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Sample records for nile virus seroprevalence

  1. West Nile Virus: Seroprevalence in Animals in Palestine and Israel.

    Science.gov (United States)

    Azmi, Kifaya; Tirosh-Levy, Sharon; Manasrah, Mu'taz; Mizrahi, Rotem; Nasereddin, Abed; Al-Jawabreh, Amer; Ereqat, Suheir; Abdeen, Ziad; Lustig, Yaniv; Gelman, Boris; Schvartz, Gili; Steinman, Amir

    2017-08-01

    West Nile virus (WNV) epidemiological situation in Israel and Palestine, due to their unique location, draws attention following to the global spread of West Nile fever (WNF). Although much information is available from Israel on clinical cases and prevalence of WNV, clinical cases are rarely reported in Palestine, and prevalence is not known. The objectives of this study were to determine WNV seroprevalence in various domestic animals in Palestine and to reevaluate current seroprevalence, force of infection, and risk factors for WNV exposure in horses in Israel. Sera samples were collected from 717 animals from Palestine and Israel (460 horses, 124 donkeys, 3 mules, 50 goats, 45 sheep, and 35 camels). Two hundred and ten horses were sampled twice. The level of WNV antibodies was determined using commercial Enzyme-linked Immunosorbent Assay (ELISA) Kit. Seroprevalence in equids was 73%. Seroprevalence in Israel (84.6%) was significantly higher than in Palestine (48.6%). Seroprevalence in horses (82.6%) was significantly higher than in donkeys and mules (39.3%). Multivariable statistical analysis showed that geographical area, landscape features (altitude), environmental factors (land surface temperature during the day [LSTD]), species, and age significantly influenced WNV seroprevalence. Fourteen of 95 (14.7%) sheep and goats and 14/35 camels (40%) sampled in Palestine were seropositive for WNV. Of the horses that were sampled twice, 82.8% were seropositive for WNV at the first sampling, and all remained seropositive. Three of the seronegative horses, all from Palestine, converted to positive when resampled (8.5%). The results indicate that domestic animals in Palestine were infected with WNV in the past, and the seroconversion indicates that WNV was circulating in Palestine in the summer of 2014. Control measures to prevent human infection should be implemented in Palestine. Anti WNV antibodies in domestic animals suggest that those species can be used as

  2. Seroprevalence screening for the West Nile virus in Malaysia's Orang Asli population.

    Science.gov (United States)

    Marlina, Suria; Radzi, Siti Fatimah Muhd; Lani, Rafidah; Sieng, Khor Chee; Rahim, Nurul Farhana Abdul; Hassan, Habibi; Li-Yen, Chang; AbuBakar, Sazaly; Zandi, Keivan

    2014-12-17

    West Nile virus (WNV) infection is an emerging zoonotic disease caused by an RNA virus of the genus Flavivirus. WNV is preserved in the environment through cyclic transmission, with mosquitoes, particularly Culex species, serving as a vector, birds as an amplifying host and humans and other mammals as dead-end hosts. To date, no studies have been carried out to determine the prevalence of the WNV antibody in Malaysia. The aim of this study was to screen for the seroprevalence of the WNV in Malaysia's Orang Asli population. Serum samples of 742 Orang Asli were collected in seven states in peninsular Malaysia. The samples were assessed to determine the seroprevalence of WNV immunoglobulin (Ig)G with the WNV IgG enzyme-linked immunosorbent assay (ELISA) method. For each individual, we documented the demographic factors. Anti-dengue and anti-tick-borne encephalitis virus IgG ELISA were also performed to rule out a cross reaction. All statistical analyses were performed using the GraphPad Prism 6 (GraphPad Software, Inc.); p values of less than 0.05 were considered significant. The serosurvey included 298 men (40.16%) and 444 women (59.84%) of Malaysia's Orang Asli. Anti-WNV IgG was found in 9 of the 742 samples (1.21%). The seroprevalence was 0.67% (2 of 298) in men and 1.58% (7 of 444) in women. The presence of anti-WNV IgG was found not to be associated with gender but, however, did correlate with age. The peak seroprevalence was found to be 2.06% (2 of 97) in individuals between 30 to 42 years of age. No previous studies have examined the seroprevalence of the WNV antibody in the human population in Malaysia, and no clinical reports of infections have been made. Screening for the WNV seroprevalence is very significant because of many risk factors contribute to the presence of WNV in Malaysia, such as the abundance of Culex mosquitoes as the main vector and a high degree of biodiversity, including migratory birds that serve as a reservoir to the virus.

  3. Seroprevalence of West Nile Virus in feral horses on Sheldon National Wildlife Refuge, Nevada, United States

    Science.gov (United States)

    Franson, J. Christian; Hofmeister, Erik K.; Collins, Gail H.; Dusek, Robert J.

    2011-01-01

    We screened 1,397 feral horses (Equus caballus) on Sheldon National Wildlife Refuge, Nevada, United States, for IgM and IgG against flavivirus during 2004–2006, 2008, and 2009. Positive serum samples were tested for neutralizing antibodies to West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). One animal was positive for antibody against WNV in 2004, but all others tested in 2004–2006 were negative. In 2008 and 2009, we found evidence of increasing seropositive horses with age, whereas seroprevalence of WNV decreased from 19% in 2008 to 7.2% in 2009. No horses were positive for antibody against SLEV. Being unvaccinated, feral horses can be useful for WNV surveillance.

  4. West Nile virus ecology in a tropical ecosystem in Guatemala.

    Science.gov (United States)

    Morales-Betoulle, Maria E; Komar, Nicholas; Panella, Nicholas A; Alvarez, Danilo; López, María R; Betoulle, Jean-Luc; Sosa, Silvia M; Müller, María L; Kilpatrick, A Marm; Lanciotti, Robert S; Johnson, Barbara W; Powers, Ann M; Cordón-Rosales, Celia

    2013-01-01

    West Nile virus ecology has yet to be rigorously investigated in the Caribbean Basin. We identified a transmission focus in Puerto Barrios, Guatemala, and established systematic monitoring of avian abundance and infection, seroconversions in domestic poultry, and viral infections in mosquitoes. West Nile virus transmission was detected annually between May and October from 2005 to 2008. High temperature and low rainfall enhanced the probability of chicken seroconversions, which occurred in both urban and rural sites. West Nile virus was isolated from Culex quinquefasciatus and to a lesser extent, from Culex mollis/Culex inflictus, but not from the most abundant Culex mosquito, Culex nigripalpus. A calculation that combined avian abundance, seroprevalence, and vertebrate reservoir competence suggested that great-tailed grackle (Quiscalus mexicanus) is the major amplifying host in this ecosystem. West Nile virus transmission reached moderate levels in sentinel chickens during 2007, but less than that observed during outbreaks of human disease attributed to West Nile virus in the United States.

  5. West Nile Virus Seroprevalence in the Greek Population in 2013: A Nationwide Cross-Sectional Survey

    Science.gov (United States)

    Hadjichristodoulou, Christos; Pournaras, Spyros; Mavrouli, Maria; Marka, Andriani; Tserkezou, Persefoni; Baka, Agoritsa; Billinis, Charalambos; Katsioulis, Antonios; Psaroulaki, Anna; Papa, Anna; Papadopoulos, Nikos; Mamuris, Zissis; Tsakris, Athanasios; Kremastinou, Jenny

    2015-01-01

    Cases of West Nile Virus (WNV) disease were recorded for three consecutive years in Greece following the year 2010 outbreak. A cross-sectional serologic survey was conducted to estimate the WNV seroprevalence and assess the ratio of infection to neuroinvasive disease. A stratified left-over sampling methodology was used including age and residence strata. A total of 3,962 serum samples was collected and tested for WNV Immunoglobulin G (IgG) antibodies by Enzyme–Linked Immunosorbent Assay (ELISA). All positive samples were further tested by Plaque Reduction Neutralization Test (PRNT) and WNV Immunoglobulin M (IgM) antibodies. WNV IgG antibodies were detected in 82 samples and 61 were also positive in PRNT representing a weighted seroprevalence of 2.1% (95% C.I.: 1.7–2.6) and 1.5% (95% C.I.: 1.2–2.0), respectively. Multivariable analysis showed that seroprevalence was associated with age and residence. The overall ratio of neuroinvasive disease to infected persons was estimated at 1:376 (95% C.I.: 1:421–1:338), while the elderly people had the highest ratio. This nationwide study provided valuable data regarding the epidemiology of WNV in Greece based on the fact that elderly people have higher risk of being both infected and having severe disease. PMID:26605539

  6. Indigenous West Nile virus infections in horses in Albania.

    Science.gov (United States)

    Berxholi, K; Ziegler, U; Rexhepi, A; Schmidt, K; Mertens, M; Korro, K; Cuko, A; Angenvoort, J; Groschup, M H

    2013-11-01

    Serum samples collected from 167 equines of 12 districts in Albania were tested for West Nile virus-specific antibodies by enzyme-linked immunosorbent assay and virus neutralization assay, using WNV lineage 1 and 2. In addition, 95 bird serum samples from Albania and 29 horse samples from Kosovo were tested in ELISA. An overall seroprevalence rate of 22% was found in horses from Albania, whereas no specific antibodies were found in the equine samples from Kosovo and the bird samples. This is the first report indicating WNV infections in animals in Albania, and the first reported seroprevalence study conducted for Kosovo. These results provide evidence for widespread infections of WNV in Albania. © 2013 Blackwell Verlag GmbH.

  7. What's West Nile Virus?

    Science.gov (United States)

    ... for Educators Search English Español What's West Nile Virus? KidsHealth / For Kids / What's West Nile Virus? Print en español ¿Qué es el Virus del Nilo Occidental? What exactly is the West ...

  8. The seroprevalence of West Nile Virus in Israel: A nationwide cross sectional study.

    Directory of Open Access Journals (Sweden)

    Ravit Bassal

    Full Text Available West Nile Virus (WNV is endemic in Israel, affecting yearly 40-160 individuals. Israel is located on a central migratory path between Africa and Eurasia and most West Nile Fever (WNF cases reported in recent years were among residents of the coastal plain. The aim of the study was to evaluate the seroprevalence of WNV among the Israeli population and to assess correlates for WNV infection. A cross-sectional nationwide serologic survey was conducted using 3,145 serum samples collected by the national Israeli serum bank during 2011-2014, representing all age and population groups in Israel. Prevalence rates of WNV IgG antibodies were determined. Logistic regressions models were applied to assess the associations between demographic characteristics and WNV seropositivity. 350 samples were positive to WNV (11.1%; 95%CI: 10.0-12.3%. In the multivariable analysis, there was a significant association between seropositivity and the Arab population group vs. Jews and others (OR = 1.86, 95%CI: 1.37-2.52, the time lived in Israel [50-59 years vs. 0-9 years; OR = 10.80 (95%CI: 1.03-113.46 and ≥60 years vs. 0-9 years; OR = 14.00 (1.32-148.31] residence area] Coastal Plain, Inland Plain (Shfela and Great Rift Valley vs. Upper Galilee; OR = 2.24 (95%CI: 1.37-3.65, OR = 2.18 (95%CI: 1.18-4.03, OR = 1.90 (95%CI: 1.10-3.30, respectively [and rural vs. urban settlement (OR = 1.65, 95%CI: 1.26-2.16. People, who reside in the Coastal Plain, Inland Plain and Great Rift Valley, should be aware of the risk of contracting WNV and reduce exposure to mosquito bites, using insect repellents, and wearing protective clothing. The Ministry of Environmental Protection should be active in reducing the mosquito population by eliminating sources of standing water, a breeding ground for mosquitoes.

  9. West Nile virus infection in horses, Indian ocean.

    Science.gov (United States)

    Cardinale, E; Bernard, C; Lecollinet, S; Rakotoharinome, V M; Ravaomanana, J; Roger, M; Olive, M M; Meenowa, D; Jaumally, M R; Melanie, J; Héraud, J M; Zientara, S; Cêtre-Sossah, C

    2017-08-01

    The circulation of West Nile virus (WNV) in horses was investigated in the Southwest Indian ocean. In 2010, blood samples were collected from a total of 303 horses originating from Madagascar, Mauritius, Reunion and the Seychelles and tested for WNV-specific antibodies. An overall seroprevalence of 27.39% was detected in the Indian Ocean with the highest WNV antibody prevalence of 46.22% (95% CI: [37.4-55.2%]) in Madagascar. The age and origin of the horses were found to be associated with the WNV infection risk. This paper presents the first seroprevalence study investigating WN fever in horses in the Southwest Indian Ocean area and indicates a potential risk of infection for humans and animals. In order to gain a better understanding of WN transmission cycles, WNV surveillance needs to be implemented in each of the countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Wild Birds in Romania Are More Exposed to West Nile Virus Than to Newcastle Disease Virus.

    Science.gov (United States)

    Paştiu, Anamaria Ioana; Pap, Péter László; Vágási, Csongor István; Niculae, Mihaela; Páll, Emőke; Domşa, Cristian; Brudaşcă, Florinel Ghe; Spînu, Marina

    2016-03-01

    The aim of this study was to evaluate the seroprevalence of West Nile virus (WNV) and Newcastle disease virus (NDV) in wild and domestic birds from Romania. During 2011-2014, 159 plasma samples from wild birds assigned to 11 orders, 27 families, and 61 species and from 21 domestic birds (Gallus gallus domesticus, Anas platyrhynchos domesticus) were collected. The sera were assayed by two commercial competitive enzyme-linked immunosorbent assay (cELISA) kits for antibodies against WNV and NDV. We found a high prevalence of WNV antibodies in both domestic (19.1%) and wild (32.1%) birds captured after the human epidemic in 2010. Moreover, the presence of anti-NDV antibodies among wild birds from Romania (5.4%) was confirmed serologically for the first time, as far as we are aware. Our findings provide evidence that wild birds, especially resident ones are involved in local West Nile and Newcastle disease enzootic and epizootic cycles. These may allow virus maintenance and spread and also enhance the chance of new outbreaks.

  11. West Nile virus: North American experience

    Science.gov (United States)

    Hofmeister, Erik K.

    2011-01-01

    West Nile virus, a mosquito-vectored flavivirus of the Japanese encephalitis serogroup, was first detected in North America following an epizootic in the New York City area in 1999. In the intervening 11 years since the arrival of the virus in North America, it has crossed the contiguous USA, entered the Canadian provinces bordering the USA, and has been reported in the Caribbean islands, Mexico, Central America and, more recently, South America. West Nile virus has been reported in over 300 species of birds in the USA and has caused the deaths of thousands of birds, local population declines of some avian species, the clinical illness and deaths of thousands of domestic horses, and the clinical disease in over 30 000 Americans and the deaths of over 1000. Prior to the emergence of West Nile virus in North America, St. Louis encephalitis virus and Dengue virus were the only other known mosquito-transmitted flaviviruses in North America capable of causing human disease. This review will discuss the North American experience with mosquito-borne flavivirus prior to the arrival of West Nile virus, the entry and spread of West Nile virus in North America, effects on wild bird populations, genetic changes in the virus, and the current state of West Nile virus transmission.

  12. West Nile Virus and Usutu Virus Monitoring of Wild Birds in Germany

    Science.gov (United States)

    Michel, Friederike; Fast, Christine; Reuschel, Maximilian; Müller, Kerstin; Urbaniak, Sylvia; Brandes, Florian; Schwehn, Rebekka; Groschup, Martin H.; Ziegler, Ute

    2018-01-01

    By systematically setting up a unique nation-wide wild bird surveillance network, we monitored migratory and resident birds for zoonotic arthropod-borne virus infections, such as the flaviviruses West Nile virus (WNV) and Usutu virus (USUV). More than 1900 wild bird blood samples, from 20 orders and 136 different bird species, were collected between 2014 and 2016. Samples were investigated by WNV and USUV-specific real-time polymerase chain reactions as well as by differentiating virus neutralization tests. Dead bird surveillance data, obtained from organ investigations in 2016, were also included. WNV-specific RNA was not detected, whereas four wild bird blood samples tested positive for USUV-specific RNA. Additionally, 73 USUV-positive birds were detected in the 2016 dead bird surveillance. WNV neutralizing antibodies were predominantly found in long-distance, partial and short-distance migrants, while USUV neutralizing antibodies were mainly detected in resident wild bird species, preferentially with low seroprevalences. To date, WNV-specific RNA has neither been detected in wild birds, nor in mosquitoes, thus, we conclude that WNV is not yet present in Germany. Continued wild bird and mosquito monitoring studies are essential to detect the incursion of zoonotic viruses and to allow risk assessments for zoonotic pathogens. PMID:29361762

  13. High Prevalence of West Nile Virus in Domestic Birds and Detection in 2 New Mosquito Species in Madagascar.

    Science.gov (United States)

    Maquart, Marianne; Boyer, Sébastien; Rakotoharinome, Vincent Michel; Ravaomanana, Julie; Tantely, Michael Luciano; Heraud, Jean-Michel; Cardinale, Eric

    2016-01-01

    West Nile virus is an arthropod-borne zoonosis transmitted by a large number of mosquito species, and birds play a key role as reservoir of the virus. Its distribution is largely widespread over Africa, Asia, the Americas and Europe. Since 1978, it has frequently been reported in Madagascar. Studies described a high seroprevalence level of the virus in humans in different areas of the island and a human fatal case of WNV infection was reported in 2011. Despite these reports, the epidemiology of WNV in Madagascar, in particular, viral circulation remains unclear. To explore the transmission of WNV in two rural human populations of Madagascar, we investigated local mosquitoes and poultry for evidence of current infections, and determined seroprevalence of candidate sentinel species among the local poultry. These 2 areas are close to lakes where domestic birds, migratory wild birds and humans coexist. Serological analysis revealed WNV antibodies in domestic birds (duck, chicken, goose, turkey and guinea fowl) sampled in both districts (Antsalova 29.4% and Mitsinjo 16.7%). West Nile virus nucleic acid was detected in one chicken and in 8 pools of mosquitoes including 2 mosquito species (Aedeomyia madagascarica and Anopheles pauliani) that have not been previously described as candidate vectors for WNV. Molecular analysis of WNV isolates showed that all viruses detected were part of the lineage 2 that is mainly distributed in Africa, and were most closely matched by the previous Malagasy strains isolated in 1988. Our study showed that WNV circulates in Madagascar amongst domestic birds and mosquitoes, and highlights the utility of poultry as a surveillance tool to detect WNV transmission in a peri-domestic setting.

  14. A Fatal Neuroinvasive West Nile Virus Infection in a Traveler Returning from Madagascar: Clinical, Epidemiological and Veterinary Investigations

    Science.gov (United States)

    Larrieu, Sophie; Cardinale, Eric; Ocquidant, Philippe; Roger, Matthieu; Lepec, Richard; Delatte, Hélène; Camuset, Guillaume; Desprès, Philippe; Brottet, Elise; Charlin, Cyril; Michault, Alain

    2013-01-01

    A 58-year-old woman living in Reunion Island and returning from Madagascar was hospitalized for neuroinvasive encephalitis and died 1 month later. West Nile virus (WNV) infection was biologically confirmed by detection of immunoglobulin M (IgM) reactive with WNV antigens in both cerebrospinal fluid and serum, and weak neutralizing activity was also detected. A veterinary survey performed in her traveling area showed a seroprevalence of WNV of 28.7% (95% confidence interval [CI] = 21.1–36.3) in adult poultry, confirming an active circulation of the virus. Development of a severe form could be related to a weak antibody response, because the patient presented low IgM and IgG titers. This case report underlines the constant risk of emergence of West Nile in Indian Ocean territories, including Reunion Island where competent vectors are widely present during the whole year. PMID:23751400

  15. Monitoring of West Nile virus, Usutu virus and Meaban virus in waterfowl used as decoys and wild raptors in southern Spain.

    Science.gov (United States)

    Jurado-Tarifa, E; Napp, S; Lecollinet, S; Arenas, A; Beck, C; Cerdà-Cuéllar, M; Fernández-Morente, M; García-Bocanegra, I

    2016-12-01

    In the last decade, the number of emerging flaviviruses described worldwide has increased considerably, with wild birds acting as the main reservoir hosts of these viruses. We carried out an epidemiological survey to determine the seroprevalence of antigenically related flaviviruses, particularly West Nile virus (WNV), Usutu virus (USUV) and Meaban virus (MBV), in waterfowl used as decoys and wild raptors in Andalusia (southern Spain), the region considered to have the highest risk of flaviviruses circulation in Spain. The overall flaviviruses seroprevalence according to bELISA was 13.0% in both in decoys (n=1052) and wild raptors (n=123). Specific antibodies against WNV, USUV and MBV were confirmed by micro virus neutralization tests in 12, 38 and 4 of the seropositive decoys, respectively. This is the first study on WNV and USUV infections in decoys and the first report of MBV infections in waterfowl and raptors. Moreover we report the first description of WNV infections in short-toed snake eagle (Circaetus gallicus) and Montagu's harrier (Circus pygargus). The seropositivity obtained indicates widespread but not homogeneous distribution of WNV and USUV in Andalusia. The results also confirm endemic circulation of WNV, USUV and MBV in both decoys and wild raptors in southern Spain. Our results highlight the need to implement surveillance and control programs not only for WNV but also for other related flaviviruses. Further research is needed to determine the eco-epidemiological role that waterfowl and wild raptors play in the transmission of emerging flaviviruses, especially in decoys, given their close interactions with humans. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Seroprevalence of feline leukemia virus and feline immunodeficiency virus infection among cats in Canada.

    Science.gov (United States)

    Little, Susan; Sears, William; Lachtara, Jessica; Bienzle, Dorothee

    2009-06-01

    The purposes of this study were to determine the seroprevalence of feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infection among cats in Canada and to identify risk factors for seropositivity. Signalment, lifestyle factors, and test results for FeLV antigen and FIV antibody were analyzed for 11 144 cats from the 10 Canadian provinces. Seroprevalence for FIV antibody was 4.3% and seroprevalence for FeLV antigen was 3.4%. Fifty-eight cats (0.5%) were seropositive for both viruses. Seroprevalence varied geographically. Factors such as age, gender, health status, and lifestyle were significantly associated with risk of FeLV and FIV seropositivity. The results suggest that cats in Canada are at risk of retrovirus infection and support current recommendations that the retrovirus status of all cats should be known.

  17. Seasonal abundance and molecular identification of West Nile virus ...

    African Journals Online (AJOL)

    Seasonal abundance and molecular identification of West Nile virus vectors, Culex pipens and Culex ... Background: West Nile virus (WNV) infection, is an arbovirus infection with high morbidity and mortality, the vector respon- sible for both human ... Major diseases transmitted are known as Arboviral dis- eases because ...

  18. West Nile virus infection and diplopia: a case report and review of literature

    Directory of Open Access Journals (Sweden)

    Dahal U

    2013-05-01

    Full Text Available Udip Dahal,1 Neville Mobarakai,1 Dikshya Sharma,2 Bandana Pathak11Department of Medicine, Staten Island University Hospital, Staten Island, New York, NY, USA; 2Department of Medicine, Nepalgunj Medical College, Banke, NepalAbstract: West Nile virus is a neurotropic virus transmitted to humans via an infected mosquito bite. The increase in the incidences and fatalities of West Nile virus disease has made West Nile virus an important pathogen. Here we describe a case of a 65-year-old man with fever and diplopia presenting to the emergency department during a fall season and who was later diagnosed with West Nile virus infection. Diplopia is an uncommon manifestation of West Nile virus and recognition of the different modes of presentation, especially the uncommon ones like diplopia, will aid in the diagnosis of this emerging infectious disease.Keywords: West Nile virus, diplopia, ocular manifestations, infectious disease, Flaviviridae

  19. Phylogenetic analysis of West Nile virus, Nuevo Leon State, Mexico.

    Science.gov (United States)

    Blitvich, Bradley J; Fernández-Salas, Ildefonso; Contreras-Cordero, Juan F; Loroño-Pino, María A; Marlenee, Nicole L; Díaz, Francisco J; González-Rojas, José I; Obregón-Martínez, Nelson; Chiu-García, Jorge A; Black, William C; Beaty, Barry J

    2004-07-01

    West Nile virus RNA was detected in brain tissue from a horse that died in June 2003 in Nuevo Leon State, Mexico. Nucleotide sequencing and phylogenetic analysis of the premembrane and envelope genes showed that the virus was most closely related to West Nile virus isolates collected in Texas in 2002.

  20. West Nile virus meningitis in a patient with human immunodeficiency virus type 1 infection

    Directory of Open Access Journals (Sweden)

    D. Pilalas

    2017-09-01

    Full Text Available The emergence of West Nile virus lineage 2 in central Macedonia, Greece, in 2010 resulted in large outbreaks for 5 consecutive years. We report a case of viral meningitis in an individual infected with human immunodeficiency virus type 1, which preceded the recognition of the outbreak and was confirmed retrospectively as West Nile virus neuroinvasive disease.

  1. Vaccines in Development against West Nile Virus

    Directory of Open Access Journals (Sweden)

    Frederic Tangy

    2013-09-01

    Full Text Available West Nile encephalitis emerged in 1999 in the United States, then rapidly spread through the North American continent causing severe disease in human and horses. Since then, outbreaks appeared in Europe, and in 2012, the United States experienced a new severe outbreak reporting a total of 5,387 cases of West Nile virus (WNV disease in humans, including 243 deaths. So far, no human vaccine is available to control new WNV outbreaks and to avoid worldwide spreading. In this review, we discuss the state-of-the-art of West Nile vaccine development and the potential of a novel safe and effective approach based on recombinant live attenuated measles virus (MV vaccine. MV vaccine is a live attenuated negative-stranded RNA virus proven as one of the safest, most stable and effective human vaccines. We previously described a vector derived from the Schwarz MV vaccine strain that stably expresses antigens from emerging arboviruses, such as dengue, West Nile or chikungunya viruses, and is strongly immunogenic in animal models, even in the presence of MV pre-existing immunity. A single administration of a recombinant MV vaccine expressing the secreted form of WNV envelope glycoprotein elicited protective immunity in mice and non-human primates as early as two weeks after immunization, indicating its potential as a human vaccine.

  2. Recent progress in West Nile virus diagnosis and vaccination

    Directory of Open Access Journals (Sweden)

    De Filette Marina

    2012-03-01

    Full Text Available Abstract West Nile virus (WNV is a positive-stranded RNA virus belonging to the Flaviviridae family, a large family with 3 main genera (flavivirus, hepacivirus and pestivirus. Among these viruses, there are several globally relevant human pathogens including the mosquito-borne dengue virus (DENV, yellow fever virus (YFV, Japanese encephalitis virus (JEV and West Nile virus (WNV, as well as tick-borne viruses such as tick-borne encephalitis virus (TBEV. Since the mid-1990s, outbreaks of WN fever and encephalitis have occurred throughout the world and WNV is now endemic in Africa, Asia, Australia, the Middle East, Europe and the Unites States. This review describes the molecular virology, epidemiology, pathogenesis, and highlights recent progress regarding diagnosis and vaccination against WNV infections.

  3. West Nile virus in overwintering mosquitoes, central Europe

    Czech Academy of Sciences Publication Activity Database

    Rudolf, I.; Betášová, L.; Blažejová, H.; Venclíková, Kristýna; Straková, P.; Šebesta, O.; Mendel, J.; Bakonyi, T.; Schaffner, F.; Nowotny, N.; Hubálek, Z.

    2017-01-01

    Roč. 10, 2 October (2017), s. 1-4, č. článku 452. ISSN 1756-3305 Institutional support: RVO:61389013 Keywords : West Nile fever * West Nile virus * Flavivirus Subject RIV: EE - Microbiology, Virology OBOR OECD: Virology Impact factor: 3.080, year: 2016

  4. West Nile Virus: What You Need to Know Now - August 2012

    Centers for Disease Control (CDC) Podcasts

    2012-08-21

    This podcast lists the states where most of the 2012 West Nile viruses have been reported and explains how people can protect themselves from West Nile virus.  Created: 8/21/2012 by .   Date Released: 8/21/2012.

  5. Sero-prevalence of Human Immunodeficiency Virus and hepatitis ...

    African Journals Online (AJOL)

    Sero-prevalence of Human Immunodeficiency Virus and hepatitis viruses and their correlation with CD4 T-cell lymphocyte counts in pregnant women in the Buea Health District of Cameroon. Rebecca Enow Tanjong, Pride Teyim, Henry Lucien Kamga, Edwin Suh Neba, Theresia Nkuo-Akenji ...

  6. Sero-prevalence of Human Immunodeficiency Virus (HIV) and ...

    African Journals Online (AJOL)

    Three hundred and seven (307) healthy blood donors aged 18 – 55 years were used to determine the sero-prevalence of Human Immunodeficiency Virus (HIV) and Hepatitis B virus (HBV) in Yola, Nigeria. The association between donors' age, occupation and marital status and the prevalence of the infections among blood ...

  7. Seroprevalence of Hepatitis A Virus, Hepatitis E Virus, and Helicobacter pylori in Rural Communities of the Bolivian Chaco, 2013.

    Science.gov (United States)

    Campolmi, Irene; Spinicci, Michele; Mayaregua, David Rojo; Barahona, Herlan Gamboa; Mantella, Antonia; Lara, Yunni; Roselli, Mimmo; Strohmeyer, Marianne; Corti, Giampaolo; Tolari, Francesco; Pinckert, Joaquín Monasterio; Dalton, Harry R; Bartoloni, Alessandro

    2018-05-01

    In the Bolivian Chaco, south-east of Bolivia, studies conducted over the past three decades reported hepatitis A virus (HAV) and Helicobacter pylori seroprevalences above 90% and 60%, respectively. Hepatitis E virus (HEV) prevalence was previously found to be 6-7% but is probably an underestimate because of the poor sensitivity of the assays used. In November 2013, we conducted a cross-sectional study of 263 healthy volunteers from two rural communities of the Bolivian Chaco, aiming to reassess HAV, HEV, and H. pylori seroprevalence 10-20 years following the previous surveys. Hepatitis A virus seroprevalence was 95%, with universal exposure after the first decade of life; HEV seroprevalence was considerably higher (31-35%) than that previously reported; H. pylori seroprevalence was 59%, with an age-dependent distribution. The high prevalence of these infections suggests that major efforts are still needed to reduce fecal-oral transmission and to improve human health in the Bolivian Chaco.

  8. West Nile Virus Neuroinvasive Disease

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2009-07-01

    Full Text Available Epidemiological features of West Nile Virus (WNV disease among children (<18 years of age reported to the Centers for Disease Control and Prevention from 1999 through 2007 were analyzed and compared with those of adult WNV neuroinvasive disease (WNND, in a study at CDC&P, Fort Collins, CO.

  9. A Review of Vaccine Approaches for West Nile Virus

    Directory of Open Access Journals (Sweden)

    Konstantin G. Kousoulas

    2013-09-01

    Full Text Available The West Nile virus (WNC first appeared in North America in 1999. The North American lineages of WNV were characterized by the presence of neuroinvasive and neurovirulent strains causing disease and death in humans, birds and horses. The 2012 WNV season in the United States saw a massive spike in the number of neuroinvasive cases and deaths similar to what was seen in the 2002–2003 season, according to the West Nile virus disease cases and deaths reported to the CDC by year and clinical presentation, 1999–2012, by ArboNET (Arboviral Diseases Branch, Centers for Disease Control and Prevention. In addition, the establishment and recent spread of lineage II WNV virus strains into Western Europe and the presence of neurovirulent and neuroinvasive strains among them is a cause of major concern. This review discusses the advances in the development of vaccines and biologicals to combat human and veterinary West Nile disease.

  10. First molecular analysis of West Nile virus during the 2013 outbreak in Croatia.

    Science.gov (United States)

    Kurolt, Ivan C; Krajinović, Vladimir; Topić, Antea; Kuzman, Ilija; Baršić, Bruno; Markotić, Alemka

    2014-08-30

    This is the second subsequent year of West Nile neuroinvasive disease (WNND) outbreak in Croatia. Between July and October 2013, 22 patients presented with symptoms of WNND: all with meningitis and 18 additionally with encephalitis. In contrast to 2012, where six autochthonous infections were confirmed in eastern Croatia, the majority of this year's cases occurred in and around the city of Zagreb, where no West Nile virus infections have been observed before. Viral RNA was recovered from two patients and phylogenetic analyses revealed West Nile virus lineage 2. This represents the first molecular characterization and phylogenetic analysis of the circulating West Nile virus strain in Croatia. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. NNDSS - Table II. West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile virus disease - 2016. In this Table, provisional* cases of selected† notifiable diseases (≥1,000 cases reported during the preceding...

  12. Seroprevalences of varicella-zoster virus, herpes simplex virus and cytomegalovirus in a cross-sectional study in Mexico.

    Science.gov (United States)

    Conde-Glez, Carlos; Lazcano-Ponce, Eduardo; Rojas, Rosalba; DeAntonio, Rodrigo; Romano-Mazzotti, Luis; Cervantes, Yolanda; Ortega-Barria, Eduardo

    2013-10-17

    We estimated the seroprevalences of varicella-zoster virus (VZV), herpes simplex virus (HSV) and cytomegalovirus (CMV) in this cross-sectional database study. Serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1-70 years between January and October 2010. Serological assays for the determination of antibodies against VZV, HSV and CMV were performed. The overall seroprevalences of VZV, HSV-1, HSV-2 and CMV were 85.8%, 80.9%, 9.9% and 89.2%, respectively. Seroprevalences of VZV, HSV-1 and CMV were comparable between males and females. For HSV-2, although the seroprevalence rate was higher in females when compared to males, this difference in seroprevalence was not statistically significant. Seroprevalence rates for VZV, HSV-1, HSV-2 and CMV increased with age (p-value<.0001). Differences in seroprevalence rate for VZV by socioeconomic status (SES) were significant (p-value<0001). Results of the serological analyses reported high VZV seroprevalence, indicating high transmission in the Mexican population with children and adolescents at risk of acquiring VZV. Global HSV-1 seroprevalence was high, especially in adults. HSV-1 and HSV-2 seroprevalences were consistently higher in women than men, particularly for HSV-2. CMV seroprevalence was higher in Mexico when compared to developed countries. Seroepidemiological data on VZV supports the fact that varicella vaccination may serve as an alternative effective solution to reduce transmission in the Mexican population. For CMV and HSV, since no vaccines are available, activities to reduce transmission are important to reduce the risk of complications and therefore need to be considered. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. NNDSS - Table II. West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile virus disease - 2017. In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  14. NNDSS - Table II. West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. West Nile virus disease - 2015.In this Table, provisional cases of selected notifiable diseases (≥1,000 cases reported during the preceding year),...

  15. Analysis of YouTube as a source of information for West Nile Virus infection.

    Science.gov (United States)

    Dubey, Divyanshu; Amritphale, Amod; Sawhney, Anshudha; Dubey, Devashish; Srivastav, Nupur

    2014-12-01

    A major outbreak of West Nile Virus was seen last year in different parts of the United States. Adequate dissemination of correct information about the disease would have helped decrease its spread and the associated panic in the general population. In this study, we looked into the use of YouTube as a resource for providing information about West Nile Virus infection. This study aims to identify and evaluate YouTube as resource for providing information on West Nile Virus infection to the general public. YouTube was searched on November 25, 2012, using the keywords West Nile Virus epidemic, West Nile Virus infection, and West Nile Virus prevention for videos uploaded in the past 6 months containing relevant information about the disease. The videos were classified as useful, misleading, or as news updates based on the type of information contained. Total viewership, number of days since upload, total duration of videos, and source of upload were noted. A total of 106 videos with information on West Nile Virus infection were included in the study, with 79.24% having useful information about the disease. Among the useful videos, 51/84 (60.71%) had information on disease prevention, and 29/84 (34.52%) contained information on news and research updates. The majority of these videos were uploaded by individuals (54.6%) or news agencies (41.8 %). Healthcare agencies contributed only 3.4 % of the total videos. Even though the useful videos represented 72% of all videos, there was significantly higher total viewership and viewership per day for the non-useful videos (PYouTube may be a significant resource for dissemination of information on public health issues like West Nile virus infection and should be targeted by healthcare agencies for this use. The major drawback of this medium is lack of verification by authorized healthcare professionals before these videos are made available for viewing by the community. Hence, a strict caution should be exercised in obtaining

  16. West Nile virus in overwintering mosquitoes, central Europe

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Betášová, Lenka; Blažejová, Hana; Venclíková, Kristýna; Straková, Petra; Šebesta, Oldřich; Mendel, Jan; Bakonyi, T.; Schaffner, F.; Nowotny, N.; Hubálek, Zdeněk

    2017-01-01

    Roč. 10, č. 452 (2017), č. článku 452. ISSN 1756-3305 R&D Projects: GA ČR(CZ) GA16-20054S EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : West Nile fever * West Nile virus * Flavivirus * Hibernation * Overwintering * Culex pipiens * Anopheles maculipennis * Culiseta annulata * Czech Republic Subject RIV: EE - Microbiology, Virology OBOR OECD: Parasitology Impact factor: 3.080, year: 2016

  17. Alexander the Great and West Nile virus encephalitis.

    Science.gov (United States)

    Marr, John S; Calisher, Charles H

    2003-12-01

    Alexander the Great died in Babylon in 323 BC. His death at age 32 followed a 2-week febrile illness. Speculated causes of death have included poisoning; assassination, and a number of infectious diseases. One incident, mentioned by Plutarch but not considered by previous investigators, may shed light on the cause of Alexander's death. The incident, which occurred as he entered Babylon, involved a flock of ravens exhibiting unusual behavior and subsequently dying at his feet. The inexplicable behavior of ravens is reminiscent of avian illness and death weeks before the first human cases of West Nile virus infection were identified in the United States. We posit that Alexander may have died of West Nile virus encephalitis.

  18. 78 FR 16505 - Prospective Grant of Exclusive License: Chimeric West Nile/Dengue Viruses

    Science.gov (United States)

    2013-03-15

    ... Grant of Exclusive License: Chimeric West Nile/Dengue Viruses AGENCY: Centers for Disease Control and.... Provisional Application 61/049,342, filed 4/30/2008, entitled ``Engineered, Chimeric West Nile/Dengue Viruses;'' PCT Application PCT/US2009/041824, filed 4/27/2009, entitled ``Engineered, Chimeric WN/Flavivirus as...

  19. Seroprevalence of feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) in shelter cats on the island of Newfoundland, Canada.

    Science.gov (United States)

    Munro, Hannah J; Berghuis, Lesley; Lang, Andrew S; Rogers, Laura; Whitney, Hugh

    2014-04-01

    Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence.

  20. Purification and crystallization of dengue and West Nile virus NS2B–NS3 complexes

    Energy Technology Data Exchange (ETDEWEB)

    D’Arcy, Allan, E-mail: allan.darcy@novartis.com; Chaillet, Maxime; Schiering, Nikolaus; Villard, Frederic [Novartis Institutes of Biomedical Research, Protease Platform, Klybeckstrasse 144, CH 4002 Basel (Switzerland); Lim, Siew Pheng [Novartis Institutes of Tropical Diseases (Singapore); Lefeuvre, Peggy [Novartis Institutes of Biomedical Research, Protease Platform, Klybeckstrasse 144, CH 4002 Basel (Switzerland); Erbel, Paul [Novartis Institutes of Biomedical Research, Protease Platform, Klybeckstrasse 144, CH 4002 Basel (Switzerland); Novartis Institutes of Tropical Diseases (Singapore)

    2006-02-01

    Crystals of dengue serotype 2 and West Nile virus NS2B–NS3 protease complexes have been obtained and the crystals of both diffract to useful resolution. Sample homogeneity was essential for obtaining X-ray-quality crystals of the dengue protease. Controlled proteolysis produced a crystallizable fragment of the apo West Nile virus NS2B–NS3 and crystals were also obtained in the presence of a peptidic inhibitor. Both dengue and West Nile virus infections are an increasing risk to humans, not only in tropical and subtropical areas, but also in North America and parts of Europe. These viral infections are generally transmitted by mosquitoes, but may also be tick-borne. Infection usually results in mild flu-like symptoms, but can also cause encephalitis and fatalities. Approximately 2799 severe West Nile virus cases were reported this year in the United States, resulting in 102 fatalities. With this alarming increase in the number of West Nile virus infections in western countries and the fact that dengue virus already affects millions of people per year in tropical and subtropical climates, there is a real need for effective medicines. A possible therapeutic target to combat these viruses is the protease, which is essential for virus replication. In order to provide structural information to help to guide a lead identification and optimization program, crystallizations of the NS2B–NS3 protease complexes from both dengue and West Nile viruses have been initiated. Crystals that diffract to high resolution, suitable for three-dimensional structure determinations, have been obtained.

  1. Purification and crystallization of dengue and West Nile virus NS2B–NS3 complexes

    International Nuclear Information System (INIS)

    D’Arcy, Allan; Chaillet, Maxime; Schiering, Nikolaus; Villard, Frederic; Lim, Siew Pheng; Lefeuvre, Peggy; Erbel, Paul

    2006-01-01

    Crystals of dengue serotype 2 and West Nile virus NS2B–NS3 protease complexes have been obtained and the crystals of both diffract to useful resolution. Sample homogeneity was essential for obtaining X-ray-quality crystals of the dengue protease. Controlled proteolysis produced a crystallizable fragment of the apo West Nile virus NS2B–NS3 and crystals were also obtained in the presence of a peptidic inhibitor. Both dengue and West Nile virus infections are an increasing risk to humans, not only in tropical and subtropical areas, but also in North America and parts of Europe. These viral infections are generally transmitted by mosquitoes, but may also be tick-borne. Infection usually results in mild flu-like symptoms, but can also cause encephalitis and fatalities. Approximately 2799 severe West Nile virus cases were reported this year in the United States, resulting in 102 fatalities. With this alarming increase in the number of West Nile virus infections in western countries and the fact that dengue virus already affects millions of people per year in tropical and subtropical climates, there is a real need for effective medicines. A possible therapeutic target to combat these viruses is the protease, which is essential for virus replication. In order to provide structural information to help to guide a lead identification and optimization program, crystallizations of the NS2B–NS3 protease complexes from both dengue and West Nile viruses have been initiated. Crystals that diffract to high resolution, suitable for three-dimensional structure determinations, have been obtained

  2. West Nile virus: Immunity and pathogenesis

    NARCIS (Netherlands)

    S.M. Lim (Stephanie); P. Koraka (Penelope); A.D.M.E. Osterhaus (Albert); B.E.E. Martina (Byron)

    2011-01-01

    textabstractWest Nile virus (WNV) is a neurotropic, arthropod-borne flavivirus that is maintained in an enzootic cycle between mosquitoes and birds, but can also infect and cause disease in horses and humans. WNV is endemic in parts of Africa, Europe, the Middle East, and Asia, and since 1999 has

  3. Hepatitis A Virus and Hepatitis E Virus Seroprevalence Among Blood Donors in Tehran, Iran.

    Science.gov (United States)

    Hesamizadeh, Khashayar; Sharafi, Heidar; Keyvani, Hossein; Alavian, Seyed Moayed; Najafi-Tireh Shabankareh, Azar; Sharifi Olyaie, Roghiyeh; Keshvari, Maryam

    2016-01-01

    Hepatitis A virus (HAV) and Hepatitis E virus (HEV) are both transmitted by the fecal-oral route and are known as the leading causes of acute viral hepatitis in the world, especially in developing countries. There is a lack of updated data on HAV and HEV seroprevalence in Iran. The aim of this study was to determine the seroprevalence of HAV and HEV among a group of blood donors in Tehran, Iran. A cross-sectional study was performed from July 2014 to December 2014, on a total of 559 blood donors referred to the Tehran blood transfusion center. The serum samples were tested for antibodies to HAV and HEV, using the enzyme-linked immunosorbent assay. In the present study, 536 (95.9%) cases were male and 23 (4.1%) female with mean age of 38 years. Out of 559 blood donors, 107 (19.1%) were first-time donors, 163 (29.2%) lapsed donors and 289 (51.7%) regular donors. Anti-HAV was found in 395 (70.7%) and anti-HEV in 45 (8.1%) of the blood donors. The HAV and HEV seroprevalence increased by age. There was no significant difference between genders in terms of anti-HAV and anti-HEV status. The HAV and HEV seroprevalence was significantly related to the level of education, where the donors with higher level of education had lower rate of HAV and HEV seroprevalence. The HAV and HEV seroprevalence was significantly higher in regular and lapsed donors than in first-time donors. The present study showed that both HAV and HEV infections are still endemic in Iran.

  4. Crystallization and preliminary X-ray diffraction analysis of West Nile virus

    International Nuclear Information System (INIS)

    Kaufmann, Bärbel; Plevka, Pavel; Kuhn, Richard J.; Rossmann, Michael G.

    2010-01-01

    Crystals of infectious West Nile virus were obtained and diffracted at best to about 25 Å resolution. Preliminary analysis of the diffraction pattern suggested tight hexagonal packing of the intact virus. West Nile virus, a human pathogen, is closely related to other medically important flaviviruses of global impact such as dengue virus. The infectious virus was purified from cell culture using polyethylene glycol (PEG) precipitation and density-gradient centrifugation. Thin amorphously shaped crystals of the lipid-enveloped virus were grown in quartz capillaries equilibrated by vapor diffusion. Crystal diffraction extended at best to a resolution of about 25 Å using synchrotron radiation. A preliminary analysis of the diffraction images indicated that the crystals had unit-cell parameters a ≃ b ≃ 480 Å, γ = 120°, suggesting a tight hexagonal packing of one virus particle per unit cell

  5. Seroprevalence of yellow fever virus in selected health facilities in Western Kenya from 2010 to 2012.

    Science.gov (United States)

    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.

  6. Zika virus epidemiology in Bolivia: A seroprevalence study in volunteer blood donors.

    Science.gov (United States)

    Saba Villarroel, Paola Mariela; Nurtop, Elif; Pastorino, Boris; Roca, Yelin; Drexler, Jan Felix; Gallian, Pierre; Jaenisch, Thomas; Leparc-Goffart, Isabelle; Priet, Stéphane; Ninove, Laetitia; de Lamballerie, Xavier

    2018-03-01

    Zika virus (ZIKV), was widely reported in Latin America and has been associated with neuropathologies, as microcephaly, but only few seroprevalence studies have been published to date. Our objective was to determine the seroprevalence amongst Bolivian blood donors and estimate the future potential circulation of the virus. A ZIKV seroprevalence study was conducted between December 2016 and April 2017 in 814 asymptomatic Bolivian volunteer blood donors residing in various eco-environments corresponding to contrasting entomological activities. It was based on detection of IgG to ZIKV using NS1 ELISA screening, followed by a seroneutralisation test in case of positive or equivocal ELISA result. Analysis revealed that ZIKV circulation occurred in tropical areas (Beni: 39%; Santa Cruz de la Sierra: 21.5%) but not in highlands (~0% in Cochabamba, La Paz, Tarija). It was modulated by Aedes aegypti activity and the virus spread was not limited by previous immunity to dengue. Cases were geo-localised in a wide range of urban areas in Santa Cruz and Trinidad. No differences in seroprevalence related to gender or age-groups could be identified. It is concluded that ZIKV has been intensely circulating in the Beni region and has still a significant potential for propagating in the area of Santa Cruz.

  7. Seroprevalence of anti-hepatitis E virus antibodies in domestic pigs in Mexico.

    Science.gov (United States)

    García-Hernández, Montserrat Elemi; Cruz-Rivera, Mayra; Sánchez-Betancourt, José Iván; Rico-Chávez, Oscar; Vergara-Castañeda, Arely; Trujillo, María E; Sarmiento-Silva, Rosa Elena

    2017-09-21

    Hepatitis E virus (HEV) infection is one of the most common causes of acute liver diseases in humans worldwide. In developing countries, HEV is commonly associated with waterborne outbreaks. Conversely, in industrialized countries, HEV infection is often associated with travel to endemic regions or ingestion of contaminated animal products. Limited information on both, human and animal HEV infection in Mexico is available. As a consequence, the distribution of the virus in the country is largely unknown. Here, we assessed the seroprevalence of HEV among swine in different geographical regions in Mexico. Seroprevalence of anti-HEV antibodies in swine herds in Mexico was evaluated in a representative sample including 945 pig serum specimens from different regions of the country using a commercial enzyme-linked immunosorbent assay (ELISA). The overall prevalence of anti-HEV antibodies in swine was 59.4%. The northern region of Mexico exhibited the highest seroprevalence in the country (86.6%), while the central and southern regions in Mexico showed lower seroprevalence, 42.7% and 51.5%, respectively. In Mexico, HEV seroprevalence in swine is high. Importantly, northern Mexico showed the highest seroprevalence in the country. Thus, further studies are required to identify the risk factors contributing to HEV transmission among pigs in the country. Assessment of HEV human infection in the context of viral transmission in swine is required to better understand the epidemiology of hepatitis E in Mexico.

  8. Co-circulation of Usutu virus and West Nile virus in a reed bed ecosystem

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Bakonyi, T.; Šebesta, Oldřich; Mendel, Jan; Peško, Juraj; Betášová, Lenka; Blažejová, Hana; Venclíková, Kristýna; Straková, Petra; Nowotny, N.; Hubálek, Zdeněk

    2015-01-01

    Roč. 8, č. 520 (2015), s. 520 ISSN 1756-3305 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : Culex modestus * Usutu virus * West Nile virus * Flavivirus * Arbovirus * Surveillance * Mosquitoes Subject RIV: EE - Microbiology, Virology Impact factor: 3.234, year: 2015

  9. A review of feline leukemia virus and feline immunodeficiency virus seroprevalence in cats in Canada.

    Science.gov (United States)

    Little, Susan

    2011-10-15

    Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are common and important infectious diseases of cats in Canada. Prevalence data are necessary to define prophylactic, management, and therapeutic measures for stray, feral and owned cats. Recently, comprehensive data on the seroprevalence of retrovirus infections of cats in Canada have become available and are reviewed. Further investigation into geographic variations in retrovirus seroprevalence within Canada is warranted, and may provide information to improve recommendations for testing and prevention. As well, more information is needed on FIV subtypes in Canada to improve diagnostics and vaccines, as well as to provide information on disease outcomes. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. A recombinant influenza a virus expressing domain III of west nile virus induces protective immune responses against influenza and west nile virus

    NARCIS (Netherlands)

    B.E.E. Martina (Byron); P. van den Doel (Petra); P. Koraka (Penelope); G. van Amerongen (Geert); G. Spohn (Gunther); B.L. Haagmans (Bart); L.B.V. Provacia (Lisette); A.D.M.E. Osterhaus (Albert); G.F. Rimmelzwaan (Guus)

    2011-01-01

    textabstractWest Nile virus (WNV) continues to circulate in the USA and forms a threat to the rest of the Western hemisphere. Since methods for the treatment of WNV infections are not available, there is a need for the development of safe and effective vaccines. Here, we describe the construction of

  11. Why We Need West Nile Virus Testing

    Centers for Disease Control (CDC) Podcasts

    2016-09-27

    Dr. Rodrigo Hasbun, a professor of infectious diseases at McGovern Medical School at UT Health, discusses the need for West Nile virus testing in Texas.  Created: 9/27/2016 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 9/27/2016.

  12. Migratory birds and West Nile virus

    Czech Academy of Sciences Publication Activity Database

    Rappole, J. H.; Hubálek, Zdeněk

    2003-01-01

    Roč. 94, s1 (2003), s. 47-58 ISSN 1364-5072. [Conference of Society for Applied Microbiology (U.K.) "Pathogens in the Environment and Changing Ecosystems". Nottingham, 08.07.2002-11.07.2002] Institutional research plan: CEZ:AV0Z6093917 Keywords : West Nile virus * bird migration Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.743, year: 2003

  13. Seroprevalence of hiv and hepatitis viruses in directed blood donors ...

    African Journals Online (AJOL)

    Aims: To determine the seroprevalence of HIV and Hepatitis B viruses in directed blood donors in Nguru and also to see if there is co-infection of these viruses in this category of donor population. Method: This is a prospective study carried out at the blood bank of the Federal Medical Centre Nguru, Yobe State between ...

  14. SEROPREVALENCE OF HUMAN HERPES VIRUS 8 (HHV8 ...

    African Journals Online (AJOL)

    Praise

    SEROPREVALENCE OF HUMAN HERPES VIRUS 8 (HHV8) INFECTION. AMONG COMMERCIAL SEX WORKERS IN JOS. Zakari1, H., Nimzing2, L., Agabi1, Y. A., Amagam3, P. and Dashen,1 M. M.. 1Department of Microbiology, Faculty of Natural Sciences, University o f Jos, Nigeria. 2Department of Medical Microbiology, ...

  15. The Buzz-z-z on West Nile Virus

    Centers for Disease Control (CDC) Podcasts

    2012-01-12

    In this podcast for kids, the Kidtastics talk about West Nile Virus and how to protect yourself from it.  Created: 1/12/2012 by Centers for Disease Control and Prevention (CDC).   Date Released: 1/12/2012.

  16. West Nile virus equine serosurvey in the Czech and Slovak Republics

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Ludvíková, E.; Jahn, P.; Treml, F.; Rudolf, Ivo; Svobodová, Petra; Šikutová, Silvie; Betášová, Lenka; Bíreš, J.; Mojžíš, M.; Tinák, M.; Boldižár, M.; Citsoňová, G.; Staššíková, Z.

    2013-01-01

    Roč. 13, č. 10 (2013), s. 733-738 ISSN 1530-3667 Institutional support: RVO:68081766 Keywords : Flavivirus * Mosquito-borne virus * West Nile virus * Neutralizing antibodies * Horses Subject RIV: EE - Microbiology, Virology Impact factor: 2.531, year: 2013

  17. Interventions Against West Nile Virus, Rift Valley Fever Virus, and Crimean-Congo Hemorrhagic Fever Virus: Where Are We?

    NARCIS (Netherlands)

    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

  18. Seroprevalence of Hepatitis C Virus in People Exposed to ...

    African Journals Online (AJOL)

    This study was therefore undertaken to determine the seroprevalence of hepatitis C virus (HCV) infection in people who had been exposed to traditional surgical practices in Edo State, Nigeria. Sera from the subjects were tested for HCV antibodies using Clinotech Diagnostic test device supplied by Clinotech Diagnostic and ...

  19. West Nile Virus Encephalitis in a Barbary Macaque (Macaca sylvanus)

    Science.gov (United States)

    Barker, Ian K.; Crawshaw, Graham J.; Bertelsen, Mads F.; Drebot, Michael A.; Andonova, Maya

    2004-01-01

    An aged Barbary ape (Macaca sylvanus) at the Toronto Zoo became infected with naturally acquired West Nile virus (WNV) encephalitis that caused neurologic signs, which, associated with other medical problems, led to euthanasia. The diagnosis was based on immunohistochemical assay of brain lesions, reverse transcriptase–polymerase chain reaction, and virus isolation. PMID:15200866

  20. Serologic evidence of West Nile virus and Usutu virus infections in Eurasian coots in the Netherlands

    NARCIS (Netherlands)

    Lim, S.M.; Geervliet, M.; Verhagen, J.H.; Müskens, G.J.D.M.; Majoor, F.A.; Osterhaus, Albert D.M.E.; Martina, Byron E.

    2018-01-01

    West Nile virus (WNV) and Usutu virus (USUV) are arboviruses that are maintained in enzootic transmission cycles between mosquitoes and birds and are occasionally transmitted to mammals. As arboviruses are currently expanding their geographic range and emerging in often unpredictable locations,

  1. NNDSS - Table II. Varicella to West Nile virus disease

    Data.gov (United States)

    U.S. Department of Health & Human Services — NNDSS - Table II. Varicella to West Nile virus disease - 2014.In this Table, all conditions with a 5-year average annual national total of more than or equals 1,000...

  2. Seroprevalence of Hepatitis C Virus (HCV) antibodies in pregnant ...

    African Journals Online (AJOL)

    Background: Hepatitis C virus (HCV) infection is a major public health concern. The aim of this study was to ascertain the seroprevalence and risk factors of HCV antibodies among pregnant women in Anyigba, Kogi State North Central Nigeria. Materials and methods:Blood samples (5mls) were collected from one hundred ...

  3. Modelling West Nile virus transmission risk in Europe

    NARCIS (Netherlands)

    Vogels, Chantal B.F.; Hartemink, Nienke; Koenraadt, Constantianus J.M.

    2017-01-01

    West Nile virus (WNV) is a mosquito-borne flavivirus which has caused repeated outbreaks in humans in southern and central Europe, but thus far not in northern Europe. The main mosquito vector for WNV, Culex pipiens, consists of two behaviourally distinct biotypes, pipiens and molestus, which can

  4. [Birds, mosquitoes and West Nile virus: little risk of West Nile fever in the Netherlands].

    Science.gov (United States)

    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.

  5. Seroprevalence of Hepatitis A virus infection in non-human primates in Assam, India

    Directory of Open Access Journals (Sweden)

    B.G. Nath

    2013-08-01

    Full Text Available The present study investigated 37 serum samples of non-human primates in Assam State Zoo and the Department of Forest and Environment, Govt. of Assam for seroprevalence of hepatitis A virus infection during the period from December, 2007 to November, 2009. Four serum samples were also collected from animal keepers of the zoo to investigate transmission of the disease to the attendants working with these primates. Competitive ELISA was performed using hepatitis A virus ELISA kit (Wanti Hep. AV to detect hepatitis A virus antibody in serum samples. Ten (27.21% of the non-human primate samples and three (75% human samples had detectable anti-hepatitis A virus antibodies. Living status of the non-human primates (Free living was a high potential risk for hepatitis A virus infection. Seroprevalence of hepatitis A virus infection had significant difference between free living non-human primates and captive non-human primates (P less than 0.05. No significant difference (p=0.86 was seen between male and female non-human primates

  6. Increased Pathogenicity of West Nile Virus (WNV by Glycosylation of Envelope Protein and Seroprevalence of WNV in Wild Birds in Far Eastern Russia

    Directory of Open Access Journals (Sweden)

    Hiroaki Kariwa

    2013-12-01

    Full Text Available In this review, we discuss the possibility that the glycosylation of West Nile (WN virus E-protein may be associated with enhanced pathogenicity and higher replication of WN virus. The results indicate that E-protein glycosylation allows the virus to multiply in a heat-stable manner and therefore, has a critical role in enhanced viremic levels and virulence of WN virus in young-chick infection model. The effect of the glycosylation of the E protein on the pathogenicity of WN virus in young chicks was further investigated. The results indicate that glycosylation of the WN virus E protein is important for viral multiplication in peripheral organs and that it is associated with the strong pathogenicity of WN virus in birds. The micro-focus reduction neutralization test (FRNT in which a large number of serum samples can be handled at once with a small volume (15 μL of serum was useful for differential diagnosis between Japanese encephalitis and WN virus infections in infected chicks. Serological investigation was performed among wild birds in the Far Eastern region of Russia using the FRNT. Antibodies specific to WN virus were detected in 21 samples of resident and migratory birds out of 145 wild bird samples in the region.

