, and in mesenteric lymph nodes (MLN), where NSDV appeared to target monocytes and/or macrophages.
Antibodies against severe fever with Thrombocytopenia syndrome Virus in healthy persons, China, 2013
Zhang Lei, Lei; Sun, J.; Yan, J.; Huakun, L.; Chai, C.Y.; Sun, Y.; Shao, B.; Jiang, J.D.; Chen, Z.; Kortekaas, J.A.; Zhang, Y.
2014-01-01
In June 2013, a subclinical infection with severe fever with thrombocytopenia syndrome virus (SFTSV) was detected in Zhejiang Province, China, prompting seroprevalence studies in 6 districts within the province. Of 986 healthy persons tested, 71 had IgG antibodies against SFTSV. This finding
Innate Immune Response to Rift Valley Fever Virus in Goats
Nfon, Charles K.; Marszal, Peter; Zhang, Shunzhen; Weingartl, Hana M.
2012-01-01
Rift Valley fever (RVF), a re-emerging mosquito-borne disease of ruminants and man, was endemic in Africa but spread to Saudi Arabia and Yemen, meaning it could spread even further. Little is known about innate and cell-mediated immunity to RVF virus (RVFV) in ruminants, which is knowledge required for adequate vaccine trials. We therefore studied these aspects in experimentally infected goats. We also compared RVFV grown in an insect cell-line and that grown in a mammalian cell-line for differences in the course of infection. Goats developed viremia one day post infection (DPI), which lasted three to four days and some goats had transient fever coinciding with peak viremia. Up to 4% of peripheral blood mononuclear cells (PBMCs) were positive for RVFV. Monocytes and dendritic cells in PBMCs declined possibly from being directly infected with virus as suggested by in vitro exposure. Infected goats produced serum IFN-γ, IL-12 and other proinflammatory cytokines but not IFN-α. Despite the lack of IFN-α, innate immunity via the IL-12 to IFN-γ circuit possibly contributed to early protection against RVFV since neutralising antibodies were detected after viremia had cleared. The course of infection with insect cell-derived RVFV (IN-RVFV) appeared to be different from mammalian cell-derived RVFV (MAM-RVFV), with the former attaining peak viremia faster, inducing fever and profoundly affecting specific immune cell subpopulations. This indicated possible differences in infections of ruminants acquired from mosquito bites relative to those due to contact with infectious material from other animals. These differences need to be considered when testing RVF vaccines in laboratory settings. PMID:22545170
African swine fever virus (ASFV) is the etiological agent of a contagious and often lethal viral disease of domestic pigs. There are no vaccines to control Africa swine fever (ASF). Experimental vaccines have been developed using genetically modified live attenuated ASFVs obtained by specifically de...
Silvério, D; Lopes, A M; Melo-Ferreira, J; Magalhães, M J; Monterroso, P; Serronha, A; Maio, E; Alves, P C; Esteves, P J; Abrantes, J
2018-02-11
Rabbit haemorrhagic disease (RHD) is a viral disease that affects the European rabbit. RHD was detected in 1984 in China and rapidly disseminated worldwide causing a severe decline in wild rabbit populations. The aetiological agent, rabbit haemorrhagic disease virus (RHDV), is an RNA virus of the family Caliciviridae, genus Lagovirus. Pathogenic (G1-G6 or variants GI.1a-GI.1d) and non-pathogenic strains (GI.4) have been characterized. In 2010, a new variant of RHDV, RHDV2/RHDVb/GI.2, was detected in France. GI.2 arrived to the Iberian Peninsula in 2011, and several recombination events were reported. Here, we sequenced full genomes of 19 samples collected in Portugal between 2014 and 2016. New GI.2 recombinant strains were detected, including triple recombinants. These recombinants possess a non-structural protein p16 related to a non-pathogenic strain. Evolutionary analyses were conducted on GI.2 VP60 sequences. Estimated time to the most recent common ancestor (tMRCA) suggests an emergence of GI.2 in July 2008, not distant from its first detection in 2010. This is the first study on GI.2 evolution and highlights the need of continued monitoring and characterization of complete genome sequences when studying lagoviruses' evolution. © 2018 Blackwell Verlag GmbH.
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Bøtner, Anette; Belsham, Graham
2012-01-01
of an outbreak of disease before it has been recognized. The survival of foot-and-mouth disease virus, classical swine fever virus, bovine viral diarrhoea virus and swine influenza virus, which belong to three different RNA virus families plus porcine parvovirus (a DNA virus) was examined under controlled...... conditions. For each RNA virus, the virus survival in farm slurry under anaerobic conditions was short (generally ≤1h) when heated (to 55°C) but each of these viruses could retain infectivity at cool temperatures (5°C) for many weeks. The porcine parvovirus survived considerably longer than each of the RNA...... viruses under all conditions tested. The implications for disease spread are discussed....
Modulation of Translation Initiation Efficiency in Classical Swine Fever Virus
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Friis, Martin Barfred; Rasmussen, Thomas Bruun; Belsham, Graham J.
Modulation of translation initiation efficiency on classical swine fever virus (CSFV) RNA can be achieved by targeted mutations within the internal ribosome entry site (IRES). In this study, the nucleotides 47 to 427, including the IRES region of the wt CSFV strain Paderborn, were amplified...... and inserted, under T7 promoter control, into mono- and dicistronic plasmids containing the reporter genes rLuc and fLuc. Mutant fragments of the IRES sequence were generated by overlap PCR and inserted into the reporter plasmids. To evaluate IRES functionality, translation of the rLUC was placed under...... viruses were obtained after one cell culture passage from constructs with more than 75 % translation efficiency compared to the wildtype IRES. cDNA was generated from these clones and sequenced to verify the maintenance of the changes in the IRES. These results show that full-length viable mutant viruses...
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Camille Escadafal
Full Text Available Crimean-Congo hemorrhagic fever (CCHF is a zoonosis caused by a Nairovirus of the family Bunyaviridae. Infection is transmitted to humans mostly by Hyalomma ticks and also by direct contact with the blood or tissues of infected humans or viremic livestock. Clinical features usually include a rapid progression characterized by hemorrhage, myalgia and fever, with a lethality rate up to 30%. CCHF is one of the most widely distributed viral hemorrhagic fevers and has been reported in Africa, the Middle East and Asia, as well as parts of Europe. There is no approved vaccine or specific treatment against CCHF virus (CCHFV infections. In this context, an accurate diagnosis as well as a reliable surveillance of CCHFV infections is essential. Diagnostic techniques include virus culture, serology and molecular methods, which are now increasingly used. The European Network for the Diagnostics of "Imported" Viral Diseases organized the first international external quality assessment of CCHVF molecular diagnostics in 2011 to assess the efficiency and accurateness of CCHFV molecular methods applied by expert laboratories. A proficiency test panel of 15 samples was distributed to the participants including 10 different CCHFV preparations generated from infected cell cultures, a preparation of plasmid cloned with the nucleoprotein of CCHFV, two CCHFV RNA preparations and two negative controls. Forty-four laboratories worldwide participated in the EQA study and 53 data sets were received. Twenty data sets (38% met all criteria with optimal performance, 10 (19% with acceptable performance, while 23 (43% reported results showing a need for improvement. Differences in performance depended on the method used, the type of strain tested, the concentration of the sample tested and the laboratory performing the test. These results indicate that there is still a need for improving testing conditions and standardizing protocols for the molecular detection of Crimean
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Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat; Jokinen, Jenny; Lukashevich, Igor S.; Pushko, Peter
2014-01-01
Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficient in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. - Highlights: • The iDNA ® platform combines advantages of DNA and live attenuated vaccines. • Yellow fever (YF) 17D vaccine was launched from iDNA plasmid in vitro and in vivo. • Safety of iDNA-generated 17D virus was confirmed in AG129 mice. • BALB/c mice seroconverted after a single-dose vaccination with iDNA. • YF virus-neutralizing response was elicited in iDNA-vaccinated mice
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Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat [Medigen, Inc., 8420 Gas House Pike, Suite S, Frederick, MD 21701 (United States); Jokinen, Jenny; Lukashevich, Igor S. [Department of Pharmacology and Toxicology, School of Medicine, Center for Predictive Medicine and Emerging Infectious Diseases, University of Louisville, Louisville, KY (United States); Pushko, Peter, E-mail: ppushko@medigen-usa.com [Medigen, Inc., 8420 Gas House Pike, Suite S, Frederick, MD 21701 (United States)
2014-11-15
Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficient in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. - Highlights: • The iDNA{sup ®} platform combines advantages of DNA and live attenuated vaccines. • Yellow fever (YF) 17D vaccine was launched from iDNA plasmid in vitro and in vivo. • Safety of iDNA-generated 17D virus was confirmed in AG129 mice. • BALB/c mice seroconverted after a single-dose vaccination with iDNA. • YF virus-neutralizing response was elicited in iDNA-vaccinated mice.
Mahar, Jackie E; Hall, Robyn N; Peacock, David; Kovaliski, John; Piper, Melissa; Mourant, Roslyn; Huang, Nina; Campbell, Susan; Gu, Xingnian; Read, Andrew; Urakova, Nadya; Cox, Tarnya; Holmes, Edward C; Strive, Tanja
2017-11-01
Rabbit haemorrhagic disease virus 2 (RHDV2; Lagovirus GI.2) is a pathogenic calicivirus that affects European rabbits ( Oryctolagus cuniculus ) and various hare ( Lepus ) species. GI.2 was first detected in France in 2010 and subsequently caused epidemics in wild and domestic lagomorph populations throughout Europe. In May 2015 GI.2 was detected in Australia. Within 18 months of its initial detection GI.2 had spread to all Australian states and territories and rapidly became the dominant circulating strain, replacing Rabbit haemorrhagic disease virus (RHDV/GI.1) in mainland Australia. Reconstruction of the evolutionary history of 127 Australian GI.2 isolates revealed that the virus arrived in Australia at least several months before its initial description and likely circulated unnoticed in wild rabbit populations in the east of the continent prior to its detection. GI.2 sequences isolated from five hares clustered with sequences from sympatric rabbit populations sampled contemporaneously, indicating multiple spillover events into hares rather than an adaptation of the Australian GI.2 to a new host. Since the presence of GI.2 in Australia may have wide ranging consequences for rabbit biocontrol, particularly with the release of the novel biocontrol agent GI.1a/RHDVa-K5 in March 2017, ongoing surveillance is critical to understanding the interactions of the various lagoviruses in Australia, and their impact on host populations. IMPORTANCE This study describes the spread and distribution of Rabbit Haemorrhagic Disease virus 2 (GI.2) in Australia since its first detection in May 2015. Within the first 18 months following its detection, RHDV2 spread from east to west across the continent and became the dominant strain in all mainland states of Australia. This has important implications for pest animal management and for owners of pet and farmed rabbits, as there is currently no effective vaccine available in Australia for GI.2. The closely related RHDV (GI.1) is used
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
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.
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.
Vectors of Crimean Congo Hemorrhagic Fever Virus in Iran
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Zakkyeh Telmadarraiy
2015-10-01
Full Text Available Background: Ticks are important vectors and reservoirs of Crimean Congo Hemorrhagic Fever (CCHF virus. Human beings may be infected whenever the normal life cycle of the infected ticks on non- human vertebrate hosts is interrupted by the undesirable presence of humans in the cycle. A total of 26 species of Argasid and Ixodid ticks have been recorded in Iran; including nine Hyalomma, two Rhipicephalus, two Dermacentor, five Haemaphysalis, two Boophilus, one Ixodes and two Argas as well as three Ornithodoros species as blood sucking ectoparasites of livestock and poultries. The present paper reviews tick vectors of CCHF virus in Iran, focusing on the role of ticks in different provinces of Iran using reverse transcription polymerase chain reaction (RT-PCR assay.Methods: During ten years study, 1054 tick specimens; including two species of Argasidae and 17 species of Ixodidae were examined for their infection to CCHF virus genome. The output of all studies as well as related publications were discussed in the current paper.Results: The results show that Rhipicephalus sanguineus, Hyalomma marginatum, H. anatolicum, H. asiaticum and H. dromedarii were known as the most frequent species which were positive for CCHF virus.Conclusion: The status of ticks which were positive for CCHF virus revealed that unlike the most common idea that Hyalomma species are the most important vectors of CCHF virus, other ticks including Rhipicephalus,Haemaphysalis and Dermacentor can be reservoir of this virus; thus, considering geographical distribution, type of host and environmental conditions, different tick control measurements should be carried out in areas with high incidence of CCHF disease.
Vectors of Crimean Congo Hemorrhagic Fever Virus in Iran
Telmadarraiy, Zakkyeh; Chinikar, Sadegh; Vatandoost, Hassan; Faghihi, Faezeh; Hosseini-Chegeni, Asadollah
2015-01-01
Background: Ticks are important vectors and reservoirs of Crimean Congo Hemorrhagic Fever (CCHF) virus. Human beings may be infected whenever the normal life cycle of the infected ticks on non-human vertebrate hosts is interrupted by the undesirable presence of humans in the cycle. A total of 26 species of Argasid and Ixodid ticks have been recorded in Iran; including nine Hyalomma, two Rhipicephalus, two Dermacentor, five Haemaphysalis, two Boophilus, one Ixodes and two Argas as well as three Ornithodoros species as blood sucking ectoparasites of livestock and poultries. The present paper reviews tick vectors of CCHF virus in Iran, focusing on the role of ticks in different provinces of Iran using reverse transcription polymerase chain reaction (RT-PCR) assay. Methods: During ten years study, 1054 tick specimens; including two species of Argasidae and 17 species of Ixodidae were examined for their infection to CCHF virus genome. The output of all studies as well as related publications were discussed in the current paper. Results: The results show that Rhipicephalus sanguineus, Hyalomma marginatum, H. anatolicum, H. asiaticum and H. dromedarii were known as the most frequent species which were positive for CCHF virus. Conclusion: The status of ticks which were positive for CCHF virus revealed that unlike the most common idea that Hyalomma species are the most important vectors of CCHF virus, other ticks including Rhipicephalus, Haemaphysalis and Dermacentor can be reservoir of this virus; thus, considering geographical distribution, type of host and environmental conditions, different tick control measurements should be carried out in areas with high incidence of CCHF disease. PMID:26623426
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)
Haemorrhage from Pancreatic Pseudocysts Presenting as Upper Gastrointestinal Haemorrhage
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Giuseppe Garcea
2004-04-01
Full Text Available Haemorrhage is a rare but frequently fatal complication of pancreatic pseudocysts. The high mortality associated with pancreatic haemorrhage makes prompt and aggressive management essential. Occasionally, haemorrhage may present atypically, leading to delay in its diagnosis and management. This report details a case of pancreatic haemorrhage presenting as an upper gastrointestinal bleed and discusses the subsequent management. When managing patients with pancreatic pseudocysts who present with the stigmata of upper gastrointestinal bleeding, the possibility that the bleeding originates from the pancreas must always be borne in mind.
Naing, Cho; Poovorawan, Yong; Mak, Joon Wah; Aung, Kyan; Kamolratankul, Pirom
2015-06-01
The present study aimed to assess the cost-utility analysis of using an adjunctive recombinant activated factor VIIa (rFVIIa) in children for controlling life-threatening bleeding in dengue haemorrhagic fever (DHF)/dengue shock syndrome (DSS). We constructed a decision-tree model, comparing a standard care and the use of an additional adjuvant rFVIIa for controlling life-threatening bleeding in children with DHF/DSS. Cost and utility benefit were estimated from the societal perspective. The outcome measure was cost per quality-adjusted life years (QALYs). Overall, treatment with adjuvant rFVIIa gained QALYs, but the total cost was higher. The incremental cost-utility ratio for the introduction of adjuvant rFVIIa was $4241.27 per additional QALY. Sensitivity analyses showed the utility value assigned for calculation of QALY was the most sensitive parameter. We concluded that despite high cost, there is a role for rFVIIa in the treatment of life-threatening bleeding in patients with DHF/DSS.
Struthers, J K; Swanepoel, R
1982-06-01
A non-structural protein of mol. wt. 34 X 10(3) was demonstrated in the nuclei of Rift Valley fever virus-infected Vero cells by SDS-polyacrylamide gel electro-phoresis. The protein appears to correspond to the virus-induced antigen demonstrated by indirect immunofluorescence in intranuclear inclusions.
Febres hemorrágicas por vírus no Brasil Viral hemorrhagic fevers in Brazil
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Luiz Tadeu Moraes Figueiredo
2006-04-01
Full Text Available Chamando a atenção para as febres hemorrágicas por vírus, que em sua maioria tem escassa informação divulgada e provavelmente são subnotificadas, mostra-se neste artigo casos clínicos das 4 doenças deste tipo que ocorrem no Brasil: febre amarela, dengue hemorrágico/síndrome de choque do dengue, febre hemorrágica por arenavírus e síndrome pulmonar e cardiovascular por hantavírus. Também, relevantes aspectos clínicos, laboratoriais e epidemiológicos destas viroses são aqui abordados. São doenças que têm alta letalidade e induzem extravasamento capilar e coagulopatia, que podem ser evidenciados pela elevação do hematócrito e plaquetopenia. A suspeita clínica e o tratamento precoce são fundamentais à sobrevida dos pacientes.To call atention to viral hemorrhagic fevers, diseases that are mostly underdivulged and, probably, undereported, we present here case reports of the 4 diseases of this kind that occur in Brazil: yellow fever, dengue haemorrhagic fever/dengue shock syndrome, arenavirus haemorrhagic fever and hantavirus cardiopulmonary syndrome. Relevant clinical, epidemiological and laboratorial diagnostic aspects of these viral haemorrhagic fevers are also shown here. These diseases have a high case fatality rate, induce capillary leaking and blood coagulation disturbances that are evidenced by hemoconcentrantion and thrombocytopenia. An early clinical diagnosis and treatment is fundamental for patient survival.
Mohammadian, Maria; Chinikar, Sadegh; Telmadarraiy, Zakkyeh; Vatandoost, Hassan; Oshaghi, Mohammad Ali; Hanafi-Bojd, Ahmad Ali; Sedaghat, Mohammad Mehdi; Noroozi, Mehdi; Faghihi, Faezeh; Jalali, Tahmineh; Khakifirouz, Sahar; Shahhosseini, Nariman; Farhadpour, Firoozeh
2016-01-01
Background: Crimean-Congo Hemorrhagic Fever (CCHF) is a feverous and hemorrhagic disease endemic in some parts of Iran and caused by an arbovirus related to Bunyaviridae family and Nairovirusgenus. The main virus reservoir in the nature is ticks, however small vertebrates and a wide range of domestic and wild animals are regarded as reservoir hosts. This study was conducted to determine the infection rate of CCHF virus in hard ticks of Sarpole-Zahab County, Kermanshah province, west of Iran. Methods: From total number of 851 collected ticks from 8 villages, 131 ticks were selected randomlyand investigated for detection of CCHF virus using RT-PCR. Results: The virus was found in 3.8% of the tested ticks. Hyalommaanatolicum, H. asiaticum and Rhipicephalus sanguineus species were found to have viral infection, with the highest infection rate (11.11%) in Rh. sanguineus. Conclusion: These findings provide epidemiological evidence for planning control strategies of the disease in the study area. PMID:27308296
Directory of Open Access Journals (Sweden)
Maria Mohammadian
2016-01-01
Full Text Available Background: Crimean-Congo Hemorrhagic Fever (CCHF is a feverous and hemorrhagic disease endemic in some parts of Iran and caused by an arbovirus related to Bunyaviridae family and Nairovirusgenus. The main virus reservoir in the nature is ticks, however small vertebrates and a wide range of domestic and wild animals are regarded as reservoir hosts. This study was conducted to determine the infection rate of CCHF virus in hard ticks of Sarpole-Zahab County, Kermanshah province, west of Iran.Methods: From total number of 851 collected ticks from 8 villages, 131 ticks were selected randomlyand investigated for detection of CCHF virus using RT-PCR.Results: The virus was found in 3.8% of the tested ticks. Hyalommaanatolicum, H.asiaticum and Rhipicephalus sanguineus species were found to have viral infection, with the highest infection rate (11.11% in Rh. sanguineus.Conclusion: These findings provide epidemiological evidence for planning control strategies of the disease in the study area.
Kwallah, Allan ole; Inoue, Shingo; Thairu-Muigai, Anne Wangari; Kuttoh, Nancy; Morita, Kouichi; Mwau, Matilu
2015-01-01
Yellow fever (YF), which is caused by a mosquito-borne virus, is an important viral hemorrhagic fever endemic in equatorial Africa and South America. Yellow fever virus (YFV) is the prototype of the family Flaviviridae and genus Flavivirus. The aim of this study was to determine the seroprevalence of YFV in selected health facilities in Western Kenya during the period 2010-2012. A total of 469 serum samples from febrile patients were tested for YFV antibodies using in-house IgM-capture ELISA, in-house indirect IgG ELISA, and 50% focus reduction neutralization test (FRNT50). The present study did not identify any IgM ELISA-positive cases, indicating absence of recent YFV infection in the area. Twenty-eight samples (6%) tested positive for YFV IgG, because of either YFV vaccination or past exposure to various flaviviruses including YFV. Five cases were confirmed by FRNT50; of these, 4 were either vaccination or natural infection during the YF outbreak in 1992-1993 or another period and 1 case was confirmed as a West Nile virus infection. Domestication and routine performance of arboviral differential diagnosis will help to address the phenomenon of pyrexia of unknown origin, contribute to arboviral research in developing countries, and enhance regular surveillance.
Albarnaz, Jonas D; De Oliveira, Leonardo C; Torres, Alice A; Palhares, Rafael M; Casteluber, Marisa C; Rodrigues, Claudiney M; Cardozo, Pablo L; De Souza, Aryádina M R; Pacca, Carolina C; Ferreira, Paulo C P; Kroon, Erna G; Nogueira, Maurício L; Bonjardim, Cláudio A
2014-11-01
Exploiting the inhibition of host signaling pathways aiming for discovery of potential antiflaviviral compounds is clearly a beneficial strategy for the control of life-threatening diseases caused by flaviviruses. Here we describe the antiviral activity of the MEK1/2 inhibitor U0126 against Yellow fever virus 17D vaccine strain (YFV-17D). Infection of VERO cells with YFV-17D stimulates ERK1/2 phosphorylation early during infection. Pharmacological inhibition of MEK1/2 through U0126 treatment of VERO cells blockades not only the YFV-stimulated ERK1/2 phosphorylation, but also inhibits YFV replication by ∼99%. U0126 was also effective against dengue virus (DENV-2 and -3) and Saint-Louis encephalitis virus (SLEV). Levels of NS4AB, as detected by immunofluorescence, are diminished upon treatment with the inhibitor, as well as the characteristic endoplasmic reticulum membrane invagination stimulated during the infection. Though not protective, treatment of YFV-infected, adult BALB/c mice with U0126 resulted in significant reduction of virus titers in brains. Collectively, our data suggest the potential targeting of the MEK1/2 kinase as a therapeutic tool against diseases caused by flaviviruses such as yellow fever, adverse events associated with yellow fever vaccination and dengue. Copyright © 2014 Elsevier B.V. All rights reserved.
The Incidence and Management of Typhoid Fever in Nigeria ...
African Journals Online (AJOL)
Typhoid or enteric fever is caused by Salmonella typhi. It is largely a disease of developing nations due to their poor standard of hygiene and ... Symptoms such as diarrhoea, constipation, abdominal pain and encephalopathy may occur. Complications like intestinal perforation and gastrointestinal haemorrhage may occur ...
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
Crimean-Congo Hemorrhagic Fever: Tick-Host-Virus Interactions
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Anna Papa
2017-05-01
Full Text Available Crimean-Congo hemorrhagic fever virus (CCHFV is transmitted to humans by bite of infected ticks or by direct contact with blood or tissues of viremic patients or animals. It causes to humans a severe disease with fatality up to 30%. The current knowledge about the vector-host-CCHFV interactions is very limited due to the high-level containment required for CCHFV studies. Among ticks, Hyalomma spp. are considered the most competent virus vectors. CCHFV evades the tick immune response, and following its replication in the lining of the tick's midgut, it is disseminated by the hemolymph in the salivary glands and reproductive organs. The introduction of salivary gland secretions into the host cells is the major route via which CCHFV enters the host. Following an initial amplification at the site of inoculation, the virus is spread to the target organs. Apoptosis is induced via both intrinsic and extrinsic pathways. Genetic factors and immune status of the host may affect the release of cytokines which play a major role in disease progression and outcome. It is expected that the use of new technology of metabolomics, transcriptomics and proteomics will lead to improved understanding of CCHFV-host interactions and identify potential targets for blocking the CCHFV transmission.
International Nuclear Information System (INIS)
Hernaez, Bruno; Escribano, Jose M.; Alonso, Covadonga
2006-01-01
Many stages of African swine fever virus infection have not yet been studied in detail. To track the behavior of African swine fever virus (ASFV) in the infected cells in real time, we produced an infectious recombinant ASFV (B54GFP-2) that expresses and incorporates into the virus particle a chimera of the p54 envelope protein fused to the enhanced green fluorescent protein (EGFP). The incorporation of the fusion protein into the virus particle was confirmed immunologically and it was determined that p54-EGFP was fully functional by confirmation that the recombinant virus made normal-sized plaques and presented similar growth curves to the wild-type virus. The tagged virus was visualized as individual fluorescent particles during the first stages of infection and allowed to visualize the infection progression in living cells through the viral life cycle by confocal microscopy. In this work, diverse potential applications of B54GFP-2 to study different aspects of ASFV infection are shown. By using this recombinant virus it was possible to determine the trajectory and speed of intracellular virus movement. Additionally, we have been able to visualize for first time the ASFV factory formation dynamics and the cytophatic effect of the virus in live infected cells. Finally, we have analyzed virus progression along the infection cycle and infected cell death as time-lapse animations
DEFF Research Database (Denmark)
Ito, Takafumi; Olesen, Niels Jørgen
2013-01-01
Genotype IVb of viral haemorrhagic septicaemia virus (VHSV) was isolated for the first time in the Great Lakes basin in 2003, where it spread and caused mass mortalities in several wild fish species throughout the basin. In order to prevent further spreading of the disease and to assess risks...... mortalities in bluegill Lepomis macrochirus used as positive controls, Japanese fluvial sculpin Cottus pollux, and iwana Salvelinus leucomaenis pluvius were 50, 80 and 0%, respectively. In Expt 2, cumulative mortalities of 100, 100 and 10% were observed in Japanese fluvial sculpin C. pollux, Japanese rice......-isolation by cell culture was successful from all dead fish. We detected the virus in the brain from a few surviving bluegill 50 d post exposure by both cell culture and RT-PCR. These results revealed that VHSV IVb could become a serious threat to wild freshwater fish species in Japan, and that some surviving fish...
Directory of Open Access Journals (Sweden)
Lidia Lasecka
Full Text Available Nairobi sheep disease virus (NSDV; also called Ganjam virus in India is a bunyavirus of the genus Nairovirus. It causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%. The virus is closely related to the human pathogen Crimean-Congo haemorrhagic fever virus (CCHFV. Little is currently known about the biology of NSDV. We have generated specific antibodies against the virus nucleocapsid protein (N and polymerase (L and used these to characterise NSDV in infected cells and to study its distribution during infection in a natural host. Due to its large size and the presence of a papain-like protease (the OTU-like domain it has been suggested that the L protein of nairoviruses undergoes an autoproteolytic cleavage into polymerase and one or more accessory proteins. Specific antibodies which recognise either the N-terminus or the C-terminus of the NSDV L protein showed no evidence of L protein cleavage in NSDV-infected cells. Using the specific anti-N and anti-L antibodies, it was found that these viral proteins do not fully colocalise in infected cells; the N protein accumulated near the Golgi at early stages of infection while the L protein was distributed throughout the cytoplasm, further supporting the multifunctional nature of the L protein. These antibodies also allowed us to gain information about the organs and cell types targeted by the virus in vivo. We could detect NSDV in cryosections prepared from various tissues collected post-mortem from experimentally inoculated animals; the virus was found in the mucosal lining of the small and large intestine, in the lungs, and in mesenteric lymph nodes (MLN, where NSDV appeared to target monocytes and/or macrophages.
Transboundary animal disease viruses such as foot-and-mouth disease virus (FMDV) and African swine fever virus (ASFV) are highly contagious and cause severe morbidity and mortality in livestock. Proper disinfection during an outbreak can help prevent virus spread and will shorten the time for contam...
Astuti Thamrin, Sri; Taufik, Irfan
2018-03-01
Dengue haemorrhagic fever (DHF) is an infectious disease caused by dengue virus. The increasing number of people with DHF disease correlates with the neighbourhood, for example sub-districts, and the characteristics of the sub-districts are formed from individuals who are domiciled in the sub-districts. Data containing individuals and sub-districts is a hierarchical data structure, called multilevel analysis. Frequently encountered response variable of the data is the time until an event occurs. Multilevel and spatial models are being increasingly used to obtain substantive information on area-level inequalities in DHF survival. Using a case study approach, we report on the implications of using multilevel with spatial survival models to study geographical inequalities in all cause survival.
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
Yellow Fever Vaccine: What You Need to Know
... How can I prevent yellow fever? Yellow fever vaccine Yellow fever vaccine can prevent yellow fever. Yellow fever vaccine ... such as those containing DEET. 3 Yellow fever vaccine Yellow fever vaccine is a live, weakened virus. It is ...
Lima, Maura Antonia; Romano-Lieber, Nicolina Silvana; Duarte, Ana Maria Ribeiro de Castro
2010-01-01
Yellow fever (YF) is an acute viral infectious disease transmitted by mosquitoes which occurs in two distinct epidemiological cycles: sylvatic and urban. In the sylvatic cycle, the virus is maintained by monkey's infection and transovarian transmission in vectors. Surveillance of non-human primates is required for the detection of viral circulation during epizootics, and for the identification of unaffected or transition areas. An ELISA (enzyme-linked immunosorbent assay) was standardized for estimation of the prevalence of IgG antibodies against yellow fever virus in monkey sera (Alouatta caraya) from the reservoir area of Porto Primavera Hydroelectric Plant, in the state of São Paulo, Brazil. A total of 570 monkey sera samples were tested and none was reactive to antibodies against yellow fever virus. The results corroborate the epidemiology of yellow fever in the area. Even though it is considered a transition area, there were no reports to date of epizootics or yellow fever outbreaks in humans. Also, entomological investigations did not detect the presence of vectors of this arbovirus infection. ELISA proved to be fast, sensitive, an adequate assay, and an instrument for active search in the epidemiological surveillance of yellow fever allowing the implementation of prevention actions, even before the occurrence of epizootics.
Management of a Lassa fever outbreak, Rhineland-Palatinate, Germany, 2016.
Ehlkes, Lutz; George, Maja; Samosny, Gerhard; Burckhardt, Florian; Vogt, Manfred; Bent, Stefan; Jahn, Klaus; Zanger, Philipp
2017-09-01
Due to rapid diagnosis and isolation of imported cases, community outbreaks of viral haemorrhagic fevers (VHF) are considered unlikely in industrialised countries. In March 2016, the first documented locally acquired case of Lassa fever (LF) outside Africa occurred, demonstrating the disease's potential as a cross-border health threat. We describe the management surrounding this case of LF in Rhineland-Palatinate - the German federal state where secondary transmission occurred. Twelve days after having been exposed to the corpse of a LF case imported from Togo, a symptomatic undertaker tested positive for Lassa virus RNA. Potential contacts were traced, categorised based on exposure risk, and monitored. Overall, we identified 21 contact persons with legal residency in Rhineland-Palatinate: seven related to the index case, 13 to the secondary case, and one related to both. The secondary case received treatment and recovered. Five contacts were quarantined and one was temporarily banned from work. No further transmission occurred. Based on the experience gained during the outbreak and a review of national and international guidelines, we conclude that exposure risk attributable to corpses may currently be underestimated, and we present suggestions that may help to improve the anti-epidemic response to imported VHF cases in industrialised countries.
Live Zika virus chimeric vaccine candidate based on a yellow fever 17-D attenuated backbone
Nougairede, Antoine; Klitting, Raphaelle; Aubry, Fabien; Gilles, Magali; Touret, Franck; De Lamballerie, Xavier
2018-01-01
Zika virus (ZIKV) recently dispersed throughout the tropics and sub-tropics causing epidemics associated with congenital disease and neurological complications. There is currently no commercial vaccine for ZIKV. Here we describe the initial development of a chimeric virus containing the prM/E proteins of a ZIKV epidemic strain incorporated into a yellow fever 17-D attenuated backbone. Using the versatile and rapid ISA (Infectious Subgenomic Amplicons) reverse genetics method, we compared diff...
Antibodies against Severe Fever with Thrombocytopenia Syndrome Virus in Healthy Persons, China, 2013
Zhang, Lei; Sun, Jimin; Yan, Jie; Lv, Huakun; Chai, Chengliang; Sun, Yi; Shao, Bin; Jiang, Jianmin; Chen, Zhiping
2014-01-01
In June 2013, a subclinical infection with severe fever with thrombocytopenia syndrome virus (SFTSV) was detected in Zhejiang Province, China, prompting seroprevalence studies in 6 districts within the province. Of 986 healthy persons tested, 71 had IgG antibodies against SFTSV. This finding suggests that most natural infections with SFTSV are mild or subclinical. PMID:25061813
Lovrić, Z; Kolarić, B; Kosanović Ličina, M L; Tomljenović, M; Đaković Rode, O; Danis, K; Kaić, B; Tešić, V
2018-05-16
In 2017 Zagreb faced the largest outbreak of haemorrhagic fever with renal syndrome (HFRS) to date. We investigated to describe the extent of the outbreak and identify risk factors for infection. We compared laboratory-confirmed cases of Hantavirus infection in Zagreb residents with the onset of illness after 1 January 2017, with individually matched controls from the same household or neighbourhood. We calculated adjusted matched odds ratios (amOR) using conditional logistic regression. During 2017, 104 cases were reported: 11-81 years old (median 37) and 71% (73) male. Compared with 104 controls, cases were more likely to report visiting Mount Medvednica (amOR 60, 95% CI 6-597), visiting a forest (amOR 46, 95% CI 4.7-450) and observing rodents (amOR 20, 95% CI 2.6-159). Seventy per cent of cases (73/104) had visited Mount Medvednica prior to infection. Among participants who had visited Mount Medvednica, cases were more likely to have drunk water from a spring (amOR 22, 95% CI 1.9-265), observed rodents (amOR 17, 95% CI 2-144), picked flowers (amOR 15, 95% CI 1.2-182) or cycled (amOR 14, 95% CI 1.6-135). Our study indicated that recreational activity around Mount Medvednica was associated with HFRS. We recommend enhanced surveillance of the recreational areas during an outbreak.
Molinas, Andrea; Mirazimi, Ali; Holm, Angelika; Loitto, Vesa M; Magnusson, Karl-Eric; Vikström, Elena
2016-04-01
Crimean-Congo hemorrhagic fever virus (CCHFV) is an arthropod-borne pathogen that causes infectious disease with severe hemorrhagic manifestations in vascular system in humans. The proper function of the cells in the vascular system is critically regulated by aquaporins (AQP), water channels that facilitate fluxes of water and small solutes across membranes. With Hazara virus as a model for CCHFV, we investigated the effects of viruses on AQP6 and the impact of AQP6 on virus infectivity in host cells, using transiently expressed GFP-AQP6 cells, immunofluorescent assay for virus detection, epifluorescent imaging of living cells and confocal microscopy. In GFP-AQP6 expressing cells, Hazara virus reduced both the cellular and perinuclear AQP6 distribution and changed the cell area. Infection of human cell with CCHFV strain IbAR 10200 downregulated AQP6 expression at mRNA level. Interestingly, the overexpression of AQP6 in host cells decreased the infectivity of Hazara virus, speaking for a protective role of AQP6. We suggest the possibility for AQP6 being a novel player in the virus-host interactions, which may lead to less severe outcomes of an infection. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
Viral haemorrhagic septicaemia virus in marine fish and its implications for fish farming - a review
DEFF Research Database (Denmark)
Skall, Helle Frank; Olesen, Niels Jørgen; Mellergaard, Stig
2005-01-01
Viral haemorrhagic septicaemia virus (VHSV) has, in recent decades, been isolated from an increasing number of free-living marine fish species. So far, it has been isolated from at least 48 fish species from the northern hemisphere, including North America, Asia and Europe, and fifteen different...... marine fish show no to low pathogenicity to rainbow trout and Atlantic salmon, although several are pathogenic for turbot. Marine VHSV isolates are so far serologically indistinguishable from freshwater isolates. Genotyping based on VHSV G- and N-genes reveals four groups indicating the geographical...... origin of the isolates, with one group representing traditional European freshwater isolates and isolates of north European marine origin, a second group of marine isolates from the Baltic Sea, a third group of isolates from the North Sea, and a group representing North American isolates. Examples...
Guven et al., Afr., J. Infect. Dis.
African Journals Online (AJOL)
Ticks are the most important, blood-feeding arthropod vectors that carry zoonotic disease agents to humans. ... (CCHF) is an acute and severe hemorrhagic fever syndrome, caused by Nairovirus of the Bunyaviridae family, ... The CCHF virus causes severe viral haemorrhagic fever outbreaks, with a case fatality rate of 3–.