  7. Seroprevalence of hepatitis E virus among blood donors in Qatar (2013-2016).

    Science.gov (United States)

    Nasrallah, Gheyath K; Al Absi, Enas S; Ghandour, Rula; Ali, Nadima H; Taleb, Sara; Hedaya, Laila; Ali, Fatima; Huwaidy, Mariam; Husseini, Abdullatif

    2017-07-01

    Hepatitis E virus (HEV) is an RNA virus transmitted mainly through zoonotic transmission or fecal-oral route. More than 80% of Qatar's population are expatriates, including many coming from hyperendemic countries; thus, it is important to estimate the seroprevalence and to compare between different nationalities. The results can be useful in alerting blood banks to the importance of HEV screening. Samples from 5854 blood donations provided by Hamad Medical Corporation were tested in the period between June 2013 to June 2016. Samples were tested for the presence of anti-HEV immunoglobulin (Ig)G and IgM antibodies and viral RNA using real-time polymerase chain reaction (PCR). Descriptive statistics, bivariate analysis, and multivariate logistic regression were used. Anti-HEV seroprevalence was 20.7%. A total of 1198 and 38 donations tested positive for IgG and IgM antibodies, respectively. Of the IgM-positive donations four tested positive by PCR. A significant association was detected between HEV seroprevalence with age and nationality. The seroprevalence of anti-HEV was high in Qatar. Since HEV IgM and RNA were detected, this suggests the possibility of HEV transmission by transfusion. Blood banks in Qatar and the region should consider screening for HEV, especially when transfusion is intended to pregnant women or immunocompromised patients. © 2017 AABB.

  8. Seroprevalence of Hepatitis E Virus in Four Species of Parrots in China

    Directory of Open Access Journals (Sweden)

    Xiao-Xuan Zhang, Nian-Zhang Zhang, Dong-Hui Zhou, Wei-Peng Tian, Ying-Tian Xu and Xing-Quan Zhu

    2014-01-01

    Full Text Available In this study, antibodies against avian Hepatitis E Virus (avian HEV were detected in 6.43% of examined serum samples (n=311 from budgerigars (Melopsittacus undulatus, lovebirds (Agapornis sp., cockatiel (Nymphicus hollandicus and Alexandrine parakeets (Psittacula eupatria by indirect ELISA. Seroprevalence of avian HEV infection in different parrot species varied from 0 to 7.92%. Statistical analysis of the origins of parrots demonstrated that parrots from Weifang city had a higher avian HEV seropositivity (7.84% compared with parrots from Beijing city (5.06%. The seroprevalence in parrots of different age groups varied from 4 to 7.62%. The avian HEV seroprevalence in parrots examined in spring and summer was 7.19 and 5.81%, respectively. This is the first report of avian HEV seroprevalence in four species of parrots in China, which will provide base-line data for the control of HEV infection in parrots in China.

  9. Sero-prevalence of immunodeficiency virus, hepatitis B and C and ...

    African Journals Online (AJOL)

    Objectives: This study aimed to determine the sero-prevalence of transfusion transmitted infections (TTIs), namely immunodeficiency virus, hepatitis B and C and syphilis among blood donors. Setting: The study was carried in the blood bank at ElObeid Teaching Hospital. Material and methods: The study included 260 blood ...

  10. Drought and immunity determine the intensity of West Nile virus epidemics and climate change impacts.

    Science.gov (United States)

    Paull, Sara H; Horton, Daniel E; Ashfaq, Moetasim; Rastogi, Deeksha; Kramer, Laura D; Diffenbaugh, Noah S; Kilpatrick, A Marm

    2017-02-08

    The effect of global climate change on infectious disease remains hotly debated because multiple extrinsic and intrinsic drivers interact to influence transmission dynamics in nonlinear ways. The dominant drivers of widespread pathogens, like West Nile virus, can be challenging to identify due to regional variability in vector and host ecology, with past studies producing disparate findings. Here, we used analyses at national and state scales to examine a suite of climatic and intrinsic drivers of continental-scale West Nile virus epidemics, including an empirically derived mechanistic relationship between temperature and transmission potential that accounts for spatial variability in vectors. We found that drought was the primary climatic driver of increased West Nile virus epidemics, rather than within-season or winter temperatures, or precipitation independently. Local-scale data from one region suggested drought increased epidemics via changes in mosquito infection prevalence rather than mosquito abundance. In addition, human acquired immunity following regional epidemics limited subsequent transmission in many states. We show that over the next 30 years, increased drought severity from climate change could triple West Nile virus cases, but only in regions with low human immunity. These results illustrate how changes in drought severity can alter the transmission dynamics of vector-borne diseases. © 2017 The Author(s).

  11. Occurrence of West Nile Virus Antibodies in Wild Birds, Horses, and Humans in Poland

    Directory of Open Access Journals (Sweden)

    Jowita Samanta Niczyporuk

    2015-01-01

    Full Text Available Serum samples of 474 wild birds, 378 horses, and 42 humans with meningitis and lymphocytic meningitis were collected between 2010 and 2014 from different areas of Poland. West Nile virus (WNV antibodies were detected using competition enzyme linked immunosorbent assays: ELISA-1 ID Screen West Nile Competition, IDvet, ELISA-2 ID Screen West Nile IgM Capture, and ELISA-3 Ingezim West Nile Compac. The antibodies were found in 63 (13.29% out of 474 wild bird serum samples and in one (0.26% out of 378 horse serum samples. Fourteen (33.33% out of 42 sera from patients were positive against WNV antigen and one serum was doubtful. Positive samples obtained in birds were next retested with virus microneutralisation test to confirm positive results and cross-reactions with other antigens of the Japanese encephalitis complex. We suspect that positive serological results in humans, birds, and horses indicate that WNV can be somehow closely related with the ecosystem in Poland.

  12. A GIS-driven integrated real-time surveillance pilot system for national West Nile virus dead bird surveillance in Canada

    Directory of Open Access Journals (Sweden)

    Aramini Jeff

    2006-04-01

    Full Text Available Abstract Background An extensive West Nile virus surveillance program of dead birds, mosquitoes, horses, and human infection has been launched as a result of West Nile virus first being reported in Canada in 2001. Some desktop and web GIS have been applied to West Nile virus dead bird surveillance. There have been urgent needs for a comprehensive GIS services and real-time surveillance. Results A pilot system was developed to integrate real-time surveillance, real-time GIS, and Open GIS technology in order to enhance West Nile virus dead bird surveillance in Canada. Driven and linked by the newly developed real-time web GIS technology, this integrated real-time surveillance system includes conventional real-time web-based surveillance components, integrated real-time GIS components, and integrated Open GIS components. The pilot system identified the major GIS functions and capacities that may be important to public health surveillance. The six web GIS clients provide a wide range of GIS tools for public health surveillance. The pilot system has been serving Canadian national West Nile virus dead bird surveillance since 2005 and is adaptable to serve other disease surveillance. Conclusion This pilot system has streamlined, enriched and enhanced national West Nile virus dead bird surveillance in Canada, improved productivity, and reduced operation cost. Its real-time GIS technology, static map technology, WMS integration, and its integration with non-GIS real-time surveillance system made this pilot system unique in surveillance and public health GIS.

  13. High seroprevalence of antibodies to avian influenza viruses among wild waterfowl in Alaska: implications for surveillance

    Science.gov (United States)

    Wilson, Heather M.; Hall, Jeffery S.; Flint, Paul L.; Franson, J. Christian; Ely, Craig R.; Schmutz, Joel A.; Samuel, Michael D.

    2013-01-01

    We examined seroprevalence (presence of detectable antibodies in serum) for avian influenza viruses (AIV) among 4,485 birds, from 11 species of wild waterfowl in Alaska (1998–2010), sampled during breeding/molting periods. Seroprevalence varied among species (highest in eiders (Somateria and Polysticta species), and emperor geese (Chen canagica)), ages (adults higher than juveniles), across geographic locations (highest in the Arctic and Alaska Peninsula) and among years in tundra swans (Cygnus columbianus). All seroprevalence rates in excess of 60% were found in marine-dependent species. Seroprevalence was much higher than AIV infection based on rRT-PCR or virus isolation alone. Because pre-existing AIV antibodies can infer some protection against highly pathogenic AIV (HPAI H5N1), our results imply that some wild waterfowl in Alaska could be protected from lethal HPAIV infections. Seroprevalence should be considered in deciphering patterns of exposure, differential infection, and rates of AIV transmission. Our results suggest surveillance programs include species and populations with high AIV seroprevalences, in addition to those with high infection rates. Serologic testing, including examination of serotype-specific antibodies throughout the annual cycle, would help to better assess spatial and temporal patterns of AIV transmission and overall disease dynamics.

  14. Vector competence of the stable fly (Diptera: Muscidae)for West Nile virus.

    Science.gov (United States)

    Stable flies, which are notorious pests of cattle and other livestock, were suspected of transmitting West Nile virus (WNV) among American white pelicans at the Medicine Lake Wildlife Refuge in northeastern Montana in 2006-2007. However the ability of stable flies to transmit the virus was unknown. ...

  15. West Nile virus infection in cats : ABCD guidelines on prevention and management

    NARCIS (Netherlands)

    Egberink, Herman; Addie, Diane D; Boucraut-Baralon, Corine; Frymus, Tadeusz; Gruffydd-Jones, Tim; Hartmann, Katrin; Horzinek, Marian C; Hosie, Margaret J; Marsilio, Fulvio; Lloret, Albert; Lutz, Hans; Pennisi, Maria Grazia; Radford, Alan D; Thiry, Etienne; Truyen, Uwe; Möstl, Karin

    OVERVIEW: West Nile virus (WNV) is a zoonotic mosquito-borne virus with a broad host range that infects mainly birds and mosquitos, but also mammals (including humans), reptiles, amphibians and ticks. It is maintained in a bird-mosquito-bird transmission cycle. The most important vectors are

  16. Immunogenicity and protective efficacy of recombinant Modified Vaccinia virus Ankara candidate vaccines delivering West Nile virus envelope antigens

    NARCIS (Netherlands)

    Volz, Asisa; Lim, Stephanie; Kaserer, Martina; Pijlman, Gorben P.

    2016-01-01

    West Nile virus (WNV) cycles between insects and wild birds, and is transmitted via mosquito vectors to horses and humans, potentially causing severe neuroinvasive disease. Modified Vaccinia virus Ankara (MVA) is an advanced viral vector for developing new recombinant vaccines against infectious

  17. Reported Neuroinvasive Cases of West Nile Virus by State, 2002-2014

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map shows the average annual incidence of neuroinvasive West Nile virus disease in each state, which is calculated as the average number of new cases per...

  18. Hepatitis C Virus Seroprevalence in Blood Donors at the University ...

    African Journals Online (AJOL)

    Background/Aim: Hepatitis C Virus (HCV) is a leading cause of chronic liver disease worldwide. In developing countries, blood transfusion is still a major route of its transmission. The aim of this study was to determine the seroprevalence of HCV infection among blood donors and to determine some of the risk factors for the ...

  19. Seroprevalence of hepatitis E virus in domestic pigs and wild boars in Switzerland.

    Science.gov (United States)

    Burri, C; Vial, F; Ryser-Degiorgis, M-P; Schwermer, H; Darling, K; Reist, M; Wu, N; Beerli, O; Schöning, J; Cavassini, M; Waldvogel, A

    2014-12-01

    Hepatitis E is considered an emerging human viral disease in industrialized countries. Studies from Switzerland report a human seroprevalence of hepatitis E virus (HEV) of 2.6-21%, a range lower than in adjacent European countries. The aim of this study was to determine whether HEV seroprevalence in domestic pigs and wild boars is also lower in Switzerland and whether it is increasing and thus indicating that this zoonotic viral infection is emerging. Serum samples collected from 2,001 pigs in 2006 and 2011 and from 303 wild boars from 2008 to 2012 were analysed by ELISA for the presence of HEV-specific antibodies. Overall HEV seroprevalence was 58.1% in domestic pigs and 12.5% in wild boars. Prevalence in domestic pigs was significantly higher in 2006 than in 2011. In conclusion, HEV seroprevalence in domestic pigs and wild boars in Switzerland is comparable with the seroprevalence in other countries and not increasing. Therefore, prevalence of HEV in humans must be related to other factors than prevalence in pigs or wild boars. © 2014 Blackwell Verlag GmbH.

  20. Chronic West Nile virus infection in kea (Nestor notabilis)

    Czech Academy of Sciences Publication Activity Database

    Bakonyi, T.; Gaydon, G. K.; Schwing, R.; Vogl, W.; Häbich, A.-C.; Thaller, D.; Weissenböck, H.; Rudolf, Ivo; Hubálek, Zdeněk; Nowotny, N.

    2016-01-01

    Roč. 183, February (2016), s. 135-139 ISSN 0378-1135 EU Projects: European Commission(XE) 261504 - EDENEXT; European Commission(XE) 261391 - EUROWESTNILE Institutional support: RVO:68081766 Keywords : West Nile virus * Lineage 2 * Kea * Nestor notabilis * Psittaciformes * Persistent infection * Austria Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 2.628, year: 2016

  1. Seroprevalence of Human Immunodeficiency Virus, Hepatitis B Virus, Hepatitis C Virus, and Treponema pallidum Infections among Blood Donors on Bioko Island, Equatorial Guinea.

    Directory of Open Access Journals (Sweden)

    Dong-De Xie

    Full Text Available Regular screening of transfusion-transmissible infections (TTIs, such as human immunodeficiency virus (HIV, hepatitis B and hepatitis C virus (HBV and HCV, respectively, and Treponema pallidum, in blood donors is essential to guaranteeing clinical transfusion safety. This study aimed to determine the seroprevalence of four TTIs among blood donors on Bioko Island, Equatorial Guinea (EG.A retrospective survey of blood donors from January 2011 to April 2013 was conducted to assess the presence of HIV, HBV, HCV and T. pallidum. The medical records were analyzed to verify the seroprevalence of these TTIs among blood donations stratified by gender, age and geographical region.Of the total 2937 consecutive blood donors, 1098 (37.39% had a minimum of one TTI and 185 (6.29% harbored co-infections. The general seroprevalence of HIV, HBV, HCV and T. pallidum were 7.83%, 10.01%, 3.71% and 21.51%, respectively. The most frequent TTI co-infections were HBV-T. pallidum 60 (2.04% and HIV-T. pallidum 46 (1.57%. The seroprevalence of HIV, HBV, HCV and T. pallidum were highest among blood donors 38 to 47 years, 18 to 27 years and ≥ 48 years age, respectively (P<0.05. The seroprevalence of TTIs varied according to the population from which the blood was collected on Bioko Island.Our results firstly provide a comprehensive overview of TTIs among blood donors on Bioko Island. Strict screening of blood donors and improved hematological examinations using standard operating procedures are recommended.

  2. Evolution of hepatitis A virus seroprevalence among HIV-positive adults in Taiwan

    Science.gov (United States)

    Lin, Kuan-Yin; Cheng, Chien-Yu; Li, Chia-Wen; Yang, Chia-Jui; Tsai, Mao-Song; Tang, Hung-Jen; Lin, Te-Yu; Wang, Ning-Chi; Lee, Yi-Chien; Lin, Shih-Ping; Huang, Yu-Shan; Sun, Hsin-Yun; Zhang, Jun-Yu; Ko, Wen-Chien; Cheng, Shu-Hsing; Lee, Yuan-Ti; Hung, Chien-Ching

    2017-01-01

    Objectives The study aimed to describe the seroprevalence of hepatitis A virus (HAV) in HIV-positive adult patients in Taiwan between 2012 and 2016 and to examine the evolution of HAV seroprevalence between 2004–2007 and 2012–2016. Methods Clinical information and data of anti-HAV antibody results were collected from 2,860 antiretroviral-naïve HIV-positive Taiwanese aged 18 years or older who initiated combination antiretroviral therapy at 11 hospitals around Taiwan between 2012 and 2016 (2012–2016 cohort). A multivariate logistic regression model was applied to identify independent variables associated with HAV seropositivity. Comparisons of HAV seroprevalences and associated clinical characteristics were made between this 2012–2016 cohort and a previous cohort of 1580 HIV-positive patients in 2004–2007 (2004–2007 cohort). Results Of the 2,860 HIV-positive patients between 2012 and 2016, the overall HAV seropositivity rate was 21.2% (605/2860), which was independently associated with an older age (adjusted odds ratio [AOR], per 1-year increase, 1.13; 95% confidence interval [95% CI], 1.11–1.15) and co-infection with hepatitis B virus (AOR 1.44; 95% CI, 1.08–1.93). Residence in southern Taiwan (AOR 0.49; 95% CI, 0.34–0.72) was inversely associated with HAV seropositivity. The overall HAV seroprevalence in the 2012–2016 cohort was significantly lower than that in the 2004–2007 cohort (21.2% vs 60.9%, pa country without nationwide childhood vaccination program against HAV. PMID:29036227

  3. Clinical Manifestations and Outcomes of West Nile Virus Infection

    Directory of Open Access Journals (Sweden)

    James J. Sejvar

    2014-02-01

    Full Text Available Since the emergence of West Nile virus (WNV in North America in 1999, understanding of the clinical features, spectrum of illness and eventual functional outcomes of human illness has increased tremendously. Most human infections with WNV remain clinically silent. Among those persons developing symptomatic illness, most develop a self-limited febrile illness. More severe illness with WNV (West Nile neuroinvasive disease, WNND is manifested as meningitis, encephalitis or an acute anterior (polio myelitis. These manifestations are generally more prevalent in older persons or those with immunosuppression. In the future, a more thorough understanding of the long-term physical, cognitive and functional outcomes of persons recovering from WNV illness will be important in understanding the overall illness burden.

  4. Seroprevalence of antibodies against chikungunya virus in Singapore resident adult population.

    Science.gov (United States)

    Ang, Li Wei; Kam, Yiu Wing; Lin, Cui; Krishnan, Prabha Unny; Tay, Joanne; Ng, Lee Ching; James, Lyn; Lee, Vernon J M; Goh, Kee Tai; Ng, Lisa F P; Lin, Raymond T P

    2017-12-01

    We determined the seroprevalence of chikungunya virus (CHIKV) infection in the adult resident population in Singapore following local outbreaks of chikungunya fever (CHIKF) in 2008-2009. Our cross-sectional study involved residual sera from 3,293 adults aged 18-79 years who had participated in the National Health Survey in 2010. Sera were tested for IgG antibodies against CHIKV and dengue virus (DENV) and neutralizing antibodies against CHIKV. The prevalence of CHIKV-neutralizing antibodies among Singapore residents aged 18-79 years was 1.9% (95% confidence interval: 1.4%- 2.3%). The CHIKV seroprevalence was highest in the elderly aged 70-79 years at 11.5%, followed by those aged 30-39 years at 3.1%. Men had significantly higher CHIKV seroprevalence than women (2.5% versus 1.3%, p = 0.01). Among the three main ethnic groups, Indians had the highest seroprevalence (3.5%) compared to Chinese (1.6%) and Malays (0.7%) (p = 0.02 and p = 0.01, respectively). Multivariable logistic regression identified adults aged 30-39 years and 70-79 years, men, those of Indian ethnicity and ethnic minority groups, and residence on ground floor of public and private housing apartments as factors that were significantly associated with a higher likelihood of exposure to CHIKV. The overall prevalence of anti-DENV IgG antibodies was 56.8% (95% CI: 55.1%- 58.5%), while 1.5% (95% CI: 1.1%- 2.0%) of adults possessed both neutralizing antibodies against CHIKV and IgG antibodies against DENV. Singapore remains highly susceptible to CHIKV infection. There is a need to maintain a high degree of vigilance through disease surveillance and vector control. Findings from such serological study, when conducted on a regular periodic basis, could supplement surveillance to provide insights on CHIKV circulation in at-risk population.

  5. Molecularly engineered live-attenuated chimeric West Nile/dengue virus vaccines protect rhesus monkeys from West Nile virus

    International Nuclear Information System (INIS)

    Pletnev, Alexander G.; St Claire, Marisa; Elkins, Randy; Speicher, Jim; Murphy, Brian R.; Chanock, Robert M.

    2003-01-01

    Two molecularly engineered, live-attenuated West Nile virus (WN) vaccine candidates were highly attenuated and protective in rhesus monkeys. The vaccine candidates are chimeric viruses (designated WN/DEN4) bearing the membrane precursor and envelope protein genes of WN on a backbone of dengue 4 virus (DEN4) with or without a deletion of 30 nucleotides (Δ30) in the 3' noncoding region of DEN4. Viremia in WN/DEN4- infected monkeys was reduced 100-fold compared to that in WN- or DEN4-infected monkeys. WN/DEN4-3'Δ30 did not cause detectable viremia, indicating that it is even more attenuated for monkeys. These findings indicate that chimerization itself and the presence of the Δ30 mutation independently contribute to the attenuation phenotype for nonhuman primates. Despite their high level of attenuation in monkeys, the chimeras induced a moderate-to-high titer of neutralizing antibodies and prevented viremia in monkeys challenged with WN. The more attenuated vaccine candidate, WN/DEN4-3'Δ30, will be evaluated first in our initial clinical studies

  6. Pathogenicity of West Nile virus and response to vaccination in sandhill cranes (Grus canadensis) using a killed vaccine.

    Science.gov (United States)

    Olsen, Glenn H; Miller, Kimberli J; Docherty, Douglas E; Bochsler, Valerie S; Sileo, Louis

    2009-06-01

    West Nile virus was introduced into the United States in the vicinity of New York, New York, USA in 1999. The virus has since killed large numbers of birds nationwide, especially, but not limited to, crows (Corvus brachyrhinchos). One sandhill crane (Grus canadensis) at the Bridgeport Zoo (Bridgeport, Connecticut, USA) reportedly died from West Nile virus, so sandhill cranes and endangered whooping cranes (Grus americana), both in the wild and in captive breeding colonies at United States Geological Service (USGS) Patuxent Wildlife Research Center (Laurel, Maryland, USA) were considered at risk. A killed vaccine in sandhill cranes was evaluated by vaccinating and then challenging these cranes with live West Nile virus. No sandhill cranes inoculated with the killed vaccine developed significant titers when compared with unvaccinated controls. No sandhill cranes inoculated with the vaccine and challenged with the virus died from West Nile virus infection. In addition, no unvaccinated challenged sandhill cranes died. However, 2 days postchallenge, vaccinated cranes had significantly less viremia (P cranes. Seven days postchallenge vaccinated cranes had significantly less cloacal shedding of the virus (P cranes and significantly less weight loss (P cranes. Vaccinated sandhill cranes developed significantly higher titers 14 days postchallenge and were viremic for shorter periods of time after challenge than unvaccinated individuals. Unvaccinated challenged cranes had glial cell aggregates in both the brain and brain stem areas, and this was not observed in vaccinated challenged cranes or in vaccinated unchallenged cranes.

  7. West Nile Virus Drug Discovery

    Directory of Open Access Journals (Sweden)

    Siew Pheng Lim

    2013-12-01

    Full Text Available The outbreak of West Nile virus (WNV in 1999 in the USA, and its continued spread throughout the Americas, parts of Europe, the Middle East and Africa, underscored the need for WNV antiviral development. Here, we review the current status of WNV drug discovery. A number of approaches have been used to search for inhibitors of WNV, including viral infection-based screening, enzyme-based screening, structure-based virtual screening, structure-based rationale design, and antibody-based therapy. These efforts have yielded inhibitors of viral or cellular factors that are critical for viral replication. For small molecule inhibitors, no promising preclinical candidate has been developed; most of the inhibitors could not even be advanced to the stage of hit-to-lead optimization due to their poor drug-like properties. However, several inhibitors developed for related members of the family Flaviviridae, such as dengue virus and hepatitis C virus, exhibited cross-inhibition of WNV, suggesting the possibility to re-purpose these antivirals for WNV treatment. Most promisingly, therapeutic antibodies have shown excellent efficacy in mouse model; one of such antibodies has been advanced into clinical trial. The knowledge accumulated during the past fifteen years has provided better rationale for the ongoing WNV and other flavivirus antiviral development.

  8. Seroprevalence of hepatitis E virus among blood donors in Qatar (2013-2016)

    OpenAIRE

    Nasrallah, Gheyath K.; Al Absi, Enas S.; Ghandour, Rula; Ali, Nadima H.; Taleb, Sara; Hedaya, Laila; Ali, Fatima; Huwaidy, Mariam; Husseini, Abdullatif

    2017-01-01

    BACKGROUND Hepatitis E virus (HEV) is an RNA virus transmitted mainly through zoonotic transmission or fecal–oral route. More than 80% of Qatar's population are expatriates, including many coming from hyperendemic countries; thus, it is important to estimate the seroprevalence and to compare between different nationalities. The results can be useful in alerting blood banks to the importance of HEV screening. STUDY DESIGN AND METHODS Samples from 5854 blood donations provided by Ham...

  9. General seroprevalence of hepatitis and hepatitis B virus infections in population

    International Nuclear Information System (INIS)

    Khokar, N.; Gill, M.L.; Malik, G.J.

    2004-01-01

    Objective: To determine the prevalence of hepatitis C virus (HCV) and hepatitis B virus (HBV) infection by detection of anti-HCV and hepatitis B surface antigen (HbsAg) in general population of Pakistan. Materials and Methods: Sera of healthy adult individuals who presented for medical evaluation as a pre-employment criteria in the Gulf region were examined for presence of hepatitis B surface antigen and anti-HCV antibody. Alanine aminotransferase levels were also determined. Results: A total of 47,538 individuals were examined. Out of these, 2528 (5.31%) were positive for anti-HCV and 1221 (2.56%) individuals had positive HBsAg. Hepatitis B surface antigen and anti-HCV both were found in 92 (0.19%) individuals. Mean age of subjects, positive for HCV antibody was 44 years and 40.5 years for HBV. Ninety-four percent individuals were males and 6% were females. Alanine aminotransferase (ALT) was normal in 56% of subjects with positive HCV and 84% of individuals with HBV. Conclusion: This study which evaluated predominantly a healthy male population, showed a high seroprevalence of anti-HCV and average seroprevalence of hepatitis B virus infection. A large majority of these patients was young and had normal ALT. (author)

  10. Seroprevalence of Hepatitis A Virus Antibodies among the Patients with Chronic Hepatitis B in Turkey.

    Science.gov (United States)

    Tulek, Necla; Ozsoy, Metin; Moroglu, Cigdem; Cagla Sonmezer, Meliha; Temocin, Fatih; Tuncer Ertem, Gunay; Sebnem Erdinc, Fatma

    2015-01-01

    Hepatitis A virus (HAV) can cause significant pathology in patients with chronic hepatitis B virus (HBV), however, HAV can be prevented by vaccination. The aim of this study was to determine the implication of vaccination against HAV vaccine in patients with chronic hepatitis B. The seroprevalence of anti-HAV IgG antibodies was investigated in the patients with chronic hepatitis B. Anti-HAV IgG antibodies were detected by commercially available ELISA kit. A total of 673 patients (354 males, 319 females with age range of 17-78 years) with chronic hepatitis B were included the study. Hepatitis A virus seropositivity rate was 34% in the patients younger than 20 years, 79% in the age group of 20 to 29 years, and 100% after 35 years of age. Hepatitis A virus vaccination may be recommended for young adult patients with chronic hepatitis B in Turkey. Tulek N, Ozsoy M, Moroglu C, Sonmezer MC, Temocin F, Ertem GT, Erdinc FS. Seroprevalence of Hepatitis A Virus Antibodies among the Patients with Chronic Hepatitis B in Turkey. Euroasian J Hepato-Gastroenterol 2015;5(2):95-97.

  11. The seroprevalence and seroincidence of dengue virus infection in western Kenya.

    Science.gov (United States)

    Blaylock, Jason M; Maranich, Ashley; Bauer, Kristen; Nyakoe, Nancy; Waitumbi, John; Martinez, Luis J; Lynch, Julia

    2011-09-01

    Epidemics of dengue fever have been documented throughout the African continent over the past several decades, however little is known about the prevalence or incidence of dengue virus infection in the absence of an outbreak. No studies have analyzed the prevalence of dengue infection in western Kenya to date. This study describes the seroincidence and seroprevalence of dengue infection in western Kenya. Banked sera obtained from 354 healthy, afebrile children ages 12-47 months from Kisumu District, Kenya, were analyzed for antibodies to dengue virus using an IgG indirect ELISA. We found a seroprevalence of 1.1% (4 of 354 samples) and incidence of 8.5 seroconversions per 1000 persons per year in this study population. This appears to be similar to that previously reported in coastal regions of the country outside of known epidemic periods. Since there has never been a reported dengue epidemic in western Kenya, continued investigation and evaluation in a patient population presenting with fever is necessary to further confirm this finding. Published by Elsevier Ltd.

  12. Seroprevalence of fecal-oral transmitted hepatitis A and E virus antibodies in Burkina Faso.

    Science.gov (United States)

    Traoré, Kuan Abdoulaye; Rouamba, Hortense; Nébié, Yacouba; Sanou, Mahamadou; Traoré, Alfred S; Barro, Nicolas; Roques, Pierre

    2012-01-01

    Hepatitis A virus (HAV) and hepatitis E virus (HEV) infections occur chiefly as a result of unhygienic conditions. The purpose of this study was to assess the seroprevalence of antibodies to both viruses in central Burkina Faso in the absence of a recorded hepatitis epidemic. Serum samples from 178 blood donors (131 males and 47 females) and from 189 pregnant women were collected from November 2010 to March 2012, at blood banks and medical centers in Burkina Faso. An immunochromatography test was used to screen for Anti-HAV IgM and IgG in a subgroup of 91 blood donors and 100 pregnant women. The seroprevalence of anti-HAV IgG was 14.3% [CI95, 7.1-21.4%] for all blood donors and 23% [CI95, 14.8-31.2%] for pregnant women. Anti-HEV IgG were detected using the ELISA kits Dia.pro and Wantai and were found in 19.1% [CI95, 13.3-24.9%] of the blood donors and 11.6% [CI95, 7.1-16.2%] of the pregnant women. The seroprevalences of anti-HAV and anti-HEV IgGs did not differ significantly between men and women blood donors. Anti-HAV IgM was detected in 3.3% of the blood donors and in 2% of the pregnant women. These findings for asymptomatic individuals indicate that the HAV and HEV circulate at low but significant levels. This is the first evaluation of the acute hepatitis virus burden in Burkina Faso and the underlying epidemiologic status of the population.

  13. The outbreak of West Nile virus infection in the New York City area in 1999.

    Science.gov (United States)

    Nash, D; Mostashari, F; Fine, A; Miller, J; O'Leary, D; Murray, K; Huang, A; Rosenberg, A; Greenberg, A; Sherman, M; Wong, S; Layton, M

    2001-06-14

    In late August 1999, an unusual cluster of cases of meningoencephalitis associated with muscle weakness was reported to the New York City Department of Health. The initial epidemiologic and environmental investigations suggested an arboviral cause. Active surveillance was implemented to identify patients hospitalized with viral encephalitis and meningitis. Cerebrospinal fluid, serum, and tissue specimens from patients with suspected cases underwent serologic and viral testing for evidence of arboviral infection. Outbreak surveillance identified 59 patients who were hospitalized with West Nile virus infection in the New York City area during August and September of 1999. The median age of these patients was 71 years (range, 5 to 95). The overall attack rate of clinical West Nile virus infection was at least 6.5 cases per million population, and it increased sharply with age. Most of the patients (63 percent) had clinical signs of encephalitis; seven patients died (12 percent). Muscle weakness was documented in 27 percent of the patients and flaccid paralysis in 10 percent; in all of the latter, nerve conduction studies indicated an axonal polyneuropathy in 14 percent. An age of 75 years or older was an independent risk factor for death (relative risk adjusted for the presence or absence of diabetes mellitus, 8.5; 95 percent confidence interval, 1.2 to 59.1), as was the presence of diabetes mellitus (age-adjusted relative risk, 5.1; 95 percent confidence interval, 1.5 to 17.3). This outbreak of West Nile meningoencephalitis in the New York City metropolitan area represents the first time this virus has been detected in the Western Hemisphere. Given the subsequent rapid spread of the virus, physicians along the eastern seaboard of the United States should consider West Nile virus infection in the differential diagnosis of encephalitis and viral meningitis during the summer months, especially in older patients and in those with muscle weakness.

  14. A recombinant influenza A virus expressing domain III of West Nile virus induces protective immune responses against influenza and West Nile virus.

    Science.gov (United States)

    Martina, Byron E E; van den Doel, Petra; Koraka, Penelope; van Amerongen, Geert; Spohn, Gunther; Haagmans, Bart L; Provacia, Lisette B V; Osterhaus, Albert D M E; Rimmelzwaan, Guus F

    2011-04-26

    West Nile virus (WNV) continues to circulate in the USA and forms a threat to the rest of the Western hemisphere. Since methods for the treatment of WNV infections are not available, there is a need for the development of safe and effective vaccines. Here, we describe the construction of a recombinant influenza virus expressing domain III of the WNV glycoprotein E (Flu-NA-DIII) and its evaluation as a WNV vaccine candidate in a mouse model. FLU-NA-DIII-vaccinated mice were protected from severe body weight loss and mortality caused by WNV infection, whereas control mice succumbed to the infection. In addition, it was shown that one subcutaneous immunization with 10(5) TCID(50) Flu-NA-DIII provided 100% protection against challenge. Adoptive transfer experiments demonstrated that protection was mediated by antibodies and CD4+T cells. Furthermore, mice vaccinated with FLU-NA-DIII developed protective influenza virus-specific antibody titers. It was concluded that this vector system might be an attractive platform for the development of bivalent WNV-influenza vaccines.

  15. A recombinant influenza A virus expressing domain III of West Nile virus induces protective immune responses against influenza and West Nile virus.

    Directory of Open Access Journals (Sweden)

    Byron E E Martina

    Full Text Available West Nile virus (WNV continues to circulate in the USA and forms a threat to the rest of the Western hemisphere. Since methods for the treatment of WNV infections are not available, there is a need for the development of safe and effective vaccines. Here, we describe the construction of a recombinant influenza virus expressing domain III of the WNV glycoprotein E (Flu-NA-DIII and its evaluation as a WNV vaccine candidate in a mouse model. FLU-NA-DIII-vaccinated mice were protected from severe body weight loss and mortality caused by WNV infection, whereas control mice succumbed to the infection. In addition, it was shown that one subcutaneous immunization with 10(5 TCID(50 Flu-NA-DIII provided 100% protection against challenge. Adoptive transfer experiments demonstrated that protection was mediated by antibodies and CD4+T cells. Furthermore, mice vaccinated with FLU-NA-DIII developed protective influenza virus-specific antibody titers. It was concluded that this vector system might be an attractive platform for the development of bivalent WNV-influenza vaccines.

  16. Import of West Nile virus infection in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Lukáčová, L.; Halouzka, Jiří; Širůček, P.; Januška, J.; Přecechtělová, J.; Procházka, P.

    2006-01-01

    Roč. 21, č. 4 (2006), s. 323-324 ISSN 0393-2990 R&D Projects: GA ČR GA206/03/0726 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : West Nile virus * CNS infection * Flavivirus Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.605, year: 2006

  17. Surveillance for West Nile virus in clinic-admitted raptors, Colorado.

    Science.gov (United States)

    Nemeth, Nicole; Kratz, Gail; Edwards, Eric; Scherpelz, Judy; Bowen, Richard; Komar, Nicholas

    2007-02-01

    In 2005, 13.5% of clinic-admitted raptors in northern Colorado tested positive for West Nile virus (WNV). Clinic-admitted-raptor surveillance detected WNV activity nearly 14 weeks earlier than other surveillance systems. WNV surveillance using live raptor admissions to rehabilitation clinics may offer a novel surveillance method and should be considered along with other techniques already in use.

  18. Seroprevalence of the Hepatitis B, Hepatitis C, and Human Immunodeficiency Viruses and Treponema pallidum at the Beijing General Hospital from 2010 to 2014: A Cross-Sectional Study.

    Directory of Open Access Journals (Sweden)

    Shaoxia Xu

    Full Text Available The hepatitis B, hepatitis C, human immunodeficiency viruses and Treponema pallidum are important causes of infectious diseases concern to public health.Between 2010 and 2014, we used an automated chemiluminescence microparticle immunoassay to detect the hepatitis B, hepatitis C, and human immunodeficiency viruses as well as Treponema pallidum (the rapid plasma regain test was used in 2010-2011. Positive human immunodeficiency virus tests were confirmed via western blotting.Among 416,130 subjects, the seroprevalences for hepatitis B virus, hepatitis C virus, human immunodeficiency virus, and Treponema pallidum were 5.72%, 1.23%, 0.196%, and 0.76%, respectively. Among 671 patients with positive human immunodeficiency virus results, 392 cases were confirmed via western blotting. Hepatitis B and human immunodeficiency virus infections were more frequent in men (7.78% and 0.26%, respectively than in women (4.45% and 0.021%, respectively. The hepatitis B and C virus seroprevalences decreased from 6.21% and 1.58%, respectively, in 2010, to 5.37% and 0.988%, respectively, in 2014. The human immunodeficiency virus seroprevalence increased from 0.04% in 2010 to 0.17% in 2014, and was elevated in the Infectious Disease (2.65%, Emergency (1.71%, and Dermatology and Sexually Transmitted Diseases (1.12% departments. The specificity of the human immunodeficiency virus screening was 71.4%. The false positive rates for the Treponema pallidum screening tests increased in patients who were 60-70 years old. The co-infection rates for the hepatitis C and human immunodeficiency viruses were 0.47% in hepatitis C virus-positive patients and 7.33% in human immunodeficiency virus-positive patients.During 2010-2014, hepatitis B virus and human immunodeficiency virus infections were more frequent among men at our institution. Although the seroprevalences of hepatitis B and C viruses decreased, the seroprevalence of human immunodeficiency virus infection increased (with

  19. The seroprevalence of pandemic influenza H1N1 (2009 virus in China.

    Directory of Open Access Journals (Sweden)

    Cuiling Xu

    2011-04-01

    Full Text Available Mainland China experienced pandemic influenza H1N1 (2009 virus (pH1N1 with peak activity during November-December 2009. To understand the geographic extent, risk factors, and attack rate of pH1N1 infection in China we conducted a nationwide serological survey to determine the prevalence of antibodies to pH1N1.Stored serum samples (n = 2,379 collected during 2006-2008 were used to estimate baseline serum reactogenicity to pH1N1. In January 2010, we used a multistage-stratified random sampling method to select 50,111 subjects who met eligibility criteria and collected serum samples and administered a standardized questionnaire. Antibody response to pH1N1 was measured using haemagglutination inhibition (HI assay and the weighted seroprevalence was calculated using the Taylor series linearization method. Multivariable logistic regression analyses were used to examine risk factors for pH1N1 seropositivity. Baseline seroprevalence of pH1N1 antibody (HI titer ≥40 was 1.2%. The weighted seroprevalence of pH1N1 among the Chinese population was 21.5%(vaccinated: 62.0%; unvaccinated: 17.1%. Among unvaccinated participants, those aged 6-15 years (32.9% and 16-24 years (30.3% had higher seroprevalence compared with participants aged 25-59 years (10.7% and ≥60 years (9.9%, P<0.0001. Children in kindergarten and students had higher odds of seropositivity than children in family care (OR: 1.36 and 2.05, respectively. We estimated that 207.7 million individuals (15.9% experienced pH1N1 infection in China.The Chinese population had low pre-existing immunity to pH1N1 and experienced a relatively high attack rate in 2009 of this virus. We recommend routine control measures such as vaccination to reduce transmission and spread of seasonal and pandemic influenza viruses.

  20. Serologic survey of potential vertebrate hosts for West Nile Virus in Poland

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Wegner, E.; Halouzka, Jiří; Tryjanowski, P.; Jerzak, L.; Šikutová, Silvie; Rudolf, Ivo; Kruszewicz, A. G.; Jaworski, Z.; Włodarczyk, R.

    2008-01-01

    Roč. 21, č. 2 (2008), s. 247-254 ISSN 0882-8245 R&D Projects: GA AV ČR IAA600930611 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Source of funding: R - rámcový projekt EK Keywords : antibodies – West Nile virus – Usutu virus – Flavivirus * Poland * birds * horses Subject RIV: EE - Microbiology, Virology Impact factor: 1.949, year: 2008

  1. Low intrathecal antibody production despite high seroprevalence of Epstein-Barr virus in multiple sclerosis: a review of the literature.

    Science.gov (United States)

    Ruprecht, Klemens; Wildemann, Brigitte; Jarius, Sven

    2018-02-01

    Patients with multiple sclerosis (MS) frequently have an intrathecal production of antibodies to different common viruses, which can be detected by elevated antiviral antibody indices (AIs). There is a strong and consistent association of MS and Epstein-Barr virus (EBV) infection. To systematically compare the frequencies of intrathecal antibody production to EBV, measles virus, rubella virus, varicella zoster virus (VZV) and herpes simplex virus (HSV) in patients with MS. Review of the English and German literature on the frequencies of intrathecal immunoglobulin (Ig)G antibody production, as defined by an elevated AI, to EBV, measles virus, rubella virus, VZV and HSV in adult and pediatric patients with MS. In nine original studies identified, the frequencies of an intrathecal production of antibodies to Epstein-Barr nuclear antigen-1 (33/340, 9.7%), EBV viral capsid antigen (12/279, 4.3%) and antigens from EBV-infected cell lines (14/90, 15.6%) in adult patients with MS were clearly lower (p ≤ 0.03 for all pairwise comparisons) than the frequencies of an intrathecal production of antibodies to measles virus (612/922, 66.4%), rubella virus (521/922, 56.5%), VZV (470/922, 51%; data from 17 original studies) and HSV (78/291, 26.8%; data from 6 original studies). Though based on a lower number of original studies and patients, findings in children with MS were essentially similar. As in adults and children with MS the seroprevalence of EBV is higher than the seroprevalences of the other investigated viruses, the lower frequency of elevated EBV AIs became even more pronounced after correction of the frequencies of elevated antiviral AIs for the seroprevalences of the respective viruses. Given the very high seroprevalence of EBV in MS, the frequency of intrathecally produced antibodies to EBV in patients with MS is paradoxically low compared to that of other common viruses. These findings are compatible with the recently proposed hypothesis that in individuals

  2. West Nile Virus positive blood donation and subsequent entomological investigation, Austria, 2014

    Czech Academy of Sciences Publication Activity Database

    Kolodziejek, J.; Seidel, B.; Jungbauer, C.; Dimmel, K.; Kolodziejek, M.; Rudolf, Ivo; Hubálek, Zdeněk; Allerberger, F.; Nowotny, N.

    2015-01-01

    Roč. 10, č. 5 (2015), e0126381 E-ISSN 1932-6203 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : West Nile virus * Austria Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 3.057, year: 2015

  3. Seroprevalence of hepatitis A virus in a cross-sectional study in Mexico

    Science.gov (United States)

    Lazcano-Ponce, Eduardo; Conde-Gonzalez, Carlos; Rojas, Rosalba; DeAntonio, Rodrigo; Romano-Mazzotti, Luis; Cervantes, Yolanda; Ortega-Barria, Eduardo

    2013-01-01

    Hepatitis A virus (HAV) remains a public health concern worldwide contributing to significant morbidity in developed and developing countries. This cross-sectional database study estimated the overall HAV seroprevalence and the seroprevalence by gender, age, region and socioeconomic status in Mexico. Between January and October 2010, serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1–95 y. Subjects’ gender, age, geographical region and socioeconomic status were extracted from the survey and compiled into a subset database by the Mexican National Institute of Public Health. Anti-HAV antibodies were measured using a chemiluminescent immunoassay. A total of 3658 subjects were included in the according-to-protocol cohort. Overall, the HAV seroprevalence was 84.2%. The HAV seroprevalence rates were similar between females (86.1%) and males (82.2%). The percentage of subjects seropositive for anti-HAV antibodies was highest in adults aged ≥ 20 y (96.9%), followed by adolescents aged 10–19 y (80.1%) and lowest in children aged 1–9 y (45.0%) (p < 0.0001). Regionally, the highest HAV seroprevalence rate was observed in the South (88.8%) followed by Central and Northern Mexico and Mexico City (p = 0.02). The HAV seroprevalence was similar between subjects of high socioeconomic (90.1%) status and of low socioeconomic status (86.6%). This study confirms the intermediate HAV endemicity in Mexico. Cost-effectiveness studies are necessary to evaluate the inclusion of an effective hepatitis A vaccine from a population-based perspective in addition to continuous efforts to improve hygiene and sanitation that have a substantial impact on the disease burden. PMID:23291940

  4. Neutralizing activities of human immunoglobulin derived from donors in Japan against mosquito-borne flaviviruses, Japanese encephalitis virus, West Nile virus, and dengue virus

    Directory of Open Access Journals (Sweden)

    Yunoki M

    2016-07-01

    Full Text Available Mikihiro Yunoki,1-3 Takeshi Kurosu,2 Ritsuko Kubota Koketsu,2,4 Kazuo Takahashi,5 Yoshinobu Okuno,4 Kazuyoshi Ikuta2,4 1Research and Development Division, Japan Blood Products Organization, Tokyo, 2Department of Virology, Research Institute for Microbial Diseases, Osaka University, Osaka, 3Pathogenic Risk Evaluation, Graduate School of Veterinary Medicine, Rakuno Gakuen University, Hokkaido, 4Research and Development Division, The Research Foundation for Microbial Diseases of Osaka University, Kagawa, 5Osaka Prefectural Institute of Public Health, Osaka, Japan Abstract: Japanese encephalitis virus (JEV, West Nile virus (WNV, and dengue virus (DenV are causal agents of Japanese encephalitis, West Nile fever, and dengue fever, respectively. JEV is considered to be indigenized and widespread in Japan, whereas WNV and DenV are not indigenized in Japan. Globulin products seem to reflect the status of the donor population according to antivirus neutralization activity. However, the anti-JEV, -WNV, and -DenV neutralization activities of globulin products derived from donors in Japan have not been clarified. Furthermore, potential candidates for the development of an effective immunotherapeutic drug for encephalitis caused by JEV, WNV, or DenV have also not been identified. Therefore, the aim of this study was to determine the overall status of the donor population in Japan based on globulin products by evaluating anti-JEV, -WNV, and -DenV neutralizing activities of intravenous immunoglobulin. Overall, intravenous immunoglobulin products showed stable neutralizing activity against JEV but showed no or only weak activity against WNV or DenV. These results suggest that the epidemiological level against WNV and DenV in the donor population of Japan is still low, suggesting that these viruses are not yet indigenized. In addition, JEV vaccinations and/or infections in the donor population do not induce a cross-reactive antibody against WNV. Keywords

  5. Seroprevalence survey of H9N2 avian influenza virus in backyard chickens around the Caspian Sea in Iran

    Directory of Open Access Journals (Sweden)

    MM Hadipour

    2010-03-01

    Full Text Available Since 1998, an epidemic of avian influenza occurred in the Iranian poultry industry. The identified agent presented low pathogenicity, and was subtyped as an H9N2 avian influenza virus. Backyard chickens can play an important role in the epidemiology of H9N2 avian influenza virus infection. Close contact of backyard chickens with migratory birds, especially with aquatic birds, as well as neighboring poultry farms, may pose the risk of transmitting avian influenza virus, but little is known about the disease status of backyard poultry. A H9N2 avian influenza virus seroprevalence survey was carried out in 700 backyard chickens from villages around the Caspian Sea, Northern Iran, using the hemagglutination-inhibition (HI test. The studied backyard chickens had not been previously vaccinated and showed no clinical signs of disease. The mean antibody titers found were 6.8, 7.5, 5.9, 7.2, 5.7, 6.4, 6.2 and the seroprevalence was 76.2%, 79.5%, 68.18%, 78.27%, 65%, 72.31% and 71.4% as found in seven villages. Overall HI titer and seroprevalence against H9N2 were 6.52 and 72.98%, respectively.

  6. Emerging vector-borne diseases in dromedaries in Tunisia: West Nile, bluetongue, epizootic haemorrhagic disease and Rift Valley fever

    Directory of Open Access Journals (Sweden)

    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.

  7. Emerging vector-borne diseases in dromedaries in Tunisia: West Nile, bluetongue, epizootic haemorrhagic disease and Rift Valley fever.

    Science.gov (United States)

    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.

  8. Experimental susceptibility of Wood Ducks (Aix sponsa) for West Nile virus

    Science.gov (United States)

    Hofmeister, Erik K.; Porter, Robert E.; Franson, J. Christian

    2015-01-01

    Detection of West Nile virus (WNV) has been reported in a variety of wild ducks in the US, but little is known about the pathogenesis and outcome of exposure of the disease in these species. Previous experimental studies of WNV in ducks either have challenged a small number of ducks with WNV or have tested domesticated ducks. To determine susceptibility and immune response, we challenged 7-wk-old Wood Ducks (Aix sponsa) with a 1999 American Crow (Corvus brachyrhynchos) isolate of WNV. Wood Ducks were susceptible to infection with the virus, and, although clinical signs or mortality were not observed, microscopic lesions were noted, particularly in the heart and brain. West Nile virus viremia peaked on day 2 postinfection (pi) at 104.54 plaque-forming units (PFU) of virus/mL serum and WNV was shed orally (between 102and 102.9 PFU per swab) and cloacally. Specific anti-WNV antibody response was rapid, with anti-WNV IgM detected on day 3 pi followed on day 5 pi by anti-WNV IgG. Neutralizing antibodies were detected by plaque-reduction neutralization assay in one duck on day 4 pi, and in all sampled ducks on day 5. These results indicate that Wood Ducks are susceptible to WNV, but it is unlikely that significant WNV mortality events occur in Wood Ducks or that ducks play a significant role in transmission. However, WNV viremia was sufficient, in theory, to infect mosquitoes, and oral and cloacal shedding of the virus may increase the risk of infection to other waterbirds.

  9. Screening for West Nile virus infections of susceptible animal species in Austria

    Czech Academy of Sciences Publication Activity Database

    Weissenböck, H.; Hubálek, Zdeněk; Halouzka, Jiří; Pichlmair, A.; Maderner, A.; Fragner, K.; Kolodziejek, J.; Loupal, G.; Kölbl, S.; Nowotny, N.

    2003-01-01

    Roč. 131, c. 2 (2003), s. 1023-1027 ISSN 0950-2688 Grant - others:Hochschuljubiläumsstiftung der Stadt Wien(AT) - Institutional research plan: CEZ:AV0Z6093917 Keywords : West Nile virus Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 1.509, year: 2003

  10. Seroprevalence of Epstein-Barr virus among HIV positive patients moreover and its association with CD4 positive lymphocyte count.

    Directory of Open Access Journals (Sweden)

    Alireza Abdollahi

    2014-12-01

    Full Text Available Opportunistic infections are the leading cause of hospitalization and morbidity in human immunodeficiency virus (HIV positive patients and are the most common cause of death between them. We aimed to measure IgG antibody against EBV viral capsid antigen (EBV-VCA IgG to determine the seroprevalence of this infection in HIV-positive population. A case-control study between September 2011 and October 2012 was conducted in a teaching hospital enrolling 114 HIV-positive patients as case group and 114 healthy individuals as control with similar age and sex. Enzyme-linked immunosurbant assay (ELISA technique was used for determination of EBV-VAC IgG in obtained samples. Of 114 serum samples obtained from HIV-positive patients, 103 (90.4% samples were found positive for EBV-VCA IgG antibody. There was no significant difference in seroprevalence of EBV VCA IgG antibody between patients received antiretroviral therapy and naive patients (91.5% vs. 87.5%, P>0.05. There was no statistically significant difference in EBV-VCA IgG seroprevalence between three groups of CD4+ in HIV positive group. In conclusion current study showed that seroprevalence of EBV in HIV-positive patients is higher than HIV-negative healthy participants; however, administration of HAART and CD4+ lymphocyte count did not reveal a significant effect in seroprevalence of EBV. Due to the significance of this virus in mortality and morbidity and causing certain malignancies in patients with AIDS, these patients are strongly recommended to be tested for this virus.

  11. West Nile virus isolated from a Virginia opossum (Didelphis virginiana) in northwestern Missouri, USA, 2012.

    Science.gov (United States)

    Bosco-Lauth, Angela; Harmon, Jessica R; Lash, R Ryan; Weiss, Sonja; Langevin, Stanley; Savage, Harry M; Godsey, Marvin S; Burkhalter, Kristen; Root, J Jeffrey; Gidlewski, Thomas; Nicholson, William L; Brault, Aaron C; Komar, Nicholas

    2014-10-01

    We describe the isolation of West Nile virus (WNV; Flaviviridae, Flavivirus) from blood of a Virginia opossum (Didelphis virginiana) collected in northwestern Missouri, USA in August 2012. Sequencing determined that the virus was related to lineage 1a WNV02 strains. We discuss the role of wildlife in WNV disease epidemiology.

  12. Sero-prevalence of Hepatitis B virus among middle to high socio ...

    African Journals Online (AJOL)

    Keywords: Hepatitis B virus, Sero-prevalence, Sierra Leone, Socio-economic. Résumé Cette étude a été faite pour la recherche d'une prédominance de HVB sur les femmes enceintes d'un niveau moyen socio-économique à un niveau supérieur en Sierra Léone. Le but a été de déterminer le nécessité et les avantages ...

  13. Factors influencing HIV seroprevalence rate among pregnant ...

    African Journals Online (AJOL)

    Human immune deficiency virus (HIV) seroprevalence among pregnant women in Calabar was studied. The aims were to establish HIV seroprevalence rate and to identify factors which influence this rate in our pregnant women. HIV seroprevalence rate of 2.7% among antenatal women in Calabar was recorded with a ...

  14. Detecting West Nile virus in owls and raptors by an antigen-capture assay.

    Science.gov (United States)

    Gancz, Ady Y; Campbell, Douglas G; Barker, Ian K; Lindsay, Robbin; Hunter, Bruce

    2004-12-01

    We evaluated a rapid antigen-capture assay (VecTest) for detection of West Nile virus in oropharyngeal and cloacal swabs, collected at necropsy from owls (N = 93) and raptors (N = 27). Sensitivity was 93.5%-95.2% for northern owl species but raptors.

  15. Detecting West Nile Virus in Owls and Raptors by an Antigen-capture Assay

    OpenAIRE

    Gancz, Ady Y.; Campbell, Douglas G.; Barker, Ian K.; Lindsay, Robbin; Hunter, Bruce

    2004-01-01

    We evaluated a rapid antigen-capture assay (VecTest) for detection of West Nile virus in oropharyngeal and cloacal swabs, collected at necropsy from owls (N = 93) and raptors (N = 27). Sensitivity was 93.5%–95.2% for northern owl species but

  16. Evaluating red-cockaded woodpeckers for exposure to West Nile Virus and blood parasites

    Science.gov (United States)

    Dusek, Robert J.; Richardson, D.; Egstad, Kristina F.; Heisey, Dennis M.

    2006-01-01

    A marked decline in the Picoides borealis (Red-cockaded Woodpecker [RCW]) population at Noxubee National Wildlife Refuge, MS, was observed in 2002. Demographic changes - including absence of hatch-year birds, decreases in size of known groups, and loss of known groups-were identified during annual fall surveys and are uncharacteristic of RCW populations. In 2003, a serosurvey of 28 adult RCWs was conducted to investigate the presence of West Nile virus (WNV) exposure in the population, possibly providing insight into whether WNV may have been responsible for this decline. Blood smears were also examined from these birds for blood parasites. We found no evidence of West Nile virus exposure or blood parasites in any of the RCWs sampled. Further monitoring of the RCW population and WNV activity in other species at Noxubee NWR is recommended to further evaluate the potential role of WNV and blood parasites in their decline.

  17. Importance of bird-to-bird transmission for the establishment of West Nile Virus

    NARCIS (Netherlands)

    Hartemink, N.A.; Davis, S.A.; Reiter, P.; Hubálek, Z.; Heesterbeek, J.A.P.

    2007-01-01

    West Nile virus (WNV) is principally considered to be maintained in a mosquito–bird transmission cycle. Under experimental conditions, several other transmission routes have been observed, but the significance of these additional routes in nature is unknown. Here, we derive an expression for the

  18. West Nile Virus Outbreak in Houston and Harris County, Texas, USA, 2014.

    Science.gov (United States)

    Martinez, Diana; Murray, Kristy O; Reyna, Martin; Arafat, Raouf R; Gorena, Roberto; Shah, Umair A; Debboun, Mustapha

    2017-08-01

    Since 2002, West Nile virus (WNV) has been detected every year in Houston and the surrounding Harris County, Texas. In 2014, the largest WNV outbreak to date occurred, comprising 139 cases and causing 2 deaths. Additionally, 1,286 WNV-positive mosquito pools were confirmed, the most reported in a single mosquito season.

  19. Detection of West Nile virus-specific antibodies and nucleic acid in horses and mosquitoes, respectively, in Nuevo Leon State, northern Mexico, 2006-2007.

    Science.gov (United States)

    Ibarra-Juarez, L; Eisen, L; Bolling, B G; Beaty, B J; Blitvich, B J; Sanchez-Casas, R M; Ayala-Sulca, Y O; Fernandez-Salas, I

    2012-09-01

    In the last 5 years, there has been only one reported human case of West Nile virus (WNV) disease in northern Mexico. To determine if the virus was still circulating in this region, equine and entomological surveillance for WNV was conducted in the state of Nuevo Leon in northern Mexico in 2006 and 2007. A total of 203 horses were serologically assayed for antibodies to WNV using an epitope-blocking enzyme-linked immunosorbent assay (bELISA). Seroprevalences for WNV in horses sampled in 2006 and 2007 were 26% and 45%, respectively. Mosquito collections in 2007 produced 7365 specimens representing 15 species. Culex mosquitoes were screened for WNV RNA and other genera (Mansonia, Anopheles, Aedes, Psorophora and Uranotaenia) were screened for flaviviruses using reverse-transcription (RT)-PCR. Two pools consisting of Culex spp. mosquitoes contained WNV RNA. Molecular species identification revealed that neither pool included Culex quinquefasciatus (Say) (Diptera:Culicidae) complex mosquitoes. No evidence of flaviviruses was found in the other mosquito genera examined. These data provide evidence that WNV is currently circulating in northern Mexico and that non-Cx. quinquefasciatus spp. mosquitoes may be participating in the WNV transmission cycle in this region. Published 2012. This article is a U.S. Government work and is in the public domain in the USA.

  20. Prevalence of West Nile virus in migratory birds during spring and fall migration

    Science.gov (United States)

    Dusek, Robert J.; McLean, R.G.; Kramer, L.D.; Ubico, S.R.; Dupuis, A.P.; Ebel, G.D.; Guptill, S.C.

    2009-01-01

    To investigate the role of migratory birds in the dissemination of West Nile virus (WNV), we measured the prevalence of infectious WNV and specific WNV neutralizing antibodies in birds, principally Passeriformes, during spring and fall migrations in the Atlantic and Mississippi flyways from 2001-2003. Blood samples were obtained from 13,403 birds, representing 133 species. Specific WNV neutralizing antibody was detected in 254 resident and migratory birds, representing 39 species, and was most commonly detected in northern cardinals (Cardinalis cardinalis) (9.8%, N = 762) and gray catbirds (Dumetella carolinensis) (3.2%,N = 3188). West Nile virus viremias were detected in 19 birds, including 8 gray catbirds, and only during the fall migratory period. These results provide additional evidence that migratory birds may have been a principal agent for the spread of WNV in North America and provide data on the occurrence of WNV in a variety of bird species. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

  1. Seroprevalences of feline leukemia virus and feline immunodeficiency virus infection in cats in the United States and Canada and risk factors for seropositivity.

    Science.gov (United States)

    Burling, Amie N; Levy, Julie K; Scott, H Morgan; Crandall, Michael M; Tucker, Sylvia J; Wood, Erin G; Foster, Jessie D

    2017-07-15

    OBJECTIVE To estimate seroprevalences for FeLV antigen and anti-FIV antibody and risk factors for seropositivity among cats in the United States and Canada. DESIGN Cross-sectional study. ANIMALS 62,301 cats tested at 1,396 veterinary clinics (n = 45,406) and 127 animal shelters (16,895). PROCEDURES Blood samples were tested with a point-of-care ELISA for FeLV antigen and anti-FIV antibody. Seroprevalence was estimated, and risk factors for seropositivity were evaluated with bivariate and multivariable mixed-model logistic regression analyses adjusted for within-clinic or within-shelter dependencies. RESULTS Overall, seroprevalence was 3.1% for FeLV antigen and 3.6% for anti-FIV antibody. Adult age, outdoor access, clinical disease, and being a sexually intact male were risk factors for seropositivity for each virus. Odds of seropositivity for each virus were greater for cats tested in clinics than for those tested in shelters. Of 1,611 cats with oral disease, 76 (4.7%) and 157 (9.7%) were seropositive for FeLV and FIV, respectively. Of 4,835 cats with respiratory disease, 385 (8.0%) were seropositive for FeLV and 308 (6.4%) were seropositive for FIV. Of 1,983 cats with abscesses or bite wounds, 110 (5.5%) and 247 (12.5%) were seropositive for FeLV and FIV, respectively. Overall, 2,368 of 17,041 (13.9%) unhealthy cats were seropositive for either or both viruses, compared with 1,621 of 45,260 (3.6%) healthy cats. CONCLUSIONS AND CLINICAL RELEVANCE Seroprevalences for FeLV antigen and anti-FIV antibody were similar to those reported in previous studies over the past decade. Taken together, these results indicated a need to improve compliance with existing guidelines for management of feline retroviruses.

  2. Seroprevalence of Schmallenberg virus in dairy cattle in Ethiopia.

    Science.gov (United States)

    Sibhat, Berhanu; Ayelet, Gelagay; Gebremedhin, Endrias Zewdu; Skjerve, Eystein; Asmare, Kassahun

    2018-02-01

    Schmallenberg virus (SBV) is a recently identified member of the genus Orthobunyavirus of the family Bunyaviridae. It is an arbovirus transmitted by different members of Culicoides spp of biting midges. The virus is more recognized for its effect on reproductive disorders in ruminants characterised by abortion, stillbirth and birth of congenitally defective newborns with hydranencephaly-arthrogryposis syndrome. The current study was undertaken with the objectives of exploring the presence of SBV exposure and identification of factors affecting its distribution among dairy cattle in Ethiopia. A cross-sectional study was conducted on 1379 dairy cattle sampled from 149 dairy herds in central, southern and western Ethiopia during September 2011 to May 2012. Serum samples were examined using competitive enzyme linked immunosorbent assay (cELISA). Data on hypothesised risk factors were collected from farm records where available and semi-structured questionnaire-based interview. The apparent seroprevalence of exposure to SBV was 56.6% (95% confidence interval (CI): 53.9-59.3). True prevalence adjusted for sensitivity and specificity of the cELISA kit used was 58.3% (95% CI 55.7-60.9). Among the sampled herds, 82.6% (95% CI: 75.5-88.3) had at least one seropositive animal. Seropositive cattle were found in all of the 15 conurbations studied. Adult dairy cows [odds ratio (OR)=1.6] were more commonly affected than young heifers. Dairy cattle kept in commercial (OR=1.6) and breeding farms (OR=3.5) and Midland agroecology (OR=2.5) showed statistically significant seroconversion than cattle kept under small-holder dairy farms and Highland agroecology respectively (p<0.05). Reproductive disorders including abortion, retention of the fetal membranes, and metritis were associated with serostatus of SBV. In conclusion, the seroprevalence of SBV is high and widely distributed in the studied parts of Ethiopia. This being the first study of its kind on SBV in Ethiopia, further

  3. West Nile Virus workshop: scientific considerations for tissue donors.

    Science.gov (United States)

    Brubaker, Scott A; Robert Rigney, P

    2012-08-01

    This report contains selected excerpts, presented as a summary, from a public workshop sponsored by the American Association of Tissue Banks (AATB) held to discuss West Nile Virus (WNV) and scientific considerations for tissue donors. The daylong workshop was held 9 July 2010 at the Ritz-Carlton Hotel at Tyson's Corner in McLean, Virginia, United States (U.S.). The workshop was designed to determine and discuss scientific information that is known, and what is not known, regarding WNV infection and transmission. The goal is to determine how to fill gaps in knowledge of WNV and tissue donation and transplantation by pursuing relevant scientific studies. This information should ultimately support decisions leading to appropriate tissue donor screening and testing considerations. Discussion topics were related to identifying these gaps and determining possible solutions. Workshop participants included subject-matter experts from the U.S. Food and Drug Administration, the Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, Health Canada, the Public Health Agency of Canada, AATB-accredited tissue banks including reproductive tissue banks, accredited eye banks of the Eye Bank Association of America, testing laboratories, and infectious disease and organ transplantation professionals. After all presentations concluded, a panel addressed this question: "What are the scientific considerations for tissue donors and what research could be performed to address those considerations?" The slide presentations from the workshop are available at: http://www.aatb.org/2010-West-Nile-Virus-Workshop-Presentations.

  4. West Nile virus and North America: an unfolding story.

    Science.gov (United States)

    Glaser, A

    2004-08-01

    Before the introduction of the West Nile virus (WNV) into the United States of America (USA) in 1999, conditions in North America were ideal for an arboviral epidemic. Such factors as the large, susceptible and non-immune animal and human populations, the presence of competent vectors, increasing international travel and commerce, existing methods for rapid dissemination and an ill-prepared animal and public health infrastructure all combined to create the essential elements for a severe animal and public health crisis--the 'perfect microbial storm'. The introduction of WNV into New York City was the final factor, serving as the catalyst to initiate one of the most significant epidemics in the USA. The spread of WNV across the country resulted in very large populations of wildlife, equines and people being exposed and infected. The epidemic is still not fully understood and its character continues to change and adapt. The recent recognition of a number of non-vector modes of transmission has revealed the disease as a greater threat and more difficult to control than first thought. West Nile virus gives every indication that it will become a permanent part of the 'medical landscape' of the USA, continuing to threaten wildlife, domestic animals and humans as a now endemic disease. This paper discusses the features of this extraordinary epidemic, and emphasises the need for an integrated surveillance system, greater diagnostic capacity and improved control strategies.

  5. High Zika Virus Seroprevalence in Salvador, Northeastern Brazil Limits the Potential for Further Outbreaks

    Directory of Open Access Journals (Sweden)

    Eduardo Martins Netto

    2017-11-01

    Full Text Available During 2015 to 2016, Brazil reported more Zika virus (ZIKV cases than any other country, yet population exposure remains unknown. Serological studies of ZIKV are hampered by cross-reactive immune responses against heterologous viruses. We conducted serosurveys for ZIKV, dengue virus (DENV, and Chikungunya virus (CHIKV in 633 individuals prospectively sampled during 2015 to 2016, including microcephaly and non-microcephaly pregnancies, HIV-infected patients, tuberculosis patients, and university staff in Salvador in northeastern Brazil using enzyme-linked immunosorbent assays (ELISAs and plaque reduction neutralization tests. Sera sampled retrospectively during 2013 to 2015 from 277 HIV-infected patients were used to assess the spread of ZIKV over time. Individuals were georeferenced, and sociodemographic indicators were compared between ZIKV-positive and -negative areas and areas with and without microcephaly cases. Epidemiological key parameters were modeled in a Bayesian framework. ZIKV seroprevalence increased rapidly during 2015 to 2016, reaching 63.3% by 2016 (95% confidence interval [CI], 59.4 to 66.8%, comparable to the seroprevalence of DENV (75.7%; CI, 69.4 to 81.1% and higher than that of CHIKV (7.4%; CI, 5.6 to 9.8%. Of 19 microcephaly pregnancies, 94.7% showed ZIKV IgG antibodies, compared to 69.3% of 257 non-microcephaly pregnancies (P = 0.017. Analyses of sociodemographic data revealed a higher ZIKV burden in low socioeconomic status (SES areas. High seroprevalence, combined with case data dynamics allowed estimates of the basic reproduction number R0 of 2.1 (CI, 1.8 to 2.5 at the onset of the outbreak and an effective reproductive number Reff of <1 in subsequent years. Our data corroborate ZIKV-associated congenital disease and an association of low SES and ZIKV infection and suggest that population immunity caused cessation of the outbreak. Similar studies from other areas will be required to determine the fate of the American

  6. Can reconstructed land surface temperature data from space predict a West Nile Virus outbreak?

    NARCIS (Netherlands)

    Andreo, V.; Metz, J.C.M.; Neteler, M.; Rosà, R.; Marcantonio, M.; Billinis, C.; Rizzoli, A.; Papa, Anne-Laure

    2017-01-01

    Temperature is one of the main drivers of ecological processes. The availability of temporally and spatially continuous temperature time series is crucial in different research and application fields, such as epidemiology and control of zoonotic diseases. In 2010, several West Nile virus (WNV)

  7. Diagnosis of West Nile Virus Human Infections: Overview and Proposal of Diagnostic Protocols Considering the Results of External Quality Assessment Studies

    Directory of Open Access Journals (Sweden)

    Ana Vázquez

    2013-09-01

    Full Text Available West Nile virus, genus Flavivirus, is transmitted between birds and occasionally other animals by ornithophilic mosquitoes. This virus also infects humans causing asymptomatic infections in about 85% of cases and <1% of clinical cases progress to severe neuroinvasive disease. The virus also presents a threat since most infections remain unapparent. However, the virus contained in blood and organs from asymptomatically infected donors can be transmitted to recipients of these infectious tissues. This paper reviews the presently available methods to achieve the laboratory diagnosis of West Nile virus infections in humans, discussing the most prominent advantages and disadvantages of each in light of the results obtained during four different External Quality Assessment studies carried out by the European Network for ‘Imported’ Viral Diseases (ENIVD.

  8. Dynamics of West Nile virus persistence in House Sparrows (Passer domesticus.

    Directory of Open Access Journals (Sweden)

    Sarah S Wheeler

    Full Text Available West Nile Virus (WNV is now endemic throughout North America, with annual recurrence dependent upon successful overwintering when cold temperatures drive mosquito vectors into inactivity and halt transmission. To investigate whether avian hosts may serve as an overwintering mechanism, groups of eight to ten House Sparrows were experimentally infected with a WN02 genotype of WNV and then held until necropsy at 3, 5, 7, 9, 12, 15, or 18 weeks post-infection (pi when they were assessed for the presence of persistent infection. Blood was collected from all remaining birds every two weeks pi, and sera tested for WNV RNA and WNV neutralizing antibodies. West Nile virus RNA was present in the sera of some birds up to 7 weeks pi and all birds retained neutralizing antibodies throughout the experiment. The detection of persistently infected birds decreased with time, from 100% (n = 13 positive at 3 weeks post-infection (pi to 12.5% (n = 8 at 18 weeks pi. Infectious virus was isolated from the spleens of birds necropsied at 3, 5, 7 and 12 weeks pi. The current study confirmed previous reports of infectious WNV persistence in avian hosts, and further characterized the temporal nature of these infections. Although these persistent infections supported the hypothesis that infected birds may serve as an overwintering mechanism, mosquito-infectious recrudescent viremias have yet to be demonstrated thereby providing proof of principle.

  9. Seroprevalence of herpes simplex virus 2 among Hispanics in the USA: National Health and Nutrition Examination Survey, 2007-2008.

    Science.gov (United States)

    Molina, M; Romaguera, R A; Valentine, J; Tao, G

    2011-07-01

    To examine the seroprevalence of herpes simplex virus type 2 (HSV-2) among Hispanics in the USA, we used the cross-sectional, nationally representative National Health and Nutrition Examination Survey to compare the seroprevalence of HSV-2 between Hispanic persons of Mexican heritage and non-Mexican heritage aged 14-44 years, from survey years 2007-2008. The overall HSV-2 seroprevalence among Hispanics aged 14-44 years was 17.5% (95% confidence interval [CI], 15.2, 20.1) in the USA. HSV-2 seroprevalence was significantly lower among Mexican Americans than among other Hispanics (11.7% vs. 27.8%, P heritage and non-Mexican heritage suggested that targeting specific subgroups of Hispanics for preventive interventions may be a strategy to reduce the transmission of HSV-2 and HIV among Hispanics in the USA.

  10. Community diversity of mosquitoes and their microbes across different habitats endemic for West Nile Virus and other arthropod-borne diseases

    Science.gov (United States)

    Liu, R.; Bennett, S. N.; Thongsripong, P.; Chandler, J. S.

    2013-12-01

    Mosquitoes have long been vectors for disease, and humans, birds, and other vertebrates have served their role as hosts in the transmission cycle of arthropod-borne viruses. In California, there are several mosquito species that act as vectors, transmitting such disease agents as Western equine and St. Louis encephalitis viruses, filarial nematodes, Plasmodium (which causes malaria), and West Nile virus (WNV). Last year (2012-2013), California had over 450 reported cases of West Nile Virus in humans (http://westnile.ca.gov/). To begin to understand mosquitoes and their role in the bay area as vectors of diseases, including West Nile Virus, we trapped mosquitoes from various sites and examined their microbiomes, including bacteria, fungi, viruses, and eukaryotes. Study sites were in Marin, San Mateo, and San Francisco counties, in areas that represented, respectively, rural, suburban, and urban habitats. The mosquitoes were identified through morphological characteristics, and verified molecularly by sequencing of the cytochrome oxidase I (COI) gene extracted from a leg. Most mosquitoes were collected from San Mateo and Mill Valley and were identified as Culiseta incidens. Data from traditional culture-based and next-generation 454 sequencing methods applied to mosquito whole bodies, representing their microbiomes, will be discussed, to determine how mosquito and microbial diversity varies across sites sampled in the San Francisco Bay area.

  11. West Nile Virus in the United States — A Historical Perspective

    Directory of Open Access Journals (Sweden)

    John T. Roehrig

    2013-12-01

    Full Text Available Prior to 1999, West Nile virus (WNV was a bit player in the screenplay of global vector-borne viral diseases. First discovered in the West Nile District of Uganda in 1937, this Culex sp.-transmitted virus was known for causing small human febrile outbreaks in Africa and the Middle East. Prior to 1995, the last major human WNV outbreak was in the 1950s in Israel. The epidemiology and ecology of WNV began to change in the mid-1990s when an epidemic of human encephalitis occurred in Romania. The introduction of WNV into Eastern Europe was readily explained by bird migration between Africa and Europe. The movement of WNV from Africa to Europe could not, however, predict its surprising jump across the Atlantic Ocean to New York City and the surrounding areas of the United States (U.S.. This movement of WNV from the Eastern to Western Hemisphere in 1999, and its subsequent dissemination throughout two continents in less than ten years is widely recognized as one of the most significant events in arbovirology during the last two centuries. This paper documents the early events of the introduction into and the spread of WNV in the Western Hemisphere.

  12. Risk Factors Associated with Ebola and Marburg Viruses Seroprevalence in Blood Donors in the Republic of Congo.

    Directory of Open Access Journals (Sweden)

    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.

  13. Identifying environmental risk factors and mapping the risk of human West Nile virus in South Dakota.

    Science.gov (United States)

    Hess, A.; Davis, J. K.; Wimberly, M. C.

    2017-12-01

    Human West Nile virus (WNV) first arrived in the USA in 1999 and has since then spread across the country. Today, the highest incidence rates are found in the state of South Dakota. The disease occurrence depends on the complex interaction between the mosquito vector, the bird host and the dead-end human host. Understanding the spatial domain of this interaction and being able to identify disease transmission hotspots is crucial for effective disease prevention and mosquito control. In this study we use geospatial environmental information to understand what drives the spatial distribution of cases of human West Nile virus in South Dakota and to map relative infection risk across the state. To map the risk of human West Nile virus in South Dakota, we used geocoded human case data from the years 2004-2016. Satellite data from the Landsat ETM+ and MODIS for the years 2003 to 2016 were used to characterize environmental patterns. From these datasets we calculated indices, such as the normalized differenced vegetation index (NDVI) and the normalized differenced water index (NDWI). In addition, datasets such as the National Land Data Assimilation System (NLDAS), National Land Cover Dataset (NLCD), National Wetland inventory (NWI), National Elevation Dataset (NED) and Soil Survey Geographic Database (SSURGO) were utilized. Environmental variables were summarized for a buffer zone around the case and control points. We used a boosted regression tree model to identify the most important variables describing the risk of WNV infection. We generated a risk map by applying this model across the entire state. We found that the highest relative risk is present in the James River valley in northeastern South Dakota. Factors that were identified as influencing the transmission risk include inter-annual variability of vegetation cover, water availability and temperature. Land covers such as grasslands, low developed areas and wetlands were also found to be good predictors for human

  14. Seroprevalence of feline immunodeficiency virus and feline leukaemia virus in Australia: risk factors for infection and geographical influences (2011–2013

    Directory of Open Access Journals (Sweden)

    Mark E Westman

    2016-05-01

    Full Text Available Objectives Our aim was to: (i determine the current seroprevalence of feline immunodeficiency virus (FIV and feline leukaemia virus (FeLV in three large cohorts of cats from Australia; and (ii investigate potential risk factors for retroviral infection. Methods Cohort 1 (n = 2151 for FIV, n = 2241 for FeLV consisted of cats surrendered to a shelter on the west coast of Australia (Perth, Western Australia [WA]. Cohort 2 (n = 2083 for FIV, n = 2032 for FeLV consisted of client-owned cats with outdoor access recruited from around Australia through participating veterinary clinics. Cohort 3 (n = 169 for FIV, n = 166 for FeLV consisted of cats presenting to Murdoch University Veterinary Hospital for a variety of reasons. Fresh whole blood was collected and tested using a commercially available point-of-care lateral flow ELISA kit that detects p27 FeLV antigen and antibodies to FIV antigens (p15 and p24 (cohorts 1 and 2, or one of two lateral flow immunochromatography kits that detect p27 antigen and antibodies to FIV antigen (p24 and/or gp40 (cohort 3. Data recorded for cats in cohort 2 included signalment, presenting complaint and postcode, allowing investigation of risk factors for FIV or FeLV infection, as well as potential geographical ‘hot spots’ for infection. Results The seroprevalence of FIV was 6% (cohort 1, 15% (cohort 2 and 14% (cohort 3, while the seroprevalence of FeLV was 1%, 2% and 4% in the same respective cohorts. Risk factors for FIV infection among cats in cohort 2 included age (>3 years, sex (male, neutering status (entire males and location (WA had a significantly higher FIV seroprevalence compared with the Australian Capital Territory, New South Wales and Victoria. Risk factors for FeLV infection among cats in cohort 2 included health status (‘sick’ and location (WA cats were approximately three times more likely to be FeLV-infected compared with the rest of Australia. No geographical hot spots of FIV infection were

  15. Seroprevalence of Helicobacter pylori in human immunodeficiency ...

    African Journals Online (AJOL)

    Background: This study assessed the seroprevalence of Helicobacter pylori antibodies among Iranian patients with human immunodeficiency virus (HIV) infection. It also examines whether anti H. pylori seroprevalence was associated with the severity of the HIV infection or the antiretroviral treatment. Material and Methods: ...

  16. Eastern equine encephalitis virus: high seroprevalence in horses from Southern Quebec, Canada, 2012.

    Science.gov (United States)

    Rocheleau, Jean-Philippe; Arsenault, Julie; Lindsay, L Robbin; DiBernardo, Antonia; Kulkarni, Manisha A; Côté, Nathalie; Michel, Pascal

    2013-10-01

    Eastern equine encephalitis virus (EEEV) is a highly pathogenic arbovirus that infects humans, horses, and other animals. There has been a significant increase in EEEV activity in southeastern Canada since 2008. Few data are available regarding nonlethal EEEV infections in mammals, and consequently the distribution and pathogenicity spectrum of EEEV infections in these hosts is poorly understood. This cross-sectional study focuses on the evaluation of viral activity in southern Quebec's horses by seroprevalence estimation. A total of 196 horses, 18 months and older, which had never been vaccinated against EEEV and have never traveled outside Canada, were sampled from 92 barns distributed throughout three administrative regions of southern Quebec. Blood samples were taken from each horse and titrated for EEEV antibodies by plaque reduction neutralization test (PRNT). Equine population vaccination coverage was estimated by surveying horse owners and equine practitioners. PRNT results revealed an EEEV seroprevalence up to 8.7%, with 95% confidence limits ranging from 4.4% to 13.0%. Vaccination coverage was estimated to be at least 79%. Our study reveals for the first time in Canada a measure of EEEV seroprevalence in horses. High seroprevalence in unvaccinated animals challenges the perception that EEEV is a highly lethal pathogen in horses. Monitoring high-risk vector-borne infections such as EEEV in animal populations can be an important element of a public health surveillance strategy, population risk assessment and early detection of epidemics.

  17. West Nile Virus in Resident Birds from Yucatan, Mexico.

    Science.gov (United States)

    Chaves, Andrea; Sotomayor-Bonilla, Jesus; Monge, Otto; Ramírez, Abigaíl; Galindo, Francisco; Sarmiento-Silva, Rosa Elena; Gutiérrez-Espeleta, Gustavo A; Suzán, Gerardo

    2016-01-01

    West Nile virus (WNV) in the Americas is thought to be transported at large spatial scales by migratory birds and locally spread and amplified by resident birds. Local processes, including interspecific interactions and dominance of passerine species recognized as competent reservoirs, may boost infection and maintain endemic cycles. Change in species composition has been recognized as an important driver for infection dynamics. Due to migration and changes in species diversity and composition in wintering grounds, changes in infection prevalence are expected. To these changes, we used PCR to estimate the prevalence of WNV in wild resident birds during the dry and rainy seasons of 2012 in Yucatan, Mexico. Serum samples were obtained from 104 wild birds, belonging to six orders and 35 species. We detected WNV in 14 resident birds, representing 11 species and three orders. Prevalences by order was Passeriformes (27%), Columbiformes (6%), and Piciformes (33%). Resident birds positive to WNV from Yucatan may be indicative of local virus circulation and evidence of past virus transmission activity.

  18. West nile virus anti-body surveillance in three Sierra Nevada raptors of conservation concern

    Science.gov (United States)

    J.M. Hull; J.J. Keane; L.A. Tell; H.B. Ernest

    2010-01-01

    West Nile virus (WNV) infection has caused high levels of mortality in North American hawks and owls. To investigate the extent of infection among raptors of conservation concern in the Sierra Nevada, we tested 62 Northern Goshawks (Accipiter gentilis), 209 Spotted Owls (Strix occidentalis), and 22 Great Gray Owls (...

  19. Comparison of assays for the detection of West Nile virus antibodies in chicken serum

    Czech Academy of Sciences Publication Activity Database

    Weingartl, H. M.; Drebot, M. A.; Hubálek, Zdeněk; Halouzka, Jiří; Andonova, M.; Dibernardo, A.; Cottam-Birt, C.; Larence, J.; Marszal, P.

    2003-01-01

    Roč. 67, č. 2 (2003), s. 128-132 ISSN 0830-9000 Institutional research plan: CEZ:AV0Z6093917 Keywords : West Nile virus Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.101, year: 2003 http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=227040&blobtype=pdf

  20. West Nile virus circulation in South-Eastern Romania, 2011 to 2013.

    Science.gov (United States)

    Dinu, S; Cotar, A I; Pănculescu-Gătej, I R; Fălcuţă, E; Prioteasa, F L; Sîrbu, A; Oprişan, G; Bădescu, D; Reiter, P; Ceianu, C S

    2015-05-21

    Lineage 2 West Nile virus (WNV), previously found only in sub-Saharan Africa and Madagascar, was identified in Hungary in 2004 and has rapidly expanded in Europe in the past decade. Following a significant outbreak of West Nile fever with neurological cases caused by lineage 1 WNV in Romania in 1996, scattered cases have been recorded in the south-east of the country in each transmission season. Another outbreak, affecting a larger area and caused by lineage 2 WNV, was recorded in 2010. We analysed human sera from neuroinvasive West Nile fever cases and mosquitoes, sampled in south-eastern Romania between 2011 and 2013, for the presence of WNV genome, and obtained partial NS5 and envelope glycoprotein sequences. Human- and mosquito-derived WNV sequences were highly similar (99%) to Volgograd 2007 lineage 2 WNV and differed from isolates previously detected in central and southern Europe. WNV was detected in one pool of Culex pipiens s.l. males, documenting vertical transmission. Lineage 4 WNV, of unknown pathogenicity to mammals, was found in the amphibian-feeding mosquito Uranotaenia unguiculata from the Danube Delta. Our results present molecular evidence for the maintenance of the same isolates of Volgograd 2007-like lineage 2 WNV in south-eastern Romania between 2011 and 2013.

  1. Co-circulation of Toscana virus and Punique virus in northern Tunisia: a microneutralisation-based seroprevalence study.

    Directory of Open Access Journals (Sweden)

    Sonia Sakhria

    Full Text Available BACKGROUND: In northern Tunisia, the co-circulation of two related sand fly-borne phleboviruses, Toscana virus (TOSV and Punique virus (PUNV was previously demonstrated. In contrast to TOSV, a prominent human pathogen, there is no data supporting that PUNV is capable to infect and cause disease to humans. We studied the respective involvement of TOSV and PUNV in human infections in northern Tunisia through a seroprevalence study. METHODS: The presence of TOSV and PUNV neutralising antibodies (NT-Ab was tested in human sera collected from 5 districts of the governorate of Bizerte, and the titres of NT-Ab were estimated by microneutralisation (MN assay. PRINCIPAL FINDINGS: A total of 1,273 sera were processed. TOSV and PUNV NT-Ab were detected in 522 (41% and 111 sera (8.72% respectively. TOSV seroprevalence varied from 17.2% to 59.4% depending on the district. Analysis of TOSV geometric mean titre values demonstrated a constant increase according to the age. The vast majority of sera containing NT-Ab were found to be more reactive toward TOSV than PUNV. Indeed, past infections with PUNV and TOSV were undisputable for 5 and 414 sera, respectively. CONCLUSIONS: PUNV may be capable to infect humans but at a low rate. TOSV is responsible for the vast majority of human infections by sand fly-borne phleboviruses in northern Tunisia. TOSV must be considered by physician and tested in diagnostic laboratories for patients with meningitis and unexplained fever in northern Tunisia.

  2. Characterization of a 105-kDa plasma membrane associated glycoprotein that is involved in West Nile virus binding and infection

    International Nuclear Information System (INIS)

    Chu, J.J.H.; Ng, M.L.

    2003-01-01

    This study attempts to isolate and characterize West Nile virus-binding molecules on the plasma membrane of Vero and murine neuroblastoma cells that is responsible for virus entry. Pretreatment of Vero cells with proteases, glycosidases (endoglycosidase H, α-mannosidase), and sodium periodate strongly inhibited West Nile virus infection, whereas treatments with phospholipases and heparinases had no effect. The virus overlay protein blot detected a 105-kDa molecule on the plasma membrane extract of Vero and murine neuroblastoma cells that bind to WN virus. Treatment of the 105-kDa molecules with β-mercaptoethanol resulted in the virus binding to a series of lower molecular weight bands ranging from 30 to 40 kDa. The disruption of disulfide-linked subunits did not affect virus binding. N-linked sugars with mannose residues on the 105-kDa membrane proteins were found to be important in virus binding. Specific antibodies against the 105-kDa glycoprotein were highly effective in blocking virus entry. These results strongly supported the possibility that the 105-kDa protease-sensitive glycoprotein with complex N-linked sugars could be the putative receptor for WN virus

  3. Clinical pathology results from cranes with experimental West Nile Virus infection

    Science.gov (United States)

    Olsen, Glenn H.

    2011-01-01

    Sandhill cranes (Grus canadensis) were vaccinated for and then challenged with West Nile virus. Resulting titers demonstrated protection in the vaccinated-challenged cranes as compared to the unvaccinated-challenged cranes. Clinical pathology results showed challenged cranes, whether vaccinated or not, had a decrease in their hematocrits and an elevation of 2.5-fold in their white blood cell counts as compared to unchallenged control sandhill cranes. No differences were apparent in the differential counts of heterophils and lymphocytes.

  4. Novel flavivirus or new lineage of West Nile Virus, central Europe

    Czech Academy of Sciences Publication Activity Database

    Bakonyi, T.; Hubálek, Zdeněk; Rudolf, Ivo; Nowotny, N.

    2005-01-01

    Roč. 11, č. 2 (2005), s. 225-231 ISSN 1080-6040. [International Conference on Emerging Infectious Diseases . Al Ain, 26.02.2005-01.03.2005] R&D Projects: GA ČR(CZ) GA206/03/0726 Institutional research plan: CEZ:AV0Z60930519 Keywords : epidemiology * West Nile virus * Central Europe Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 5.308, year: 2005 http://www.cdc.gov/ncidod/EID/vol11no02/04-1028.htm

  5. Seroprevalence and Risk Factors of Bluetongue Virus Infection in Tibetan Sheep and Yaks in Tibetan Plateau, China.

    Science.gov (United States)

    Ma, Jian-Gang; Zhang, Xiao-Xuan; Zheng, Wen-Bin; Xu, Ying-Tian; Zhu, Xing-Quan; Hu, Gui-Xue; Zhou, Dong-Hui

    2017-01-01

    Bluetongue (BT), caused by bluetongue virus (BTV), is an arthropod-borne viral disease in ruminants. However, information about BTV infection in yaks in China is limited. Moreover, no such data concerning BTV in Tibetan sheep is available. Therefore, 3771 serum samples were collected from 2187 Tibetan sheep and 1584 yaks between April 2013 and March 2014 from Tibetan Plateau, western China, and tested for BTV antibodies using a commercially available ELISA kit. The overall seroprevalence of BTV was 17.34% (654/3771), with 20.3% (443/2187) in Tibetan sheep and 13.3% (211/1584) in yaks. In the Tibetan sheep group, the seroprevalence of BTV in Luqu, Maqu, Tianzhu, and Nyingchi Prefecture was 20.3%, 20.8%, 20.5%, and 19.1%, respectively. The seroprevalence of BTV in different season groups varied from 16.5% to 23.4%. In the yak group, BTV seroprevalence was 12.6%, 15.5%, and 11.0% in Tianzhu, Maqu, and Luqu counties, respectively. The seroprevalence in different seasons was 12.6%, 15.5%, 15.4%, and 9.0% in spring, summer, autumn, and winter, respectively. The season was the major risk factor concerning BTV infection in yaks ( P Tibetan sheep and yaks provides baseline information for controlling BT in ruminants in western China.

  6. Noncoding Subgenomic Flavivirus RNA Is Processed by the Mosquito RNA Interference Machinery and Determines West Nile Virus Transmission by Culex pipiens Mosquitoes

    NARCIS (Netherlands)

    Goertz, G.P.; Fros, J.J.; Miesen, P.; Vogels, C.B.F.; Bent, M.L. van der; Geertsema, C.; Koenraadt, C.J.M.; Rij, R.P. van; Oers, M.M. van; Pijlman, G.P.

    2016-01-01

    Flaviviruses, such as Zika virus, yellow fever virus, dengue virus, and West Nile virus (WNV), are a serious concern for human health. Flaviviruses produce an abundant noncoding subgenomic flavivirus RNA (sfRNA) in infected cells. sfRNA results from stalling of the host 5'-3' exoribonuclease

  7. Importance of bird-to-bird transmission for the establishment of West Nile virus

    Czech Academy of Sciences Publication Activity Database

    Hartemink, N. A.; Davis, S. A.; Reiter, P.; Hubálek, Zdeněk; Heesterbeek, J. A. P.

    2007-01-01

    Roč. 7, č. 4 (2007), s. 575-584 ISSN 1530-3667 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Source of funding: R - rámcový projekt EK Keywords : West Nile virus * basic reproduction number * direct transmission Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 1.919, year: 2007

  8. Hepatitis C virus infection in South Australian prisoners: seroprevalence, seroconversion, and risk factors.

    Science.gov (United States)

    Miller, Emma Ruth; Bi, Peng; Ryan, Philip

    2009-03-01

    To determine entry antibody seroprevalence and seroconversion to hepatitis C virus (HCV) and associated risk factors in newly incarcerated prisoners. Males and females entering South Australian prisons completed risk factor surveys and were offered HCV-antibody testing. Participants completed additional surveys and, if HCV-negative at last test, underwent further antibody tests at 3-monthly intervals for up to 15 months. Data were analyzed using univariate and multivariate techniques. HCV seroprevalence among 662 prison entrants was estimated at 42%. Previous injecting history was highly prevalent at entry (64%) and both community and prison injecting independently predicted entry HCV status. Tattooing was not an important risk factor. While community exposure could not be ruled out, three seroconversions were noted in 148 initially HCV-seronegative individuals occurring in a median 121 days--4.6 per 100 person-years. Prison injecting was infrequently reported, but HCV-seropositive participants were significantly more likely to commence IDU in prison than seronegative participants (p=0.035). Entry HCV seroprevalence in South Australian prisoners is extremely high and may have contributed to a 'ceiling effect', minimizing the observable seroconversion rate. Greater frequency of injecting among those already infected with HCV represents a significant threat to other prisoners and prison staff.

  9. Seroprevalence of HTLV1,2 Virus Among Injection Drug Addicts in Isfahan, 2007-2008

    Directory of Open Access Journals (Sweden)

    Sh Farzaneh

    2009-10-01

    Full Text Available Introduction: Human T-cell lymphotropic virus (HTLV, is a member of the retroviridae family. Infection with this virus leads to adult T-cell leukemia (ATL and tropical spastic paraparesis (TSP. HTLV is endemic in Japan, parts of central Africa, Caribbean basin and Iran (Mashhad. Transmission routes of HTLV are believed to be from mother to child, especially during breastfeeding, sexual contact, and through blood transfusion or needle sharing. Considering the risk of HTLV infection among injection drug addicts, the authors evaluated the seroprevalence of HTLV1,2 infection among injection drug addicts in Isfahan Methods: This cross sectional study included a total of 150 injection drug users who were recruited at the drug abuse treatment clinic and the infectious diseases department of Alzahra university Hospital. Participants were interviewed using a structured questionnaire. Epidemiologic data were recorded and their blood samples were tested for HBs Ag and antibodies against HTLV1,2, human immunodeficiency virus (HIV and hepatitis C (HCV by Elisa method . Results were analyzed by SPSS software version 13. Results: Seroprevalence of HTLV1,2, HBV(HBs Ag, HCV and HIV was 2.7%, 1.3% 23.3% and 2.7%, respectively. Some of the subjects were co infected with two viruses. One patient was infected with both HCV Ab and HBs Ag , while another was positive for HIV Ab plus HBs Ag . Three were co infected with HCV and HIV. Among those with HTLV1,2, only one was HCV Ab positive. Only in one person with HTLV1,2 Ab had a positive history of blood transfusion. Conclusion: This study shows that this virus is present in injection drug users community of Isfahan and can be a potential source for transmission. But proposal of screening of HTLV1,2 among injection drug users in Isfahan requires further investigations.

  10. Zika virus infection confers protection against West Nile virus challenge in mice.

    Science.gov (United States)

    Vázquez-Calvo, Ángela; Blázquez, Ana-Belén; Escribano-Romero, Estela; Merino-Ramos, Teresa; Saiz, Juan-Carlos; Martín-Acebes, Miguel A; Jiménez de Oya, Nereida

    2017-09-20

    Flaviviruses are RNA viruses that constitute a worrisome threat to global human and animal health. Zika virus (ZIKV), which was initially reported to cause a mild disease, recently spread in the Americas, infecting millions of people. During this recent epidemic, ZIKV infection has been linked to serious neurological diseases and birth defects, specifically Guillain-Barrè syndrome (GBS) and microcephaly. Because information about ZIKV immunity remains scarce, we assessed the humoral response of immunocompetent mice to infection with three viral strains of diverse geographical origin (Africa, Asia and America). No infected animals showed any sign of disease or died after infection. However, specific neutralizing antibodies were elicited in all infected mice. Considering the rapid expansion of ZIKV throughout the American continent and its co-circulation with other medically relevant flaviviruses, such as West Nile virus (WNV), the induction of protective immunity between ZIKV and WNV was analyzed. Remarkably, protection after challenge with WNV was observed in mice previously infected with ZIKV, as survival rates were significantly higher than in control mice. Moreover, previous ZIKV infection enhanced the humoral immune response against WNV. These findings may be relevant in geographical areas where both ZIKV and WNV co-circulate, as well as for the future development of broad-spectrum flavivirus vaccines.

  11. A thiopurine drug inhibits West Nile virus production in cell culture, but not in mice.

    Science.gov (United States)

    Lim, Pei-Yin; Keating, Julie A; Hoover, Spencer; Striker, Rob; Bernard, Kristen A

    2011-01-01

    Many viruses within the Flavivirus genus cause significant disease in humans; however, effective antivirals against these viruses are not currently available. We have previously shown that a thiopurine drug, 6-methylmercaptopurine riboside (6MMPr), inhibits replication of distantly related viruses within the Flaviviridae family in cell culture, including bovine viral diarrhea virus and hepatitis C virus replicon. Here we further examined the potential antiviral effect of 6MMPr on several diverse flaviviruses. In cell culture, 6MMPr inhibited virus production of yellow fever virus, dengue virus-2 (DENV-2) and West Nile virus (WNV) in a dose-dependent manner, and DENV-2 was significantly more sensitive to 6MMPr treatment than WNV. We then explored the use of 6MMPr as an antiviral against WNV in an immunocompetent mouse model. Once a day treatment of mice with 0.5 mg 6MMPr was just below the toxic dose in our mouse model, and this dose was used in subsequent studies. Mice were treated with 6MMPr immediately after subcutaneous inoculation with WNV for eight consecutive days. Treatment with 6MMPr exacerbated weight loss in WNV-inoculated mice and did not significantly affect mortality. We hypothesized that 6MMPr has low bioavailability in the central nervous system (CNS) and examined the effect of pre-treatment with 6MMPr on viral loads in the periphery and CNS. Pre-treatment with 6MMPr had no significant effect on viremia or viral titers in the periphery, but resulted in significantly higher viral loads in the brain, suggesting that the effect of 6MMPr is tissue-dependent. In conclusion, despite being a potent inhibitor of flaviviruses in cell culture, 6MMPr was not effective against West Nile disease in mice; however, further studies are warranted to reduce the toxicity and/or improve the bioavailability of this potential antiviral drug.

  12. A thiopurine drug inhibits West Nile virus production in cell culture, but not in mice.

    Directory of Open Access Journals (Sweden)

    Pei-Yin Lim

    Full Text Available Many viruses within the Flavivirus genus cause significant disease in humans; however, effective antivirals against these viruses are not currently available. We have previously shown that a thiopurine drug, 6-methylmercaptopurine riboside (6MMPr, inhibits replication of distantly related viruses within the Flaviviridae family in cell culture, including bovine viral diarrhea virus and hepatitis C virus replicon. Here we further examined the potential antiviral effect of 6MMPr on several diverse flaviviruses. In cell culture, 6MMPr inhibited virus production of yellow fever virus, dengue virus-2 (DENV-2 and West Nile virus (WNV in a dose-dependent manner, and DENV-2 was significantly more sensitive to 6MMPr treatment than WNV. We then explored the use of 6MMPr as an antiviral against WNV in an immunocompetent mouse model. Once a day treatment of mice with 0.5 mg 6MMPr was just below the toxic dose in our mouse model, and this dose was used in subsequent studies. Mice were treated with 6MMPr immediately after subcutaneous inoculation with WNV for eight consecutive days. Treatment with 6MMPr exacerbated weight loss in WNV-inoculated mice and did not significantly affect mortality. We hypothesized that 6MMPr has low bioavailability in the central nervous system (CNS and examined the effect of pre-treatment with 6MMPr on viral loads in the periphery and CNS. Pre-treatment with 6MMPr had no significant effect on viremia or viral titers in the periphery, but resulted in significantly higher viral loads in the brain, suggesting that the effect of 6MMPr is tissue-dependent. In conclusion, despite being a potent inhibitor of flaviviruses in cell culture, 6MMPr was not effective against West Nile disease in mice; however, further studies are warranted to reduce the toxicity and/or improve the bioavailability of this potential antiviral drug.

  13. A rapid and quantitative assay for measuring antibody-mediated neutralization of West Nile virus infection

    International Nuclear Information System (INIS)

    Pierson, Theodore C.; Sanchez, Melissa D.; Puffer, Bridget A.; Ahmed, Asim A.; Geiss, Brian J.; Valentine, Laura E.; Altamura, Louis A.; Diamond, Michael S.; Doms, Robert W.

    2006-01-01

    West Nile virus (WNV) is a neurotropic flavivirus within the Japanese encephalitis antigenic complex that is responsible for causing West Nile encephalitis in humans. The surface of WNV virions is covered by a highly ordered icosahedral array of envelope proteins that is responsible for mediating attachment and fusion with target cells. These envelope proteins are also primary targets for the generation of neutralizing antibodies in vivo. In this study, we describe a novel approach for measuring antibody-mediated neutralization of WNV infection using virus-like particles that measure infection as a function of reporter gene expression. These reporter virus particles (RVPs) are produced by complementation of a sub-genomic replicon with WNV structural proteins provided in trans using conventional DNA expression vectors. The precision and accuracy of this approach stem from an ability to measure the outcome of the interaction between antibody and viral antigens under conditions that satisfy the assumptions of the law of mass action as applied to virus neutralization. In addition to its quantitative strengths, this approach allows the production of WNV RVPs bearing the prM-E proteins of different WNV strains and mutants, offering considerable flexibility for the study of the humoral immune response to WNV in vitro. WNV RVPs are capable of only a single round of infection, can be used under BSL-2 conditions, and offer a rapid and quantitative approach for detecting virus entry and its inhibition by neutralizing antibody

  14. Ovicidal and larvicidal effects of garlic and asafoetida essential oils against West Nile virus vectors

    Science.gov (United States)

    We examined the chemical composition of garlic and asafoetida essential oils and their individual and combined toxicity against larvae of two West Nile virus vectors, Culex pipiens pipiens and Cx. restuans. The effect of the two essential oils on egg hatch was also examined. Ten and twelve compounds...

  15. A Mouse Model of Chronic West Nile Virus Disease.

    Directory of Open Access Journals (Sweden)

    Jessica B Graham

    2016-11-01

    Full Text Available Infection with West Nile virus (WNV leads to a range of disease outcomes, including chronic infection, though lack of a robust mouse model of chronic WNV infection has precluded identification of the immune events contributing to persistent infection. Using the Collaborative Cross, a population of recombinant inbred mouse strains with high levels of standing genetic variation, we have identified a mouse model of persistent WNV disease, with persistence of viral loads within the brain. Compared to lines exhibiting no disease or marked disease, the F1 cross CC(032x013F1 displays a strong immunoregulatory signature upon infection that correlates with restraint of the WNV-directed cytolytic response. We hypothesize that this regulatory T cell response sufficiently restrains the immune response such that a chronic infection can be maintained in the CNS. Use of this new mouse model of chronic neuroinvasive virus will be critical in developing improved strategies to prevent prolonged disease in humans.

  16. Seroprevalence of Epstein-Barr virus infection in U.S. children ages 6-19, 2003-2010.

    Directory of Open Access Journals (Sweden)

    Jennifer Beam Dowd

    Full Text Available BACKGROUND: Epstein-Barr virus (EBV is a common herpesvirus linked to infectious mononucleosis and multiple cancers. There are no national estimates of EBV seroprevalence in the United States. Our objective was to estimate the overall prevalence and sociodemographic predictors of EBV among U.S. children and adolescents aged 6-19. METHODS: We calculated prevalence estimates and prevalence ratios for EBV seroprevalence using data from the 2003-2010 U.S. National Health and Nutrition Examination Survey (NHANES for children aged 6-19 (n = 8417. Poisson regression was used to calculate multivariable-adjusted prevalence ratios across subgroup categories (sex, race/ethnicity, parental education, household income, household size, foreign-born, BMI, and household smoking. FINDINGS: Overall EBV seroprevalence was 66.5% (95% CI 64.3%-68.7%.. Seroprevalence increased with age, ranging from 54.1% (95% CI 50.2%-57.9% for 6-8 year olds to 82.9% (95% CI 80.0%-85.9% for 18-19 year olds. Females had slightly higher seroprevalence (68.9%, 95% CI 66.3%-71.6% compared to males (64.2%, 95% CI 61.7%-66.8%. Seroprevalence was substantially higher for Mexican-Americans (85.4%, 95% CI 83.1%-87.8% and Non-Hispanic Blacks (83.1%, 95% CI 81.1%-85.1% than Non-Hispanic Whites (56.9%, 95% CI 54.1%-59.8%. Large differences were also seen by family income, with children in the lowest income quartile having 81.0% (95% CI 77.6%-84.5% seroprevalence compared to 53.9% (95% CI 50.5%-57.3% in the highest income quartile, with similar results for parental education level. These results were not explained by household size, BMI, or parental smoking. Among those who were seropositive, EBV antibody titers were significantly higher for females, Non-Hispanic Blacks and Mexican-Americans, with no association found for socioeconomic factors. CONCLUSIONS: In the first nationally representative U.S. estimates, we found substantial socioeconomic and race/ethnic differences in the

  17. Seroprevalence and factors associated with bovine viral diarrhea virus (BVDV) infection in dairy cattle in three milksheds in Ethiopia.

    Science.gov (United States)

    Aragaw, Kassaye; Sibhat, Berhanu; Ayelet, Gelagay; Skjerve, Eystein; Gebremedhin, Endrias Z; Asmare, Kassahun

    2018-05-31

    This work was conducted to estimate the seroprevalence, to identify potential factors that influence seroprevalence of bovine viral diarrhea virus (BVDV), and to investigate the association between BVDV serostatus and occurrence of reproductive disorders in dairy cattle in three milksheds in Ethiopia. A total of 1379 serum samples were obtained from cattle randomly selected from 149 herds from three milksheds representing central, southern, and western Ethiopia. Sera samples were examined for bovine viral diarrhea virus (BVDV) antibodies using commercial competitive enzyme-linked immunosorbent assay (ELISA) kit. Logistic regression analysis was employed to investigate associations between risk factors and the risk of BVDV seroprevalence, and BVDV serostatus and reproductive disorders. Seroreaction to BVDV antigens was detected in 32.6% of the 1379 cattle and 69.8% of the 149 herds sampled. Factors associated with BVDV seroplevalence were age, breed, and herd size (P  0.05). Risk of reproductive disorders was not affected by BVDV serostatus, except for repeat breeding (P > 0.05). The present study demonstrated that BVDV has wide distribution in the country being detected in all the 15 conurbations and 69.8% of herds involved in the study.

  18. Mechanism of West Nile Virus Neuroinvasion: A Critical Appraisal

    Directory of Open Access Journals (Sweden)

    Willy W. Suen

    2014-07-01

    Full Text Available West Nile virus (WNV is an important emerging neurotropic virus, responsible for increasingly severe encephalitis outbreaks in humans and horses worldwide. However, the mechanism by which the virus gains entry to the brain (neuroinvasion remains poorly understood. Hypotheses of hematogenous and transneural entry have been proposed for WNV neuroinvasion, which revolve mainly around the concepts of blood-brain barrier (BBB disruption and retrograde axonal transport, respectively. However, an over‑representation of in vitro studies without adequate in vivo validation continues to obscure our understanding of the mechanism(s. Furthermore, WNV infection in the current rodent models does not generate a similar viremia and character of CNS infection, as seen in the common target hosts, humans and horses. These differences ultimately question the applicability of rodent models for pathogenesis investigations. Finally, the role of several barriers against CNS insults, such as the blood-cerebrospinal fluid (CSF, the CSF-brain and the blood-spinal cord barriers, remain largely unexplored, highlighting the infancy of this field. In this review, a systematic and critical appraisal of the current evidence relevant to the possible mechanism(s of WNV neuroinvasion is conducted.

  19. Globalization, land use and the invasion of West Nile virus

    Science.gov (United States)

    Kilpatrick, A. Marm

    2012-01-01

    Many invasive species that have been spread through the globalization of trade and travel are infectious pathogens. A paradigmatic case is the introduction of West Nile virus (WNV) into North America in 1999. A decade of research on the ecology and evolution of WNV includes three findings that provide insight into the outcome of future viral introductions. First, WNV transmission in North America is highest in urbanized and agricultural habitats, in part because the hosts and vectors of WNV are abundant in human-modified areas. Second, after its introduction, the virus quickly adapted to infect local mosquito vectors more efficiently than the originally introduced strain. Third, highly focused feeding patterns of the mosquito vectors of WNV result in unexpected host species being important for transmission. These findings provide a framework for predicting and preventing the emergence of foreign vector-borne pathogens. PMID:22021850

  20. Seroprevalence of antibodies to avian influenza A (H5 and A (H9 viruses among market poultry workers, Hanoi, Vietnam, 2001.

    Directory of Open Access Journals (Sweden)

    Timothy M Uyeki

    Full Text Available BACKGROUND: The frequency of avian influenza A virus infections among poultry workers is not well understood. METHODS: A seroprevalence study of market poultry workers and persons without occupational poultry exposure was conducted during 2001 in Hanoi, Vietnam. Sera were tested for avian influenza H5 and H9 antibodies by microneutralization and Western blot assays. RESULTS: Seroprevalence of H5 and H9 antibodies was 4% and 3% in poultry workers and 1% and 3.5% in non-poultry workers, respectively. CONCLUSIONS: Seroprevalence of H5 and H9 antibodies was low among Hanoi market poultry workers in 2001, but can serve as a baseline for additional studies.

  1. Seroprevalence of Antibodies to Avian Influenza A (H5) and A (H9) Viruses among Market Poultry Workers, Hanoi, Vietnam, 2001

    Science.gov (United States)

    Rowe, Thomas; Lu, Xiuhua; Hu-Primmer, Jean; Huynh, Lien P.; Hang, Nguyen L. K.; Katz, Jacqueline M.

    2012-01-01

    Background The frequency of avian influenza A virus infections among poultry workers is not well understood. Methods A seroprevalence study of market poultry workers and persons without occupational poultry exposure was conducted during 2001 in Hanoi, Vietnam. Sera were tested for avian influenza H5 and H9 antibodies by microneutralization and Western blot assays. Results Seroprevalence of H5 and H9 antibodies was 4% and 3% in poultry workers and 1% and 3.5% in non-poultry workers, respectively. Conclusions Seroprevalence of H5 and H9 antibodies was low among Hanoi market poultry workers in 2001, but can serve as a baseline for additional studies. PMID:22928049

  2. SEROLOGIC EVIDENCE OF WEST NILE VIRUS INFECTION IN BIRDS, TAMAULIPAS STATE, MEXICO

    OpenAIRE

    beaty, barry; FERNANDEZ, ILDEFONSO; contreras, juan francisco; blitvich, bradley; gonzalez, jose ignacio; cavazos, amanda a; loroño, maria alba; gluber, duante j.; Cropp, bruce; Calisher , Charles

    2003-01-01

    Following the introduction of West Nile virus (WNV) into North America in 1999, surveillance for WNV in migratory and resident birds was established in Tamaulipas State, northern Mexico in December 2001. Overall, 796 birds representing 70 species and 10 orders were captured and assayed for antibodies to WNV. Nine birds had flavivirus-specific antibodies by epitope-blocking enzyme-linked immunosorbent assay; four were confirmed to have antibody to WNV by plaque reduction neutralization test. T...

  3. Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections

    OpenAIRE

    Hua, Rong-Hong; Chen, Na-Sha; Qin, Cheng-Feng; Deng, Yong-Qiang; Ge, Jin-Ying; Wang, Xi-Jun; Qiao, Zu-Jian; Chen, Wei-Ye; Wen, Zhi-Yuan; Liu, Wen-Xin; Hu, Sen; Bu, Zhi-Gao

    2010-01-01

    Abstract Background Differential diagnose of Japanese encephalitis virus (JEV) infection from other flavivirus especially West Nile virus (WNV) and Dengue virus (DV) infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV. Results To map the epitopes on the P...

  4. NMR analysis of the dynamic exchange of the NS2B cofactor between open and closed conformations of the West Nile virus NS2B-NS3 protease.

    Directory of Open Access Journals (Sweden)

    Xun-Cheng Su

    Full Text Available BACKGROUND: The two-component NS2B-NS3 proteases of West Nile and dengue viruses are essential for viral replication and established targets for drug development. In all crystal structures of the proteases to date, the NS2B cofactor is located far from the substrate binding site (open conformation in the absence of inhibitor and lining the substrate binding site (closed conformation in the presence of an inhibitor. METHODS: In this work, nuclear magnetic resonance (NMR spectroscopy of isotope and spin-labeled samples of the West Nile virus protease was used to investigate the occurrence of equilibria between open and closed conformations in solution. FINDINGS: In solution, the closed form of the West Nile virus protease is the predominant conformation irrespective of the presence or absence of inhibitors. Nonetheless, dissociation of the C-terminal part of the NS2B cofactor from the NS3 protease (open conformation occurs in both the presence and the absence of inhibitors. Low-molecular-weight inhibitors can shift the conformational exchange equilibria so that over 90% of the West Nile virus protease molecules assume the closed conformation. The West Nile virus protease differs from the dengue virus protease, where the open conformation is the predominant form in the absence of inhibitors. CONCLUSION: Partial dissociation of NS2B from NS3 has implications for the way in which the NS3 protease can be positioned with respect to the host cell membrane when NS2B is membrane associated via N- and C-terminal segments present in the polyprotein. In the case of the West Nile virus protease, discovery of low-molecular-weight inhibitors that act by breaking the association of the NS2B cofactor with the NS3 protease is impeded by the natural affinity of the cofactor to the NS3 protease. The same strategy can be more successful in the case of the dengue virus NS2B-NS3 protease.

  5. Human Monoclonal Antibodies against West Nile Virus Induced by Natural Infection Neutralize at a Postattachment Step

    NARCIS (Netherlands)

    Vogt, Matthew R.; Moesker, Bastiaan; Goudsmit, Jaap; Jongeneelen, Mandy; Austin, S. Kyle; Oliphant, Theodore; Nelson, Steevenson; Pierson, Theodore C.; Wilschut, Jan; Throsby, Mark; Diamond, Michael S.

    West Nile virus (WNV) is a neurotropic flavivirus that is now a primary cause of epidemic encephalitis in North America. Studies of mice have demonstrated that the humoral immune response against WNV limits primary infection and protects against a secondary challenge. The most-potent neutralizing

  6. Hepatitis E virus infection in North Italy: high seroprevalence in swine herds and increased risk for swine workers.

    NARCIS (Netherlands)

    Mughini-Gras, L; Angeloni, G; Salata, C; Vonesch, N; D'Amico, W; Campagna, G; Natale, A; Zuliani, F; Ceglie, L; Monne, I; Vascellari, M; Capello, K; DI Martino, G; Inglese, N; Palù, G; Tomao, P; Bonfanti, L

    2017-01-01

    We determined the hepatitis E virus (HEV) seroprevalence and detection rate in commercial swine herds in Italy's utmost pig-rich area, and assessed HEV seropositivity risk in humans as a function of occupational exposure to pigs, diet, foreign travel, medical history and hunting activities. During

  7. Hepatitis E virus infection in North Italy : high seroprevalence in swine herds and increased risk for swine workers

    NARCIS (Netherlands)

    Mughini-Gras, L|info:eu-repo/dai/nl/413306046; Angeloni, Giorgia; Salata, C; Vonesch, N; D'Amico, W; Campagna, G; Natale, Alda; Zuliani, Federica; Ceglie, Letizia; Monne, Isabella; Vascellari, M; Capello, Katia; DI Martino, G; Inglese, N; Palù, G; Tomao, P; Bonfanti, L.

    2017-01-01

    We determined the hepatitis E virus (HEV) seroprevalence and detection rate in commercial swine herds in Italy's utmost pig-rich area, and assessed HEV seropositivity risk in humans as a function of occupational exposure to pigs, diet, foreign travel, medical history and hunting activities. During

  8. West Nile Virus RNA in Tissues from Donor Associated with Transmission to Organ Transplant Recipients

    Centers for Disease Control (CDC) Podcasts

    2013-11-19

    William Hale reads an abridged version of the Emerging Infectious Diseases’ dispatch, West Nile Virus RNA in Tissues from Donor Associated with Transmission to Organ Transplant Recipients.  Created: 11/19/2013 by National Center for Emerging and Zoonotic Infectious Diseases (NCEZID).   Date Released: 11/21/2013.

  9. Phocine distemper virus (PDV) seroprevalence as predictor for future outbreaks in harbour seals.

    Science.gov (United States)

    Ludes-Wehrmeister, Eva; Dupke, Claudia; Harder, Timm C; Baumgärtner, Wolfgang; Haas, Ludwig; Teilmann, Jonas; Dietz, Rune; Jensen, Lasse F; Siebert, Ursula

    2016-02-01

    Phocine distemper virus (PDV) infections caused the two most pronounced mass mortalities in marine mammals documented in the past century. During the two outbreaks, 23,000 and 30,000 harbour seals (Phoca vitulina), died in 1988/1989 and 2002 across populations in the Wadden Sea and adjacent waters, respectively. To follow the mechanism and development of disease spreading, the dynamics of Morbillivirus-specific antibodies in harbour seal populations in German and Danish waters were examined. 522 serum samples of free-ranging harbour seals of different ages were sampled between 1990 and 2014. By standard neutralisation assays, Morbillivirus-specific antibodies were detected, using either the PDV isolate 2558/Han 88 or the related canine distemper virus (CDV) strain Onderstepoort. A total of 159 (30.5%) of the harbour seals were seropositive. Annual seroprevalence rates showed an undulating course: Peaks were seen in the post-epidemic years 1990/1991 and 2002/2003. Following each PDV outbreak, seroprevalence decreased and six to eight years after the epidemics samples were tested seronegative, indicating that the populations are now again susceptible to new PDV outbreak. After the last outbreak in 2002, the populations grew steadily to an estimated maximum (since 1975) of about 39,100 individuals in the Wadden Sea in 2014 and about 23,540 harbour seals in the Kattegat area in 2013. A re-appearence of PDV would presumably result in another epizootic with high mortality rates as encountered in the previous outbreaks. The current high population density renders harbour seals vulnerable to rapid spread of infectious agents including PDV and the recently detected influenza A virus. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Culex quinquefasciatus (Diptera: Culicidae as a potential West Nile virus vector in Tucson, Arizona: Blood meal analysis indicates feeding on both humans and birds

    Directory of Open Access Journals (Sweden)

    Margaret Zinser

    2004-06-01

    Full Text Available Most reports from the United States suggest Culex quinquefasciatus mosquitoes feed minimally on humans. Given the abundance of C. quinquefasciatus in residential Tucson and parts of metropolitan Phoenix, and the arrival of West Nile virus to this area, discovering the blood meal hosts of the local population is important. Using a sandwich ELISA technique, the local C. quinquefasciatus were found to feed on both humans and birds. This suggests they should be considered potential West Nile virus vectors.

  11. The Integrated System for Public Health Monitoring of West Nile Virus (ISPHM-WNV: a real-time GIS for surveillance and decision-making

    Directory of Open Access Journals (Sweden)

    Lebel Germain

    2005-09-01

    Full Text Available Abstract Background After its first detection in North America in New York in 1999, West Nile virus was detected for the first time in 2002 in the province of Quebec, Canada. This situation forced the Government of Quebec to adopt a public health protection plan against the virus. The plan comprises several fields of intervention including the monitoring of human cases, Corvidae and mosquitoes in order to ensure the early detection of the presence of the virus in a particular area. To help support the monitoring activities, the Integrated System for Public Health Monitoring of West Nile Virus (ISPHM-WNV has been developed. Results The ISPHM-WNV is a real-time geographic information system for public health surveillance of West Nile virus and includes information on Corvidae, mosquitoes, humans, horses, climate, and preventive larvicide interventions. It has been in operation in the province of Quebec, Canada, since May 2003. The ISPHM-WNV facilitates the collection, localization, management and analysis of monitoring data; it also allows for the display of the results of analyses on maps, tables and statistical diagrams. Conclusion The system is very helpful for field workers in all regions of the province, as well as for central authorities. It represents the common authoritative source of data for analysis, exchange and decision-making.