Oral receptivity of Aedes aegypti from Cape Verde for yellow fever, dengue, and chikungunya viruses.
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.
Spatio-Temporal modelling of Dengue Fever in Zulia state, Venezuela
Cabrera, Maritza
2014-01-01
Over half of the world's population are at risk of infection from dengue fever (Guha-Sapir2005). This viral disease is transmitted by the female Aedes aegypti mosquito and is the major source of human death in the world when compared with any other vector borne disease (Gubler1998a). The first important epidemic of dengue haemorrhagic fever (DHF) in America was reported in Cuba in 1981 and subsequently in Venezuela during 1989 and 1990 (Oletta2006, Brightmer1998). There has been a trend of in...
Propagation of classical swine fever virus in vitro circumventing heparan sulfate-adaptation.
Eymann-Häni, Rita; Leifer, Immanuel; McCullough, Kenneth C; Summerfield, Artur; Ruggli, Nicolas
2011-09-01
Amplification of natural virus isolates in permanent cell lines can result in adaptation, in particular enhanced binding to heparan sulfate (HS)-containing glycosaminoglycans present on most vertebrate cells. This has been reported for several viruses, including the pestivirus classical swine fever virus (CSFV), the causative agent of a highly contagious hemorrhagic disease in pigs. Propagation of CSFV in cell culture is essential in virus diagnostics and research. Adaptation of CSFV to HS-binding has been related to amino acid changes in the viral E(rns) glycoprotein, resulting in viruses with altered replication characteristics in vitro and in vivo. Consequently, a compound blocking the HS-containing structures on cell surfaces was employed to monitor conversion from HS-independency to HS-dependency. It was shown that the porcine PEDSV.15 cell line permitted propagation of CSFV within a limited number of passages without adaptation to HS-binding. The selection of HS-dependent CSFV mutants was also prevented by propagation of the virus in the presence of DSTP 27. The importance of these findings can be seen from the altered ratio of cell-associated to secreted virus upon acquisition of enhanced HS-binding affinity, a phenotype proposed previously to be related to virulence in the natural host. Copyright © 2011 Elsevier B.V. All rights reserved.
Lumley, Sarah; Horton, Daniel L; Hernandez-Triana, Luis L M; Johnson, Nicholas; Fooks, Anthony R; Hewson, Roger
2017-05-01
Rift Valley fever virus (RVFV) is a mosquito-borne arbovirus causing severe disease in humans and ruminants. Spread of RVFV out of Africa has raised concerns that it could emerge in Europe or the USA. Virus persistence is dependent on successful infection of, replication in, and transmission to susceptible vertebrate and invertebrate hosts, modulated by virus-host and vector-virus interactions. The principal accepted theory for the long-term maintenance of RVFV involves vertical transmission (VT) of virus to mosquito progeny, with the virus surviving long inter-epizootic periods within the egg. This VT hypothesis, however, is yet to be comprehensively proven. Here, evidence for and against the VT of RVFV is reviewed along with the identification of factors limiting its detection in natural and experimental data. The observations of VT for other arboviruses in the genera Alphavirus, Flavivirus and Orthobunyavirus are discussed within the context of RVFV. The review concludes that VT of RVFV is likely but that current data are insufficient to irrefutably prove this hypothesis.
Approaches and Perspectives for Development of African Swine Fever Virus Vaccines
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Marisa Arias
2017-10-01
Full Text Available African swine fever (ASF is a complex disease of swine, caused by a large DNA virus belonging to the family Asfarviridae. The disease shows variable clinical signs, with high case fatality rates, up to 100%, in the acute forms. ASF is currently present in Africa and Europe where it circulates in different scenarios causing a high socio-economic impact. In most affected regions, control has not been effective in part due to lack of a vaccine. The availability of an effective and safe ASFV vaccines would support and enforce control–eradication strategies. Therefore, work leading to the rational development of protective ASF vaccines is a high priority. Several factors have hindered vaccine development, including the complexity of the ASF virus particle and the large number of proteins encoded by its genome. Many of these virus proteins inhibit the host’s immune system thus facilitating virus replication and persistence. We review previous work aimed at understanding ASFV–host interactions, including mechanisms of protective immunity, and approaches for vaccine development. These include live attenuated vaccines, and “subunit” vaccines, based on DNA, proteins, or virus vectors. In the shorter to medium term, live attenuated vaccines are the most promising and best positioned candidates. Gaps and future research directions are evaluated.
Dengue fever: a Wikipedia clinical review.
Heilman, James M; De Wolff, Jacob; Beards, Graham M; Basden, Brian J
2014-01-01
Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treatment of acute dengue fever is supportive, with either oral or intravenous rehydration for mild or moderate disease and use of intravenous fluids and blood transfusion for more severe cases. Along with attempts to eliminate the mosquito vector, work is ongoing to develop a vaccine and medications targeted directly at the virus.
Tretyakova, Irina; Nickols, Brian; Hidajat, Rachmat; Jokinen, Jenny; Lukashevich, Igor S; Pushko, Peter
2014-11-01
Yellow fever (YF) causes an acute hemorrhagic fever disease in tropical Africa and Latin America. To develop a novel experimental YF vaccine, we applied iDNA infectious clone technology. The iDNA represents plasmid that encodes the full-length RNA genome of 17D vaccine downstream from a cytomegalovirus (CMV) promoter. The vaccine was designed to transcribe the full-length viral RNA and to launch 17D vaccine virus in vitro and in vivo. Transfection with 10 ng of iDNA plasmid was sufficient to start replication of vaccine virus in vitro. Safety of the parental 17D and iDNA-derived 17D viruses was confirmed in AG129 mice deficient in receptors for IFN-α/β/γ. Finally, direct vaccination of BALB/c mice with a single 20 μg dose of iDNA plasmid resulted in seroconversion and elicitation of virus-specific neutralizing antibodies in animals. We conclude that iDNA immunization approach combines characteristics of DNA and attenuated vaccines and represents a promising vaccination strategy for YF. Copyright © 2014 Elsevier Inc. All rights reserved.
Need yellow fever vaccine? Plan ahead
... Submit What's this? Submit Button Past Emails Need yellow fever vaccine? Plan ahead. Language: English (US) Español (Spanish) ... none were from the United States). What is yellow fever? Yellow fever is caused by a virus that ...
Environmental temperature has been shown to affect the ability of mosquitoes to transmit numerous arboviruses and for Rift Valley fever virus (RVFV) in particular. We evaluated the effect of incubation temperatures ranging from 14-26ºC on infection, dissemination, and transmission rates for Culex ta...
FEVER AS INDICATOR TO SECONDARY INFECTION IN DENGUE VIRAL INFECTION
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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
Phylogeny of Yellow Fever Virus, Uganda, 2016.
Hughes, Holly R; Kayiwa, John; Mossel, Eric C; Lutwama, Julius; Staples, J Erin; Lambert, Amy J
2018-08-17
In April 2016, a yellow fever outbreak was detected in Uganda. Removal of contaminating ribosomal RNA in a clinical sample improved the sensitivity of next-generation sequencing. Molecular analyses determined the Uganda yellow fever outbreak was distinct from the concurrent yellow fever outbreak in Angola, improving our understanding of yellow fever epidemiology.
Vela, Eric M; Knostman, Katherine A; Mott, Jason M; Warren, Richard L; Garver, Jennifer N; Vela, Lela Johnson; Stammen, Rachelle L
2010-09-01
Arenaviruses are rodent-borne negative strand RNA viruses and infection of these viruses in humans may result in disease and hemorrhagic fever. To date, supportive care, ribavirin, and in some cases immune plasma remain the foremost treatment options for arenaviral hemorrhagic fever. Research with the hemorrhagic fever causing-arenaviruses usually requires a Biosafety level (BSL)-4 environment; however, surrogate animal model systems have been developed to preliminarily study and screen various vaccines and antivirals. The Syrian golden hamster-Pirital virus (PIRV) surrogate model of hemorrhagic fever provides an opportunity to test new antivirals in an ABSL-3 setting. Thus, we challenged hamsters, implanted with telemetry, with PIRV and observed viremia and tissue viral titers, and changes in core body temperature, hematology, clinical chemistry, and coagulation parameters. Physical signs of disease of the PIRV-infected hamsters included weight loss, lethargy, petechial rashes, epistaxis, ocular orbital and rectal hemorrhage, and visible signs of neurologic disorders. However, treating animals with genistein, a plant derived isoflavone and general kinase inhibitor, resulted in increased survival rates and led to an improved clinical profile. In all, the results from this study demonstrate the potential of a general kinase inhibitor genistein as an antiviral against arenaviral hemorrhagic fever. 2010 Elsevier B.V. All rights reserved.
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
Guo, Fang; Wu, Shuo; Julander, Justin; Ma, Julia; Zhang, Xuexiang; Kulp, John; Cuconati, Andrea; Block, Timothy M; Du, Yanming; Guo, Ju-Tao; Chang, Jinhong
2016-09-21
Although a highly effective vaccine is available, the number of yellow fever cases has increased over the past two decades, which highlights the pressing need for antiviral therapeutics. In a high throughput screening campaign, we identified an acetic acid benzodiazepine (BDAA) compound, which potently inhibits yellow fever virus (YFV). Interestingly, while treatment of YFV infected cultures with 2 μM of BDAA reduced the virion production by greater than 2 logs, the compound is not active against 21 other viruses from 14 different viral families. Selection and genetic analysis of drug resistant viruses revealed that substitution of proline at amino acid 219 (P219) of the nonstructural protein 4B (NS4B) with serine, threonine or alanine confers YFV resistance to BDAA without apparent loss of replication fitness in cultured mammalian cells. However, substitution of P219 with glycine confers BDAA resistance with significant loss of replication ability. Bioinformatics analysis predicts that the P219 localizes at the endoplasmic reticulum lumen side of the fifth putative trans-membrane domain of NS4B and the mutation may render the viral protein incapable of interacting with BDAA. Our studies thus revealed important role and structural basis for NS4B protein in supporting YFV replication. Moreover, in YFV-infected hamsters, oral administration of BDAA protected 90% of the animals from death, significantly reduced viral load by greater than 2 logs and attenuated viral infection-induced liver injury and body weight loss. The encouraging preclinical results thus warrant further development of BDAA or its derivatives as antiviral agents to treat yellow fever. Yellow fever is an acute viral hemorrhagic disease which threatens approximately one billion people living in tropical areas of Africa and Latin America. Although a highly effective yellow fever vaccine has been available for more than seven decades, the low vaccination rate fails to prevent outbreaks in at
Jancovich, James K; Chapman, Dave; Hansen, Debra T; Robida, Mark D; Loskutov, Andrey; Craciunescu, Felicia; Borovkov, Alex; Kibler, Karen; Goatley, Lynnette; King, Katherine; Netherton, Christopher L; Taylor, Geraldine; Jacobs, Bertram; Sykes, Kathryn; Dixon, Linda K
2018-04-15
African swine fever virus (ASFV) causes an acute hemorrhagic fever in domestic pigs, with high socioeconomic impact. No vaccine is available, limiting options for control. Although live attenuated ASFV can induce up to 100% protection against lethal challenge, little is known of the antigens which induce this protective response. To identify additional ASFV immunogenic and potentially protective antigens, we cloned 47 viral genes in individual plasmids for gene vaccination and in recombinant vaccinia viruses. These antigens were selected to include proteins with different functions and timing of expression. Pools of up to 22 antigens were delivered by DNA prime and recombinant vaccinia virus boost to groups of pigs. Responses of immune lymphocytes from pigs to individual recombinant proteins and to ASFV were measured by interferon gamma enzyme-linked immunosorbent spot (ELISpot) assays to identify a subset of the antigens that consistently induced the highest responses. All 47 antigens were then delivered to pigs by DNA prime and recombinant vaccinia virus boost, and pigs were challenged with a lethal dose of ASFV isolate Georgia 2007/1. Although pigs developed clinical and pathological signs consistent with acute ASFV, viral genome levels were significantly reduced in blood and several lymph tissues in those pigs immunized with vectors expressing ASFV antigens compared with the levels in control pigs. IMPORTANCE The lack of a vaccine limits the options to control African swine fever. Advances have been made in the development of genetically modified live attenuated ASFV that can induce protection against challenge. However, there may be safety issues relating to the use of these in the field. There is little information about ASFV antigens that can induce a protective immune response against challenge. We carried out a large screen of 30% of ASFV antigens by delivering individual genes in different pools to pigs by DNA immunization prime and recombinant vaccinia
Treating viral hemorrhagic fever.
Mairuhu, A.T.; Brandjes, D.P.; Gorp, E. van
2003-01-01
Viral hemorrhagic fevers are illnesses associated with a number of geographically restricted, mostly tropical areas. Over recent decades a number of new hemorrhagic fever viruses have emerged. Advances in our understanding of the pathophysiology of these diseases have improved our initial supportive
[Neonatal subgaleal haemorrhage; a potential life-threatening extracranial haemorrhage
Fuijkschot, J.; Antonius, T.A.J.; Meijers, P.W.; Vrancken, S.L.A.G.
2008-01-01
A female neonate delivered at term developed hypovolemic shock due to a subgaleal haemorrhage, i.e. extracranial bleeding between the galea aponeurotica and the cranial periosteum. The subgaleal haemorrhage was most likely the result of a traumatic vacuum extraction. The patient was treated with
International Nuclear Information System (INIS)
Shustov, Alexandr V.; Frolov, Ilya
2010-01-01
In our previous studies, we have stated to build a new strategy for developing defective, pseudoinfectious flaviviruses (PIVs) and applying them as a new type of vaccine candidates. PIVs combined the efficiency of live vaccines with the safety of inactivated or subunit vaccines. The results of the present work demonstrate further development of chimeric PIVs encoding dengue virus 2 (DEN2V) glycoproteins and yellow fever virus (YFV)-derived replicative machinery as potential vaccine candidates. The newly designed PIVs have synergistically functioning mutations in the prM and NS2A proteins, which abolish processing of the latter proteins and make the defective viruses capable of producing either only noninfectious, immature and/or subviral DEN2V particles. The PIV genomes can be packaged to high titers into infectious virions in vitro using the NS1-deficient YFV helper RNAs, and both PIVs and helpers can then be passaged as two-component genome viruses at an escalating scale.
Restriction of Rift Valley Fever Virus Virulence in Mosquito Cells
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Sonja R. Gerrard
2010-02-01
Full Text Available Arboviruses are maintained in a natural cycle that requires blood-sucking arthropod and vertebrate hosts. Arboviruses are believed to persistently infect their arthropod host without overt pathology and cause acute infection with viremia in their vertebrate host. We have focused on elucidating how a specific arbovirus, Rift Valley fever (RVF virus, causes cytopathic effect in cells derived from vertebrates and non-cytopathic infection in cells derived from arthropods. We demonstrate that the vertebrate virulence factor, NSs, is functional in arthropod cells but is expressed at significantly lower levels in infected arthropod versus infected vertebrate cells.
Goller, Katja V; Gabriel, Claudia; Dimna, Mireille Le; Le Potier, Marie-Frédérique; Rossi, Sophie; Staubach, Christoph; Merboth, Matthias; Beer, Martin; Blome, Sandra
2016-03-01
Classical swine fever is a viral disease of pigs that carries tremendous socio-economic impact. In outbreak situations, genetic typing is carried out for the purpose of molecular epidemiology in both domestic pigs and wild boar. These analyses are usually based on harmonized partial sequences. However, for high-resolution analyses towards the understanding of genetic variability and virus evolution, full-genome sequences are more appropriate. In this study, a unique set of representative virus strains was investigated that was collected during an outbreak in French free-ranging wild boar in the Vosges-du-Nord mountains between 2003 and 2007. Comparative sequence and evolutionary analyses of the nearly full-length sequences showed only slow evolution of classical swine fever virus strains over the years and no impact of vaccination on mutation rates. However, substitution rates varied amongst protein genes; furthermore, a spatial and temporal pattern could be observed whereby two separate clusters were formed that coincided with physical barriers.
Morphological studies in a model for dengue-2 virus infection in mice
Directory of Open Access Journals (Sweden)
Ortrud Monika Barth
2006-12-01
Full Text Available One of the main difficulties in studying dengue virus infection in humans and in developing a vaccine is the absence of a suitable animal model which develops the full spectrum of dengue fever, dengue haemorrhagic fever, and dengue shock syndrome. It is our proposal to present morphological aspects of an animal model which shows many similarities with the dengue infection in humans. BALB/c mice were intraperitoneally infected with non-neuroadapted dengue virus serotype 2 (DENV-2. Histopathological and morphometrical analyses of liver tissue revealed focal alterations along the infection, reaching wide-ranging portal and centrolobular veins congestion and sinusoidal cell death. Additional ultrastructural observations demonstrated multifocal endothelial injury, platelet recruitment, and alterated hepatocytes. Dengue virus antigen was detected in hepatocytes and in the capillar endothelium of the central lobular vein area. Liver function tests showed high levels of aspartate transaminase and alanine transaminase enzyme activity. Lung tissue showed interstitial pneumonia and mononuclear cells, interseptal oedema, hyperplasia, and hypertrophy of the bronchiolar epithelial cells. DENV-2 led to a transient inflammatory process, but caused focal alterations of the blood-exchange barrier. Viremia was observed from 2nd to 11th day p.i. by isolation of DENV-2 in C6/36 mosquito cell line inoculated with the supernatant of macerated liver, lung, kidney, and cerebellum tissues of the infected mice.
Spatio-temporal risk factors for viral haemorrhagic septicaemia (VHS) in Danish aquaculture
DEFF Research Database (Denmark)
Jensen, Ann Britt Bang; Ersbøll, Annette Kjær; Korsholm, Henrik
2014-01-01
Viral haemorrhagic septicaemia (VHS) is an economically very important fish disease in the northern hemisphere. When the VHS virus was first isolated in Denmark 50 yr ago, more than 80% of the 800 Danish fish farms were considered to be infected, but vigilant surveillance and eradication programmes...
Animal Models of Tick-Borne Hemorrhagic Fever Viruses
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Heinz Feldmann
2013-05-01
Full Text Available Tick-borne hemorrhagic fever viruses (TBHFV are detected throughout the African and Eurasian continents and are an emerging or re-emerging threat to many nations. Due to the largely sporadic incidences of these severe diseases, information on human cases and research activities in general have been limited. In the past decade, however, novel TBHFVs have emerged and areas of endemicity have expanded. Therefore, the development of countermeasures is of utmost importance in combating TBHFV as elimination of vectors and interrupting enzootic cycles is all but impossible and ecologically questionable. As in vivo models are the only way to test efficacy and safety of countermeasures, understanding of the available animal models and the development and refinement of animal models is critical in negating the detrimental impact of TBHFVs on public and animal health.
Directory of Open Access Journals (Sweden)
Charlotte E. Ellis
2014-05-01
Full Text Available Rift Valley fever virus (RVFV infects humans and livestock, causing haemorrhaging andabortions in animals. Three major RVF epizootics have occurred in South Africa since the1950s and the outbreak in 2010 had a mortality rate of 10.7% in humans. Accurate and earlydetection is therefore essential for management of this zoonotic disease. Enzyme-linkedimmunosorbent assays (ELISAs have been developed for the detection of either IgM or IgGantibodies to RVFV in animal sera. In this study, data are presented on the validation of adouble-antigen ELISA for the simultaneous detection of both classes of antibodies to RVFV ina single test. ELISA plates were coated with a recombinant nucleoprotein. The nucleoprotein,conjugated to horseradish peroxidase, was used as the detecting reagent. A total of 534 serafrom sheep and cattle were used in the validation. The sheep sera were collected during a RVFpathogenesis study at the Agricultural Research Council (ARC – Onderstepoort VeterinaryInstitute and the cattle sera were collected during an outbreak of RVF in 2008 at the ARC –Animal Production Institute in Irene, Pretoria. The ELISA had a diagnostic sensitivity of 98.4%and a specificity of 100% when compared to a commercial cELISA. This convenient and fastassay is suitable for use in serological surveys or monitoring immune responses in vaccinatedanimals.
Directory of Open Access Journals (Sweden)
Fadila Amraoui
Full Text Available West Nile fever (WNF and Rift Valley fever (RVF are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 10(7.8 and 10(8.5 plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14-21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology.
Ebola virus and Marburg virus Overview Ebola virus and Marburg virus are related viruses that cause hemorrhagic fevers — illnesses marked by severe bleeding (hemorrhage), organ failure and, in many ...
Makiala-Mandanda, Sheila; Le Gal, Frédéric; Ngwaka-Matsung, Nadine; Ahuka-Mundeke, Steve; Onanga, Richard; Bivigou-Mboumba, Berthold; Pukuta-Simbu, Elisabeth; Gerber, Athenaïs; Abbate, Jessica L; Mwamba, Dieudonné; Berthet, Nicolas; Leroy, Eric Maurice; Muyembe-Tamfum, Jean-Jacques; Becquart, Pierre
2017-05-01
The majority of patients with acute febrile jaundice (>95%) identified through a yellow fever surveillance program in the Democratic Republic of Congo (DRC) test negative for antibodies against yellow fever virus. However, no etiological investigation has ever been carried out on these patients. Here, we tested for hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), and hepatitis E (HEV) viruses, all of which can cause acute febrile jaundice, in patients included in the yellow fever surveillance program in the DRC. On a total of 498 serum samples collected from suspected cases of yellow fever from January 2003 to January 2012, enzyme-linked immunosorbent assay (ELISA) techniques were used to screen for antibodies against HAV (IgM) and HEV (IgM) and for antigens and antibodies against HBV (HBsAg and anti-hepatitis B core protein [HBc] IgM, respectively), HCV, and HDV. Viral loads and genotypes were determined for HBV and HVD. Viral hepatitis serological markers were diagnosed in 218 (43.7%) patients. The seroprevalences were 16.7% for HAV, 24.6% for HBV, 2.3% for HCV, and 10.4% for HEV, and 26.1% of HBV-positive patients were also infected with HDV. Median viral loads were 4.19 × 10 5 IU/ml for HBV (range, 769 to 9.82 × 10 9 IU/ml) and 1.4 × 10 6 IU/ml for HDV (range, 3.1 × 10 2 to 2.9 × 10 8 IU/ml). Genotypes A, E, and D of HBV and genotype 1 of HDV were detected. These high hepatitis prevalence rates highlight the necessity to include screening for hepatitis viruses in the yellow fever surveillance program in the DRC. Copyright © 2017 Makiala-Mandanda et al.
Functional requirements of the yellow fever virus capsid protein.
Patkar, Chinmay G; Jones, Christopher T; Chang, Yu-hsuan; Warrier, Ranjit; Kuhn, Richard J
2007-06-01
Although it is known that the flavivirus capsid protein is essential for genome packaging and formation of infectious particles, the minimal requirements of the dimeric capsid protein for virus assembly/disassembly have not been characterized. By use of a trans-packaging system that involved packaging a yellow fever virus (YFV) replicon into pseudo-infectious particles by supplying the YFV structural proteins using a Sindbis virus helper construct, the functional elements within the YFV capsid protein (YFC) were characterized. Various N- and C-terminal truncations, internal deletions, and point mutations of YFC were analyzed for their ability to package the YFV replicon. Consistent with previous reports on the tick-borne encephalitis virus capsid protein, YFC demonstrates remarkable functional flexibility. Nearly 40 residues of YFC could be removed from the N terminus while the ability to package replicon RNA was retained. Additionally, YFC containing a deletion of approximately 27 residues of the C terminus, including a complete deletion of C-terminal helix 4, was functional. Internal deletions encompassing the internal hydrophobic sequence in YFC were, in general, tolerated to a lesser extent. Site-directed mutagenesis of helix 4 residues predicted to be involved in intermonomeric interactions were also analyzed, and although single mutations did not affect packaging, a YFC with the double mutation of leucine 81 and valine 88 was nonfunctional. The effects of mutations in YFC on the viability of YFV infection were also analyzed, and these results were similar to those obtained using the replicon packaging system, thus underscoring the flexibility of YFC with respect to the requirements for its functioning.
DEFF Research Database (Denmark)
Hadsbjerg, Johanne; Friis, Martin Barfred; Fahnøe, Ulrik
2016-01-01
RNA could be detected. However, the animals inoculated with these mutant viruses seroconverted against CSFV. Thus, these mutant viruses were highly attenuated in vivo. All 4 rescued viruses were also passaged up to 20 times in cell culture. Using full genome sequencing, the same two adaptations within......Classical swine fever virus (CSFV) causes an economically important disease of swine. Four different viruses were rescued from full-length cloned cDNAs derived from the Paderborn strain of CSFV. Three of these viruses had been modified by mutagenesis (with 7 or 8 nt changes) within stem 2...... each of four independent virus populations were observed that restored the coding sequence to that of the parental field strain. These adaptations occurred with different kinetics. The combination of reverse genetics and in depth, full genome sequencing provides a powerful approach to analyse virus...
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.
Lecouturier, Valerie; Berry, Catherine; Saulnier, Aure; Naville, Sophie; Manin, Catherine; Girerd-Chambaz, Yves; Crowe, James E; Jackson, Nicholas; Guy, Bruno
2018-04-26
The recombinant yellow fever-17D-dengue virus, live, attenuated, tetravalent dengue vaccine (CYD-TDV) is licensed in several dengue-endemic countries. Although the vaccine provides protection against dengue, the level of protection differs by serotype and warrants further investigation. We characterized the antigenic properties of each vaccine virus serotype using highly neutralizing human monoclonal antibodies (hmAbs) that bind quaternary structure-dependent epitopes. Specifically, we monitored the binding of dengue virus-1 (DENV-1; 1F4), DENV-2 (2D22) or DENV-3 (5J7) serotype-specific or DENV-1-4 cross-reactive (1C19) hmAbs to the four chimeric yellow fever-dengue vaccine viruses (CYD-1-4) included in phase III vaccine formulations using a range of biochemical and functional assays (dot blot, ELISA, surface plasmon resonance and plaque reduction neutralization assays). In addition, we used the "classic" live, attenuated DENV-2 vaccine serotype, immature CYD-2 viruses and DENV-2 virus-like particles as control antigens for anti-serotype-2 reactivity. The CYD vaccine serotypes were recognized by each hmAbs with the expected specificity, moreover, surface plasmon resonance indicated a high functional affinity interaction with the CYD serotypes. In addition, the hmAbs provided similar protection against CYD and wild-type dengue viruses in the in vitro neutralization assay. Overall, these findings demonstrate that the four CYD viruses used in clinical trials display key conformational and functional epitopes targeted by serotype-specific and/or cross-reactive neutralizing human antibodies. More specifically, we showed that CYD-2 displays serotype- specific epitopes present only on the mature virus. This indicates that the CYD-TDV has the ability to elicit antibody specificities which are similar to those induced by the wild type DENV. Future investigations will be needed to address the nature of CYD-TDV-induced responses after vaccine administration, and how these
Complete Genomes of Classical Swine Fever Virus Cloned into Bacterial Artificial Chromosomes
DEFF Research Database (Denmark)
Rasmussen, Thomas Bruun; Reimann, I.; Uttenthal, Åse
Complete genome amplification of viral RNA provides a new tool for the generation of modified pestiviruses. We have used our full-genome amplification strategy for generation of amplicons representing complete genomes of classical swine fever virus. The amplicons were cloned directly into a stabl...... single-copy bacterial artificial chromosome (BAC) generating full-length pestivirus DNAs from which infectious RNA transcripts could be also derived. Our strategy allows construction of stable infectious BAC DNAs from a single full-length PCR product....
Tattersall, Timothy Lee; Thangasamy, Isaac A; Reynolds, Jamie
2014-10-14
We present a case of bilateral adrenal haemorrhage (BAH) associated with heparin-induced thrombocytopaenia (HIT) in a 61-year-old man admitted to hospital for the treatment of Fournier's gangrene. He presented to hospital with scrotal swelling and fever, and developed spreading erythaema and a gangrenous scrotum. His scrotum was surgically debrided and intravenous broad-spectrum antibiotics were administered. Unfractionated heparin was given postoperatively for venous thromboembolism prophylaxis. The patient deteriorated clinically 8-11 days postoperatively with delirium, chest pain and severe hypertension followed by hypotension and thrombocytopaenia. Abdominal CT scan revealed bilateral adrenal haemorrhage. Antibodies to the heparin-platelet factor 4 complex were present. HIT-associated BAH was diagnosed and heparin was discontinued. Intravenous bivalirudin and hydrocortisone were started, with rapid improvement in clinical status. BAH is a rare complication of HIT and should be considered in the postoperative patient with unexplained clinical deterioration. 2014 BMJ Publishing Group Ltd.
Vialat, P; Muller, R; Vu, T H; Prehaud, C; Bouloy, M
1997-11-01
The MP12 attenuated strain of Rift Valley fever virus was obtained by 12 serial passages of a virulent isolate ZH548 in the presence of 5-fluorouracil (Caplen et al., 1985. Mutagen-directed attenuation of Rift Valley fever virus as a method for vaccine development. J. Gen. Virol., 66, 2271-2277). The comparison of the M segment of the two strains has already been reported by Takehara et al. (Takehara et al., 1989. Identification of mutations in the M RNA of a candidate vaccine strain of Rift Valley fever virus. Virology 169, 452-457). We have completed the comparison and found that altogether a total of nine, 12 and four nucleotides were changed in the L, M and S segments of the two strains, respectively. Three mutations induced amino acid changes in the L protein but none of them was located in the recognized motifs conserved among RNA dependent polymerases. In the S segment, a single change modified an amino acid in the NSs protein and in the M segment, seven of the mutations resulted in amino acid changes in each of the four encoded G1, G2, 14 kDa and 78 kDa proteins. Characterization of the MP12 virus indicated that determinants for attenuation were present in each segment and that they were introduced progressively during the 12 passages in the presence of the mutagen (Saluzzo and Smith, 1990. Use of reassortant viruses to map attenuating and temperature-sensitive mutations of the Rift Valley fever virus MP-12 vaccine. Vaccine 8, 369-375). Passages 4 and 7-9 were found to be essential for introduction of temperature-sensitive lesions and attenuation. In an attempt to correlate some of the mutations with the attenuated or temperature-sensitive phenotypes, we determined by sequencing the passage level at which the different mutations appeared. This work should help to address the question of the role of the viral gene products in Rift Valley fever pathogenesis.
Kalbina, Irina; Lagerqvist, Nina; Moiane, Bélisario; Ahlm, Clas; Andersson, Sören; Strid, Åke; Falk, Kerstin I
2016-11-01
The zoonotic Rift Valley fever virus affects livestock and humans in Africa and on the Arabian Peninsula. The economic impact of this pathogen due to livestock losses, as well as its relevance to public health, underscores the importance of developing effective and easily distributed vaccines. Vaccines that can be delivered orally are of particular interest. Here, we report the expression in transformed plants (Arabidopsis thaliana) of Rift Valley fever virus antigens. The antigens used in this study were the N protein and a deletion mutant of the Gn glycoprotein. Transformed lines were analysed for specific mRNA and protein content by RT-PCR and Western blotting, respectively. Furthermore, the plant-expressed antigens were evaluated for their immunogenicity in mice fed the transgenic plants. After oral intake of fresh transgenic plant material, a proportion of the mice elicited specific IgG antibody responses, as compared to the control animals that were fed wild-type plants and of which none sero-converted. Thus, we show that transgenic plants can be readily used to express and produce Rift Valley Fever virus proteins, and that the plants are immunogenic when given orally to mice. These are promising findings and provide a basis for further studies on edible plant vaccines against the Rift Valley fever virus. Copyright © 2016 Elsevier Inc. All rights reserved.
Potential for Mosquitoes (Diptera: Culicidae) From Florida to Transmit Rift Valley Fever Virus
2013-09-01
signiÞcant disease and economic disruption. Rift Valley fever virus (RVFV), whichhasbeen responsible fornumerousoutbreaksof severe disease in ruminants and...is predominately a disease of domestic ruminants (cattle, goats, and sheep), where infection in pregnant animals usually results in abortion, and...www.cdc.gov/EID/ content /13/8/e1.htm). Britch, S.C.,K. J.Linthicum,A.Anyamba,C. J.Tucker,E.W. Pak, F. A. Maloney, K. Cobb, E. Stanwix, J. Humphries, A
Caì, Yíngyún; Postnikova, Elena N.; Bernbaum, John G.; Yú, Shuǐqìng; Mazur, Steven; Deiuliis, Nicole M.; Radoshitzky, Sheli R.; Lackemeyer, Matthew G.; McCluskey, Adam; Robinson, Phillip J.; Haucke, Volker; Wahl-Jensen, Victoria; Bailey, Adam L.; Lauck, Michael; Friedrich, Thomas C.
2014-01-01
Simian hemorrhagic fever virus (SHFV) causes a severe and almost uniformly fatal viral hemorrhagic fever in Asian macaques but is thought to be nonpathogenic for humans. To date, the SHFV life cycle is almost completely uncharacterized on the molecular level. Here, we describe the first steps of the SHFV life cycle. Our experiments indicate that SHFV enters target cells by low-pH-dependent endocytosis. Dynamin inhibitors, chlorpromazine, methyl-β-cyclodextrin, chloroquine, and concanamycin A ...
Evidence for widespread infection of African bats with Crimean-Congo hemorrhagic fever-like viruses
Czech Academy of Sciences Publication Activity Database
Müller, M. A.; Devignot, S.; Lattwein, E.; Corman, V. M.; Maganga, G. D.; Gloza-Rausch, F.; Binger, T.; Vallo, Peter; Emmerich, P.; Cottontail, V. M.; Tschapka, M.; Oppong, S.; Drexler, J. F.; Weber, F.; Leroy, E. M.; Drosten, C.
2016-01-01
Roč. 6, č. 26637 (2016), č. článku 26637. ISSN 2045-2322 EU Projects: European Commission(XE) 278976 - ANTIGONE; European Commission(XE) 260427 - CCH Fever Institutional support: RVO:68081766 Keywords : sheep disease virus * family Bunyaviridae * serological relationships * antibody-response * migratory birds * rapid detection * viral load * ticks * nairovirus * genus Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 4.259, year: 2016
Directory of Open Access Journals (Sweden)
Kang Tang
2017-01-01
Full Text Available Haemorrhagic fever with renal syndrome (HFRS is characterised by an uncontrolled immune response that causes vascular leakage. Adiponectin (APN is an adipocytokine involved in prorevascularisation and immunomodulation. To investigate the possible effects of APN in the pathogenesis of HFRS, total and high molecular weight (HMW APN levels in the plasma of patients with HFRS were quantified using enzyme-linked immunosorbent assay (ELISA. Compared with those in healthy controls, the plasma total and HMW APN levels in patients were elevated to different degrees from the fever onset and remained high at the convalescent phase. Consistent with these results, western blot analysis additionally showed that low molecular weight (LMW, middle molecular weight (MMW, and HMW APN levels were all elevated and contributed to the elevation of the total APN level. Importantly, sustained high levels of total and HMW APN at the convalescent phase were significantly higher in patients with critical disease than those in patients with mild or moderate disease. Moreover, total and HMW APN levels negatively correlated with white blood cell count and positively correlated with platelet count and serum albumin level. These results may provide insights into understanding the roles of total and HMW APN in the pathogenesis of HFRS.
Hercules Sakkas; Petros Bozidis; Ashley Franks; Chrissanthy Papadopoulou
2018-01-01
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 s...
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Nikhil Vasdev
2013-10-01
Full Text Available Aim: Haemorrhagic cystitis (HC is uncommon and in its severe form potentially life threatening complication of Haematopoietic stem cell transplantation (HSCT in children. We present our single centre experience in the urological management of this clinically challenging condition. Patients and Methods: Fourteen patients were diagnosed with BK-Virus HC in our centre. The mean age at diagnosis was 8.8 years (range, 3.2-18.4 years. The mean number of days post-BMT until onset of HC was 20.8 (range, 1 – 51. While all patients tested urine positive for BKV at the clinical onset of HC, only four patients had viral quantification, with viral loads ranging from 97,000 to >1 billion/ml. 8 patients had clinical HC. Ten patients experienced acute GVHD (grade I: 6 patients, grade II: 3 patients, grade 4: 1 patient.Results: Four patients received medical management for their HC. Treatments included hyperhydration, MESNA, blood and platelet transfusion, premarin and oxybutynin (Table 6. Two patients received both medical and surgical management which included cystoscopy with clot evacuation, bladder irrigation and supra-pubic catheter insertion. One patient received exclusive surgical management. Seven patients were treated conservatively. Conclusion: There is limited available evidence for other potential therapeutic strategies highlighting the need for more research into the pathophysiology of HSCT-associated HC. Commonly used interventions with possible clinical benefit (e.g. cidofovir, ciprofloxacin still require to be evaluated in multi-centre, high-quality studies. Potential future preventative and therapeutic options, such as modulation of conditioning, immunosuppression and engraftment, new antiviral and anti-inflammatory and less nephrotoxic agents need to be assessed.---------------------------Cite this article as:Vasdev N, Davidson A, Harkensee C, Slatter M, Gennery A, Willetts I, Thorpe A.Urological management (medical and surgical of BK-virus
Dengue hemorrhagic fever and acute hepatitis: a case report
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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.
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.