  12. Occurrence of west nile virus infection in raptors at the Salton Sea, California.

    Science.gov (United States)

    Dusek, Robert J; Iko, William M; Hofmeister, Erik K

    2010-07-01

    We investigated the prevalence of West Nile virus (WNV)-neutralizing antibodies and infectious virus, and the occurrence of overwinter transmission in two raptor species during January and March 2006 at the Salton Sea, Imperial County, California. We captured 208 American Kestrels (Falco sparverius) (January, n=100; March, n=108) and 116 Burrowing Owls (Athene cunicularia) (January, n=52; March, n=64). Laboratory analysis revealed that 83% of American Kestrels and 31% of Burrowing Owls were positive for WNV-neutralizing antibodies. Additionally, two seroconversions were detected in Burrowing Owls between January and March. Infectious WNV, consistent with acute infection, was not detected in any bird.

  13. Occurrence of West Nile virus infection in raptors at the Salton Sea, California

    Science.gov (United States)

    Dusek, Robert J.; Iko, William M.; Hofmeister, Erik K.

    2010-01-01

    We investigated the prevalence of West Nile virus (WNV)-neutralizing antibodies and infectious virus, and the occurrence of overwinter transmission in two raptor species during January and March 2006 at the Salton Sea, Imperial County, California. We captured 208 American Kestrels (Falco sparverius) (January, n=100; March, n=108) and 116 Burrowing Owls (Athene cunicularia) (January, n=52; March, n=64). Laboratory analysis revealed that 83% of American Kestrels and 31% of Burrowing Owls were positive for WNV-neutralizing antibodies. Additionally, two seroconversions were detected in Burrowing Owls between January and March. Infectious WNV, consistent with acute infection, was not detected in any bird.

  14. Serosurvey Reveals Exposure to West Nile Virus in Asymptomatic Horse Populations in Central Spain Prior to Recent Disease Foci.

    Science.gov (United States)

    Abad-Cobo, A; Llorente, F; Barbero, M Del Carmen; Cruz-López, F; Forés, P; Jiménez-Clavero, M Á

    2017-10-01

    West Nile fever/encephalitis (WNF) is an infectious disease affecting horses, birds and humans, with a cycle involving birds as natural reservoirs and mosquitoes as transmission vectors. It is a notifiable disease, re-emerging in Europe. In Spain, it first appeared in horses in the south (Andalusia) in 2010, where outbreaks occur every year since. However, in 2014, an outbreak was declared in horses in central Spain, approximately 200 km away from the closest foci in Andalusia. Before that, evidence of West Nile virus (WNV) circulation in central Spain had been obtained only from wildlife, but never in horses. The purpose of this work was to perform a serosurvey to retrospectively detect West Nile virus infections in asymptomatic horses in central Spain from 2011 to 2013, that is before the occurrence of the first outbreaks in the area. For that, serum samples from 369 horses, collected between September 2011 and November 2013 in central Spain, were analysed by ELISA (blocking and IgM) and confirmed by virus neutralization, proving its specificity using parallel titration with another flavivirus (Usutu virus). As a result, 10 of 369 horse serum samples analysed gave positive results by competitive ELISA, 5 of which were confirmed as positive to WNV by virus neutralization (seropositivity rate: 1.35%). One of these WNV seropositive samples was IgM-positive. Chronologically, the first positive samples, including the IgM-positive, corresponded to sera collected in 2012 in Madrid province. From these results, we concluded that WNV circulated in asymptomatic equine populations of central Spain at least since 2012, before the first disease outbreak reported in this area. © 2016 Blackwell Verlag GmbH.

  15. West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus)--management strategies to optimize survival.

    Science.gov (United States)

    Harasym, Carol A

    2008-11-01

    In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality.

  16. Seroprevalence of Antibodies to Avian Influenza A (H5) and A (H9) Viruses among Market Poultry Workers, Hanoi, Vietnam, 2001

    OpenAIRE

    Uyeki, Timothy M.; Nguyen, Doan C.; Rowe, Thomas; Lu, Xiuhua; Hu-Primmer, Jean; Huynh, Lien P.; Hang, Nguyen L. K.; Katz, Jacqueline M.

    2012-01-01

    BACKGROUND: The frequency of avian influenza A virus infections among poultry workers is not well understood. METHODS: A seroprevalence study of market poultry workers and persons without occupational poultry exposure was conducted during 2001 in Hanoi, Vietnam. Sera were tested for avian influenza H5 and H9 antibodies by microneutralization and Western blot assays. RESULTS: Seroprevalence of H5 and H9 antibodies was 4% and 3% in poultry workers and 1% and 3.5% in non-poultry workers, respect...

  17. Seroprevalence of hepatitis A virus in a cross-sectional study in Mexico: Implications for hepatitis A vaccination.

    Science.gov (United States)

    Lazcano-Ponce, Eduardo; Conde-Gonzalez, Carlos; Rojas, Rosalba; DeAntonio, Rodrigo; Romano-Mazzotti, Luis; Cervantes, Yolanda; Ortega-Barria, Eduardo

    2013-02-01

    Hepatitis A virus (HAV) remains a public health concern worldwide contributing to significant morbidity in developed and developing countries. This cross-sectional database study estimated the overall HAV seroprevalence and the seroprevalence by gender, age, region and socioeconomic status in Mexico. Between January and October 2010, serum samples collected during the National Health and Nutrition survey (ENSANUT 2006) were obtained from subjects aged 1-95 y. Subjects' gender, age, geographical region and socioeconomic status were extracted from the survey and compiled into a subset database by the Mexican National Institute of Public Health. Anti-HAV antibodies were measured using a chemiluminescent immunoassay. A total of 3658 subjects were included in the according-to-protocol cohort. Overall, the HAV seroprevalence was 84.2%. The HAV seroprevalence rates were similar between females (86.1%) and males (82.2%). The percentage of subjects seropositive for anti-HAV antibodies was highest in adults aged ≥ 20 y (96.9%), followed by adolescents aged 10-19 y (80.1%) and lowest in children aged 1-9 y (45.0%) (p < 0.0001). Regionally, the highest HAV seroprevalence rate was observed in the South (88.8%) followed by Central and Northern Mexico and Mexico City (p = 0.02). The HAV seroprevalence was similar between subjects of high socioeconomic (90.1%) status and of low socioeconomic status (86.6%). This study confirms the intermediate HAV endemicity in Mexico. Cost-effectiveness studies are necessary to evaluate the inclusion of an effective hepatitis A vaccine from a population-based perspective in addition to continuous efforts to improve hygiene and sanitation that have a substantial impact on the disease burden.

  18. Influenza C virus high seroprevalence rates observed in 3 different population groups.

    Science.gov (United States)

    Salez, Nicolas; Mélade, Julien; Pascalis, Hervé; Aherfi, Sarah; Dellagi, Koussay; Charrel, Rémi N; Carrat, Fabrice; de Lamballerie, Xavier

    2014-08-01

    The epidemiology of Influenza C virus (FLUCV) infections remains poorly characterised. Here, we have examined the age- and location-specific seroprevalence of antibodies against FLUCV in 1441 sera from metropolitan continental France (Marseille), South-West Indian Ocean French territories (Reunion Island) and United-Kingdom (Edinburgh) using a combination of haemagglutination inhibition, virus neutralisation and ELISA assays. Our results show that immunity to FLUCV is common in all locations studied (global seroprevalence values >50%) and that the first immunising contacts generally occur early in life (i.e., in the 0-4 year-old age group). The latter item is further supported by the detection of FLUCV RNA by RT-PCR in naso-pharyngeal samples collected in patient attending the Emergency Room of the Public hospitals of Marseille, France with a large majority of children under 10 years-old: 17 (60.7%) in children ≤3 yo, 10 (35.7%) in the 4-10 yo age group and 1 (3.6%) in an adult (49yo). The temporal distribution of cases was atypical with regard to influenza (a large proportion of cases occurred in spring and summer) and the clinical presentation was diverse, including but being not limited to classical Influenza-like-Ilnesses. Altogether, our results indicate an intense circulation of FLUCV in the different study areas and an early occurrence of infection in human life. Flu C appears to be a widely under-diagnosed and under-studied human paediatric disease that obviously deserves further clinical and epidemiological characterisation. Copyright © 2014 The British Infection Association. Published by Elsevier Ltd. All rights reserved.

  19. Persistence of Antibodies to West Nile Virus in Naturally Infected Rock Pigeons (Columba livia)

    Science.gov (United States)

    Gibbs, Samantha E. J.; Hoffman, Douglas M.; Stark, Lillian M.; Marlenee, Nicole L.; Blitvich, Bradley J.; Beaty, Barry J.; Stallknecht, David E.

    2005-01-01

    Wild caught rock pigeons (Columba livia) with antibodies to West Nile virus were monitored for 15 months to determine antibody persistence and compare results of three serologic techniques. Antibodies persisted for the entire study as detected by epitope-blocking enzyme-linked immunosorbent assay and plaque reduction neutralization test. Maternal antibodies in squabs derived from seropositive birds persisted for an average of 27 days. PMID:15879030

  20. Transmission of West Nile virus by Culex quinquefasciatus say infected with Culex Flavivirus Izabal.

    Directory of Open Access Journals (Sweden)

    Rebekah J Kent

    Full Text Available BACKGROUND: The natural history and potential impact of mosquito-specific flaviviruses on the transmission efficiency of West Nile virus (WNV is unknown. The objective of this study was to determine whether or not prior infection with Culex flavivirus (CxFV Izabal altered the vector competence of Cx. quinquefasciatus Say for transmission of a co-circulating strain of West Nile virus (WNV from Guatemala. METHODS AND FINDINGS: CxFV-negative Culex quinquefasciatus and those infected with CxFV Izabal by intrathoracic inoculation were administered WNV-infectious blood meals. Infection, dissemination, and transmission of WNV were measured by plaque titration on Vero cells of individual mosquito bodies, legs, or saliva, respectively, two weeks following WNV exposure. Additional groups of Cx. quinquefasciatus were intrathoracically inoculated with WNV alone or WNV+CxFV Izabal simultaneously, and saliva collected nine days post inoculation. Growth of WNV in Aedes albopictus C6/36 cells or Cx. quinquefasciatus was not inhibited by prior infection with CxFV Izabal. There was no significant difference in the vector competence of Cx. quinquefasciatus for WNV between mosquitoes uninfected or infected with CxFV Izabal across multiple WNV blood meal titers and two colonies of Cx. quinquefasciatus (p>0.05. However, significantly more Cx. quinquefasciatus from Honduras that were co-inoculated simultaneously with both viruses transmitted WNV than those inoculated with WNV alone (p = 0.0014. Co-inoculated mosquitoes that transmitted WNV also contained CxFV in their saliva, whereas mosquitoes inoculated with CxFV alone did not contain virus in their saliva. CONCLUSIONS: In the sequential infection experiments, prior infection with CxFV Izabal had no significant impact on WNV replication, infection, dissemination, or transmission by Cx. quinquefasciatus, however WNV transmission was enhanced in the Honduras colony when mosquitoes were inoculated simultaneously with

  1. West Nile virus infection of birds, Mexico.

    Science.gov (United States)

    Guerrero-Sánchez, Sergio; Cuevas-Romero, Sandra; Nemeth, Nicole M; Trujillo-Olivera, María Teresa Jesús; Worwa, Gabriella; Dupuis, Alan; Brault, Aaron C; Kramer, Laura D; Komar, Nicholas; Estrada-Franco, José Guillermo

    2011-12-01

    West Nile virus (WNV) has caused disease in humans, equids, and birds at lower frequency in Mexico than in the United States. We hypothesized that the seemingly reduced virulence in Mexico was caused by attenuation of the Tabasco strain from southeastern Mexico, resulting in lower viremia than that caused by the Tecate strain from the more northern location of Baja California. During 2006-2008, we tested this hypothesis in candidate avian amplifying hosts: domestic chickens, rock pigeons, house sparrows, great-tailed grackles, and clay-colored thrushes. Only great-tailed grackles and house sparrows were competent amplifying hosts for both strains, and deaths occurred in each species. Tecate strain viremia levels were higher for thrushes. Both strains produced low-level viremia in pigeons and chickens. Our results suggest that certain avian hosts within Mexico are competent for efficient amplification of both northern and southern WNV strains and that both strains likely contribute to bird deaths.

  2. Characterization of the functional requirements of West Nile virus membrane fusion.

    Science.gov (United States)

    Moesker, Bastiaan; Rodenhuis-Zybert, Izabela A; Meijerhof, Tjarko; Wilschut, Jan; Smit, Jolanda M

    2010-02-01

    Flaviviruses infect their host cells by a membrane fusion reaction. In this study, we performed a functional analysis of the membrane fusion properties of West Nile virus (WNV) with liposomal target membranes. Membrane fusion was monitored continuously using a lipid mixing assay involving the fluorophore, pyrene. Fusion of WNV with liposomes occurred on the timescale of seconds and was strictly dependent on mildly acidic pH. Optimal fusion kinetics were observed at pH 6.3, the threshold for fusion being pH 6.9. Preincubation of the virus alone at pH 6.3 resulted in a rapid loss of fusion capacity. WNV fusion activity is strongly promoted by the presence of cholesterol in the target membrane. Furthermore, we provide direct evidence that cleavage of prM to M is a requirement for fusion activity of WNV.

  3. Seroprevalence of hepatitis E virus differs in Dutch and first generation migrant populations in Amsterdam, the Netherlands: a cross-sectional study.

    Science.gov (United States)

    Sadik, S; van Rijckevorsel, G G C; van Rooijen, M S; Sonder, G J B; Bruisten, S M

    2016-11-08

    In the last decade hepatitis E virus (HEV) is increasingly recognized as a cause of acute viral hepatitis in developed countries. HEV is transmitted via the fecal-oral route. In countries like the Netherlands, HEV infection is suspected to be a zoonosis but HEV may also be introduced by migrants. We studied the seroprevalence of HEV among different migrants, mainly Moroccans and Turks, and compared this to that of the native Dutch population in Amsterdam, the Netherlands. Data were obtained from a cross-sectional survey of the adult Amsterdam population performed in 2004; the Amsterdam Health Monitor. A total of 1199 plasma samples were tested for IgG-and IgM antibodies to HEV using the Wantai kit according to instructions of the manufacturer. Basic demographic data (gender, age, country of birth, and age at immigration) were used in the analyses. Hepatitis A virus (HAV) serology data were available from a previous study. The total weighted anti-HEV IgG seroprevalence in the overall Amsterdam population was 26.7 %, based on 1199 samples. In the study population (not-weighted) this HEV seroprevalence was 157/426 (36.9 %) for the Dutch participants and it was 161/257 (62.6 %) for Moroccans, 99/296 (33.4 %) for Turks and 42/220 (19.1 %) for other ethnicities. HEV seroprevalence increased significantly with age. First-generation Moroccan migrants (44.0 %) had a significantly higher weighted HEV seroprevalence than the Dutch participants (29.7 %). In the first generation Turks (20.3 %) and first generation migrants from other countries (16.7 %) this weighted seroprevalence was lower, but this was only significant for the 'other ethnicities'. The median age of migration was significantly higher in the Moroccan and Turkish migrants who were HEV IgG positive versus HEV IgG negative. However, when stratifying for age at time of study, median migration age was only significantly different for HEV sero-status for younger Turks and younger 'other ethnicities'. HEV Ig

  4. Seroprevalence and distribution of arboviral infections among rural Kenyan adults: A cross-sectional study

    Directory of Open Access Journals (Sweden)

    Schoepp Randal J

    2011-07-01

    Full Text Available Abstract Background Arthorpod-borne viruses (arboviruses cause wide-spread morbidity in sub-Saharan Africa, but little research has documented the burden and distribution of these pathogens. Methods Using a population-based, cross-sectional study design, we administered a detailed questionnaire and used ELISA to test the blood of 1,141 healthy Kenyan adults from three districts for the presence of anti-viral Immunoglobulin G (IgG antibodies to the following viruses: dengue (DENV, West Nile (WNV, yellow fever (YFV, Chikungunya (CHIKV, and Rift Valley fever (RVFV. Results Of these, 14.4% were positive for DENV, 9.5% were WNV positive, 9.2% were YFV positive, 34.0% were positive for CHIKV and 0.7% were RVFV positive. In total, 46.6% had antibodies to at least one of these arboviruses. Conclusions For all arboviruses, district of residence was strongly associated with seropositivity. Seroprevalence to YFV, DENV and WNV increased with age, while there was no correlation between age and seropositivity for CHIKV, suggesting that much of the seropositivity to CHIKV is due to sporadic epidemics. Paradoxically, literacy was associated with increased seropositivity of CHIKV and DENV.

  5. First detection of West Nile virus in domestic pigeon in Korea.

    Science.gov (United States)

    Kim, C-Yoon; Oh, Hanseul; Song, Juha; Hur, Moonsuk; Suh, Jae-Hwa; Jheong, Weon-Hwa; Kim, Jong-Taek; Oh, Hong-Shik; Park, Jae-Hak

    2016-12-30

    West Nile virus (WNV) is a mosquito-borne zoonotic pathogen that has spread throughout Europe and the United States. Recently, WNV spread to East and Southeast Asia, and great efforts have been made in South Korea to prevent the spread of WNV from neighboring countries. In this study, we diagnosed the first case of WNV in pigeons ( Columba livia domestica ) residing in cities using a competitive enzyme-linked immunosorbent assay and confirmed it with nested reverse transcription polymerase chain reaction analysis and sequencing. This is the first report to provide convincing evidence that WNV is present within South Korea.

  6. Second International Diagnostic Accuracy Study for the Serological Detection of West Nile Virus Infection

    OpenAIRE

    Sanchini, Andrea; Donoso-Mantke, Oliver; Papa, Anna; Sambri, Vittorio; Teichmann, Anette; Niedrig, Matthias

    2013-01-01

    Background: In recent decades, sporadic cases and outbreaks in humans of West Nile virus (WNV) infection have increased. Serological diagnosis of WNV infection can be performed by enzyme-linked immunosorbent assay (ELISA), immunofluorescence assay (IFA) neutralization test (NT) and by hemagglutination-inhibition assay. The aim of this study is to collect updated information regarding the performance accuracy of WNV serological diagnostics. Methodology/Principal findings: In 2011, the E...

  7. Hepatitis E seroprevalence in the Americas: A systematic review and meta-analysis.

    Science.gov (United States)

    Horvatits, Thomas; Ozga, Ann-Kathrin; Westhölter, Dirk; Hartl, Johannes; Manthey, Carolin F; Lütgehetmann, Marc; Rauch, Geraldine; Kriston, Levente; Lohse, Ansgar W; Bendall, Richard; Wedemeyer, Heiner; Dalton, Harry R; Pischke, Sven

    2018-04-16

    While hepatitis E virus infections are a relevant topic in Europe, knowledge about epidemiology of hepatitis E virus infections in the USA and Latin America is still limited. Aim of this study was to estimate anti-hepatitis E virus IgG seroprevalence in the Americas and to assess whether low socioeconomic status is associated with hepatitis E virus exposure. We performed a systematic review and meta-analysis. Literature search was performed in PubMed for articles published 01/1994-12/2016. Prevalence was estimated using a mixed-effects model and reported in line with PRISMA reporting guidelines. Seroprevalence was significantly higher in the USA than in Latin America, independently of assay, patient cohort, methodological quality or study year (OR: 1.82 (1.06-3.08), P = .03). Patients in the USA had a more than doubled estimated seroprevalence (up to 9%, confidence interval 5%-15.6%) than those in Brazil (up to 4.2%, confidence interval 2.4%-7.1%; OR: 2.27 (1.25-4.13); P = .007) and Mixed Caribbean (up to 1%, OR: 8.33 (1.15-81.61); P = .04). A comparison with published data from Europe demonstrated that anti-hepatitis E virus seroprevalence in the USA and Europe did not differ significantly (OR: 1.33 (0.81-2.19), P = .25), while rate in South America was significantly lower than that in Europe (OR: 0.67 (0.45-0.98), P = .04). Hepatitis E virus is common in the USA. Surprisingly, the risk of hepatitis E virus exposure was low in many South American countries. Seroprevalence did not differ significantly between Europe and the USA. Hence, hepatitis E virus is not limited to countries with low sanitary standards, and a higher socioeconomic status does not protect populations from hepatitis E virus exposure. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus) — management strategies to optimize survival

    OpenAIRE

    Harasym, Carol A.

    2008-01-01

    In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality.

  9. West Nile virus and hemoparasites in captive snowy owls (Bubo scandiacus) — management strategies to optimize survival

    Science.gov (United States)

    Harasym, Carol A.

    2008-01-01

    In August 2005, 2 members of a group of 6 captive snowy owls (Bubo scandiacus) in central Saskatchewan died of West Nile virus infection. One of these owls and 3 of the remaining owls had significant numbers of circulating hemoparasites. Management strategies are suggested to reduce morbidity and mortality. PMID:19183740

  10. 21 CFR 866.3940 - West Nile virus serological reagents.

    Science.gov (United States)

    2010-04-01

    ... (CONTINUED) MEDICAL DEVICES IMMUNOLOGY AND MICROBIOLOGY DEVICES Serological Reagents § 866.3940 West Nile... detection aids in the clinical laboratory diagnosis of viral meningitis/encephalitis caused by West Nile...

  11. Pathology of fatal lineage 1 and 2 West Nile virus infections in horses in South Africa

    Directory of Open Access Journals (Sweden)

    June H. Williams

    2014-09-01

    Full Text Available Since 2007, West Nile virus (WNV has been reported in South African horses, causing severe neurological signs. All cases were of lineage 2, except for one case that clustered with lineage 1 viruses. In the present study, gross and microscopic lesions of six South African lineage 2-infected horses and the one lineage 1 case are described. Diagnoses were confirmed by real-time reverse-transcriptase polymerase chain reaction (RT-PCR of central nervous system (CNS tissue and one by RT-PCR of a brain virus isolate. The CNS of all cases was negative by RT-PCR or immunohistochemistry (IHC for African horse sickness (AHS, equine encephalosis virus, equine herpes viruses 1 and 4, other zoonotic flaviviruses, alphaviruses, and shunivirus, and either by immunofluorescence or IHC for rabies. Gross visceral lesions were nonspecific but often mimicked those of AHS. The CNS histopathology of WNV lineage 2 cases resembled the nonsuppurative polioencephalomyelitis reported in the Northern Hemisphere lineage 1 and recent Hungarian lineage 2 cases. Occasional meningitis, focal spinal ventral horn poliomalacia, dorsal and lateral horn poliomyelitis, leucomyelitis, asymmetrical ventral motor spinal neuritis and frequent olfactory region involvement were also seen. Lineage 2 cases displayed marked variations in CNS lesion severity, type and distribution, and suggested various viral entry routes into the CNS, based on findings in experimental mice and hamsters. Lineage 1 lesions were comparable to the milder lineage 2 cases. West Nile virus IHC on CNS sections with marked lesions from all cases elicited only two antigen-positive cells in the olfactory cortex of one case. The presence in the CNS of T-lymphocytes, B-lymphocytes, plasma cells and macrophage-monocytes was confirmed by cluster of differentiation (CD 3, CD20, multiple myeloma oncogene 1 (MUM1 and macrophage (MAC 387 IHC.

  12. Large Human Outbreak of West Nile Virus Infection in North-Eastern Italy in 2012

    Directory of Open Access Journals (Sweden)

    Luisa Barzon

    2013-11-01

    Full Text Available Human cases of West Nile virus (WNV disease have been reported in Italy since 2008. So far, most cases have been identified in north-eastern Italy, where, in 2012, the largest outbreak of WNV infection ever recorded in Italy occurred. Most cases of the 2012 outbreak were identified in the Veneto region, where a special surveillance plan for West Nile fever was in place. In this outbreak, 25 cases of West Nile neuroinvasive disease and 17 cases of fever were confirmed. In addition, 14 WNV RNA-positive blood donors were identified by screening of blood and organ donations and two cases of asymptomatic infection were diagnosed by active surveillance of subjects at risk of WNV exposure. Two cases of death due to WNND were reported. Molecular testing demonstrated the presence of WNV lineage 1 in all WNV RNA-positive patients and, in 15 cases, infection by the novel Livenza strain was ascertained. Surveillance in other Italian regions notified one case of neuroinvasive disease in the south of Italy and two cases in Sardinia. Integrated surveillance for WNV infection remains a public health priority in Italy and vector control activities have been strengthened in areas of WNV circulation.

  13. Seroprevalence and Risk Factors for Human Immunodeficiency ...

    African Journals Online (AJOL)

    This study sought to determine the seroprevalence of human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B surface antigen (HBsAg) among blood donors at Bolga-tanga Regional Hospital, Ghana by blood group type, sex and age and also determining the asso-ciation, if any, in the occurrence of the ...

  14. Overwintering of Uranotaenia unguiculata adult females in central Europe: a possible way of persistence of the putative new lineage of West Nile virus?

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Šebesta, Oldřich; Straková, Petra; Betášová, Lenka; Blažejová, Hana; Venclíková, Kristýna; Seidel, B.; Tóth, S.; Hubálek, Zdeněk; Schaffner, F.

    2015-01-01

    Roč. 31, č. 4 (2015), s. 364-365 ISSN 8756-971X EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : mosquito * mosquito-borne viruses * overwintering * Uranotaenia unguiculata * West Nile virus Subject RIV: EE - Microbiology, Virology Impact factor: 0.824, year: 2015

  15. Seroprevalence of Borrelia burgdorferi sensu lato and tick-borne encephalitis virus in zoo animal species in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Širmarová, J.; Tichá, L.; Golovchenko, Maryna; Salát, Jiří; Grubhoffer, L.; Rudenko, Natalia; Nowotny, N.; Růžek, Daniel

    2014-01-01

    Roč. 5, č. 5 (2014), s. 523-527 ISSN 1877-959X R&D Projects: GA ČR GAP502/11/2116 Institutional support: RVO:60077344 Keywords : Tick-borne encephalitis virus * Borrelia burgdorferi sensu lato * Lyme borreliosis * Seroprevalence * Zoo animals Subject RIV: EE - Microbiology, Virology Impact factor: 2.718, year: 2014

  16. Seroprevalence of hepatitis C virus among people living with HIV/AIDS in Latin America and the Caribbean: a systematic review

    Directory of Open Access Journals (Sweden)

    Fatima Mitiko Tengan

    2016-11-01

    Full Text Available Abstract Background Studies have shown that the immunosuppression induced by the human immunodeficiency virus (HIV accelerates the natural history of liver disease associated with hepatitis C virus (HCV, with 3- to 5-fold higher odds of coinfected individuals developing cirrhosis. However, estimates of the seroprevalence of hepatitis C among people living with HIV/acquired immune deficiency syndrome (AIDS (PLHA in Latin America and the Caribbean (LAC are widely variable. Methods We performed a systematic review to estimate the seroprevalence of HCV among PLHA. We searched studies on HIV and HCV infections in LAC included in the PubMed, LILACS and Embase databases in December of 2014 with no time or language restrictions. The following combinations of search terms were used in the PubMed and Embase databases: (HIV OR Acquired Immunodeficiency Syndrome Virus OR AIDS OR HTLV OR Human Immunodeficiency Virus OR Human T Cell AND (HCV OR HEPATITIS C OR HEPATITIS C VIRUS OR HEPACIVIRUS AND (name of an individual country or territory in LAC. The following search terms were used in the LILACS database: (HIV OR AIDS OR Virus da Imunodeficiencia Humana AND (HCV OR Hepatite C OR Hepacivirus. An additional 11 studies were identified through manual searches. A total of 2,380 publications were located, including 617 duplicates; the remaining articles were reviewed to select studies for inclusion in this study. Results A total of 37 studies were selected for systematic review, including 23 from Brazil, 5 from Argentina, 3 from Cuba, 1 from Puerto Rico, 1 from Chile, 1 from Colombia, 1 from Mexico, 1 from Peru and 1 from Venezuela. The estimated seroprevalence of HCV infection varied from 0.8 to 58.5 % (mean 17.37; median 10.91, with the highest in Argentina and Brazil and the lowest in Venezuela and Colombia. Conclusions Investigation of HCV infection among PLHA and of HIV infection among people living with HCV is highly recommended because it allows for better

  17. Seroprevalence and factors associated with seropositivity to equine arteritis virus in Spanish Purebred horses in Spain.

    Science.gov (United States)

    Cruz, F; Fores, P; Mughini-Gras, L; Ireland, J; Moreno, M A; Newton, R

    2016-09-01

    Equine viral arteritis (EVA), a disease caused by infection with the equine arteritis virus (EAV), is present in many European countries. In Spain, the last confirmed outbreak was reported in 1992 and there is a paucity of seroprevalence studies. The disease has a major impact on the equine breeding industry, which is mainly represented by Spanish Purebred (SP) horses in Spain. To estimate the seroprevalence of EAV in the breeding SP horse population in central Spain and identify potential horse and studfarm level factors associated with seropositivity to EAV. Cross-sectional study. Individual serum samples from 555 SP horses, collected between September 2011 and November 2013 at 35 studfarms, were tested using a commercially available EAV antibody ELISA and seroneutralisation as the World Organisation for Animal Health reference confirmation test for samples with positive and equivocal results. Data on factors putatively associated with seropositivity to EAV were collected via a questionnaire and examined using random effects logistic regression for analysis of clustered data. Equine arteritis virus seroprevalence in the SP breeding population in central Spain standardised for the sex distribution of the reference horse population, was estimated to be 16.8% (95% confidence interval 5.2-28.5%). Increasing numbers of breeding mares on the studfarm and increasing percentage of mares with reproductive problems during the last 12 months were identified as being positively associated with EAV seropositivity. Mares vaccinated against Equine herpesvirus-1 (EHV-1) and/or -4 (EHV-4) were also positively associated with EAV seropositivity. These findings are of importance to ensure appropriate biosecurity measures for studfarms are carried out and may help facilitate the development of an EVA surveillance programme in the SP breeding horse population. © 2015 EVJ Ltd.

  18. West Nile Virus Surveillance in 2013 via Mosquito Screening in Northern Italy and the Influence of Weather on Virus Circulation

    Science.gov (United States)

    Calzolari, Mattia; Pautasso, Alessandra; Montarsi, Fabrizio; Albieri, Alessandro; Bellini, Romeo; Bonilauri, Paolo; Defilippo, Francesco; Lelli, Davide; Moreno, Ana; Chiari, Mario; Tamba, Marco; Zanoni, Mariagrazia; Varisco, Giorgio; Bertolini, Silvia; Modesto, Paola; Radaelli, Maria Cristina; Iulini, Barbara; Prearo, Marino; Ravagnan, Silvia; Cazzin, Stefania; Mulatti, Paolo; Monne, Isabella; Bonfanti, Lebana; Marangon, Stefano; Goffredo, Maria; Savini, Giovanni; Martini, Simone; Mosca, Andrea; Farioli, Marco; Gemma Brenzoni, Laura; Palei, Manlio; Russo, Francesca; Natalini, Silvano; Angelini, Paola; Casalone, Cristina; Dottori, Michele; Capelli, Gioia

    2015-01-01

    West Nile virus (WNV) is a recently re-emerged health problem in Europe. In Italy, an increasing number of outbreaks of West Nile disease, with occurrences of human cases, have been reported since 2008. This is particularly true in northern Italy, where entomological surveillance systems have been implemented at a regional level. The aim of this study was to use, for the first time, all the entomological data collected in the five regions undergoing surveillance for WNV in northern Italy to characterize the viral circulation (at a spatial and temporal scale), identify potential mosquito vectors, and specify relationships between virus circulation and meteorological conditions. In 2013, 286 sites covering the entire Pianura Padana area were monitored. A total of 757,461 mosquitoes were sampled. Of these, 562,079 were tested by real-time PCR in 9,268 pools, of which 180 (1.9%) were positive for WNV. The largest part of the detected WNV sequences belonged to lineage II, demonstrating that, unlike those in the past, the 2013 outbreak was mainly sustained by this WNV lineage. This surveillance also detected the Usutu virus, a WNV-related flavivirus, in 241 (2.6%) pools. The WNV surveillance systems precisely identified the area affected by the virus and detected the viral circulation approximately two weeks before the occurrence of onset of human cases. Ninety percent of the sampled mosquitoes were Culex pipiens, and 178/180 WNV-positive pools were composed of only this species, suggesting this mosquito is the main WNV vector in northern Italy. A significantly higher abundance of the vector was recorded in the WNV circulation area, which was characterized by warmer and less rainy conditions and greater evapotranspiration compared to the rest of the Pianura Padana, suggesting that areas exposed to these conditions are more suitable for WNV circulation. This observation highlights warmer and less rainy conditions as factors able to enhance WNV circulation and cause virus

  19. West Nile Virus Surveillance in 2013 via Mosquito Screening in Northern Italy and the Influence of Weather on Virus Circulation.

    Directory of Open Access Journals (Sweden)

    Mattia Calzolari

    Full Text Available West Nile virus (WNV is a recently re-emerged health problem in Europe. In Italy, an increasing number of outbreaks of West Nile disease, with occurrences of human cases, have been reported since 2008. This is particularly true in northern Italy, where entomological surveillance systems have been implemented at a regional level. The aim of this study was to use, for the first time, all the entomological data collected in the five regions undergoing surveillance for WNV in northern Italy to characterize the viral circulation (at a spatial and temporal scale, identify potential mosquito vectors, and specify relationships between virus circulation and meteorological conditions. In 2013, 286 sites covering the entire Pianura Padana area were monitored. A total of 757,461 mosquitoes were sampled. Of these, 562,079 were tested by real-time PCR in 9,268 pools, of which 180 (1.9% were positive for WNV. The largest part of the detected WNV sequences belonged to lineage II, demonstrating that, unlike those in the past, the 2013 outbreak was mainly sustained by this WNV lineage. This surveillance also detected the Usutu virus, a WNV-related flavivirus, in 241 (2.6% pools. The WNV surveillance systems precisely identified the area affected by the virus and detected the viral circulation approximately two weeks before the occurrence of onset of human cases. Ninety percent of the sampled mosquitoes were Culex pipiens, and 178/180 WNV-positive pools were composed of only this species, suggesting this mosquito is the main WNV vector in northern Italy. A significantly higher abundance of the vector was recorded in the WNV circulation area, which was characterized by warmer and less rainy conditions and greater evapotranspiration compared to the rest of the Pianura Padana, suggesting that areas exposed to these conditions are more suitable for WNV circulation. This observation highlights warmer and less rainy conditions as factors able to enhance WNV circulation

  20. The West Nile virus assembly process evades the conserved antiviral mechanism of the interferon-induced MxA protein

    Energy Technology Data Exchange (ETDEWEB)

    Hoenen, Antje [School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane (Australia); Gillespie, Leah [Department of Microbiology, La Trobe University, Melbourne (Australia); Department of Microbiology and Immunology, University of Melbourne, Melbourne (Australia); Morgan, Garry; Heide, Peter van der [Institute for Molecular Bioscience, University of Queensland, Brisbane (Australia); Khromykh, Alexander [School of Chemistry and Molecular Biosciences, University of Queensland, Brisbane (Australia); Australian Infectious Diseases Research Centre, University of Queensland, Brisbane (Australia); Mackenzie, Jason, E-mail: jason.mackenzie@unimelb.edu.au [Department of Microbiology, La Trobe University, Melbourne (Australia); Department of Microbiology and Immunology, University of Melbourne, Melbourne (Australia)

    2014-01-05

    Flaviviruses have evolved means to evade host innate immune responses. Recent evidence suggests this is due to prevention of interferon production and signaling in flavivirus-infected cells. Here we show that the interferon-induced MxA protein can sequester the West Nile virus strain Kunjin virus (WNV{sub KUN}) capsid protein in cytoplasmic tubular structures in an expression-replication system. This sequestering resulted in reduced titers of secreted WNV{sub KUN} particles. We show by electron microscopy, tomography and 3D modeling that these cytoplasmic tubular structures form organized bundles. Additionally we show that recombinant ER-targeted MxA can restrict production of infectious WNV{sub KUN} under conditions of virus infection. Our results indicate a co-ordinated and compartmentalized WNV{sub KUN} assembly process may prevent recognition of viral components by MxA, particularly the capsid protein. This recognition can be exploited if MxA is targeted to intracellular sites of WNV{sub KUN} assembly. This results in further understanding of the mechanisms of flavivirus evasion from the immune system. - Highlights: • We show that the ISG MxA can recognize the West Nile virus capsid protein. • Interaction between WNV C protein and MxA induces cytoplasmic fibrils. • MxA can be retargeted to the ER to restrict WNV particle release. • WNV assembly process is a strategy to avoid MxA recognition.

  1. Experimental infection of Tilapia Lake Virus (TiLV) in Nile tilapia (Oreochromis niloticus) and red tilapia (Oreochromis spp.).

    Science.gov (United States)

    Tattiyapong, Puntanat; Dachavichitlead, Worawan; Surachetpong, Win

    2017-08-01

    Since 2015, a novel orthomyxo-like virus, tilapia lake virus (TiLV) has been associated with outbreaks of disease and massive mortality of cultured Nile and red tilapia (Oreochromis niloticus and Oreochromis spp., respectively) in Thailand. In this study, TiLV was isolated from field samples and propagated in the permissive E-11 cell line, with cytopathic effect (CPE) development within 3-5days post-inoculation. Electron micrographs of infected E-11 cells and fish tissues confirmed the rounded, enveloped virions of 60 to 80nm with characteristics very similar to those of Orthomyxoviridae. In vivo challenge studies showed that high mortality in Nile (86%) and red tilapia (66%) occurred within 4-12days post-infection. The virus was re-isolated from challenged fish tissues in the permissive cell line, and PCR analysis confirmed TiLV as a causative pathogen. The distinct histopathology of challenged fish included massive degeneration and inflammatory cell infiltration in the liver and brain as well as the presence of eosinophilic intracytoplasmic inclusions in hepatocytes and splenic cells. Our results fulfilled Koch's postulates and confirmed that TiLV is an etiologic agent of mass mortality of tilapia in Thailand. The emergence of this virus in many countries has helped increase awareness that it is a potential threat to tilapia aquacultured in Thailand, Asia, and worldwide. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Population-based study on the seroprevalence of hepatitis A, B, and C virus infection in Amsterdam, 2004.

    Science.gov (United States)

    Baaten, G G G; Sonder, G J B; Dukers, N H T M; Coutinho, R A; Van den Hoek, J A R

    2007-12-01

    In order to enhance screening and preventive strategies, this study investigated the seroprevalence of hepatitis A, B, and C in the general adult urban population and in subgroups. In 2004, sera from 1,364 adult residents of Amsterdam were tested for viral markers. Sociodemographic characteristics were collected using a standardized questionnaire. For hepatitis A, 57.0% was immune. Of first-generation immigrants from Turkey and Morocco, 100% was immune. Of all Western persons and second-generation non-Western immigrants, approximately half was still susceptible. For hepatitis B, 9.9% had antibodies to hepatitis B core antigen (anti-HBc) and 0.4% had hepatitis B surface antigen. Anti-HBc seroprevalences were highest among first-generation immigrants from Surinam, Morocco, and Turkey, and correlated with age at the time of immigration, and among men with a sexual preference for men. Seroprevalence among second-generation immigrants was comparable to Western persons. The seroprevalence of hepatitis C virus antibodies was 0.6%. In conclusion, a country with overall low endemicity for viral hepatitis can show higher endemicity in urban regions, indicating the need for differentiated regional studies and prevention strategies. More prevention efforts in cities like Amsterdam are warranted, particularly for hepatitis A and B among second-generation immigrants, for hepatitis B among men with a sexual preference for men, and for hepatitis C. Active case finding strategies are needed for both hepatitis B and C. (c) Wiley-Liss, Inc.

  3. Seroprevalence of Hepatitis C Viral Antibodies among Pregnant ...

    African Journals Online (AJOL)

    Hepatitis C virus (HCV) infection is an important health problem with an increasing number of patients acquiring the virus. Some infected patients are known to develop liver cirrhosis and /or possible hepatocellular carcinoma. This study was designed to find out the seroprevalence of hepatitis C viral antibodies among ...

  4. Rapid Active Assay for the Detection of Antibodies to West Nile Virus in Chickens

    Science.gov (United States)

    2008-01-01

    and organ donations ,9 breast feeding,10 intrauterine exposure,11 and laboratory pro- cedures,12 emphasizing the importance of developing a rapid and... milk in 20 mmol/L Tris-HCl, 0.15 mol/L NaCl, and 0.05% Tween-20, pH 7.5) was applied to the plates, followed by incubation at room temperature for 30...884–895. 10. Centers for Disease Control and Prevention, 2002. Possible West Nile virus transmission to an infant through breast -feeding— Michigan, 2002

  5. West Nile Flavivirus Polioencephalomyelitis in a harbor seal (Phoca vitulina).

    Science.gov (United States)

    Del Piero, F; Stremme, D W; Habecker, P L; Cantile, C

    2006-01-01

    A 12-year-old male harbor seal presented with progressive signs of neurologic dysfunction including head tremors, muzzle twitching, clonic spasms, and weakness. Lesions included polioencephalomyelitis with glial nodules, spheroids, neuronophagia, ring hemorrhages, and a few neutrophils. Neurons, fibers, and glial nodules were multifocally colonized with intracytoplasmic West Nile flavivirus antigens that were demonstrated using indirect immunohistochemical analysis. Flavivirus on cultured cells also was isolated and was identified by use of monoclonal antibodies and reverse transcriptase-polymerase chain reaction analysis. Clinical signs of disease and lesion morphology and distribution were similar to those of equine West Nile virus infection. Similar to horses, alpacas, humans, dogs, and reptiles, seals can be dead-end hosts of West Nile virus.

  6. The Importance of Haematological and Biochemical Findings in Patients with West Nile Virus Neuroinvasive Disease

    Directory of Open Access Journals (Sweden)

    Urošević Aleksandar

    2016-10-01

    Full Text Available Background: West Nile virus neuroinvasive disease (WNND occurs in less than 1% of infected people. Leukocytosis with lymphocytopenia, mild anaemia, thrombocytopenia, elevated liver and muscle enzymes and hyponatremia are occasionally present in patients with WNND. Cerebrospinal fluid (CSF findings resemble other viral neuroinfections. The purpose of this study is to present some of the most important laboratory findings of our patients with WNND and to evaluate their correlation with fatal outcome.

  7. Detection of West Nile virus lineage 2 in the urine of acute human infections.

    Science.gov (United States)

    Papa, Anna; Testa, Theodolinda; Papadopoulou, Elpida

    2014-12-01

    West Nile virus (WNV) lineage 2 emerged in Greece in 2010 and since then outbreaks in humans have been reported for four consecutive years. Laboratory diagnosis is based mainly on serology. A real-time RT-PCR was applied on urine samples obtained from 35 patients with acute WNV infection. WNV RNA was detected in 40% of the samples with cycle threshold (CT) values ranging from 26.95 to 39.89 (mean 33.11). WNV was isolated from two of four urine samples with low CT (sample shipment and storage conditions are very important for virus detection and isolation. The usefulness of the WNV RNA detection in urine as a diagnostic tool of acute WNV infections is discussed. © 2014 Wiley Periodicals, Inc.

  8. Swine is a possible source of hepatitis E virus infection by comparative study of hepatitis A and E seroprevalence in Thailand.

    Science.gov (United States)

    Sa-nguanmoo, Pattaratida; Posuwan, Nawarat; Vichaiwattana, Preeyaporn; Wutthiratkowit, Norra; Owatanapanich, Somchai; Wasitthankasem, Rujipat; Thongmee, Thanunrat; Poovorawan, Kittiyod; Theamboonlers, Apiradee; Vongpunsawad, Sompong; Poovorawan, Yong

    2015-01-01

    Hepatitis A virus (HAV) and hepatitis E virus (HEV) infection in developing countries are associated with contaminated food or water. Although Thailand is non-endemic for HEV, sporadic infections may occur from zoonotic transmission. Individuals between 7 months to 69 years (mean age = 32.8) from predominantly Islamic Narathiwat (n = 305) and swine farm-dense Lop Buri (n = 416) provinces were screened for anti-HEV and anti-HAV antibodies by commercial enzyme-linked immunosorbent assay and automated chemiluminescent microparticle immunoassay, respectively. Seroprevalence and relative antibody titers were analyzed according to age groups. HAV IgG antibody positive rates in Lop Buri and Narathiwat residents were 39.9% and 58%, respectively (p 50 years old in both provinces possessed anti-HAV IgG. In contrast, seroprevalence for anti-HEV IgG was much higher in Lop Buri (37.3%) than in Narathiwat (8.9%) (p < 0.001). Highest anti-HEV IgG prevalence was found among 21-30 year-olds (50%) in Lop Buri and 41-50 year-olds (14.1%) in Narathiwat. In summary, fewer individuals possessed anti-HEV IgG in Narathiwat where most residents abstained from pork and fewer swine farms are present. Therefore, an increased anti-HEV IgG seroprevalence was associated with the density of swine farm and possibly pork consumption. Adults were more likely than children to have antibodies to both HEV and HAV.

  9. Seroprevalence of human immunodeficiency virus, hepatitis B and C viruses and syphilis infections among blood donors at the Muhimbili National Hospital in Dar Es Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    Lyamuya Eligius F

    2006-01-01

    Full Text Available Abstract Background According to the latest Tanzanian National AIDS Control Programme (NACP report a total of 147,271 individuals donated blood during the year 2002. However, blood safety remains an issue of major concern in transfusion medicine in Tanzania where national blood transfusion services and policies, appropriate infrastructure, trained personnel and financial resources are inadequate. Most of the donated blood is screened for HIV alone. Methods We determined among blood donors at Muhimbili National Hospital (MNH, the seroprevalence of human immunodeficiency virus (HIV, hepatitis C virus (HCV, hepatitis B surface antigen (HBsAg and syphilis by donor type, sex and age and to determine association, if any, in the occurrence of the pathogens. The sample included 1599 consecutive donors, 1424(89.1% males and 175 (10.9% females, who donated blood between April 2004 and May, 2005. Most of them 1125 (70.4% were replacement donors and a few 474 (29.6% voluntary donors. Their age (in years ranged from 16 to 69, and most (72.2% were between 20–39 years. Results Two hundred and fifty four (15.9% of the donated blood had serological evidence of infection with at least one pathogen and 28 (1.8% had multiple infections. The current seroprevalence of HIV, HBsAg, HCV and syphilis among blood donors at MNH in Dar es Salaam was found to be 3.8%, 8.8%, 1.5% and 4.7%, respectively. Respective seroprevalences among HIV seronegative blood donors were 8.7% for HBV, 1.6% for HCV and 4.6% for syphilis. The differences in the prevalence of HIV and syphilis infections between replacement and voluntary donors were statistically significant (P 2 = 58.5 df = 5, P Conclusion The high (15.9% seroprevalence of blood-borne infections in blood donated at MNH calls for routine screening of blood donors for HBV, HCV, HIV and syphilis and for strict selection criteria of donors, with emphasis on getting young voluntary donors and for establishment of strict guidelines

  10. Comparison of assays for the detection of West Nile virus antibodies in equine serum after natural infection or vaccination

    Czech Academy of Sciences Publication Activity Database

    Joó, K.; Bakonyi, T.; Szenci, O.; Ferenczi, E.; Barna, M.; Malik, P.; Hubálek, Zdeněk; Fehér, O.; Kutasi, O.

    2017-01-01

    Roč. 183, č. 1 (2017), s. 1-6 ISSN 0165-2427 Institutional support: RVO:68081766 Keywords : West Nile virus * Haemagglutination-inhibition test * Enzymelinked immunosorbent assay * Plaque reduction neutralization test * Vaccination * Natural infection Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology OBOR OECD: Immunology Impact factor: 1.718, year: 2016

  11. Role of communally nesting ardeid birds in the epidemiology of West Nile virus revisited.

    Science.gov (United States)

    Reisen, William K; Wheeler, Sarah; Armijos, M Veronica; Fang, Ying; Garcia, Sandra; Kelley, Kara; Wright, Stan

    2009-06-01

    Although herons and egrets in the family Ardeidae frequently have been associated with viruses in the Japanese encephalitis virus serocomplex, communal nesting colonies do not appear to be a focus of early season and rapid amplification of West Nile virus (WNV) in California. Evidence for repeated WNV infection was found by testing living and dead nestlings collected under trees with mixed species ardeid colonies nesting above in an oak grove near the University of California arboretum in Davis and in a Eucalyptus grove at a rural farmstead. However, mosquito infection rates at both nesting sites were low and positive pools did not occur earlier than at comparison sites within the City of Davis or at the Yolo Bypass wetlands managed for rice production and waterfowl habitat. Black-crowned night herons (Nycticorax nycticorax) were the most abundant and frequently infected ardeid species, indicating that WNV may be an important cause of mortality among nestlings of this species.

  12. Specific interaction of capsid protein and importin-α/β influences West Nile virus production

    International Nuclear Information System (INIS)

    Bhuvanakantham, Raghavan; Chong, Mun-Keat; Ng, Mah-Lee

    2009-01-01

    West Nile virus (WNV) capsid (C) protein has been shown to enter the nucleus of infected cells. However, the mechanism by which C protein enters the nucleus is unknown. In this study, we have unveiled for the first time that nuclear transport of WNV and Dengue virus C protein is mediated by their direct association with importin-α. This interplay is mediated by the consensus sequences of bipartite nuclear localization signal located between amino acid residues 85-101 together with amino acid residues 42 and 43 of C protein. Elucidation of biological significance of importin-α/C protein interaction demonstrated that the binding efficiency of this association influenced the nuclear entry of C protein and virus production. Collectively, this study illustrated the molecular mechanism by which the C protein of arthropod-borne flavivirus enters the nucleus and showed the importance of importin-α/C protein interaction in the context of flavivirus life-cycle.

  13. Specific interaction of capsid protein and importin-{alpha}/{beta} influences West Nile virus production

    Energy Technology Data Exchange (ETDEWEB)

    Bhuvanakantham, Raghavan; Chong, Mun-Keat [Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597 (Singapore); Ng, Mah-Lee, E-mail: micngml@nus.edu.sg [Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597 (Singapore)

    2009-11-06

    West Nile virus (WNV) capsid (C) protein has been shown to enter the nucleus of infected cells. However, the mechanism by which C protein enters the nucleus is unknown. In this study, we have unveiled for the first time that nuclear transport of WNV and Dengue virus C protein is mediated by their direct association with importin-{alpha}. This interplay is mediated by the consensus sequences of bipartite nuclear localization signal located between amino acid residues 85-101 together with amino acid residues 42 and 43 of C protein. Elucidation of biological significance of importin-{alpha}/C protein interaction demonstrated that the binding efficiency of this association influenced the nuclear entry of C protein and virus production. Collectively, this study illustrated the molecular mechanism by which the C protein of arthropod-borne flavivirus enters the nucleus and showed the importance of importin-{alpha}/C protein interaction in the context of flavivirus life-cycle.

  14. Seroprevalence of Hepatitis B surface antigen, antibodies to the Hepatitis C virus, and human immunodeficiency virus in a hospital-based population in Jaipur, Rajasthan

    Directory of Open Access Journals (Sweden)

    Sood Smita

    2010-01-01

    Full Text Available Background: Hepatitis B, hepatitis C, and HIV infections are a serious global and public health problem. To assess the magnitude and dynamics of disease transmission and for its prevention and control, the study of its seroprevalence is important. A private hospital catering to the needs of a large population represents an important center for serological surveys. Available data, at Rajasthan state level, on the seroprevalence of these bloodborne pathogens is also very limited. Objective: A study was undertaken to estimate the seroprevalence of hepatitis B surface antigen (HBsAg and antibodies to hepatitis C (anti-HCV Ab and human immunodeficiency virus (anti-HIV Ab in both the sexes and different age groups in a hospital-based population in Jaipur, Rajasthan. Materials and Methods: Serum samples collected over a period of 14 months from patients attending OPDs and admitted to various IPDs of Fortis Escorts Hospital, Jaipur, were subjected within the hospital-based lab for the detection of HBsAg and anti-HCV Ab and anti-HIV Ab using rapid card tests. This was followed by further confirmation of all reactive samples by a microparticle enzyme immunoassay (Abbott AxSYM at Super Religare Laboratories (formerly SRL Ranbaxy Reference Lab, Mumbai. Results: The seroprevalence of HBsAg was found to be 0.87%, of anti-HCV Ab as 0.28%, and of anti-HIV Ab as 0.35%. Conclusion: The study throws light on the magnitude of viral transmission in the community in the state of Rajasthan and provides a reference for future studies.

  15. Changes in the seroprevalence of IgG anti-hepatitis A virus between 2001 and 2013: experience at a single center in Korea

    Science.gov (United States)

    Chung, Sung Jun; Kim, Sun Min; Roh, Min; Yu, Mi Yeon; Lee, Jung Hoon; Oh, ChangKyo; Lee, Eun Young; Lee, Seung; Jeon, Yong Cheol; Yoo, Kyo-Sang; Sohn, Joo Hyun

    2014-01-01

    Background/Aims The incidence of symptomatic hepatitis A reportedly increased among 20- to 40-year-old Korean during the late 2000s. Vaccination against hepatitis A was commenced in the late 1990s and was extended to children aged <10 years. In the present study we analyzed the changes in the seroprevalence of IgG anti-hepatitis A virus (HAV) over the past 13 years. Methods Overall, 4903 subjects who visited our hospital between January 2001 and December 2013 were studied. The seroprevalence of IgG anti-HAV was analyzed according to age and sex. In addition, the seroprevalence of IgG anti-HAV was compared among 12 age groups and among the following time periods: early 2000s (2001-2003), mid-to-late 2000s (2006-2008), and early 2010s (2011-2013). The chi-square test for trend was used for statistical analysis. Results The seroprevalence of IgG anti-HAV did not differ significantly between the sexes. Furthermore, compared to the seroprevalence of IgG anti-HAV in the early 2000s and mid-to-late 2000s, that in the early 2010s was markedly increased among individuals aged 1-14 years and decreased among those aged 25-44 years (P<0.01). We also found that the seroprevalence of IgG anti-HAV in individuals aged 25-44 years in the early 2010s was lower than that in the early 2000s and mid-to-late 2000s. Conclusions The number of symptomatic HAV infection cases in Korea is decreasing, but the seroprevalence of IgG anti-HAV is low in the active population. PMID:25032182

  16. Changes in the seroprevalence of IgG anti-hepatitis A virus between 2001 and 2013: experience at a single center in Korea

    Directory of Open Access Journals (Sweden)

    Sung Jun Chung

    2014-06-01

    Full Text Available Background/AimsThe incidence of symptomatic hepatitis A reportedly increased among 20- to 40-year-old Korean during the late 2000s. Vaccination against hepatitis A was commenced in the late 1990s and was extended to children aged <10 years. In the present study we analyzed the changes in the seroprevalence of IgG anti-hepatitis A virus (HAV over the past 13 years.MethodsOverall, 4903 subjects who visited our hospital between January 2001 and December 2013 were studied. The seroprevalence of IgG anti-HAV was analyzed according to age and sex. In addition, the seroprevalence of IgG anti-HAV was compared among 12 age groups and among the following time periods: early 2000s (2001-2003, mid-to-late 2000s (2006-2008, and early 2010s (2011-2013. The chi-square test for trend was used for statistical analysis.ResultsThe seroprevalence of IgG anti-HAV did not differ significantly between the sexes. Furthermore, compared to the seroprevalence of IgG anti-HAV in the early 2000s and mid-to-late 2000s, that in the early 2010s was markedly increased among individuals aged 1-14 years and decreased among those aged 25-44 years (P<0.01. We also found that the seroprevalence of IgG anti-HAV in individuals aged 25-44 years in the early 2010s was lower than that in the early 2000s and mid-to-late 2000s.ConclusionsThe number of symptomatic HAV infection cases in Korea is decreasing, but the seroprevalence of IgG anti-HAV is low in the active population.

  17. Factors That Influence the Transmission of West Nile Virus in Florida.

    Science.gov (United States)

    Day, Jonathan F; Tabachnick, Walter J; Smartt, Chelsea T

    2015-09-01

    West Nile virus (WNV) was first detected in North America in New York City during the late summer of 1999 and was first detected in Florida in 2001. Although WNV has been responsible for widespread and extensive epidemics in human populations and epizootics in domestic animals and wildlife throughout North America, comparable epidemics have never materialized in Florida. Here, we review some of the reasons why WNV has yet to cause an extensive outbreak in Florida. The primary vector of mosquito-borne encephalitis virus in Florida is Culex nigripalpus Theobald. Rainfall, drought, and temperature are the primary factors that regulate annual populations of this species. Cx. nigripalpus is a competent vector of WNV, St. Louis encephalitis virus, and eastern equine encephalitis virus in Florida, and populations of this species can support focal amplification and transmission of these arboviruses. We propose that a combination of environmental factors influencing Cx. nigripalpus oviposition, blood-feeding behavior, and vector competence have limited WNV transmission in Florida to relatively small focal outbreaks and kept the state free of a major epidemic. Florida must remain vigilant to the danger from WNV, because a change in these environmental factors could easily result in a substantial WNV epidemic rivaling those seen elsewhere in the United States. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Antiviral Properties of the Natural Polyphenols Delphinidin and Epigallocatechin Gallate against the Flaviviruses West Nile Virus, Zika Virus, and Dengue Virus

    Directory of Open Access Journals (Sweden)

    Ángela Vázquez-Calvo

    2017-07-01

    Full Text Available The Flavivirus genus contains important pathogens, such as West Nile virus (WNV, Zika virus (ZIKV, and Dengue virus (DENV, which are enveloped plus-strand RNA viruses transmitted by mosquitoes and constitute a worrisome threat to global human and animal health. Currently no licensed drugs against them are available, being, thus, still necessary the search for effective antiviral molecules. In this line, a novel antiviral approach (economical, simple to use, and environmental friendly is the use of natural compounds. Consequently, we have tested the antiviral potential of different polyphenols present in plants and natural products, such as wine and tea, against WNV, ZIKV, and DENV. So that, we assayed the effect of a panel of structurally related polyphenols [delphinidin (D, cyanidin (Cy, catechin (C, epicatechin (EC, epigallocatechin (EGC, and epigallocatechin gallate (EGCG] on WNV infection, and found that D and EGCG inhibited more effectively the virus production. Further analysis with both compounds indicated that they mainly affected the attachment and entry steps of the virus life cycle. Moreover, D and EGCG showed a direct effect on WNV particles exerting a virucidal effect. We showed a similar inhibition of viral production of these compounds on WNV variants that differed on acidic pH requirements for viral fusion, indicating that their antiviral activity against WNV is produced by a virucidal effect rather than by an inhibition of pH-dependent viral fusion. Both polyphenols also reduced the infectivity of ZIKV and DENV. Therefore, D and EGCG impair the infectivity in cell culture of these three medically relevant flaviviruses.