Tabachnick, Walter J
2016-09-29
The impact of anticipated changes in global climate on the arboviruses and the diseases they cause poses a significant challenge for public health. The past evolution of the dengue and yellow fever viruses provides clues about the influence of changes in climate on their future evolution. The evolution of both viruses has been influenced by virus interactions involving the mosquito species and the primate hosts involved in virus transmission, and by their domestic and sylvatic cycles. Information is needed on how viral genes in general influence phenotypic variance for important viral functions. Changes in global climate will alter the interactions of mosquito species with their primate hosts and with the viruses in domestic cycles, and greater attention should be paid to the sylvatic cycles. There is great danger for the evolution of novel viruses, such as new serotypes, that could compromise vaccination programs and jeopardize public health. It is essential to understand (a) both sylvatic and domestic cycles and (b) the role of virus genetic and environmental variances in shaping virus phenotypic variance to more fully assess the impact of global climate change.
[Marburg and Ebola hemorrhagic fevers--pathogens, epidemiology and therapy].
Stock, Ingo
2014-09-01
Marburg and Ebola hemorrhagic fevers are severe, systemic viral diseases affecting humans and non-human primates. They are characterized by multiple symptoms such as hemorrhages, fever, headache, muscle and abdominal pain, chills, sore throat, nausea, vomiting and diarrhea. Elevated liver-associated enzyme levels and coagulopathy are also associated with these diseases. Marburg and Ebola hemorrhagic fevers are caused by (Lake victoria) Marburg virus and different species of Ebola viruses, respectively. They are enveloped, single-stranded RNA viruses and belong to the family of filoviridae. Case fatality rates of filovirus disease outbreaks are among the highest reported for any human pathogen, ranging from 25 to 90% or more. Outbreaks of Marburg and Ebola hemorrhagic fever occur in certain regions of equatorial Africa at irregular intervals. Since 2000, the number of outbreaks has increased. In 2014, the biggest outbreak of a filovirus-induced hemorrhagic fever that has been documented so far occurred from March to July 2014 in Guinea, Sierra Leone, Liberia and Nigeria. The outbreak was caused by a new variant of Zaire Ebola-Virus, affected more than 2600 people (stated 20 August) and was associated with case-fatality rates of up to 67% (Guinea). Treatment of Marburg and Ebola hemorrhagic fevers is symptomatic and supportive, licensed antiviral agents are currently not available. Recently, BCX4430, a promising synthetic adenosine analogue with high in vitro and in vivo activity against filoviruses and other RNA viruses, has been described. BCX4430 inhibits viral RNA polymerase activity and protects cynomolgus macaques from Marburg virus infection when administered as late as 48 hours after infection. Nucleic acid-based products, recombinant vaccines and antibodies appear to be less suitable for the treatment of Marburg and Ebola hemorrhagic fevers.
A mini-review of Bunyaviruses recorded in India.
Yadav, Pragya D; Chaubal, Gouri Y; Shete, Anita M; Mourya, Devendra T
2017-05-01
Newly emerging and re-emerging viral infections are of major public health concern. Bunyaviridae family of viruses comprises a large group of animal viruses. Clinical symptoms exhibited by persons infected by viruses belonging to this family vary from mild-to-severe diseases i.e., febrile illness, encephalitis, haemorrhagic fever and acute respiratory illness. Several arthropods-borne viruses have been discovered and classified at serological level in India in the past. Some of these are highly pathogenic as the recent emergence and spread of Crimean-Congo haemorrhagic fever virus and presence of antibodies against Hantavirus in humans in India have provided evidences that it may become one of the emerging diseases in this country. For many of the discovered viruses, we still need to study their relevance to human and animal health. Chittoor virus, a variant of Batai virus; Ganjam virus, an Asian variant of Nairobi sheep disease virus; tick-borne viruses such as Bhanja, Palma and mosquito-borne viruses such as Sathuperi, Thimiri, Umbre and Ingwavuma viruses have been identified as the members of this family. As Bunyaviruses are three segmented RNA viruses, they can reassort the segments into genetically distinct viruses in target cells. This ability is believed to play a major role in evolution, pathogenesis and epidemiology of the viruses. Here, we provide a comprehensive overview of discovery, emergence and distribution of Bunyaviruses in India.
A mini-review of Bunyaviruses recorded in India
Directory of Open Access Journals (Sweden)
Pragya D Yadav
2017-01-01
Full Text Available Newly emerging and re-emerging viral infections are of major public health concern. Bunyaviridae family of viruses comprises a large group of animal viruses. Clinical symptoms exhibited by persons infected by viruses belonging to this family vary from mild-to-severe diseases i.e., febrile illness, encephalitis, haemorrhagic fever and acute respiratory illness. Several arthropods-borne viruses have been discovered and classified at serological level in India in the past. Some of these are highly pathogenic as the recent emergence and spread of Crimean-Congo haemorrhagic fever virus and presence of antibodies against Hantavirus in humans in India have provided evidences that it may become one of the emerging diseases in this country. For many of the discovered viruses, we still need to study their relevance to human and animal health. Chittoor virus, a variant of Batai virus; Ganjam virus, an Asian variant of Nairobi sheep disease virus; tick-borne viruses such as Bhanja, Palma and mosquito-borne viruses such as Sathuperi, Thimiri, Umbre and Ingwavuma viruses have been identified as the members of this family. As Bunyaviruses are three segmented RNA viruses, they can reassort the segments into genetically distinct viruses in target cells. This ability is believed to play a major role in evolution, pathogenesis and epidemiology of the viruses. Here, we provide a comprehensive overview of discovery, emergence and distribution of Bunyaviruses in India.
Dengue fever: a Wikipedia clinical review
Heilman, James M; Wolff, Jacob De; Beards, Graham M; Basden, Brian J
2014-01-01
Dengue fever, also known as breakbone fever, is a mosquito-borne infectious tropical disease caused by the dengue virus. Symptoms include fever, headache, muscle and joint pains, and a characteristic skin rash that is similar to measles. In a small proportion of cases, the disease develops into life-threatening dengue hemorrhagic fever, which results in bleeding, thrombocytopenia, and leakage of blood plasma, or into dengue shock syndrome, in which dangerously low blood pressure occurs. Treat...
Hall, R N; Mahar, J E; Read, A J; Mourant, R; Piper, M; Huang, N; Strive, T
2018-04-01
Rabbit haemorrhagic disease virus (RHDV, or GI.1) is a calicivirus in the genus Lagovirus that has been widely utilized in Australia as a biological control agent for the management of overabundant wild European rabbit (Oryctolagus cuniculus) populations since 1996. Recently, two exotic incursions of pathogenic lagoviruses have been reported in Australia; GI.1a-Aus, previously called RHDVa-Aus, is a GI.1a virus detected in January 2014, and the novel lagovirus GI.2 (previously known as RHDV2). Furthermore, an additional GI.1a strain, GI.1a-K5 (also known as 08Q712), was released nationwide in March 2017 as a supplementary tool for wild rabbit management. To discriminate between these lagoviruses, a highly sensitive strain-specific multiplex RT-PCR assay was developed, which allows fast, cost-effective and sensitive detection of the four pathogenic lagoviruses currently known to be circulating in Australia. In addition, we developed a universal RT-qPCR assay to be used in conjunction with the multiplex assay that broadly detects all four viruses and facilitates quantification of viral RNA load in samples. These assays enable rapid detection, identification and quantification of pathogenic lagoviruses in the Australian context. Using these assays, a novel recombinant lagovirus was detected in rabbit tissue samples, which contained the non-structural genes of GI.1a-Aus and the structural genes of GI.2. This variant was also recovered from the liver of a European brown hare (Lepus europaeus). The impact of this novel recombinant on Australian wild lagomorph populations and its competitiveness in relation to circulating field strains, particularly GI.2, requires further studies. © 2017 Blackwell Verlag GmbH.
Macdonald, Joanne; Poidinger, Michael; Mackenzie, John S; Russell, Richard C; Doggett, Stephen; Broom, Annette K; Phillips, Debra; Potamski, Joseph; Gard, Geoff; Whelan, Peter; Weir, Richard; Young, Paul R; Gendle, Debra; Maher, Sheryl; Barnard, Ross T; Hall, Roy A
2010-06-15
Edge Hill virus (EHV) is a mosquito-borne flavivirus isolated throughout Australia during mosquito surveillance programs. While not posing an immediate threat to the human population, EHV is a taxonomically interesting flavivirus since it remains the only member of the yellow fever virus (YFV) sub-group to be detected within Australia. Here we present both an antigenic and genetic investigation of collected isolates, and confirm taxonomic classification of the virus within the YFV-group. Isolates were not clustered based on geographical origin or time of isolation, suggesting that minimal genetic evolution of EHV has occurred over geographic distance or time within the EHV cluster. However, two isolates showed significant differences in antigenic reactivity patterns, and had a much larger divergence from the EHV prototype (19% nucleotide and 6% amino acid divergence), indicating a distinct subtype or variant within the EHV subgroup.
Prevalence and titers of yellow fever virus neutralizing antibodies in previously vaccinated adults.
Miyaji, Karina Takesaki; Avelino-Silva, Vivian Iida; Simões, Marisol; Freire, Marcos da Silva; Medeiros, Carlos Roberto de; Braga, Patrícia Emilia; Neves, Maria Angélica Acalá; Lopes, Marta Heloisa; Kallas, Esper Georges; Sartori, Ana Marli Christovam
2017-04-03
The World Health Organization (WHO) recommends one single dose of the Yellow Fever (YF) vaccine based on studies of antibody persistency in healthy adults. We assessed the prevalence and titers of YF virus neutralizing antibodies in previously vaccinated persons aged 60 years, in comparison to younger adults. We also evaluated the correlation between antibody titers and the time since vaccination among participants who received one vaccine dose, and the seropositivity among participants vaccinated prior to or within the past 10 years. previously vaccinated healthy persons aged 18 years were included. YF virus neutralizing antibody titers were determined by means of the 50% Plaque Reduction Neutralization Test. 46 persons aged 60 years and 48 persons aged 18 to 59 years were enrolled. There was no significant difference in the prevalence of YF virus neutralizing antibodies between the two groups (p = 0.263). However, titers were significantly lower in the elderly (p = 0.022). There was no correlation between YF virus neutralizing antibody titers and the time since vaccination. There was no significant difference in seropositivity among participants vaccinated prior to or within the past 10 years. the clinical relevance of the observed difference in YF virus neutralizing antibody titers between the two groups is not clear.
DEFF Research Database (Denmark)
Jonstrup, Søren Peter; Gray, Tanya; Kahns, Søren
2009-01-01
A database has been created, http://www.Fish Pathogens.eu, with the aim of providing a single repository for collating important information on significant pathogens of aquaculture, relevant to their control and management. This database will be developed, maintained and managed as part of the Eu......A database has been created, http://www.Fish Pathogens.eu, with the aim of providing a single repository for collating important information on significant pathogens of aquaculture, relevant to their control and management. This database will be developed, maintained and managed as part...... of the European Community Reference Laboratory for Fish Diseases function. This concept has been initially developed for viral haemorrhagic septicaemia virus and will be extended in future to include information on other significant aquaculture pathogens. Information included for each isolate comprises sequence...... to obtain data from any selected part of the genome of interest. The output of the sequence search can be readily retrieved as a FASTA file ready to be imported into a sequence alignment tool of choice, facilitating further molecular epidemiological study....
A Novel System for Identification of Inhibitors of Rift Valley Fever Virus Replication
Piper, Mary E.; Gerrard, Sonja R.
2010-01-01
Rift Valley fever virus (RVFV) is a human and livestock pathogen endemic to sub-Saharan Africa. We have developed a T7-dependent system for the efficient production of RVFV-like particles (RVF-VLPs) based on the virulent ZH-501 strain of RVFV. The RVF-VLPs are capable of performing a single round of infection, allowing for the study of viral replication, assembly, and infectivity. We demonstrate that these RVF-VLPs are antigenically indistinguishable from authentic RVFV and respond similarly ...
Ebola virus disease: past, present and future
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Harish Rajak
2015-05-01
Full Text Available Ebola virus disease is one of the most deadly ailments known to mankind due to its high mortality rate (up to 90% accompanying with the disease. Ebola haemorrhagic fever (EHF is an infectious disease of animal that can be transmitted to both human and non-human primates. The first epidemic of EHF occurred in 1976 in the Democratic Republic of the Congo. The incubation period of ebola is less than 21 days. Ebola virus infections are depicted by immune suppression and a systemic inflammatory response that leads to damage of the vascular, coagulation and immune systems, causing multi-organ failure and shock. Five genetically distinct members of the Filoviridae family responsible for EHF are as follows: Zaire ebolavirus, Sudan ebolavirus, Côte d’Ivoire ebolavirus, Bundibugyo ebolavirus and Reston ebolavirus. The ongoing 2014 West Africa ebola epidemic has been considered as the most serious panic in the medical field with respect to both the number of human cases and death toll. The natural host for ebola virus is unknown, thus it is not possible to carry out programs to regulate or abolish virus from transmission to people. The ebola virus infection provides little chance to develop acquired immunity causing rapid progression of the disease. It is pertinent to mention that at present, there is no antiviral therapy or vaccine that is helpful against ebola virus infection in humans. The impediment of EHF necessitates much better understanding of the epidemiology of the disease, particularly the role of wildlife, as well as bats, in the spread of ebola virus to humans.
The yellow fever 17D virus as a platform for new live attenuated vaccines.
Bonaldo, Myrna C; Sequeira, Patrícia C; Galler, Ricardo
2014-01-01
The live-attenuated yellow fever 17D virus is one of the most outstanding human vaccines ever developed. It induces efficacious immune responses at a low production cost with a well-established manufacture process. These advantages make the YF17D virus attractive as a vector for the development of new vaccines. At the beginning of vector development studies, YF17D was genetically manipulated to express other flavivirus prM and E proteins, components of the viral envelope. While these 17D recombinants are based on the substitution of equivalent YF17D genes, other antigens from unrelated pathogens have also been successfully expressed and delivered by recombinant YF17D viruses employing alternative strategies for genetic manipulation of the YF17D genome. Herein, we discuss these strategies in terms of possibilities of single epitope or larger sequence expression and the main properties of these replication-competent viral platforms.
STUDIES ON SOUTH AMERICAN YELLOW FEVER
Davis, Nelson C.; Shannon, Raymond C.
1929-01-01
Yellow fever virus from M. rhesus has been inoculated into a South American monkey (Cebus macrocephalus) by blood injection and by bites of infected mosquitoes. The Cebus does not develop the clinical or pathological signs of yellow fever. Nevertheless, the virus persists in the Cebus for a time as shown by the typical symptoms and lesions which develop when the susceptible M. rhesus is inoculated from a Cebus by direct transfer of blood or by mosquito (A. aegypti) transmission. PMID:19869607
Outbreak of viral hemorrhagic fever caused by dengue virus type 3 in Al-Mukalla, Yemen.
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
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
A hamster model for Marburg virus infection accurately recapitulates Marburg hemorrhagic fever.
Marzi, Andrea; Banadyga, Logan; Haddock, Elaine; Thomas, Tina; Shen, Kui; Horne, Eva J; Scott, Dana P; Feldmann, Heinz; Ebihara, Hideki
2016-12-15
Marburg virus (MARV), a close relative of Ebola virus, is the causative agent of a severe human disease known as Marburg hemorrhagic fever (MHF). No licensed vaccine or therapeutic exists to treat MHF, and MARV is therefore classified as a Tier 1 select agent and a category A bioterrorism agent. In order to develop countermeasures against this severe disease, animal models that accurately recapitulate human disease are required. Here we describe the development of a novel, uniformly lethal Syrian golden hamster model of MHF using a hamster-adapted MARV variant Angola. Remarkably, this model displayed almost all of the clinical features of MHF seen in humans and non-human primates, including coagulation abnormalities, hemorrhagic manifestations, petechial rash, and a severely dysregulated immune response. This MHF hamster model represents a powerful tool for further dissecting MARV pathogenesis and accelerating the development of effective medical countermeasures against human MHF.
Hemophagocytic syndrome in classic dengue fever
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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.
Coinfection with influenza A(H1N1)pdm09 and dengue virus in fatal cases.
Perdigão, Anne Carolinne Bezerra; Ramalho, Izabel Letícia Cavalcante; Guedes, Maria Izabel Florindo; Braga, Deborah Nunes Melo; Cavalcanti, Luciano Pamplona Góes; Melo, Maria Elisabeth Lisboa de; Araújo, Rafael Montenegro de Carvalho; Lima, Elza Gadelha; Silva, Luciene Alexandre Bié da; Araújo, Lia de Carvalho; Araújo, Fernanda Montenegro de Carvalho
2016-09-01
We report on four patients with fatal influenza A(H1N1)pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses' epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4). Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998). As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015). In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm), caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010). In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013). The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1)pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013). The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1)pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.
Palomar, Ana M; Portillo, Aránzazu; Santibáñez, Sonia; García-Álvarez, Lara; Muñoz-Sanz, Agustín; Márquez, Francisco J; Romero, Lourdes; Eiros, José M; Oteo, José A
Crimean-Congo hemorrhagic fever (CCHF) is a viral disease, mainly transmitted through tick bite, of great importance in Public Health. In Spain, Crimean-Congo hemorrhagic fever virus (CCHFV) was detected for the first time in 2010 in Hyalomma lusitanicum ticks collected from deer in Cáceres. The aim of this study was to investigate the presence of CCHFV in ticks from Cáceres, and from other Spanish areas, and to evaluate the presence of antibodies against the virus in individuals exposed to tick bites. A total of 2053 ticks (1333 Hyalomma marginatum, 680 H. lusitanicum and 40 Rhipicephalus bursa) were analyzed using molecular biology techniques (PCR) for CCHFV detection. The determination of specific IgG antibodies against CCHFV in 228 serum samples from humans with regular contact with ticks (at risk of acquiring the infection) was performed by indirect immunofluorescence assay. The CCHFV was not amplified in ticks, nor were antibodies against the virus found in the serum samples analyzed. The absence of the CCHFV in the ticks studied and the lack of antibodies against the virus in individuals exposed to tick bites would seem to suggest a low risk of acquisition of human infection by CCHFV in Spain. Copyright © 2017 Elsevier España, S.L.U. and Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Modeled Forecasts of Dengue Fever in San Juan, PR Using NASA Satellite Enhanced Weather Forecasts
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).
Directory of Open Access Journals (Sweden)
Joanne Macdonald
2010-06-01
Full Text Available Edge Hill virus (EHV is a mosquito-borne flavivirus isolated throughout Australia during mosquito surveillance programs. While not posing an immediate threat to the human population, EHV is a taxonomically interesting flavivirus since it remains the only member of the yellow fever virus (YFV sub-group to be detected within Australia. Here we present both an antigenic and genetic investigation of collected isolates, and confirm taxonomic classification of the virus within the YFV-group. Isolates were not clustered based on geographical origin or time of isolation, suggesting that minimal genetic evolution of EHV has occurred over geographic distance or time within the EHV cluster. However, two isolates showed significant differences in antigenic reactivity patterns, and had a much larger divergence from the EHV prototype (19% nucleotide and 6% amino acid divergence, indicating a distinct subtype or variant within the EHV subgroup.
DEFF Research Database (Denmark)
Tahmasebi, F; Ghiasi, Seyed Mojtaba; Mostafavi, E
2010-01-01
BACKGROUND & OBJECTIVES: Crimean-Congo hemorrhagic fever (CCHF) virus is a tick-borne member of the genus Nairovirus, family Bunyaviridae. CCHFV has been isolated from at least 31 different tick species. The virus is transmitted through the bite of an infected tick, or by direct contact with CCHFV...... to each other. Even though they clustered in the same group with the strain circulating in Iran, they had a closer relationship to the Matin strain. INTERPRETATION & CONCLUSION: Vector control programs should be applied for reducing population density of potential tick vectors in this province. Further...
Jiang, Xiaohong; Dalebout, Tim J; Bredenbeek, Peter J; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S; Lukashevich, Igor S
2011-02-01
Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV-GP1 and -GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and -GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF proteins and LASV GP antigens in infected cells. YF17D/LASV-GP1 and -GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1 and -GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. Copyright © 2010 Elsevier Ltd. All rights reserved.
Jiang, Xiaohong; Dalebout, Tim J.; Bredenbeek, Peter J.; Carrion, Ricardo; Brasky, Kathleen; Patterson, Jean; Goicochea, Marco; Bryant, Joseph; Salvato, Maria S.; Lukashevich, Igor S.
2010-01-01
Yellow Fever (YF) and Lassa Fever (LF) are two prevalent hemorrhagic fevers co-circulating in West Africa and responsible for thousands of deaths annually. The YF vaccine 17D has been used as a vector for the Lassa virus glycoprotein precursor (LASV-GPC) or their subunits, GP1 (attachment glycoprotein) and GP2 (fusion glycoprotein). Cloning shorter inserts, LASV GP1 and GP2, between YF17D E and NS1 genes enhanced genetic stability of recombinant viruses, YF17D/LASV-GP1 and –GP2, in comparison with YF17D/LASV-GPC recombinant. The recombinant viruses were replication competent and properly processed YF and LASV GP proteins in infected cells. YF17D/LASV-GP1&GP2 induced specific CD8+ T cell responses in mice and protected strain 13 guinea pigs against fatal LF. Unlike immunization with live attenuated reassortant vaccine ML29, immunization with YF17D/LASV-GP1&GP2 did not provide sterilizing immunity. This study demonstrates the feasibility of YF17D-based vaccine to control LF in West Africa. PMID:21145373
Biological and phylogenetic characteristics of yellow fever virus lineages from West Africa.
Stock, Nina K; Laraway, Hewád; Faye, Ousmane; Diallo, Mawlouth; Niedrig, Matthias; Sall, Amadou A
2013-03-01
The yellow fever virus (YFV), the first proven human-pathogenic virus, although isolated in 1927, is still a major public health problem, especially in West Africa where it causes outbreaks every year. Nevertheless, little is known about its genetic diversity and evolutionary dynamics, mainly due to a limited number of genomic sequences from wild virus isolates. In this study, we analyzed the phylogenetic relationships of 24 full-length genomes from YFV strains isolated between 1973 and 2005 in a sylvatic context of West Africa, including 14 isolates that had previously not been sequenced. By this, we confirmed genetic variability within one genotype by the identification of various YF lineages circulating in West Africa. Further analyses of the biological properties of these lineages revealed differential growth behavior in human liver and insect cells, correlating with the source of isolation and suggesting host adaptation. For one lineage, repeatedly isolated in a context of vertical transmission, specific characteristics in the growth behavior and unique mutations of the viral genome were observed and deserve further investigation to gain insight into mechanisms involved in YFV emergence and maintenance in nature.
Risk of subarachnoid haemorrhage in first degree relatives of patients with subarachnoid haemorrhage
DEFF Research Database (Denmark)
Gaist, D; Vaeth, M; Tsiropoulos, I
2000-01-01
OBJECTIVE: To estimate the risk of occurrence of subarachnoid haemorrhage in first degree relatives (parents, siblings, children) of patients with subarachnoid haemorrhage. DESIGN: Population based cohort study using data from the Danish National Discharge Registry and the Central Person Registry......, standardised for age, sex, and calendar period. This process was repeated for patients discharged from neurosurgery units, as diagnoses from these wards had high validity (93%). RESULTS: 18 patients had a total of 19 first degree relatives with subarachnoid haemorrhage during the study period, corresponding...... to a standardised incidence ratio of 2.9 (95% confidence interval 1.9 to 4.6). Patients discharged from neurosurgery wards had a higher standardised incidence ratio (4.5, 2.7 to 7.3). CONCLUSIONS: First degree relatives of patients with subarachnoid haemorrhage have a threefold to fivefold increased risk...
Rift Valley fever virus NS{sub S} gene expression correlates with a defect in nuclear mRNA export
Energy Technology Data Exchange (ETDEWEB)
Copeland, Anna Maria; Van Deusen, Nicole M.; Schmaljohn, Connie S., E-mail: Connie.s.schmaljohn.civ@mail.mil
2015-12-15
We investigated the localization of host mRNA during Rift Valley fever virus (RVFV) infection. Fluorescence in situ hybridization revealed that infection with RVFV altered the localization of host mRNA. mRNA accumulated in the nuclei of RVFV-infected but not mock-infected cells. Further, overexpression of the NS{sub S} gene, but not the N, G{sub N} or NS{sub M} genes correlated with mRNA nuclear accumulation. Nuclear accumulation of host mRNA was not observed in cells infected with a strain of RVFV lacking the gene encoding NS{sub S}, confirming that expression of NS{sub S} is likely responsible for this phenomenon. - Highlights: • Rift Valley fever virus (RVFV) infection alters the localization of host mRNA. • mRNA accumulates in the nuclei of RVFV-infected but not mock-infected cells. • NS{sub S} is likely responsible for mRNA relocalization to the nucleus.
Crawford, Timothy B; Li, Hong; Rosenburg, Stuart R; Norhausen, Robert W; Garner, Michael M
2002-09-15
Two sika deer from a zoo in Florida were examined because of chronic hair loss and skin lesions. No common causes of alopecia were identified in either deer. One deer was treated with prednisone, but the condition worsened when the dosage was decreased. Both deer were euthanatized after several months because of continued disease. The predominant histologic lesion in skin specimens was granulomatous mural folliculitis. Serologic testing and sequencing of fragments produced with a consensus polymerase chain reaction assay indicated that both deer were infected with caprine herpesvirus-2, a newly recognized member of the malignant catarrhal fever group of viruses. Disease in these deer was substantially different from that typically seen following infection with ovine herpesvirus-2, the sheep-associated malignant catarrhal fever virus. Findings in these deer establish the pathogenicity of caprine herpesvirus-2 in sika deer and illustrate the ability of this group of complex herpesviruses to cause a wide variety of clinical abnormalities in diverse species.
Clinical features and patient management of Lujo hemorrhagic fever.
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Nivesh H Sewlall
Full Text Available In 2008 a nosocomial outbreak of five cases of viral hemorrhagic fever due to a novel arenavirus, Lujo virus, occurred in Johannesburg, South Africa. Lujo virus is only the second pathogenic arenavirus, after Lassa virus, to be recognized in Africa and the first in over 40 years. Because of the remote, resource-poor, and often politically unstable regions where Lassa fever and other viral hemorrhagic fevers typically occur, there have been few opportunities to undertake in-depth study of their clinical manifestations, transmission dynamics, pathogenesis, or response to treatment options typically available in industrialized countries.We describe the clinical features of five cases of Lujo hemorrhagic fever and summarize their clinical management, as well as providing additional epidemiologic detail regarding the 2008 outbreak. Illness typically began with the abrupt onset of fever, malaise, headache, and myalgias followed successively by sore throat, chest pain, gastrointestinal symptoms, rash, minor hemorrhage, subconjunctival injection, and neck and facial swelling over the first week of illness. No major hemorrhage was noted. Neurological signs were sometimes seen in the late stages. Shock and multi-organ system failure, often with evidence of disseminated intravascular coagulopathy, ensued in the second week, with death in four of the five cases. Distinctive treatment components of the one surviving patient included rapid commencement of the antiviral drug ribavirin and administration of HMG-CoA reductase inhibitors (statins, N-acetylcysteine, and recombinant factor VIIa.Lujo virus causes a clinical syndrome remarkably similar to Lassa fever. Considering the high case-fatality and significant logistical impediments to controlled treatment efficacy trials for viral hemorrhagic fever, it is both logical and ethical to explore the use of the various compounds used in the treatment of the surviving case reported here in future outbreaks
Habjan, Matthias; Pichlmair, Andreas; Elliott, Richard M; Overby, Anna K; Glatter, Timo; Gstaiger, Matthias; Superti-Furga, Giulio; Unger, Hermann; Weber, Friedemann
2009-05-01
Rift Valley fever virus (RVFV) continues to cause large outbreaks of acute febrile and often fatal illness among humans and domesticated animals in Africa, Saudi Arabia, and Yemen. The high pathogenicity of this bunyavirus is mainly due to the viral protein NSs, which was shown to prevent transcriptional induction of the antivirally active type I interferons (alpha/beta interferon [IFN-alpha/beta]). Viruses lacking the NSs gene induce synthesis of IFNs and are therefore attenuated, whereas the noninducing wild-type RVFV strains can only be inhibited by pretreatment with IFN. We demonstrate here in vitro and in vivo that a substantial part of the antiviral activity of IFN against RVFV is due to a double-stranded RNA-dependent protein kinase (PKR). PKR-mediated virus inhibition, however, was much more pronounced for the strain Clone 13 with NSs deleted than for the NSs-expressing strain ZH548. In vivo, Clone 13 was nonpathogenic for wild-type (wt) mice but could regain pathogenicity if mice lacked the PKR gene. ZH548, in contrast, killed both wt and PKR knockout mice indiscriminately. ZH548 was largely resistant to the antiviral properties of PKR because RVFV NSs triggered the specific degradation of PKR via the proteasome. The NSs proteins of the related but less virulent sandfly fever Sicilian virus and La Crosse virus, in contrast, had no such anti-PKR activity despite being efficient suppressors of IFN induction. Our data suggest that RVFV NSs has gained an additional anti-IFN function that may explain the extraordinary pathogenicity of this virus.
Yellow Fever 17DD Vaccine Virus Infection Causes Detectable Changes in Chicken Embryos.
Manso, Pedro Paulo de Abreu; Dias de Oliveira, Barbara C E P; de Sequeira, Patrícia Carvalho; Maia de Souza, Yuli Rodrigues; Ferro, Jessica Maria dos Santos; da Silva, Igor José; Caputo, Luzia Fátima Gonçalves; Guedes, Priscila Tavares; dos Santos, Alexandre Araujo Cunha; Freire, Marcos da Silva; Bonaldo, Myrna Cristina; Pelajo-Machado, Marcelo
2015-01-01
The yellow fever (YF) 17D vaccine is one of the most effective human vaccines ever created. The YF vaccine has been produced since 1937 in embryonated chicken eggs inoculated with the YF 17D virus. Yet, little information is available about the infection mechanism of YF 17DD virus in this biological model. To better understand this mechanism, we infected embryos of Gallus gallus domesticus and analyzed their histopathology after 72 hours of YF infection. Some embryos showed few apoptotic bodies in infected tissues, suggesting mild focal infection processes. Confocal and super-resolution microscopic analysis allowed us to identify as targets of viral infection: skeletal muscle cells, cardiomyocytes, nervous system cells, renal tubular epithelium, lung parenchyma, and fibroblasts associated with connective tissue in the perichondrium and dermis. The virus replication was heaviest in muscle tissues. In all of these specimens, RT-PCR methods confirmed the presence of replicative intermediate and genomic YF RNA. This clearer characterization of cell targets in chicken embryos paves the way for future development of a new YF vaccine based on a new cell culture system.
Yellow Fever 17DD Vaccine Virus Infection Causes Detectable Changes in Chicken Embryos
Manso, Pedro Paulo de Abreu; Dias de Oliveira, Barbara C. E. P.; de Sequeira, Patrícia Carvalho; Maia de Souza, Yuli Rodrigues; Ferro, Jessica Maria dos Santos; da Silva, Igor José; Caputo, Luzia Fátima Gonçalves; Guedes, Priscila Tavares; dos Santos, Alexandre Araujo Cunha; Freire, Marcos da Silva; Bonaldo, Myrna Cristina; Pelajo-Machado, Marcelo
2015-01-01
The yellow fever (YF) 17D vaccine is one of the most effective human vaccines ever created. The YF vaccine has been produced since 1937 in embryonated chicken eggs inoculated with the YF 17D virus. Yet, little information is available about the infection mechanism of YF 17DD virus in this biological model. To better understand this mechanism, we infected embryos of Gallus gallus domesticus and analyzed their histopathology after 72 hours of YF infection. Some embryos showed few apoptotic bodies in infected tissues, suggesting mild focal infection processes. Confocal and super-resolution microscopic analysis allowed us to identify as targets of viral infection: skeletal muscle cells, cardiomyocytes, nervous system cells, renal tubular epithelium, lung parenchyma, and fibroblasts associated with connective tissue in the perichondrium and dermis. The virus replication was heaviest in muscle tissues. In all of these specimens, RT-PCR methods confirmed the presence of replicative intermediate and genomic YF RNA. This clearer characterization of cell targets in chicken embryos paves the way for future development of a new YF vaccine based on a new cell culture system. PMID:26371874
Antigenic variants of yellow fever virus with an altered neurovirulence phenotype in mice.
Ryman, K D; Xie, H; Ledger, T N; Campbell, G A; Barrett, A D
1997-04-14
The live-attenuated yellow fever (YF) vaccine virus, strain 17D-204, has long been known to consist of a heterologous population of virions. Gould et al. (J. Gen. Virol. 70, 1889-1894 (1989)) previously demonstrated that variant viruses exhibiting a YF wild-type-specific envelope (E) protein epitope are present at low frequency in the vaccine pool and were able to isolate representative virus variants with and without this epitope, designated 17D(+wt) and 17D(-wt), respectively. These variants were employed here in an investigation of YF virus pathogenesis in the mouse model. Both the 17D-204 parent and the 17D(+wt) variant viruses were lethal for adult outbred mice by the intracerebral route of inoculation. However, the 17D(-wt) variant was significantly attenuated (18% mortality rate) and replicated to much lower titer in the brains of infected mice. A single amino acid substitution in the envelope (E) protein at E-240 (Ala-->Val) was identified as responsible for the restricted replication of the 17D(-wt) variant in vivo. The 17D(+wt) variant has an additional second-site mutation, believed to encode a reversion to the neurovirulence phenotype of the 17D-204 parent virus. The amino acid substitution in the E protein at E-173 (Thr-->Ile) of the 17D(+wt) variant which results in the appearance of the wild-type-specific epitope or nucleotide changes in the 5' and 3' noncoding regions of the virus are proposed as a candidates.
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Noor eAhsan
2016-02-01
Full Text Available Rift Valley Fever Virus (RVFV is a RNA virus that belongs to the genus Phlebovirus, family Bunyaviridae. It infects humans and livestock and causes Rift Valley fever. RVFV is considered an agricultural pathogen by the USDA, as it can cause up to 100% abortion in cattle and extensive death of newborns. In addition, it is designated as Category A pathogen by the CDC and the NIAID. In some human cases of RVFV infection, the virus causes fever, ocular damage, liver damage, hemorrhagic fever, and death. There are currently limited options for vaccine candidates, which include the MP-12 and clone 13 versions of RVFV. Viral infections often deregulate multiple cellular pathways that contribute to replication and host pathology. We have previously shown that latent HIV-1 and HTLV-1 infected cells secrete exosomes that contain short viral RNAs, limited number of genomic RNAs, and viral proteins. These exosomes largely target neighboring cells and activate the NF-кB pathway, leading to cell proliferation and overall better viral replication. In this manuscript, we studied the effects of exosome formation from RVFV infected cells and their function on recipient cells. We initially infected cells, isolated resistant clones, and further purified using dilution cloning. We then characterized these cells as resistant to new RVFV infection, but sensitive to other viral infections, including Venezuelan Equine Encephalitis Virus (VEEV. These clones contained normal markers (i.e. CD63 for exosomes and were able to activate the TLR pathway in recipient reporter cells. Interestingly, the exosome rich preparations, much like their host cell, contained viral RNA (L, M, and S genome. The RNAs were detected using qRT-PCR in both parental and exosomal preparations as well as in CD63 immunoprecipitates. Viral proteins such as N and a modified form of NSs were present in some of these exosomes. Finally, treatment of recipient cells (T- cells and monocytic cells showed
Fatal Yellow Fever in Travelers to Brazil, 2018.
Hamer, Davidson H; Angelo, Kristina; Caumes, Eric; van Genderen, Perry J J; Florescu, Simin A; Popescu, Corneliu P; Perret, Cecilia; McBride, Angela; Checkley, Anna; Ryan, Jenny; Cetron, Martin; Schlagenhauf, Patricia
2018-03-23
Yellow fever virus is a mosquito-borne flavivirus that causes yellow fever, an acute infectious disease that occurs in South America and sub-Saharan Africa. Most patients with yellow fever are asymptomatic, but among the 15% who develop severe illness, the case fatality rate is 20%-60%. Effective live-attenuated virus vaccines are available that protect against yellow fever (1). An outbreak of yellow fever began in Brazil in December 2016; since July 2017, cases in both humans and nonhuman primates have been reported from the states of São Paulo, Minas Gerais, and Rio de Janeiro, including cases occurring near large urban centers in these states (2). On January 16, 2018, the World Health Organization updated yellow fever vaccination recommendations for Brazil to include all persons traveling to or living in Espírito Santo, São Paulo, and Rio de Janeiro states, and certain cities in Bahia state, in addition to areas where vaccination had been recommended before the recent outbreak (3). Since January 2018, 10 travel-related cases of yellow fever, including four deaths, have been reported in international travelers returning from Brazil. None of the 10 travelers had received yellow fever vaccination.
Hepatitis C in haemorrhagic obstetrical emergencies
International Nuclear Information System (INIS)
Khaskheli, M.; Baloch, S.