  19. Culex quinquefasciatus (Diptera: Culicidae) as a potential West Nile virus vector in Tucson, Arizona: Blood meal analysis indicates feeding on both humans and birds

    OpenAIRE

    Zinser, Margaret; Ramberg, Frank; Willott, Elizabeth

    2004-01-01

    Most reports from the United States suggest Culex quinquefasciatus mosquitoes feed minimally on humans. Given the abundance of C. quinquefasciatus in residential Tucson and parts of metropolitan Phoenix, and the arrival of West Nile virus to this area, discovering the blood meal hosts of the local population is important. Using a sandwich ELISA technique, the local C. quinquefasciatus were found to feed on both humans and birds. This suggests they should be considered potential West Nile viru...

  20. Chimeric vaccine composed of viral peptide and mammalian heat-shock protein 60 peptide protects against West Nile virus challenge.

    Science.gov (United States)

    Gershoni-Yahalom, Orly; Landes, Shimon; Kleiman-Shoval, Smadar; Ben-Nathan, David; Kam, Michal; Lachmi, Bat-El; Khinich, Yevgeny; Simanov, Michael; Samina, Itzhak; Eitan, Anat; Cohen, Irun R; Rager-Zisman, Bracha; Porgador, Angel

    2010-08-01

    The protective efficacy and immunogenicity of a chimeric peptide against West Nile virus (WNV) was evaluated. This virus is the aetiological agent of West Nile fever, which has recently emerged in the western hemisphere. The rapid spread of WNV throughout North America, as well as the constantly changing epidemiology and transmission of the virus by blood transfusion and transplantation, have raised major public-health concerns. Currently, there are no effective treatments for WNV or vaccine for human use. We previously identified a novel, continuous B-cell epitope from domain III of the WNV envelope protein, termed Ep15. To test whether this epitope can protect against WNV infection, we synthesized a linear chimeric peptide composed of Ep15 and the heat-shock protein 60 peptide, p458. The p458 peptide is an effective carrier peptide for subunit vaccines against other infectious agents. We now report that mice immunized with the chimeric peptide, p458-Ep15, were resistant to lethal challenges with three different WNV strains. Moreover, their brains were free of viral genome and infectious virus. Mice immunized with Ep15 alone or with p431-Ep15, a control conjugate, were not protected. The chimeric p458-Ep15 peptide induced WNV-specific immunoglobulin G antibodies that neutralized the virus and induced the secretion of interferon-gammain vitro. Challenge of chimeric peptide-immunized mice considerably enhanced WNV-specific neutralizing antibodies. We conclude that this chimeric peptide can be used for formulation of a human vaccine against WNV.

  1. Noncoding Subgenomic Flavivirus RNA Is Processed by the Mosquito RNA Interference Machinery and Determines West Nile Virus Transmission by Culex pipiens Mosquitoes.

    Science.gov (United States)

    Göertz, G P; Fros, J J; Miesen, P; Vogels, C B F; van der Bent, M L; Geertsema, C; Koenraadt, C J M; van Rij, R P; van Oers, M M; Pijlman, G P

    2016-11-15

    Flaviviruses, such as Zika virus, yellow fever virus, dengue virus, and West Nile virus (WNV), are a serious concern for human health. Flaviviruses produce an abundant noncoding subgenomic flavivirus RNA (sfRNA) in infected cells. sfRNA results from stalling of the host 5'-3' exoribonuclease XRN1/Pacman on conserved RNA structures in the 3' untranslated region (UTR) of the viral genomic RNA. sfRNA production is conserved in insect-specific, mosquito-borne, and tick-borne flaviviruses and flaviviruses with no known vector, suggesting a pivotal role for sfRNA in the flavivirus life cycle. Here, we investigated the function of sfRNA during WNV infection of Culex pipiens mosquitoes and evaluated its role in determining vector competence. An sfRNA1-deficient WNV was generated that displayed growth kinetics similar to those of wild-type WNV in both RNA interference (RNAi)-competent and -compromised mosquito cell lines. Small-RNA deep sequencing of WNV-infected mosquitoes indicated an active small interfering RNA (siRNA)-based antiviral response for both the wild-type and sfRNA1-deficient viruses. Additionally, we provide the first evidence that sfRNA is an RNAi substrate in vivo Two reproducible small-RNA hot spots within the 3' UTR/sfRNA of the wild-type virus mapped to RNA stem-loops SL-III and 3' SL, which stick out of the three-dimensional (3D) sfRNA structure model. Importantly, we demonstrate that sfRNA-deficient WNV displays significantly decreased infection and transmission rates in vivo when administered via the blood meal. Finally, we show that transmission and infection rates are not affected by sfRNA after intrathoracic injection, thereby identifying sfRNA as a key driver to overcome the mosquito midgut infection barrier. This is the first report to describe a key biological function of sfRNA for flavivirus infection of the arthropod vector, providing an explanation for the strict conservation of sfRNA production. Understanding the flavivirus transmission

  2. A VLP-based vaccine targeting domain III of the West Nile virus e protein protects from lethal infection in mice

    NARCIS (Netherlands)

    G. Spohn (Gunther); G.T. Jennings (Gary); B.E.E. Martina (Byron); I. Keller (Iris); M. Beck (Markus); P. Pumpens (Paul); A.D.M.E. Osterhaus (Albert); M.F. Bachmann (Martin)

    2010-01-01

    textabstractBackground. Since its first appearance in the USA in 1999, West Nile virus (WNV) has spread in the Western hemisphere and continues to represent an important public health concern. In the absence of effective treatment, there is a medical need for the development of a safe and efficient

  3. Host genetic risk factors for West Nile virus infection and disease progression.

    Directory of Open Access Journals (Sweden)

    Abigail W Bigham

    Full Text Available West Nile virus (WNV, a category B pathogen endemic in parts of Africa, Asia and Europe, emerged in North America in 1999, and spread rapidly across the continental U.S. Outcomes of infection with WNV range from asymptomatic to severe neuroinvasive disease manifested as encephalitis, paralysis, and/or death. Neuroinvasive WNV disease occurs in less than one percent of cases, and although host genetic factors are thought to influence risk for symptomatic disease, the identity of these factors remains largely unknown. We tested 360 common haplotype tagging and/or functional SNPs in 86 genes that encode key regulators of immune function in 753 individuals infected with WNV including: 422 symptomatic WNV cases and 331 cases with asymptomatic infections. After applying a Bonferroni correction for multiple tests and controlling for population stratification, SNPs in IRF3 (OR 0.54, p = 0.035 and MX1, (OR 0.19, p = 0.014 were associated with symptomatic WNV infection and a single SNP in OAS1 (OR 9.79, p = 0.003 was associated with increased risk for West Nile encephalitis and paralysis (WNE/P. Together, these results suggest that genetic variation in the interferon response pathway is associated with both risk for symptomatic WNV infection and WNV disease progression.

  4. Estimation of hepatitis E virus (HEV) pig seroprevalence using Elisa and Western blot and comparison between human and pig HEV sequences in Belgium.

    NARCIS (Netherlands)

    Thiry, D.; Mauroy, A.; Saegerman, C.; Thomas, I.; Wautier, M.; Miry, C.; Czaplicki, G.; Berkvens, D.; Praet, N.; Poel, van der W.H.M.; Cariolet, R.; Brochier, B.; Thiry, E.

    2014-01-01

    Zoonotic transmission of hepatitis E virus (HEV) is of special concern, particularly in high income countries were waterborne infections are less frequent than in developing countries. High HEV seroprevalences can be found in European pig populations. The aims of this study were to obtain prevalence

  5. Búsqueda de flavivirus en mosquitos de humedales españoles: análisis moleculares del virus west nile y otros flavivirus

    OpenAIRE

    Vázquez González, Ana

    2011-01-01

    Teniendo en cuenta la importancia de los flavivirus en salud humana, la gran actividad y expansión del virus West Nile en los últimos años y los antecedentes serológicos que evidencian la presencia de estos virus en nuestro país, esta tesis doctoral se ha basado en el estudio de la presencia de estos virus, en su caracterización molecular y filogenética y en el desarrollo de nueva metodología para su diagnóstico. Por ello nos planteamos tres objetivos principales. En primer lug...

  6. West Nile Virus lineage-2 in Culex specimens from Iran.

    Science.gov (United States)

    Shahhosseini, Nariman; Chinikar, Sadegh; Moosa-Kazemi, Seyed Hassan; Sedaghat, Mohammad Mehdi; Kayedi, Mohammad Hassan; Lühken, Renke; Schmidt-Chanasit, Jonas

    2017-10-01

    Screening of mosquitoes for viruses is an important forecasting tool for emerging and re-emerging arboviruses. Iran has been known to harbour medically important arboviruses such as West Nile virus (WNV) and dengue virus (DENV) based on seroepidemiological data. However, there are no data about the potential mosquito vectors for arboviruses in Iran. This study was performed to provide mosquito and arbovirus data from Iran. A total of 32 317 mosquitos were collected at 16 sites in five provinces of Iran in 2015 and 2016. RT-PCR for detection of flaviviruses was performed. The PCR amplicons were sequenced, and 109 WNV sequences, including one obtained in this study, were used for phylogenetic analyses. The 32 317 mosquito specimens belonging to 25 species were morphologically distinguished and distributed into 1222 pools. Culex pipiens s.l. comprised 56.429%. One mosquito pool (0.08%), containing 46 unfed Cx. pipiens pipiens form pipiens (Cpp) captured in August 2015, was positive for flavivirus RNA. Subsequent sequencing and phylogenetic analyses revealed that the detected Iranian WNV strain belongs to lineage 2 and clusters with a strain recently detected in humans. No flaviviruses other than WNV were detected in the mosquito pools. Cpp could be a vector for WNV in Iran. Our findings indicate recent circulation of WNV lineage-2 strain in Iran and provide a solid base for more targeted arbovirus surveillance programs. © 2017 John Wiley & Sons Ltd.

  7. Transmission dynamics and changing epidemiology of West Nile virus.

    Science.gov (United States)

    Blitvich, Bradley J

    2008-06-01

    West Nile virus (WNV) is a flavivirus that is maintained in a bird-mosquito transmission cycle. Humans, horses and other non-avian vertebrates are usually incidental hosts, but evidence is accumulating that this might not always be the case. Historically, WNV has been associated with asymptomatic infections and sporadic disease outbreaks in humans and horses in Africa, Europe, Asia and Australia. However, since 1994, the virus has caused frequent outbreaks of severe neuroinvasive disease in humans and horses in Europe and the Mediterranean Basin. In 1999, WNV underwent a dramatic expansion of its geographic range, and was reported for the first time in the Western Hemisphere during an outbreak of human and equine encephalitis in New York City. The outbreak was accompanied by extensive and unprecedented avian mortality. Since then, WNV has dispersed across the Western Hemisphere and is now found throughout the USA, Canada, Mexico and the Caribbean, and parts of Central and South America. WNV has been responsible for >27,000 human cases, >25,000 equine cases and hundreds of thousands of avian deaths in the USA but, surprisingly, there have been only sparse reports of WNV disease in vertebrates in the Caribbean and Latin America. This review summarizes our current understanding of WNV with particular emphasis on its transmission dynamics and changing epidemiology.

  8. Culex pipiens, an experimental efficient vector of West Nile and Rift Valley fever viruses in the Maghreb region.

    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.

  9. Cross-sectional seroprevalence of antibodies against 6, 11, 16 and 18 human papilloma virus (HPV types among teenagers and young women in Italy

    Directory of Open Access Journals (Sweden)

    Silvia Lupi

    2014-06-01

    Full Text Available BACKGROUND. Little is known about human papilloma virus (HPV seroprevalence in the healthy Italian population. The aim of the study was to assess seroprevalence of antibodies against HPV 6, 11, 16 and 18 among girls and young women in Italy. METHODS. Sera were tested with a commercially available ELISA assay detecting specific IgG. Results. Seroprevalence was 54.1% in girls between 11 to 18 years old and 8.2% in over 18s. Overall seropositivity in birth cohorts invited for free immunization reached 72.8% and was significantly higher than in other age subgroups. The highest levels of antibodies were detected in girls of 12 years old that should have just completed the vaccination schedule. Conclusion. A standardized seroepidemiological survey on HPV represents a useful tool for identifying groups at risk in which immunization is recommended, monitoring of vaccinated women, assessing whether booster vaccination is required.

  10. Seroprevalence of hepatitis C, hepatitis B and HIV viruses in hemophiliacs born 1985-2010 in west Azarbaijan of Iran

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    Nasim Valizadeh

    2013-01-01

    Full Text Available Background: Although, in the past the risk of transfusion transmitted viral infections were high in hemophilia patients, but introduction of viral inactivation methods in1985,decreased the risk of human immunodeficiency and hepatitis C and B viruses transmission significantly. The aim of study was seroprevalence of hepatitis B surface antigen (HBs Ag, hepatitis C virus antibody (HCV Ab and human immunodeficiency virus antibody (HIVAb in hemophiliacs in west Azarbaijan of Iran, born in 1985-2010. Materials and Methods: In a cross-sectional study, fifty patients with hereditary bleeding disorders born in 1985-2010, from total 250 patients who had been registered in Urmia Hemophilia Society were enrolled through the year 2010 to assess their seroprevalence for HCV Ab, HIV Ab and HBs Ag. Thirty five of 50 patients had hemophilia. Also; we performed a subset analysis for hemophilia patients. Results: All 50 patients with hereditary bleeding disorders including 35 patients with hemophilia were seronegative for HIV Ab and HBs Ag. HCV-Ab was detected in serum of 3 of 50 (6% patients with bleeding disorders. After subset analysis for hemophilia (A and B patients, we found HCV infection in 8.57% (3 of 35 of hemophiliacs. Conclusion: In this study prevalence of HCV infection was very smaller than similar studies in Iran and other countries. This study shows the safety of using viral inactivated factor concentrates and recombinant factors after year 1985.None of Hemophiliacs were seropositive for HIV Ab and HBs Ag.

  11. Serosurveillance for Japanese encephalitis and West Nile viruses in resident birds in Hawai'i.

    Science.gov (United States)

    Nemeth, Nicole M; Bosco-Lauth, Angela M; Sciulli, Rebecca H; Gose, Remedios B; Nagata, Mark T; Bowen, Richard A

    2010-04-01

    Japanese encephalitis virus (JEV) and West Nile virus (WNV) are emerging zoonotic arboviruses that have recently undergone intercontinental expansion. Both JEV and WNV are naturally transmitted between mosquito vectors and vertebrate reservoir hosts, including birds. A potential route of JEV introduction from Asia to western North America is via the Hawaiian archipelago, while the spread of WNV from mainland North America to Hawai'i is also considered an impending threat. We surveyed resident, non-native bird sera for antibodies to JEV and WNV on two Hawaiian Islands from 2004-2005. Three of 1,835 birds (0.16%) had evidence of antiflavivirus antibodies, demonstrating neutralizing activity to JEV and St. Louis encephalitis virus (SLEV). These detections could represent a limited transmission focus of either, or both, JEV and SLEV, or cross-reactive antibodies due to primary infection with an alternate flavivirus. Frequent air traffic from both Asia and North America to Hawai'i, along with the presence of probable competent vectors and amplifying vertebrate hosts in Hawai'i, increases the likelihood of introduction and maintenance of novel flaviviruses. Therefore, it is important to monitor for the presence of these viruses.

  12. SEROPREVALENCE OF ANTIBODIES TO HEPATITIS A VIRUS IN BLOODDONORS AND PATIENTS IN UNIVERSITY CLINICAL CENTER MARIBOR

    Directory of Open Access Journals (Sweden)

    Božislava Majcen Vivod

    2008-04-01

    Seroprevalence of anti-HAV antibodies declined in last decades in European countries. Inour study 20 % blood donors had antibodies anti-HAV in the group younger than 35 yearsand among patient only 15 % of patients had antibodies in the same group.The use of a vaccine against hepatitis A virus has to be considered for the prevention ofsymptomatic hepatitis, especially in adults at risk for infection, such as those who travel toareas with poor sanitation. Furthermore, they should take into consideration the fact thatthe severity of the disease increases with age

  13. 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

  14. Clinical evaluation and outcomes of naturally acquired West Nile virus infection in raptors.

    Science.gov (United States)

    Nemeth, Nicole M; Kratz, Gail E; Bates, Rebecca; Scherpelz, Judy A; Bowen, Richard A; Komar, Nicholas

    2009-03-01

    West Nile virus (WNV) infection and associated disease and mortality have been documented in numerous North American raptor species. Information regarding clinical presentations and long-term outcomes of WNV-infected raptors is important in the clinic for the diagnosis, treatment, and assessment of prognosis, as well as for understanding potential population level effects on raptor species. Raptors of 22 species admitted to a rehabilitation clinic were tested, from 2002 to 2005, for previous and acute WNV infection, while comparing clinical syndromes, trauma, and rehabilitation outcomes. Forty-two percent of admitted raptors (132/314) had been infected with WNV, and these presented with a WNV-attributed clinical disease rate of 67.4% (89/132). West Nile virus-infected raptors were less likely to be released (79/132 [59.8%]) than negative raptors (138/182 [75.8%]) and more likely to die or be euthanized (47/132 [35.6%] for WNV-infected vs. 32/182 [17.6%] for WNV-negative). However, WNV-infected raptors with neurologic disease were no less likely to be released (29/53 [54.7%]) than those without neurologic disease (50/79 [63.3%]). Clinical WNV-associated syndromes varied among species. Great horned owls (Bubo virginianus) were more likely to have neurologic signs, whereas American kestrels (Falco sparverius) and Swainson's hawks (Buteo swainsonii) were less likely to have neurologic signs. These results suggest that free-ranging raptors are frequently infected with WNV and that clinical syndromes differ among species. WNV has potentially devastating effects on raptors; however, rehabilitation of WNV-infected raptors can lead to positive outcomes, even for those having had severe neurologic disease.

  15. Seroprevalence of feline leukemia virus, feline immunodeficiency virus and heartworm infection among owned cats in tropical Mexico.

    Science.gov (United States)

    Ortega-Pacheco, Antonio; Aguilar-Caballero, Armando J; Colin-Flores, Rafael F; Acosta-Viana, Karla Y; Guzman-Marin, Eugenia; Jimenez-Coello, Matilde

    2014-06-01

    Several infectious agents may be distributed within a healthy population of cats where diverse risk factors predispose them to come into contact with pathogens. Blood samples from 227 owned cats in Merida, Mexico, were collected with the objective of determining the seroprevalence and associated risk factors of feline leukemia virus (FeLV) and Dirofilaria immitis antigen, and feline immunodeficiency virus (FIV) antibody. Serological detection of FeLV and D immitis antigens, and FIV antibodies was performed using the commercial kit SNAP Feline Triple Test. The prevalence was found to be 7.5% for FeLV, 2.5% for FIV and 0% for D immitis. Adult cats were at a higher risk of coming into contact with FeLV (P <0.01) than younger cats. Owing to its low prevalence, a risk factor analysis was not performed for FIV. The prevalence of retroviral infections found in this study was low, but within the limits reported in the different geographical areas of the world. Cases of filariosis in the domestic cats of Merida, Mexico, may be absent or very low; however, the low sample size may have influenced these results. © ISFM and AAFP 2013.

  16. The effect of West Nile virus perceptions and knowledge on protective behavior and mosquito breeding in residential yards in Upstate New York

    NARCIS (Netherlands)

    Tuiten, W.; Koenraadt, C.J.M.; McComas, K.; Harrington, L.C.

    2009-01-01

    A knowledge, attitudes, and practices (KAP) questionnaire combined with entomological surveys of residential mosquito-breeding sites were conducted in two Upstate New York neighborhoods. We tested the hypothesis that “correct” West Nile virus (WNV) knowledge and perceptions correspond with the use

  17. Seroprevalence of Human Immunodeficiency Virus, Hepatitis B ...

    African Journals Online (AJOL)

    Methods: A retrospective analysis of consecutive blood donors' records covering the period between January 2010 and December 2014 was conducted to analyze for seroprevalence of HIV, HBV, HCV and syphilis among blood donors aged 17-65 years. The association of these infections with age group, blood group, their ...

  18. Equine Immunoglobulin and Equine Neutralizing F(ab')₂ Protect Mice from West Nile Virus Infection.

    Science.gov (United States)

    Cui, Jiannan; Zhao, Yongkun; Wang, Hualei; Qiu, Boning; Cao, Zengguo; Li, Qian; Zhang, Yanbo; Yan, Feihu; Jin, Hongli; Wang, Tiecheng; Sun, Weiyang; Feng, Na; Gao, Yuwei; Sun, Jing; Wang, Yanqun; Perlman, Stanley; Zhao, Jincun; Yang, Songtao; Xia, Xianzhu

    2016-12-18

    West Nile virus (WNV) is prevalent in Africa, Europe, the Middle East, West Asia, and North America, and causes epidemic encephalitis. To date, no effective therapy for WNV infection has been developed; therefore, there is urgent need to find an efficient method to prevent WNV disease. In this study, we prepared and evaluated the protective efficacy of immune serum IgG and pepsin-digested F(ab')₂ fragments from horses immunized with the WNV virus-like particles (VLP) expressing the WNV M and E proteins. Immune equine F(ab')₂ fragments and immune horse sera efficiently neutralized WNV infection in tissue culture. The passive transfer of equine immune antibodies significantly accelerated the virus clearance in the spleens and brains of WNV infected mice, and reduced mortality. Thus, equine immunoglobulin or equine neutralizing F(ab')₂ passive immunotherapy is a potential strategy for the prophylactic or therapeutic treatment of patients infected with WNV.

  19. Equine Immunoglobulin and Equine Neutralizing F(ab′2 Protect Mice from West Nile Virus Infection

    Directory of Open Access Journals (Sweden)

    Jiannan Cui

    2016-12-01

    Full Text Available West Nile virus (WNV is prevalent in Africa, Europe, the Middle East, West Asia, and North America, and causes epidemic encephalitis. To date, no effective therapy for WNV infection has been developed; therefore, there is urgent need to find an efficient method to prevent WNV disease. In this study, we prepared and evaluated the protective efficacy of immune serum IgG and pepsin-digested F(ab′2 fragments from horses immunized with the WNV virus-like particles (VLP expressing the WNV M and E proteins. Immune equine F(ab′2 fragments and immune horse sera efficiently neutralized WNV infection in tissue culture. The passive transfer of equine immune antibodies significantly accelerated the virus clearance in the spleens and brains of WNV infected mice, and reduced mortality. Thus, equine immunoglobulin or equine neutralizing F(ab′2 passive immunotherapy is a potential strategy for the prophylactic or therapeutic treatment of patients infected with WNV.

  20. Seroprevalence and risk factors of herpes simplex virus type-2 infection among pregnant women in Northeast India

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    Biswas Dipankar

    2011-11-01

    Full Text Available Abstract Background Herpes simplex virus type-2 (HSV-2 is one of the most common sexually transmitted infections that facilitate human immunodeficiency virus (HIV acquisition by over two fold or more. The development of HSV-2 control methods as a measure to control HIV epidemic in high HSV-2/HIV areas has become a priority. Two out of the six high HIV prevalent states of India are located in the Northeastern region of India. Due to lack of documented HSV-2 studies from this part of the country; there was a need for estimating the seroprevalence and risk factors of HSV-2 infection in this defined population. Methods Pregnant women (n = 1640 aged18 years and above attending antenatal clinics of tertiary referral hospitals in five Northeastern states of India were screened for type specific HSV-2 IgG antibodies. Blood samples were collected from all the participants after conducting interviews. Univariate and multivariate analyses were performed to identify the risk factors associated with HSV-2 seropositivity. Results Overall seroprevalence of HSV-2 infection was 8.7% (142/1640; 95% CI 7.3-10.0 with a highest prevalence of 15.0% (46/307; 95% CI 11.0-19.0 in the state of Arunachal Pradesh. Higher seroprevalence was observed with increasing age (Adj. Odds Ratio [AOR] 1.9 for 22-25 years old, AOR 2.29 for > 29 years old. The risk factors associated with HSV-2 seropositives were multiple sex partners (AOR 2.5, p = 0.04, condom non-user's (AOR 4.7, p 0.001, early coitarchal age (age of first intercourse 'less than 18 years' (AOR 9.6, p = 0.04, middle income group (AOR 2.1, p = 0.001 compared to low income group and low level of education (AOR 3.7, p = 0.02 compared to higher education. HSV-2 seropositivity was higher among Christians (12.6% compared to Muslims (3.8%. The most frequent clinical symptoms among HSV-2 seropositives were excess vaginal discharge in last one year (53.5%, 76/142 and pelvic pain (26.1%, 37/142. While among subjects with

  1. Phylogenetic analysis of West Nile virus isolated in Italy in 2008.

    Science.gov (United States)

    Savini, G; Monaco, F; Calistri, P; Lelli, R

    2008-11-27

    In Italy the first occurrence of West Nile virus (WNV) infection was reported in Tuscany region during the late summer of 1998. In August 2008, the WNV infection re-emerged in Italy, in areas surrounding the Po river delta, and involving three regions Lombardy, Emilia Romagna and Veneto. WNV was isolated from blood and organs samples of one horse, one donkey, one pigeon (Columba livia) and three magpies (Pica pica). The phylogenetic analysis of the isolates, conducted on 255 bp in the region coding for the E protein, indicates that these isolates belong to the lineage I among the European strains. According to the analysis, both the 1998 and 2008 Italian strains as well as isolates from Romania, Russia, Senegal and Kenya fell in the same sub-cluster.

  2. Experimental transmission of West Nile Virus and Rift Valley Fever Virus by Culex pipiens from Lebanon.

    Directory of Open Access Journals (Sweden)

    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.

  3. Seroprevalence of HTLV -I/II amongst Blood Donors in Osogbo ...

    African Journals Online (AJOL)

    Background: HTLV type I/II is a blood borne infection that can be transmitted via blood transfusion. Objective: To determine the seroprevalence of human T – lymphotropic virus among blood donors in Osogbo, Nigeria. Methods: Diagnosis of Human T. Lymphotropic virus antigen was carried out on 372 serum samples ...

  4. Comparison of hepatitis E virus seroprevalence between HBsAg-positive population and healthy controls in Shandong province, China.

    Science.gov (United States)

    Zhang, Li; Jiang, Zechun; Lv, Jingjing; Liu, Jiaye; Yan, Bingyu; Feng, Yi; Li, Li; Zhang, Guomin; Wang, Fuzhen; Xu, Aiqiang

    2018-02-12

    Persons with chronic hepatitis B (CHB) infection were reported to suffer severe disease after hepatitis E virus (HEV) superinfection, but the studies regarding HEV seroprevalence in this population were limited. A recent study in Vietnam found higher HEV seroprevalence among CHB patients compared with healthy controls. A community-based case-control study was conducted in two counties of Shandong province, China, where hepatitis E incidence was at the highest (Rushan) and lowest (Zhangqiu) in the province based on data from routine public health surveillance. Four townships were selected randomly from each county and all residents in these townships were tested for hepatitis B surface antigen (HBsAg). Those tested positive for HBsAg (CHB group) and the 1:1 age and sex-matched HBsAg-negative residents (control group) were included. Anti-HEV IgM and IgG were tested and positive rates of IgG and IgM were compared between the CHB group and the control group. In total, 2048 CHB participants and 2054 controls were included in the study. In the CHB group, HEV IgG seroprevalence was 9.16% (95% CI: 7.47-11.09) in Zhangqiue and 38.06% (95% CI: 35.07-41.19) in Rushan (P < 0.001); the corresponding rates of IgM were 0.1% (95% CI: 0.002-0.54) and 1.57% (95% CI: 0.90-2.53), respectively (P < 0.001). HEV IgG seroprevalence was similar between CHB group and the control group in both counties (P = 0.21, P = 0.47, respectively) and the same results were found for the positive rate of IgM (P = 0.103, P = 0.262, respectively). Multivariable analysis showed the status of HBsAg was not independently associated with the status of anti-HEV IgG in either Zhangqiu or Rushan [P = 0.187, OR = 1.23(95% CI: 0.90, 1.68); P = 0.609, OR = 1.05 (95% CI: 0.87, 1.26)]. The seroprevalence of HEV varies greatly in different geographic areas, but the seroprevalence is similar between populations with and without CHB. CHB patients residing in high HEV endemic areas

  5. Entomologic and avian investigations of an epidemic of West Nile fever in Romania in 1996, with serologic and molecular characterization of a virus isolate from mosquitoes.

    Science.gov (United States)

    Savage, H M; Ceianu, C; Nicolescu, G; Karabatsos, N; Lanciotti, R; Vladimirescu, A; Laiv, L; Ungureanu, A; Romanca, C; Tsai, T F

    1999-10-01

    Between July and October 1996, a West Nile (WN) fever epidemic occurred in the southern plain and Danube Valley of Romania and in the capital city of Bucharest, resulting in hundreds of neurologic cases and 17 fatalities. In early October 1996, entomologic and avian investigations of the epidemic were conducted in the city of Bucharest and nearby rural areas. Thirty (41%) of 73 domestic fowl sampled had neutralizing antibody to WN virus, including 5 of 13 ducks (38%), 1 of 1 goose, 19 of 52 chickens (37%), 1 of 1 peahen, and 4 of 6 turkeys (67%). Seroprevalence in domestic fowl (27%, or 7 of 26) from the urban Bucharest site was not significantly different (P = 0.08, by Fisher's exact test) than rates at three rural sites (50%, or 23 of 46). Serum collected from one of 12 Passeriformes, an Erithacus rubecula, was positive for neutralizing antibody to WN virus. A total of 5,577 mosquitoes representing seven taxa were collected. Culex pipiens pipiens accounted for 96% of the mosquitoes collected. A single virus isolate, RO97-50, was obtained from a pool of 30 Cx. p. pipiens females aspirated from the walls and ceiling of a blockhouse located near the center of Bucharest, resulting in a minimum infection rate of 0.19 per 1,000. Antisera prepared against RO97-50 failed to distinguish among RO97-50, WN virus strain Eg101, and Kunjin (KUN) virus strain MRM16. A 2,323-basepair DNA fragment of the envelope (E) glycoprotein gene from RO97-50 and a Romanian WN virus strain obtained from a human cerebrospinal fluid sample, RO96-1030, were sequenced. Phylogenetic analyses of 23 WN virus strains and one KUN virus strain using the amino acid and nucleotide sequences for a small portion of the E gene suggest the existence of two large lineages of viruses. Bootstrap analysis of the nucleotide alignment indicated strong support (95%) for a lineage composed of WN virus strains from northern Africa, including isolates from Egypt and Algeria, and west, central, and east Africa, all of

  6. Seroprevalences to viral pathogens in free-ranging and captive cheetahs (Acinonyx jubatus) on Namibian Farmland.

    Science.gov (United States)

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-02-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts.

  7. Seroprevalences to Viral Pathogens in Free-Ranging and Captive Cheetahs (Acinonyx jubatus) on Namibian Farmland▿

    Science.gov (United States)

    Thalwitzer, Susanne; Wachter, Bettina; Robert, Nadia; Wibbelt, Gudrun; Müller, Thomas; Lonzer, Johann; Meli, Marina L.; Bay, Gert; Hofer, Heribert; Lutz, Hans

    2010-01-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline coronavirus, canine distemper virus, feline immunodeficiency virus [FIV], puma lentivirus, feline leukemia virus, and rabies virus) in 68 free-ranging cheetahs on east-central Namibian farmland, 24 nonvaccinated Namibian captive cheetahs, and several other wild carnivore species and conducted necropsies of cheetahs and other wild carnivores. Eight of 11 other wild carnivores were seropositive for at least one of the viruses, including the first record of an FIV-like infection in a wild felid west of the Kalahari, the caracal (Felis caracal). Seroprevalences of the free-ranging cheetahs were below 5% for all nine viruses, which is significantly lower than seroprevalences in nonvaccinated captive cheetahs and those for five of seven viruses in previously studied free-ranging cheetahs from north-central Namibia (L. Munson, L. Marker, E. Dubovi, J. A. Spencer, J. F. Evermann, and S. J. O'Brien, J. Wildl. Dis. 40:23-31, 2004). There was no clinical or pathological evidence of infectious diseases in living or dead cheetahs. The results suggest that while free-ranging wild carnivores may be a source of pathogens, the distribution of seroprevalences across studies mirrored local human population density and factors associated with human habitation, probably reflecting contact opportunities with (nonvaccinated) domestic and feral cats and dogs. They also suggest that Namibian cheetahs respond effectively to viral challenges, encouraging consistent and sustainable conservation efforts

  8. Seroprevalence and risk factors of herpes simplex virus type-2 infection among pregnant women in Northeast India.

    Science.gov (United States)

    Biswas, Dipankar; Borkakoty, Biswajyoti; Mahanta, Jagadish; Walia, Kamini; Saikia, Lahari; Akoijam, Brogen S; Jampa, Lobsang; Kharkongar, Alia; Zomawia, Eric

    2011-11-23

    Herpes simplex virus type-2 (HSV-2) is one of the most common sexually transmitted infections that facilitate human immunodeficiency virus (HIV) acquisition by over two fold or more. The development of HSV-2 control methods as a measure to control HIV epidemic in high HSV-2/HIV areas has become a priority. Two out of the six high HIV prevalent states of India are located in the Northeastern region of India. Due to lack of documented HSV-2 studies from this part of the country; there was a need for estimating the seroprevalence and risk factors of HSV-2 infection in this defined population. Pregnant women (n = 1640) aged18 years and above attending antenatal clinics of tertiary referral hospitals in five Northeastern states of India were screened for type specific HSV-2 IgG antibodies. Blood samples were collected from all the participants after conducting interviews. Univariate and multivariate analyses were performed to identify the risk factors associated with HSV-2 seropositivity. Overall seroprevalence of HSV-2 infection was 8.7% (142/1640; 95% CI 7.3-10.0) with a highest prevalence of 15.0% (46/307; 95% CI 11.0-19.0) in the state of Arunachal Pradesh. Higher seroprevalence was observed with increasing age (Adj. Odds Ratio [AOR] 1.9 for 22-25 years old, AOR 2.29 for > 29 years old). The risk factors associated with HSV-2 seropositives were multiple sex partners (AOR 2.5, p = 0.04), condom non-user's (AOR 4.7, p women of Northeast India is relatively low. The generation of awareness among high risk groups may have played key role to limit the infection. The role of vaccination against HSV-2 in near future and elimination of HSV-2 viral shedding along with genital tract inflammation in high HIV/HSV-2 areas may be an option for initiating successful intervention strategies to reduce the transmission and acquisition of HIV infection in Northeast India.

  9. Prevalencia de infección por el virus del Nilo Occidental en dos zoológicos del estado de Tabasco Prevalence of West Nile Virus infection in animals from two state zoos Tabasco

    Directory of Open Access Journals (Sweden)

    M Hidalgo-Martínez

    2008-02-01

    Full Text Available OBJETIVO: Determinar la prevalencia de infección por el virus del Nilo Occidental (VNO en animales, mosquitos y personal que labora en dos zoológicos del estado de Tabasco, en México. MATERIAL Y MÉTODOS: Con la utilización de ELISA de bloqueo se detectaron anticuerpos en sueros de animales: se buscó un fragmento del genoma del VNO por RT-PCR en el suero de animales, empleados y mosquitos. RESULTADOS: En el zoológico "La Venta" se encontró una seroprevalencia de 25.67% (19/74 en aves y de 85.71% (6/7 en reptiles. En el zoológico "Yum-Ká", 31.25% (50/160 de las aves y 34.48% (16/29, de los mamíferos, tuvieron anticuerpos contra el VNO. En un grupo de mosquitos (Culex quinquefasciatus se detectó el genoma del virus. CONCLUSIONES: La detección de anticuerpos contra el VNO en animales de ambos zoológicos y del genoma viral en mosquitos demuestra la presencia del virus, lo cual representa un riesgo potencial de infección para animales y humanos.OBJECTIVE: To determine the prevalence of West Nile Virus (WNV infection in animals, mosquitoes and employees from two zoos of Tabasco state, Mexico. MATERIAL AND METHODS: WNV antibodies were detected by blocking ELISA in serum samples from animals. Viral RNA was detected by RT-PCR from mosquitoes and serum samples from employees at "Yum-Ká" zoo. RESULTS: Seroprevalence in birds was 25.65% (19/74 and 85% (6/7 in reptiles from "La Venta" zoo. Thirty-one percent of birds (50/160 and 34.48% mammals (16/29 at the "Yum-Ká" zoo, were seropositive. All human serum samples from Yum-ká zoo were negative by RT-PCR. A pool of mosquitoes (Culex quinquefasciatus was positive for WNV. CONCLUSIONS: The presence of WNV antibodies in animals from both zoos and the detection of viral genome in mosquitoes demonstrate the presence of WNV in this region and indicates a potential risk of infection in animals and humans.

  10. A note on outbreak of cowpea mild mottle virus (CPMMV) in common bean in the River Nile State, Sudan

    International Nuclear Information System (INIS)

    Hamed, A. A.; Elkhair, J.; Elfaha, A.

    2010-01-01

    An outbreak of a devastating virus disease occurred in common ben (phaseolus vulgaris) in Berber area, the River Nile State, during the 2004/2005 cropping season, with symptoms of stunting and yellowing. The disease incidence reached a level of more than 85% in all visited fields. One hundred fifty symptomatic samples, collected from different fields at Hudeiba, Berber and Shendi were blotted on nitrocellulose membranes and tested for the presence of different viruses, using the tissue blot immunoassay (TBIA) technique. The results of the serological tests revealed that 95% of the samples were positive for cowpea mild mottle virus (CPMMV). Among the common bean genotypes screened for resistance to CPMMV, only RO/2/1 and Giza 3 were resistant to the disease.(Author)

  11. Environmental and biological factors influencing Culex pipiens quinquefasciatus (Diptera: Culicidae) vector competence for West Nile Virus.

    Science.gov (United States)

    Richards, Stephanie L; Lord, Cynthia C; Pesko, Kendra N; Tabachnick, Walter J

    2010-07-01

    Interactions between environmental and biological factors affect the vector competence of Culex pipiens quinquefasciatus for West Nile virus. Three age cohorts from two Cx. p. quinquefasciatus colonies were fed blood containing a low- or high-virus dose, and each group was held at two different extrinsic incubation temperatures (EIT) for 13 days. The colonies differed in the way that they responded to the effects of the environment on vector competence. The effects of mosquito age on aspects of vector competence were dependent on the EIT and dose, and they changed depending on the colony. Complex interactions must be considered in laboratory studies of vector competence, because the extent of the genetic and environmental variation controlling vector competence in nature is largely unknown. Differences in the environmental (EIT and dose) and biological (mosquito age and colony) effects from previous studies of Cx. p. quinquefasciatus vector competence for St. Louis encephalitis virus are discussed.

  12. Noncoding Subgenomic Flavivirus RNA: Multiple Functions in West Nile Virus Pathogenesis and Modulation of Host Responses

    Directory of Open Access Journals (Sweden)

    Justin A. Roby

    2014-01-01

    Full Text Available Flaviviruses are a large group of positive strand RNA viruses transmitted by arthropods that include many human pathogens such as West Nile virus (WNV, Japanese encephalitis virus (JEV, yellow fever virus, dengue virus, and tick-borne encephalitis virus. All members in this genus tested so far are shown to produce a unique subgenomic flavivirus RNA (sfRNA derived from the 3' untranslated region (UTR. sfRNA is a product of incomplete degradation of genomic RNA by the cell 5'–3' exoribonuclease XRN1 which stalls at highly ordered secondary RNA structures at the beginning of the 3'UTR. Generation of sfRNA results in inhibition of XRN1 activity leading to an increase in stability of many cellular mRNAs. Mutant WNV deficient in sfRNA generation was highly attenuated displaying a marked decrease in cytopathicity in cells and pathogenicity in mice. sfRNA has also been shown to inhibit the antiviral activity of IFN-α/β by yet unknown mechanism and of the RNAi pathway by likely serving as a decoy substrate for Dicer. Thus, sfRNA is involved in modulating multiple cellular pathways to facilitate viral pathogenicity; however the overlying mechanism linking all these multiple functions of sfRNA remains to be elucidated.

  13. 219 ORIGINAL ARTICLE SEROPREVALENCE OF HEPATITIS C ...

    African Journals Online (AJOL)

    boaz

    ABSTRACT. Background: Hepatitis C virus (HCV) infection is a major public health concern. The aim of this study was to ascertain the seroprevalence and risk factors of HCV antibodies among pregnant women in Anyigba, Kogi State North Central Nigeria. Materials and methods:Blood samples (5mls) were collected from ...

  14. Role of Natural Killer and Gamma-Delta T cells in West Nile Virus Infection

    Directory of Open Access Journals (Sweden)

    Thomas Welte

    2013-09-01

    Full Text Available Natural Killer (NK cells and Gamma-delta T cells are both innate lymphocytes that respond rapidly and non-specifically to viral infection and other pathogens. They are also known to form a unique link between innate and adaptive immunity. Although they have similar immune features and effector functions, accumulating evidence in mice and humans suggest these two cell types have distinct roles in the control of infection by West Nile virus (WNV, a re-emerging pathogen that has caused fatal encephalitis in North America over the past decade. This review will discuss recent studies on these two cell types in protective immunity and viral pathogenesis during WNV infection.

  15. Surveillance potential of non-native Hawaiian birds for detection of West Nile Virus

    Science.gov (United States)

    Hofmeister, Erik K.; Dusek, Robert J.; Brand, Christopher J.

    2015-01-01

    West Nile virus (WNV) was first detected in North America in 1999. Alaska and Hawaii (HI) remain the only U.S. states in which transmission of WNV has not been detected. Dead bird surveillance has played an important role in the detection of the virus geographically, as well as temporally. In North America, corvids have played a major role in WNV surveillance; however, the only corvid in HI is the endangered Hawaiian crow that exists only in captivity, thus precluding the use of this species for WNV surveillance in HI. To evaluate the suitability of alternate avian species for WNV surveillance, we experimentally challenged seven abundant non-native bird species present in HI with WNV and compared mortality, viremia, oral shedding of virus, and seroconversion. For detection of WNV in oral swabs, we compared viral culture, reverse-transcriptase polymerase chain reaction, and the RAMP® test. For detection of antibodies to WNV, we compared an indirect and a competitive enzyme-linked immunoassay. We found four species (house sparrow, house finch, Japanese white-eye, and Java sparrow) that may be useful in dead bird surveillance for WNV; while common myna, zebra dove, and spotted dove survived infection and may be useful in serosurveillance.

  16. First report on the seroprevalence of the Crimean-Congo haemorrhagic fever virus, a tick-borne virus, in Malaysia's Orang Asli population.

    Science.gov (United States)

    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.

  17. Seroconversion for west Nile and St. Louis encephalitis viruses among sentinel horses in Colombia

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    Salim Mattar

    2011-12-01

    Full Text Available We prospectively sampled flavivirus-naïve horses in northern Colombia to detect West Nile virus (WNV and St. Louis encephalitis virus (SLEV seroconversion events, which would indicate the current circulation of these viruses. Overall, 331 (34.1% of the 971 horses screened were positive for past infection with flaviviruses upon initial sampling in July 2006. During the 12-month study from July 2006-June 2007, 33 WNV seroconversions and 14 SLEV seroconversions were detected, most of which occurred in the department of Bolivar. The seroconversion rates of horses in Bolivar for the period of March-June 2007 reached 12.4% for WNV and 6.7% for SLEV. These results comprise the first serologic evidence of SLEV circulation in Colombia. None of the horses sampled developed symptoms of encephalitis within three years of initial sampling. Using seroconversions in sentinel horses, we demonstrated an active circulation of WNV and SLEV in northern Colombia, particularly in the department of Bolivar. The absence of WNV-attributed equine or human disease in Colombia and elsewhere in the Caribbean Basin remains a topic of debate and speculation.

  18. HIV seroprevalence among hospital workers in Kinshasa, Zaire: lack of association with occupational exposure

    International Nuclear Information System (INIS)

    Mann, J.M.; Francis, H.; Quinn, T.C.

    1986-01-01

    A study of seroprevalence of the human immunodeficiency virus involving 2384 (96%) of Mama Yemo Hospital's (Kinshasa, Zaire) 2492 personnel found 152 (6.4%) to be seropositive. Prevalence was higher among women than among men (8.1% vs 5.2%); in women peak seroprevalence (13.9%) occurred in 20 to 29-year-olds. Workers most likely to be seropositive were those who were relatively young, those who were unmarried, those reporting a blood transfusion or hospitalization during the previous ten years, and those receiving medical injections during the previous three years. Medical, administrative, and manual workers had similar seroprevalence (6.5%, 6.4%, and 6.0%, respectively), and seropositivity was not associated with any measure of patient, blood, or needle contact. These findings are consistent with other hospital-based studies indicating low risks for occupational transmission of human immunodeficiency virus

  19. Human immuno-deficiency virus antibody seroprevalence among pregnant women at booking at a university teaching hospital in South-Eastern Nigeria.

    Science.gov (United States)

    Okeudo, C; Ezem, B U; Ojiyi, E C

    2012-01-01

    In Africa, human immuno-deficiency virus (HIV) infection continues to be progressively feminized. This has led to an increase in the number of paediatric HIV infections reported due to increased risk of mother-to-child transmission (MTCT) of HIV during pregnancy, labour and breastfeeding. The objective of the study was to determine the HIV positive sero-prevalence at booking among pregnant women at the Imo State University Teaching Hospital, Orlu. A retrospective analysis of the case records of women who booked and were screened for Human Immune-deficiency Virus at the Imo State University Teaching Hospital (IMSUTH), Orlu from 1st March 2008 to 28th February 2010 was done. Data on age, parity, educational status, gestational age at booking, and retroviral status were collected and analysed using spss version 13. Nine hundred and twenty one pregnant women were screened for the presence of HIV 1 & 2 antibodies in their serum. One hundred and six of them were positive, giving a sero-prevalence rate at booking of 11.5%. The highest sero prevalence rate of 45.2% occurred in the age group of 26-30 years. Petty traders contributed 97 (91.5%) of the HIV positive women, while multiparous (para 2-4) women contributed 50% of the positive pregnant women. Only 32 (30.2%) of the HIV positive women booked within the first trimester for antenatal care. Majority 53 (59.4%) of the HIV positive women had secondary education, while those that had no formal education contributed only 6 (5.7%) of the HIV positive women. There was a high HIV seroprevalence at booking among pregnant women at IMSUTH, Orlu. A lot more needs to be done in order to reduce vertical transmission of HIV in our environment.

  20. Spatio-temporal epidemiology of human West Nile virus disease in South Dakota.

    Science.gov (United States)

    Wimberly, Michael C; Giacomo, Paolla; Kightlinger, Lon; Hildreth, Michael B

    2013-10-29

    Despite a cold temperate climate and low human population density, the Northern Great Plains has become a persistent hot spot for human West Nile virus (WNV) disease in North America. Understanding the spatial and temporal patterns of WNV can provide insights into the epidemiological and ecological factors that influence disease emergence and persistence. We analyzed the 1,962 cases of human WNV disease that occurred in South Dakota from 2002-2012 to identify the geographic distribution, seasonal cycles, and interannual variability of disease risk. The geographic and seasonal patterns of WNV have changed since the invasion and initial epidemic in 2002-2003, with cases shifting toward the eastern portion of South Dakota and occurring earlier in the transmission season in more recent years. WNV cases were temporally autocorrelated at lags of up to six weeks and early season cumulative case numbers were correlated with seasonal totals, indicating the possibility of using these data for short-term early detection of outbreaks. Epidemiological data are likely to be most effective for early warning of WNV virus outbreaks if they are integrated with entomological surveillance and environmental monitoring to leverage the strengths and minimize the weaknesses of each information source.

  1. Seroprevalence of Human Papillomavirus Types 6, 11, 16 and 18 in Chinese Women

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    Ji Jia

    2012-06-01

    Full Text Available Abstract Background Human papillomavirus (HPV seroprevalence data have not previously been reported for different geographical regions of China. This study investigated the cross-sectional seroprevalence of antibodies to HPV 6, 11, 16, and 18 virus-like particles in Chinese women. Methods Population-based samples of women were enrolled from 2006 to 2007 in 3 rural and 2 urban areas of China. Each consenting woman completed a questionnaire and provided a blood sample. Serum antibodies were detected using a competitive Luminex immunoassay that measures antibodies to type-specific, neutralizing epitopes on the virus-like particles. Results A total of 4,731 women (median age 35, age range 14-54 were included, of which 4,211 were sexually active women (median age 37 and 520 virgins (median age 18. Low risk HPV 6 was the most common serotype detected (7.3%, followed by HPV 16 (5.6%, HPV 11 (2.9%, and HPV 18 (1.9%. Overall HPV seroprevalence to any type was significantly higher among sexually active women (15.8% than virgins (2.5% (P = 0.005. Overall seroprevalence among sexually active women gradually increased with age. Women from rural regions had significantly lower overall seroprevalence (Odds Ratio (OR = 0.7; 95% CI: 0.6-0.9, versus metropolitan regions, P  = 4 partners versus 1 partner, P  Conclusions HPV seroprevalence differed significantly by age, geography, and sexual behavior within China, which all should be considered when implementing an optimal prophylactic HPV vaccination program in China.

  2. Protection against West Nile virus infection in mice after inoculation with type I interferon-inducing RNA transcripts.

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    Miguel Rodríguez-Pulido

    Full Text Available West Nile virus (WNV is a neurovirulent single stranded RNA mosquito-borne flavivirus, whose main natural hosts are birds, but it also infects humans and horses. Nowadays, no human vaccine is commercially available and clinical treatment is only supportive. Recently, it has been shown that RNA transcripts, mimicking structural domains in the non-coding regions (NCRs of the foot-and mouth disease virus (FMDV induce a potent IFN response and antiviral activity in transfected cultured cells, and also reduced mice susceptibility to FMDV. By using different transcripts combinations, administration schedules, and infecting routes and doses, we have demonstrated that these FMDV RNA transcripts protect suckling and adult mice against lethal challenge with WNV. The protective activity induced by the transcripts was systemic and dependent on the infection route and dose. These results confirm the antiviral potential of these synthetic RNAs for fighting viruses of different families relevant for human and animal health.

  3. Potential for Co-Infection of a Mosquito-Specific Flavivirus, Nhumirim Virus, to Block West Nile Virus Transmission in Mosquitoes

    Directory of Open Access Journals (Sweden)

    Silvina Goenaga

    2015-11-01

    Full Text Available Nhumirim virus (NHUV is an insect-specific virus that phylogenetically affiliates with dual-host mosquito-borne flaviviruses. Previous in vitro co-infection experiments demonstrated prior or concurrent infection of Aedes albopictus C6/36 mosquito cells with NHUV resulted in a 10,000-fold reduction in viral production of West Nile virus (WNV. This interference between WNV and NHUV was observed herein in an additional Ae. albopictus mosquito cell line, C7-10. A WNV 2K peptide (V9M mutant capable of superinfection with a pre-established WNV infection demonstrated a comparable level of interference from NHUV as the parental WNV strain in C6/36 and C7-10 cells. Culex quinquefasciatus and Culex pipiens mosquitoes intrathoracically inoculated with NHUVandWNV, or solely withWNVas a control, were allowed to extrinsically incubate the viruses up to nine and 14 days, respectively, and transmissibility and replication of WNV was determined. The proportion of Cx. quinquefasciatus mosquitoes capable of transmitting WNV was significantly lower for the WNV/NHUV group than the WNV control at seven and nine days post inoculation (dpi, while no differences were observed in the Cx. pipiens inoculation group. By dpi nine, a 40% reduction in transmissibility in mosquitoes from the dual inoculation group was observed compared to the WNV-only control. These data indicate the potential that infection of some Culex spp. vectors with NHUV could serve as a barrier for efficient transmissibility of flaviviruses associated with human disease.

  4. Induction of antigen-specific immune responses in mice by recombinant baculovirus expressing premembrane and envelope proteins of West Nile virus

    Directory of Open Access Journals (Sweden)

    Zhu Bibo

    2012-07-01

    Full Text Available Abstract Background West Nile Virus (WNV is an emerging arthropod-born flavivirus with increasing distribution worldwide that is responsible for a large proportion of viral encephalitis in humans and horses. Given that there are no effective antiviral drugs available for treatment of the disease, efforts have been directed to develop vaccines to prevent WNV infection. Recently baculovirus has emerged as a novel and attractive gene delivery vehicle for mammalian cells. Results In the present study, recombinant baculoviruses expressing WNV premembrane (prM and envelope (E proteins under the cytomegalovirus (CMV promoter with or without vesicular stomatitis virus glycoprotein (VSV/G were constructed. The recombinant baculoviruses designated Bac-G-prM/E and Bac-prM/E, efficiently express E protein in mammalian cells. Intramuscular injection of the two recombinant baculoviruses (at doses of 108 or 109 PFU/mouse induced the production of WNV-specific antibodies, neutralizing antibodies as well as gamma interferon (IFN-γ in a dose-dependent pattern. Interestingly, the recombinant baculovirus Bac-G-prM/E was found to be a more efficient immunogen than Bac-prM/E to elicit a robust immune response upon intramuscular injection. In addition, inoculation of baculovirus resulted in the secretion of inflammatory cytokines, such as TNF-α, IL-2 and IL-6. Conclusions These recombinant baculoviruses are capable of eliciting robust humoral and cellular immune responses in mice, and may be considered as novel vaccine candidates for West Nile Virus.

  5. Seroprevalence study of Equine rhinitis B virus (ERBV) in Australian weanling horses using serotype-specific ERBV enzyme-linked immunosorbent assays.

    Science.gov (United States)

    Horsington, Jacquelyn; Hartley, Carol A; Gilkerson, James R

    2013-09-01

    Respiratory infections are a major burden in the performance horse industry. Equine rhinitis B virus (ERBV) has been isolated from horses displaying clinical respiratory disease, and ERBV-neutralizing antibodies have been detected in 50-80% of horses in reported surveys. Current ERBV isolation and detection methods may underestimate the number of ERBV-positive animals and do not identify multiple serotype infections. The aim of the current study was to develop a serotyping ERBV antibody-detection enzyme-linked immunosorbent assay (ELISA) and examine the seroprevalence of ERBV in a group of Australian weanling horses. ELISAs with high sensitivity and specificity were developed. The seroprevalence of ERBV in the weanling horses was high (74-86%); ERBV-3 antibodies were most prevalent (58-62%) and ERBV-2 antibodies were least prevalent (10-16%). Many horses were seropositive to 2 or more serotypes. All 3 serotypes of ERBV were detected, and concurrent positivity to multiple serotypes was common.

  6. West Nile virus lineage 2 infection in a blood donor from Vienna, Austria, August 2014.

    Science.gov (United States)

    Jungbauer, C; Hourfar, M K; Stiasny, K; Aberle, S W; Cadar, D; Schmidt-Chanasit, J; Mayr, W R

    2015-03-01

    Eastern Austria is neighbouring regions with ongoing West Nile virus (WNV) transmissions. Three human WNV infections had been diagnosed during the past decade in Austria. The Austrian Red Cross Blood Service (ARC-BS) started a first voluntary screening for WNV in blood donors from Eastern Austria by Nucleic Acid Testing (NAT) in June 2014. This is also the most extensive WNV surveillance programme in humans in Austria so far. In August 2014, one autochthonous WNV infection was detected in a blood donor from Vienna. By now, one in 67,800 whole blood donations was found to be positive for WNV RNA. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Susceptibility of Carrion Crows to Experimental Infection with Lineage 1 and 2 West Nile Viruses.

    Science.gov (United States)

    Lim, Stephanie M; Brault, Aaron C; van Amerongen, Geert; Bosco-Lauth, Angela M; Romo, Hannah; Sewbalaksing, Varsha D; Bowen, Richard A; Osterhaus, Albert D M E; Koraka, Penelope; Martina, Byron E E

    2015-08-01

    West Nile virus (WNV) outbreaks in North America have been characterized by substantial die-offs of American crows (Corvus brachyrhynchos). In contrast, a low incidence of bird deaths has been observed during WNV epidemic activity in Europe. To examine the susceptibility of the western European counterpart of American crows, we inoculated carrion crows (Corvus corone) with WNV strains isolated in Greece (Gr-10), Italy (FIN and Ita09), and Hungary (578/10) and with the highly virulent North American genotype strain (NY99). We also inoculated American crows with a selection of these strains to examine the strains' virulence in a highly susceptible bird species. Infection with all strains, except WNV FIN, resulted in high rates of death and high-level viremia in both bird species and virus dissemination to several organs. These results suggest that carrion crows are highly susceptible to WNV and may potentially be useful as part of dead bird surveillance for early warning of WNV activity in Europe.

  8. Naturally induced humoral immunity to West Nile virus infection in raptors.

    Science.gov (United States)

    Nemeth, Nicole M; Kratz, Gail E; Bates, Rebecca; Scherpelz, Judy A; Bowen, Richard A; Komar, Nicholas

    2008-09-01

    West Nile virus (WNV) infection can be fatal to many bird species, including numerous raptors, though population- and ecosystem-level impacts following introduction of the virus to North America have been difficult to document. Raptors occupy a diverse array of habitats worldwide and are important to ecosystems for their role as opportunistic predators. We documented initial (primary) WNV infection and then regularly measured WNV-specific neutralizing antibody titers in 16 resident raptors of seven species, plus one turkey vulture. Most individuals were initially infected and seroconverted between July and September of 2003, though three birds remained seronegative until summer 2006. Many of these birds became clinically ill upon primary infection, with clinical signs ranging from loss of appetite to moderate neurological disease. Naturally induced WNV neutralizing antibody titers remained essentially unchanged in some birds, while eight individuals experienced secondary rises in titer presumably due to additional exposures at 1, 2, or 3 years following primary infection. No birds experienced clinical signs surrounding or following the time of secondary exposure, and therefore antibodies were considered protective. Results of this study have implications for transmission dynamics of WNV and health of raptor populations, as well as the interpretation of serologic data from free-ranging and captive birds. Antibodies in raptors surviving WNV may persist for multiple years and protect against potential adverse effects of subsequent exposures.

  9. Seroprevalence of viral and bacterial diseases among the bovines in Himachal Pradesh, India

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    Shailja Katoch

    2017-12-01

    Full Text Available Aim: The study was designed to measure the seroprevalence of viral and bacterial diseases: Infectious bovine rhinotracheitis, bovine viral diarrhea, bovine leukemia, bovine parainfluenza, bovine respiratory syncytial disease, brucellosis, and paratuberculosis among bovine of Himachal Pradesh during the year 2013-2015. Materials and Methods: The serum samples were collected from seven districts of state, namely, Bilaspur, Kangra, Kinnaur, Lahul and Spiti, Mandi, Sirmour, and Solan. The samples were screened using indirect ELISA kits to measure the seroprevalence of viral and bacterial diseases. Results: The overall seroprevalence of infectious bovine rhinotracheitis was 24.24%, bovine viral diarrhea 1.52%, bovine leukemia 9.09%, bovine parainfluenza 57.58%, bovine respiratory syncytial disease 50%, brucellosis 19.69%, and paratuberculosis 9.09% in Himachal Pradesh. The seroprevalence of bovine rhinotracheitis, bovine leukemia, bovine parainfluenza, bovine respiratory syncytial disease, and paratuberculosis in the state varied significantly (p0.01. Multiple seropositivity has been observed in this study. Bovine parainfluenza virus 3 was observed commonly in mixed infection with almost all viruses and bacteria under study. Conclusion: The viral and bacterial diseases are prevalent in the seven districts of Himachal Pradesh investigated in the study. Therefore, appropriate management practices and routine vaccination programs should be adopted to reduce the prevalence of these diseases.

  10. Foot-and-Mouth Disease Seroprevalence in Cattle in Eritrea

    NARCIS (Netherlands)

    Tekleghiorghis, T.; Weerdmeester, K.; Hemert-Kluitenberg, van Froukje; Moormann, R.J.M.; Dekker, Aldo

    2017-01-01

    Information about seroprevalence of foot-and-mouth disease (FMD) and virus serotypes in Eritrea is unavailable, but is very important as it may guide the choice of intervention measures including vaccination to be implemented. We carried out a cross-sectional study from February to June 2011 in

  11. Severe neuroinvasive West Nile virus infection in a child with undiagnosed Addison's disease

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    Kevin Messacar

    2014-01-01

    Full Text Available This report describes a case of West Nile virus (WNV meningoencephalitis in a child who presented with fever, headache, seizures, and altered mental status, as well as hyponatremia and bronzing of the skin. Findings that led to the diagnosis of WNV included plasma-cell pleocytosis of the cerebrospinal fluid (CSF and linear chorioretinitis on ophthalmologic exam. The diagnosis was confirmed by a positive serum and CSF WNV IgM. The acute WNV infection triggered an adrenal crisis which uncovered a new diagnosis of underlying Addison's disease. This is the first case report of severe neuroinvasive WNV disease in a pediatric patient with primary adrenal insufficiency. Neuroinvasive WNV disease is uncommon in children, but may have a more severe presentation in those with certain underlying medical conditions.

  12. A CRISPR-Based Screen Identifies Genes Essential for West-Nile-Virus-Induced Cell Death.

    Science.gov (United States)

    Ma, Hongming; Dang, Ying; Wu, Yonggan; Jia, Gengxiang; Anaya, Edgar; Zhang, Junli; Abraham, Sojan; Choi, Jang-Gi; Shi, Guojun; Qi, Ling; Manjunath, N; Wu, Haoquan

    2015-07-28

    West Nile virus (WNV) causes an acute neurological infection attended by massive neuronal cell death. However, the mechanism(s) behind the virus-induced cell death is poorly understood. Using a library containing 77,406 sgRNAs targeting 20,121 genes, we performed a genome-wide screen followed by a second screen with a sub-library. Among the genes identified, seven genes, EMC2, EMC3, SEL1L, DERL2, UBE2G2, UBE2J1, and HRD1, stood out as having the strongest phenotype, whose knockout conferred strong protection against WNV-induced cell death with two different WNV strains and in three cell lines. Interestingly, knockout of these genes did not block WNV replication. Thus, these appear to be essential genes that link WNV replication to downstream cell death pathway(s). In addition, the fact that all of these genes belong to the ER-associated protein degradation (ERAD) pathway suggests that this might be the primary driver of WNV-induced cell death. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  13. Identification of environmental covariates of West Nile virus vector mosquito population abundance.

    Science.gov (United States)

    Trawinski, Patricia R; Mackay, D Scott

    2010-06-01

    The rapid spread of West Nile virus (WNv) in North America is a major public health concern. Culex pipiens-restuans is the principle mosquito vector of WNv in the northeastern United States while Aedes vexans is an important bridge vector of the virus in this region. Vector mosquito abundance is directly dependent on physical environmental factors that provide mosquito habitats. The objective of this research is to determine landscape elements that explain the population abundance and distribution of WNv vector mosquitoes using stepwise linear regression. We developed a novel approach for examining a large set of landscape variables based on a land use and land cover classification by selecting variables in stages to minimize multicollinearity. We also investigated the distance at which landscape elements influence abundance of vector populations using buffer distances of 200, 400, and 1000 m. Results show landscape effects have a significant impact on Cx. pipiens-estuans population distribution while the effects of landscape features are less important for prediction of Ae. vexans population distributions. Cx. pipiens-restuans population abundance is positively correlated with human population density, housing unit density, and urban land use and land cover classes and negatively correlated with age of dwellings and amount of forested land.

  14. 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.

  15. West Nile Virus in Mosquitoes of Iranian Wetlands.

    Science.gov (United States)

    Bagheri, Masoomeh; Terenius, Olle; Oshaghi, Mohammad Ali; Motazakker, Morteza; Asgari, Sassan; Dabiri, Farrokh; Vatandoost, Hassan; Mohammadi Bavani, Mulood; Chavshin, Ali Reza

    2015-12-01

    The West Nile virus (WNV) transmission cycle includes a wide range of migratory wetland birds as reservoirs, mosquitoes as biological vectors, and equines and humans as dead-end hosts. Despite the presence of potential vector species, there is no information about the existence of WNV in mosquito vectors in Iran. The Iranian West Azerbaijan Province is located in the northwestern part of Iran and has borders with Turkey, Iraq, Armenia, and the Republic of Azerbaijan. The current study was conducted to identify the wetland mosquitoes of the West Azerbaijan Province and their infection with WNV. In this study, 2143 specimens were collected, comprising 1541 adults and 602 larvae. Six species belonging to four genera were collected and identified: Anopheles maculipennis sensu lato (s.l.), Culex (Cx.) hortensis, Cx. pipiens s.l., Cx. theileri, Culiseta longiareolata, and Aedes (Ae.) (Ochlerotatus) caspius. In total, 45 pools of mosquitoes were examined. Two of the adult pools collected from the same location showed the presence of WNV in Ae. (Och.) caspius, from Sangar, Makoo County, as confirmed by PCR and sequencing. Due to the discovery of WNV in the mosquito population of the region, and the presence of wetlands and significant populations of migratory birds, the health sector should carefully monitor the factors involved in the cycle of this disease.

  16. Evolutionary relationship between Old World West Nile virus strains Evidence for viral gene flow between africa, the middle east, and europe

    International Nuclear Information System (INIS)

    Charrel, R.N.; Brault, A.C.; Gallian, P.; Lemasson, J.-J.; Murgue, B.; Murri, S.; Pastorino, B.; Zeller, H.; Chesse, R. de; Micco, P. de; Lamballerie, X. de

    2003-01-01

    Little is known about the genetic relationships between European and other Old-World strains of West Nile virus (WNV) and persistence of WNV North of Mediterranean. We characterized the complete genomes of three WNV strains from France (horse-2000), Tunisia (human-1997) and Kenya (mosquito-1998), and the envelope, NS3 and NS5 genes of the Koutango virus. Phylogenetic analyses including all available full-length sequences showed that: (1) Koutango virus is a distant variant of WNV; (2) the three characterized strains belong to lineage 1, clade 1a; (3) the Tunisian strain roots the lineage of viruses introduced in North America. We established that currently available partial envelope sequences do not generate reliable phylogenies. Accordingly, establishing a large WNV sequence database is pivotal for the understanding of spatial and temporal epidemiology of this virus. For rapid completion of that purpose, colinearized E-NS3-NS5 gene sequences were shown to constitute a valuable surrogate for complete sequences

  17. Seroprevalence immunodeficiency virus and feline leukemia in cats in Monteria, Córdoba SEROPREVALENCIA DEL VIRUS DE LEUCEMIA E INMUNODEFICIENCIA FELINA EN GATOS DE MONTERÍA, CÓRDOBA

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    Ríos Rincón Rodrigo Alexander

    2009-04-01

    Full Text Available The gradual increment of the feline population in Colombia and some countries is associated with presence of diseases that care produce animal health risk. The virus of immunodeficiency and the feline leukemia are the main retroviales diseases with high morbility and mortality in felines and they require of a right diagnostic that extend the felines’ life. A descriptive transversal cut study was done, 60 urban domestic cats of Montería were included, animals were from clinics, veterinarian consults and familiar houses. The simultaneous diagnostic of leukemia and feline immunodeficiency was carried out by using inmunoensayo SNAP combo FeLV Ag/FIV Ab (laboratories Idexx Toronto, Canadá in samples of serum and plasma. The animals were submitted to a physical and laboratory examination the population studied were 30 females and 30 males most of them minor of 2 years. Feline leukemia showed a seroprevalence of 23,3% (14/60, for feline immunodeficiency a seroprevalence of 1,6% (1/60, and the prevalence of double infection for feline leukemia and immunodeficiency was of 5% (3/60. The immunodeficiency’s virus and feline leukemia diagnostic was carry out for first time in the population of domestics cats in the city of Montería and it established a seroprevalence of 23,3% and 1,6% respectively.El incremento gradual de la población felina en Colombia y algunos países está acompañado de la aparición de enfermedades que ponen en riesgo la salud animal. El virus de inmunodeficiencia y la leucemia felina son las principales enfermedades retrovirales de mayor morbilidad y mortalidad en los felinos, que requieren de un diagnóstico oportuno que permita prolongar la vida de estos animales. Se realizó un estudio descriptivo de corte transversal que incluyó 60 gatos domésticos del área urbana de la ciudad de Montería procedentes de clínicas, consultorios veterinarios y viviendas familiares. El diagnóstico simultáneo de leucemia e

  18. Estimating the economic impact of a possible equine and human epidemic of West Nile virus infection in Belgium.

    Science.gov (United States)

    Humblet, Marie-France; Vandeputte, Sébastien; Fecher-Bourgeois, Fabienne; Léonard, Philippe; Gosset, Christiane; Balenghien, Thomas; Durand, Benoît; Saegerman, Claude

    2016-08-04

    This study aimed at estimating, in a prospective scenario, the potential economic impact of a possible epidemic of WNV infection in Belgium, based on 2012 values for the equine and human health sectors, in order to increase preparedness and help decision-makers. Modelling of risk areas, based on the habitat suitable for Culex pipiens, the main vector of the virus, allowed us to determine equine and human populations at risk. Characteristics of the different clinical forms of the disease based on past epidemics in Europe allowed morbidity among horses and humans to be estimated. The main costs for the equine sector were vaccination and replacement value of dead or euthanised horses. The choice of the vaccination strategy would have important consequences in terms of cost. Vaccination of the country's whole population of horses, based on a worst-case scenario, would cost more than EUR 30 million; for areas at risk, the cost would be around EUR 16-17 million. Regarding the impact on human health, short-term costs and socio-economic losses were estimated for patients who developed the neuroinvasive form of the disease, as no vaccine is available yet for humans. Hospital charges of around EUR 3,600 for a case of West Nile neuroinvasive disease and EUR 4,500 for a case of acute flaccid paralysis would be the major financial consequence of an epidemic of West Nile virus infection in humans in Belgium. This article is copyright of The Authors, 2016.

  19. Chikungunya virus outbreak in Kerala, India, 2007: a seroprevalence study

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    Narendran Pradeep Kumar

    2011-12-01

    Full Text Available India was affected by a major outbreak of chikungunya fever caused by Chikungunya virus (CHIKV during 2006-2007. Kerala was the worst affected state during 2007 with a contribution of 55.8% suspected cases in the country. However, except for clinically reported case records, no systematic information is available on infection status of CHIKV in the region. Hence, we carried out a post-epidemic survey to estimate seroprevalence status [immunoglobulin G (IgG] in the community using commercially available indirect immunofluorescence test. This methodology had been reported to be highly specific and sensitive for CHIKV infection. The study area selected was the worst affected mid-highlands region of Kerala which harbour vast area of rubber plantations. The study evidenced 68% of the population to be seropositive for CHIKV IgG. Males were found more affected than females (χ2 = 9.86; p = 0.002. Among males, prevalence was significantly higher in the age classes 21-30 (χ2 = 5.46; p = 0.019 and 31-40 (χ2 = 5.84; p = 0.016 years. This may be due to high occupational risk of the male population engaged in plantation activities exposed to infective bites of Aedes albopictus. The current study provides an insight into the magnitude of CHIKV outbreak in Kerala.

  20. A large-scale seroprevalence of Epstein-Barr virus in Taiwan.

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    Chao-Yu Chen

    Full Text Available Epstein-Barr virus (EBV causes a variety of clinical manifestations from asymptomatic infection to acute infectious mononucleosis in human. Moreover, the EBV infection is associated with malignancies. The large-scale EBV seroepidemiology across all age groups has been lacking in Taiwan.A total of 1411 serum samples were tested to examine the seroprevalence of EBV in 2007. The samples were collected during an island-wide seroepidemiological survey of vaccine preventable diseases in Taiwan. The enzyme-linked immunosorbent assay was performed to detect anti-EBV viral capsid IgG in sera. Demographic and personal health data were obtained by questionnaires.The overall weighted seropositive rate of EBV was 88.5% (95% CI, 86.7%-90.1%. The seropositive rate of EBV reached 52.8% (95% CI, 44.0%-61.6% in children aged 2 years, rapidly rose to 88.7% (95% CI, 79.0%-95.1% in those aged 5-7 years and 93.0% (95%CI, 83.0%-98.1% for those aged 14-16 years. Age and higher educational level were associated with the increased EBV seropositive rate.In Taiwan, people had the EBV infection early in life. Children under 7 years should be the primary target popution of public health measures in the future.

  1. Seroprevalence of hepatitis E virus in the UK farming population.

    Science.gov (United States)

    Meader, E; Thomas, D; Salmon, R; Sillis, M

    2010-12-01

    Hepatitis E is a zoonosis that can be acquired by the consumption of contaminated food or water, or via person-to-person spread. However, little is known about the transmission of hepatitis E virus (HEV) in the UK. We investigated the epidemiology of indigenous hepatitis E infection using the PHLS Farm Cohort, a sentinel group with a history of close contact with a range of domestic animals. Ten of the 413 subjects tested were positive for hepatitis E IgG antibodies (2.4%). Seroprevalence peaked in those aged 51 to 60 years (relative risk 3.3, 95% CI: 1.0-10.5). Male participants (relative risk 3.6, 95% CI: 0.6-21.2) and those from farms in the Hereford area of the United Kingdom (relative risk 2.7, 95% CI: 0.8-8.4), an area of mixed livestock farming, were more likely to have serological evidence of previous HEVs exposure, although these findings were not statistically significant. Exposure to pigs, or water from a private supply, was not identified as a significant risk factor. The results of this study suggest that UK farming populations are exposed to HEV, but the predominant route of transmission remains elusive. © 2009 The Authors. Journal compilation © 2009 Blackwell Verlag GmbH.

  2. Seroprevalence of hepatitis B Sur- face antigen among apparently ...

    African Journals Online (AJOL)

    2012-01-08

    Jan 8, 2012 ... and provision of universal HBV vaccination should be given urgent priority. Keywords: Children, HBsAg,. Primary school, Seroprevalence. Introduction. Hepatitis B virus infection is a disease of global distri- bution and constitutes a major public health prob- lem.1More than one third of the world's population ...

  3. Seroprevalence of hepatitis B and C viral co-infections among children infected with human immunodeficiency virus attending the paediatric HIV care and treatment center at Muhimbili National Hospital in Dar-es-Salaam, Tanzania

    Directory of Open Access Journals (Sweden)

    Munubhi Emmanuel K

    2007-11-01

    Full Text Available Abstract Background With increased availability of antibiotics and antifungal agents hepatitis B virus (HBV and hepatitis C virus (HCV infections are becoming a cause for significant concern in HIV infected children. We determined the seroprevalence and risk factors for HBV and HCV among HIV infected children aged 18 months to 17 years, attending the Paediatric HIV Care and Treatment Center (CTC at Muhimbili National Hospital (MNH in Dar-es-Salaam, Tanzania. Methods Investigations included; interviews, physical examination and serology for HBsAg, IgG antibodies to HCV and alanine aminotransferase (ALT levels. HIV serostatus and CD4 counts were obtained from patient records. Results 167 HIV infected children, 88(52.7% males and 79(47.3% females were enrolled. The overall prevalence of hepatitis co-infection was 15%, with the seroprevalence of HBV and HCV being 1.2% and 13.8%, respectively. Hepatitis virus co-infection was not associated with any of the investigated risk factors and there was no association between HBV and HCV. Elevated ALT was associated with hepatitis viral co-infection but not with ART usage or immune status. Conclusion The high seroprevalence (15% of hepatitis co-infection in HIV infected children attending the Paediatrics HIV CTC at the MNH calls for routine screening of hepatitis viral co-infection and modification in the management of HIV infected children.

  4. Mosquito politics: local vector control policies and the spread of West Nile Virus in the Chicago region.

    Science.gov (United States)

    Tedesco, Carmen; Ruiz, Marilyn; McLafferty, Sara

    2010-11-01

    Differences in mosquito control practices at the local level involve the interplay of place, scale and politics. During the Chicago West Nile Virus (WNV) outbreak of 2002, mosquito abatement districts represent distinct suburban clusters of human WNV cases, independent of characteristics of the local population, housing and physical environment. We examine how the contrasting actions of four districts reveal a distinct local politics of mosquito control that may have contributed to local-scale geographic differences in WNV incidence. This politics is rooted in political, economic and philosophical differences within and between administrative boundaries. Copyright © 2010 Elsevier Ltd. All rights reserved.

  5. Seroprevalence of Brucellosis in Human Immunodeficiency Virus Infected Patients in Hamadan, Iran

    Science.gov (United States)

    Keramat, Fariba; Majzobi, Mohammad Mehdi; Poorolajal, Jalal; Ghane, Zohreh Zarei; Adabi, Maryam

    2017-01-01

    Objectives Brucellosis is a systemic disease with a wide spectrum of clinical manifestations. This study aimed to determine the seroprevalence of brucellosis in human immunodeficiency virus (HIV) infected patients in Hamadan Province in the west of Iran. Methods A total of 157 HIV-infected patients were screened through standard serological tests, including Wright’s test, Coombs’ Wright test, and 2-mercaptoethanol Brucella agglutination test (2ME test), blood cultures in Castaneda media, and CD4 counting. Data were analyzed using Stata version 11. Results Wright and Coombs’ Wright tests were carried out, and only 5 (3.2%) patients had positive serological results. However, all patients had negative 2ME results, and blood cultures were negative for Brucella spp. Moreover, patients with positive serology and a mean CD4 count of 355.8 ± 203.11 cells/μL had no clinical manifestations of brucellosis, and, and the other patients had a mean CD4 count of 335.55 ± 261.71 cells/μL. Conclusion Results of this study showed that HIV infection is not a predisposing factor of acquiring brucellosis. PMID:28904852

  6. Hepatitis E virus seroprevalence rate among Eastern Mediterranean and middle eastern countries; A systematic review and pooled analysis.

    Science.gov (United States)

    Karbalaie Niya, Mohammad Hadi; Rezaee-Zavareh, Mohammad Saeid; Ranaei, Alireza; Alavian, Seyed Moayed

    2017-09-01

    Hepatitis E virus (HEV) as a hepatotropic virus is one of the major global health concerns. Autochthonous HEV transmitted by oral fecal-route in poor sanitation conditions as well as vertical and rarely blood transfusion. HEV occurrence is more common in developing countries and recently increased in developed countries too. Middle East (ME) and Eastern Mediterranean region (EMR) of WHO have been an endemic region for HEV infection. In this regard, we aimed to design a systematic review and pooled analysis to determine seroprevalence of anti-HEV antibody in ME and EMR countries. By using PRISMA guideline, data were collected from papers identified through PubMed, Web of Science, Science Direct, Scopus and also from some national and regional databases from January 1990 to June 2016. Serum anti-HEV antibody (IgG) used for HEV prevalence estimation. HEV prevalence in the ME, WHO EMR countries, and in total, calculated by each country population size based on 2015 UN report. overall, 62 papers with a total sample size of 31,673 were fulfilled our eligibility criteria and included in our project. Considering anti-HEV antibody (IgG), prevalence of HEV infection in the countries of ME, WHO EMR and in total were 12.17% (95% CI: 11.79-12.57), 11.81% (95% CI: 11.43-12.21), and 11.87% (95% CI: 11.52-12.23) respectively. HEV seroprevalence in WHO EMR and ME countries has high rate and more considerations are needed for the prevention and control of this infection especially in high-risk groups such as pregnant women. Copyright © 2017. Published by Elsevier Ltd.

  7. Simultaneous detection and differentiation of dengue virus serotypes 1-4, Japanese encephalitis virus, and West Nile virus by a combined reverse-transcription loop-mediated isothermal amplification assay

    Directory of Open Access Journals (Sweden)

    Yin Jianhua

    2011-07-01

    Full Text Available Abstract Background Rapid identification and differentiation of mosquito-transmitted flaviviruses in acute-phase sera of patients and field-caught vector mosquitoes are important for the prediction and prevention of large-scale epidemics. Results We developed a flexible reverse-transcription loop-mediated isothermal amplification (RT-LAMP unit for the detection and differentiation of dengue virus serotypes 1-4 (DENV1-4, Japanese encephalitis virus (JEV, and West Nile virus (WNV. The unit efficiently amplified the viral genomes specifically at wide ranges of viral template concentrations, and exhibited similar amplification curves as monitored by a real-time PCR engine. The detection limits of the RT-LAMP unit were 100-fold higher than that of RT-PCR in 5 of the six flaviviruses. The results on specificity indicated that the six viruses in the assay had no cross-reactions with each other. By examining 66 viral strains of DENV1-4 and JEV, the unit identified the viruses with 100% accuracy and did not cross-react with influenza viruses and hantaviruses. By screening a panel of specimens containing sera of 168 patients and 279 pools of field-caught blood sucked mosquitoes, results showed that this unit is high feasible in clinical settings and epidemiologic field, and it obtained results 100% correlated with real-time RT-PCR. Conclusions The RT-LAMP unit developed in this study is able to quickly detect and accurately differentiate the six kinds of flaviviruses, which makes it extremely feasible for screening these viruses in acute-phase sera of the patients and in vector mosquitoes without the need of high-precision instruments.

  8. West Nile virus lineage 2 isolated from Culex modestus mosquitoes in the Czech Republic, 2013: expansion of the European WNV endemic area to the North?

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Bakonyi, T.; Šebesta, Oldřich; Mendel, Jan; Peško, Juraj; Betášová, Lenka; Blažejová, Hana; Venclíková, Kristýna; Straková, Petra; Nowotny, N.; Hubálek, Zdeněk

    2014-01-01

    Roč. 19, č. 31 (2014), pii=20867 ISSN 1560-7917 EU Projects: European Commission(XE) 261504 - EDENEXT Institutional support: RVO:68081766 Keywords : West Nile virus * mosquitoes * Czech Republic Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 5.722, year: 2014 http://www.eurosurveillance.org/ViewArticle.aspx?ArticleId=20867

  9. Stress hormones predict a host superspreader phenotype in the West Nile virus system

    Science.gov (United States)

    Gervasi, Stephanie; Burgan, Sarah; Hofmeister, Erik K.; Unnasch, Thomas R.; Martin, Lynn B.

    2017-01-01

    Glucocorticoid stress hormones, such as corticosterone (CORT), have profound effects on the behaviour and physiology of organisms, and thus have the potential to alter host competence and the contributions of individuals to population- and community-level pathogen dynamics. For example, CORT could alter the rate of contacts among hosts, pathogens and vectors through its widespread effects on host metabolism and activity levels. CORT could also affect the intensity and duration of pathogen shedding and risk of host mortality during infection. We experimentally manipulated songbird CORT, asking how CORT affected behavioural and physiological responses to a standardized West Nile virus (WNV) challenge. Although all birds became infected after exposure to the virus, only birds with elevated CORT had viral loads at or above the infectious threshold. Moreover, though the rate of mortality was faster in birds with elevated CORT compared with controls, most hosts with elevated CORT survived past the day of peak infectiousness. CORT concentrations just prior to inoculation with WNV and anti-inflammatory cytokine concentrations following viral exposure were predictive of individual duration of infectiousness and the ability to maintain physical performance during infection (i.e. tolerance), revealing putative biomarkers of competence. Collectively, our results suggest that glucocorticoid stress hormones could directly and indirectly mediate the spread of pathogens.

  10. Local impact of temperature and precipitation on West Nile virus infection in Culex species mosquitoes in northeast Illinois, USA

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    Haramis Linn

    2010-03-01

    Full Text Available Abstract Background Models of the effects of environmental factors on West Nile virus disease risk have yielded conflicting outcomes. The role of precipitation has been especially difficult to discern from existing studies, due in part to habitat and behavior characteristics of specific vector species and because of differences in the temporal and spatial scales of the published studies. We used spatial and statistical modeling techniques to analyze and forecast fine scale spatial (2000 m grid and temporal (weekly patterns of West Nile virus mosquito infection relative to changing weather conditions in the urban landscape of the greater Chicago, Illinois, region for the years from 2004 to 2008. Results Increased air temperature was the strongest temporal predictor of increased infection in Culex pipiens and Culex restuans mosquitoes, with cumulative high temperature differences being a key factor distinguishing years with higher mosquito infection and higher human illness rates from those with lower rates. Drier conditions in the spring followed by wetter conditions just prior to an increase in infection were factors in some but not all years. Overall, 80% of the weekly variation in mosquito infection was explained by prior weather conditions. Spatially, lower precipitation was the most important variable predicting stronger mosquito infection; precipitation and temperature alone could explain the pattern of spatial variability better than could other environmental variables (79% explained in the best model. Variables related to impervious surfaces and elevation differences were of modest importance in the spatial model. Conclusion Finely grained temporal and spatial patterns of precipitation and air temperature have a consistent and significant impact on the timing and location of increased mosquito infection in the northeastern Illinois study area. The use of local weather data at multiple monitoring locations and the integration of mosquito

  11. Vírus do Nilo Ocidental: nova ameaça à segurança transfusional? West Nile virus: a new threat to transfusion safety?

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    Audrey K. Zeinad

    2004-01-01

    Full Text Available O vírus do Nilo Ocidental (West Nile Virus é um RNA vírus, dos mais importantes flavivírus patogênicos em humanos. Devido ao número crescente de casos confirmados de infeção pelo vírus do Nilo Ocidental nos EUA a partir de 1999, com a documentação da sua disseminação da costa leste para a oeste e sul em um período inferior a três anos e pela sua disseminação em quatro continentes, medidas estão sendo implementadas para o controle dessa epidemia. A documentação da transmissão pela transfusão de sangue, órgãos transplantados, aleitamento materno e transmissão vertical e a observação de taxa significante de morbidade e mortalidade (variando de 4% a 29% está alarmando a comunidade médica internacional. Esforços estão sendo realizados na tentativa de obtenção de testes diagnósticos precisos, na busca de uma terapêutica eficaz - uma vez que o meio de controle mais efetivo no momento é o controle de vetores (insetos - e no desenvolvimento de vacinas. Tendo em vista a detecção de casos na América Central e pelas condições climáticas ideais do Brasil, devemos estar atentos quanto aos possíveis riscos dessa epidemia. Esse artigo apresenta o quadro atual mundial de disseminação, modos de transmissão, quadro clínico, diagnóstico e tratamento, e algumas medidas preventivas para o controle do vírus do Nilo Ocidental.The West Nile virus is an RNA virus and is one of the most important pathogenic flaviviruses in humans. Due to the increasing number of confirmed cases in the U.S.A since 1999, with documentation of its dissemination from the East coast to the West and South in less than three years and because of its spread over four continents, measures are being implemented to control this epidemic. The documented transmission through blood transfusion, transplanted organs, breast feeding and vertical transmission and the significant morbidity and mortality rates (4 to 29% is alarming the international medical

  12. Neuromuscular Manifestations of West Nile Virus Infection

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    A. Arturo eLeis

    2012-03-01

    Full Text Available The most common neuromuscular manifestation of West Nile virus (WNV infection is a poliomyelitis syndrome with asymmetric paralysis variably involving one (monoparesis to four limbs (quadriparesis, with or without brainstem involvement and respiratory failure. This syndrome of acute flaccid paralysis may occur without overt fever or meningoencephalitis. Although involvement of anterior horn cells in the spinal cord and motor neurons in the brainstem are the major sites of pathology responsible for neuromuscular signs, inflammation also may involve skeletal or cardiac muscle (myositis, myocarditis, motor axons (polyradiculitis, peripheral nerve (Guillain-Barré syndrome, brachial plexopathy. In addition, involvement of spinal sympathetic neurons and ganglia provides a plausible explanation for autonomic instability seen in some patients. Many patients also experience prolonged subjective generalized weakness and disabling fatigue. Despite recent evidence that WNV may persist long term in the central nervous system or periphery in animals, the evidence in humans is controversial. WNV persistence would be of great concern in immunosuppressed patients or in those with prolonged or recurrent symptoms. Support for the contention that WNV can lead to autoimmune disease arises from reports of patients presenting with various neuromuscular diseases that presumably involve autoimmune mechanisms (GBS, other demyelinating neu¬ropathies, myasthenia gravis, brachial plexopathies, stiff-person syndrome, and delayed or recurrent symptoms. Although there is no specific treatment or vaccine currently approved in humans, and the standard remains supportive care, drugs that can alter the cascade of immunobiochemical events leading to neuronal death may be potentially useful (high-dose corticosteroids, interferon preparations, and intravenous immune globulin containing WNV-specific antibodies. Human experience with these agents seems promising based on anecdotal

  13. Trends in Hepatitis B Virus Seroprevalence in Black Sea Region

    African Journals Online (AJOL)

    2018-02-07

    Feb 7, 2018 ... the seroprevalence of hepatitis B among all age groups in northern Turkey using HBsAg and anti-HBs serological markers. Materials and Methods: .... in human serum or plasma, with a total incubation time of 18 min. All the ...

  14. Seroprevalence of antibodies against highly pathogenic avian influenza A (H5N1 virus among poultry workers in Bangladesh, 2009.

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    Sharifa Nasreen

    Full Text Available We conducted a cross-sectional study in 2009 to determine the seroprevalence and risk factors for highly pathogenic avian influenza A (H5N1 [HPAI H5N1] virus antibodies among poultry workers at farms and live bird markets with confirmed/suspected poultry outbreaks during 2009 in Bangladesh. We tested sera by microneutralization assay using A/Bangladesh/207095/2008 (H5N1; clade 2.2.2 virus with confirmation by horse red blood cell hemagglutination inhibition and H5-specific Western blot assays. We enrolled 212 workers from 87 farms and 210 workers from three live bird markets. One hundred and two farm workers (48% culled poultry. One hundred and ninety-three farm workers (91% and 178 market workers (85% reported direct contact with poultry that died during a laboratory confirmed HPAI H5N1 poultry farm outbreak or market poultry die-offs from suspected HPAI H5N1. Despite exposure to sick poultry, no farm or market poultry workers were seropositive for HPAI H5N1 virus antibodies (95% confidence interval 0-1%.

  15. Sero-prevalence study of bluetongue infection in sheep and goats in ...

    African Journals Online (AJOL)

    Bluetongue is an infectious, a non-contagious, arthropod borne viral disease of ruminants and has been reported from most of the tropical and subtropical regions of the world. Seroprevalence study was carried from July, 2013 to January, 2015 to understand bluetongue virus infection in selected areas of sheep and

  16. Identification and characterization of a virus-specific continuous B-cell epitope on the PrM/M protein of Japanese Encephalitis Virus: potential application in the detection of antibodies to distinguish Japanese Encephalitis Virus infection from West Nile Virus and Dengue Virus infections

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    Liu Wen-Xin

    2010-09-01

    Full Text Available Abstract Background Differential diagnose of Japanese encephalitis virus (JEV infection from other flavivirus especially West Nile virus (WNV and Dengue virus (DV infection was greatly hindered for the serological cross-reactive. Virus specific epitopes could benefit for developing JEV specific antibodies detection methods. To identify the JEV specific epitopes, we fully mapped and characterized the continuous B-cell epitope of the PrM/M protein of JEV. Results To map the epitopes on the PrM/M protein, we designed a set of 20 partially overlapping fragments spanning the whole PrM, fused them with GST, and expressed them in an expression vector. Linear epitope M14 (105VNKKEAWLDSTKATRY120 was detected by enzyme-linked immunosorbent assay (ELISA. By removing amino acid residues individually from the carboxy and amino terminal of peptide M14, we confirmed that the minimal unit of the linear epitope of PrM/M was M14-13 (108KEAWLDSTKAT118. This epitope was highly conserved across different JEV strains. Moreover, this epitope did not cross-react with WNV-positive and DENV-positive sera. Conclusion Epitope M14-13 was a JEV specific lineal B-cell epitpe. The results may provide a useful basis for the development of epitope-based virus specific diagnostic clinical techniques.

  17. West Nile Virus Encephalitis in a Patient with Neuroendocrine Carcinoma

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    Romina Deldar

    2016-01-01

    Full Text Available Importance. Oftentimes, when patients with metastatic cancer present with acute encephalopathy, it is suspected to be secondary to their underlying malignancy. However, there are multiple causes of delirium such as central nervous system (CNS infections, electrolyte abnormalities, and drug adverse reactions. Because West Nile Virus (WNV neuroinvasive disease has a high mortality rate in immunosuppressed patients, a high index of suspicion is required in patients who present with fever, altered mental status, and other neurological symptoms. Observations. Our case report details a single patient with brain metastases who presented with unexplained fever, encephalopathy, and new-onset tremors. Initially, it was assumed that his symptoms were due to his underlying malignancy or seizures. However, because his unexplained fevers persisted, lumbar puncture was pursued. Cerebrospinal fluid analysis included WNV polymerase chain reaction and serologies were ordered which eventually led to diagnosis of WNV encephalitis. Conclusions and Relevance. Patients with metastatic cancer who present with encephalopathy are often evaluated with assumption that malignancy is the underlying etiology. This can lead to delays in diagnosis and possible mistreatment. Our case highlights the importance of maintaining a broad differential diagnosis and an important diagnostic consideration of WNV encephalitis in patients with cancer.

  18. Survey for West Nile virus antibodies in wild ducks, 2004-06, USA

    Science.gov (United States)

    Hofmeister, Erik K.; Jankowski, Mark D.; Goldberg, Diana R.; Franson, J. Christian

    2016-01-01

    Detection of West Nile virus (WNV) in ducks has been reported in North America in isolated cases of mortality in wild waterbirds and following outbreaks in farmed ducks. Although the virus has been noted as an apparent incidental finding in several species of ducks, little is known about the prevalence of exposure or the outcome of infection with WNV in wild ducks in North America. From 2004–06, we collected sera from 1,406 wild-caught American Wigeon (Anas americana), Mallard (Anas platyrhynchos), and Northern Pintail (Anas acuta) ducks at national wildlife refuges (NWRs) in North Dakota and Wood Ducks (Aix sponsa) at NWRs in South Carolina and Tennessee. We measured the prevalence of previous exposure to WNV in these ducks by measuring WNV antibodies and evaluated variation in exposure among species, age, and year. Additionally, we evaluated the performance of a commercial antibody to wild bird immunoglobulin in duck species that varied in their phylogenetic relatedness to the bird species the antibody was directed against. As determined by a screening immunoassay and a confirmatory plaque reduction neutralization assay, the prevalence of WNV antibody was 10%. In light of experimental studies that show ducks to be relatively resistant to mortality caused by WNV, the antibody prevalence we detected suggests that wild ducks may be less-frequently exposed to WNV than expected for birds inhabiting wetlands where they may acquire infection from mosquitoes.

  19. Feeding patterns of potential West Nile virus vectors in south-west Spain.

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    Joaquín Muñoz

    Full Text Available Mosquito feeding behaviour determines the degree of vector-host contact and may have a serious impact on the risk of West Nile virus (WNV epidemics. Feeding behaviour also interacts with other biotic and abiotic factors that affect virus amplification and transmission.We identified the origin of blood meals in five mosquito species from three different wetlands in SW Spain. All mosquito species analysed fed with different frequencies on birds, mammals and reptiles. Both 'mosquito species' and 'locality' explained a similar amount of variance in the occurrence of avian blood meals. However, 'season of year' was the main factor explaining the presence of human blood meals. The differences in diet resulted in a marked spatial heterogeneity in the estimated WNV transmission risk. Culex perexiguus, Cx. modestus and Cx. pipiens were the main mosquito species involved in WNV enzootic circulation since they feed mainly on birds, were abundant in a number of localities and had high vector competence. Cx. perexiguus may also be important for WNV transmission to horses, as are Cx. pipiens and Cx. theileri in transmission to humans. Estimates of the WNV transmission risk based on mosquito diet, abundance and vector competence matched the results of previous WNV monitoring programs in the area. Our sensitivity analyses suggested that mosquito diet, followed by mosquito abundance and vector competence, are all relevant factors in understanding virus amplification and transmission risk in the studied wild ecosystems. At some of the studied localities, the risk of enzootic circulation of WNV was relatively high, even if the risk of transmission to humans and horses was less.Our results describe for first time the role of five WNV candidate vectors in SW Spain. Interspecific and local differences in mosquito diet composition has an important effect on the potential transmission risk of WNV to birds, horses and humans.

  20. 4EBP-Dependent Signaling Supports West Nile Virus Growth and Protein Expression.

    Science.gov (United States)

    Shives, Katherine D; Massey, Aaron R; May, Nicholas A; Morrison, Thomas E; Beckham, J David

    2016-10-18

    West Nile virus (WNV) is a (+) sense, single-stranded RNA virus in the Flavivirus genus. WNV RNA possesses an m7 GpppN m 5' cap with 2'- O -methylation that mimics host mRNAs preventing innate immune detection and allowing the virus to translate its RNA genome through the utilization of cap-dependent translation initiation effectors in a wide variety of host species. Our prior work established the requirement of the host mammalian target of rapamycin complex 1 (mTORC1) for optimal WNV growth and protein expression; yet, the roles of the downstream effectors of mTORC1 in WNV translation are unknown. In this study, we utilize gene deletion mutants in the ribosomal protein kinase called S6 kinase (S6K) and eukaryotic translation initiation factor 4E-binding protein (4EBP) pathways downstream of mTORC1 to define the role of mTOR-dependent translation initiation signals in WNV gene expression and growth. We now show that WNV growth and protein expression are dependent on mTORC1 mediated-regulation of the eukaryotic translation initiation factor 4E-binding protein/eukaryotic translation initiation factor 4E-binding protein (4EBP/eIF4E) interaction and eukaryotic initiation factor 4F (eIF4F) complex formation to support viral growth and viral protein expression. We also show that the canonical signals of mTORC1 activation including ribosomal protein s6 (rpS6) and S6K phosphorylation are not required for WNV growth in these same conditions. Our data suggest that the mTORC1/4EBP/eIF4E signaling axis is activated to support the translation of the WNV genome.

  1. 4EBP-Dependent Signaling Supports West Nile Virus Growth and Protein Expression

    Directory of Open Access Journals (Sweden)

    Katherine D. Shives

    2016-10-01

    Full Text Available West Nile virus (WNV is a (+ sense, single-stranded RNA virus in the Flavivirus genus. WNV RNA possesses an m7GpppNm 5′ cap with 2′-O-methylation that mimics host mRNAs preventing innate immune detection and allowing the virus to translate its RNA genome through the utilization of cap-dependent translation initiation effectors in a wide variety of host species. Our prior work established the requirement of the host mammalian target of rapamycin complex 1 (mTORC1 for optimal WNV growth and protein expression; yet, the roles of the downstream effectors of mTORC1 in WNV translation are unknown. In this study, we utilize gene deletion mutants in the ribosomal protein kinase called S6 kinase (S6K and eukaryotic translation initiation factor 4E-binding protein (4EBP pathways downstream of mTORC1 to define the role of mTOR-dependent translation initiation signals in WNV gene expression and growth. We now show that WNV growth and protein expression are dependent on mTORC1 mediated-regulation of the eukaryotic translation initiation factor 4E-binding protein/eukaryotic translation initiation factor 4E-binding protein (4EBP/eIF4E interaction and eukaryotic initiation factor 4F (eIF4F complex formation to support viral growth and viral protein expression. We also show that the canonical signals of mTORC1 activation including ribosomal protein s6 (rpS6 and S6K phosphorylation are not required for WNV growth in these same conditions. Our data suggest that the mTORC1/4EBP/eIF4E signaling axis is activated to support the translation of the WNV genome.

  2. Seroprevalence of bluetongue disease in sheep in west and northwest provinces of Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Khezri

    2013-09-01

    Full Text Available The objective of this study was to describe the seroprevalence rates of bluetongue virus (BTV in sheep in west and northwest provinces of Iran. Bluetongue virus, an economically important orbivirus of the Reoviridae family, causes a hemorrhagic disease mainly in sheep and occasionally in cattle and some species of deer. Bluetongue virus is transmitted between its mammalian hosts by certain species of biting midges (Culicoides spp. and it can infect all ruminant species. Overall, 26 serotypes have been reported around the world. Due to its economic impact, bluetongue (BT is an Office of International des Epizooties (OIE-listed disease. A total of 756 sera samples collected during 2007-2008, were available. Sera were tested with competitive enzyme-linked immunosorbent assay (C-ELISA. The seroprevalence rate in sheep was 40.87%. The rate of positivity in sheep in west and northwest was 46.10% and 33.75%, respectively. The highest prevalence of antibodies in serum was in West Azerbaijan (64.86%, and lower was in Ardabil (23.77%.

  3. Epidemic Spread of Usutu Virus in Southwest Germany in 2011 to 2013 and Monitoring of Wild Birds for Usutu and West Nile Viruses.

    Science.gov (United States)

    Ziegler, Ute; Jöst, Hanna; Müller, Kerstin; Fischer, Dominik; Rinder, Monika; Tietze, Dieter Thomas; Danner, Klaus-Jürgen; Becker, Norbert; Skuballa, Jasmin; Hamann, Hans-Peter; Bosch, Stefan; Fast, Christine; Eiden, Martin; Schmidt-Chanasit, Jonas; Groschup, Martin H

    2015-08-01

    Mosquito-borne viruses are becoming an increasing threat for Europe. One of these viruses is Usutu virus (USUV), a single-stranded RNA virus belonging to the Japanese encephalitis virus group within the family Flaviviridae. Since the occurrence of USUV among wild birds in June, 2011, infected Blackbirds (Turdus merula) have frequently been found dead in southwest Germany, cumulating in a massive die-off. Moreover, other bird species (Strigiformes) in this region have been affected. In a first study, 209 of over 600 dead birds (wild birds and birds kept in aviaries) collected from 2011 to 2013 carried USUV, more than 88% of them Blackbirds. USUV had already been detected in 2010, one year before the epizooty, in a mosquito-based surveillance program in Germany. The main epidemic area of the USUV outbreak in wild birds in southwest Germany has been similar for the last three years. In a second study during 2011 to 2013, 902 live migratory and resident birds (representing 87 bird species belonging to 14 bird orders) from four different sampling sites were bled and tested serologically and by qPCR for West Nile virus (WNV) and USUV infections. No USUV or WNV genomes were detected. Some migratory birds (mainly long-distance migrants and some partial migrants) carried neutralizing antibodies against WNV as discriminated by USUV and WNV cross-neutralization tests. Only few resident birds showed relevant USUV-specific neutralizing antibodies. The occurrence of USUV in the Upper Rhine valley area of southwest Germany is a proof of principle for the incursion and spread of other arthropod-borne (arbo)-viruses along these routes. Therefore, monitoring studies in birds and mosquitoes for the presence of arboviruses in these areas are indispensable.

  4. The impact of West Nile virus on the abundance of selected North American birds

    Directory of Open Access Journals (Sweden)

    Beard Raphaelle H

    2011-08-01

    Full Text Available Abstract Background The emergence of West Nile virus (WNV in North America has been associated with high mortality in the native avifauna and has raised concerns about the long-term impact of WNV on bird populations. Here, we present results from a longitudinal analysis of annual counts of six bird species, using North American Breeding Bird Survey data from ten states (1994 to 2010. We fit overdispersed Poisson models to annual counts. Counts from successive years were linked by an autoregressive process that depended on WNV transmission intensity (annual West Nile neuroinvasive disease reports and was adjusted by El Niño Southern Oscillation events. These models were fit using a Markov chain Monte Carlo algorithm. Results Model fit was mostly excellent, especially for American Crows, for which our models explained between 26% and 81% of the observed variance. The impact of WNV on bird populations was quantitatively evaluated by contrasting hypothetical count trajectories (omission of WNV with observed counts. Populations of American crows were most consistently affected with a substantial cumulative impact in six of ten states. The largest negative impact, almost 60%, was found in Illinois. A regionally substantial decline was also seen for American Robins and House Sparrows, while the other species appeared unaffected. Conclusions Our results confirm findings from previous studies that single out American Crows as the species most vulnerable to WNV infection. We discuss strengths and limitations of this and other methods for quantifying the impact of WNV on bird populations.

  5. Determination of the seroprevalence of Newcastle disease virus (avian paramyxovirus type 1 in Zambian backyard chicken flocks

    Directory of Open Access Journals (Sweden)

    Chimuka Musako

    2012-02-01

    Full Text Available A cross-sectional study was conducted in five provinces and 11 districts of Zambia to determine the seroprevalence of Newcastle disease in Zambian backyard chicken flocks. Of the chickens sampled, 73.9% tested positive for avian paramyxovirus type 1 antibodies by means of an enzyme-linked immunosorbent assay. Seroprevalence varied amongst the five provinces sampled, ranging from 82.6% in the Eastern Province to 48.3% in Luapula Province. Seroprevalence also varied amongst the 11 districts sampled, ranging from 91.3% in Monze district of Southern Province to 22.8% in Mufulira district of the Copperbelt province. Overall, the seroprevalence of Newcastle disease in Zambian backyard chicken flocks has increased since the previous study conducted in 1994.

  6. Variability in seroprevalence of rabies virus neutralizing antibodies and associated factors in a Colorado population of big brown bats (Eptesicus fuscus)

    Science.gov (United States)

    O’Shea, Thomas J.; Bowen, Richard A.; Stanley, Thomas R.; Shankar, Vidya; Rupprecht, Charles E.

    2014-01-01

    In 2001–2005 we sampled permanently marked big brown bats (Eptesicus fuscus) at summer roosts in buildings at Fort Collins, Colorado, for rabies virus neutralizing antibodies (RVNA). Seroprevalence was higher in adult females (17.9%, n = 2,332) than males (9.4%, n = 128; P = 0.007) or volant juveniles (10.2%, n = 738; Prabies viral RNA in oropharyngeal secretions of 261 seropositive bats or in organs of 13 euthanized seropositive bats. Survival of seropositive and seronegative bats did not differ. The presence of RVNA in serum of bats should not be interpreted as evidence for ongoing rabies infection.

  7. The common coot as sentinel species for the presence of West Nile and Usutu flaviviruses in Central Europe

    Czech Academy of Sciences Publication Activity Database

    Straková, Petra; Šikutová, Silvie; Jedličková, Petra; Sitko, J.; Rudolf, Ivo; Hubálek, Zdeněk

    2015-01-01

    Roč. 102, October (2015), s. 159-161 ISSN 0034-5288 EU Projects: European Commission(XE) 261504 Institutional support: RVO:68081766 Keywords : West Nile virus * Usutu virus * Common coot * Fulica atra * Surveillance * Mosquito -borne viruses * Culex spp. Subject RIV: EG - Zoology Impact factor: 1.504, year: 2015

  8. Serologic survey of birds for West Nile Flavivirus in Southern Moravia (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Halouzka, Jiří; Juřicová, Zina; Šikutová, Silvie; Rudolf, Ivo; Honza, Marcel; Janková, J.; Chytil, J.; Marec, František; Sitko, J.

    2008-01-01

    Roč. 8, č. 3 (2008), s. 659-666 ISSN 1530-3667 R&D Projects: GA AV ČR IAA600930611 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519; CEZ:AV0Z50070508 Source of funding: R - rámcový projekt EK Keywords : virus West Nile * virus Usutu * Flaviviridae * mosquito -borne viruses * birds Subject RIV: EE - Microbiology, Virology Impact factor: 2.195, year: 2008

  9. Effect of West Nile virus DNA-plasmid vaccination on response to live virus challenge in red-tailed hawks (Buteo jamaicensis).

    Science.gov (United States)

    Redig, Patrick T; Tully, Thomas N; Ritchie, Branson W; Roy, Alma F; Baudena, M Alexandra; Chang, Gwong-Jen J

    2011-08-01

    To evaluate the safety and efficacy of an experimental adjuvanted DNA-plasmid vaccine against West Nile virus (WNV) in red-tailed hawks (Buteo jamaicensis). 19 permanently disabled but otherwise healthy red-tailed hawks of mixed ages and both sexes without detectable serum antibodies against WNV. Hawks were injected IM with an experimental WNV DNA-plasmid vaccine in an aluminum-phosphate adjuvant (n = 14) or with the adjuvant only (control group; 5). All birds received 2 injections at a 3-week interval. Blood samples for serologic evaluation were collected before the first injection and 4 weeks after the second injection (day 0). At day 0, hawks were injected SC with live WNV. Pre- and postchallenge blood samples were collected at intervals for 14 days for assessment of viremia and antibody determination; oropharyngeal and cloacal swabs were collected for assessment of viral shedding. Vaccination was not associated with morbidity or deaths. Three of the vaccinated birds seroconverted after the second vaccine injection; all other birds seroconverted following the live virus injection. Vaccinated birds had significantly less severe viremia and shorter and less-intense shedding periods, compared with the control birds. Use of the WNV DNA-plasmid vaccine in red-tailed hawks was safe, and vaccination attenuated but did not eliminate both the viremia and the intensity of postchallenge shedding following live virus exposure. Further research is warranted to conclusively determine the efficacy of this vaccine preparation for protection of red-tailed hawks and other avian species against WNV-induced disease.

  10. Hepatitis A seroprevalence in patients with chronic viral hepatitis in Konya, Turkey.

    Science.gov (United States)

    Özden, Hale T

    2016-03-01

    Hepatitis A is among the diseases that can be prevented with vaccination in our time. Acute hepatitis A progresses more severely in individuals with a liver disease. Therefore, patients with a chronic liver disease (because of hepatitis B or hepatitis C) are advised vaccination with the hepatitis A vaccine. This study is aimed to determine the seroprevalence of hepatitis A virus (HAV) antibodies in patients infected with hepatitis C virus or hepatitis B virus in Konya province of Turkey. A total of 537 patients who had chronic viral hepatitis between January 2011 and December 2014 were included in the study. Serum samples were collected from each patient and tested for anti-HAV using the chemiluminescent microparticle immunoassay. The overall seroprevalence of total anti-HAV IgG was 94.2%. The overall prevalence of anti-HAV IgG in patients with chronic hepatitis B virus and hepatitis C virus infection was 97.5 and 93.6%, respectively. Anti-HAV IgG positivity was 97.4% in cirrhotic patients and 93.9% in noncirrhotic individuals. At the end of the study, being older than 40 years and living in a rural area were found to be independent risk factors for anti-HAV IgG seropositivity. In conclusion, we recommend that patients younger than 40 years and/or those living in cities and having a chronic liver disease should be vaccinated with the hepatitis A vaccine.

  11. Hepatitis A seroprevalence in patients with chronic viral hepatitis in Konya, Turkey

    Science.gov (United States)

    2016-01-01

    Aim Hepatitis A is among the diseases that can be prevented with vaccination in our time. Acute hepatitis A progresses more severely in individuals with a liver disease. Therefore, patients with a chronic liver disease (because of hepatitis B or hepatitis C) are advised vaccination with the hepatitis A vaccine. This study is aimed to determine the seroprevalence of hepatitis A virus (HAV) antibodies in patients infected with hepatitis C virus or hepatitis B virus in Konya province of Turkey. Methods A total of 537 patients who had chronic viral hepatitis between January 2011 and December 2014 were included in the study. Serum samples were collected from each patient and tested for anti-HAV using the chemiluminescent microparticle immunoassay. Results The overall seroprevalence of total anti-HAV IgG was 94.2%. The overall prevalence of anti-HAV IgG in patients with chronic hepatitis B virus and hepatitis C virus infection was 97.5 and 93.6%, respectively. Anti-HAV IgG positivity was 97.4% in cirrhotic patients and 93.9% in noncirrhotic individuals. Conclusion At the end of the study, being older than 40 years and living in a rural area were found to be independent risk factors for anti-HAV IgG seropositivity. In conclusion, we recommend that patients younger than 40 years and/or those living in cities and having a chronic liver disease should be vaccinated with the hepatitis A vaccine. PMID:26703930

  12. Preclinical and Clinical Development of a YFV 17 D-Based Chimeric Vaccine against West Nile Virus

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    Gustavo H. Dayan

    2013-12-01

    Full Text Available Substantial success has been achieved in the development and implementation of West Nile (WN vaccines for horses; however, no human WN vaccines are approved. This review focuses on the construction, pre-clinical and clinical characterization of ChimeriVax-WN02 for humans, a live chimeric vaccine composed of a yellow fever (YF 17D virus in which the prM-E envelope protein genes are replaced with the corresponding genes of the WN NY99 virus. Pre-clinical studies demonstrated that ChimeriVax-WN02 was significantly less neurovirulent than YF 17D in mice and rhesus and cynomolgus monkeys. The vaccine elicited neutralizing antibody titers after inoculation in hamsters and monkeys and protected immunized animals from lethal challenge including intracerebral inoculation of high dose of WN NY99 virus. Safety, viremia and immunogenicity of ChimeriVax-WN02 were assessed in one phase I study and in two phase II clinical trials. No safety signals were detected in the three clinical trials with no remarkable differences in incidence of adverse events (AEs between vaccine and placebo recipients. Viremia was transient and the mean viremia levels were low. The vaccine elicited strong and durable neutralizing antibody and cytotoxic T cell responses. WN epidemiology impedes a classical licensure pathway; therefore, innovative licensure strategies should be explored.

  13. The costs of infection and resistance as determinants of West Nile virus susceptibility in Culex mosquitoes

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    Styer Linda M

    2011-10-01

    Full Text Available Abstract Background Understanding the phenotypic consequences of interactions between arthropod-borne viruses (arboviruses and their mosquito hosts has direct implications for predicting the evolution of these relationships and the potential for changes in epidemiological patterns. Although arboviruses are generally not highly pathogenic to mosquitoes, pathology has at times been noted. Here, in order to evaluate the potential costs of West Nile virus (WNV infection and resistance in a primary WNV vector, and to assess the extent to which virus-vector relationships are species-specific, we performed fitness studies with and without WNV exposure using a highly susceptible Culex pipiens mosquito colony. Specifically, we measured and compared survival, fecundity, and feeding rates in bloodfed mosquitoes that were (i infected following WNV exposure (susceptible, (ii uninfected following WNV exposure (resistant, or (iii unexposed. Results In contrast to our previous findings with a relatively resistant Cx. tarsalis colony, WNV infection did not alter fecundity or blood-feeding behaviour of Cx. pipiens, yet results do indicate that resistance to infection is associated with a fitness cost in terms of mosquito survival. Conclusions The identification of species-specific differences provides an evolutionary explanation for variability in vector susceptibility to arboviruses and suggests that understanding the costs of infection and resistance are important factors in determining the potential competence of vector populations for arboviruses.

  14. The Immune Responses of the Animal Hosts of West Nile Virus: A Comparison of Insects, Birds, and Mammals

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    Laura R. H. Ahlers

    2018-04-01

    Full Text Available Vector-borne diseases, including arboviruses, pose a serious threat to public health worldwide. Arboviruses of the flavivirus genus, such as Zika virus (ZIKV, dengue virus, yellow fever virus (YFV, and West Nile virus (WNV, are transmitted to humans from insect vectors and can cause serious disease. In 2017, over 2,000 reported cases of WNV virus infection occurred in the United States, with two-thirds of cases classified as neuroinvasive. WNV transmission cycles through two different animal populations: birds and mosquitoes. Mammals, particularly humans and horses, can become infected through mosquito bites and represent dead-end hosts of WNV infection. Because WNV can infect diverse species, research on this arbovirus has investigated the host response in mosquitoes, birds, humans, and horses. With the growing geographical range of the WNV mosquito vector and increased human exposure, improved surveillance and treatment of the infection will enhance public health in areas where WNV is endemic. In this review, we survey the bionomics of mosquito species involved in Nearctic WNV transmission. Subsequently, we describe the known immune response pathways that counter WNV infection in insects, birds, and mammals, as well as the mechanisms known to curb viral infection. Moreover, we discuss the bacterium Wolbachia and its involvement in reducing flavivirus titer in insects. Finally, we highlight the similarities of the known immune pathways and identify potential targets for future studies aimed at improving antiviral therapeutic and vaccination design.

  15. Immune response to the West Nile virus in aged non-human primates.

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    Anne M Wertheimer

    2010-12-01

    Full Text Available Risk of encephalitis from West Nile virus (WNV infection increases dramatically with age. Understanding the basis of this susceptibility requires development of suitable animal models. Here, we investigated the immune response to WNV in old non-human primates.We investigated clinical, immunological and virological correlates of WNV infection in aging non-human primates. Aged (17-30 yrs and adult (6-9 yrs Rhesus macaques (RM were challenged with WNV in the presence or the absence of the mosquito salivary gland extract (SGE to approximate natural infection. None of the 26 animals exhibited clinical signs of the disease. Quantitative PCR suggested discrete and short-lived viremia, but infectious virus was never isolated. There was markedly increased, age-independent, proliferation of CD3(- non-B cells, followed by B-cell proliferation, which correlated to the loss of detectable WNV genomes. Moreover, animals primed with mosquito salivary gland extract exhibited reduced circulating WNV RNA. While we found the expected age-associated reduction in T cell proliferation, adaptive immunity did not correlate with infection outcome. That was further confirmed in a cohort of thymectomized and/or CD8 T-cell depleted Cynomolgus macaques (CM; N = 15, who also failed to develop WNV disease.Results are consistent with strong and age-independent innate resistance of macaques against WNV challenge. This animal model is therefore not suitable for vaccine and therapeutic testing against WNV. However, understanding the basis of their innate resistance against WNV in macaques could provide helpful clues to improve anti-WNV protection of older adults.

  16. West Nile virus replication requires fatty acid synthesis but is independent on phosphatidylinositol-4-phosphate lipids.

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    Miguel A Martín-Acebes

    Full Text Available West Nile virus (WNV is a neurovirulent mosquito-borne flavivirus, which main natural hosts are birds but it also infects equines and humans, among other mammals. As in the case of other plus-stranded RNA viruses, WNV replication is associated to intracellular membrane rearrangements. Based on results obtained with a variety of viruses, different cellular processes have been shown to play important roles on these membrane rearrangements for efficient viral replication. As these processes are related to lipid metabolism, fatty acid synthesis, as well as generation of a specific lipid microenvironment enriched in phosphatidylinositol-4-phosphate (PI4P, has been associated to it in other viral models. In this study, intracellular membrane rearrangements following infection with a highly neurovirulent strain of WNV were addressed by means of electron and confocal microscopy. Infection of WNV, and specifically viral RNA replication, were dependent on fatty acid synthesis, as revealed by the inhibitory effect of cerulenin and C75, two pharmacological inhibitors of fatty acid synthase, a key enzyme of this process. However, WNV infection did not induce redistribution of PI4P lipids, and PI4P did not localize at viral replication complex. Even more, WNV multiplication was not inhibited by the use of the phosphatidylinositol-4-kinase inhibitor PIK93, while infection by the enterovirus Coxsackievirus B5 was reduced. Similar features were found when infection by other flavivirus, the Usutu virus (USUV, was analyzed. These features of WNV replication could help to design specific antiviral approaches against WNV and other related flaviviruses.