2014-01-01
Objective: To determine the maternal health and fetal outcome in hepatitis C with obstetrical haemorrhagic emergencies. Study Design: An observational study. Place and Duration of Study: Department of Obstetrics and Gynaecology Unit-I, Liaquat University of Medical and Health Sciences Hospital, Hyderabad, Sindh, from January 2009 to December 2010. Methodology: All the women admitted during the study period with different obstetrical haemorrhagic emergencies were included. On virology screening, hepatitis C screening was done on all. The women with non-haemorrhagic obstetrical emergencies were excluded. Studied variables included demographic characteristics, the nature of obstetrical emergency, haemorrhagic conditions and maternal and fetal morbidity and mortality. The data was analyzed on SPSS version 20. Results: More frequent obstetrical haemorrhagic emergencies were observed with hepatitis C positive in comparison with hepatitis C negative cases including post-partum haemorrhage in 292 (80.88%) and ante-partum haemorrhage in 69 (19.11%) cases. Associated morbidities seen were disseminated intravascular coagulation in 43 (11.91%) and shock in 29 (8.03%) cases with hepatitis C positive. Fetal still birth rate was 37 (10.24%) in hepatitis C positive cases. Conclusion: Frequency of maternal morbidity and mortality and perinatal mortality was high in obstetrical haemorrhagic emergencies with hepatitis C positive cases. (author)
Zhang, Yong-Zhen; He, Yong-Wen; Dai, Yong-An; Xiong, Yanwen; Zheng, Han; Zhou, Dun-Jin; Li, Juan; Sun, Qiangzheng; Luo, Xue-Lian; Cheng, Yu-Li; Qin, Xin-Cheng; Tian, Jun-Hua; Chen, Xiao-Ping; Yu, Bin; Jin, Dong; Guo, Wen-Ping; Li, Wei; Wang, Wen; Peng, Jin-Song; Zhang, Guo-Bin; Zhang, Shaomin; Chen, Xiao-Min; Wang, Yan; Li, Ming-Hui; Li, Zhenjun; Lu, Shan; Ye, Changyun; de Jong, Menno D.; Xu, Jianguo
2012-01-01
Background. Hemorrhagic fever-like illness caused by a novel Bunyavirus, Huaiyangshan virus (HYSV, also known as Severe Fever with Thrombocytopenia virus [SFTSV] and Fever, Thrombocytopenia and Leukopenia Syndrome [FTLS]), has recently been described in China. Methods. Patients with
Molecular epidemiology of Crimean-Congo hemorrhagic fever virus in Kosovo.
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Luka Fajs
Full Text Available Crimean-Congo hemorrhagic fever virus (CCHFV is a zoonotic agent that causes severe, life-threatening disease, with a case fatality rate of 10-50%. It is the most widespread tick-borne virus in the world, with cases reported in Africa, Asia and Eastern Europe. CCHFV is a genetically diverse virus. Its genetic diversity is often correlated to its geographical origin. Genetic variability of CCHFV was determined within few endemic areas, however limited data is available for Kosovo. Furthermore, there is little information about the spatiotemporal genetic changes of CCHFV in endemic areas. Kosovo is an important endemic area for CCHFV. Cases were reported each year and the case-fatality rate is significantly higher compared to nearby regions. In this study, we wanted to examine the genetic variability of CCHFV obtained directly from CCHF-confirmed patients, hospitalized in Kosovo from 1991 to 2013. We sequenced partial S segment CCHFV nucleotide sequences from 89 patients. Our results show that several viral variants are present in Kosovo and that the genetic diversity is high in relation to the studied area. We also show that variants are mostly uniformly distributed throughout Kosovo and that limited evolutionary changes have occurred in 22 years. Our results also suggest the presence of a new distinct lineage within the European CCHF phylogenetic clade. Our study provide the largest number of CCHFV nucleotide sequences from patients in 22 year span in one endemic area.
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Renée Zakhia
2018-01-01
Full Text Available West Nile virus (WNV and Rift Valley fever virus (RVFV are two emerging arboviruses transmitted by Culex pipiens species that includes two biotypes: pipiens and molestus. In Lebanon, human cases caused by WNV and RVFV have never been reported. However, the introduction of these viruses in the country is likely to occur through the migratory birds and animal trades. In this study, we evaluated the ability of Cx. pipiens, a predominant mosquito species in urban and rural regions in Lebanon, to transmit WNV and RVFV. Culex egg rafts were collected in the West Bekaa district, east of Lebanon and adult females of Cx. pipiens were experimentally infected with WNV and RVFV Clone 13 strain at titers of 1.6×108 and 1.33×107 plaque forming units (PFU/mL, respectively. We estimated viral infection, dissemination and transmission at 3, 7, 14 and 19 days post infection (dpi. Results showed that infection was higher for WNV than for RVFV from 3 dpi to 19 dpi. Viral dissemination and transmission started from 3 dpi for WNV; and only from 19 dpi for RVFV. Moreover, Cx. pipiens were able to excrete in saliva a higher number of viral particles of WNV (1028 ± 405 PFU/saliva at 19 dpi than RVFV (42 PFU/saliva at 19 dpi. Cx. pipiens from Lebanon are efficient experimental vectors of WNV and to a lower extent, RVFV. These findings should stimulate local authorities to establish an active entomological surveillance in addition to animal surveys for both viruses in the country.
First isolation of dengue virus from the 2010 epidemic in Nepal.
Pandey, Basu D; Nabeshima, Takeshi; Pandey, Kishor; Rajendra, Saroj P; Shah, Yogendra; Adhikari, Bal R; Gupta, Govinda; Gautam, Ishan; Tun, Mya M N; Uchida, Reo; Shrestha, Mahendra; Kurane, Ichiro; Morita, Kouichi
2013-09-01
Dengue is an emerging disease in Nepal and was first observed as an outbreak in nine lowland districts in 2006. In 2010, however, a large epidemic of dengue occurred with 4,529 suspected and 917 serologically-confirmed cases and five deaths reported in government hospitals in Nepal. The collection of demographic information was performed along with an entomological survey and clinical evaluation of the patients. A total of 280 serum samples were collected from suspected dengue patients. These samples were subjected to routine laboratory investigations and IgM-capture ELISA for dengue serological identification, and 160 acute serum samples were used for virus isolation, RT-PCR, sequencing and phylogenetic analysis. The results showed that affected patients were predominately adults, and that 10% of the cases were classified as dengue haemorrhagic fever/ dengue shock syndrome. The genetic characterization of dengue viruses isolated from patients in four major outbreak areas of Nepal suggests that the DENV-1 strain was responsible for the 2010 epidemic. Entomological studies identified Aedes aegypti in all epidemic areas. All viruses belonged to a monophyletic single clade which is phylogenetically close to Indian viruses. The dengue epidemic started in the lowlands and expanded to the highland areas. To our knowledge, this is the first dengue isolation and genetic characterization reported from Nepal.
The untranslated regions of classic swine fever virus RNA trigger apoptosis.
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Wei-Li Hsu
Full Text Available Classical swine fever virus (CSFV causes a broad range of disease in pigs, from acute symptoms including high fever and hemorrhages, to chronic disease or unapparent infection, depending on the virus strain. CSFV belongs to the genus Pestivirus of the family Flaviviridae. It carries a single-stranded positive-sense RNA genome. An internal ribosomal entry site (IRES in the 5' untranslated region (UTR drives the translation of a single open reading frame encoding a 3898 amino acid long polypeptide chain. The open reading frame is followed by a 3' UTR comprising four highly structured stem-loops. In the present study, a synthetic RNA composed of the 5' and 3' UTRs of the CSFV genome devoid of any viral coding sequence and separated by a luciferase gene cassette (designated 5'UTR-Luc-3'UTR triggered apoptotic cell death as early as 4 h post-transfection. The apoptosis was measured by DNA laddering analysis, TUNEL assay, annexin-V binding determined by flow cytometry, and by analysis of caspase activation. Contrasting with this, only trace DNA laddering was observed in cells transfected with the individual 5' or 3' UTR RNA; even when the 5' UTR and 3' UTR were co-transfected as separate RNA molecules, DNA laddering did not reach the level induced by the chimeric 5'UTR-Luc-3'UTR RNA. Interestingly, RNA composed of the 5'UTR and of stem-loop I of the 3'UTR triggered much stronger apoptosis than the 5' or 3'UTR alone. These results indicate that the 5' and 3' UTRs act together in cis induce apoptosis. We furthered obtained evidence that the UTR-mediated apoptosis required double-stranded RNA and involved translation shutoff possibly through activation of PKR.
Coinfection with influenza A(H1N1pdm09 and dengue virus in fatal cases
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Anne Carolinne Bezerra Perdigão
2016-01-01
Full Text Available Abstract We report on four patients with fatal influenza A(H1N1pdm09 and dengue virus coinfections. Clinical, necropsy and histopathologic findings presented in all cases were characteristic of influenza-dengue coinfections, and all were laboratory-confirmed for both infections. The possibility of influenza and dengue coinfection should be considered in locations where these two viruses’ epidemic periods coincide to avoid fatal outcomes. Dengue is a mosquito-borne viral infection caused by one of the four dengue viruses (DENV-1 to 4. Each of these viruses is capable of causing nonspecific febrile illnesses, classic dengue fever and dengue haemorrhagic fever (Gubler 1998. As a result, dengue is often difficult to diagnose clinically, especially because peak dengue season often coincides with that of other common febrile illnesses in tropical regions (Chacon et al. 2015. In April 2009, a new virus, influenza A/H1N1/pandemic (FluA/H1N1/09pdm, caused a severe outbreak in Mexico. The virus quickly spread throughout the world, and in June 2009, the World Health Organization declared a pandemic (WHO 2010. In Brazil, the first laboratory confirmed case of FluA/H1N1/09pdm was in July 2009 (Pires Neto et al. 2013. The state of Ceará, in Northeast Brazil, is a dengue endemic area. In this state, the virus influenza A(H1N1pdm09 has circulated since 2009, and through the first half of 2012, 11 deaths caused by the virus were confirmed (Pires Neto et al. 2013. The influenza and dengue seasons in Ceará overlap, which led to diagnostic difficulties. We report four cases of laboratory-confirmed coinfection of deadly influenza A(H1N1pdm09 with DENV, which occurred during the dengue and influenza season in 2012 and 2013 in Ceará.
Serologic evidence of exposure to Rift Valley fever virus detected in Tunisia
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A. Bosworth
2016-01-01
Full Text Available Rift Valley fever virus (RVFv is capable of causing dramatic outbreaks amongst economically important animal species and is capable of causing severe symptoms and mortality in humans. RVFv is known to circulate widely throughout East Africa; serologic evidence of exposure has also been found in some northern African countries, including Mauritania. This study aimed to ascertain whether RVFv is circulating in regions beyond its known geographic range. Samples from febrile patients (n=181 and nonfebrile healthy agricultural and slaughterhouse workers (n=38 were collected during the summer of 2014 and surveyed for exposure to RVFv by both serologic tests and PCR. Of the 219 samples tested, 7.8% of nonfebrile participants showed immunoglobulin G reactivity to RVFv nucleoprotein and 8.3% of febrile patients showed immunoglobulin M reactivity, with the latter samples indicating recent exposure to the virus. Our results suggest an active circulation of RVFv and evidence of human exposure in the population of Tunisia.
How Ebola virus counters the interferon system.
Kühl, A; Pöhlmann, S
2012-09-01
Zoonotic transmission of Ebola virus (EBOV) to humans causes a severe haemorrhagic fever in afflicted individuals with high case-fatality rates. Neither vaccines nor therapeutics are at present available to combat EBOV infection, making the virus a potential threat to public health. To devise antiviral strategies, it is important to understand which components of the immune system could be effective against EBOV infection. The interferon (IFN) system constitutes a key innate defence against viral infections and prevents development of lethal disease in mice infected with EBOV strains not adapted to this host. Recent research revealed that expression of the host cell IFN-inducible transmembrane proteins 1-3 (IFITM1-3) and tetherin is induced by IFN and restricts EBOV infection, at least in cell culture model systems. IFITMs, tetherin and other effector molecules of the IFN system could thus pose a potent barrier against EBOV spread in humans. However, EBOV interferes with signalling events required for human cells to express these proteins. Here, we will review the strategies employed by EBOV to fight the IFN system, and we will discuss how IFITM proteins and tetherin inhibit EBOV infection. © 2012 Blackwell Verlag GmbH.
International travel between global urban centres vulnerable to yellow fever transmission.
Brent, Shannon E; Watts, Alexander; Cetron, Martin; German, Matthew; Kraemer, Moritz Ug; Bogoch, Isaac I; Brady, Oliver J; Hay, Simon I; Creatore, Maria I; Khan, Kamran
2018-05-01
To examine the potential for international travel to spread yellow fever virus to cities around the world. We obtained data on the international flight itineraries of travellers who departed yellow fever-endemic areas of the world in 2016 for cities either where yellow fever was endemic or which were suitable for viral transmission. Using a global ecological model of dengue virus transmission, we predicted the suitability of cities in non-endemic areas for yellow fever transmission. We obtained information on national entry requirements for yellow fever vaccination at travellers' destination cities. In 2016, 45.2 million international air travellers departed from yellow fever-endemic areas of the world. Of 11.7 million travellers with destinations in 472 cities where yellow fever was not endemic but which were suitable for virus transmission, 7.7 million (65.7%) were not required to provide proof of vaccination upon arrival. Brazil, China, India, Mexico, Peru and the United States of America had the highest volumes of travellers arriving from yellow fever-endemic areas and the largest populations living in cities suitable for yellow fever transmission. Each year millions of travellers depart from yellow fever-endemic areas of the world for cities in non-endemic areas that appear suitable for viral transmission without having to provide proof of vaccination. Rapid global changes in human mobility and urbanization make it vital for countries to re-examine their vaccination policies and practices to prevent urban yellow fever epidemics.
Yellow fever vaccine-associated neurological disease, a suspicious case.
Beirão, Pedro; Pereira, Patrícia; Nunes, Andreia; Antunes, Pedro
2017-03-02
A 70-year-old man with known cardiovascular risk factors, presented with acute onset expression aphasia, agraphia, dyscalculia, right-left disorientation and finger agnosia, without fever or meningeal signs. Stroke was thought to be the cause, but cerebrovascular disease investigation was negative. Interviewing the family revealed he had undergone yellow fever vaccination 18 days before. Lumbar puncture revealed mild protein elevation. Cultural examinations, Coxiella burnetti, and neurotropic virus serologies were negative. Regarding the yellow fever virus, IgG was identified in serum and cerebrospinal fluid (CSF), with negative IgM and virus PCR in CSF. EEG showed an encephalopathic pattern. The patient improved gradually and a week after discharge was his usual self. Only criteria for suspect neurotropic disease were met, but it's possible the time spent between symptom onset and lumbar puncture prevented a definite diagnosis of yellow fever vaccine-associated neurological disease. This gap would have been smaller if the vaccination history had been collected earlier. 2017 BMJ Publishing Group Ltd.
Tabachnick, W J; Wallis, G P; Aitken, T H; Miller, B R; Amato, G D; Lorenz, L; Powell, J R; Beaty, B J
1985-11-01
Twenty-eight populations representing a worldwide distribution of Aedes aegypti were tested for their ability to become orally infected with yellow fever virus (YFV). Populations had been analyzed for genetic variations at 11 isozyme loci and assigned to one of 8 genetic geographic groups of Ae. aegypti. Infection rates suggest that populations showing isozyme genetic relatedness also demonstrate similarity to oral infection rates with YFV. The findings support the hypothesis that genetic variation exists for oral susceptibility to YFV in Ae. aegypti.
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Galler R.
1997-01-01
Full Text Available The yellow fever (YF virus is the prototype flavivirus. The use of molecular techniques has unraveled the basic mechanisms of viral genome structure and expression. Recent trends in flavivirus research include the use of infectious clone technology with which it is possible to recover virus from cloned cDNA. Using this technique, mutations can be introduced at any point of the viral genome and their resulting effect on virus phenotype can be assessed. This approach has opened new possibilities to study several biological viral features with special emphasis on the issue of virulence/attenuation of the YF virus. The feasibility of using YF virus 17D vaccine strain, for which infectious cDNA is available, as a vector for the expression of heterologous antigens is reviewed
Animal Models for the Study of Rodent-Borne Hemorrhagic Fever Viruses: Arenaviruses and Hantaviruses
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Joseph W. Golden
2015-01-01
Full Text Available Human pathogenic hantaviruses and arenaviruses are maintained in nature by persistent infection of rodent carrier populations. Several members of these virus groups can cause significant disease in humans that is generically termed viral hemorrhagic fever (HF and is characterized as a febrile illness with an increased propensity to cause acute inflammation. Human interaction with rodent carrier populations leads to infection. Arenaviruses are also viewed as potential biological weapons threat agents. There is an increased interest in studying these viruses in animal models to gain a deeper understating not only of viral pathogenesis, but also for the evaluation of medical countermeasures (MCM to mitigate disease threats. In this review, we examine current knowledge regarding animal models employed in the study of these viruses. We include analysis of infection models in natural reservoirs and also discuss the impact of strain heterogeneity on the susceptibility of animals to infection. This information should provide a comprehensive reference for those interested in the study of arenaviruses and hantaviruses not only for MCM development but also in the study of viral pathogenesis and the biology of these viruses in their natural reservoirs.
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Ziying Han
2015-10-01
Full Text Available Hemorrhagic fever viruses, including the filoviruses (Ebola and Marburg and arenaviruses (Lassa and Junín viruses, are serious human pathogens for which there are currently no FDA approved therapeutics or vaccines. Importantly, transmission of these viruses, and specifically late steps of budding, critically depend upon host cell machinery. Consequently, strategies which target these mechanisms represent potential targets for broad spectrum host oriented therapeutics. An important cellular signal implicated previously in EBOV budding is calcium. Indeed, host cell calcium signals are increasingly being recognized to play a role in steps of entry, replication, and transmission for a range of viruses, but if and how filoviruses and arenaviruses mobilize calcium and the precise stage of virus transmission regulated by calcium have not been defined. Here we demonstrate that expression of matrix proteins from both filoviruses and arenaviruses triggers an increase in host cytoplasmic Ca2+ concentration by a mechanism that requires host Orai1 channels. Furthermore, we demonstrate that Orai1 regulates both VLP and infectious filovirus and arenavirus production and spread. Notably, suppression of the protein that triggers Orai activation (Stromal Interaction Molecule 1, STIM1 and genetic inactivation or pharmacological blockade of Orai1 channels inhibits VLP and infectious virus egress. These findings are highly significant as they expand our understanding of host mechanisms that may broadly control enveloped RNA virus budding, and they establish Orai and STIM1 as novel targets for broad-spectrum host-oriented therapeutics to combat these emerging BSL-4 pathogens and potentially other enveloped RNA viruses that bud via similar mechanisms.
Emergence of a new lagovirus related to rabbit haemorrhagic disease virus
Le Gall-Recule, Ghislaine; Lavazza, Antonio; Marchandeau, Stephane; Bertagnoli, Stéphane; Zwingelstein, Francoise; Cavadini, Patrizia; Martinelli, Nicola; Lombardi, Guerino; Guérin, Jean-Luc; Lemaitre, Evelyne; Decors, Anouk; Boucher, Samuel; Le Normand, Bernadette; Capucci, Lorenzo
2013-01-01
Since summer 2010, numerous cases of Rabbit Haemorrhagic Disease (RHD) have been reported in north-western France both in rabbitries, affecting RHD-vaccinated rabbits, and in wild populations. We demonstrate that the aetiological agent was a lagovirus phylogenetically distinct from other lagoviruses and which presents a unique antigenic profile. Experimental results show that the disease differs from RHD in terms of disease duration, mortality rates, higher occurrence of subacute/chronic form...
Carvalho, Carina Luísa; Silva, Sara; Gouveia, Paz; Costa, Margarida; Duarte, Elsa Leclerc; Henriques, Ana Margarida; Barros, Sílvia Santos; Luís, Tiago; Ramos, Fernanda; Fagulha, Teresa; Fevereiro, Miguel; Duarte, Margarida Dias
2017-12-01
We report the detection of rabbit haemorrhagic disease virus 2 (RHDV2) in the Madeira archipelago, Portugal. Viral circulation was confirmed by RT-qPCR and vp60 sequencing. Epidemiological data revealed the outbreak initiated in October 2016 in Porto Santo affecting wild and domestic rabbits. It was then detected three months later on the island of Madeira. Five haplotypes were identified and a genetic overall similarity of 99.54 to 99.89% was observed between the two viral populations. Unique single nucleotide polymorphisms were recognised in the Madeira archipelago strains, two of which resulting in amino acid substitutions at positions 480 and 570 in the VP60 protein. Phylogenetic investigation by Maximum Likelihood showed all the vp60 sequences from the Madeira archipelago group together with high bootstraps. The analysis also showed that the Madeira archipelago strains are closely related to the strains detected in the south of mainland Portugal in 2016, suggesting a possible introduction from the mainland. The epidemiological data and high genetic similarity indicate a common source for the Porto Santo and Madeira RHDV2 outbreaks. Human activity related to hunting was most probably at the origin of the Madeira outbreak.
Neurovirulence of yellow fever 17DD vaccine virus to rhesus monkeys
International Nuclear Information System (INIS)
Marchevsky, Renato S.; Freire, Marcos S.; Coutinho, Evandro S.F.; Galler, Ricardo
2003-01-01
The yellow fever 17D virus is attenuated and used for human vaccination. Two of its substrains, 17D-204 and 17DD, are used for vaccine production. One of the remarkable properties of this vaccine is limited viral replication in the host but with significant dissemination of the viral mass, yielding a robust and long-lived neutralizing antibody response. The vaccine has excellent records of efficacy and safety and is cheap, used as a single dose, and there are well-established production methodology and quality control procedures which include the monkey neurovirulence test (MNTV). The present study aims at a better understanding of YF 17DD virus attenuation and immunogenicity in the MNVT with special emphasis on viremia, seroconversion, clinical and histological lesions scores, and their intrinsic variability across the tests. Several MNVTs were performed using the secondary seed lot virus 17DD 102/84 totaling 49 rhesus monkeys. Viremia was never higher than the accepted limits established in international requirements, and high levels of neutralizing antibodies were observed in all animals. None of the animals showed visceral lesions. We found that the clinical scores for the same virus varied widely across the tests. There was a direct correlation between the clinical scores in animals with clinical signs of encephalitis and a higher degree of central nervous system (CNS) histological lesions, with an increase of lesions in areas of the CNS such as the substantia nigra, nucleus caudatus, intumescentia cervicalis, and intumescentia ventralis. The histological scores were shown to be less prone to individual variations and had a more homogeneous value distribution among the tests. Since 17DD 102/84 seed virus has been used for human vaccine production and immunization for 16 years with the vaccine being safe and efficacious, it demonstrates that the observed variations across the MNVTs do not influence its effect on humans
Kraemer, Moritz U G; Faria, Nuno R; Reiner, Robert C; Golding, Nick; Nikolay, Birgit; Stasse, Stephanie; Johansson, Michael A; Salje, Henrik; Faye, Ousmane; Wint, G R William; Niedrig, Matthias; Shearer, Freya M; Hill, Sarah C; Thompson, Robin N; Bisanzio, Donal; Taveira, Nuno; Nax, Heinrich H; Pradelski, Bary S R; Nsoesie, Elaine O; Murphy, Nicholas R; Bogoch, Isaac I; Khan, Kamran; Brownstein, John S; Tatem, Andrew J; de Oliveira, Tulio; Smith, David L; Sall, Amadou A; Pybus, Oliver G; Hay, Simon I; Cauchemez, Simon
2017-03-01
Since late 2015, an epidemic of yellow fever has caused more than 7334 suspected cases in Angola and the Democratic Republic of the Congo, including 393 deaths. We sought to understand the spatial spread of this outbreak to optimise the use of the limited available vaccine stock. We jointly analysed datasets describing the epidemic of yellow fever, vector suitability, human demography, and mobility in central Africa to understand and predict the spread of yellow fever virus. We used a standard logistic model to infer the district-specific yellow fever virus infection risk during the course of the epidemic in the region. The early spread of yellow fever virus was characterised by fast exponential growth (doubling time of 5-7 days) and fast spatial expansion (49 districts reported cases after only 3 months) from Luanda, the capital of Angola. Early invasion was positively correlated with high population density (Pearson's r 0·52, 95% CI 0·34-0·66). The further away locations were from Luanda, the later the date of invasion (Pearson's r 0·60, 95% CI 0·52-0·66). In a Cox model, we noted that districts with higher population densities also had higher risks of sustained transmission (the hazard ratio for cases ceasing was 0·74, 95% CI 0·13-0·92 per log-unit increase in the population size of a district). A model that captured human mobility and vector suitability successfully discriminated districts with high risk of invasion from others with a lower risk (area under the curve 0·94, 95% CI 0·92-0·97). If at the start of the epidemic, sufficient vaccines had been available to target 50 out of 313 districts in the area, our model would have correctly identified 27 (84%) of the 32 districts that were eventually affected. Our findings show the contributions of ecological and demographic factors to the ongoing spread of the yellow fever outbreak and provide estimates of the areas that could be prioritised for vaccination, although other constraints such as vaccine
Marchandeau, S; Bertagnoli, S; Peralta, B; Boucraut-Baralon, C; Letty, J; Reitz, F
2004-11-06
Serological data on myxoma virus, rabbit haemorrhagic disease (RHD) virus and RHD-like viruses in juvenile rabbits (Oryctolagus cuniculus) trapped in 1995, 1996 and 1997 in two areas of France were analysed. For each disease, the effects of bodyweight, year, month and seropositivity for the other disease were modelled by using logistic regressions. In one area, a model including RHD seropositivity was selected to explain the myxoma virus seropositivity. Models including myxoma virus seropositivity were selected to explain the RHD seropositivity in both areas, and the odds of a rabbit being seropositive to both viruses were 5.1 and 8.4 times higher than the odds of a rabbit being seronegative to myxoma virus and seropositive to RHD. The year and bodyweight had significant effects for myxomatosis in one area and for RHD in both areas.
Rift Valley fever virus infection in golden Syrian hamsters.
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Dionna Scharton
Full Text Available Rift Valley fever virus (RVFV is a formidable pathogen that causes severe disease and abortion in a variety of livestock species and a range of disease in humans that includes hemorrhagic fever, fulminant hepatitis, encephalitis and blindness. The natural transmission cycle involves mosquito vectors, but exposure can also occur through contact with infected fluids and tissues. The lack of approved antiviral therapies and vaccines for human use underlies the importance of small animal models for proof-of-concept efficacy studies. Several mouse and rat models of RVFV infection have been well characterized and provide useful systems for the study of certain aspects of pathogenesis, as well as antiviral drug and vaccine development. However, certain host-directed therapeutics may not act on mouse or rat pathways. Here, we describe the natural history of disease in golden Syrian hamsters challenged subcutaneously with the pathogenic ZH501 strain of RVFV. Peracute disease resulted in rapid lethality within 2 to 3 days of RVFV challenge. High titer viremia and substantial viral loads were observed in most tissues examined; however, histopathology and immunostaining for RVFV antigen were largely restricted to the liver. Acute hepatocellular necrosis associated with a strong presence of viral antigen in the hepatocytes indicates that fulminant hepatitis is the likely cause of mortality. Further studies to assess the susceptibility and disease progression following respiratory route exposure are warranted. The use of the hamsters to model RVFV infection is suitable for early stage antiviral drug and vaccine development studies.
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Galler R.
2005-01-01
Full Text Available A chimeric yellow fever (YF-dengue serotype 2 (dengue 2 virus was constructed by replacing the premembrane and envelope genes of the YF 17D virus with those from dengue 2 virus strains of Southeast Asian genotype. The virus grew to high titers in Vero cells and, after passage 2, was used for immunogenicity and attenuation studies in rhesus monkeys. Subcutaneous immunization of naive rhesus monkeys with the 17D-D2 chimeric virus induced a neutralizing antibody response associated with the protection of 6 of 7 monkeys against viremia by wild-type dengue 2 virus. Neutralizing antibody titers to dengue 2 were significantly lower in YF-immune animals than in YF-naive monkeys and protection against challenge with wild-type dengue 2 virus was observed in only 2 of 11 YF-immune monkeys. An anamnestic response to dengue 2, indicated by a sharp increase of neutralizing antibody titers, was observed in the majority of the monkeys after challenge with wild-type virus. Virus attenuation was demonstrated using the standard monkey neurovirulence test. The 17D-D2 chimera caused significantly fewer histological lesions than the YF 17DD virus. The attenuated phenotype could also be inferred from the limited viremias compared to the YF 17DD vaccine. Overall, these results provide further support for the use of chimeric viruses for the development of a new live tetravalent dengue vaccine.
Bárcena, Juan; Guerra, Beatriz; Angulo, Iván; González, Julia; Valcárcel, Félix; Mata, Carlos P.; Castón, José R.; Blanco, Esther; Alejo, Alí
2015-01-01
International audience; In 2010 a new Lagovirus related to rabbit haemorrhagic disease virus (RHDV) emerged in France and has since rapidly spread throughout domestic and wild rabbit populations of several European countries. The new virus, termed RHDV2, exhibits distinctive genetic, antigenic and pathogenic features. Notably, RHDV2 kills rabbits previously vaccinated with RHDV vaccines. Here we report for the first time the generation and characterization of RHDV2-specific virus-like particl...
Rapid molecular assays for the detection of yellow fever virus in low-resource settings.
Escadafal, Camille; Faye, Oumar; Sall, Amadou Alpha; Faye, Ousmane; Weidmann, Manfred; Strohmeier, Oliver; von Stetten, Felix; Drexler, Josef; Eberhard, Michael; Niedrig, Matthias; Patel, Pranav
2014-03-01
Yellow fever (YF) is an acute viral hemorrhagic disease transmitted by Aedes mosquitoes. The causative agent, the yellow fever virus (YFV), is found in tropical and subtropical areas of South America and Africa. Although a vaccine is available since the 1930s, YF still causes thousands of deaths and several outbreaks have recently occurred in Africa. Therefore, rapid and reliable diagnostic methods easy to perform in low-resources settings could have a major impact on early detection of outbreaks and implementation of appropriate response strategies such as vaccination and/or vector control. The aim of this study was to develop a YFV nucleic acid detection method applicable in outbreak investigations and surveillance studies in low-resource and field settings. The method should be simple, robust, rapid and reliable. Therefore, we adopted an isothermal approach and developed a recombinase polymerase amplification (RPA) assay which can be performed with a small portable instrument and easy-to-use lyophilized reagents. The assay was developed in three different formats (real-time with or without microfluidic semi-automated system and lateral-flow assay) to evaluate their application for different purposes. Analytical specificity and sensitivity were evaluated with a wide panel of viruses and serial dilutions of YFV RNA. Mosquito pools and spiked human plasma samples were also tested for assay validation. Finally, real-time RPA in portable format was tested under field conditions in Senegal. The assay was able to detect 20 different YFV strains and demonstrated no cross-reactions with closely related viruses. The RPA assay proved to be a robust, portable method with a low detection limit (<21 genome equivalent copies per reaction) and rapid processing time (<20 min). Results from real-time RPA field testing were comparable to results obtained in the laboratory, thus confirming our method is suitable for YFV detection in low-resource settings.
Rapid molecular assays for the detection of yellow fever virus in low-resource settings.
Directory of Open Access Journals (Sweden)
Camille Escadafal
2014-03-01
Full Text Available BACKGROUND: Yellow fever (YF is an acute viral hemorrhagic disease transmitted by Aedes mosquitoes. The causative agent, the yellow fever virus (YFV, is found in tropical and subtropical areas of South America and Africa. Although a vaccine is available since the 1930s, YF still causes thousands of deaths and several outbreaks have recently occurred in Africa. Therefore, rapid and reliable diagnostic methods easy to perform in low-resources settings could have a major impact on early detection of outbreaks and implementation of appropriate response strategies such as vaccination and/or vector control. METHODOLOGY: The aim of this study was to develop a YFV nucleic acid detection method applicable in outbreak investigations and surveillance studies in low-resource and field settings. The method should be simple, robust, rapid and reliable. Therefore, we adopted an isothermal approach and developed a recombinase polymerase amplification (RPA assay which can be performed with a small portable instrument and easy-to-use lyophilized reagents. The assay was developed in three different formats (real-time with or without microfluidic semi-automated system and lateral-flow assay to evaluate their application for different purposes. Analytical specificity and sensitivity were evaluated with a wide panel of viruses and serial dilutions of YFV RNA. Mosquito pools and spiked human plasma samples were also tested for assay validation. Finally, real-time RPA in portable format was tested under field conditions in Senegal. CONCLUSION/SIGNIFICANCE: The assay was able to detect 20 different YFV strains and demonstrated no cross-reactions with closely related viruses. The RPA assay proved to be a robust, portable method with a low detection limit (<21 genome equivalent copies per reaction and rapid processing time (<20 min. Results from real-time RPA field testing were comparable to results obtained in the laboratory, thus confirming our method is suitable for
[Crimean-Congo hemorrhagic fever].
Saijo, Masayuki; Moriikawa, Shigeru; Kurane, Ichiro
2004-12-01
Crimean-Congo hemorrhagic fever (CCHF) is an acute infectious disease caused by CCHF virus (CCHFV), a member of the family Bunyaviridae, genus Nairovirus. The case fatality rate of CCHF ranges from 10-40%. Because CCHF is not present in Japan, many Japanese virologists and clinicians are not very familiar with this disease. However, there remains the possibility of an introduction of CCHFV or other hemorrhagic fever viruses into Japan from surrounding endemic areas. Development of diagnostic laboratory capacity for viral hemorrhagic fevers is necessary even in countries without these diseases. At the National Institute of Infectious Diseases, Tokyo, Japan, laboratory-based systems such as recombinant protein-based antibody detection, antigen-capture and pathological examination have been developed. In this review article, epidemiologic and clinical data on CCHF in the Xinjiang Uygur Autonomous Region, compiled through field investigations and diagnostic testing utilizing the aforementioned laboratory systems, are presented. CCHFV infections are closely associated with the environmental conditions, life styles, religion, occupation, and human economic activities. Based on these data, preventive measures for CCHFV infections are also discussed.
DEFF Research Database (Denmark)
Boklund, Anette; Goldbach, Stine G.; Uttenthal, Åse
2008-01-01
of CSFV between the hypothetical wild-boar population and the domestic population. Furthermore, the economic impact is assessed taking the perspective of the Danish national budget and the Danish pig industry. We used InterSpreadPlus to model the differential classical swine fever (CSF) risk due to wild......Denmark has no free-range wild-boar population. However, Danish wildlife organizations have suggested that wild boar should be reintroduced into the wild to broaden national biodiversity. Danish pig farmers fear that this would lead to a higher risk of introduction of classical swine fever virus...
Transfusion-related transmission of yellow fever vaccine virus--California, 2009.
2010-01-22
In the United States, yellow fever (YF) vaccination is recommended for travelers and active duty military members visiting endemic areas of sub-Saharan Africa and Central/South America. The American Red Cross recommends that recipients of YF vaccine defer blood product donation for 2 weeks because of the theoretical risk for transmission from a viremic donor. On April 10, 2009, a hospital blood bank supervisor learned that, on March 27, blood products had been collected from 89 U.S. active duty trainees who had received YF vaccine 4 days before donation. This report summarizes the subsequent investigation by the hospital and CDC to identify lapses in donor deferral and to determine whether transfusion-related transmission of YF vaccine virus occurred. The investigation found that a recent change in the timing of trainee vaccination had occurred and that vaccinees had not reported recent YF vaccination status at time of donation. Despite a prompt recall, six units of blood products were transfused into five patients. No clinical evidence or laboratory abnormalities consistent with a serious adverse reaction were identified in four recipients within the first month after transfusion; the fifth patient, who had prostate cancer and end-stage, transfusion-dependent, B-cell lymphoma, died while in hospice care. Three of the four surviving patients had evidence of serologic response to YF vaccine virus. This report provides evidence that transfusion-related transmission of YF vaccine virus can occur and underscores the need for careful screening and deferral of recently vaccinated blood donors.
Wu, Wei; Zhang, Shuo; Qu, Jing; Zhang, Quanfu; Li, Chuan; Li, Jiandong; Jin, Cong; Liang, Mifang; Li, Dexin
2014-07-17
Viral hemorrhagic fevers (VHFs) are worldwide diseases caused by several kinds of viruses. With the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of VHFs. Based on Luminex xMAP technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (HFVs) specific IgG antibodies was developed. Recombinant antigens of nine HFVs including Hantaan virus (HTNV), Seoul virus (SEOV), Puumala virus (PUUV), Andes virus (ANDV), Sin Nombre virus (SNV), Crimean-Congo hemorrhagic fever virus (CCHFV), Rift Valley fever virus (RVFV), Severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) and dengue virus (DENV) were produced and purified from a prokaryotic expression system and the influence of the coupling amount was investigated. Cross-reactions among antigens and their rabbit immune sera were evaluated. Serum samples collected from 51 laboratory confirmed hemorrhagic fever with renal syndrome (HFRS) patients, 43 confirmed SFTS patients and 88 healthy donors were analyzed. Results showed that recombinant nucleocapsid protein of the five viruses belonging to the genus Hantavirus, had serological cross-reactivity with their corresponding rabbit immune sera, but not apparent with immune sera of other four viruses. Evaluation of this new method with clinical serum samples showed 98.04% diagnostic sensitivity for HFRS, 90.70% for SFTS detection and the specificity was ranging from 66.67% to 100.00%. The multiplexed Luminex-based immunoassay has firstly been established in our study, which provides a potentially reliable diagnostic tool for IgG antibody detection of VHFs. Copyright © 2014 Elsevier B.V. All rights reserved.