  17. Does reservoir host mortality enhance transmission of West Nile virus?

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    Foppa Ivo M

    2007-05-01

    Full Text Available Abstract Background Since its 1999 emergence in New York City, West Nile virus (WNV has become the most important and widespread cause of mosquito-transmitted disease in North America. Its sweeping spread from the Atlantic to the Pacific coast was accompanied by widespread mortality among wild birds, especially corvids. Only sporadic avian mortality had previously been associated with this infection in the Old World. Here, we examine the possibility that reservoir host mortality may intensify transmission, both by concentrating vector mosquitoes on remaining hosts and by preventing the accumulation of "herd immunity". Results Inspection of the Ross-Macdonald expression of the basic reproductive number (R0 suggests that this quantity may increase with reservoir host mortality. Computer simulation confirms this finding and indicates that the level of virulence is positively associated with the numbers of infectious mosquitoes by the end of the epizootic. The presence of reservoir incompetent hosts in even moderate numbers largely eliminated the transmission-enhancing effect of host mortality. Local host die-off may prevent mosquitoes to "waste" infectious blood meals on immune host and may thus facilitate perpetuation and spread of transmission. Conclusion Under certain conditions, host mortality may enhance transmission of WNV and similarly maintained arboviruses and thus facilitate their emergence and spread. The validity of the assumptions upon which this argument is built need to be empirically examined.

  18. Inhibition of West Nile virus by calbindin-D28k.

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    Venkatraman Siddharthan

    Full Text Available Evidence indicates that West Nile virus (WNV employs Ca(2+ influx for its replication. Moreover, calcium buffer proteins, such as calbindin D28k (CB-D28k, may play an important role mitigating cellular destruction due to disease processes, and more specifically, in some neurological diseases. We addressed the hypothesis that CB-D28k inhibits WNV replication in cell culture and infected rodents. WNV envelope immunoreactivity (ir was not readily co-localized with CB-D28k ir in WNV-infected Vero 76 or motor neuron-like NSC34 cells that were either stably or transiently transfected with plasmids coding for CB-D28k gene. This was confirmed in cultured cells fixed on glass coverslips and by flow cytometry. Moreover, WNV infectious titers were reduced in CB-D28k-transfected cells. As in cell culture studies, WNV env ir was not co-localized with CB-D28k ir in the cortex of an infected WNV hamster, or in the hippocampus of an infected mouse. Motor neurons in the spinal cord typically do not express CB-D28k and are susceptible to WNV infection. Yet, CB-D28k was detected in the surviving motor neurons after the initial phase of WNV infection in hamsters. These data suggested that induction of CB-D28k elicit a neuroprotective response to WNV infection.

  19. Seroprevalence of human T-cell lymphotropic virus-1/2 in blood donors in northern pakistan: implication for blood donor screening

    International Nuclear Information System (INIS)

    Niazi, S.K.

    2015-01-01

    To determine the seroprevalence of Human T-cell Lymphotropic Virus-1/2 (HTLV-1/2) in blood donors in Northern Pakistan. Study Design: Descriptive study. Place and Duration of Study: Armed Forces Institute of Transfusion, Rawalpindi, from July to August 2013. Methodology:A total of 2100 blood donors were screened for anti-HTLV-1/2 antibodies during the study period, in a pool of six, on a highly sensitive, Chemiluminiscent Microparticle Immunoassay (CMIA) based system. The screening test reactive donors were recalled, counseled and interviewed, and a fresh sample was obtained for confirmatory testing. Confirmation was performed using additional immunoassays including Line Immunoassay (LIA); with additional testing for HTLV-1 pvDNAPCR. Frequency and percentages were determined. Results: Four donors (0.19%) were repeatedly screening test-reactive and were subsequently confirmed to be HTLV-1 infected by line immunoassay and HTLV-1 pvDNAPCR. All four donors were male with mean age of 27 ± 6.27 years. Two (50%) of the positive donors gave history of Multiple Sexual Partners (MSP). Conclusion: HTLV-1 seroprevalence in Northern Pakistan blood donors was determined to be 0.19%. Large scale studies, including the cost effectiveness of screening blood donations for anti-HTLV-1/2 in Pakistan, are recommended. (author)

  20. Construction of self-replicating subgenomic West Nile virus replicons for screening antiviral compounds.

    Science.gov (United States)

    Alcaraz-Estrada, Sofia L; Reichert, Erin Donohue; Padmanabhan, Radhakrishnan

    2013-01-01

    Mosquito-borne flavivirus RNA genomes encode one long open reading frame flanking 5'- and 3'-untranslated regions (5'- and 3'-UTRs) which contain cis-acting RNA elements playing important roles for viral RNA translation and replication. The viral RNA encodes a single polyprotein, which is processed into three structural proteins and seven nonstructural (NS) proteins. The regions coding for the seven NS proteins are sufficient for replication of the RNA. The sequences encoding the structural genes can be deleted except for two short regions. The first one encompasses 32 amino acid (aa) residues from the N-terminal coding sequence of capsid (C) and the second, 27 aa region from the C-terminus of envelope (E) protein. The deleted region can be substituted with a gene coding for a readily quantifiable reporter to give rise to a subgenomic reporter replicon. Replicons containing a variety of reporter genes and marker genes for construction of stable mammalian cell lines are valuable reagents for studying the effects of mutations in translation and/or replication in isolation from processes like the entry and assembly of the virus particles. Here we describe the construction of two West Nile virus (WNV) replicons by overlap extension PCR and standard recombinant DNA techniques. One has a Renilla luciferase (Rluc) reporter gene followed by an internal ribosome entry site (element) for cap-independent translation of the open reading frame encompassing the carboxy-terminal sequence of E to NS5. The second replicon has in tandem the Rluc gene, foot and mouth disease virus 2A, and neomycin phosphotransferase gene that allows establishment of a stable mammalian cell line expressing the Rluc reporter in the presence of the neomycin analog, G418. The stable replicon-expressing Vero cell line has been used for cell-based screening and determination of EC50 values for antiviral compounds that inhibited WNV replication.

  1. Experimental infection of cliff swallows (Petrochelidon pyrrhonota) with varying doses of West Nile virus

    Science.gov (United States)

    Oesterle, P.T.; Nemeth, N.M.; VanDalen, Kaci K.; Sullivan, H.; Bentler, K.T.; Young, G.R.; McLean, R.G.; Clark, L.; Smeraski, C.; Hall, Jeffrey S.

    2009-01-01

    Cliff swallows (Petrochelidon pyrrhonota) were inoculated with differing doses of West Nile virus (WNV) to evaluate their potential role as reservoir hosts in nature. Swallows often nest in large colonies in habitats and months associated with high mosquito abundance and early WNV transmission in North America. Additionally, cliff swallow diet consists of insects, including mosquitoes, leading to an additional potential route of WNV infection. The average peak viremia titer among infected cliff swallows was 106.3 plaque-forming units (PFU)/mL serum and the reservoir competence index was 0.34. There was no correlation between dose and probability of becoming infected or viremia peak and duration. Oral shedding was detected from 2 to 14 days post-inoculation with an average peak titer of 1044 PFU/swab. These results suggest that cliff swallows are competent reservoir hosts of WNV and therefore, they may play a role in early seasonal amplification and maintenance of WNV. Copyright ?? 2009 by The American Society of Tropical Medicine and Hygiene.

  2. West Nile Virus State of the Art Report of MALWEST Project

    Science.gov (United States)

    Marka, Andriani; Diamantidis, Alexandros; Papa, Anna; Valiakos, George; Chaintoutis, Serafeim C.; Doukas, Dimitrios; Tserkezou, Persefoni; Giannakopoulos, Alexios; Papaspyropoulos, Konstantinos; Patsoula, Eleni; Badieritakis, Evangelos; Baka, Agoritsa; Tseroni, Maria; Pervanidou, Danai; Papadopoulos, Nikos T.; Koliopoulos, George; Tontis, Dimitrios; Dovas, Chrysostomos I.; Billinis, Charalambos; Tsakris, Athanassios; Kremastinou, Jenny; Hadjichristodoulou, Christos

    2013-01-01

    During the last three years Greece is experiencing the emergence of West Nile virus (WNV) epidemics. Within this framework, an integrated surveillance and control programme (MALWEST project) with thirteen associate partners was launched aiming to investigate the disease and suggest appropriate interventions. One out of seven work packages of the project is dedicated to the State of the Art report for WNV. Three expert working groups on humans, animals and mosquitoes were established. Medical databases (PubMed, Scopus) were searched together with websites: e.g., WHO, CDC, ECDC. In total, 1,092 relevant articles were initially identified and 258 of them were finally included as references regarding the current knowledge about WNV, along with 36 additional sources (conference papers, reports, book chapters). The review is divided in three sections according to the fields of interest: (1) WNV in humans (epidemiology, molecular characteristics, transmission, diagnosis, treatment, prevention, surveillance); (2) WNV in animals (epidemiological and transmission characteristics concerning birds, horses, reptiles and other animal species) and (3) WNV in mosquitoes (control, surveillance). Finally, some examples of integrated surveillance programmes are presented. The introduction and establishment of the disease in Greece and other European countries further emphasizes the need for thorough research and broadening of our knowledge on this viral pathogen. PMID:24317379

  3. West Nile Virus State of the Art Report of MALWEST Project

    Directory of Open Access Journals (Sweden)

    Andriani Marka

    2013-12-01

    Full Text Available During the last three years Greece is experiencing the emergence of West Nile virus (WNV epidemics. Within this framework, an integrated surveillance and control programme (MALWEST project with thirteen associate partners was launched aiming to investigate the disease and suggest appropriate interventions. One out of seven work packages of the project is dedicated to the State of the Art report for WNV. Three expert working groups on humans, animals and mosquitoes were established. Medical databases (PubMed, Scopus were searched together with websites: e.g., WHO, CDC, ECDC. In total, 1,092 relevant articles were initially identified and 258 of them were finally included as references regarding the current knowledge about WNV, along with 36 additional sources (conference papers, reports, book chapters. The review is divided in three sections according to the fields of interest: (1 WNV in humans (epidemiology, molecular characteristics, transmission, diagnosis, treatment, prevention, surveillance; (2 WNV in animals (epidemiological and transmission characteristics concerning birds, horses, reptiles and other animal species and (3 WNV in mosquitoes (control, surveillance. Finally, some examples of integrated surveillance programmes are presented. The introduction and establishment of the disease in Greece and other European countries further emphasizes the need for thorough research and broadening of our knowledge on this viral pathogen.

  4. Rapid Identification of Dengue Virus Serotypes Using Monoclonal Antibodies in an Indirect Immunofluorescence Test.

    Science.gov (United States)

    1982-06-18

    encephalitis(TBH-28), West Nile(E-101), Yellow fever(French neurotropic and 17D strains), and Zika . Two Sandfly Fever viruses (213452 and Candiru) were...were provided as first passage isolates ( Aedes pseudoscutellaris cells, AP-61) or human serum from recent dengue virus patients. African isolates... viruses of the Phlebovirus genus (Table 1). Several monoclonal antibody preparations reacted solely with dengue virus serotypes. Two preparations (13E7 and

  5. Seroprevalence of Anti-Chikungunya Virus Antibodies in Children and Adults in Managua, Nicaragua, After the First Chikungunya Epidemic, 2014-2015.

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    Guillermina Kuan

    2016-06-01

    Full Text Available Chikungunya is a viral disease transmitted by Aedes aegypti and Ae. albopictus mosquitoes. In late 2013, chikungunya virus (CHIKV was introduced into the Caribbean island of St. Martin. Since then, approximately 2 million chikungunya cases have been reported by the Pan American Health Organization, and most countries in the Americas report autochthonous transmission of CHIKV. In Nicaragua, the first imported case was described in July 2014 and the first autochthonous case in September 2014. Here, we conducted two studies to analyze the seroprevalence of anti-CHIKV antibodies after the first chikungunya epidemic in a community-based cohort study (ages 2-14 years and in a cross-sectional survey of persons aged ≥15 years in the same area of Managua, Nicaragua. Routine annual serum samples collected from 3,362 cohort participants in March/April 2014 and 2015, and 848 age-stratified samples collected from persons ≥15 years old at the end of May-beginning of June 2015 were used to estimate the seroprevalence of anti-CHIKV antibodies after the first epidemic (October 2014 to February 2015 in the study population. Using an Inhibition ELISA assay that measures total anti-CHIKV antibodies, the seroprevalence was significantly higher in those aged ≥15 (13.1% (95%CI: 10.9, 15.5 than in the pediatric population (6.1% (95%CI: 5.3, 6.9. The proportion of inapparent infections was 58.3% (95%CI: 51.5, 65.1 in children and 64.9% (95%CI: 55.2, 73.7 in the ≥15 study population. We identified age, water availability, household size, and socioeconomic status as factors associated with the presence of anti-CHIKV antibodies. Overall, this is the first report of CHIKV seropositivity in continental Latin America and provides useful information for public health authorities in the region.

  6. Geographic Variability in Geocoding Success for West Nile Virus Cases in South Dakota

    Science.gov (United States)

    Wey, Christine L.; Griesse, Jennifer; Kightlinger, Lon; Wimberly, Michael C.

    2009-01-01

    Background Geocoding, the process of assigning each case a set of coordinates that closely approximates its true location, is an important component of spatial epidemiological studies. The failure to accurately geocode cases adversely affects the validity and strength of conclusions drawn from the analysis. We investigated whether there were differences among geographic locations and demographic classes in the ability to successfully geocode West Nile virus (WNV) cases in South Dakota. We successfully geocoded 1,354 cases (80.8%) to their street address locations and assigned all 1,676 cases to ZIP code tabulation areas (ZCTAs). Using spatial scan statistics, significant clusters of non-geocoded cases were identified in central and western South Dakota. Geocoding success rates were lower in areas of low population density and on Indian reservations than in other portions of the state. Geocoding success rates were lower for Native Americans than for other races. Spatial epidemiological studies should consider the potential biases that may result from excluding non-geocoded cases, particularly in rural portions of the Great Plains that contain large Native American populations. PMID:19577505

  7. Zika virus infection: a public health emergency!

    OpenAIRE

    Qureshi, Muhammad Salman Haider; Qureshi, Bakhtawar Wajeeha; Khan, Ramsha

    2017-01-01

    Zika virus belongs to the family of Flaviviridae. The Flaviviridae family also includes other human pathogens like West Nile virus (WNV), Yellow fever virus (YFV), mosquito transmitted Dengue virus (DENV), Tick borne encephalitic virus (TBEV) and Japanese encephalitis virus (JEV). Zika virus is a mosquito-borne disease and is transmitted by Aedes aegypti mosquito.

  8. Seroprevalence Dynamics of European Bat Lyssavirus Type 1 in a Multispecies Bat Colony

    Directory of Open Access Journals (Sweden)

    Marc López-Roig

    2014-09-01

    Full Text Available We report an active surveillance study of the occurrence of specific antibodies to European Bat Lyssavirus Type 1 (EBLV-1 in bat species, scarcely studied hitherto, that share the same refuge. From 2004 to 2012, 406 sera were obtained from nine bat species. Blood samples were subjected to a modified fluorescent antibody virus neutralization test to determine the antibody titer. EBLV-1-neutralizing antibodies were detected in six of the nine species analyzed (Pipistrellus pipistrellus, P. kuhlii, Hypsugo savii, Plecotus austriacus, Eptesicus serotinus and Tadarida teniotis. Among all bats sampled, female seroprevalence (20.21%, 95% CI: 14.78%–26.57% was not significantly higher than the seroprevalence in males (15.02%, 95% CI: 10.51%–20.54%. The results showed that the inter-annual variation in the number of seropositive bats in T. teniotis and P. austriacus showed a peak in 2007 (>70% of EBLV-1 prevalence. However, significant differences were observed in the temporal patterns of the seroprevalence modeling of T. teniotis and P. austriacus. The behavioral ecology of these species involved could explain the different annual fluctuations in EBLV-1 seroprevalence.

  9. Seroprevalence dynamics of European bat lyssavirus type 1 in a multispecies bat colony.

    Science.gov (United States)

    López-Roig, Marc; Bourhy, Hervé; Lavenir, Rachel; Serra-Cobo, Jordi

    2014-09-04

    We report an active surveillance study of the occurrence of specific antibodies to European Bat Lyssavirus Type 1 (EBLV-1) in bat species, scarcely studied hitherto, that share the same refuge. From 2004 to 2012, 406 sera were obtained from nine bat species. Blood samples were subjected to a modified fluorescent antibody virus neutralization test to determine the antibody titer. EBLV-1-neutralizing antibodies were detected in six of the nine species analyzed (Pipistrellus pipistrellus, P. kuhlii, Hypsugo savii, Plecotus austriacus, Eptesicus serotinus and Tadarida teniotis). Among all bats sampled, female seroprevalence (20.21%, 95% CI: 14.78%-26.57%) was not significantly higher than the seroprevalence in males (15.02%, 95% CI: 10.51%-20.54%). The results showed that the inter-annual variation in the number of seropositive bats in T. teniotis and P. austriacus showed a peak in 2007 (>70% of EBLV-1 prevalence). However, significant differences were observed in the temporal patterns of the seroprevalence modeling of T. teniotis and P. austriacus. The behavioral ecology of these species involved could explain the different annual fluctuations in EBLV-1 seroprevalence.

  10. Wolbachia enhances West Nile virus (WNV infection in the mosquito Culex tarsalis.

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    Brittany L Dodson

    2014-07-01

    Full Text Available Novel strategies are required to control mosquitoes and the pathogens they transmit. One attractive approach involves maternally inherited endosymbiotic Wolbachia bacteria. After artificial infection with Wolbachia, many mosquitoes become refractory to infection and transmission of diverse pathogens. We evaluated the effects of Wolbachia (wAlbB strain on infection, dissemination and transmission of West Nile virus (WNV in the naturally uninfected mosquito Culex tarsalis, which is an important WNV vector in North America. After inoculation into adult female mosquitoes, Wolbachia reached high titers and disseminated widely to numerous tissues including the head, thoracic flight muscles, fat body and ovarian follicles. Contrary to other systems, Wolbachia did not inhibit WNV in this mosquito. Rather, WNV infection rate was significantly higher in Wolbachia-infected mosquitoes compared to controls. Quantitative PCR of selected innate immune genes indicated that REL1 (the activator of the antiviral Toll immune pathway was down regulated in Wolbachia-infected relative to control mosquitoes. This is the first observation of Wolbachia-induced enhancement of a human pathogen in mosquitoes, suggesting that caution should be applied before releasing Wolbachia-infected insects as part of a vector-borne disease control program.

  11. Seroprevalence of mumps in The Netherlands: dynamics over a decade with high vaccination coverage and recent outbreaks.

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    Gaby Smits

    Full Text Available Here we present mumps virus specific antibody levels in a large cross-sectional population-based serosurveillance study performed in the Netherlands in 2006/2007 (n = 7900. Results were compared with a similar study (1995/1996 and discussed in the light of recent outbreaks. Mumps antibodies were tested using a fluorescent bead-based multiplex immunoassay. Overall seroprevalence was 90.9% with higher levels in the naturally infected cohorts compared with vaccinated cohorts. Mumps virus vaccinations at 14 months and 9 years resulted in an increased seroprevalence and antibody concentration. The second vaccination seemed to be important in acquiring stable mumps antibody levels in the long term. In conclusion, the Dutch population is well protected against mumps virus infection. However, we identified specific age- and population groups at increased risk of mumps infection. Indeed, in 2007/2008 an outbreak has occurred in the low vaccination coverage groups emphasizing the predictive value of serosurveillance studies.

  12. Seroprevalence of poliovirus antibodies in the Kansas City metropolitan area, 2012-2013.

    Science.gov (United States)

    Wallace, Gregory S; Pahud, Barbara A; Weldon, William C; Curns, Aaron T; Oberste, M Steven; Harrison, Christopher J

    2017-04-03

    No indigenous cases of poliomyelitis have occurred in the US since 1979; however the risk of importation persists until global eradication is achieved. The seropositivity rate for different age cohorts with exposures to different poliovirus vaccine types and wild virus in the US are not presently known. A convenience sample was conducted in the Kansas City metropolitan area during 2012-2103 with approximately 100 participants enrolled for each of 5 age cohorts categorized based on vaccine policy changes over time in the US. Immunization records for poliovirus vaccination were required for participants poliovirus serotypes. Seroprevalence was evaluated by demographics as well as between polio serotypes. The overall seroprevalence to poliovirus was 90.7%, 94.4%, and 83.3%, for types 1, 2, and 3, respectively. Seroprevalence was high (88.6%-96.2%) for all 3 types of poliovirus for the 6-10 y old age group that was likely to have received a complete schedule of IPV-only vaccination. Children 2-3 y of age, who have not yet completed their full IPV series, had lower seroprevalence compared with all older age groups for types 1 and 2 (p-value poliovirus in the population surveyed. Seroprevalence for subjects aged 2-3 y was lower than all other age groups for serotypes 1 and 2 highlighting the importance of completing the recommended poliovirus vaccine series with a booster dose at age 4-6 y.

  13. Use of Temperature to Improve West Nile Virus Forecasts

    Science.gov (United States)

    Shaman, J. L.; DeFelice, N.; Schneider, Z.; Little, E.; Barker, C.; Caillouet, K.; Campbell, S.; Damian, D.; Irwin, P.; Jones, H.; Townsend, J.

    2017-12-01

    Ecological and laboratory studies have demonstrated that temperature modulates West Nile virus (WNV) transmission dynamics and spillover infection to humans. Here we explore whether the inclusion of temperature forcing in a model depicting WNV transmission improves WNV forecast accuracy relative to a baseline model depicting WNV transmission without temperature forcing. Both models are optimized using a data assimilation method and two observed data streams: mosquito infection rates and reported human WNV cases. Each coupled model-inference framework is then used to generate retrospective ensemble forecasts of WNV for 110 outbreak years from among 12 geographically diverse United States counties. The temperature-forced model improves forecast accuracy for much of the outbreak season. From the end of July until the beginning of October, a timespan during which 70% of human cases are reported, the temperature-forced model generated forecasts of the total number of human cases over the next 3 weeks, total number of human cases over the season, the week with the highest percentage of infectious mosquitoes, and the peak percentage of infectious mosquitoes that were on average 5%, 10%, 12%, and 6% more accurate, respectively, than the baseline model. These results indicate that use of temperature forcing improves WNV forecast accuracy and provide further evidence that temperatures influence rates of WNV transmission. The findings help build a foundation for implementation of a statistically rigorous system for real-time forecast of seasonal WNV outbreaks and their use as a quantitative decision support tool for public health officials and mosquito control programs.

  14. Use of temperature to improve West Nile virus forecasts.

    Directory of Open Access Journals (Sweden)

    Nicholas B DeFelice

    2018-03-01

    Full Text Available Ecological and laboratory studies have demonstrated that temperature modulates West Nile virus (WNV transmission dynamics and spillover infection to humans. Here we explore whether inclusion of temperature forcing in a model depicting WNV transmission improves WNV forecast accuracy relative to a baseline model depicting WNV transmission without temperature forcing. Both models are optimized using a data assimilation method and two observed data streams: mosquito infection rates and reported human WNV cases. Each coupled model-inference framework is then used to generate retrospective ensemble forecasts of WNV for 110 outbreak years from among 12 geographically diverse United States counties. The temperature-forced model improves forecast accuracy for much of the outbreak season. From the end of July until the beginning of October, a timespan during which 70% of human cases are reported, the temperature-forced model generated forecasts of the total number of human cases over the next 3 weeks, total number of human cases over the season, the week with the highest percentage of infectious mosquitoes, and the peak percentage of infectious mosquitoes that on average increased absolute forecast accuracy 5%, 10%, 12%, and 6%, respectively, over the non-temperature forced baseline model. These results indicate that use of temperature forcing improves WNV forecast accuracy and provide further evidence that temperature influences rates of WNV transmission. The findings provide a foundation for implementation of a statistically rigorous system for real-time forecast of seasonal WNV outbreaks and their use as a quantitative decision support tool for public health officials and mosquito control programs.

  15. Epitope-blocking enzyme-linked immunosorbent assay to differentiate west nile virus from Japanese encephalitis virus infections in equine sera.

    Science.gov (United States)

    Kitai, Yoko; Shoda, Mizue; Kondo, Takashi; Konishi, Eiji

    2007-08-01

    West Nile virus (WNV) is now widely distributed worldwide, except in most areas of Asia where Japanese encephalitis virus (JEV) is distributed. Considering the movement and migration of reservoir birds, there is concern that WNV may be introduced in Asian countries. Although manuals and guidelines for serological tests have been created in Japan in preparedness for the introduction of WNV, differential diagnosis between WNV and JEV may be complicated by antigenic cross-reactivities between these flaviviruses. Here, we generated a monoclonal antibody specific for the nonstructural protein 1 (NS1) of WNV and established an epitope-blocking enzyme-linked immunosorbent assay that can differentiate WNV from JEV infections in horse sera. Under conditions well suited for our assay system, samples collected from 95 horses in Japan (regarded as negative for WNV antibodies), including those collected from horses naturally infected with JEV, showed a mean inhibition value of 8.2% and a standard deviation (SD) of 6.5%. However, inhibition values obtained with serum used as a positive control (obtained after 28 days from a horse experimentally infected with WNV) in nine separate experiments showed a mean of 54.4% and an SD of 7.1%. We tentatively determined 27.6% (mean + 3 x SD obtained with 95 negative samples) as the cutoff value to differentiate positive from negative samples. Under this criterion, two horses experimentally infected with WNV were diagnosed as positive at 12 and 14 days, respectively, after infection.

  16. Estimating seroprevalence of herpes simplex virus type 1 among different Middle East and North African male populations residing in Qatar

    Science.gov (United States)

    Nasrallah, Gheyath K.; Dargham, Soha R.; Mohammed, Layla I.

    2017-01-01

    HSV‐1 epidemiology in the Middle East and North Africa (MENA) remains poorly understood. Our study aimed to measure HSV‐1 antibody prevalence (seroprevalence) and its age‐distribution among select MENA populations residing in Qatar. Sera were collected from male blood donors attending Hamad Medical Corporation 2013‐2015. A total of 2,077 sera were tested for anti‐HSV‐1 antibodies using HerpeSelect® 1 ELISA IgG kits (Focus Diagnostics, Cypress, CA). Robust Poisson regression was conducted to estimate adjusted infection prevalence ratios. Country‐specific HSV‐1 seroprevalence was estimated for 10 national populations: 97.5% among Egyptians, 92.6% among Yemenis, 90.7% among Sudanese, 88.5% among Syrians, 86.5% among Jordanians, 82.3% among Qataris, 81.4% among Iranians, 81.4% among Lebanese, 80.5% among Palestinians, and 77.0% among Pakistanis. Age‐specific HSV‐1 seroprevalence was estimated for Egypt, the Fertile Crescent (Iraq, Jordan, Lebanon, Palestine, and Syria), and Qatar. Seroprevalence increased with age among Fertile Crescent and Qatari nationals. Seroprevalence increased from 70.0% among those aged ≤ 24 years up to 98.0% among those aged ≥55 years among Fertile Crescent nationals. Seroprevalence was consistently above 90% for all ages among Egyptians. HSV‐1 seroprevalence is high in MENA, though with some variation across countries. The seroprevalence appears to have declined among current young age cohorts compared to its levels a few decades ago. PMID:28817197

  17. Comparison of immune responses of brown-headed cowbird and related blackbirds to West Nile and other mosquito-borne encephalitis viruses

    Science.gov (United States)

    Reisen, W.K.; Hahn, D.C.

    2007-01-01

    The rapid geographic spread of West Nile virus (family Flaviviridae, genus Flavivirus, WNV) across the United States has stimulated interest in comparative host infection studies to delineate competent avian hosts critical for viral amplification. We compared the host competence of four taxonomically related blackbird species (Icteridae) after experimental infection with WNV and with two endemic, mosquito-borne encephalitis viruses, western equine encephalomyelitis virus (family Togaviridae, genus Alphavirus, WEEV), and St, Louis encephalitis virus (family Flaviviridae, genus Flavivirus, SLEV). We predicted differences in disease resistance among the blackbird species based on differences in life history, because they differ in geographic range and life history traits that include mating and breeding systems. Differences were observed among the response of these hosts to all three viruses, Red-winged Blackbirds were more susceptible to SLEV than Brewer's Blackbirds, whereas Brewer's Blackbirds were more susceptible to WEEV than Red-winged Blackbirds. In response to WNV infection, cowbirds showed the lowest mean viremias, cleared their infections faster, and showed lower antibody levels than concurrently infected species. Brown-headed Cowbirds also exhibited significantly lower viremia responses after infection with SLEV and WEEV as well as coinfection with WEEV and WNV than concurrently infected icterids. We concluded that cowbirds may be more resistant to infection to both native and introduced viruses because they experience heightened exposure to a variety of pathogens of parenting birds during the course of their parasitic life style.

  18. Altered Protein Networks and Cellular Pathways in Severe West Nile Disease in Mice

    NARCIS (Netherlands)

    C. Fraisier (Christophe); L. Camoin (Luc); S.M. Lim (Stephanie); M. Bakli (Mahfoud); M. Belghazi (Maya); P. Fourquet (Patrick); S. Granjeaud (Samuel); A.D.M.E. Osterhaus (Albert); P. Koraka (Penelope); B.E.E. Martina (Byron); L. Almeras (Lionel)

    2013-01-01

    textabstractBackground:The recent West Nile virus (WNV) outbreaks in developed countries, including Europe and the United States, have been associated with significantly higher neuropathology incidence and mortality rate than previously documented. The changing epidemiology, the constant risk of

  19. Infodemiological data of West-Nile virus disease in Italy in the study period 2004–2015

    Directory of Open Access Journals (Sweden)

    Nicola Luigi Bragazzi

    2016-12-01

    Full Text Available Google Trends (GT was mined from 2004 to 2015, searching for West-Nile virus disease (WNVD in Italy. GT-generated data were modeled as a time series and were analyzed using classical time series analyses. In particular, correlation between GT-based Relative Search Volumes (RSVs related to WNVD and “real-world” epidemiological cases in the same study period resulted r=0.76 (p<0.0001 on a monthly basis and r=0.80 (p<0.0001 on a yearly basis. The partial autocorrelation analysis and the spectral analysis confirmed that a 1-year regular pattern could be detected. Correlation between GT-based RSVs related to WNVD yielded a r=0.54 (p<0.05 on a regional basis. Summarizing, GT-generated data concerning WNVD well correlated with epidemiology and could be exploited for complementing traditional surveillance.

  20. West Nile Virus Infection in American Singer Canaries: An Experimental Model in a Highly Susceptible Avian Species.

    Science.gov (United States)

    Hofmeister, Erik K; Lund, Melissa; Shearn Bochsler, Valerie

    2018-01-01

    This study investigated the susceptibility of American singer canaries ( Serinus canaria) to West Nile virus (WNV) infection. Adult canaries were inoculated with 10 5 , 10 2 , and 10 1 plaque forming units (PFU) of WNV. All birds became infected and mortality occurred by 5 days postinoculation. The load of viral RNA as determined by RT-qPCR was dose dependent, and was higher at all doses than the level of viral RNA detected in American crows ( Corvus brachyrhynchos) challenged with 10 5 PFU of WNV. In a subset of birds, viremia was detected by virus isolation; canaries inoculated with 10 1 PFU of WNV developed viremia exceeding 10 10 PFU/mL serum, a log higher than American crows inoculated with 10 5 PFU of virus. In canaries euthanized at 3 days postinoculation, WNV was isolated at >10 7 PFU of virus/100 mg of lung, liver, heart, spleen, and kidney tissues. Pallor of the liver and splenomegaly were the most common macroscopic observations and histologic lesions were most severe in liver, spleen, and kidney, particularly in canaries challenged with 10 2 and 10 1 PFU. Immunoreactivity to WNV was pronounced in the liver and spleen. IgG antibodies to WNV were detected in serum by enzyme immunoassay in 11 of 21 (52%) challenged canaries and, in 4 of 5 (20%) of these sera, neutralization antibodies were detected at a titer ≥ 1:20. American singer canaries provide a useful model as this bird species is highly susceptible to WNV infection.

  1. West Nile virus infection in American singer canaries: An experimental model in a highly susceptible avian species

    Science.gov (United States)

    Hofmeister, Erik K.; Lund, Melissa; Shearn-Bochsler, Valerie I.

    2018-01-01

    This study investigated the susceptibility of American singer canaries (Serinus canaria) to West Nile virus (WNV) infection. Adult canaries were inoculated with 105, 102, and 101plaque forming units (PFU) of WNV. All birds became infected and mortality occurred by 5 days postinoculation. The load of viral RNA as determined by RT-qPCR was dose dependent, and was higher at all doses than the level of viral RNA detected in American crows (Corvus brachyrhynchos) challenged with 105 PFU of WNV. In a subset of birds, viremia was detected by virus isolation; canaries inoculated with 101 PFU of WNV developed viremia exceeding 1010 PFU/mL serum, a log higher than American crows inoculated with 105 PFU of virus. In canaries euthanized at 3 days postinoculation, WNV was isolated at >107 PFU of virus/100 mg of lung, liver, heart, spleen, and kidney tissues. Pallor of the liver and splenomegaly were the most common macroscopic observations and histologic lesions were most severe in liver, spleen, and kidney, particularly in canaries challenged with 102 and 101 PFU. Immunoreactivity to WNV was pronounced in the liver and spleen. IgG antibodies to WNV were detected in serum by enzyme immunoassay in 11 of 21 (52%) challenged canaries and, in 4 of 5 (20%) of these sera, neutralization antibodies were detected at a titer ≥ 1:20. American singer canaries provide a useful model as this bird species is highly susceptible to WNV infection.

  2. Global emergence of Zika virus

    Directory of Open Access Journals (Sweden)

    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.

  3. Syndromic surveillance for West Nile virus using raptors in rehabilitation.

    Science.gov (United States)

    Ana, Alba; Perez Andrés, M; Julia, Ponder; Pedro, Puig; Arno, Wünschmann; Kimberly, Vander Waal; Julio, Alvarez; Michelle, Willette

    2017-11-29

    Wildlife rehabilitation centers routinely gather health-related data from diverse species. Their capability to signal the occurrence of emerging pathogens and improve traditional surveillance remains largely unexplored. This paper assessed the utility for syndromic surveillance of raptors admitted to The Raptor Center (TRC) to signal circulation of West Nile Virus (WNV) in Minnesota between 1990 and 2014. An exhaustive descriptive analysis using grouping time series structures and models of interrupted times series was conducted for indicator subsets. A total of 13,080 raptors were monitored. The most representative species were red-tailed hawks, great horned owls, Cooper's hawks, American kestrels and bald eagles. Results indicated that temporal patterns of accessions at the TRC changed distinctively after the incursion of WNV in 2002. The frequency of hawks showing WNV-like signs increased almost 3 times during July and August, suggesting that monitoring of hawks admitted to TRC with WNV-like signs could serve as an indicator of WNV circulation. These findings were also supported by the results of laboratory diagnosis. This study demonstrates that monitoring of data routinely collected by wildlife rehabilitation centers has the potential to signal the spread of pathogens that may affect wild, domestic animals and humans, thus supporting the early detection of disease incursions in a region and monitoring of disease trends. Ultimately, data collected in rehabilitation centers may provide insights to efficiently allocate financial and human resources on disease prevention and surveillance.

  4. Dengue seroprevalence, seroconversion and risk factors in Dhaka, Bangladesh

    Science.gov (United States)

    Dhar-Chowdhury, Parnali; Paul, Kishor Kumar; Hossain, Shakhawat; Lindsay, L. Robbin; Dibernardo, Antonia; Brooks, W. Abdullah; Drebot, Michael A.

    2017-01-01

    Background Dengue virus (DENV) activity has been reported in Dhaka, Bangladesh since the early 1960s with the greatest burden of dengue fever and dengue hemorrhagic fever cases observed in 2000. Since this time, the intensity of dengue activity has varied from year to year, and its determining factors remained relatively unknown. In light of such gaps in knowledge, the main objectives of this study were to determine the magnitude of seroprevalence and seroconversion among the surveyed population, and establish the individual/household level risk factors for the presence of DENV antibodies among all age groups of target populations in the city of Dhaka. Methodology/Principal findings Considering the lack of fine scale investigations on the factors driving dengue activity in Bangladesh, a prospective cohort study involving serological surveys was undertaken with participant interviews and blood donation across the city of Dhaka in 2012. Study participants were recruited from 12 of 90 wards and blood samples were collected during both the pre-monsoon (n = 1125) and post-monsoon (n = 600) seasons of 2012. The findings revealed that the seroprevalence in all pre-monsoon samples was 80.0% (900/1125) while the seropositivity in the pre-monsoon samples that had paired post-monsoon samples was 83.3% (503/600). Of the 97 paired samples that were negative at the pre-monsoon time point, 56 were positive at the post-monsoon time point. This resulted in a seroprevalence of 93.2% (559/600) among individuals tested during the post-monsoon period. Seroprevalence trended higher with age with children exhibiting a lower seropositivity as compared to adults. Results from this study also indicated that DENV strains were the only flaviviruses circulating in Dhaka in 2012. A multivariate analysis revealed that age, possession of indoor potted plants, and types of mosquito control measures were significant factors associated with DENV seroprevalence; while attendance in public

  5. Diagnostic sensitivity and specificity of in situ hybridization and immunohistochemistry for Eastern equine encephalitis virus and West Nile virus in formalin-fixed, paraffin-embedded brain tissue of horses.

    Science.gov (United States)

    Pennick, Kate E; McKnight, Christy A; Patterson, Jon S; Latimer, Kenneth S; Maes, Roger K; Wise, Annabel G; Kiupel, Matti

    2012-03-01

    Immunohistochemistry (IHC) and in situ hybridization (ISH) can be used either to detect or to differentiate between Eastern equine encephalitis virus (EEEV) and West Nile virus (WNV) within formalin-fixed, paraffin-embedded (FFPE) brain tissue of horses. To compare the diagnostic sensitivity and specificity of ISH and IHC, FFPE brain tissue from 20 EEEV-positive horses and 16 WNV-positive horses were tested with both EEEV and WNV oligoprobes and EEEV- and WNV-specific antibodies. Reverse transcription polymerase chain reaction (RT-PCR) for detection of EEEV and WNV was used as the gold standard to confirm infection. All horses that tested positive for EEEV by RT-PCR also tested positive by IHC and ISH, except for 1 case that was false-negative by ISH. In contrast, all horses that tested positive for WNV by RT-PCR tested negative by IHC and only 2 horses tested positive by ISH. No false-positives were detected with either method for both viruses. Both IHC and ISH are highly specific and sensitive diagnostic methods to detect EEEV in equine FFPE brain tissues, although neither appear effective for the diagnosis of WNV in equine neurologic cases.

  6. Visual detection of West Nile virus using reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip

    Directory of Open Access Journals (Sweden)

    Zengguo eCao

    2016-04-01

    Full Text Available West Nile virus (WNV causes a severe zoonosis, which can lead to a large number of casualties and considerable economic losses. A rapid and accurate identification methodfor WNV for use in field laboratories is urgently needed. Here, a method utilizing reverse transcription loop-mediated isothermal amplification combined with a vertical flow visualization strip (RT-LAMP-VF was developed to detect the envelope (E gene of WNV. The RT-LAMP-VF assay could detect 102 copies/μl ofan WNV RNA standard using a 40 min amplification reaction followed by a 2 min incubationof the amplification product on the visualization strip, and no cross-reaction with other closely related members of theFlavivirus genus was observed. The assay was further evaluated using cells and mouse brain tissues infected with a recombinant rabies virus expressing the E protein of WNV.The assay produced sensitivities of 101.5TCID50/ml and 101.33 TCID50/ml for detection of the recombinant virus in the cells and brain tissues, respectively. Overall, the RT-LAMP-VF assay developed in this study is rapid, simple and effective, and it is therefore suitable for clinical application in the field.

  7. Seroprevalence of poliovirus antibodies in the Kansas City metropolitan area, 2012–2013

    Science.gov (United States)

    Wallace, Gregory S.; Pahud, Barbara A.; Weldon, William C.; Curns, Aaron T.; Oberste, M. Steven; Harrison, Christopher J.

    2017-01-01

    ABSTRACT No indigenous cases of poliomyelitis have occurred in the US since 1979; however the risk of importation persists until global eradication is achieved. The seropositivity rate for different age cohorts with exposures to different poliovirus vaccine types and wild virus in the US are not presently known. A convenience sample was conducted in the Kansas City metropolitan area during 2012–2103 with approximately 100 participants enrolled for each of 5 age cohorts categorized based on vaccine policy changes over time in the US. Immunization records for poliovirus vaccination were required for participants poliovirus serotypes. Seroprevalence was evaluated by demographics as well as between polio serotypes. The overall seroprevalence to poliovirus was 90.7%, 94.4%, and 83.3%, for types 1, 2, and 3, respectively. Seroprevalence was high (88.6%–96.2%) for all 3 types of poliovirus for the 6–10 y old age group that was likely to have received a complete schedule of IPV-only vaccination. Children 2–3 y of age, who have not yet completed their full IPV series, had lower seroprevalence compared with all older age groups for types 1 and 2 (p-value poliovirus in the population surveyed. Seroprevalence for subjects aged 2–3 y was lower than all other age groups for serotypes 1 and 2 highlighting the importance of completing the recommended poliovirus vaccine series with a booster dose at age 4–6 y. PMID:28059613

  8. Role of bird movements in the epidemiology of West Nile and avian influenza virus

    Science.gov (United States)

    Muzaffar, Sabir Bin; Hill, Nichola J.; Takekawa, John Y.; Perry, William M.; Smith, Lacy M.; Boyce, Walter M.

    2012-01-01

    Avian infl uenza virus (AIV) is infl uenced by site fi delity and movements of bird hosts. We examined the movement ecology of American crows (Corvus brachyrhynchos) as potential hosts for West Nile virus (WNV) and greater white-fronted geese (Anser albifrons frontalis) as potential hosts for AIVs. Research was based on radio-telemetry studies conducted in the Central Valley of California, USA. While crows were restricted to a small area of only a few square kilometers, the distribution of the geese encompassed the northern Central Valley. The crows used 1.5 to 3.5 different roosting areas monthly from February through October, revealing lower roost fi delity than the geese that used 1.1 to 1.5 roosting areas each month from November through March. The crows moved a mean distance of 0.11 to 0.49 km/month between their roosting sites and 2.5 to 3.9 km/month between roosting and feeding sites. In contrast, the geese moved 4.2 to 19.3 km/month between roosting areas, and their feeding range varied from 13.2 to 19.0 km/month. Our comparison of the ecological characteristics of bird movements suggests that the limited local movements of crows coupled with frequent turnover of roosts may result in persistence of focal areas for WNV infection. In contrast, widespread areas used by geese will provide regular opportunities for intermixing of AIVs over a much greater geographic area.

  9. Culex pipiens and Stegomyia albopicta (= Aedes albopictus) populations as vectors for lineage 1 and 2 West Nile virus in Europe.

    Science.gov (United States)

    Brustolin, M; Talavera, S; Santamaría, C; Rivas, R; Pujol, N; Aranda, C; Marquès, E; Valle, M; Verdún, M; Pagès, N; Busquets, N

    2016-06-01

    The emerging disease West Nile fever is caused by West Nile virus (WNV), one of the most widespread arboviruses. This study represents the first test of the vectorial competence of European Culex pipiens Linnaeus 1758 and Stegomyia albopicta (= Aedes albopictus) (both: Diptera: Culicidae) populations for lineage 1 and 2 WNV isolated in Europe. Culex pipiens and S. albopicta populations were susceptible to WNV infection, had disseminated infection, and were capable of transmitting both WNV lineages. This is the first WNV competence assay to maintain mosquito specimens under environmental conditions mimicking the field (day/night) conditions associated with the period of maximum expected WNV activity. The importance of environmental conditions is discussed and the issue of how previous experiments conducted in fixed high temperatures may have overestimated WNV vector competence results with respect to natural environmental conditions is analysed. The information presented should be useful to policymakers and public health authorities for establishing effective WNV surveillance and vector control programmes. This would improve preparedness to prevent future outbreaks. © 2016 The Authors. Medical and Veterinary Entomology published by John Wiley & Sons Ltd on behalf of Royal Entomological Society.

  10. Increased Hepatitis E Virus Seroprevalence Correlates with Lower CD4+ Cell Counts in HIV-Infected Persons in Argentina.

    Directory of Open Access Journals (Sweden)

    José D Debes

    Full Text Available Hepatitis E virus (HEV is a single-stranded RNA virus that can cause hepatitis in an epidemic fashion. HEV usually causes asymptomatic or limited acute infections in immunocompetent individuals, whereas in immunosuppressed individuals such as transplant recipients, HEV can cause chronic infections. The risks and outcomes of HEV co-infection in patients infected with human immunodeficiency virus (HIV are poorly characterized. We used a third generation immunoassay to measure serum IgG antibodies specific for HEV in 204 HIV-infected individuals from Argentina and a control group of 433 HIV-negative individuals. We found 15 of 204 (7.3%, 95%CI 3.74-10.96% individuals in the HIV-positive group to have positive HEV IgG levels suggestive of previous infection, compared to 19 of 433 (4.4%, 95% CI 2.5-6.3% individuals in the HIV-negative control group (p = 0.12. Among HIV-positive individuals, those with HEV seropositivity had lower CD4 counts compared to those that were HEV seronegative (average CD4 count of 234 vs 422 mm3, p = 0.01, indicating that patients with lower CD4 counts were more likely to be HEV IgG positive. Moreover, HEV seropositivity in patients with CD4 counts 200 mm3 (p = 0.012. We found a positive PCR result for HEV in one individual. Our study found that increased seroprevalence of HEV IgG correlated with lower CD4 counts in HIV-infected patients in Argentina.

  11. First Report of Hepatitis E Virus Infection in Sika Deer in China

    Directory of Open Access Journals (Sweden)

    Xiao-Xuan Zhang

    2015-01-01

    Full Text Available Hepatitis E virus (HEV, a single stranded RNA, nonenveloped virus, belongs to the genus Hepevirus, in the family of Hepeviridae. In this study, 46 (5.43% out of the 847 serum samples from sika deer (Cervus nippon were detected as seropositive with hepatitis E virus (HEV by enzyme linked immunosorbent assay (ELISA. These samples were collected from Inner Mongolia and Jilin and Heilongjiang provinces in China, between October 2012 and October 2013. Seroprevalence of HEV infection in male and female deer was 4.82% and 6.52%, respectively. HEV seroprevalence in sika deer from different geographical locations varied from 3.13% to 6.73%. There was no significant difference in HEV seroprevalence between sika deer collected in autumn (5.65% and winter (4.85%. This is the first report of HEV seroprevalence in sika deer in China, which will provide foundation information for estimating the effectiveness of future measures to control HEV infection in sika deer in China and assessing the potential risk of humans infected with HEV after consumption of undercooked or raw meat from infected sika deer.

  12. First report of hepatitis E virus infection in sika deer in China.

    Science.gov (United States)

    Zhang, Xiao-Xuan; Qin, Si-Yuan; Zhang, Yuan; Meng, Qing-Feng; Jiang, Jing; Yang, Gui-Lian; Zhao, Quan; Zhu, Xing-Quan

    2015-01-01

    Hepatitis E virus (HEV), a single stranded RNA, nonenveloped virus, belongs to the genus Hepevirus, in the family of Hepeviridae. In this study, 46 (5.43%) out of the 847 serum samples from sika deer (Cervus nippon) were detected as seropositive with hepatitis E virus (HEV) by enzyme linked immunosorbent assay (ELISA). These samples were collected from Inner Mongolia and Jilin and Heilongjiang provinces in China, between October 2012 and October 2013. Seroprevalence of HEV infection in male and female deer was 4.82% and 6.52%, respectively. HEV seroprevalence in sika deer from different geographical locations varied from 3.13% to 6.73%. There was no significant difference in HEV seroprevalence between sika deer collected in autumn (5.65%) and winter (4.85%). This is the first report of HEV seroprevalence in sika deer in China, which will provide foundation information for estimating the effectiveness of future measures to control HEV infection in sika deer in China and assessing the potential risk of humans infected with HEV after consumption of undercooked or raw meat from infected sika deer.

  13. Seroprevalence of Japanese encephalitis virus using competitive enzyme linked immunosorbent assay (C-ELISA in pigs in East Sumba, Indonesia

    Directory of Open Access Journals (Sweden)

    Annytha Detha

    2015-12-01

    Full Text Available Japanese Encephalitis (JE, a vector-borne zoonotic viral disease, is mostly prevalent in Asian countries. The objective of this study was to investigate the occurence of JE virus (JEV among pigs in East Sumba, Indonesia. Blood samples (n=52 were randomly collected from 52 apparantly healthy pigs where pig population was high in East Sumba. The samples were subjected for seroprevalence study for the presence of antibodies against JEV using competitive enzyme linked immunosorbent assay (C-ELISA. Results showed that 53% (n=28/52 blood samples from the pigs contained antibodies against JEV. This finding is suggestive that the JEV is circulating among pig population in East Sumba, Indonesia. The data may help in designing control strategies of the JEV in the East Sumba, Indonesia.

  14. Surveillance for West Nile Virus in Wild Birds from Northern Europe

    Czech Academy of Sciences Publication Activity Database

    Jourdain, E.; Olsen, B.; Lundkvist, A.; Hubálek, Zdeněk; Šikutová, Silvie; Waldenström, J.; Karlsson, M.; Wahlström, M.; Jozan, M.; Falk, K. I.

    2011-01-01

    Roč. 11, č. 1 (2011), s. 77-79 ISSN 1530-3667 Institutional research plan: CEZ:AV0Z60930519 Keywords : Antibodies * Migratory birds * Sweden * West Nile Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology Impact factor: 2.437, year: 2011

  15. Hepatitis B virus, syphilis, and HIV seroprevalence in pregnant women and their male partners from six indigenous populations of the Peruvian Amazon Basin, 2007-2008.

    Science.gov (United States)

    Ormaeche, Melvy; Whittembury, Alvaro; Pun, Mónica; Suárez-Ognio, Luis

    2012-10-01

    To assess the seroprevalence of hepatitis B virus (HBV), syphilis, and HIV and associated risk factors in pregnant women and their male partners from six indigenous populations of the Peruvian Amazon Basin. A cross-sectional study was performed in six indigenous populations from the Peruvian Amazon Basin. Blood samples were obtained and tested for HBV (antibodies to the hepatitis B core antigen (anti-HBc) and hepatitis B surface antigen (HBsAg)), for syphilis (rapid plasma reagin and microhemagglutination assay for Treponema pallidum antibodies), and for HIV (ELISA and indirect immunofluorescence test). A survey was also performed to identify associated risk factors. One thousand two hundred and fifty-one pregnant women and 778 male partners were enrolled in the study. The seroprevalence of anti-HBc in pregnant women was 42.06% (95% confidence interval (CI) 39.28-44.85%) and in their male partners was 54.09% (95% CI 50.32-57.86%). The seroprevalence of HBsAg in pregnant women was 2.11% (95% CI 0.78-3.44%) and in their male partners was 3.98% (95% CI 1.87-6.08%). The seroprevalence of syphilis in pregnant women was 1.60% (95% CI 0.86-2.33%) and in their male partners was 2.44% (95% CI 1.22-3.66%). HIV seroprevalence in pregnant women was 0.16% (95% CI 0.02-0.58%) and in their male partners was 0.29% (95% CI 0.04-1.03%). Sexual risk factors were strongly related to blood markers of syphilis and HBV. Hepatitis B was found to be hyperendemic and strongly related to sexual factors, suggesting an important sexual component in the transmission of the disease in the populations studied. Syphilis was found to have an endemicity in pregnant women above the national level and this may be indicative of high mother-to-child transmission. HIV has started to show its presence in indigenous populations of the Amazon Basin and the results suggest the epidemic is concentrated. Copyright © 2012 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights

  16. Seroprevalence of H1N1, H3N2 and H1N2 influenza viruses in pigs in seven European countries in 2002-2003.

    Science.gov (United States)

    Van Reeth, Kristien; Brown, Ian H; Dürrwald, Ralf; Foni, Emanuela; Labarque, Geoffrey; Lenihan, Patrick; Maldonado, Jaime; Markowska-Daniel, Iwona; Pensaert, Maurice; Pospisil, Zdenek; Koch, Guus

    2008-05-01

    Avian-like H1N1 and human-like H3N2 swine influenza viruses (SIV) have been considered widespread among pigs in Western Europe since the 1980s, and a novel H1N2 reassortant with a human-like H1 emerged in the mid 1990s. This study, which was part of the EC-funded 'European Surveillance Network for Influenza in Pigs 1', aimed to determine the seroprevalence of the H1N2 virus in different European regions and to compare the relative prevalences of each SIV between regions. Laboratories from Belgium, the Czech Republic, Germany, Italy, Ireland, Poland and Spain participated in an international serosurvey. A total of 4190 sow sera from 651 farms were collected in 2002-2003 and examined in haemagglutination inhibition tests against H1N1, H3N2 and H1N2. In Belgium, Germany, Italy and Spain seroprevalence rates to each of the three SIV subtypes were high (> or =30% of the sows seropositive) to very high (> or =50%), except for a lower H1N2 seroprevalence rate in Italy (13.8%). Most sows in these countries with high pig populations had antibodies to two or three subtypes. In Ireland, the Czech Republic and Poland, where swine farming is less intensive, H1N1 was the dominant subtype (8.0-11.7% seropositives) and H1N2 and H3N2 antibodies were rare (0-4.2% seropositives). Thus, SIV of H1N1, H3N2 and H1N2 subtype are enzootic in swine producing regions of Western Europe. In Central Europe, SIV activity is low and the circulation of H3N2 and H1N2 remains to be confirmed. The evolution and epidemiology of SIV throughout Europe is being further monitored through a second 'European Surveillance Network for Influenza in Pigs'.

  17. Hepatitis E Virus Genotype 3 in Humans and Swine, Bolivia

    Science.gov (United States)

    Cavallo, Annalisa; Gonzales, José Luis; Bonelli, Sara Irene; Valda, Ybar; Pieri, Angela; Segundo, Higinio; Ibañez, Ramón; Mantella, Antonia; Bartalesi, Filippo; Tolari, Francesco; Bartoloni, Alessandro

    2011-01-01

    We determined the seroprevalence of hepatitis E virus (HEV) in persons in 2 rural communities in southeastern Bolivia and the presence of HEV in human and swine fecal samples. HEV seroprevalence was 6.3%, and HEV genotype 3 strains with high sequence homology were detected. PMID:21801630

  18. Importance of Wetlands Management for West Nile Virus Circulation Risk, Camargue, Southern France

    Directory of Open Access Journals (Sweden)

    Sophie Pradier

    2014-08-01

    Full Text Available To assess environmental and horse-level risk factors associated with West Nile Virus (WNV circulation in Camargue, Southern France, a serosurvey was conducted on non-vaccinated horses (n = 1159 from 134 stables in 2007 and 2008. Fifteen Landsat images were examined to quantify areas with open water and flooded vegetation around sampled horses. Mean percentages of areas of open water and flooded vegetation, as well as variations in these percentages between 3 periods (November to February = NOT, March to July = END and August to October = EPI, were calculated for buffers of 2 km radius around the stables. Results of the final logistic regression showed that the risk of WNV seropositivity in horses decreased with their date of acquisition and age. Results also demonstrated the significant role of environmental variables. Horse serological status was associated with variations of open water areas between the NOT (November to February and END (March to July periods, as well as between END and EPI (August to October. WNV spillover was found more intense in areas where water level decreased strongly from winter to spring and from spring to summer.

  19. West Nile virus infection in American Robins: new insights on dose response.

    Directory of Open Access Journals (Sweden)

    Kaci K VanDalen

    Full Text Available West Nile virus (WNV is a vector-borne pathogen that was first detected in the United States in 1999. The natural transmission cycle of WNV involves mosquito vectors and avian hosts, which vary in their competency to transmit the virus. American robins are an abundant backyard species in the United States and appear to have an important role in the amplification and dissemination of WNV. In this study we examine the response of American robins to infection with various WNV doses within the range of those administered by some natural mosquito vectors. Thirty American robins were assigned a WNV dosage treatment and needle inoculated with 10(0.95 PFU, 10(1.26 PFU, 10(2.15 PFU, or 10(3.15 PFU. Serum samples were tested for the presence of infectious WNV and/or antibodies, while oral swabs were tested for the presence of WNV RNA. Five of the 30 (17% robins had neutralizing antibodies to WNV prior to the experiment and none developed viremia or shed WNV RNA. The proportion of WNV-seronegative birds that became viremic after WNV inoculation increased in a dose dependent manner. At the lowest dose, only 40% (2/5 of the inoculated birds developed productive infections while at the highest dose, 100% (7/7 of the birds became viremic. Oral shedding of WNV RNA followed a similar trend where robins inoculated with the lower two doses were less likely to shed viral RNA (25% than robins inoculated with one of the higher doses (92%. Viremia titers and morbidity did not increase in a dose dependent manner; only two birds succumbed to infection and, interestingly, both were inoculated with the lowest dose of WNV. It is clear that the disease ecology of WNV is a complex interplay of hosts, vectors, and viral dose delivered.

  20. Serological Evidence of Human Infection with Avian Influenza A H7virus in Egyptian Poultry Growers.

    Science.gov (United States)

    Gomaa, Mokhtar R; Kandeil, Ahmed; Kayed, Ahmed S; Elabd, Mona A; Zaki, Shaimaa A; Abu Zeid, Dina; El Rifay, Amira S; Mousa, Adel A; Farag, Mohamed M; McKenzie, Pamela P; Webby, Richard J; Ali, Mohamed A; Kayali, Ghazi

    2016-01-01

    Avian influenza viruses circulate widely in birds, with occasional human infections. Poultry-exposed individuals are considered to be at high risk of infection with avian influenza viruses due to frequent exposure to poultry. Some avian H7 viruses have occasionally been found to infect humans. Seroprevalence of neutralizing antibodies against influenza A/H7N7 virus among poultry-exposed and unexposed individuals in Egypt were assessed during a three-years prospective cohort study. The seroprevalence of antibodies (titer, ≥80) among exposed individuals was 0%, 1.9%, and 2.1% annually while the seroprevalence among the control group remained 0% as measured by virus microneutralization assay. We then confirmed our results using western blot and immunofluorescence assays. Although human infection with H7 in Egypt has not been reported yet, our results suggested that Egyptian poultry growers are exposed to avian H7 viruses. These findings highlight the need for surveillance in the people exposed to poultry to monitor the risk of zoonotic transmission of avian influenza viruses.

  1. Serological Evidence of Human Infection with Avian Influenza A H7virus in Egyptian Poultry Growers.

    Directory of Open Access Journals (Sweden)

    Mokhtar R Gomaa

    Full Text Available Avian influenza viruses circulate widely in birds, with occasional human infections. Poultry-exposed individuals are considered to be at high risk of infection with avian influenza viruses due to frequent exposure to poultry. Some avian H7 viruses have occasionally been found to infect humans. Seroprevalence of neutralizing antibodies against influenza A/H7N7 virus among poultry-exposed and unexposed individuals in Egypt were assessed during a three-years prospective cohort study. The seroprevalence of antibodies (titer, ≥80 among exposed individuals was 0%, 1.9%, and 2.1% annually while the seroprevalence among the control group remained 0% as measured by virus microneutralization assay. We then confirmed our results using western blot and immunofluorescence assays. Although human infection with H7 in Egypt has not been reported yet, our results suggested that Egyptian poultry growers are exposed to avian H7 viruses. These findings highlight the need for surveillance in the people exposed to poultry to monitor the risk of zoonotic transmission of avian influenza viruses.