Immunological features underlying viral hemorrhagic fevers.
Messaoudi, Ilhem; Basler, Christopher F
2015-10-01
Several enveloped RNA viruses of the arenavirus, bunyavirus, filovirus and flavivirus families are associated with a syndrome known as viral hemorrhagic fever (VHF). VHF is characterized by fever, vascular leakage, coagulation defects and multi organ system failure. VHF is currently viewed as a disease precipitated by viral suppression of innate immunity, which promotes systemic virus replication and excessive proinflammatory cytokine responses that trigger the manifestations of severe disease. However, the mechanisms by which immune dysregulation contributes to disease remain poorly understood. Infection of nonhuman primates closely recapitulates human VHF, notably Ebola and yellow fever, thereby providing excellent models to better define the immunological basis for this syndrome. Here we review the current state of our knowledge and suggest future directions that will better define the immunological mechanisms underlying VHF. Copyright © 2015 Elsevier Ltd. All rights reserved.
Yellow Fever 17DD Vaccine Virus Infection Causes Detectable Changes in Chicken Embryos.
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Pedro Paulo de Abreu Manso
Full Text Available The yellow fever (YF 17D vaccine is one of the most effective human vaccines ever created. The YF vaccine has been produced since 1937 in embryonated chicken eggs inoculated with the YF 17D virus. Yet, little information is available about the infection mechanism of YF 17DD virus in this biological model. To better understand this mechanism, we infected embryos of Gallus gallus domesticus and analyzed their histopathology after 72 hours of YF infection. Some embryos showed few apoptotic bodies in infected tissues, suggesting mild focal infection processes. Confocal and super-resolution microscopic analysis allowed us to identify as targets of viral infection: skeletal muscle cells, cardiomyocytes, nervous system cells, renal tubular epithelium, lung parenchyma, and fibroblasts associated with connective tissue in the perichondrium and dermis. The virus replication was heaviest in muscle tissues. In all of these specimens, RT-PCR methods confirmed the presence of replicative intermediate and genomic YF RNA. This clearer characterization of cell targets in chicken embryos paves the way for future development of a new YF vaccine based on a new cell culture system.
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Paul J Wichgers Schreur
2016-03-01
Full Text Available Rift Valley fever virus (RVFV is transmitted among susceptible animals by mosquito vectors. Although the virus can be isolated from nasal and oral swabs of infected animals and is known to be highly infectious when administered experimentally via oral or respiratory route, horizontal transmission of the virus is only sporadically reported in literature. We considered that immunosuppression resulting from stressful conditions in the field may increase the susceptibility to horizontally transmitted RVFV. Additionally, we reasoned that horizontal transmission may induce immune responses that could affect the susceptibility of contact-exposed animals to subsequent infection via mosquito vectors. To address these two hypotheses, viremic lambs were brought into contact with sentinel lambs. One group of sentinel lambs was treated with the immunosuppressive synthetic glucocorticosteroid dexamethasone and monitored for signs of disease and presence of virus in the blood and target organs. Another group of contact-exposed sentinel lambs remained untreated for three weeks and was subsequently challenged with RVFV. We found that none of the dexamethasone-treated contact-exposed lambs developed detectable viremia, antibody responses or significant increases in cytokine mRNA levels. Susceptibility of immunocompetent lambs to RVFV infection was not influenced by previous contact-exposure. Our results are discussed in light of previous findings.
Lassa fever – full recovery without ribavarin treatment: a case report ...
African Journals Online (AJOL)
Her close contacts showed no evidence of Lassa virus infection. Conclusion: This report adds to the literature on the natural history of Lassa fever; and that individuals may survive Lassa fever with conservative management of symptoms of the disease and its complications. Keywords: Lassa fever; viral hemorrhagic fever, ...
Bonaldo, Myrna C.; Garratt, Richard C.; Marchevsky, Renato S.; Coutinho, Evandro S. F.; Jabor, Alfredo V.; Almeida, Luís F. C.; Yamamura, Anna M. Y.; Duarte, Adriana S.; Oliveira, Prisciliana J.; Lizeu, Jackeline O. P.; Camacho, Luiz A. B.; Freire, Marcos S.; Galler, Ricardo
2005-01-01
The yellow fever (YF) 17D vaccine is a live attenuated virus. Three-dimensional (3D) homology modeling of the E protein structure from YF 17D virus and its comparison with that from tick-borne encephalitis virus revealed that it is possible to accommodate inserts of different sizes and amino acid compositions in the flavivirus E protein fg loop. This is consistent with the 3D structures of both the dimeric and trimeric forms in which the fg loop lies exposed to solvents. We demonstrate here that YF 17D viruses bearing foreign humoral (17D/8) and T-cell (17D/13) epitopes, which vary in sequence and length, displayed growth restriction. It is hypothesized that interference with the dimer-trimer transition and with the formation of a ring of such trimers in order to allow fusion compromises the capability of the E protein to induce fusion of viral and endosomal membranes, and a slower rate of fusion may delay the extent of virus production. This would account for the lower levels of replication in cultured cells and of viremia in monkeys, as well as for the more attenuated phenotype of the recombinant viruses in monkeys. Testing of both recombinant viruses (17D/8 and 17D/13) for monkey neurovirulence also suggests that insertion at the 17D E protein fg loop does not compromise the attenuated phenotype of YF 17D virus, further confirming the potential use of this site for the development of new live attenuated 17D virus-based vaccines. PMID:15956601
Vos, de C.J.; Saatkamp, H.W.; Huirne, R.B.M.; Dijkhuizen, A.A.
2003-01-01
Recent classical swine fever (CSF) epidemics in the European Union (EU) have clearly shown that preventing the introduction of CSF virus (CSFV) deserves high priority. Insight into all the factors contributing to the risk of CSFV introduction is a prerequisite for deciding which preventive actions
Gowen, Brian B; Westover, Jonna B; Sefing, Eric J; Bailey, Kevin W; Nishiyama, Shoko; Wandersee, Luci; Scharton, Dionna; Jung, Kie-Hoon; Ikegami, Tetsuro
2015-01-01
Rift Valley fever virus (RVFV; Bunyaviridae, Phlebovirus) causes a range of illnesses that include retinitis, fulminant hepatitis, neurologic disease, and hemorrhagic fever. In hospitalized individuals, case fatality rates can be as high as 10-20%. There are no vaccines or antivirals approved for human use to prevent or treat severe RVFV infections. We previously tested the efficacy of the MP-12 vaccine strain and related variants with NSs truncations as a post-exposure prophylaxis in mice infected with wild-type pathogenic RVFV strain ZH501. Post-exposure efficacy of the rMP12-C13type, a recombinant MP-12 vaccine virus which encodes an in-frame truncation removing 69% of the NSs protein, resulted in 30% survival when administering the virus within 30 min of subcutaneous ZH501 challenge in mice, while the parental MP-12 virus conferred no protection by post-exposure vaccination. Here, we demonstrate uniform protection of hamsters by post-exposure vaccination with rMP12-C13type administered 6 h post-ZH501 infection while no efficacy was observed with the parental MP-12 virus. Notably, both the MP-12 and rMP12-C13type viruses were highly effective (100% protection) when administered 21 days prior to challenge. In a subsequent study delaying vaccination until 8, 12, and 24 h post-RVFV exposure, we observed 80, 70, and 30% survival, respectively. Our findings indicate that the rapid protective innate immune response elicited by rMP12-C13type may be due to the truncated NSs protein, suggesting that the resulting functional inactivation of NSs plays an important role in the observed post-exposure efficacy. Taken together, the data demonstrate that post-exposure vaccination with rMP12-C13type is effective in limiting ZH501 replication and associated disease in standard pre-exposure vaccination and post-challenge treatment models of RVFV infection, and suggest an extended post-exposure prophylaxis window beyond that initially observed in mice.
Caì, Yíngyún; Postnikova, Elena N; Bernbaum, John G; Yú, Shu Qìng; Mazur, Steven; Deiuliis, Nicole M; Radoshitzky, Sheli R; Lackemeyer, Matthew G; McCluskey, Adam; Robinson, Phillip J; Haucke, Volker; Wahl-Jensen, Victoria; Bailey, Adam L; Lauck, Michael; Friedrich, Thomas C; O'Connor, David H; Goldberg, Tony L; Jahrling, Peter B; Kuhn, Jens H
2015-01-01
Simian hemorrhagic fever virus (SHFV) causes a severe and almost uniformly fatal viral hemorrhagic fever in Asian macaques but is thought to be nonpathogenic for humans. To date, the SHFV life cycle is almost completely uncharacterized on the molecular level. Here, we describe the first steps of the SHFV life cycle. Our experiments indicate that SHFV enters target cells by low-pH-dependent endocytosis. Dynamin inhibitors, chlorpromazine, methyl-β-cyclodextrin, chloroquine, and concanamycin A dramatically reduced SHFV entry efficiency, whereas the macropinocytosis inhibitors EIPA, blebbistatin, and wortmannin and the caveolin-mediated endocytosis inhibitors nystatin and filipin III had no effect. Furthermore, overexpression and knockout study and electron microscopy results indicate that SHFV entry occurs by a dynamin-dependent clathrin-mediated endocytosis-like pathway. Experiments utilizing latrunculin B, cytochalasin B, and cytochalasin D indicate that SHFV does not hijack the actin polymerization pathway. Treatment of target cells with proteases (proteinase K, papain, α-chymotrypsin, and trypsin) abrogated entry, indicating that the SHFV cell surface receptor is a protein. Phospholipases A2 and D had no effect on SHFV entry. Finally, treatment of cells with antibodies targeting CD163, a cell surface molecule identified as an entry factor for the SHFV-related porcine reproductive and respiratory syndrome virus, diminished SHFV replication, identifying CD163 as an important SHFV entry component. Simian hemorrhagic fever virus (SHFV) causes highly lethal disease in Asian macaques resembling human illness caused by Ebola or Lassa virus. However, little is known about SHFV's ecology and molecular biology and the mechanism by which it causes disease. The results of this study shed light on how SHFV enters its target cells. Using electron microscopy and inhibitors for various cellular pathways, we demonstrate that SHFV invades cells by low-pH-dependent, actin
Selected aspects related to epidemiology, pathogenesis, immunity, and control of African swine fever
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Woźniakowski Grzegorz
2016-06-01
Full Text Available African swine fever (ASF is currently one of the most severe viral infections of domestic pigs, wild boars, and other hosts belonging to Suidae family. ASF is also considered as the most complex and devastating infectious and haemorrhagic disease of swine due to its severe socio-economic impact and transboundary character. ASF it is a notifiable disease and due to the lack of specific treatment and vaccine, the disease can be only limited by the administrative measures comprising wild boar hunting and stamping out of affected pigs. ASF occurred for the first time in Kenya in 1921 while in Europe (Portugal the virus was detected at the end of the 1950s. In spite of successful eradication of this threat in a number of affected regions, the virus remains endemic in both feral and domestic pigs in Africa and Sardinia. The ‘new era’ of ASF started in 2007 after its re-introduction to Georgia. Following its intensive expansion, the virus spread to other Caucasian countries, including the territory of the Russian Federation. In 2014 the virus reached Ukraine, Belarus, and, consequently, European Union countries: Lithuania, Latvia, Estonia, and Poland. The occurrence of ASF in wild boars and pigs had a severe impact on both epidemiology and economy because of the national and international transport and trade consequences. Up to date, starting from the February 2014, eighty ASF cases in wild boar and three outbreaks in domestic pigs have been diagnosed. Taking into account the diverse rate of spread in Poland, this review aims to present and discuss the current state of knowledge on ASF including its epidemiology, pathology, transmission, and perspectives of control.
Matua, Gerald Amandu; Wal, Dirk Mostert Van der; Locsin, Rozzano C.
2015-01-01
Ebola hemorrhagic fever, caused by the highly virulent RNA virus of the filoviridae family, has become one of the world's most feared pathogens. The virus induces acute fever and death, often associated with hemorrhagic symptoms in up to 90% of infected patients. The known sub-types of the virus are Zaire, Sudan, Taï Forest, Bundibugyo and Reston Ebola viruses. In the past, outbreaks were limited to the East and Central African tropical belt with the exception of Ebola Reston outbreaks that o...
Fernandez, José-Carlos; Billecocq, Agnès; Durand, Jean Paul; Cêtre-Sossah, Catherine; Cardinale, Eric; Marianneau, Philippe; Pépin, Michel; Tordo, Noël; Bouloy, Michèle
2012-01-01
Rift Valley fever (RVF) is an emerging zoonosis in Africa which has spread to Egypt, the Arabian Peninsula, Madagascar, and Comoros. RVF virus (RVFV) (Bunyaviridae family, Phlebovirus genus) causes a wide range of symptoms in humans, from benign fever to fatal hemorrhagic fever. Ruminants are severely affected by the disease, which leads to a high rate of mortality in young animals and to abortions and teratogenesis in pregnant females. Diagnostic tests include virus isolation and genome or antibody detection. During RVFV infection, the nucleoprotein encapsidating the tripartite RNA genome is expressed in large amounts and raises a robust antibody response, while the envelope glycoproteins elicit neutralizing antibodies which play a major role in protection. Much less is known about the antigenicity/immunogenicity of the nonstructural protein NSs, which is a major virulence factor. Here we have developed a competitive enzyme-linked immunosorbent assay (ELISA) enabling detection of low levels of NSs-specific antibodies in naturally infected or vaccinated ruminants. Detection of the NSs antibodies was validated by Western blotting. Altogether, our data showed that the NSs antibodies were detected in only 55% of animals naturally infected by RVFV, indicating that NSs does not induce a consistently high immune response. These results are discussed in light of differentiation between infected and vaccinated animals (DIVA) tests distinguishing naturally infected animals and those vaccinated with NSs-defective vaccines.
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Mary B Crabtree
Full Text Available BACKGROUND: Rift Valley fever virus is an arthropod-borne human and animal pathogen responsible for large outbreaks of acute and febrile illness throughout Africa and the Arabian Peninsula. Reverse genetics technology has been used to develop deletion mutants of the virus that lack the NSs and/or NSm virulence genes and have been shown to be stable, immunogenic and protective against Rift Valley fever virus infection in animals. We assessed the potential for these deletion mutant viruses to infect and be transmitted by Aedes mosquitoes, which are the principal vectors for maintenance of the virus in nature and emergence of virus initiating disease outbreaks, and by Culex mosquitoes which are important amplification vectors. METHODOLOGY AND PRINCIPAL FINDINGS: Aedes aegypti and Culex quinquefasciatus mosquitoes were fed bloodmeals containing the deletion mutant viruses. Two weeks post-exposure mosquitoes were assayed for infection, dissemination, and transmission. In Ae. aegypti, infection and transmission rates of the NSs deletion virus were similar to wild type virus while dissemination rates were significantly reduced. Infection and dissemination rates for the NSm deletion virus were lower compared to wild type. Virus lacking both NSs and NSm failed to infect Ae. aegypti. In Cx. quinquefasciatus, infection rates for viruses lacking NSm or both NSs and NSm were lower than for wild type virus. CONCLUSIONS/SIGNIFICANCE: In both species, deletion of NSm or both NSs and NSm reduced the infection and transmission potential of the virus. Deletion of both NSs and NSm resulted in the highest level of attenuation of virus replication. Deletion of NSm alone was sufficient to nearly abolish infection in Aedes aegypti mosquitoes, indicating an important role for this protein. The double deleted viruses represent an ideal vaccine profile in terms of environmental containment due to lack of ability to efficiently infect and be transmitted by mosquitoes.
Crabtree, Mary B; Kent Crockett, Rebekah J; Bird, Brian H; Nichol, Stuart T; Erickson, Bobbie Rae; Biggerstaff, Brad J; Horiuchi, Kalanthe; Miller, Barry R
2012-01-01
Rift Valley fever virus is an arthropod-borne human and animal pathogen responsible for large outbreaks of acute and febrile illness throughout Africa and the Arabian Peninsula. Reverse genetics technology has been used to develop deletion mutants of the virus that lack the NSs and/or NSm virulence genes and have been shown to be stable, immunogenic and protective against Rift Valley fever virus infection in animals. We assessed the potential for these deletion mutant viruses to infect and be transmitted by Aedes mosquitoes, which are the principal vectors for maintenance of the virus in nature and emergence of virus initiating disease outbreaks, and by Culex mosquitoes which are important amplification vectors. Aedes aegypti and Culex quinquefasciatus mosquitoes were fed bloodmeals containing the deletion mutant viruses. Two weeks post-exposure mosquitoes were assayed for infection, dissemination, and transmission. In Ae. aegypti, infection and transmission rates of the NSs deletion virus were similar to wild type virus while dissemination rates were significantly reduced. Infection and dissemination rates for the NSm deletion virus were lower compared to wild type. Virus lacking both NSs and NSm failed to infect Ae. aegypti. In Cx. quinquefasciatus, infection rates for viruses lacking NSm or both NSs and NSm were lower than for wild type virus. In both species, deletion of NSm or both NSs and NSm reduced the infection and transmission potential of the virus. Deletion of both NSs and NSm resulted in the highest level of attenuation of virus replication. Deletion of NSm alone was sufficient to nearly abolish infection in Aedes aegypti mosquitoes, indicating an important role for this protein. The double deleted viruses represent an ideal vaccine profile in terms of environmental containment due to lack of ability to efficiently infect and be transmitted by mosquitoes.
Prophylactic ethamsylate for periventricular haemorrhage.
Cooke, R W; Morgan, M E
1984-01-01
Drug prophylaxis with ethamsylate for periventricular haemorrhage in very low birthweight infants significantly reduced the incidence of periventricular haemorrhage in survivors. A reduction in abnormalities at follow up and in insertion of ventriculoperitoneal shunts was also noted.
Global emergence of Zika virus
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Richard Tjan
2016-05-01
Full Text Available Zika virus (ZIKV belongs to the flaviviruses (family Flaviviridae, which includes dengue, yellow fever, West Nile, and Japanese encephalitis viruses. Zika virus was isolated in 1947, in the Zika forest near Kampala, Uganda, from one of the rhesus monkeys used as sentinel animals in a yellow fever research program.
Rift Valley fever outbreak--Kenya, November 2006-January 2007.
2007-02-02
In mid-December 2006, several unexplained fatalities associated with fever and generalized bleeding were reported to the Kenya Ministry of Health (KMOH) from Garissa District in North Eastern Province (NEP). By December 20, a total of 11 deaths had been reported. Of serum samples collected from the first 19 patients, Rift Valley fever (RVF) virus RNA or immunoglobulin M (IgM) antibodies against RVF virus were found in samples from 10 patients; all serum specimens were negative for yellow fever, Ebola, Crimean-Congo hemorrhagic fever, and dengue viruses. The outbreak was confirmed by isolation of RVF virus from six of the specimens. Humans can be infected with RVF virus from bites of mosquitoes or other arthropod vectors that have fed on animals infected with RVF virus, or through contact with viremic animals, particularly livestock. Reports of livestock deaths and unexplained animal abortions in NEP provided further evidence of an RVF outbreak. On December 20, an investigation was launched by KMOH, the Kenya Field Epidemiology and Laboratory Training Program (FELTP), the Kenya Medical Research Institute (KEMRI), the Walter Reed Project of the U.S. Army Medical Research Unit, CDC-Kenya's Global Disease Detection Center, and other partners, including the World Health Organization (WHO) and Médecins Sans Frontières (MSF). This report describes the findings from that initial investigation and the control measures taken in response to the RVF outbreak, which spread to multiple additional provinces and districts, resulting in 404 cases with 118 deaths as of January 25, 2007.
Data-driven modeling to assess receptivity for Rift Valley Fever virus.
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Christopher M Barker
2013-11-01
Full Text Available Rift Valley Fever virus (RVFV is an enzootic virus that causes extensive morbidity and mortality in domestic ruminants in Africa, and it has shown the potential to invade other areas such as the Arabian Peninsula. Here, we develop methods for linking mathematical models to real-world data that could be used for continent-scale risk assessment given adequate data on local host and vector populations. We have applied the methods to a well-studied agricultural region of California with [Formula: see text]1 million dairy cattle, abundant and competent mosquito vectors, and a permissive climate that has enabled consistent transmission of West Nile virus and historically other arboviruses. Our results suggest that RVFV outbreaks could occur from February-November, but would progress slowly during winter-early spring or early fall and be limited spatially to areas with early increases in vector abundance. Risk was greatest in summer, when the areas at risk broadened to include most of the dairy farms in the study region, indicating the potential for considerable economic losses if an introduction were to occur. To assess the threat that RVFV poses to North America, including what-if scenarios for introduction and control strategies, models such as this one should be an integral part of the process; however, modeling must be paralleled by efforts to address the numerous remaining gaps in data and knowledge for this system.
Samuel, Glady Hazitha; Wiley, Michael R; Badawi, Atif; Adelman, Zach N; Myles, Kevin M
2016-11-29
Mosquito-borne flaviviruses, including yellow fever virus (YFV), Zika virus (ZIKV), and West Nile virus (WNV), profoundly affect human health. The successful transmission of these viruses to a human host depends on the pathogen's ability to overcome a potentially sterilizing immune response in the vector mosquito. Similar to other invertebrate animals and plants, the mosquito's RNA silencing pathway comprises its primary antiviral defense. Although a diverse range of plant and insect viruses has been found to encode suppressors of RNA silencing, the mechanisms by which flaviviruses antagonize antiviral small RNA pathways in disease vectors are unknown. Here we describe a viral suppressor of RNA silencing (VSR) encoded by the prototype flavivirus, YFV. We show that the YFV capsid (YFC) protein inhibits RNA silencing in the mosquito Aedes aegypti by interfering with Dicer. This VSR activity appears to be broadly conserved in the C proteins of other medically important flaviviruses, including that of ZIKV. These results suggest that a molecular "arms race" between vector and pathogen underlies the continued existence of flaviviruses in nature.
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Paredes J.C.M.
1999-01-01
Full Text Available Serum neutralization tests (SN were performed against classical swine fever virus (CSFV, bovine viral diarrhea virus (BVDV and border disease virus (BDV on samples of swine serum collected for screening of antibodies to CSFV, in order to determine the SN value as a differential serological test. Ninety-nine sera out of a sample of 16,664 were positive for antibodies to pestiviruses in an ELISA test which did not distinguish antibodies to different pestiviruses. When submitted to SN, 81 sera were positive for CSFV antibodies only. In 17 sera, crossreactive antibodies to either CSFV, BVDV or BDV were detected. In most of these sera (13 out of 17 the differences between SN titres against the three viruses were not sufficient to estimate which was the most likely antibody-inducing virus. It was concluded that, for the SN to be useful in such differentiation, it is essential to examine a sample which must include a representative number of sera from the same farm where suspect animals were detected. When isolated serum samples are examined, such as those obtained with the sampling strategy adopted here, the SN may give rise to inconclusive results.
Iroezindu, Michael O; Unigwe, Uche S; Okwara, Celestine C; Ozoh, Gladys A; Ndu, Anne C; Ohanu, Martin E; Nwoko, Ugochukwu O; Okoroafor, Uwadiegwu W; Ejimudo, Esinulo; Tobin, Ekaete A; Asogun, Danny A
2015-11-01
To describe our experiences in the management of a case of Lassa fever (LF) and follow-up of nosocomial primary contacts during the 2014 Ebola outbreak in West Africa. Clinical management of the index case and infection control/surveillance activities for primary contacts are described. Laboratory confirmation was by Lassa virus-specific reverse-transcriptase PCR. A 28-year-old man with a 10-day history of febrile illness was referred to a major tertiary hospital in south-east Nigeria from a city that previously experienced a LF outbreak and was recently affected by Ebola. On observation of haemorrhagic features, clinicians were at a crossroads. Diagnosis of LF was confirmed at a National Reference Centre. The patient died despite initiation of ribavirin therapy. Response activities identified 121 primary contacts comprising 78 (64.5%) hospital staff/interns, 19 (15.7%) medical students, 18 (14.9%) inpatients and 6 (5.0%) relatives. Their mean age was 32.8 ± 6.6 years, and 65.3% were women. Twenty (16.5%) had high-risk exposure and were offered ribavirin as post-exposure prophylaxis. No secondary case of LF occurred. Fatigue (43.8%) and dizziness (31.3%) were the commonest side effects of ribavirin. Response activities contained nosocomial spread of LF, but challenges were experienced including lack of a purpose-built isolation facility, absence of local Lassa virus laboratory capacity, failure to use appropriate protective equipment and stigmatisation of contacts. A key lesson is that the weak health systems of Africa should be comprehensively strengthened; otherwise, we might win the Ebola battle but lose the one against less virulent infections for which effective treatment exists. © 2015 John Wiley & Sons Ltd.
Marco A B Almeida; Jader da C Cardoso; Edmilson Dos Santos; Daltro F da Fonseca; Laura L Cruz; Fernando J C Faraco; Marilina A Bercini; Kátia C Vettorello; Mariana A Porto; Renate Mohrdieck; Tani M S Ranieri; Maria T Schermann; Alethéa F Sperb; Francisco Z Paz; Zenaida M A Nunes
2014-01-01
Author Summary Yellow fever (YF) is a viral hemorrhagic disease that affects humans as well as several species of non-human primates, especially New World monkeys found in South America. Yellow fever virus (YFV) is maintained in a natural cycle involving tree-hole breeding mosquitoes and non-human primates hosts. Because YF is often fatal in susceptible New World monkey populations, sudden die-offs of New World monkeys or epizootics can signal YFV circulation in an environment where humans ma...
Crimean-Congo Hemorrhagic Fever
Directory of Open Access Journals (Sweden)
Emadi Koochak H
2003-10-01
Full Text Available Crimean-Congo hemorrhagic fever (CCHF was first described in the Crimea in 1944 and then in 1956 in congo. CCHF is a viral hemorrhagic fever of the Nairovirus group that belongs to Bunyaviridae family virus. It is transmitted to human by tick bite. The most efficient and common tick that is the vectors of CCHF is a member of the Hyalomma genus which infected many mammals such as livestock, this tick is the main reservoire of virus in nature. Humans also become infected with CCHF virus by direct contact with blood or other infected tissues from livestock or human patients (nosocomial infection. Disease has been found in saharic Africa, Eastern Europe, Pakistan, India and Middle East (specially Iran and Iraq. This disease recently spread in Iran so in 1999 to 2001 at least 222 suspected case(81 definite case reported that led to the death of 15 of 81 cases. It is estimated that 30 percent of the country's cattle are contaminated with this virus."nIn humans, after a short incubation period it appears suddenly with fever, chills, myalgia and GI symptoms followed by severe bleeding and DIC that led to death .If the patient improved, has a long {2-4 weeks convalescence period. Disease diagnosed by clinical manifestations, serologic tests, viral culture and PCR and its specific treatment is oral ribavirin for 10 days, for prevention of disease personal protective measures from tick bite, spraying poison of mews to reduce of ticks crowd, isolation of patients and dis-infection of contaminated personal equipments that who suffering from CCHF is recommended.
Transmission Dinamics Model Of Dengue Fever
Debora; Rendy; Rahmi
2018-01-01
Dengue fever is an endemic disease that is transmitted through the Aedes aegypti mosquito vector. The disease is present in more than 100 countries in America, Africa, and Asia, especially tropical countries. Differential equations can be used to represent the spread of dengue virus occurring in time intervals and model in the form of mathematical models. The mathematical model in this study tries to represent the spread of dengue fever based on the data obtained and the assumptions used. The mathematical model used is a mathematical model consisting of Susceptible (S), Infected (I), Viruses (V) subpopulations. The SIV mathematical model is then analyzed to see the solution behaviour of the system.
Molecular epidemiology of Rabbit Haemorrhagic Disease Virus in Australia: when one became many.
Kovaliski, John; Sinclair, Ron; Mutze, Greg; Peacock, David; Strive, Tanja; Abrantes, Joana; Esteves, Pedro J; Holmes, Edward C
2014-02-01
Rabbit Haemorrhagic Disease Virus (RHDV) was introduced into Australia in 1995 as a biological control agent against the wild European rabbit (Oryctolagus cuniculus). We evaluated its evolution over a 16-year period (1995-2011) by examining 50 isolates collected throughout Australia, as well as the original inoculum strains. Phylogenetic analysis of capsid protein VP60 sequences of the Australian isolates, compared with those sampled globally, revealed that they form a monophyletic group with the inoculum strains (CAPM V-351 and RHDV351INOC). Strikingly, despite more than 3000 rereleases of RHDV351INOC since 1995, only a single viral lineage has sustained its transmission in the long-term, indicative of a major competitive advantage. In addition, we find evidence for widespread viral gene flow, in which multiple lineages entered individual geographic locations, resulting in a marked turnover of viral lineages with time, as well as a continual increase in viral genetic diversity. The rate of RHDV evolution recorded in Australia -4.0 (3.3-4.7) × 10(-3) nucleotide substitutions per site per year - was higher than previously observed in RHDV, and evidence for adaptive evolution was obtained at two VP60 residues. Finally, more intensive study of a single rabbit population (Turretfield) in South Australia provided no evidence for viral persistence between outbreaks, with genetic diversity instead generated by continual strain importation. © 2013 John Wiley & Sons Ltd.
2013-05-10
and pooled (1 to 25 mosquitoes per pool) by species, sex and collection sites using mosquito identification keys by [23-26] and preserved in 1.5 ml...reference and research on arboviruses and haemorrhagic fever viruses. Dakar, Senegal: Institut Pasteur de Dakar; 2000. 8. Kalunda M, Lwanga-Ssozi C
A DNA vaccine against yellow fever virus: development and evaluation.
Directory of Open Access Journals (Sweden)
Milton Maciel
2015-04-01
Full Text Available Attenuated yellow fever (YF virus 17D/17DD vaccines are the only available protection from YF infection, which remains a significant source of morbidity and mortality in the tropical areas of the world. The attenuated YF virus vaccine, which is used worldwide, generates both long-lasting neutralizing antibodies and strong T-cell responses. However, on rare occasions, this vaccine has toxic side effects that can be fatal. This study presents the design of two non-viral DNA-based antigen formulations and the characterization of their expression and immunological properties. The two antigen formulations consist of DNA encoding the full-length envelope protein (p/YFE or the full-length envelope protein fused to the lysosomal-associated membrane protein signal, LAMP-1 (pL/YFE, aimed at diverting antigen processing/presentation through the major histocompatibility complex II precursor compartments. The immune responses triggered by these formulations were evaluated in H2b and H2d backgrounds, corresponding to the C57Bl/6 and BALB/c mice strains, respectively. Both DNA constructs were able to induce very strong T-cell responses of similar magnitude against almost all epitopes that are also generated by the YF 17DD vaccine. The pL/YFE formulation performed best overall. In addition to the T-cell response, it was also able to stimulate high titers of anti-YF neutralizing antibodies comparable to the levels elicited by the 17DD vaccine. More importantly, the pL/YFE vaccine conferred 100% protection against the YF virus in intracerebrally challenged mice. These results indicate that pL/YFE DNA is an excellent vaccine candidate and should be considered for further developmental studies.
A DNA vaccine against yellow fever virus: development and evaluation.
Maciel, Milton; Cruz, Fábia da Silva Pereira; Cordeiro, Marli Tenório; da Motta, Márcia Archer; Cassemiro, Klécia Marília Soares de Melo; Maia, Rita de Cássia Carvalho; de Figueiredo, Regina Célia Bressan Queiroz; Galler, Ricardo; Freire, Marcos da Silva; August, Joseph Thomas; Marques, Ernesto T A; Dhalia, Rafael
2015-04-01
Attenuated yellow fever (YF) virus 17D/17DD vaccines are the only available protection from YF infection, which remains a significant source of morbidity and mortality in the tropical areas of the world. The attenuated YF virus vaccine, which is used worldwide, generates both long-lasting neutralizing antibodies and strong T-cell responses. However, on rare occasions, this vaccine has toxic side effects that can be fatal. This study presents the design of two non-viral DNA-based antigen formulations and the characterization of their expression and immunological properties. The two antigen formulations consist of DNA encoding the full-length envelope protein (p/YFE) or the full-length envelope protein fused to the lysosomal-associated membrane protein signal, LAMP-1 (pL/YFE), aimed at diverting antigen processing/presentation through the major histocompatibility complex II precursor compartments. The immune responses triggered by these formulations were evaluated in H2b and H2d backgrounds, corresponding to the C57Bl/6 and BALB/c mice strains, respectively. Both DNA constructs were able to induce very strong T-cell responses of similar magnitude against almost all epitopes that are also generated by the YF 17DD vaccine. The pL/YFE formulation performed best overall. In addition to the T-cell response, it was also able to stimulate high titers of anti-YF neutralizing antibodies comparable to the levels elicited by the 17DD vaccine. More importantly, the pL/YFE vaccine conferred 100% protection against the YF virus in intracerebrally challenged mice. These results indicate that pL/YFE DNA is an excellent vaccine candidate and should be considered for further developmental studies.
A DNA Vaccine against Yellow Fever Virus: Development and Evaluation
Maciel, Milton; Cruz, Fábia da Silva Pereira; Cordeiro, Marli Tenório; da Motta, Márcia Archer; Cassemiro, Klécia Marília Soares de Melo; Maia, Rita de Cássia Carvalho; de Figueiredo, Regina Célia Bressan Queiroz; Galler, Ricardo; Freire, Marcos da Silva; August, Joseph Thomas; Marques, Ernesto T. A.; Dhalia, Rafael
2015-01-01
Attenuated yellow fever (YF) virus 17D/17DD vaccines are the only available protection from YF infection, which remains a significant source of morbidity and mortality in the tropical areas of the world. The attenuated YF virus vaccine, which is used worldwide, generates both long-lasting neutralizing antibodies and strong T-cell responses. However, on rare occasions, this vaccine has toxic side effects that can be fatal. This study presents the design of two non-viral DNA-based antigen formulations and the characterization of their expression and immunological properties. The two antigen formulations consist of DNA encoding the full-length envelope protein (p/YFE) or the full-length envelope protein fused to the lysosomal-associated membrane protein signal, LAMP-1 (pL/YFE), aimed at diverting antigen processing/presentation through the major histocompatibility complex II precursor compartments. The immune responses triggered by these formulations were evaluated in H2b and H2d backgrounds, corresponding to the C57Bl/6 and BALB/c mice strains, respectively. Both DNA constructs were able to induce very strong T-cell responses of similar magnitude against almost all epitopes that are also generated by the YF 17DD vaccine. The pL/YFE formulation performed best overall. In addition to the T-cell response, it was also able to stimulate high titers of anti-YF neutralizing antibodies comparable to the levels elicited by the 17DD vaccine. More importantly, the pL/YFE vaccine conferred 100% protection against the YF virus in intracerebrally challenged mice. These results indicate that pL/YFE DNA is an excellent vaccine candidate and should be considered for further developmental studies. PMID:25875109
Viral haemorrhagic fevers in South Africa | Richards | South African ...
African Journals Online (AJOL)
As has been demonstrated during the Ebola virus disease outbreak in West Africa, the consequences of VHFs are not limited to specific countries – they may become epidemic, and may have considerable economic impact and disrupt local public health and social service structures. Intensive public health intervention is ...
Burnett, Mark W
2014-01-01
Ebola hemorrhagic fever is an often-fatal disease caused by a virus of the Filoviridae family, genus Ebolavirus. Initial signs and symptoms of the disease are nonspecific, often progressing on to a severe hemorrhagic illness. Special Operations Forces Medical Providers should be aware of this disease, which occurs in sporadic outbreaks throughout Africa. Treatment at the present time is mainly supportive. Special care should be taken to prevent contact with bodily fluids of those infected, which can transmit the virus to caregivers. 2014.
Identification of Wild Boar-Habitat Epidemiologic Cycle in African Swine Fever Epizootic.
Chenais, Erika; Ståhl, Karl; Guberti, Vittorio; Depner, Klaus
2018-04-01
The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar-habitat.
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
Lassa fever or lassa hemorrhagic fever risk to humans from rodent-borne zoonoses.
El-Bahnasawy, Mamdouh M; Megahed, Laila Abdel-Mawla; Abdalla Saleh, Hala Ahmed; Morsy, Tosson A
2015-04-01
Viral hemorrhagic fevers (VHFs) typically manifest as rapidly progressing acute febrile syndromes with profound hemorrhagic manifestations and very high fatality rates. Lassa fever, an acute hemorrhagic fever characterized by fever, muscle aches, sore throat, nausea, vomiting, diarrhea and chest and abdominal pain. Rodents are important reservoirs of rodent-borne zoonosis worldwide. Transmission rodents to humans occur by aerosol spread, either from the genus Mastomys rodents' excreta (multimammate rat) or through the close contact with infected patients (nosocomial infection). Other rodents of the genera Rattus, Mus, Lemniscomys, and Praomys are incriminated rodents hosts. Now one may ask do the rodents' ectoparasites play a role in Lassa virus zoonotic transmission. This paper summarized the update knowledge on LHV; hopping it might be useful to the clinicians, nursing staff, laboratories' personals as well as those concerned zoonoses from rodents and rodent control.
Traumatic primary brain stem haemorrhage
International Nuclear Information System (INIS)
Andrioli, G.C.; Zuccarello, M.; Trincia, G.; Fiore, D.L.; De Caro, R.
1983-01-01
We report 36 cases of post-traumatic 'primary brain stem haemorrhage' visualized by the CT scan and confirmed at autopsy. Clinical experience shows that many technical factors influence the inability to visualize brain stem haemorrhages. Experimental injection of fresh blood into the pons and midbrain of cadavers shows that lesions as small as 0.25 ml in volume may be visualized. The volume and the anatomical configuration of traumatic lesions of the brain stem extended over a rostro-caudal direction, and their proximity to bony structures at the base of the skull are obstacles to the visualization of brain stem haemorrhages. (Author)
A Novel System for Identification of Inhibitors of Rift Valley Fever Virus Replication
Directory of Open Access Journals (Sweden)
Mary E. Piper
2010-03-01
Full Text Available Rift Valley fever virus (RVFV is a human and livestock pathogen endemic to sub-Saharan Africa. We have developed a T7-dependent system for the efficient production of RVFV-like particles (RVF-VLPs based on the virulent ZH-501 strain of RVFV. The RVF-VLPs are capable of performing a single round of infection, allowing for the study of viral replication, assembly, and infectivity. We demonstrate that these RVF-VLPs are antigenically indistinguishable from authentic RVFV and respond similarly to a wide array of known and previously unknown chemical inhibitors. This system should be useful for screening for small molecule inhibitors of RVFV replication.
A novel system for identification of inhibitors of rift valley Fever virus replication.
Piper, Mary E; Gerrard, Sonja R
2010-03-01
Rift Valley fever virus (RVFV) is a human and livestock pathogen endemic to sub-Saharan Africa. We have developed a T7-dependent system for the efficient production of RVFV-like particles (RVF-VLPs) based on the virulent ZH-501 strain of RVFV. The RVF-VLPs are capable of performing a single round of infection, allowing for the study of viral replication, assembly, and infectivity. We demonstrate that these RVF-VLPs are antigenically indistinguishable from authentic RVFV and respond similarly to a wide array of known and previously unknown chemical inhibitors. This system should be useful for screening for small molecule inhibitors of RVFV replication.
Hartman, Amy
2017-06-01
Rift Valley fever (RVF) is a severe veterinary disease of livestock that also causes moderate to severe illness in people. The life cycle of RVF is complex and involves mosquitoes, livestock, people, and the environment. RVF virus is transmitted from either mosquitoes or farm animals to humans, but is generally not transmitted from person to person. People can develop different diseases after infection, including febrile illness, ocular disease, hemorrhagic fever, or encephalitis. There is a significant risk for emergence of RVF into new locations, which would affect human health and livestock industries. Copyright © 2017 Elsevier Inc. All rights reserved.
Neglect and not forgetting produces shameful diseases such as yellow fever
Directory of Open Access Journals (Sweden)
Salim Mattar V
2017-05-01
Full Text Available Yellow fever (YF is a disease caused by a flavivirus that bears its name, is a disease with haemorrhagic manifestations and high lethality that compromises the central nervous system. YF has two cycles; one in the jungle and another urban, epizootics precede outbreaks before migrating to urban areas. The vectors are the mosquitoes Aedes aegypti, Aedes albopictus, Haemogogus janthinomys and Sabethes sp, which have a wide geographical distribution in Colombia and South America.
Panyasing, Yaowalak; Kedkovid, Roongtham; Thanawongnuwech, Roongroje; Kittawornrat, Apisit; Ji, Ju; Giménez-Lirola, Luis; Zimmerman, Jeffrey
2018-03-01
Early recognition and rapid elimination of infected animals is key to controlling incursions of classical swine fever virus (CSFV). In this study, the diagnostic characteristics of 10 CSFV assays were evaluated using individual serum (n = 601) and/or oral fluid (n = 1417) samples collected from -14 to 28 days post inoculation (DPI). Serum samples were assayed by virus isolation (VI), 2 commercial antigen-capture enzyme-linked immunosorbent assays (ELISA), virus neutralization (VN), and 3 antibody ELISAs. Both serum and oral fluid samples were tested with 3 commercial real-time reverse transcription-polymerase chain reaction (rRT-PCR) assays. One or more serum samples was positive by VI from DPIs 3 to 21 and by antigen-capture ELISAs from DPIs 6 to 17. VN-positive serum samples were observed at DPIs ≥ 7 and by antibody ELISAs at DPIs ≥ 10. CSFV RNA was detected in serum samples from DPIs 2 to 28 and in oral fluid samples from DPIs 4 to 28. Significant differences in assay performance were detected, but most importantly, no single combination of sample and assay was able to dependably identify CSFV-inoculated pigs throughout the 4-week course of the study. The results show that effective surveillance for CSFV, especially low virulence strains, will require the use of PCR-based assays for the detection of early infections (<14 days) and antibody-based assays, thereafter. Copyright © 2018 Elsevier B.V. All rights reserved.
Identification of Wild Boar–Habitat Epidemiologic Cycle in African Swine Fever Epizootic
Ståhl, Karl; Guberti, Vittorio; Depner, Klaus
2018-01-01
The African swine fever epizootic in central and eastern European Union member states has a newly identified component involving virus transmission by wild boar and virus survival in the environment. Insights led to an update of the 3 accepted African swine fever transmission models to include a fourth cycle: wild boar–habitat. PMID:29553337
Haemorrhage in intracranial tuber- culosis
African Journals Online (AJOL)
CASE REPORT. 16. SA JOURNAL OF RADIOLOGY • July 2005. Haemorrhage in intracranial tuber- culosis. M Modi. FCRad (SA), MMed. Department of Radiation Sciences ... wall where granulomatous inflamma- tion (Fig. 2, arrow) was present in the adventitia. A specific site of origin for the subarachnoid haemorrhage was.
Concomitant outbreaks of yellow fever and hepatitis E virus in Darfur States, Sudan, 2012.
Ahmed, Sarah S; Soghaier, Mohammed A; Mohammed, Sozan; Khogali, Hayat S; Osman, Muntasir M; Abdalla, Abdalla M
2016-01-31
Yellow fever (YF) is a vector-borne disease transmitted to humans by infected Aedes mosquitoes, while hepatitis E virus (HEV) is a waterborne disease that is transmitted through the fecal-oral route. Both diseases have very close clinical presentation, namely fever, jaundice, malaise, and dark urine; they differ in severity and outcome. In this cross-sectional, laboratory-based study, an attempt was made to measure the correlation of concomitant YF and HEV infection in Darfur States during the previous YF outbreak in 2012. Results found concomitant outbreaks of YF and HEV at the same time with very weak statistical correlation between the two infections during the outbreak period, with Cramer's V correlation 0.05 and insignificant p value of 0.86. This correlation indicates that clinicians and care providers in tropical areas have to deal with clinical case definitions used for disease surveillance very carefully since prevalence of HEV infection is relatively common and this increases the possibility of misclassification and missing YF cases, particularly initial index cases, in a season or outbreak.
Isolation and whole-genome sequencing of a Crimean-Congo hemorrhagic fever virus strain, Greece.
Papa, Anna; Papadopoulou, Elpida; Tsioka, Katerina; Kontana, Anastasia; Pappa, Styliani; Melidou, Ageliki; Giadinis, Nektarios D
2018-03-01
Crimean-Congo hemorrhagic fever virus (CCHFV) was isolated from a pool of two adult Rhipicephalus bursa ticks removed from a goat in 2015 in Greece. The strain clusters into lineage Europe 2 representing the second available whole-genome sequenced isolate of this lineage. CCHFV IgG antibodies were detected in 8 of 19 goats of the farm. Currently CCHFV is not associated with disease in mammals other than humans. Studies in animal models are needed to investigate the pathogenicity level of lineage Europe 2 and compare it with that of other lineages. Copyright © 2018 Elsevier GmbH. All rights reserved.
Filippitzi, M E; Goumperis, T; Robinson, T; Saegerman, C
2017-08-01
As part of the Emerging Risk Identification (ERI) activities of the European Food Safety Authority (EFSA), a literature search was conducted to identify the microbiological agents transmitted between livestock animals and humans that have been suggested as having emerged between 2007 and 2015 in peer-reviewed scientific literature published during the same period (2007-2015). According to the criteria set, the search identified seven such zoonotic agents, namely West Nile Fever virus, Rift Valley Fever virus, Crimean-Congo Haemorrhagic Fever virus, Influenza A H1N1 virus, Coxiella burnetii, Streptococcus suis and livestock-associated methicillin-resistant Staphylococcus aureus clonal complex 398. An explanation of the agents' consideration as emerging risks is provided. The experience gained from these emergences has shown that the detection of and response to such risks can be achieved faster and more successfully within a multidisciplinary, collaborative context at the field, local, national and international levels. © 2016 Blackwell Verlag GmbH.
DEFF Research Database (Denmark)
von Rosen, Tanya; Lohse, Louise; Nielsen, Jens
2013-01-01
Several studies have highlighted the important role of cytokines in disease development of classical swine fever virus (CSFV) infection. In the present study, we examined the kinetics of 7 porcine cytokines in serum from pigs infected with 3 different CSFV strains. Based on the clinical picture i...
Crimean-Congo haemorrhagic fever virus in Kazakhstan (1948-2013
Directory of Open Access Journals (Sweden)
Talgat Nurmakhanov
2015-09-01
The southern regions of Kazakhstan should be considered endemic for CCHF with cases reported from these territories on an annual basis. Modern diagnostic technologies allow for rapid clinical diagnosis and for surveillance studies to monitor for potential expansion in known risk areas.
PROFILE OF HEMATOCRIT LEVEL CAPTURED BY DIGITAL HEMATOCRIT TEST
Widiyanti, Prihartini; Sardjono, Tri Arif
2015-01-01
The dengue fever is a disease caused by Dengue virus which is transmitted via Aedes aegypti and Aedes albopictus vector. This Dengue Haemorrhagic Fever (DHF) case in Indonesia tend to rise from year to year caused by delayed detection and inadequate handling. The laboratory parameter of hematocrite had regularly been performed using invasive method by taking the blood from the patient. This method is still not been able to monitor patients with DHF by repetitive and accurate measurament. This...
Puumala hantavirus infections in bank vole populations: host and virus dynamics in Central Europe.
Reil, Daniela; Rosenfeld, Ulrike M; Imholt, Christian; Schmidt, Sabrina; Ulrich, Rainer G; Eccard, Jana A; Jacob, Jens
2017-02-28
In Europe, bank voles (Myodes glareolus) are widely distributed and can transmit Puumala virus (PUUV) to humans, which causes a mild to moderate form of haemorrhagic fever with renal syndrome, called nephropathia epidemica. Uncovering the link between host and virus dynamics can help to prevent human PUUV infections in the future. Bank voles were live trapped three times a year in 2010-2013 in three woodland plots in each of four regions in Germany. Bank vole population density was estimated and blood samples collected to detect PUUV specific antibodies. We demonstrated that fluctuation of PUUV seroprevalence is dependent not only on multi-annual but also on seasonal dynamics of rodent host abundance. Moreover, PUUV infection might affect host fitness, because seropositive individuals survived better from spring to summer than uninfected bank voles. Individual space use was independent of PUUV infections. Our study provides robust estimations of relevant patterns and processes of the dynamics of PUUV and its rodent host in Central Europe, which are highly important for the future development of predictive models for human hantavirus infection risk.
Virus isolation for diagnosing dengue virus infections in returning travelers
Teichmann, D.; Göbels, K.; Niedrig, M.; Sim-Brandenburg, J.-W.; Làge-Stehr, J.; Grobusch, M. P.
2003-01-01
Dengue fever is recognized as one of the most frequent imported acute febrile illnesses affecting European tourists returning from the tropics. In order to assess the value of virus isolation for the diagnosis of dengue fever, 70 cases of dengue fever confirmed in German travelers during the period
Grau, Frederic R; Schroeder, Megan E; Mulhern, Erin L; McIntosh, Michael T; Bounpheng, Mangkey A
2015-03-01
African swine fever (ASF), classical swine fever (CSF), and foot-and-mouth disease (FMD) are highly contagious animal diseases of significant economic importance. Pigs infected with ASF and CSF viruses (ASFV and CSFV) develop clinical signs that may be indistinguishable from other diseases. Likewise, various causes of vesicular disease can mimic clinical signs caused by the FMD virus (FMDV). Early detection is critical to limiting the impact and spread of these disease outbreaks, and the ability to perform herd-level surveillance for all 3 diseases rapidly and cost effectively using a single diagnostic sample and test is highly desirable. This study assessed the feasibility of simultaneous ASFV, CSFV, and FMDV detection by multiplex reverse transcription real-time polymerase chain reaction (mRT-qPCR) in swine oral fluids collected through the use of chewing ropes. Animal groups were experimentally infected independently with each virus, observed for clinical signs, and oral fluids collected and tested throughout the course of infection. All animal groups chewed on the ropes readily before and after onset of clinical signs and before onset of lameness or serious clinical signs. ASFV was detected as early as 3 days postinoculation (dpi), 2-3 days before onset of clinical disease; CSFV was detected at 5 dpi, coincident with onset of clinical disease; and FMDV was detected as early as 1 dpi, 1 day before the onset of clinical disease. Equivalent results were observed in 4 independent studies and demonstrate the feasibility of oral fluids and mRT-qPCR for surveillance of ASF, CSF, and FMD in swine populations. © 2015 The Author(s).
Sherifi, Kurtesh; Rexhepi, Agim; Berxholi, Kristaq; Mehmedi, Blerta; Gecaj, Rreze M.; Hoxha, Zamira; Joachim, Anja; Duscher, Georg G.
2018-01-01
Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218), Dermacentor marginatus (n = 98), and Haemaphysalis spp. (n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma marginatum (n = 199 from Kosovo, all from Kosovo) and Rhipicephalus bursa (n = 130, 126 from Albania) could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean–Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle) from the Prishtina region (Kosovo). B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus, two I. ricinus one female and one male) from the Mitrovica region (Kosovo). Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus, but also in D. marginatus, in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established. PMID:29560357
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Kurtesh Sherifi
2018-03-01
Full Text Available Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean–Congo hemorrhagic fever (CCHF is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE. Therefore, we sampled and tested 795 ticks. Ixodes ricinus (n = 218, Dermacentor marginatus (n = 98, and Haemaphysalis spp. (n = 24 were collected from the environment by flagging (all from Kosovo, while Hyalomma marginatum (n = 199 from Kosovo, all from Kosovo and Rhipicephalus bursa (n = 130, 126 from Albania could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean–Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle from the Prishtina region (Kosovo. B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus, two I. ricinus one female and one male from the Mitrovica region (Kosovo. Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus, but also in D. marginatus, in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established.
Sherifi, Kurtesh; Rexhepi, Agim; Berxholi, Kristaq; Mehmedi, Blerta; Gecaj, Rreze M; Hoxha, Zamira; Joachim, Anja; Duscher, Georg G
2018-01-01
Tick-borne diseases pose a serious threat to human health in South-Eastern Europe, including Kosovo. While Crimean-Congo hemorrhagic fever (CCHF) is a well-known emerging infection in this area, there are no accurate data on Lyme borreliosis and tick-borne encephalitis (TBE). Therefore, we sampled and tested 795 ticks. Ixodes ricinus ( n = 218), Dermacentor marginatus ( n = 98), and Haemaphysalis spp. ( n = 24) were collected from the environment by flagging (all from Kosovo), while Hyalomma marginatum ( n = 199 from Kosovo, all from Kosovo) and Rhipicephalus bursa ( n = 130, 126 from Albania) could be collected only by removal from animal pasture and domestic ruminants. Ticks were collected in the years 2014/2015 and tested for viral RNA of CCHF and TBE viruses, as well as for DNA of Borrelia burgdorferi sensu lato by real-time PCR. In Kosovo, nine ticks were positive for RNA of Crimean-Congo hemorrhagic fever virus and seven for DNA of B. burgdorferi s. l. None of the ticks tested positive for TBEV. CCHF virus was detected in one H. marginatum male specimen collected while feeding on grazing cattle from the Prizren region and in eight R. bursa specimens (five females and three males collected while feeding on grazing sheep and cattle) from the Prishtina region (Kosovo). B. burgdorferi s. l. was detected in seven questing ticks (four male and one female D. marginatus , two I. ricinus one female and one male) from the Mitrovica region (Kosovo). Our study confirmed that CCHF virus is circulating in Kosovo mainly in H. marginatum and R. bursa in the central areas of the country. B. burgdorferi s. l. was found in its major European host tick, I. ricinus , but also in D. marginatus , in the north of the Kosovo. In order to prevent the spread of these diseases and better control of the tick-borne infections, an improved vector surveillance and testing of ticks for the presence of pathogens needs to be established.
T cell Receptor Alpha Variable 12-2 bias in the immunodominant response to Yellow fever virus
Bovay, Amandine; Zoete, Vincent; Dolton, Garry; Bulek, Anna M.; Cole, David K.; Rizkallah, Pierre J.; Fuller, Anna; Beck, Konrad; Michielin, Olivier; Speiser, Daniel E.; Sewell, Andrew K.; Fuertes Marraco, Silvia A.
2018-01-01
The repertoire of human αβ T-cell receptors (TCRs) is generated via somatic recombination of germline gene segments. Despite this enormous variation, certain epitopes can be immunodominant, associated with high frequencies of antigen-specific T cells and/or exhibit bias toward a TCR gene segment. Here, we studied the TCR repertoire of the HLA-A*0201-restricted epitope LLWNGPMAV (hereafter, A2/LLW) from Yellow Fever virus, which generates an immunodominant CD8 javax.xml.bind.JAXBElement@714aac...
The early use of yellow fever virus strain 17D for vaccine production in Brazil - a review
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Paulo Roberto Post
2001-08-01
Full Text Available The use of yellow fever (YF virus 17D strain for vaccine production adapted in Brazil since its introduction in 1937 was reviewed. This was possible due to the availability of official records of vaccine production. The retrieved data highlight the simultaneous use of several serially passaged 17D substrain viruses for both inocula and vaccine preparation that allowed uninterrupted production. Substitution of these substrain viruses became possible with the experience gained during quality control and human vaccination. Post-vaccinal complications in humans and the failure of some viruses in quality control tests (neurovirulence for monkeys indicated that variables needed to be reduced during vaccine production, leading to the development of the seed lot system. The 17DD substrain, still used today, was the most frequently used substrain and the most reliable in terms of safety and efficacy. For this reason, it is possible to derive an infectious cDNA clone of this substrain combined with production in cell culture that could be used to direct the expression of heterologous antigens and lead to the development of new live vaccines.
Hakobyan, Astghik; Galindo, Inmaculada; Nañez, Almudena; Arabyan, Erik; Karalyan, Zaven; Chistov, Alexey A; Streshnev, Philipp P; Korshun, Vladimir A; Alonso, Covadonga; Zakaryan, Hovakim
2018-01-01
Rigid amphipathic fusion inhibitors (RAFIs) are a family of nucleoside derivatives that inhibit the infectivity of several enveloped viruses by interacting with virion envelope lipids and inhibiting fusion between viral and cellular membranes. Here we tested the antiviral activity of two RAFIs, 5-(Perylen-3-ylethynyl)-arabino-uridine (aUY11) and 5-(Perylen-3-ylethynyl)uracil-1-acetic acid (cm1UY11) against African swine fever virus (ASFV), for which no effective vaccine is available. Both compounds displayed a potent, dose-dependent inhibitory effect on ASFV infection in Vero cells. The major antiviral effect was observed when aUY11 and cm1UY11 were added at early stages of infection and maintained during the complete viral cycle. Furthermore, virucidal assay revealed a significant extracellular anti-ASFV activity for both compounds. We also found decrease in the synthesis of early and late viral proteins in Vero cells treated with cm1UY11. Finally, the inhibitory effect of aUY11 and cm1UY11 on ASFV infection in porcine alveolar macrophages was confirmed. Overall, our study has identified novel anti-ASFV compounds with potential for future therapeutic developments.
Analysis of classical swine fever virus RNA replication determinants using replicons
DEFF Research Database (Denmark)
Risager, Peter Christian; Fahnøe, Ulrik; Gullberg, Maria
2013-01-01
Self-replicating RNAs (replicons), with or without reporter gene sequences, derived from the genome of the Paderborn strain of classical swine fever virus (CSFV) have been produced. The full-length viral cDNA, propagated within a bacterial artificial chromosome (BAC), was modified by targeted...... recombination within E. coli. RNA transcripts were produced in vitro and introduced into cells by electroporation. The translation and replication of the replicon RNAs could be followed by the accumulation of luciferase (from Renilla reniformis or Gaussia princeps) protein expression (where appropriate......), as well as by detection of the CSFV NS3 protein production within the cells. Inclusion of the viral E2 coding region within the replicon was advantageous for the replication efficiency. Production of chimeric RNAs, substituting the NS2 and NS3 coding regions (as a unit) from the Paderborn strain...
Molecular detection of Crimean-Congo hemorrhagic fever virus in ticks, Greece, 2012-2014.
Papa, Anna; Kontana, Anastasia; Tsioka, Katerina; Chaligiannis, Ilias; Sotiraki, Smaragda
2017-11-01
Crimean-Congo hemorrhagic fever virus (CCHFV) is transmitted to humans mainly through the bite of infected ticks. In Greece, only one clinical case has been observed, in 2008, but the seroprevalence in humans is relatively high (4.2%). To have a first insight into the circulation of CCHFV in Greece, 2000 ticks collected from livestock during 2012-2014 were tested. CCHFV was detected in 36 of the 1290 (2.8%) tick pools (1-5 ticks per pool). Two genetic lineages were identified: Europe 1 and Europe 2. Most Europe 1 sequences were obtained from Rhipicephalus sanguineus sensu lato ticks, while most Europe 2 sequences were recovered from Rhipicephalus bursa ticks. The number of collected Hyalomma marginatum ticks (the principal vector of CCHFV) was low (0.5% of ticks) and all were CCHFV negative. Since it is not known how efficient ticks of the Rhipicephalus genus are as vectors of the virus, laboratory studies will be required to explore the role of Rhipicephalus spp. ticks in CCHFV maintenance and transmission.
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Cigdem Alkan
2016-03-01
Full Text Available Many studies have presented virus sequences which suggest the existence of a variety of putative new phleboviruses transmitted by sandflies in the Old World. However, in most of these studies, only partial sequences in the polymerase or the nucleoprotein genes were characterised. Therefore to further our understand of the presence and potential medical importance of sandfly-borne phleboviruses that circulate in southern Anatolia, we initiated field campaigns in 2012 and 2013 designed to identify, isolate and characterise phleboviruses in sandflies in this region.An entomological investigation encompassing 8 villages in Adana, Mediterranean Turkey was performed in August and September 2012 and 2013. A total of 11,302 sandflies were collected and grouped into 797 pools which were tested for the presence of phleboviruses using specific primers for RT-PCR analysis and also cell culture methods for virus isolation. Seven pools were PCR positive, and viruses were isolated from three pools of sandflies, resulting in the identification of two new viruses that we named Zerdali virus and Toros virus. Phylogenetic analysis based on full-length genomic sequence showed that Zerdali virus was most closely related with Tehran virus (and belongs to the Sandfly fever Naples species, whereas Toros virus was closest to Corfou virus.The results indicate that a variety of phleboviruses are co-circulating in this region of southern Anatolia. Based on our studies, these new viruses clearly belong to genetic groups that include several human pathogens. However, whether or not Toros and Zerdali viruses can infect humans and cause diseases such as sandfly fever remains to be investigated.
Review of Lassa fever, an emerging old world haemorrhagic viral ...
African Journals Online (AJOL)
... Laboratory/diagnostic and care centres), poor socioeconomic environment, lack of ... of the natural host and reservoir mouse (Mastomys natalensis) of Lassa virus . ... The stakeholders need to prioritize intervention and support program and ...
Carlson, Jolene; O'Donnell, Vivian; Alfano, Marialexia; Velazquez Salinas, Lauro; Holinka, Lauren G; Krug, Peter W; Gladue, Douglas P; Higgs, Stephen; Borca, Manuel V
2016-10-22
African swine fever (ASF) is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV). There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4) virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus) is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi) showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi). This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN)-γ responses, or specific cytokine profiles) and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms.
Chastel, C
1999-01-01
A few million years ago, when primates moved from the east African forest to the savannah, they were already infected with endogenous viruses and occultly transmitted them to the prime Homo species. However it was much later with the building of the first large cities in Mesopotamia that interhuman viral transmission began in earnest. Spreading was further enhanced with the organization of the Egyptian, Greek, Roman, and Arab empires around the Mediterranean. Discovery of the New World in 1492 led to an unprecedented clash of civilizations and the destruction of pre-Columbian Indian civilizations. It also led to a rapid spread of viruses across the Atlantic Ocean with the emergence of yellow fever and appearance of smallpox and measles throughout the world. However the greatest opportunities for worldwide viral development have been created by our present, modern civilization. This fact is illustrated by epidemic outbreaks of human immunodeficiency virus, Venezuela hemorrhagic fever, Rift valley fever virus, and monkey pox virus. Close analysis underscores the major role of human intervention in producing these events.
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Sônia Regina Nogueira Ignácio Reis
2007-12-01
Full Text Available An important cytokine role in dengue fever pathogenesis has been described. These molecules can be associated with haemorrhagic manifestations, coagulation disorders, hypotension and shock, all symptoms implicated in vascular permeability and disease worsening conditions. Several immunological diseases have been treated by cytokine modulation and dexamethasone is utilized clinically to treat pathologies with inflammatory and autoimmune ethiologies. We established an in vitro model with human monocytes infected by dengue virus-2 for evaluating immunomodulatory and antiviral activities of potential pharmaceutical products. Flow cytometry analysis demonstrated significant dengue antigen detection in target cells two days after infection. TNF-alpha, IFN-alpha, IL-6 and IL-10 are produced by in vitro infected monocytes and are significantly detected in cell culture supernatants by multiplex microbead immunoassay. Dexamethasone action was tested for the first time for its modulation in dengue infection, presenting optimistic results in both decreasing cell infection rates and inhibiting TNF-alpha, IFN-alpha and IL-10 production. This model is proposed for novel drug trials yet to be applyed for dengue fever.
DNA Vaccine Electroporation and Molecular Adjuvants
2016-03-16
Suschak and Schmaljohn DNA Vaccine Electroporation and Molecular Adjuvants 1 Abstract To date, there is no protective vaccine for Ebola virus...the formulation of DNA launched virus-like particles (VLP). In this case, the antigen is encoded in one DNA plasmid, while structural proteins are...Virol, 2010. 155(12): p. 2083-103. 2. Feldmann, H. and T.W. Geisbert, Ebola haemorrhagic fever. Lancet, 2011. 377(9768): p. 849-62. 3. Hart, M.K
Magnetic resonance imaging of central nervous system haemorrhage
International Nuclear Information System (INIS)
Silberstein, M.; Hennessy, O.
1993-01-01
The variable magnetic resonance imaging appearances of central nervous system haemorrhage, both intra- and extra-axial, are described. These will vary with the type of image contrast (T1 or T2 weighting), the nature of the imaging sequence (spin-echo or gradient-echo) and the time from onset of haemorrhage. Magnetic resonance imaging is a useful technique for imaging haemorrhage in the central nervous system as it yields temporal information about haematoma development, and it is the only non-invasive means of imaging intraspinal haemorrhage. However, in the imaging of haematomas within 24 h of onset and in subarachnoid haemorrhage computed tomography is the investigation of choice. 13 refs., 6 figs
Kovaliski, John; Sinclair, Ron; Mutze, Greg; Peacock, David; Strive, Tanja; Abrantes, Joana; Esteves, Pedro J.; Holmes, Edward C.
2015-01-01
Rabbit Haemorrhagic Disease Virus (RHDV) was introduced into Australia in 1995 as a biological control agent against the wild European rabbit (Oryctolagus cuniculus). We evaluated its evolution over a 16 year period (1995–2011) by examining 50 isolates collected throughout Australia, as well as the original inoculum strains. Phylogenetic analysis of capsid protein VP60 sequences of the Australian isolates, compared to those sampled globally, revealed that they form a monophyletic group with the inoculum strains (CAPM V-351 and RHDV351INOC). Strikingly, despite more than 3000 re-releases of RHDV351INOC since 1995, only a single viral lineage has sustained its transmission in the long-term, indicative of a major competitive advantage. In addition, we find evidence for widespread viral gene flow, in which multiple lineages entered individual geographic locations, resulting in a marked turnover of viral lineages with time, as well as a continual increase in viral genetic diversity. The rate of RHDV evolution recorded in Australia – 4.0 (3.3 – 4.7) × 10−3 nucleotide substitutions per site per year – was higher than previously observed in RHDV, and evidence for adaptive evolution was obtained at two VP60 residues. Finally, more intensive study of a single rabbit population (Turretfield) in South Australia provided no evidence for viral persistence between outbreaks, with genetic diversity instead generated by continual strain importation. PMID:24251353
Velazquez-Salinas, Lauro; Risatti, Guillermo R; Holinka, Lauren G; O'Donnell, Vivian; Carlson, Jolene; Alfano, Marialexia; Rodriguez, Luis L; Carrillo, Consuelo; Gladue, Douglas P; Borca, Manuel V
2016-07-01
Controlling classical swine fever (CSF) mainly involves vaccination with live attenuated vaccines (LAV). Experimental CSFV LAVs has been lately developed through reverse genetics using several different approaches. Here we present that codon de-optimization in the major CSFV structural glycoprotein E2 coding region, causes virus attenuation in swine. Four different mutated constructs (pCSFm1-pCSFm4) were designed using various mutational approaches based on the genetic background of the highly virulent strain Brescia (BICv). Three of these constructs produced infectious viruses (CSFm2v, CSFm3v, and CSFm4v). Animals infected with CSFm2v presented a reduced and extended viremia but did not display any CSF-related clinical signs. Animals that were infected with CSFm2v were protected against challenge with virulent parental BICv. This is the first report describing the development of an attenuated CSFV experimental vaccine by codon usage de-optimization, and one of the few examples of virus attenuation using this methodology that is assessed in a natural host. Published by Elsevier Inc.
Ellenbecker, Mary; Lanchy, Jean-Marc; Lodmell, J. Stephen
2012-01-01
Rift Valley fever virus (RVFV) is an emerging infectious pathogen that causes severe disease in humans and livestock and has the potential for global spread. Currently, there is no proven effective treatment for RVFV infection and there is no licensed vaccine. Inhibition of RNA binding to the essential viral nucleocapsid (N) protein represents a potential anti-viral therapeutic strategy because all of the functions performed by N during infection involve RNA binding. To target this interactio...
Lundu, Tapiwa; Yoshii, Kentaro; Kobayashi, Shintaro; Morikawa, Shigeru; Tsubota, Toshio; Misawa, Naoaki; Hayasaka, Daisuke; Kariwa, Hiroaki
2018-01-01
Severe fever with thrombocytopenia syndrome (SFTS) is a newly recognized zoonosis that occurs in China, Japan, and South Korea and is caused by the SFTS virus (SFTSV), which is in the genus Phlebovirus, family Phenuiviridae. Since its discovery in Japan in 2013, SFTS has been reported in the western parts of the country. To elucidate the distribution of SFTSV, we conducted a serological survey of deer and rodents. Serum was screened using enzyme-linked immunosorbent assay (ELISA) and suspecte...
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Florine E.M. Scholte
2017-09-01
Full Text Available Antiviral responses are regulated by conjugation of ubiquitin (Ub and interferon-stimulated gene 15 (ISG15 to proteins. Certain classes of viruses encode Ub- or ISG15-specific proteases belonging to the ovarian tumor (OTU superfamily. Their activity is thought to suppress cellular immune responses, but studies demonstrating the function of viral OTU proteases during infection are lacking. Crimean-Congo hemorrhagic fever virus (CCHFV, family Nairoviridae is a highly pathogenic human virus that encodes an OTU with both deubiquitinase and deISGylase activity as part of the viral RNA polymerase. We investigated CCHFV OTU function by inactivating protease catalytic activity or by selectively disrupting its deubiquitinase and deISGylase activity using reverse genetics. CCHFV OTU inactivation blocked viral replication independently of its RNA polymerase activity, while deubiquitinase activity proved critical for suppressing the interferon responses. Our findings provide insights into viral OTU functions and support the development of therapeutics and vaccines.
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.
Bray, Mike; Geisbert, Thomas W
2005-08-01
Ebola hemorrhagic fever is a severe viral infection characterized by fever, shock and coagulation defects. Recent studies in macaques show that major features of illness are caused by effects of viral replication on macrophages and dendritic cells. Infected macrophages produce proinflammatory cytokines, chemokines and tissue factor, attracting additional target cells and inducing vasodilatation, increased vascular permeability and disseminated intravascular coagulation. However, they cannot restrict viral replication, possibly because of suppression of interferon responses. Infected dendritic cells also secrete proinflammatory mediators, but cannot initiate antigen-specific responses. In consequence, virus disseminates to these and other cell types throughout the body, causing multifocal necrosis and a syndrome resembling septic shock. Massive "bystander" apoptosis of natural killer and T cells further impairs immunity. These findings suggest that modifying host responses would be an effective therapeutic strategy, and treatment of infected macaques with a tissue-factor inhibitor reduced both inflammation and viral replication and improved survival.
Estimation of the transmission dynamics of African swine fever virus within a swine house
DEFF Research Database (Denmark)
Nielsen, J. P.; Larsen, T. S.; Hisham Beshara Halasa, Tariq
2017-01-01
The spread of African swine fever virus (ASFV) threatens to reach further parts of Europe. In countries with a large swine production, an outbreak of ASF may result in devastating economic consequences for the swine industry. Simulation models can assist decision makers setting up contingency plans......·00 (95% CI 0-1). Furthermore, we simulated the spread of ASFV within a pig house using a modified SEIR-model to establish the time from infection of one animal until ASFV is detected in the herd. Based on a chosen detection limit of 2·55% equivalent to 10 dead pigs out of 360, the disease would...
Rift Valley fever virus seroprevalence in human rural populations of Gabon.
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Xavier Pourrut
Full Text Available BACKGROUND: Rift Valley fever (RVF is a mosquito-borne viral zoonosis caused by a phlebovirus and transmitted by Aedes mosquitoes. Humans can also be infected through direct contact with blood (aerosols or tissues (placenta, stillborn of infected animals. Although severe clinical cases can be observed, infection with RVF virus (RVFV in humans is, in most cases, asymptomatic or causes a febrile illness without serious symptoms. In small ruminants RVFV mainly causes abortion and neonatal death. The distribution of RVFV has been well documented in many African countries, particularly in the north (Egypt, Sudan, east (Kenya, Tanzania, Somalia, west (Senegal, Mauritania and south (South Africa, but also in the Indian Ocean (Madagascar, Mayotte and the Arabian Peninsula. In contrast, the prevalence of RVFV has rarely been investigated in central African countries. METHODOLOGY/PRINCIPAL FINDINGS: We therefore conducted a large serological survey of rural populations in Gabon, involving 4,323 individuals from 212 randomly selected villages (10.3% of all Gabonese villages. RVFV-specific IgG was found in a total of 145 individuals (3.3% suggesting the wide circulation of Rift Valley fever virus in Gabon. The seroprevalence was significantly higher in the lakes region than in forest and savannas zones, with respective rates of 8.3%, 2.9% and 2.2%. In the lakes region, RVFV-specific IgG was significantly more prevalent in males than in females (respectively 12.8% and 3.8% and the seroprevalence increased gradually with age in males but not in females. CONCLUSIONS/SIGNIFICANCE: Although RVFV was suggested to circulate at a relatively high level in Gabon, no outbreaks or even isolated cases have been documented in the country. The higher prevalence in the lakes region is likely to be driven by specific ecologic conditions favorable to certain mosquito vector species. Males may be more at risk of infection than females because they spend more time farming and
A review of zoonotic disease surveillance supported by the Armed Forces Health Surveillance Center.
Burke, R L; Kronmann, K C; Daniels, C C; Meyers, M; Byarugaba, D K; Dueger, E; Klein, T A; Evans, B P; Vest, K G
2012-05-01
The Armed Forces Health Surveillance Center (AFHSC), Division of Global Emerging Infections Surveillance and Response System conducts disease surveillance through a global network of US Department of Defense research laboratories and partnerships with foreign ministries of agriculture, health and livestock development in over 90 countries worldwide. In 2010, AFHSC supported zoonosis survey efforts were organized into four main categories: (i) development of field assays for animal disease surveillance during deployments and in resource limited environments, (ii) determining zoonotic disease prevalence in high-contact species which may serve as important reservoirs of diseases and sources of transmission, (iii) surveillance in high-risk human populations which are more likely to become exposed and subsequently infected with zoonotic pathogens and (iv) surveillance at the human-animal interface examining zoonotic disease prevalence and transmission within and between human and animal populations. These efforts have aided in the detection, identification and quantification of the burden of zoonotic diseases such as anthrax, brucellosis, Crimean Congo haemorrhagic fever, dengue fever, Hantaan virus, influenza, Lassa fever, leptospirosis, melioidosis, Q fever, Rift Valley fever, sandfly fever Sicilian virus, sandfly fever Naples virus, tuberculosis and West Nile virus, which are of military and public health importance. Future zoonotic surveillance efforts will seek to develop local capacity for zoonotic surveillance focusing on high risk populations at the human-animal interface. © 2011 Blackwell Verlag GmbH.
Advanced Vaccine Candidates for Lassa Fever
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Igor S. Lukashevich
2012-10-01
Full Text Available Lassa virus (LASV is the most prominent human pathogen of the Arenaviridae. The virus is transmitted to humans by a rodent reservoir, Mastomys natalensis, and is capable of causing lethal Lassa Fever (LF. LASV has the highest human impact of any of the viral hemorrhagic fevers (with the exception of Dengue Fever with an estimated several hundred thousand infections annually, resulting in thousands of deaths in Western Africa. The sizeable disease burden, numerous imported cases of LF in non-endemic countries, and the possibility that LASV can be used as an agent of biological warfare make a strong case for vaccine development. Presently there is no licensed vaccine against LF or approved treatment. Recently, several promising vaccine candidates have been developed which can potentially target different groups at risk. The purpose of this manuscript is to review the LASV pathogenesis and immune mechanisms involved in protection. The current status of pre-clinical development of the advanced vaccine candidates that have been tested in non-human primates will be discussed. Major scientific, manufacturing, and regulatory challenges will also be considered.
Bárcena, Juan; Guerra, Beatriz; Angulo, Iván; González, Julia; Valcárcel, Félix; Mata, Carlos P; Castón, José R; Blanco, Esther; Alejo, Alí
2015-09-24
In 2010 a new Lagovirus related to rabbit haemorrhagic disease virus (RHDV) emerged in France and has since rapidly spread throughout domestic and wild rabbit populations of several European countries. The new virus, termed RHDV2, exhibits distinctive genetic, antigenic and pathogenic features. Notably, RHDV2 kills rabbits previously vaccinated with RHDV vaccines. Here we report for the first time the generation and characterization of RHDV2-specific virus-like particles (VLPs). Our results further confirmed the differential antigenic properties exhibited by RHDV and RHDV2, highlighting the need of using RHDV2-specific diagnostic assays to monitor the spread of this new virus.
International Nuclear Information System (INIS)
Chotiyarnwong, Pojchong; Stewart-Jones, Guillaume B.; Tarry, Michael J.; Dejnirattisai, Wanwisa; Siebold, Christian; Koch, Michael; Stuart, David I.; Harlos, Karl; Malasit, Prida; Screaton, Gavin; Mongkolsapaya, Juthathip; Jones, E. Yvonne
2007-01-01
Crystals of an MHC class I molecule bound to naturally occurring peptide variants from the dengue virus NS3 protein contained high levels of solvent and required optimization of cryoprotectant and dehydration protocols for each complex to yield well ordered diffraction, a process facilitated by the use of a free-mounting system. T-cell recognition of the antigenic peptides presented by MHC class I molecules normally triggers protective immune responses, but can result in immune enhancement of disease. Cross-reactive T-cell responses may underlie immunopathology in dengue haemorrhagic fever. To analyze these effects at the molecular level, the functional MHC class I molecule HLA-A*1101 was crystallized bound to six naturally occurring peptide variants from the dengue virus NS3 protein. The crystals contained high levels of solvent and required optimization of the cryoprotectant and dehydration protocols for each complex to yield well ordered diffraction, a process that was facilitated by the use of a free-mounting system
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Chotiyarnwong, Pojchong [Department of Immunology, Division of Medicine, Hammersmith Hospital, Imperial College, London (United Kingdom); Medical Molecular Biology Unit, Faculty of Medicine, Siriraj Hospital, Mahidol University (Thailand); Stewart-Jones, Guillaume B.; Tarry, Michael J. [Division of Structural Biology and Oxford Protein Production Facility (OPPF), The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Headington, Oxford OX3 7BN (United Kingdom); Dejnirattisai, Wanwisa [Department of Immunology, Division of Medicine, Hammersmith Hospital, Imperial College, London (United Kingdom); Medical Molecular Biology Unit, Faculty of Medicine, Siriraj Hospital, Mahidol University (Thailand); Siebold, Christian; Koch, Michael; Stuart, David I.; Harlos, Karl [Division of Structural Biology and Oxford Protein Production Facility (OPPF), The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Headington, Oxford OX3 7BN (United Kingdom); Malasit, Prida [Medical Molecular Biology Unit, Faculty of Medicine, Siriraj Hospital, Mahidol University (Thailand); Medical Biotechnology Unit, National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, Pathumthani, Bangkok (Thailand); Screaton, Gavin [Department of Immunology, Division of Medicine, Hammersmith Hospital, Imperial College, London (United Kingdom); Mongkolsapaya, Juthathip, E-mail: j.mongkolsapaya@imperial.ac.uk [Department of Immunology, Division of Medicine, Hammersmith Hospital, Imperial College, London (United Kingdom); Medical Molecular Biology Unit, Faculty of Medicine, Siriraj Hospital, Mahidol University (Thailand); Jones, E. Yvonne, E-mail: j.mongkolsapaya@imperial.ac.uk [Division of Structural Biology and Oxford Protein Production Facility (OPPF), The Henry Wellcome Building for Genomic Medicine, Roosevelt Drive, Headington, Oxford OX3 7BN (United Kingdom); Department of Immunology, Division of Medicine, Hammersmith Hospital, Imperial College, London (United Kingdom)
2007-05-01
Crystals of an MHC class I molecule bound to naturally occurring peptide variants from the dengue virus NS3 protein contained high levels of solvent and required optimization of cryoprotectant and dehydration protocols for each complex to yield well ordered diffraction, a process facilitated by the use of a free-mounting system. T-cell recognition of the antigenic peptides presented by MHC class I molecules normally triggers protective immune responses, but can result in immune enhancement of disease. Cross-reactive T-cell responses may underlie immunopathology in dengue haemorrhagic fever. To analyze these effects at the molecular level, the functional MHC class I molecule HLA-A*1101 was crystallized bound to six naturally occurring peptide variants from the dengue virus NS3 protein. The crystals contained high levels of solvent and required optimization of the cryoprotectant and dehydration protocols for each complex to yield well ordered diffraction, a process that was facilitated by the use of a free-mounting system.
Directory of Open Access Journals (Sweden)
Adriana Ribeiro Carneiro
2012-09-01
Full Text Available Dengue fever is the most important arbovirus infection found in tropical regions around the world. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes, such as dengue haemorrhagic fever and dengue shock syndrome. This study analysed the genetic variability of the dengue virus serotype 1 (DENV-1 in Brazil with regard to the full-length structural genes C/prM/M/E among 34 strains isolated during epidemics that occurred in the country between 1994-2011. Virus phylogeny and time of divergence were also evaluated with only the E gene of the strains isolated from 1994-2008. An analysis of amino acid differences between these strains and the French Guiana strain (FGA/89 revealed the presence of important nonsynonymous substitutions in the amino acid sequences, including residues E297 (Met→Thr and E338 (Ser→Leu. A phylogenetic analysis of E proteins comparing the studied isolates and other strains selected from the GenBank database showed that the Brazilian DENV-1 strains since 1982 belonged to genotype V. This analysis also showed that different introductions of strains from the 1990s represented lineage replacement, with the identification of three lineages that cluster all isolates from the Americas. An analysis of the divergence time of DENV-1 indicated that the lineage circulating in Brazil emerged from an ancestral lineage that originated approximately 44.35 years ago.
Carneiro, Adriana Ribeiro; Cruz, Ana Cecília Ribeiro; Vallinoto, Marcelo; Melo, Diego de Vasconcelos; Ramos, Rommel Thiago J; Medeiros, Daniele Barbosa Almeida; Silva, Eliana Vieira Pinto da; Vasconcelos, Pedro Fernando da Costa
2012-09-01
Dengue fever is the most important arbovirus infection found in tropical regions around the world. Dispersal of the vector and an increase in migratory flow between countries have led to large epidemics and severe clinical outcomes, such as dengue haemorrhagic fever and dengue shock syndrome. This study analysed the genetic variability of the dengue virus serotype 1 (DENV-1) in Brazil with regard to the full-length structural genes C/prM/M/E among 34 strains isolated during epidemics that occurred in the country between 1994-2011. Virus phylogeny and time of divergence were also evaluated with only the E gene of the strains isolated from 1994-2008. An analysis of amino acid differences between these strains and the French Guiana strain (FGA/89) revealed the presence of important nonsynonymous substitutions in the amino acid sequences, including residues E297 (Met→Thr) and E338 (Ser→Leu). A phylogenetic analysis of E proteins comparing the studied isolates and other strains selected from the GenBank database showed that the Brazilian DENV-1 strains since 1982 belonged to genotype V. This analysis also showed that different introductions of strains from the 1990s represented lineage replacement, with the identification of three lineages that cluster all isolates from the Americas. An analysis of the divergence time of DENV-1 indicated that the lineage circulating in Brazil emerged from an ancestral lineage that originated approximately 44.35 years ago.
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.
[Emerging diseases. Crimean-Congo hemorrhagic fever].
Kuljić-Kapulica, Nada
2004-01-01
Recognized for many years in central Asia and Eastern Europe, Crimean-Congo hemorrhagic fever (CCHF) is a severe zoonotic disease which affects people coming into contact with livestock or ticks. The range of the CCHF virus is now known to extend form central Asia to India, Pakistan, Afghanistan, Iran, Iraq, the Middle East, Eastern Europe, and to most of Saharan and sub-Saharan Africa. CCHF virus is a member of the Bunyavirus family, and is classified as a Nairovirus. After an incubation period of approximately 3 to 6 days the abrupt onset of acute febrile illness occurs. The first symptoms are similar to severe influenza and include fever, headache, severe back and abdominal pain. The hemorrhagic fever manifestations occur after several days of illnesses and include petechial rash, ecchymoses, hematemmesis, and melenna. Cases typically present with some form of hepatitis. The mortality rate is 10-50% in different outbreaks with deaths typically occurring during the second week of illness. The genus Hyalomma of ixodid ticks is the most important vector of the CCHF virus. Vertebrates including birds and small animals provide excellent amplifier hosts of both the virus and the tick. The virus can be transmitted to humans by direct contact with infected animals and from person to person. Early diagnosis is possible in special laboratories using antigen detection by imunofluorescence or ELISA tests or molecular methods as PCR and antibody detection. Tick control measures need to be emphasized and utilized to prevent CCHF. This includes spraying camp sites, clothing and danger areas with acaricides or repellent. Strict isolation of patients with CCHF and a focus on barrier nursing would help to prevent nosocomial spread. Presently the vaccine is a dangerous mouse brain-derived version. Future development of a vaccine would help to prevent human infection.
Vaccine Platforms to Control Arenaviral Hemorrhagic Fevers.
Carrion, Ricardo; Bredenbeek, Peter; Jiang, Xiaohong; Tretyakova, Irina; Pushko, Peter; Lukashevich, Igor S
2012-11-20
Arenaviruses are rodent-borne emerging human pathogens. Diseases caused by these viruses, e.g., Lassa fever (LF) in West Africa and South American hemorrhagic fevers (HFs), are serious public health problems in endemic areas. We have employed replication-competent and replication-deficient strategies to design vaccine candidates potentially targeting different groups "at risk". Our leader LF vaccine candidate, the live reassortant vaccine ML29, is safe and efficacious in all tested animal models including non-human primates. In this study we showed that treatment of fatally infected animals with ML29 two days after Lassa virus (LASV) challenge protected 80% of the treated animals. In endemic areas, where most of the target population is poor and many live far from health care facilities, a single-dose vaccination with ML29 would be ideal solution. Once there is an outbreak, a fast-acting vaccine or post-exposure prophylaxis would be best. The 2(nd) vaccine technology is based on Yellow Fever (YF) 17D vaccine. We designed YF17D-based recombinant viruses expressing LASV glycoproteins (GP) and showed protective efficacy of these recombinants. In the current study we developed a novel technology to clone LASV nucleocapsid within YF17D C gene. Low immunogenicity and stability of foreign inserts must be addressed to design successful LASV/YFV bivalent vaccines to control LF and YF in overlapping endemic areas of West Africa. The 3(rd) platform is based on the new generation of alphavirus replicon virus-like-particle vectors (VLPV). Using this technology we designed VLPV expressing LASV GP with enhanced immunogenicity and bivalent VLPV expressing cross-reactive GP of Junin virus (JUNV) and Machupo virus (MACV), causative agents of Argentinian and Bolivian HF, respectively. A prime-boost regimen required for VLPV immunization might be practical for medical providers, military, lab personnel, and visitors in endemic areas.
Mweya, Clement N.; Kimera, Sharadhuli I.; Mellau, Lesakit S. B.; Mboera, Leonard E. G.
2015-01-01
Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans. Objective: To determine the abundance and distribution of mosquito vectors in relation to their potential role in the virus transmission and maintenance in disease epidemic areas of Ngorongoro district in northern Tanzania. Methods: A cross-sectional entomological investigation was carried out before the suspected RVF outbreak in October 2012. Mos...
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.
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 ...
Directory of Open Access Journals (Sweden)
Jolene Carlson
2016-10-01
Full Text Available African swine fever (ASF is a lethal hemorrhagic disease of swine caused by a double-stranded DNA virus, ASF virus (ASFV. There is no vaccine to prevent the disease and current control measures are limited to culling and restricting animal movement. Swine infected with attenuated strains are protected against challenge with a homologous virulent virus, but there is limited knowledge of the host immune mechanisms generating that protection. Swine infected with Pretoriuskop/96/4 (Pret4 virus develop a fatal severe disease, while a derivative strain lacking virulence-associated gene 9GL (Pret4Δ9GL virus is completely attenuated. Swine infected with Pret4Δ9GL virus and challenged with the virulent parental virus at 7, 10, 14, 21, and 28 days post infection (dpi showed a progressive acquisition of protection (from 40% at 7 dpi to 80% at 21 and 28 dpi. This animal model was used to associate the presence of host immune response (ASFV-specific antibody and interferon (IFN-γ responses, or specific cytokine profiles and protection against challenge. With the exception of ASFV-specific antibodies in survivors challenged at 21 and 28 dpi, no association between the parameters assessed and protection could be established. These results, encompassing data from 65 immunized swine, underscore the complexity of the system under study, suggesting that protection relies on the concurrence of different host immune mechanisms.
Hooft, van B.J.L.; Wind, de N.; Wensvoort, G.; Kimman, T.G.; Gielkens, A.L.J.; Moormann, R.J.M.
1996-01-01
The glycoprotein E (gE) locus in the genome of pseudorabies virus (PRV) was used as an insertion site for the expression of glycoprotein E1 of classical swine fever virus (CSFV). Transcription of E1 in the recombinants M401, M402 or M403 was regulated by the gD promoter of PRV, the immediate early
Zeller, H G; Cornet, J P; Camicas, J L
1994-06-01
Hyalomma (H.) marginatum rufipes ticks commonly infest birds and are potential vectors of Crimean-Congo hemorrhagic fever (CCHF) virus in west Africa. An experimental model for investigating the role of birds in the CCHF virus transmission cycle was developed. Following CCHF virus inoculation, antibodies were detected by enzyme-linked immunosorbent assay in one red-beaked hornbill and one glossy starling, but not in two laughing doves and six domestic chickens. None of the birds showed a detectable viremia. Hyalomma marginatum rufipes larvae were placed on three red-beaked hornbills and one glossy starling. These birds were then inoculated with CCHF virus (10(1.5) 50% mouse intracerebral lethal doses). Virus transmission to larvae or nymphs was obtained and seroconversions in birds were recorded. Virus was also detected in 90% of the individually tested nymphs, as well as in adults. The virus was then successfully transmitted by adult ticks to rabbits and the engorged females were allowed to oviposit. Progeny larvae were placed on another group of birds and one of three birds showed seroconversion. The cycle of transmission of virus between ticks and aviremic ground-feeding birds represent a potential reservoir and amplification mechanism of CCHF virus in west Africa.
Yellow Fever Outbreak - Kongo Central Province, Democratic Republic of the Congo, August 2016.
Otshudiema, John O; Ndakala, Nestor G; Mawanda, Elande-Taty K; Tshapenda, Gaston P; Kimfuta, Jacques M; Nsibu, Loupy-Régence N; Gueye, Abdou S; Dee, Jacob; Philen, Rossanne M; Giese, Coralie; Murrill, Christopher S; Arthur, Ray R; Kebela, Benoit I
2017-03-31
On April 23, 2016, the Democratic Republic of the Congo's (DRC's) Ministry of Health declared a yellow fever outbreak. As of May 24, 2016, approximately 90% of suspected yellow fever cases (n = 459) and deaths (45) were reported in a single province, Kongo Central Province, that borders Angola, where a large yellow fever outbreak had begun in December 2015. Two yellow fever mass vaccination campaigns were conducted in Kongo Central Province during May 25-June 7, 2016 and August 17-28, 2016. In June 2016, the DRC Ministry of Health requested assistance from CDC to control the outbreak. As of August 18, 2016, a total of 410 suspected yellow fever cases and 42 deaths were reported in Kongo Central Province. Thirty seven of the 393 specimens tested in the laboratory were confirmed as positive for yellow fever virus (local outbreak threshold is one laboratory-confirmed case of yellow fever). Although not well-documented for this outbreak, malaria, viral hepatitis, and typhoid fever are common differential diagnoses among suspected yellow fever cases in this region. Other possible diagnoses include Zika, West Nile, or dengue viruses; however, no laboratory-confirmed cases of these viruses were reported. Thirty five of the 37 cases of yellow fever were imported from Angola. Two-thirds of confirmed cases occurred in persons who crossed the DRC-Angola border at one market city on the DRC side, where ≤40,000 travelers cross the border each week on market day. Strategies to improve coordination between health surveillance and cross-border trade activities at land borders and to enhance laboratory and case-based surveillance and health border screening capacity are needed to prevent and control future yellow fever outbreaks.
Development of a membrane adsorber based capture step for the purification of yellow fever virus.
Pato, Tânia P; Souza, Marta Cristina O; Silva, Andréa N M R; Pereira, Renata C; Silva, Marlon V; Caride, Elena; Gaspar, Luciane P; Freire, Marcos S; Castilho, Leda R
2014-05-19
Yellow fever (YF) is an endemic disease in some tropical areas of South America and Africa that presents lethality rate between 20 and 50%. There is no specific treatment and to control this disease a highly effective live-attenuated egg based vaccine is widely used for travelers and residents of areas where YF is endemic. However, recent reports of rare, sometimes fatal, adverse events post-vaccination have raised concerns. In order to increase safety records, alternative strategies should be considered, such as developing a new inactivated vaccine using a cell culture based technology, capable of meeting the demands in cases of epidemic. With this goal, the production of YF virus in Vero cells grown on microcarriers and its subsequent purification by chromatographic techniques was studied. In this work we investigate the capture step of the purification process of the YF virus. At first, virus stability was studied over a wide pH range, showing best results for the alkaline region. Considering this result and the pI of the envelope protein previously determined in silico, a strong anion exchanger was considered most suitable. Due to the easy scalability, simplicity to handle, absence of diffusional limitations and suitability for virus handling of membrane adsorbers, a Q membrane was evaluated. The amount of antigen adsorbed onto the membrane was investigated within the pH range for virus stability, and the best pH for virus adsorption was considered to be 8.5. Finally, studies on gradient and step elution allowed to determine the most adequate salt concentration for washing (0.15M) and virus elution (0.30 M). Under these operating conditions, it was shown that this capture step is quite efficient, showing high product recovery (93.2±30.3%) and efficient DNA clearance (0.9±0.3 ng/dose). Copyright © 2014 Elsevier Ltd. All rights reserved.
History of U.S. Military Contributions to the Study of Viral Hemorrhagic Fevers
National Research Council Canada - National Science Library
Thomas, Stephen J; Lawler, James V; Endy, Timothy P
2005-01-01
.... The characteristics of the viral hemorrhagic fever viruses as arthropod or rodent-borne viruses that can result in human illnesses with high morbidity and mortality rates make these viruses a unique...
[Birds, mosquitoes and West Nile virus: little risk of West Nile fever in the Netherlands].
Duijster, Janneke W; Stroo, C J Arjan; Braks, Marieta A H
2016-01-01
Due to increased incidence of West Nile fever (WNF) in Europe and the rapid spread of West Nile virus (WNV) in the US, it is commonly thought that it will only be a matter of time before WNV reaches the Netherlands. However, assessing whether WNV is really a threat to the Dutch population is challenging, due to the numerous factors affecting transmission of the virus. Some of these factors are known to limit the risk of WNF in the Netherlands. This risk is determined by the interaction between the pathogen (WNV), the vectors (Culex mosquitoes), the reservoirs (birds) and the exposure of humans to infected mosquitoes. In this paper, we discuss the factors influencing introduction, establishment and spread of WNV in the Netherlands. The probability that each of these three phases will occur in the Netherlands is currently relatively small, as is the risk of WNF infection in humans in the Netherlands.
Bergeron, H C; Glas, P S; Schumann, K R
2017-12-01
African swine fever (ASF) is a highly contagious haemorrhagic disease of pigs that has the potential to cause mortality nearing 100% in naïve animals. While an outbreak of ASF in the United States' pig population (domestic and feral) has never been reported, an introduction of the disease has the potential to cause devastation to the pork industry and food security. During the recovery phase of an outbreak, an antibody detection diagnostic assay would be required to prove freedom of disease within the previously infected zone and eventually nationwide. Animals surviving an ASF infection would be considered carriers and could be identified through the persistence of ASF viral antibodies. These antibodies would demonstrate exposure to the disease and not vaccination, as there is no ASF vaccine available. A well-established commercial enzyme-linked immunosorbent assay (ELISA) detects antibodies against ASF virus (ASFV), but the diagnostic specificity of the assay had not been determined using serum samples from the pig population of the United States. This study describes an evaluation of the World Organization for Animal Health (OIE)-recommended Ingezim PPA COMPAC ELISA using a comprehensive cohort (n = 1791) of samples collected in the United States. The diagnostic specificity of the assay was determined to be 99.4% (95% confidence interval (CI): [98.9, 99.7]). The result of this study fills a gap in understanding the performance of the Ingezim PPA COMPAC ELISA in the ASF naïve pig population of the United States. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.
Seroepidemiological Studies of Crimean-Congo Hemorrhagic Fever Virus in Domestic and Wild Animals.
Directory of Open Access Journals (Sweden)
Jessica R Spengler
2016-01-01
Full Text Available Crimean-Congo hemorrhagic fever (CCHF is a widely distributed, tick-borne viral disease. Humans are the only species known to develop illness after CCHF virus (CCHFV infection, characterized by a nonspecific febrile illness that can progress to severe, often fatal, hemorrhagic disease. A variety of animals may serve as asymptomatic reservoirs of CCHFV in an endemic cycle of transmission. Seroepidemiological studies have been instrumental in elucidating CCHFV reservoirs and in determining endemic foci of viral transmission. Herein, we review over 50 years of CCHFV seroepidemiological studies in domestic and wild animals. This review highlights the role of livestock in the maintenance and transmission of CCHFV, and provides a detailed summary of seroepidemiological studies of wild animal species, reflecting their relative roles in CCHFV ecology.
African Journals Online (AJOL)
of the brain the haemorrhage is referred to as an .... The bleed is in the left basal ganglia most often originating in the putamen. Fig. 3. This 26-year-old patient presented with sudden-onset headache, right-sided ..... Early surgery versus initial.
Directory of Open Access Journals (Sweden)
Marcelo Nóbrega Litvoc
Full Text Available Summary The yellow fever (YF virus is a Flavivirus, transmitted by Haemagogus, Sabethes or Aedes aegypti mosquitoes. The disease is endemic in forest areas in Africa and Latin America leading to epizootics in monkeys that constitute the reservoir of the disease. There are two forms of YF: sylvatic, transmitted accidentally when approaching the forests, and urban, which can be perpetuated by Aedes aegypti. In Brazil, the last case of urban YF occurred in 1942. Since then, there has been an expansion of transmission areas from the North and Midwest regions to the South and Southeast. In 2017, the country faced an important outbreak of the disease mainly in the states of Minas Gerais, Espírito Santo and Rio de Janeiro. In 2018, its reach extended from Minas Gerais toward São Paulo. Yellow fever has an incubation period of 3 to 6 days and sudden onset of symptoms with high fever, myalgia, headache, nausea/vomiting and increased transaminases. The disease ranges from asymptomatic to severe forms. The most serious forms occur in around 15% of those infected, with high lethality rates. These forms lead to renal, hepatic and neurological impairment, and bleeding episodes. Treatment of mild and moderate forms is symptomatic, while severe and malignant forms depend on intensive care. Prevention is achieved by administering the vaccine, which is an effective (immunogenicity at 90-98% and safe (0.4 severe events per 100,000 doses measure. In 2018, the first transplants in the world due to YF were performed. There is also an attempt to evaluate the use of active drugs against the virus in order to reduce disease severity.
Recurrent paratyphoid fever A co-infected with hepatitis A reactivated chronic hepatitis B.
Liu, Yanling; Xiong, Yujiao; Huang, Wenxiang; Jia, Bei
2014-05-12
We report here a case of recurrent paratyphoid fever A with hepatitis A co-infection in a patient with chronic hepatitis B. A 26-year-old male patient, who was a hepatitis B virus carrier, was co-infected with Salmonella enterica serovar Paratyphi A and hepatitis A virus. The recurrence of the paratyphoid fever may be ascribed to the coexistence of hepatitis B, a course of ceftriaxone plus levofloxacin that was too short and the insensitivity of paratyphoid fever A to levofloxacin. We find that an adequate course and dose of ceftriaxone is a better strategy for treating paratyphoid fever. Furthermore, the co-infection of paratyphoid fever with hepatitis A may stimulate cellular immunity and break immunotolerance. Thus, the administration of the anti-viral agent entecavir may greatly improve the prognosis of this patient with chronic hepatitis B, and the episodes of paratyphoid fever and hepatitis A infection prompt the use of timely antiviral therapy.
Rift Valley fever (RVF) is a zoonosis of domestic ruminants in Africa. Bloodfed mosquitoes collected during the 2006-2007 RVF outbreak in Kenya were analyzed to determine the virus infection status and animal source of the bloodmeals. Bloodmeals from individual mosquito abdomens were screened for v...
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.
Geisbert, Thomas W; Lee, Amy C H; Robbins, Marjorie; Geisbert, Joan B; Honko, Anna N; Sood, Vandana; Johnson, Joshua C; de Jong, Susan; Tavakoli, Iran; Judge, Adam; Hensley, Lisa E; Maclachlan, Ian
2010-05-29
We previously showed that small interfering RNAs (siRNAs) targeting the Zaire Ebola virus (ZEBOV) RNA polymerase L protein formulated in stable nucleic acid-lipid particles (SNALPs) completely protected guineapigs when administered shortly after a lethal ZEBOV challenge. Although rodent models of ZEBOV infection are useful for screening prospective countermeasures, they are frequently not useful for prediction of efficacy in the more stringent non-human primate models. We therefore assessed the efficacy of modified non-immunostimulatory siRNAs in a uniformly lethal non-human primate model of ZEBOV haemorrhagic fever. A combination of modified siRNAs targeting the ZEBOV L polymerase (EK-1 mod), viral protein (VP) 24 (VP24-1160 mod), and VP35 (VP35-855 mod) were formulated in SNALPs. A group of macaques (n=3) was given these pooled anti-ZEBOV siRNAs (2 mg/kg per dose, bolus intravenous infusion) after 30 min, and on days 1, 3, and 5 after challenge with ZEBOV. A second group of macaques (n=4) was given the pooled anti-ZEBOV siRNAs after 30 min, and on days 1, 2, 3, 4, 5, and 6 after challenge with ZEBOV. Two (66%) of three rhesus monkeys given four postexposure treatments of the pooled anti-ZEBOV siRNAs were protected from lethal ZEBOV infection, whereas all macaques given seven postexposure treatments were protected. The treatment regimen in the second study was well tolerated with minor changes in liver enzymes that might have been related to viral infection. This complete postexposure protection against ZEBOV in non-human primates provides a model for the treatment of ZEBOV-induced haemorrhagic fever. These data show the potential of RNA interference as an effective postexposure treatment strategy for people infected with Ebola virus, and suggest that this strategy might also be useful for treatment of other emerging viral infections. Defense Threat Reduction Agency. Copyright 2010 Elsevier Ltd. All rights reserved.
Directory of Open Access Journals (Sweden)
Annika Brinkmann
2017-11-01
Full Text Available We describe the development and evaluation of a novel method for targeted amplification and Next Generation Sequencing (NGS-based identification of viral hemorrhagic fever (VHF agents and assess the feasibility of this approach in diagnostics.An ultrahigh-multiplex panel was designed with primers to amplify all known variants of VHF-associated viruses and relevant controls. The performance of the panel was evaluated via serially quantified nucleic acids from Yellow fever virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever (CCHF virus, Ebola virus, Junin virus and Chikungunya virus in a semiconductor-based sequencing platform. A comparison of direct NGS and targeted amplification-NGS was performed. The panel was further tested via a real-time nanopore sequencing-based platform, using clinical specimens from CCHF patients.The multiplex primer panel comprises two pools of 285 and 256 primer pairs for the identification of 46 virus species causing hemorrhagic fevers, encompassing 6,130 genetic variants of the strains involved. In silico validation revealed that the panel detected over 97% of all known genetic variants of the targeted virus species. High levels of specificity and sensitivity were observed for the tested virus strains. Targeted amplification ensured viral read detection in specimens with the lowest virus concentration (1-10 genome equivalents and enabled significant increases in specific reads over background for all viruses investigated. In clinical specimens, the panel enabled detection of the causative agent and its characterization within 10 minutes of sequencing, with sample-to-result time of less than 3.5 hours.Virus enrichment via targeted amplification followed by NGS is an applicable strategy for the diagnosis of VHFs which can be adapted for high-throughput or nanopore sequencing platforms and employed for surveillance or outbreak monitoring.
Brinkmann, Annika; Ergünay, Koray; Radonić, Aleksandar; Kocak Tufan, Zeliha; Domingo, Cristina; Nitsche, Andreas
2017-11-01
We describe the development and evaluation of a novel method for targeted amplification and Next Generation Sequencing (NGS)-based identification of viral hemorrhagic fever (VHF) agents and assess the feasibility of this approach in diagnostics. An ultrahigh-multiplex panel was designed with primers to amplify all known variants of VHF-associated viruses and relevant controls. The performance of the panel was evaluated via serially quantified nucleic acids from Yellow fever virus, Rift Valley fever virus, Crimean-Congo hemorrhagic fever (CCHF) virus, Ebola virus, Junin virus and Chikungunya virus in a semiconductor-based sequencing platform. A comparison of direct NGS and targeted amplification-NGS was performed. The panel was further tested via a real-time nanopore sequencing-based platform, using clinical specimens from CCHF patients. The multiplex primer panel comprises two pools of 285 and 256 primer pairs for the identification of 46 virus species causing hemorrhagic fevers, encompassing 6,130 genetic variants of the strains involved. In silico validation revealed that the panel detected over 97% of all known genetic variants of the targeted virus species. High levels of specificity and sensitivity were observed for the tested virus strains. Targeted amplification ensured viral read detection in specimens with the lowest virus concentration (1-10 genome equivalents) and enabled significant increases in specific reads over background for all viruses investigated. In clinical specimens, the panel enabled detection of the causative agent and its characterization within 10 minutes of sequencing, with sample-to-result time of less than 3.5 hours. Virus enrichment via targeted amplification followed by NGS is an applicable strategy for the diagnosis of VHFs which can be adapted for high-throughput or nanopore sequencing platforms and employed for surveillance or outbreak monitoring.
Ikegami, Tetsuro; Narayanan, Krishna; Won, Sungyong; Kamitani, Wataru; Peters, C J; Makino, Shinji
2009-09-01
Rift Valley fever virus (RVFV), which belongs to the genus Phlebovirus, family Bunyaviridae, is a negative-stranded RNA virus carrying a single-stranded, tripartite RNA genome. RVFV is an important zoonotic pathogen transmitted by mosquitoes and causes large outbreaks among ruminants and humans in Africa and the Arabian Peninsula. Human patients develop an acute febrile illness, followed by a fatal hemorrhagic fever, encephalitis, or ocular diseases. A viral nonstructural protein, NSs, is a major viral virulence factor. Past studies showed that NSs suppresses the transcription of host mRNAs, including interferon-beta mRNAs. Here we demonstrated that the NSs protein induced post-transcriptional downregulation of dsRNA-dependent protein kinase (PKR), to prevent phosphorylation of eIF2alpha and promoted viral translation in infected cells. These two biological activities of the NSs most probably have a synergistic effect in suppressing host innate immune functions and facilitate efficient viral replication in infected mammalian hosts.
Clinical practice guidelines in intracerebral haemorrhage.
Rodríguez-Yáñez, M; Castellanos, M; Freijo, M M; López Fernández, J C; Martí-Fàbregas, J; Nombela, F; Simal, P; Castillo, J; Díez-Tejedor, E; Fuentes, B; Alonso de Leciñana, M; Alvarez-Sabin, J; Arenillas, J; Calleja, S; Casado, I; Dávalos, A; Díaz-Otero, F; Egido, J A; Gállego, J; García Pastor, A; Gil-Núñez, A; Gilo, F; Irimia, P; Lago, A; Maestre, J; Masjuan, J; Martínez-Sánchez, P; Martínez-Vila, E; Molina, C; Morales, A; Purroy, F; Ribó, M; Roquer, J; Rubio, F; Segura, T; Serena, J; Tejada, J; Vivancos, J
2013-05-01
Intracerebral haemorrhage accounts for 10%-15% of all strokes; however it has a poor prognosis with higher rates of morbidity and mortality. Neurological deterioration is often observed during the first hours after onset and determines poor prognosis. Intracerebral haemorrhage, therefore, is a neurological emergency which must be diagnosed and treated properly as soon as possible. In this guide we review the diagnostic procedures and factors that influence the prognosis of patients with intracerebral haemorrhage and we establish recommendations for the therapeutic strategy, systematic diagnosis, acute treatment and secondary prevention for this condition. Copyright © 2011 Sociedad Española de Neurología. Published by Elsevier Espana. All rights reserved.
Aetiology and treatment of severe postpartum haemorrhage
DEFF Research Database (Denmark)
Edwards, Hellen
2017-01-01
This thesis is comprised of three studies focusing on severe postpartum haemorrhage (PPH). PPH is a major cause of maternal morbidity and mortality worldwide. Risk factors include retained placenta, prolonged duration of the third stage of labour, previous caesarean section, and operative vaginal...... delivery. Occurrence and development of PPH are, however, unpredictable and can sometimes give rise to massive haemorrhage or even hysterectomy and maternal death. Severe haemorrhage can lead to coagulopathy causing further haemorrhage and requiring substitution with blood transfusions. The aim...... had a cardiac arrest, and a total of 128 women (52%) required a hysterectomy. Hysterectomy was associated with increased blood loss, increased number of blood transfusions, a higher fresh frozen plasma to red blood cell ratio (p=0.010), and an increased number of red blood cells before first platelet...
Directory of Open Access Journals (Sweden)
Alimuddin Zumla
2016-06-01
Full Text Available The appearance of novel pathogens of humans with epidemic potential and high mortality rates have threatened global health security for centuries. Over the past few decades new zoonotic infectious diseases of humans caused by pathogens arising from animal reservoirs have included West Nile virus, Yellow fever virus, Ebola virus, Nipah virus, Lassa Fever virus, Hanta virus, Dengue fever virus, Rift Valley fever virus, Crimean-Congo haemorrhagic fever virus, severe acute respiratory syndrome coronavirus, highly pathogenic avian influenza viruses, Middle East Respiratory Syndrome Coronavirus, and Zika virus. The recent Ebola Virus Disease epidemic in West Africa and the ongoing Zika Virus outbreak in South America highlight the urgent need for local, regional and international public health systems to be be more coordinated and better prepared. The One Health concept focuses on the relationship and interconnectedness between Humans, Animals and the Environment, and recognizes that the health and wellbeing of humans is intimately connected to the health of animals and their environment (and vice versa. Critical to the establishment of a One Health platform is the creation of a multidisciplinary team with a range of expertise including public health officers, physicians, veterinarians, animal husbandry specialists, agriculturalists, ecologists, vector biologists, viral phylogeneticists, and researchers to co-operate, collaborate to learn more about zoonotic spread between animals, humans and the environment and to monitor, respond to and prevent major outbreaks. We discuss the unique opportunities for Middle Eastern and African stakeholders to take leadership in building equitable and effective partnerships with all stakeholders involved in human and health systems to take forward a ‘One Health’ approach to control such zoonotic pathogens with epidemic potential.
Haemorrhage in pregnancy: information given to women in Chiradzulu (Malawi
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H Kapyepye
2006-09-01
Full Text Available Advising women on , haemorrhage in pregnancy could, be viewed, as an integral aspect of maternal health care in M alawi. The WHO (1999 confirmed, that haemorrhage in pregnancy was not only a direct reason for maternal mortality but also a major cause of maternal death. The question on the nature of information that midwives and traditional birth attendants (referred to as TBA’s in the Chiradzulu district in Malawi gave with regard to haemorrhage in pregnancy, therefore arose. Research available focused on the women’s knowledge about the complications of pregnancy but not on the nature of information women received from midwives and TBA’s. This study explored and described the nature of information that was given to rural women in the Chiradzulu district by the midwives and TBA’s regarding haemorrhage in pregnancy. The findings revealed that although both the midwives and TBA’s included important information about haemorrhage in pregnancy, there were deficiencies in some critical areas. Examples of these deficiencies were the definition of haemorrhage in pregnancy; the predisposing factors for antepartum and postpartum haemorrhage and deficiencies in the nature of information on the management and referral of haemorrhaging patients. The findings provided insights into the nature of the information that was provided to the women regarding haemorrhage in pregnancy in the Chiradzulu district in Malawi. Thereafter guidelines were developed for the provision of this information. Finally a follow-up study was recommended after implementation of these guidelines in the district to evaluate the change in the nature of the information communicated to patients regarding haemorrhage by midwives and TBA’s. In this study, haemorrhage during pregnancy referred to the perinatal phase, including antepartum, intrapartum and postpartum haemorrhage.
Genomic Characterization of Crimean-Congo Hemorrhagic Fever Virus in Hyalomma Tick from Spain, 2014.
Cajimat, Maria N B; Rodriguez, Sergio E; Schuster, Isolde U E; Swetnam, Daniele M; Ksiazek, Thomas G; Habela, Miguel A; Negredo, Ana Isabel; Estrada-Peña, Agustín; Barrett, Alan D T; Bente, Dennis A
2017-10-01
Crimean-Congo hemorrhagic fever (CCHF) is a severe tick-borne disease caused by CCHF virus (CCHFV). Ticks in the genus Hyalomma are the main vectors and reservoirs of CCHFV. In Spain, CCHFV was first detected in Hyalomma ticks from Cáceres in 2010. Subsequently, two autochthonous CCHF cases were reported in August 2016. In this study, we describe the characterization of the CCHFV genome directly from Hyalomma lusitanicum collected in Cáceres in 2014. Phylogenetic analyses reveal a close relationship with clade III strains from West Africa, with an estimated divergence time of 50 years. The results of this work suggest that CCHFV has been circulating in Spain for some time, and most likely originated from West Africa.
Ultrastructural study of Rift Valley fever virus in the mouse model
Energy Technology Data Exchange (ETDEWEB)
Reed, Christopher; Steele, Keith E.; Honko, Anna; Shamblin, Joshua; Hensley, Lisa E. [United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD (United States); Smith, Darci R., E-mail: darci.smith1@us.army.mil [United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, MD (United States)
2012-09-15
Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed in the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV-host interactions and further characterize the mouse model of RVF.
Newly Discovered Ebola Virus Associated with Hemorrhagic Fever Outbreak in Uganda
Towner, Jonathan S.; Sealy, Tara K.; Khristova, Marina L.; Albariño, César G.; Conlan, Sean; Reeder, Serena A.; Quan, Phenix-Lan; Lipkin, W. Ian; Downing, Robert; Tappero, Jordan W.; Okware, Samuel; Lutwama, Julius; Bakamutumaho, Barnabas; Kayiwa, John; Comer, James A.; Rollin, Pierre E.; Ksiazek, Thomas G.; Nichol, Stuart T.
2008-01-01
Over the past 30 years, Zaire and Sudan ebolaviruses have been responsible for large hemorrhagic fever (HF) outbreaks with case fatalities ranging from 53% to 90%, while a third species, Côte d'Ivoire ebolavirus, caused a single non-fatal HF case. In November 2007, HF cases were reported in Bundibugyo District, Western Uganda. Laboratory investigation of the initial 29 suspect-case blood specimens by classic methods (antigen capture, IgM and IgG ELISA) and a recently developed random-primed pyrosequencing approach quickly identified this to be an Ebola HF outbreak associated with a newly discovered ebolavirus species (Bundibugyo ebolavirus) distantly related to the Côte d'Ivoire ebolavirus found in western Africa. Due to the sequence divergence of this new virus relative to all previously recognized ebolaviruses, these findings have important implications for design of future diagnostic assays to monitor Ebola HF disease in humans and animals, and ongoing efforts to develop effective antivirals and vaccines. PMID:19023410
Ultrastructural study of Rift Valley fever virus in the mouse model
International Nuclear Information System (INIS)
Reed, Christopher; Steele, Keith E.; Honko, Anna; Shamblin, Joshua; Hensley, Lisa E.; Smith, Darci R.
2012-01-01
Detailed ultrastructural studies of Rift Valley fever virus (RVFV) in the mouse model are needed to develop and characterize a small animal model of RVF for the evaluation of potential vaccines and therapeutics. In this study, the ultrastructural features of RVFV infection in the mouse model were analyzed. The main changes in the liver included the presence of viral particles in hepatocytes and hepatic stem cells accompanied by hepatocyte apoptosis. However, viral particles were observed rarely in the liver; in contrast, particles were extremely abundant in the CNS. Despite extensive lymphocytolysis, direct evidence of viral replication was not observed in the lymphoid tissue. These results correlate with the acute-onset hepatitis and delayed-onset encephalitis that are dominant features of severe human RVF, but suggest that host immune-mediated mechanisms contribute significantly to pathology. The results of this study expand our knowledge of RVFV–host interactions and further characterize the mouse model of RVF.
Directory of Open Access Journals (Sweden)
Yuko Ohagi
2014-01-01
Full Text Available Severe fever with thrombocytopenia syndrome (SFTS is an emerging infectious and hemorrhagic disease recently described in China and western Japan. A 71-year-old healthy Japanese woman noticed a tick biting her after harvesting in an orchard and removed it herself. She developed diarrhea, anorexia, and chills eight days later. Because these symptoms continued, she visited a primary care physician 6 days after the onset. Laboratory data revealed thrombocytopenia, leukocytopenia, and elevated liver enzymes. She was then referred to our hospital. Although not completely fulfilling the diagnostic criteria used in a retrospective study in Japan, SFTS was suspected, and we detected SFTS virus in the patient’s blood using RT-PCR. However, she recovered without intensive treatment and severe complications 13 days after the onset. In this report, we present a mild clinical course of SFTS virus infection in Japan in detail.
Ecological niche modelling of Rift Valley fever virus vectors in Baringo, Kenya
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Alfred O. Ochieng
2016-11-01
Full Text Available Background: Rift Valley fever (RVF is a vector-borne zoonotic disease that has an impact on human health and animal productivity. Here, we explore the use of vector presence modelling to predict the distribution of RVF vector species under climate change scenario to demonstrate the potential for geographic spread of Rift Valley fever virus (RVFV. Objectives: To evaluate the effect of climate change on RVF vector distribution in Baringo County, Kenya, with an aim of developing a risk map for spatial prediction of RVF outbreaks. Methodology: The study used data on vector presence and ecological niche modelling (MaxEnt algorithm to predict the effect of climatic change on habitat suitability and the spatial distribution of RVF vectors in Baringo County. Data on species occurrence were obtained from longitudinal sampling of adult mosquitoes and larvae in the study area. We used present (2000 and future (2050 Bioclim climate databases to model the vector distribution. Results: Model results predicted potential suitable areas with high success rates for Culex quinquefasciatus, Culex univitattus, Mansonia africana, and Mansonia uniformis. Under the present climatic conditions, the lowlands were found to be highly suitable for all the species. Future climatic conditions indicate an increase in the spatial distribution of Cx. quinquefasciatus and M. africana. Model performance was statistically significant. Conclusion: Soil types, precipitation in the driest quarter, precipitation seasonality, and isothermality showed the highest predictive potential for the four species.
Campbell, Lindsay P; Alexander, Alana M
2017-09-01
Rift Valley fever virus (RVFV) is a vector-borne, zoonotic disease that affects humans, wild ungulates, and domesticated livestock in Africa and the Arabian Peninsula. Rift Valley fever virus exhibits interepizootic and epizootic phases, the latter defined by widespread virus occurrence in domesticated livestock. Kenya appears to be particularly vulnerable to epizootics, with 11 outbreaks occurring between 1951 and 2007. The mosquito species Aedes mcintoshi (subgenus Neomelaniconion) is an important primary vector for RVFV in Kenya. Here, we investigate associations between genetic diversity and differentiation of one regional subclade of Ae. mcintoshi in Northeastern Kenya with environmental variables, using a multivariate statistical approach. Using CO1 (cytochrome oxidase subunit 1) sequence data deposited in GenBank, we found no evidence of isolation by distance contributing to genetic differentiation across the study area. However, we did find significant CO1 subpopulation structure and associations with recent mean precipitation values. In addition, variation in genetic diversity across our seven sample sites was associated with both precipitation and percentage clay in the soil. The large number of haplotypes found in this data set indicates that a great deal of diversity remains unsampled in this region. Additional sampling across a larger geographic area, combined with next-generation sequencing approaches that better characterize the genome, would provide a more robust assessment of genetic diversity and differentiation. Further understanding of the genetic structure of Ae. mcintoshi could provide useful information regarding the potential for RVFV to spread across East African landscapes. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Wu, Xiaodong; Qi, Xian; Liang, Mifang; Li, Chuan; Cardona, Carol J; Li, Dexin; Xing, Zheng
2014-06-01
Severe fever with thrombocytopenia syndrome (SFTS) virus is an emerging bunyavirus that causes a hemorrhagic fever with a high mortality rate. The virus is likely tick-borne and replicates primarily in hemopoietic cells, which may lead to disregulation of proinflammatory cytokine induction and loss of leukocytes and platelets. The viral genome contains L, M, and S segments encoding a viral RNA polymerase, glycoproteins G(n) and G(c), nucleoprotein (NP), and a nonstructural S segment (NSs) protein. NSs protein is involved in the regulation of host innate immune responses and suppression of IFNβ-promoter activities. In this article, we demonstrate that NSs protein can form viroplasm-like structures (VLSs) in infected and transfected cells. NSs protein molecules interact with one another, interact with NP, and were associated with viral RNA in infected cells, suggesting that NSs protein may be involved in viral replication. Furthermore, we observed that NSs-formed VLS colocalized with lipid droplets and that inhibitors of fatty acid biosynthesis decreased VLS formation or viral replication in transfected and infected cells. Finally, we have demonstrated that viral dsRNAs were also localized in VLS in infected cells, suggesting that NSs-formed VLS may be implicated in the replication of SFTS bunyavirus. These findings identify a novel function of nonstructural NSs in SFTSV-infected cells where it is a scaffolding component in a VLS functioning as a virus replication factory. This function is in addition to the role of NSs protein in modulating host responses that will broaden our understanding of viral pathogenesis of phleboviruses. © FASEB.
Monath, Thomas P.; Seligman, Stephen J.; Robertson, James S.; Guy, Bruno; Hayes, Edward B.; Condit, Richard C.; Excler, Jean Louis; Mac, Lisa Marie; Carbery, Baevin; Chen, Robert T
2015-01-01
The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety of live, recombinant viral vaccines incorporating genes from heterologous viruses inserted into the backbone of another virus (so-called “chimeric virus vaccines”). Many viral vector vaccines are in advanced clinical trials. The first such vaccine to be approved for marketing (to date in Australia, Thailand, Malaysia, and the Philippines) is a vaccine against the flavivirus Japanese encephalitis (JE), which employs a licensed vaccine (yellow fever 17D) as a vector. In this vaccine, two envelope proteins (prM-E) of YF 17D virus were replaced by the corresponding genes of JE virus, with additional attenuating mutations incorporated into the JE gene inserts. Similar vaccines have been constructed by inserting prM-E genes of dengue and West Nile into YF 17D virus and are in late stage clinical studies. The dengue vaccine is, however, more complex in that it requires a mixture of four live vectors each expressing one of the four dengue serotypes. This vaccine has been evaluated in multiple clinical trials. No significant safety concerns have been found. The Phase 3 trials met their endpoints in terms of overall reduction of confirmed dengue fever, and, most importantly a significant reduction in severe dengue and hospitalization due to dengue. However, based on results that have been published so far, efficacy in preventing serotype 2 infection is less than that for the other three serotypes. In the development of these chimeric vaccines, an important series of comparative studies of safety and efficacy were made using the parental YF 17D vaccine virus as a benchmark. In this paper, we use a standardized template describing the key characteristics of the novel flavivirus vaccine vectors, in comparison to the parental YF 17D vaccine. The template facilitates scientific discourse among key stakeholders by increasing the transparency and comparability of
Monath, Thomas P; Seligman, Stephen J; Robertson, James S; Guy, Bruno; Hayes, Edward B; Condit, Richard C; Excler, Jean Louis; Mac, Lisa Marie; Carbery, Baevin; Chen, Robert T
2015-01-01
The Brighton Collaboration Viral Vector Vaccines Safety Working Group (V3SWG) was formed to evaluate the safety of live, recombinant viral vaccines incorporating genes from heterologous viruses inserted into the backbone of another virus (so-called "chimeric virus vaccines"). Many viral vector vaccines are in advanced clinical trials. The first such vaccine to be approved for marketing (to date in Australia, Thailand, Malaysia, and the Philippines) is a vaccine against the flavivirus, Japanese encephalitis (JE), which employs a licensed vaccine (yellow fever 17D) as a vector. In this vaccine, two envelope proteins (prM-E) of YF 17D virus were exchanged for the corresponding genes of JE virus, with additional attenuating mutations incorporated into the JE gene inserts. Similar vaccines have been constructed by inserting prM-E genes of dengue and West Nile into YF 17D virus and are in late stage clinical studies. The dengue vaccine is, however, more complex in that it requires a mixture of four live vectors each expressing one of the four dengue serotypes. This vaccine has been evaluated in multiple clinical trials. No significant safety concerns have been found. The Phase 3 trials met their endpoints in terms of overall reduction of confirmed dengue fever, and, most importantly a significant reduction in severe dengue and hospitalization due to dengue. However, based on results that have been published so far, efficacy in preventing serotype 2 infection is less than that for the other three serotypes. In the development of these chimeric vaccines, an important series of comparative studies of safety and efficacy were made using the parental YF 17D vaccine virus as a benchmark. In this paper, we use a standardized template describing the key characteristics of the novel flavivirus vaccine vectors, in comparison to the parental YF 17D vaccine. The template facilitates scientific discourse among key stakeholders by increasing the transparency and comparability of
Haemorrhagic pituitary tumours
International Nuclear Information System (INIS)
Lazaro, C.M.; Philippine General Hospital, Manila; Guo, W.Y.; Sami, M.; Hindmarsch, T.; Ericson, K.; Hulting, A.L.; Wersaell, J.
1994-01-01
In a group of 69 patients with pituitary tumours, 12 were found to have evidence of intratumoral haemorrhage on MRI, characterized by high signal intensity on short TR/TE sequences. This was verified in all but 1 patient. The majority of the bleedings occurred in macroadenomas. Five (42%) were prolactinomas and 4 (33%) were non-functioning adenomas. There were 2 GH- and 1 ACTH-secreting tumours. All 5 patients with prolactinomas were on bromocriptine medication. Two of the patients had a clinical picture of pituitary apoplexy. The haemorrhage was not large enough to prompt surgery in any of the patients. However, surgical verification of the diagnosis was obtained in 5 cases, while 6 patients were examined with follow-up MRI. (orig.)
Tsai, T F; Lazuick, J S; Ngah, R W; Mafiamba, P C; Quincke, G; Monath, T P
1987-01-01
A cluster of fatal hepatitis cases in northern Cameroon in 1984 stimulated a field investigation to rule out an epidemic of yellow fever. A serosurvey of villages in the extreme north of the country, in a Sudan savanna (SS) phytogeographical zone, disclosed no evidence of recent yellow fever infection. However, further south, in a Guinea savanna (GS) phytogeographical zone, serological evidence was found of endemic yellow fever virus transmission. The results indicate a potential for epidemic spread of yellow fever virus from the southern GS zone to the nothern SS zone of Cameroon, where immunity in the population was low.
Hereditary haemorrhagic telangiectasia
DEFF Research Database (Denmark)
Kjeldsen, A D; Vase, P; Green, A
1999-01-01
Hereditary haemorrhagic telangiectasia (HHT) is a dominantly inherited disease characterized by telangiectatic lesions. The disease manifestations are variable and include epistaxis, gastrointestinal bleeding, pulmonary arteriovenous malformations and cerebral arteriovenous malformations. Early...
Limited replication of yellow fever 17DD and 17D-Dengue recombinant viruses in rhesus monkeys
Directory of Open Access Journals (Sweden)
Gisela F. Trindade
2008-06-01
Full Text Available For the development of safe live attenuated flavivirus vaccines one of the main properties to be established is viral replication. We have used real-time reverse transcriptase-polymerase chain reaction and virus titration by plaque assay to determine the replication of yellow fever 17DD virus (YFV 17DD and recombinant yellow fever 17D viruses expressing envelope proteins of dengue virus serotypes 2 and 4 (17D-DENV-2 and 17D-DENV-4. Serum samples from rhesus monkeys inoculated with YFV 17DD and 17D-DENV chimeras by intracerebral or subcutaneous route were used to determine and compare the viremia induced by these viruses. Viral load quantification in samples from monkeys inoculated by either route with YFV 17DD virus suggested a restricted capability of the virus to replicate reaching not more than 2.0 log10 PFU mL-1 or 3.29 log10 copies mL-1. Recombinant 17D-dengue viruses were shown by plaquing and real-time PCR to be as attenuated as YF 17DD virus with the highest mean peak titer of 1.97 log10 PFU mL-1 or 3.53 log10 copies mL-1. These data serve as a comparative basis for the characterization of other 17D-based live attenuated candidate vaccines against other diseases.Uma das principais propriedades a serem estabelecidas para o desenvolvimento de vacinas seguras e atenuadas de flavivirus,é a taxa de replicação viral. Neste trabalho, aplicamos a metodologia de amplificação pela reação em cadeia da polimerase em tempo real e titulação viral por plaqueamento para determinação da replicação do vírus 17DD (FA 17DD e recombinantes, expressando proteínas do envelope de dengue sorotipos 2 e 4 (17D-DENV-2 e 17D-DENV-4. As amostras de soros de macacos inoculados por via intracerebral ou subcutânea com FA 17DD ou 17D-DENV foram usadas para determinar e comparar a viremia induzida por estes vírus. A quantificação da carga viral em amostras de macacos inoculados por ambas as vias com FA 17DD sugere restrita capacidade de replicação com
Host genetic diversity enables Ebola hemorrhagic fever pathogenesis and resistance.
Rasmussen, Angela L; Okumura, Atsushi; Ferris, Martin T; Green, Richard; Feldmann, Friederike; Kelly, Sara M; Scott, Dana P; Safronetz, David; Haddock, Elaine; LaCasse, Rachel; Thomas, Matthew J; Sova, Pavel; Carter, Victoria S; Weiss, Jeffrey M; Miller, Darla R; Shaw, Ginger D; Korth, Marcus J; Heise, Mark T; Baric, Ralph S; de Villena, Fernando Pardo-Manuel; Feldmann, Heinz; Katze, Michael G
2014-11-21
Existing mouse models of lethal Ebola virus infection do not reproduce hallmark symptoms of Ebola hemorrhagic fever, neither delayed blood coagulation and disseminated intravascular coagulation nor death from shock, thus restricting pathogenesis studies to nonhuman primates. Here we show that mice from the Collaborative Cross panel of recombinant inbred mice exhibit distinct disease phenotypes after mouse-adapted Ebola virus infection. Phenotypes range from complete resistance to lethal disease to severe hemorrhagic fever characterized by prolonged coagulation times and 100% mortality. Inflammatory signaling was associated with vascular permeability and endothelial activation, and resistance to lethal infection arose by induction of lymphocyte differentiation and cellular adhesion, probably mediated by the susceptibility allele Tek. These data indicate that genetic background determines susceptibility to Ebola hemorrhagic fever. Copyright © 2014, American Association for the Advancement of Science.
Directory of Open Access Journals (Sweden)
Jacqueline Kasiiti Lichoti
2014-01-01
Full Text Available Rift Valley fever virus causes an important zoonotic disease of humans and small ruminants in Eastern Africa and is spread primarily by a mosquito vector. In this region, it occurs as epizootics that typically occur at 5–15-year intervals associated with unusual rainfall events. It has hitherto been known that the virus is maintained between outbreaks in dormant eggs of the mosquito vector and this has formed the basis of understanding of the epidemiology and control strategies of the disease. We show here that seroconversion and sporadic acute disease do occur during the interepidemic periods (IEPs in the absence of reported cases in livestock or humans. The finding indicates that previously undetected low-level virus transmission during the IEPs does occur and that epizootics may also be due to periodic expansion of mosquito vectors in the presence of both circulating virus and naïve animals.
Seroprevalence of Infections with Dengue, Rift Valley Fever and Chikungunya Viruses in Kenya, 2007.
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Caroline Ochieng
Full Text Available Arthropod-borne viruses are a major constituent of emerging infectious diseases worldwide, but limited data are available on the prevalence, distribution, and risk factors for transmission in Kenya and East Africa. In this study, we used 1,091 HIV-negative blood specimens from the 2007 Kenya AIDS Indicator Survey (KAIS 2007 to test for the presence of IgG antibodies to dengue virus (DENV, chikungunya virus (CHIKV and Rift Valley fever virus (RVFV.The KAIS 2007 was a national population-based survey conducted by the Government of Kenya to provide comprehensive information needed to address the HIV/AIDS epidemic. Antibody testing for arboviruses was performed on stored blood specimens from KAIS 2007 through a two-step sandwich IgG ELISA using either commercially available kits or CDC-developed assays. Out of the 1,091 samples tested, 210 (19.2% were positive for IgG antibodies against at least one of the three arboviruses. DENV was the most common of the three viruses tested (12.5% positive, followed by RVFV and CHIKV (4.5% and 0.97%, respectively. For DENV and RVFV, the participant's province of residence was significantly associated (P≤.01 with seropositivity. Seroprevalence of DENV and RVFV increased with age, while there was no correlation between province of residence/age and seropositivity for CHIKV. Females had twelve times higher odds of exposure to CHIK as opposed to DENV and RVFV where both males and females had the same odds of exposure. Lack of education was significantly associated with a higher odds of previous infection with either DENV or RVFV (p <0.01. These data show that a number of people are at risk of arbovirus infections depending on their geographic location in Kenya and transmission of these pathogens is greater than previously appreciated. This poses a public health risk, especially for DENV.
Rift Valley fever potential mosquito vectors and their infection status ...
African Journals Online (AJOL)
Background: Rift Valley fever (RVF) is a mosquito-borne viral zoonotic disease. Rift Valley fever virus (RVFV) has been isolated from more than 40 species of mosquitoes from eight genera. This study was conducted to determine the abundance of potential mosquito vectors and their RVFV infection status in Ngorongoro ...
Tucakov, Anna Katharina; Yavuz, Sabine; Schürmann, Eva-Maria; Mischler, Manjula; Klingebeil, Anne; Meyers, Gregor
2018-01-01
The classical swine fever virus (CSFV) represents one of the most important pathogens of swine. The CSFV glycoprotein E rns is an essential structural protein and an important virulence factor. The latter is dependent on the RNase activity of this envelope protein and, most likely, its secretion from the infected cell. A further important feature with regard to its function as a virulence factor is the formation of disulfide-linked E rns homodimers that are found in virus-infected cells and virions. Mutant CSFV lacking cysteine (Cys) 171, the residue responsible for intermolecular disulfide bond formation, were found to be attenuated in pigs (Tews BA, Schürmann EM, Meyers G. J Virol 2009;83:4823-4834). In the course of an animal experiment with such a dimerization-negative CSFV mutant, viruses were reisolated from pigs that contained a mutation of serine (Ser) 209 to Cys. This mutation restored the ability to form disulphide-linked E rns homodimers. In transient expression studies E rns mutants carrying the S209C change were found to form homodimers with about wt efficiency. Also the secretion level of the mutated proteins was equivalent to that of wt E rns . Virus mutants containing the Cys171Ser/Ser209Cys configuration exhibited wt growth rates and increased virulence when compared with the Cys171Ser mutant. These results provide further support for the connection between CSFV virulence and E rns dimerization.
DEFF Research Database (Denmark)
Oleksiewicz, Martin B.; Rasmussen, Thomas Bruun; Normann, Preben
2003-01-01
The classical swine fever (CSF) epidemic in the Netherlands in 1997-1998 lasted 14 months, during which 429 infected and 1300 at risk herds were culled, at an estimated economical cost of 2 billion US dollars. Despite the overwhelming scale of the epizootic, the CSF virus (CSFV) strain causing th...
Ultrasonically detectable cerebellar haemorrhage in preterm infants.
LENUS (Irish Health Repository)
McCarthy, Lisa Kenyon
2011-07-01
To determine the frequency and pattern of cerebellar haemorrhage (CBH) on routine cranial ultrasound (cUS) imaging in infants of ≤32 weeks gestation, and to investigate how extremely preterm infants with CBH differ from those with severe intraventricular haemorrhage (IVH).
Rift Valley fever virus NSS gene expression correlates with a defect in nuclear mRNA export.
Copeland, Anna Maria; Van Deusen, Nicole M; Schmaljohn, Connie S
2015-12-01
We investigated the localization of host mRNA during Rift Valley fever virus (RVFV) infection. Fluorescence in situ hybridization revealed that infection with RVFV altered the localization of host mRNA. mRNA accumulated in the nuclei of RVFV-infected but not mock-infected cells. Further, overexpression of the NSS gene, but not the N, GN or NSM genes correlated with mRNA nuclear accumulation. Nuclear accumulation of host mRNA was not observed in cells infected with a strain of RVFV lacking the gene encoding NSS, confirming that expression of NSS is likely responsible for this phenomenon. Published by Elsevier Inc.
DEFF Research Database (Denmark)
Fahnøe, Ulrik; Pedersen, Anders Gorm; Höper, Dirk
2013-01-01
to the consensus sequence. Additionally, we got an average sequence depth for the genome of 4000 for the Iontorrent PGM and 400 for the FLX platform making the mapping suitable for single nucleotide variant (SNV) detection. The analysis revealed a single non-silent SNV A10665G leading to the amino acid change D......Next Generation Sequencing (NGS) is becoming more adopted into viral research and will be the preferred technology in the years to come. We have recently sequenced several strains of Classical Swine Fever Virus (CSFV) by NGS on both Genome Sequencer FLX (GS FLX) and Iontorrent PGM platforms...
Rift Valley fever virus NSs protein functions and the similarity to other bunyavirus NSs proteins.
Ly, Hoai J; Ikegami, Tetsuro
2016-07-02
Rift Valley fever is a mosquito-borne zoonotic disease that affects both ruminants and humans. The nonstructural (NS) protein, which is a major virulence factor for Rift Valley fever virus (RVFV), is encoded on the S-segment. Through the cullin 1-Skp1-Fbox E3 ligase complex, the NSs protein promotes the degradation of at least two host proteins, the TFIIH p62 and the PKR proteins. NSs protein bridges the Fbox protein with subsequent substrates, and facilitates the transfer of ubiquitin. The SAP30-YY1 complex also bridges the NSs protein with chromatin DNA, affecting cohesion and segregation of chromatin DNA as well as the activation of interferon-β promoter. The presence of NSs filaments in the nucleus induces DNA damage responses and causes cell-cycle arrest, p53 activation, and apoptosis. Despite the fact that NSs proteins have poor amino acid similarity among bunyaviruses, the strategy utilized to hijack host cells are similar. This review will provide and summarize an update of recent findings pertaining to the biological functions of the NSs protein of RVFV as well as the differences from those of other bunyaviruses.
CLINICAL AND LABORATORY PROFILE OF DENGUE FEVER
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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
Postpartum haemorrhage: a preventable cause of maternal mortality
International Nuclear Information System (INIS)
Shaheen, B.; Hassan, L.
2007-01-01
To assess the preventable predictors of severe postpartum haemorrhage and the adverse outcome associated with it. All the admitted patients who developed severe postpartum haemorrhage (>1500 ml) were included in the study. Clinical and sociodemographic data was obtained along with results of investigations to categorize the complications encountered. Odds ratio (OR) and 95% confidence intervals were determined. During the study period, 75 out of 4683 obstetrical admissions, developed severe postpartum haemorrhage (1.6 %). About 65% of the patients were admitted with some other complications including obstructed labour, antepartum haemorrhage and eclampsia. The risk factors were grand multiparity (OR=3.4), pre-eclampsia (OR=2.75), antepartum haemorrhage (OR=13.35), active labour of more than 10 hours (OR=46.92), twin delivery (OR=3.25), instrumental delivery (OR=8.62) and caesarean section (OR=9.74). Maternal mortality in these cases was 2.66% and residual morbidity being 40%. Birth attendant other than doctor and delivery outside the study unit were significantly associated with the adverse outcome in these patients. Maternal outcome associated with postpartum haemorrhage is a function of care given during labour and postnatal period with early diagnosis and management of the complication and its risk factors, being the key of good maternal outcome. (author)
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Izurieta RO
2018-04-01
Full Text Available Ricardo O Izurieta,1 David A DeLacure,1 Andres Izurieta,2 Ismael A Hoare,1 Miguel Reina Ortiz,1,3 1Department of Global Health, College of Public Health, University of South Florida, Tampa, FL, USA; 2Department of Computer Science and Engineering, College of Engineering, University of South Florida, Tampa, FL, USA; 3Fundación Raíces, Esmeraldas, Ecuador Abstract: Mayaro fever is an emerging acute viral disease endemic in Central and South America. Mayaro virus (MAYV is classified in the Semliki Forest virus antigenic complex and shares similarities with the alphavirus Chikungunya virus and the flavivirus Dengue virus. MAYV is an arbovirus transmitted by Haemagogus janthinomys, with competence also demonstrated in Aedes aegypti, Aedes scapularis, and Anopheles quadrimaculatus. Outbreaks and small epidemics of Mayaro fever have occurred in several countries in northern South America and the Caribbean. In addition, travel-associated cases have been reported in European nationals returning from endemic areas. Clinical features of Mayaro fever include fever, chills, persistent arthralgia, retro-orbital pain, maculopapular rash, itching, dizziness, and, rarely, lymphadenopathy. Methods of control for MAYV are similar to those used for other sylvatic arboviruses. Although MAYV was discovered as long ago as the 1950s and continues to be prevalent in the tropical areas of the Americas, it remains neglected and under-studied. This paper provides a thorough and current review of the published MAYV literature ranging from its original description to modern outbreaks, and from the basic virus characteristics to the clinical and epidemiological aspects of this disease. Keywords: Mayaro virus, emerging arbovirus, dengue-like virus, arthrogenic virus
... is caused by a virus transmitted primarily by Aedes mosquitoes. People with Zika virus disease can have symptoms including mild fever, skin ... framework. Q&A: Zika virus and complication ... mosquito from the Aedes genus, mainly Aedes aegypti in tropical regions. Aedes ...
CD8+ T Cells Complement Antibodies in Protecting against Yellow Fever Virus
DEFF Research Database (Denmark)
Bassi, Maria R; Kongsgaard, Michael; Steffensen, Maria A
2015-01-01
The attenuated yellow fever (YF) vaccine (YF-17D) was developed in the 1930s, yet little is known about the protective mechanisms underlying its efficiency. In this study, we analyzed the relative contribution of cell-mediated and humoral immunity to the vaccine-induced protection in a murine model...... of YF-17D infection. Using different strains of knockout mice, we found that CD4(+) T cells, B cells, and Abs are required for full clinical protection of vaccinated mice, whereas CD8(+) T cells are dispensable for long-term survival after intracerebral challenge. However, by analyzing the immune...... response inside the infected CNS, we observed an accelerated T cell influx into the brain after intracerebral challenge of vaccinated mice, and this T cell recruitment correlated with improved virus control in the brain. Using mice deficient in B cells we found that, in the absence of Abs, YF vaccination...
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Adriana S Azevedo
Full Text Available The dengue envelope glycoprotein (E is the major component of virion surface and its ectodomain is composed of domains I, II and III. This protein is the main target for the development of a dengue vaccine with induction of neutralizing antibodies. In the present work, we tested two different vaccination strategies, with combined immunizations in a prime/booster regimen or simultaneous inoculation with a DNA vaccine (pE1D2 and a chimeric yellow fever/dengue 2 virus (YF17D-D2. The pE1D2 DNA vaccine encodes the ectodomain of the envelope DENV2 protein fused to t-PA signal peptide, while the YF17D-D2 was constructed by replacing the prM and E genes from the 17D yellow fever vaccine virus by those from DENV2. Balb/c mice were inoculated with these two vaccines by different prime/booster or simultaneous immunization protocols and most of them induced a synergistic effect on the elicited immune response, mainly in neutralizing antibody production. Furthermore, combined immunization remarkably increased protection against a lethal dose of DENV2, when compared to each vaccine administered alone. Results also revealed that immunization with the DNA vaccine, regardless of the combination with the chimeric virus, induced a robust cell immune response, with production of IFN-γ by CD8+ T lymphocytes.
Mechanism of fever induction in rabbits.
Siegert, R; Philipp-Dormston, W K; Radsak, K; Menzel, H
1976-01-01
Three exogenous pyrogens (Escherichia coli lipopolysaccharide, synthetic double-stranded ribonucleic acid. Newcastle disease virus) were compared with respect to their mechanisms of fever induction in rabbits. All inducers stimulated the production of an endogenous pyrogen demonstrated in the blood as well as prostaglandins of the E group, and of cyclic adenosine 3',5'-monophosphate in the cerebrospinal fluid. The concentrations of these compounds were elevated approximately twofold as compared to the controls. Independently of the mode of induction, the fever reaction could be prevented by pretreatment with 5 mg of cycloheximide per kg, although the three fever mediators were induced as in febrile animals. Consequently, at least one additional fever mediator that is sensitive to a 30 to 50% inhibition of protein synthesis by cycloheximide has to be postulated. The comparable reactions of the rabbits after administration of different pyrogens argues for a similar fever mechanism. In contrast to fever induction there was no stimulation of endogenous pyrogen, prostaglandins of the E group, and cyclic adenosine 3',5'-monophosphate in hyperthermia as a consequence of exposure of the animals to exogenous overheating. Furthermore, hyperthermia could not be prevented by cycloheximide. PMID:185148
Olivary degeneration after cerebellar or brain stem haemorrhage: MRI
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Uchino, A. (Dept. of Radiology, Kyushu Univ. Hospital, Fukuoka (Japan) Dept. of Radiology, Kyushu Rosai Hospital, Kitakyushu (Japan)); Hasuo, K. (Dept. of Radiology, Kyushu Univ. Hospital, Fukuoka (Japan)); Uchida, K. (Dept. of Radiology, Kyushu Rosai Hospital, Kitakyushu (Japan)); Matsumoto, S. (Dept. of Radiology, Kyushu Univ. Hospital, Fukuoka (Japan)); Tsukamoto, Y. (Dept. of Radiology, Kyushu Rosai Hospital, Kitakyushu (Japan)); Ohno, M. (Dept. of Radiology, Kyushu Rosai Hospital, Kitakyushu (Japan)); Masuda, K. (Dept. of Radiology, Kyushu Univ. Hospital, Fukuoka (Japan))
1993-05-01
Magnetic resonance (MR) images of seven patients with olivary degeneration caused by cerebellar or brain stem haemorrhages were reviewed. In four patients with cerebellar haemorrhage, old haematomas were identified as being located in the dentate nucleus; the contralateral inferior olivary nuclei were hyperintense on proton-density- and T2-weighted images. In two patients with pontine haemorrhages, the old haematomas were in the tegmentum and the ipsilateral inferior olivary nuclei, which were hyperintense. In one case of midbrain haemorrhage, the inferior olivary nuclei were hyperintense bilaterally. The briefest interval from the ictus to MRI was 2 months. Hypertrophic olivary nuclei were observed only at least 4 months after the ictus. Olivary degeneration after cerebellar or brain stem haemorrhage should not be confused with ischaemic, neoplastic, or other primary pathological conditions of the medulla. (orig.)
Simultaneous circulation of genotypes I and III of dengue virus 3 in Colombia
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Domingo Cristina
2008-09-01
Full Text Available Abstract Background Dengue is a major health problem in tropical and subtropical regions. In Colombia, dengue viruses (DENV cause about 50,000 cases annually, 10% of which involve Dengue Haemorrhagic Fever/Dengue Shock Syndrome. The picture is similar in other surrounding countries in the Americas, with recent outbreaks of severe disease, mostly associated with DENV serotype 3, strains of the Indian genotype, introduced into the Americas in 1994. Results The analysis of the 3'end (224 bp of the envelope gene from 32 DENV-3 strains recently recovered in Colombia confirms the circulation of the Indian genotype, and surprisingly the co-circulation of an Asian-Pacific genotype only recently described in the Americas. Conclusion These results have important implications for epidemiology and surveillance of DENV infection in Central and South America. Molecular surveillance of the DENV genotypes infecting humans could be a very valuable tool for controlling/mitigating the impact of the DENV infection.