  2. West Nile virus activity in Latin America and the Caribbean La actividad del virus del Nilo occidental en América Latina y el Caribe

    Directory of Open Access Journals (Sweden)

    Nicholas Komar

    2006-02-01

    Full Text Available OBJECTIVES: West Nile virus (Flavivirus: Flaviviridae; WNV has spread rapidly throughout the Caribbean Basin since its initial detection there in 2001. This report summarizes our current knowledge of WNV transmission in tropical America. METHODS: We reviewed the published literature and consulted with key public health officials to obtain unpublished data. RESULTS: West Nile virus infections first appeared in human residents of the Cayman Islands and the Florida Keys in 2001, and in apparently healthy Jamaican birds sampled early in 2002. Serologic evidence of WNV infection in 2002 was detected in horses, chickens and resident free-ranging birds in Guadeloupe, the Dominican Republic, and eastern Mexico. In 2003, WNV spread in Mexico and northern Central America, and serologic evidence was detected in the Bahamas, Puerto Rico and Cuba. In 2004, the first serologic evidence of WNV activity in South American ecosystems surfaced in September-October in Colombia and Trinidad, where domestic animals circulated WNV-neutralizing antibodies. CONCLUSIONS: The sparse reports of equine, human and avian disease in Latin America and the Caribbean is puzzling. Isolates are needed to evaluate viral attenuation or other possible explanations for reduced disease burden in tropical ecosystems.OBJETIVOS: El virus del Nilo occidental (VNO, familia Flaviviridae, género Flavivirus se ha propagado rápidamente por toda la cuenca del Caribe desde que se detectó por primera vez en 2001. En este informe se resumen nuestros conocimientos actuales acerca de la transmisión del VNO en zonas tropicales del continente americano. MÉTODOS: Revisamos todo lo que se ha publicado sobre el tema y consultamos a autoridades de salud clave para obtener datos inéditos. RESULTADOS: Las infecciones por el virus del Nilo occidental aparecieron por primera vez en seres humanos residentes de las Islas Caimán y de los Cayos de la Florida en 2001, y en pájaros de aspecto sano de los

  3. A mutation in the envelope protein fusion loop attenuates mouse neuroinvasiveness of the NY99 strain of West Nile virus

    International Nuclear Information System (INIS)

    Zhang Shuliu; Li Li; Woodson, Sara E.; Huang, Claire Y.-H.; Kinney, Richard M.; Barrett, Alan D.T.; Beasley, David W.C.

    2006-01-01

    Substitutions were engineered individually and in combinations at the fusion loop, receptor-binding domain and a stem-helix structure of the envelope protein of a West Nile virus strain, NY99, and their effects on mouse virulence and presentation of epitopes recognized by monoclonal antibodies (MAbs) were assessed. A single substitution within the fusion loop (L107F) attenuated mouse neuroinvasiveness of NY99. No substitutions attenuated NY99 neurovirulence. The L107F mutation also abolished binding of a non-neutralizing MAb, 3D9, whose epitope had not been previously identified. MAb 3D9 was subsequently shown to be broadly cross-reactive with other flaviviruses, consistent with binding near the highly conserved fusion loop

  4. Spatial Analysis of West Nile Virus: Predictive Risk Modeling of a Vector-borne Infectious Disease in Illinois by Means of NASA Earth Observation Systems

    Science.gov (United States)

    Renneboog, Nathan; Gathings, David; Hemmings, Sarah; Makasa, Emmanuel; Omer, Wigdan; Tipre, Meghan; Wright, Catherine; McAllister, Marilyn; Luvall, Jeffrey C.

    2009-01-01

    West Nile Virus is a mosquito-borne virus of the family Flaviviridae. It infects birds and various mammals, including humans, and can cause encephalitis that may prove fatal, notably among vulnerable populations. Since its identification in New York City in 1999, WNV has become established in a broad range of ecological settings throughout North America, infecting more than 25,300 people and killing 1133 as of 2008 (CDC,2009). WNV is transmitted by mosquitoes that feed on infected birds. As a result, the degree of human infection depends on local ecology and human exposure. This study hypothesizes that remote sensing and GIS can be used to analyze environmental determinants of WNV transmission, such as climate, elevation, land cover, and vegetation densities, to map areas of WNV risk for surveillance and intervention.

  5. Proximity of Residence to Bodies of Water and Risk for West Nile Virus Infection: A Case-Control Study in Houston, Texas

    Directory of Open Access Journals (Sweden)

    Melissa S. Nolan

    2012-01-01

    Full Text Available West Nile virus (WNV, a mosquito-borne virus, has clinically affected hundreds of residents in the Houston metropolitan area since its introduction in 2002. This study aimed to determine if living within close proximity to a water source increases one’s odds of infection with WNV. We identified 356 eligible WNV-positive cases and 356 controls using a population proportionate to size model with US Census Bureau data. We found that living near slow moving water sources was statistically associated with increased odds for human infection, while living near moderate moving water systems was associated with decreased odds for human infection. Living near bayous lined with vegetation as opposed to concrete also showed increased risk of infection. The habitats of slow moving and vegetation lined water sources appear to favor the mosquito-human transmission cycle. These methods can be used by resource-limited health entities to identify high-risk areas for arboviral disease surveillance and efficient mosquito management initiatives.

  6. West nile virus prevalence across landscapes is mediated by local effects of agriculture on vector and host communities.

    Science.gov (United States)

    Crowder, David W; Dykstra, Elizabeth A; Brauner, Jo Marie; Duffy, Anne; Reed, Caitlin; Martin, Emily; Peterson, Wade; Carrière, Yves; Dutilleul, Pierre; Owen, Jeb P

    2013-01-01

    Arthropod-borne viruses (arboviruses) threaten the health of humans, livestock, and wildlife. West Nile virus (WNV), the world's most widespread arbovirus, invaded the United States in 1999 and rapidly spread across the county. Although the ecology of vectors and hosts are key determinants of WNV prevalence across landscapes, the factors shaping local vector and host populations remain unclear. Here, we used spatially-explicit models to evaluate how three land-use types (orchards, vegetable/forage crops, natural) and two climatic variables (temperature, precipitation) influence the prevalence of WNV infections and vector/host distributions at landscape and local spatial scales. Across landscapes, we show that orchard habitats were associated with greater prevalence of WNV infections in reservoirs (birds) and incidental hosts (horses), while increased precipitation was associated with fewer infections. At local scales, orchard habitats increased the prevalence of WNV infections in vectors (mosquitoes) and the abundance of mosquitoes and two key reservoir species, the American robin and the house sparrow. Thus, orchard habitats benefitted WNV vectors and reservoir hosts locally, creating focal points for the transmission of WNV at landscape scales in the presence of suitable climatic conditions.

  7. West Nile virus in livestock and wildlife

    Science.gov (United States)

    McLean, R.G.; Ubico, S.R.; Bourne, D.; Komar, N.

    2002-01-01

    WN virus is one of the most ubiquitous arboviruses occurring over a broad geographical range and in a wide diversity of vertebrate host and vector species. The virus appears to be maintained in endemic foci on the African continent and is transported annually to temperate climates to the north in Europe and to the south in South Africa. Reports of clinical disease due to natural WN virus infection in wild or domestic animals were much less common than reports of infection (virus isolation or antibody detection). Until recently, records of morbidity and mortality in wild birds were confined to a small number of cases and infections causing encephalitis, sometimes fatal, in horses were reported infrequently. In the period 1996-2001, there was an increase in outbreaks of illness due to WN virus in animals as well as humans. Within the traditional range of WN virus, encephalitis was reported in horses in Italy in 1998 and in France in 2000. The first report of disease and deaths caused by WN virus infection in domestic birds was reported in Israel in 1997-1999, involving hundreds of young geese. In 1999 WN virus reached North America and caused an outbreak of encephalitis in humans in the New York area at the same time as a number of cases of equine encephalitis and deaths in American crows and a variety of other bird species, both North American natives and exotics. Multi-state surveillance for WN virus has been in place since April 2000 and has resulted in the detection of WN virus in thousands of dead birds from an increasing number of species in North America, and also in several species of mammals. The surveillance system that has developed in North America because of the utility of testing dead birds for the rapid detection of WN virus presence has been a unique integration of public health and wildlife health agencies. It has been suggested that the recent upsurge in clinical WN virus infection in wild and domestic animals as well as in humans may be related to

  8. Diverse host feeding on nesting birds may limit early-season West Nile virus amplification.

    Science.gov (United States)

    Egizi, Andrea M; Farajollahi, Ary; Fonseca, Dina M

    2014-06-01

    Arboviral activity tracks vector availability, which in temperate regions means that transmission ceases during the winter and must be restarted each spring. In the northeastern United States, Culex restuans Theobald resumes its activity earlier than Culex pipiens L. and is thought to be important in restarting West Nile virus (WNV) transmission. Its role in WNV amplification, however, is unclear, because viral levels commonly remain low until the rise of Cx. pipiens later in the season. Because a vector's feeding habits can reveal key information about disease transmission, we identified early-season (April-June) blood meals from Cx. restuans collected throughout New Jersey, and compared them to published datasets from later in the season and also from other parts of the country. We found significantly higher avian diversity, including poor WNV hosts, and fewer blood meals derived from American Robins (17% versus over 40% found in later season). Critically, we identified blood meals from significantly more female than male birds in species where females are the incubating sex, suggesting that Cx. restuans is able to feed on such a wide variety of hosts in early spring because incubating birds are easy targets. Because WNV amplification depends on virus consistently reaching competent hosts, our results indicate that Cx. restuans is unlikely to be an amplifying vector of WNV in the early season. As the season progresses, however, changes in the availability of nesting birds may make it just as capable as Cx. pipiens, although at somewhat lower abundance as the summer progresses.

  9. Comprehensive mapping of common immunodominant epitopes in the West Nile virus nonstructural protein 1 recognized by avian antibody responses.

    Directory of Open Access Journals (Sweden)

    Encheng Sun

    Full Text Available West Nile virus (WNV is a mosquito-borne flavivirus that primarily infects birds but occasionally infects humans and horses. Certain species of birds, including crows, house sparrows, geese, blue jays and ravens, are considered highly susceptible hosts to WNV. The nonstructural protein 1 (NS1 of WNV can elicit protective immune responses, including NS1-reactive antibodies, during infection of animals. The antigenicity of NS1 suggests that NS1-reactive antibodies could provide a basis for serological diagnostic reagents. To further define serological reagents for diagnostic use, the antigenic sites in NS1 that are targeted by host immune responses need to be identified and the potential diagnostic value of individual antigenic sites also needs to be defined. The present study describes comprehensive mapping of common immunodominant linear B-cell epitopes in the WNV NS1 using avian WNV NS1 antisera. We screened antisera from chickens, ducks and geese immunized with purified NS1 for reactivity against 35 partially overlapping peptides covering the entire WNV NS1. This study identified twelve, nine and six peptide epitopes recognized by chicken, duck and goose antibody responses, respectively. Three epitopes (NS1-3, 14 and 24 were recognized by antibodies elicited by immunization in all three avian species tested. We also found that NS1-3 and 24 were WNV-specific epitopes, whereas the NS1-14 epitope was conserved among the Japanese encephalitis virus (JEV serocomplex viruses based on the reactivity of avian WNV NS1 antisera against polypeptides derived from the NS1 sequences of viruses of the JEV serocomplex. Further analysis showed that the three common polypeptide epitopes were not recognized by antibodies in Avian Influenza Virus (AIV, Newcastle Disease Virus (NDV, Duck Plague Virus (DPV and Goose Parvovirus (GPV antisera. The knowledge and reagents generated in this study have potential applications in differential diagnostic approaches and

  10. Oral and parenteral immunization of chickens (Gallus gallus) against West Nile virus with recombinant envelope protein

    Science.gov (United States)

    Fassbinder-Orth, C. A.; Hofmeister, Erik K.; Weeks-Levy, C.; Karasov, W.H.

    2009-01-01

    West Nile virus (WNV) causes morbidity and mortality in humans, horses, and in more than 315 bird species in North America. Currently approved WNV vaccines are designed for parenteral administration and, as yet, no effective oral WNV vaccines have been developed. WNV envelope (E) protein is a highly antigenic protein that elicits the majority of virus-neutralizing antibodies during a WNV immune response. Leghorn chickens were given three vaccinations (each 2 wk apart) of E protein orally (20 ??g or 100 ??g/dose), of E protein intramuscularly (IM, 20 ??g/dose), or of adjuvant only (control group) followed by a WNV challenge. Viremias were measured post-WNV infection, and three new enzyme-linked immunosorbent assays were developed for quantifying IgM, IgY, and IgA-mediated immune response of birds following WNV infection. WNV viremia levels were significantly lower in the IM group than in both oral groups and the control group. Total WNV E protein-specific IgY production was significantly greater, and WNV nonstructural 1-specific IgY was significantly less, in the IM group compared to all other treatment groups. The results of this study indicate that IM vaccination of chickens with E protein is protective against WNV infection and results in a significantly different antibody production profile as compared to both orally vaccinated and nonvaccinated birds. ?? 2009 American Association of Avian Pathologists.

  11. Seroprevalence of varicella antibodies among pregnant women in Lyon-France

    International Nuclear Information System (INIS)

    Saadatian-Elahi, M.; Mekki, Y.; Signore, C. del; Lina, B.; Derrough, T.; Caulin, E.; Thierry, J.; Vanhems, P.

    2007-01-01

    The purpose of the study was to calculate the seroprevalence of immunity to the varicella-zoster virus (VZV) infection and to evaluate the positive predictive value (PPV) and the negative predictive value (NPV) of the self-reported history of VZV infection in pregnant women. A cross sectional study was conducted in 18 private medical analysis laboratories. Information on socio-demographic characteristics and past history of varicella or zoster were collected using a questionnaire. Blood samples were obtained to determine the serological levels of past exposure to VZV. Overall, 486 pregnant women were recruited. The seroprevalence of VZV antibodies was 98.8%. Six women were seronegative, of whom four were primiparous. The PPV was high (99.5%) while the NPV was only 10.3%. The PPV is a reliable marker of prior VZV infection. In contrast, a negative history does not predict lack of immunity and should be completed by serological analysis which might be introduced to routine antenatal blood tests

  12. Seroprevalence of hepatitis C in pregnant females of Hazara division

    International Nuclear Information System (INIS)

    Gul, N.; Idris, M.; Sarwar, J.; Suleman, M.

    2009-01-01

    Hepatitis C Virus (HCV), the causative agent of Hepatitis C is prevalent in different countries including Pakistan. Studies have been conducted on various aspects of HCV in Pakistan. The present study was planed to see the prevalence of hepatitis C in pregnant females of Hazara Division. Five hundred pregnant females of reproductive age group from Hazara Division selected by non probability convenient sampling technique were studied from 1, March 2006 to 28, February 2007 at Ayub Teaching Hospital, and District Head quarter Hospitals Abbottabad, Haripur and Mansehra. After initial serving by immunology technique positive cases were confirmed by Enzyme Linked Immunosorbent Essay (ELISA). Seroprevalence of HCV in pregnant females of Hazara division was 8.9%. Females aged from 25-35 constituted the largest group among positive cases. HCV was more prevalent in District Abbottabad as compared to the other districts of Hazara division. Seroprevalence of HCV in pregnant females of Hazara Division is different from the figures already reported form the other parts of Pakistan. (author)

  13. West Nile virus blood transfusion-related infection despite nucleic acid testing.

    Science.gov (United States)

    Macedo de Oliveira, Alexandre; Beecham, Brady D; Montgomery, Susan P; Lanciotti, Robert S; Linnen, Jeffrey M; Giachetti, Cristina; Pietrelli, Larry A; Stramer, Susan L; Safranek, Thomas J

    2004-12-01

    A case of West Nile virus (WNV) encephalitis associated with transfusion of blood that did not react when tested for WNV by minipool (MP) nucleic acid testing (NAT) is described. A Nebraska man developed clinical encephalitis 13 days after surgery and transfusion of 26 blood components. Antibody testing confirmed WNV infection. An investigation was initiated to determine the source of this infection. The patient's family members were interviewed to identify risk factors for WNV infection. Residual samples were retested for WNV RNA using transcription-mediated amplification (TMA) assay and two polymerase chain reaction (PCR) assays. Blood donors' follow-up serum samples were collected. All samples were tested for WNV-specific immunoglobulin M antibodies. The patient's family denied recent mosquito exposure. The 20 blood components collected after July 2003 did not react when tested for WNV in a six-member MP-NAT at the time of donation. Retrospective individual testing identified one sample as WNV-reactive by the TMA assay and one of the PCR assays. Seroconversion was demonstrated in the donor associated with this sample. WNV RNA detection by individual donation NAT demonstrates viremic blood escaping MP-NAT and supports transfusion-related WNV transmission. MP-NAT may not detect all WNV-infected blood donors, allowing WNV transmission to continue at low levels. WNV NAT assays might vary in sensitivity and pooling donations could further impact test performance. Understanding MP NAT limitations can improve strategies to maintain safety of the blood supply in the United States.

  14. Conserved amino acids within the N-terminus of the West Nile virus NS4A protein contribute to virus replication, protein stability and membrane proliferation

    International Nuclear Information System (INIS)

    Ambrose, R.L.; Mackenzie, J.M.

    2015-01-01

    The West Nile virus strain Kunjin virus (WNV KUN ) NS4A protein is a multifunctional protein involved in many aspects of the virus life-cycle and is a major component of the WNV KUN replication complex (RC). Previously we identified a conserved region in the C-terminus of NS4A regulating proteolytic processing and RC assembly, and now investigate key conserved residues in the N-terminus of NS4A and their contribution to WNV KUN replication. Mutation of P13 completely ablated replication, whereas, mutation of P48 and D49, near the first transmembrane helix, and G66 within the helix, showed variable defects in replication, virion secretion and membrane proliferation. Intriguingly, the P48 and G66 NS4A mutants resulted in specific proteasome depletion of NS4A that could in part be rescued with a proteasome inhibitor. Our results suggest that the N-terminus of NS4A contributes to correct folding and stability, essential for facilitating the essential roles of NS4A during replication. - Highlights: • Mutation of Proline13 of the WNV NS4A protein is lethal to replication. • 1st TMB helix of NS4A contributes to protein stability and membrane remodelling. • Unstable mutants of NS4A can be rescued with a proteasome inhibitor. • This study (and of others) contributes to a functional mapping of the NS4A protein

  15. High seroprevalence of human herpesviruses in HIV-infected individuals attending primary healthcare facilities in rural South Africa

    NARCIS (Netherlands)

    W. Schaftenaar (Willem); G.M.G.M. Verjans (George); S. Getu (Sarah); J.A. McIntyre (James); H.E. Struthers (Helen); A.D.M.E. Osterhaus (Albert); R.P.H. Peters (Remco)

    2014-01-01

    textabstractSeroprevalence data of human herpesviruses (HHVs) are limited for sub-Saharan Africa. These are important to provide an indication of potential burden of HHV-related disease, in particular in human immunodeficiency virus (HIV)-infected individuals who are known to be at increased risk of

  16. Feline immunodeficiency virus testing in stray, feral, and client-owned cats of Ottawa.

    Science.gov (United States)

    Little, Susan E

    2005-10-01

    Feline immunodeficiency virus (FIV) seroprevalence is evaluated in 3 groups of cats. Seventy-four unowned urban strays were tested, as well as 20 cats from a small feral cat colony, and 152 client-owned cats. Of the 246 cats tested, 161 (65%) were male and 85 (35%) were female. Seroprevalence for FIV was 23% in the urban strays, 5% in the feral cat colony, and 5.9% in the client-owned cats. Ten cats (4%) were also positive for Feline leukemia virus (FeLV) antigen, including 2 cats coinfected with FeLV and FIV. Seroprevalence for FIV in cats from Ottawa is similar to that found in other nonrandom studies of cats in North America.

  17. Mosquito Surveillance for 15 Years Reveals High Genetic Diversity Among West Nile Viruses in Israel.

    Science.gov (United States)

    Lustig, Yaniv; Hindiyeh, Musa; Orshan, Laor; Weiss, Leah; Koren, Ravit; Katz-Likvornik, Shiri; Zadka, Hila; Glatman-Freedman, Aharona; Mendelson, Ella; Shulman, Lester M

    2016-04-01

    West Nile Virus (WNV) is endemic in Israel and has been the cause of several outbreaks in recent years. In 2000, a countrywide mosquito survey was established to monitor WNV activity and characterize viral genotypes in Israel. We analyzed data from 7135 pools containing 277 186 mosquitoes collected over the past 15 years and, here, report partial sequences of WNV genomes obtained from 102 of the 336 positive mosquito pools. Phylogenetic analysis demonstrated that cluster 4 and the Mediterranean and Eastern European subtypes of cluster 2 within WNV lineage 1 circulated in Israel, as did WNV lineage 2, highlighting a high genetic diversity of WNV genotypes in our region. As a major crossroads for bird migration between Africa and Eurasia and with a long history of human infection, Israel serves as a resource hub for WNV in Africa and Eurasia and provides valuable information on WNV circulation in these regions. © The Author 2015. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail journals.permissions@oup.com.

  18. The NILE data model

    International Nuclear Information System (INIS)

    Ogg, Michael; Ricciardi, Aleta; Amoroso, A.

    1996-01-01

    NILE is a multi-disciplinary project building a distributed computing environment for HEP. Nile will provide fault-tolerant, integrated access to processing and data resources for collaborators of the CLEO experiment, though the goals and principles are applicable to many domains. Nile currently has three main objectives: a realistic distributed system architecture design, the design of a robust data model, and a Fast-Track implementation providing a prototype design environment to be used by CLEO physicists. In this paper, we describe the Data Model, its design issues, and its interactions with the NILE System Architecture. (author)

  19. Seroprevalence of Hepatitis B and C Virus Infection Among Barbers in Isfahan Province, Iran

    Directory of Open Access Journals (Sweden)

    Shoaei

    2015-08-01

    Full Text Available Background Hepatitis B virus (HBV and hepatitis C virus (HCV infections are among the most occupational hazards in the world, including Iran. Barbers have continued to expose to different infectious diseases. They may often be exposed accidentally to the blood and body fluids of their customers, through needle pricks, scissor cuts, tattooing and other beauty treatments. Objectives The aim of the present study was to determine the seroprevalence of HBV, and HCV infections and to investigate the correlation between the HBs-Ab titer and some of the risk factors in the barbers of Isfahan city, Iran. Patients and Methods This cross-sectional seroepidemiological study was performed on 479 male and female barbers during July to September 2012 in Isfahan Province, Iran. Data were collected using a self-reporting questionnaire including demographic characteristics and main risk factors for HCV and HBV infections. A 5-mL venous blood sample was obtained from each subject. The levels of antigen and antibodies (HBs Ag, HBc Ab, HBs Ab, and HCV Ab were measured by the enzyme-linked immunosorbant assay (ELISA. Data were analyzed using descriptive statistics by SPSS software, version 16. Results The mean age of the individuals was 39.6 ± 11.4 years. Two hundred and thirty-three cases (48.6% were men and 246 (51.4% were women. All the subjects were negative for HCV Ab. The seropositivity of HBV was 6.6%. No significant correlation was found between risk factors and being HBV-seropositive. Among our participants, it was found that most barbers had been exposed to razors or scissor cuts. Conclusions Our findings indicate that both HCV and HBV infections may not constitute occupational hazards for barbers; however, it is essential to promote awareness of these risks among barbers and effective HBV vaccination should be performed among them.

  20. Experimental infection of rock pigeons (Columba livia) with three West Nile virus lineage 1 strains isolated in Italy between 2009 and 2012.

    Science.gov (United States)

    Spedicato, M; Carmine, I; Bellacicco, A L; Marruchella, G; Marini, V; Pisciella, M; Di Francesco, G; Lorusso, A; Monaco, F; Savini, G

    2016-04-01

    West Nile virus (WNV) circulation dynamics in the context of the urban environment is not yet elucidated. In this perspective, three groups of eight rock pigeons (Columbia livia) were inoculated with three WNV lineage 1 strains isolated in Italy between 2009 and 2012. The pigeons did not develop any clinical signs consistent with WNV acute infection. All animals seroconverted and shed virus up to 15 days post-infection by the oral or cloacal routes. In all infected groups viraemia lasted for 4 days post-infection. No WNV-specific gross or histological lesions were found in infected birds compared to control birds and immunohistochemistry remained constantly negative from all tissues. The reservoir competence index was also assessed and it ranged between 0·11 and 0·14. This study demonstrates that pigeons are competent reservoir hosts for Italian WNV lineage 1 circulating strains thus potentially posing a risk to the public health system.

  1. Purification and crystallization of Kokobera virus helicase

    International Nuclear Information System (INIS)

    De Colibus, Luigi; Speroni, Silvia; Coutard, Bruno; Forrester, Naomi L.; Gould, Ernest; Canard, Bruno; Mattevi, Andrea

    2007-01-01

    Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method and exhibit a diffraction limit of 2.3 Å. Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. The flavivirus genus is characterized by a positive-sense single-stranded RNA genome. The unique open reading frame of the viral RNA is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the NS3 gene that encodes a C-terminal helicase domain consisting of 431 amino acids. Helicase inhibitors are potential antiviral drugs as the helicase is essential to viral replication. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method. The crystals belong to space group P3 1 21 (or P3 2 21), with unit-cell parameters a = 88.6, c = 138.6 Å, and exhibit a diffraction limit of 2.3 Å

  2. Purification and crystallization of Kokobera virus helicase

    Energy Technology Data Exchange (ETDEWEB)

    De Colibus, Luigi; Speroni, Silvia [Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100 Pavia (Italy); Coutard, Bruno [Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS et Université Aix-Marseille I et II, ESIL, Campus de Luminy, 13288 Marseille CEDEX 09 (France); Forrester, Naomi L.; Gould, Ernest [Centre for Ecology and Hydrology (formerly Institute of Virology), Mansfield Road, Oxford OX1 3SR (United Kingdom); Canard, Bruno [Architecture et Fonction des Macromolécules Biologiques, UMR 6098 CNRS et Université Aix-Marseille I et II, ESIL, Campus de Luminy, 13288 Marseille CEDEX 09 (France); Mattevi, Andrea, E-mail: mattevi@ipvgen.unipv.it [Department of Genetics and Microbiology, University of Pavia, Via Ferrata 1, 27100 Pavia (Italy)

    2007-03-01

    Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method and exhibit a diffraction limit of 2.3 Å. Kokobera virus is a mosquito-borne flavivirus belonging, like West Nile virus, to the Japanese encephalitis virus serocomplex. The flavivirus genus is characterized by a positive-sense single-stranded RNA genome. The unique open reading frame of the viral RNA is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the NS3 gene that encodes a C-terminal helicase domain consisting of 431 amino acids. Helicase inhibitors are potential antiviral drugs as the helicase is essential to viral replication. Crystals of the Kokobera virus helicase domain were obtained by the hanging-drop vapour-diffusion method. The crystals belong to space group P3{sub 1}21 (or P3{sub 2}21), with unit-cell parameters a = 88.6, c = 138.6 Å, and exhibit a diffraction limit of 2.3 Å.

  3. Synergized resmethrin and corticosterone alter the chicken's response to west nile virus

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, Mark David [Los Alamos National Laboratory; Franson, J Christian [US GEOLOGICAL SURVEY; Mostl, Erich [UNIV OF VIENNA; Porter, Warren P [UNIV OF WISCONSIN; Hofmeister, Erik K [US GEOLOGICAL SURVEY

    2009-01-01

    Debate concerning arbovirus control strategies remains contentious because concern regarding the relative risk of viral infection and environmental toxicant exposure is high but inadequately characterized. Taking this into account, mosquito control agencies employ aerial insecticides only after arbovirus surveillance data indicate high local mosquito-infection-rates. Successfully mitigating the risk of adult-mosquito-control insecticides ('adulticides') to non-target species such as humans, domestic animals, fish, beneficial insects and wildlife, while increasing their efficacy to reduce arbovirus outbreak intensity requires targeted scientific data from animal toxicity studies and environmental monitoring activities. Wild birds are an important reservoir host for WNv and are potentially exposed to insecticides used for mosquito control. However, no risk assessments have evaluated whether insecticides augment or extend the potential transmissibility of West Nile virus (WNv) in birds. In order to augment existing resmethrin risk assessments, we aimed to determine whether synergized resmethrin (SR) may cause chickens to develop an elevated or extended WN viremia and if subacute stress may affect its immunotoxicity. We distributed 40 chickens into four groups then exposed them prior to and during WNv infection with SR (50 {mu}g/l resmethrin + 150 {mu}g/l piperonyl butoxide) and/or 20 mg/I corticosterone (CORT) in their drinking-water. Corticosterone was given for 10 continuous days and SR was given for 3 alternate days starting the 3rd day of CORT exposure, then chickens were subcutaneously inoculated with WNv on the 5th day of CORT treatment. Compared to controls, CORT treatment extended and elevated viremia, enhanced WNv-specific antibody and increased the percentage of birds that shed oral virus, whereas SR treatment extended viremia, depressed WNv-specific IgG, and increased the percentage of CORT-treated birds that shed oral virus. Corticosterone and SR

  4. Animal viral diseases and global change: Bluetongue and West Nile fever as paradigms

    Directory of Open Access Journals (Sweden)

    Miguel Angel eJimenez-Clavero

    2012-06-01

    Full Text Available Environmental changes have an undoubted influence on the appearance, distribution and evolution of infectious diseases, and notably on those transmitted by vectors. Global change refers to environmental changes arising from human activities affecting the fundamental mechanisms operating in the biosphere. This paper discusses the changes observed in recent times with regard to some important arboviral (arthropod-borne viral diseases of animals, and the role global change could have played in these variations. Two of the most important arboviral diseases of animals, bluetongue and West Nile fever/encephalitis, have been selected as models. In both cases, in the last 15 years an important leap forward has been observed, which has lead to considering them emerging diseases in different parts of the world. Bluetongue, affecting domestic ruminants, has recently afflicted livestock in Europe in an unprecedented epizootic, causing enormous economic losses. West Nile fever/encephalitis affects wildlife (birds, domestic animals (equines and humans, thus, beyond the economic consequences of its occurrence, as a zoonotic disease, it poses an important public health threat. West Nile virus has expanded in the last 12 years worldwide, and particularly in the Americas, where it first occurred in 1999, extending throughout the Americas relentlessly since then, causing a severe epidemic of disastrous consequences for public health, wildlife and livestock. In Europe, West Nile virus is known long time ago, but it is since the last years of the XXth century that its incidence has risen substantially. Circumstances such as global warming, changes in land use and water management, increase in travel, trade of animals, and others, can have an important influence in the observed changes in both diseases. The following question is raised: What is the contribution of global changes to the current increase of these diseases in the world?

  5. Impact of extrinsic incubation temperature and virus exposure on vector competence of Culex pipiens quinquefasciatus Say (Diptera: Culicidae) for West Nile virus.

    Science.gov (United States)

    Richards, Stephanie L; Mores, Christopher N; Lord, Cynthia C; Tabachnick, Walter J

    2007-01-01

    Culex pipiens quinquefasciatus Say mosquitoes from a laboratory colony were exposed to artificial blood meals containing West Nile virus (WNV) and held at incubation temperatures approximating average daily temperatures that occur during Florida arboviral periods. Mosquitoes fed blood meals containing 6.2 logs plaque-forming units (pfu) WNV/mL and held at 25 degrees C, 28 degrees C, or 30 degrees C for 13 days exhibited significantly different rates of infection (30%, 52%, 93%) and dissemination (33%, 22%, 81%) across temperatures. In a separate experiment, Cx. p. quinquefasciatus mosquitoes were provided artificial blood meals with graded doses of WNV from 3.7 to 5.8 logs pfu/mL and maintained at 28 degrees C for 13 days. Rates of infection increased as a function of virus dose, but neither body titers nor dissemination rates were significantly different for mosquitoes that were infected by ingesting different amounts of WNV. Our findings indicate that efficiency of WNV infection and dissemination, and thereby transmission, in Cx. p. quinquefasciatus populations similar to our tested colony may also be diminished when fed blood meals containing less than 5.8 logs pfu WNV/mL and when environmental temperature falls below 30 degrees C. The relationship between the infection rate and dissemination rate changed at different temperatures. This relationship is likely complex and dependent on diverse interactions between factors such as incubation temperature and viremia, which should also be assessed for field populations.

  6. Herpes Simplex Virus Type-2 and Human Immunodeficiency Virus ...

    African Journals Online (AJOL)

    Objectives: To estimate the seroprevalence of Herpes Simplex Type 2 (HSV-2) and its association with Human Immunodeficiency Virus type 1 (HIV-1) infections in rural Kilimanjaro Tanzania. Methods: A cross-sectional survey was conducted in Oria village from March to June 2005 involving all individuals aged 15-44 years ...

  7. BOVINE RESPIRATORY SYNCYTIAL VIRUS EPIDEMIOLOGY AND RISK FACTORS ON CATTLE HERDS OF CAMPECHE STATE, MEXICO

    Directory of Open Access Journals (Sweden)

    Lisandro Alberto Encalada Mena

    2016-12-01

    Full Text Available High seroprevalence in Yucatan and proximity to the state of Campeche make it necessary to determine the seroprevalence and risk factors of bovine respiratory syncytial virus (VRSB in the state of Campeche, Mexico. Thus the objective of the present work was to determine the seroprevalence and risk factors bovine respiratory syncytial virus (BRSV of the state of Campeche, Mexico. The sampled of 36 cattle herds (842 sera were analyzed by indirect ELISA kit, in the 11 municipalities of Campeche. A survey to obtain risk factors (sex, age of animals, number of animals grazing density, management system, presence of sheep on the farm and access to the roadside was applied and calculated X2 for each variable considered. Of the total number of samples analyzed (842, 273 were positive (32.47%. The prevalence ranges found ranged from 0% to 84%, so in 9 of the herds there were no positive samples, indicating a 75% (27/36 of dispersion of this virus. X2 analysis indicated that all variables were significant and are risk factors regarding with respect to the variable seroprevalence of BRSV. The results indicate a wide circulation of BRSV and we suggest implement recommendations that will enable a lower spread of this virus in the cattle population.

  8. Seroprevalence of dengue virus antibodies in asymptomatic Costa Rican children, 2002-2003: a pilot study La seroprevalencia de anticuerpos contra el virus del dengue en niños costarricenses asintomáticos, 2002-2003: estudio piloto

    Directory of Open Access Journals (Sweden)

    Roberto Iturrino-Monge

    2006-07-01

    Full Text Available OBJECTIVES: Since 1993 dengue has become more frequent in Costa Rica. Adults have been the most affected population, while children have remained virtually unharmed. So far no studies have investigated how many asymptomatic children have been affected by this virus. This pilot study documents the seroprevalence, measured as the presence of IgG antibodies, of dengue virus in asymptomatic children from two different geographical areas. METHODS: This descriptive, prospective epidemiologic study compared the presence of antibodies in children who live in a coastal region of a tropical country where dengue is endemic, and an inland area where dengue is not endemic. An enzyme-linked immunosorbent assay was used to test the serum for dengue virus IgG antibodies. None of the children had a prior history of dengue, fever, immunosuppressive therapy or underlying disease. RESULTS: During the period from July 2002 to July 2003, 103 children were recruited from each area. In the costal region we found a seroprevalence of 36.9%. In the inland area seroprevalence was 2.9% CONCLUSIONS: We found a substantial number of asymptomatic infections in Costa Rican children. This greatly increases the risk of dengue hemorrhagic fever or dengue shock syndrome in these children, in whom previous dengue infection had gone undetected. Preventive efforts should be targeted at the costal region due to the higher prevalence in this area.OBJETIVOS: Desde 1993, la frecuencia de dengue en Costa Rica ha venido aumentando. La población de adultos ha sido la más afectada, mientras que en los niños apenas se han presentado casos. Hasta el momento no se han realizado estudios para determinar cuántos niños asintomáticos se han visto afectados por el virus de la enfermedad. Este estudio piloto documenta la seroprevalencia de anticuerpos de tipo IgG contra el virus del dengue en niños asintomáticos procedentes de dos zonas geográficas distintas. MÉTODOS: En este estudio

  9. Emerging mosquito-borne viruses: transmission and modulation of host defence

    NARCIS (Netherlands)

    Fros, J.J.

    2015-01-01

    Summary

    Two highly pathogenic arthropod-borne (arbo)viruses, West Nile virus (WNV) and chikungunya virus (CHIKV), recently (re-)emerged in both Europe and the Americas. This resulted in large-scale epidemics of severe encephalitic and arthritogenic human disease,

  10. Research Advances: DNA Computing Targets West Nile Virus, Other Deadly Diseases, and Tic-Tac-Toe; Marijuana Component May Offer Hope for Alzheimer's Disease Treatment; New Wound Dressing May Lead to Maggot Therapy--Without the Maggots

    Science.gov (United States)

    King, Angela G.

    2007-01-01

    This article presents three reports of research advances. The first report describes a deoxyribonucleic acid (DNA)-based computer that could lead to faster, more accurate tests for diagnosing West Nile Virus and bird flu. Representing the first "medium-scale integrated molecular circuit," it is the most powerful computing device of its type to…

  11. Awareness and practice of Human Immunodeficiency Virus And ...

    African Journals Online (AJOL)

    Background: Human Immunodeficiency Virus(HIV) and Hepatitis B Virus(HBV) infections are global viral diseases with various seroprevalence rates in different parts of the world. They share similar modes of transmission and are very important in Transfusion Medicine. Aim/Objective: To determine the level of awareness ...

  12. Antibodies to West Nile virus in asymptomatic mammals, birds, and reptiles in the Yucatan Peninsula of Mexico.

    Science.gov (United States)

    Farfán-Ale, José A; Blitvich, Bradley J; Marlenee, Nicole L; Loroño-Pino, María A; Puerto-Manzano, Fernando; García-Rejón, Julián E; Rosado-Paredes, Elsy P; Flores-Flores, Luis F; Ortega-Salazar, Andres; Chávez-Medina, Jaidy; Cremieux-Grimaldi, Juan C; Correa-Morales, Favián; Hernández-Gaona, Gerson; Méndez-Galván, Jorge F; Beaty, Barry J

    2006-05-01

    Surveillance for evidence of West Nile virus (WNV) infection in taxonomically diverse vertebrates was conducted in the Yucatan Peninsula of Mexico in 2003 and 2004. Sera from 144 horses on Cozumel Island, Quintana Roo State, 415 vertebrates (257 birds, 52 mammals, and 106 reptiles) belonging to 61 species from the Merida Zoo, Yucatan State, and 7 farmed crocodiles in Ciudad del Carmen, Campeche State were assayed for antibodies to flaviviruses. Ninety (62%) horses on Cozumel Island had epitope-blocking enzyme-linked immunosorbent assay (ELISA) antibodies to flaviviruses, of which 75 (52%) were seropositive for WNV by plaque reduction neutralization test (PRNT). Blocking ELISA antibodies to flaviviruses also were detected in 13 (3%) animals in the Merida Zoo, including 7 birds and 2 mammals (a jaguar and coyote) seropositive for WNV by PRNT. Six (86%) crocodiles in Campeche State had PRNT-confirmed WNV infections. All animals were healthy at the time of serum collections and none had a history of WNV-like illness.

  13. Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

    Science.gov (United States)

    Rossi, Carmine; Shrier, Ian; Marshall, Lee; Cnossen, Sonya; Schwartzman, Kevin; Klein, Marina B; Schwarzer, Guido; Greenaway, Chris

    2012-01-01

    International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV). We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2%) and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%). HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million) are estimated to be chronically infected with HBV. The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of international migrants can become an important component of HBV

  14. Seroprevalence of chronic hepatitis B virus infection and prior immunity in immigrants and refugees: a systematic review and meta-analysis.

    Directory of Open Access Journals (Sweden)

    Carmine Rossi

    Full Text Available BACKGROUND: International migrants experience increased mortality from hepatocellular carcinoma compared to host populations, largely due to undetected chronic hepatitis B infection (HBV. We conducted a systematic review of the seroprevalence of chronic HBV and prior immunity in migrants arriving in low HBV prevalence countries to identify those at highest risk in order to guide disease prevention and control strategies. METHODS AND FINDINGS: Medline, Medline In-Process, EMBASE and the Cochrane Database of Systematic Reviews were searched. Studies that reported HBV surface antigen or surface antibodies in migrants were included. The seroprevalence of chronic HBV and prior immunity were pooled by region of origin and immigrant class, using a random-effects model. A random-effects logistic regression was performed to explore heterogeneity. The number of chronically infected migrants in each immigrant-receiving country was estimated using the pooled HBV seroprevalences and country-specific census data. A total of 110 studies, representing 209,822 immigrants and refugees were included. The overall pooled seroprevalence of infection was 7.2% (95% CI: 6.3%-8.2% and the seroprevalence of prior immunity was 39.7% (95% CI: 35.7%-43.9%. HBV seroprevalence differed significantly by region of origin. Migrants from East Asia and Sub-Saharan Africa were at highest risk and migrants from Eastern Europe were at an intermediate risk of infection. Region of origin, refugee status and decade of study were independently associated with infection in the adjusted random-effects logistic model. Almost 3.5 million migrants (95% CI: 2.8-4.5 million are estimated to be chronically infected with HBV. CONCLUSIONS: The seroprevalence of chronic HBV infection is high in migrants from most world regions, particularly among those from East Asia, Sub-Saharan Africa and Eastern Europe, and more than 50% were found to be susceptible to HBV. Targeted screening and vaccination of

  15. Impact of West Nile virus dose and incubation period on vector competence of Culex nigripalpus (Diptera: Culicidae).

    Science.gov (United States)

    Richards, Stephanie L; Anderson, Sheri L; Lord, Cynthia C; Tabachnick, Walter J

    2011-11-01

    Female Culex nigripalpus were fed blood containing a low dose (6.3±0.01 logs plaque-forming units (PFU)/mL) or high dose (7.3±0.1 logs PFU/mL) of West Nile virus (WNV) and maintained at 28°C for incubation periods (IPs) of 6 or 12 days. Vector competence was measured using rates of infection (% with WNV-positive bodies), dissemination (% infected with WNV-positive legs), and transmission (% infected with WNV-positive saliva). Infection rates were not influenced by dose or IP. Dissemination rates were significantly higher at the high dose, and this was dependent on IP. Despite 100% infection and 90% dissemination in the most permissive treatment of high dose and 12 days, only 11% transmission was observed. Virus titers in body and leg tissues were significantly lower at the low dose and the titers were not influenced by IP. We show that not all mosquitoes with infections and/or disseminated infections transmit WNV under the conditions of this test. Therefore, characterizing the transmission ability of a vector population using infection or dissemination as indicators of transmission may provide inaccurate information. The complex relationships between infection, dissemination, and transmission must be evaluated under a variety of biological and environmental conditions to begin to assess the epidemiological risk of natural mosquito populations.

  16. When to Spray: a Time-Scale Calculus Approach to Controlling the Impact of West Nile Virus

    Directory of Open Access Journals (Sweden)

    Diana Thomas

    2009-12-01

    Full Text Available West Nile Virus (WNV made its initial appearance in the New York City (NYC metropolitan area in 1999 and was implicated in cases of human encephalitis and the extensive mortality in crows (Corvus sp. and other avian species. Mosquitoes were found to be the primary vectors and NYC's current policy on control strategies involved an eradication program that depends on the synchronicity of the summer mosquito population's increases with the occurrence of cases in humans. The purpose of this paper is to investigate whether this is the most effective control strategy because past mathematical models assumed discrete behavior that is modeled by difference equations for a single summer season was most important to the virus's life cycle. However, both surviving mosquito eggs and surviving migratory birds incubate the virus during the winter, leading to a continuation of infections in the following warmer spring and summer when the birds return and the eggs hatch. Additionally, the virulence of WNV has been observed to fluctuate with changes in temperature toward warmer conditions. Models are required that account for these multi-seasonal dynamics and time-scale calculus is a newly developed method for resolving the behavior of systems that exhibit both discrete and continuous behavior. We found that, although the static states of the new temperature delay model are no different from older models, simulations indicate that the rate of the infection is affected by avian recovery at a lower temperature threshold. Consequently, eradication strategies should consider that controlling mosquitoes during the fall when colder temperatures occur would cause a fast and efficient drop to a disease-free state. This could prove rather more effective than mosquito control in the warmer months.

  17. Sentinel pigeon surveillance for West Nile virus by using lard-can traps at differing elevations and canopy cover classes.

    Science.gov (United States)

    Deegan, Carrie S; Burns, Joseph E; Huguenin, Michael; Steinhaus, Eliza Y; Panella, Nicholas A; Beckett, Susan; Komar, Nicholas

    2005-11-01

    Sentinel pigeons, Columba livia, were installed in lard-can traps at heights of 1.5 m and 7.6-9.1 m within differing canopy cover classes in New York City. Adult mosquitoes were collected weekly from July to October 2002, as were serum samples from each pigeon. Culex pipiens L. and Culex restuans Theobald comprised 97% of mosquitoes collected and were most numerous in canopy-level, forested traps. The West Nile virus (family Flaviviridae, genus Flavivirus, WNV) seroconversion rate was significantly greater for pigeons in canopy-level traps, although seroconversions occurred concurrently with human cases in the city and were of little prognostic value to public health agencies. Our results indicate that sentinel pigeons were most effective for monitoring enzootic transmission of WNV when placed in single-sentinel caging 7.6-9.1 m above ground level.

  18. A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

    Directory of Open Access Journals (Sweden)

    Miguel A Martín-Acebes

    Full Text Available West Nile virus (WNV is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu on the highly basic internal capsid or core (C protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

  19. A single amino acid substitution in the core protein of West Nile virus increases resistance to acidotropic compounds.

    Science.gov (United States)

    Martín-Acebes, Miguel A; Blázquez, Ana-Belén; de Oya, Nereida Jiménez; Escribano-Romero, Estela; Shi, Pei-Yong; Saiz, Juan-Carlos

    2013-01-01

    West Nile virus (WNV) is a worldwide distributed mosquito-borne flavivirus that naturally cycles between birds and mosquitoes, although it can infect multiple vertebrate hosts including horses and humans. This virus is responsible for recurrent epidemics of febrile illness and encephalitis, and has recently become a global concern. WNV requires to transit through intracellular acidic compartments at two different steps to complete its infectious cycle. These include fusion between the viral envelope and the membrane of endosomes during viral entry, and virus maturation in the trans-Golgi network. In this study, we followed a genetic approach to study the connections between viral components and acidic pH. A WNV mutant with increased resistance to the acidotropic compound NH4Cl, which blocks organelle acidification and inhibits WNV infection, was selected. Nucleotide sequencing revealed that this mutant displayed a single amino acid substitution (Lys 3 to Glu) on the highly basic internal capsid or core (C) protein. The functional role of this replacement was confirmed by its introduction into a WNV infectious clone. This single amino acid substitution also increased resistance to other acidification inhibitor (concanamycin A) and induced a reduction of the neurovirulence in mice. Interestingly, a naturally occurring accompanying mutation found on prM protein abolished the resistant phenotype, supporting the idea of a genetic crosstalk between the internal C protein and the external glycoproteins of the virion. The findings here reported unveil a non-previously assessed connection between the C viral protein and the acidic pH necessary for entry and proper exit of flaviviruses.

  20. MicroRNA reduction of neuronal West Nile virus replication attenuates and affords a protective immune response in mice.

    Science.gov (United States)

    Brostoff, Terza; Pesavento, Patricia A; Barker, Christopher M; Kenney, Joan L; Dietrich, Elizabeth A; Duggal, Nisha K; Bosco-Lauth, Angela M; Brault, Aaron C

    2016-10-17

    West Nile virus (WNV) is an important agent of human encephalitis that has quickly become endemic across much of the United States since its identification in North America in 1999. While the majority (∼75%) of infections are subclinical, neurologic disease can occur in a subset of cases, with outcomes including permanent neurologic damage and death. Currently, there are no WNV vaccines approved for use in humans. This study introduces a novel vaccine platform for WNV to reduce viral replication in the central nervous system while maintaining peripheral replication to elicit strong neutralizing antibody titers. Vaccine candidates were engineered to incorporate microRNA (miRNA) target sequences for a cognate miRNA expressed only in neurons, allowing the host miRNAs to target viral transcription through endogenous RNA silencing. To maintain stability, these targets were incorporated in multiple locations within the 3'-untranslated region, flanking sequences essential for viral replication without affecting the viral open reading frame. All candidates replicated comparably to wild type WNV in vitro within cells that did not express the cognate miRNA. Insertional control viruses were also capable of neuroinvasion and neurovirulence in vivo in CD-1 mice. Vaccine viruses were safe at all doses tested and did not demonstrate mutations associated with a reversion to virulence when serially passaged in mice. All vaccine constructs were protective from lethal challenge in mice, producing 93-100% protection at the highest dose tested. Overall, this is a safe and effective attenuation strategy with broad potential application for vaccine development. Published by Elsevier Ltd.

  1. West Nile Virus: High Transmission Rate in North-Western European Mosquitoes Indicates Its Epidemic Potential and Warrants Increased Surveillance.

    Directory of Open Access Journals (Sweden)

    Jelke J Fros

    Full Text Available West Nile virus (WNV is a highly pathogenic flavivirus transmitted by Culex spp. mosquitoes. In North America (NA, lineage 1 WNV caused the largest outbreak of neuroinvasive disease to date, while a novel pathogenic lineage 2 strain circulates in southern Europe. To estimate WNV lineage 2 epidemic potential it is paramount to know if mosquitoes from currently WNV-free areas can support further spread of this epidemic.We assessed WNV vector competence of Culex pipiens mosquitoes originating from north-western Europe (NWE in direct comparison with those from NA. We exposed mosquitoes to infectious blood meals of lineage 1 or 2 WNV and determined the infection and transmission rates. We explored reasons for vector competence differences by comparing intrathoracic injection versus blood meal infection, and we investigated the influence of temperature. We found that NWE mosquitoes are highly competent for both WNV lineages, with transmission rates up to 25%. Compared to NA mosquitoes, transmission rates for lineage 2 WNV were significantly elevated in NWE mosquitoes due to better virus dissemination from the midgut and a shorter extrinsic incubation time. WNV infection rates further increased with temperature increase.Our study provides experimental evidence to indicate markedly different risk levels between both continents for lineage 2 WNV transmission and suggests a degree of genotype-genotype specificity in the interaction between virus and vector. Our experiments with varying temperatures explain the current localized WNV activity in southern Europe, yet imply further epidemic spread throughout NWE during periods with favourable climatic conditions. This emphasizes the need for intensified surveillance of virus activity in current WNV disease-free regions and warrants increased awareness in clinics throughout Europe.

  2. Seroepidemiology of hepatitis A, B, C, and E viruses infection among preschool children in Taiwan.

    Science.gov (United States)

    Lin, Jye-Bin; Lin, Ding-Bang; Chen, Shiuan-Chih; Chen, Pao-San; Chen, Wen-Kang

    2006-01-01

    Taiwan was a hyperendemic area for hepatitis A and B viruses (HAV and HBV) infection before late 1980s. To study the seroprevalence of hepatitis A, B, C, and E viruses (HCV and HEV) infection among preschool children in Taiwan, a community-based survey was carried out in 54 kindergartens in 10 urban areas, 10 rural areas, and 2 aboriginal areas randomly selected through stratified sampling. Serum specimens of 2,538 preschool children were screened for the hepatitis A, C, and E antibodies by a commercially available enzyme immunoassay and for HBV markers by radioimmunoassay methods. The multivariate-adjusted odd ratios (OR) with their 95% confidence intervals (CI) were estimated through the multiple logistic regression analysis. Females had a statistically significantly higher HAV seroprevalence than males. The seroprevalence of HCV infection increased significantly with age. The larger the sibship size, the higher the seroprevalence of HBV infection. Aboriginal children had a significantly higher seroprevalence of HBV and HEV infection and lower seroprevalence of HCV infection than non-aboriginal children. A significantly higher seroprevalence of HBV infection was found in rural children than urban children. There was no significant association between serostatus of HAV and HEV infection and between serostatus of HBV and HCV infection among preschool children in Taiwan. The poor environmental and hygienic conditions in the aboriginal areas might play a role in infection with HBV and HEV.

  3. Terminal structures of West Nile virus genomic RNA and their interactions with viral NS5 protein

    International Nuclear Information System (INIS)

    Dong Hongping; Zhang Bo; Shi Peiyong

    2008-01-01

    Genome cyclization is essential for flavivirus replication. We used RNases to probe the structures formed by the 5'-terminal 190 nucleotides and the 3'-terminal 111 nucleotides of the West Nile virus (WNV) genomic RNA. When analyzed individually, the two RNAs adopt stem-loop structures as predicted by the thermodynamic-folding program. However, when mixed together, the two RNAs form a duplex that is mediated through base-pairings of two sets of RNA elements (5'CS/3'CSI and 5'UAR/3'UAR). Formation of the RNA duplex facilitates a conformational change that leaves the 3'-terminal nucleotides of the genome (position - 8 to - 16) to be single-stranded. Viral NS5 binds specifically to the 5'-terminal stem-loop (SL1) of the genomic RNA. The 5'SL1 RNA structure is essential for WNV replication. The study has provided further evidence to suggest that flavivirus genome cyclization and NS5/5'SL1 RNA interaction facilitate NS5 binding to the 3' end of the genome for the initiation of viral minus-strand RNA synthesis

  4. In Vitro and in Vivo Evaluation of Mutations in the NS Region of Lineage 2 West Nile Virus Associated with Neuroinvasiveness in a Mammalian Model

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    Katalin Szentpáli-Gavallér

    2016-02-01

    Full Text Available West Nile virus (WNV strains may differ significantly in neuroinvasiveness in vertebrate hosts. In contrast to genetic lineage 1 WNVs, molecular determinants of pathogenic lineage 2 strains have not been experimentally confirmed so far. A full-length infectious clone of a neurovirulent WNV lineage 2 strain (578/10; Central Europe was generated and amino acid substitutions that have been shown to attenuate lineage 1 WNVs were introduced into the nonstructural proteins (NS1 (P250L, NS2A (A30P, NS3 (P249H NS4B (P38G, C102S, E249G. The mouse neuroinvasive phenotype of each mutant virus was examined following intraperitoneal inoculation of C57BL/6 mice. Only the NS1-P250L mutation was associated with a significant attenuation of virulence in mice compared to the wild-type. Multiplication kinetics in cell culture revealed significantly lower infectious virus titres for the NS1 mutant compared to the wild-type, as well as significantly lower amounts of positive and negative stranded RNA.

  5. Seroprevalence study of HCV among hospitalized intravenous drug users in Ahvaz, Iran (2001–2006

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    Seyed Mohammad Alavi

    Full Text Available Summary: Background and aims: Prevalence of hepatitis C virus (HCV in intravenous drug users (IDU varies in different areas according to socioeconomic and geographical circumstances. The present study was performed to determine seroprevalence of HCV in IDU individuals in Ahvaz, Iran. Materials and methods: 142 IDU patients were included in this retrospective study in Ahvaz southwest Iran from 2001 to 2006. Patients were placed in two groups determined by HCV Ab positive or negative status. Data were analyzed using SPSS for Windows (version 11.5; SPSS Inc., USA software. Results: Out of total 142 cases, 74 persons (52.11% had a positive HCV-Ab test according to the ELISA method. There was no difference in age, sex, level of education, residency and co-infection with HIV and hepatitis B virus between HCV-Ab positive (HAP and HCV-Ab negative (HAN groups (p > 0.05. HCV-Ab positivity was significantly related to imprisonment and duration spent in prison [OR: 3.22, 95% (CI 2.61–3.76, p < 0.0001]. Conclusion: Patients with IDU constitute a high-risk group for acquisition of HCV infection. Transmission of HCV via sharing syringe and needle as well as blood transfusion has been a significant source of hepatitis C infection for patients with intravenous drug addiction. Keywords: Intravenous drug user, Hepatitis C virus, Seroprevalence, Ahvaz

  6. Acute flaccid paralysis due to West nile virus infection in adults: A paradigm shift entity

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    Boby Varkey Maramattom

    2014-01-01

    Full Text Available Three cases of acute flaccid paralysis (AFP with preceding fever are described. One patient had a quadriparesis with a florid meningoencephalitic picture and the other two had asymmetric flaccid paralysis with fasciculations at the onset of illness. Magnetic resonance imaging in two cases showed prominent hyperintensitities in the spinal cord and brainstem with prominent involvement of the grey horn (polio-myelitis. Cerebrospinal fluid (CSF polymerase chain reaction was positive for West Nile virus (WNV in the index patient. All three cases had a positive WNV immunoglobulin M antibody in serum/CSF and significantly high titer of WNV neutralizing antibody in serum, clearly distinguishing the infection from other Flaviviridae such as Japanese encephalitis. WNV has been recognized in India for many decades; however, AFP has not been adequately described. WNV is a flavivirus that is spread by Culex mosquitoes while they take blood meals from humans and lineage 1 is capable of causing a devastating neuro-invasive disease with fatal consequences or severe morbidity. We describe the first three laboratory confirmed cases of WNV induced AFP from Kerala and briefly enumerate the salient features of this emerging threat.

  7. Land cover variation and West Nile virus prevalence: Patterns, processes, and implications for disease control

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    Ezenwa, V.O.; Milheim, L.E.; Coffey, M.F.; Godsey, M.S.; King, R.J.; Guptill, S.C.

    2007-01-01

    Identifying links between environmental variables and infectious disease risk is essential to understanding how human-induced environmental changes will effect the dynamics of human and wildlife diseases. Although land cover change has often been tied to spatial variation in disease occurrence, the underlying factors driving the correlations are often unknown, limiting the applicability of these results for disease prevention and control. In this study, we described associations between land cover composition and West Nile virus (WNV) infection prevalence, and investigated three potential processes accounting for observed patterns: (1) variation in vector density; (2) variation in amplification host abundance; and (3) variation in host community composition. Interestingly, we found that WNV infection rates among Culex mosquitoes declined with increasing wetland cover, but wetland area was not significantly associated with either vector density or amplification host abundance. By contrast, wetland area was strongly correlated with host community composition, and model comparisons suggested that this factor accounted, at least partially, for the observed effect of wetland area on WNV infection risk. Our results suggest that preserving large wetland areas, and by extension, intact wetland bird communities, may represent a valuable ecosystem-based approach for controlling WNV outbreaks. ?? Mary Ann Liebert, Inc.

  8. Seroprevalencia de la infección por el virus herpes simplex tipo 2 en tres grupos poblacionales de la Ciudad de México Herpes simplex virus type 2 seroprevalence among three female population groups from Mexico City

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    Carlos J Conde-González

    2003-01-01

    ísticas relacionadas al contacto con el virus herpes simplex tipo 2 para las subpoblaciones estudiadas correspondieron, como era de esperarse, a los antecedentes del estilo de vida sexual y a la probabilidad de infección que confiere la mayor edad.OBJECTIVE: To determine the seroprevalence of type 2 herpes simplex virus (HSV-2 infection and risk factors in three female population groups in Mexico City. MATERIAL AND METHODS: A cross-sectional study was carried out in 2000, among a sample population of women living in Mexico City, diagnosed with breast or cervical cancer, and women with negative Pap test results from the general population. Informed consent was obtained from all participants to answer a sociodemographic and sex life questionnaire and draw a blood specimen. The presence of antibodies against type 2 herpes simplex virus was determined using the type-specific Western blot technique. Crude and adjusted statistical analyses were performed on the associations between survey data and infection outcomes. RESULTS: Women with cervical cancer had a seroprevalence of HSV-2 infection of 46.8% (191/408; that of women from the general population who were Pap negative was 29.3% (214/730. For women with breast cancer, the seroprevalence was 22.6% (29/128. Variables significantly associated with seropositivity against HSV-2 infection were older age, more sexual partners, having cervical cancer, and, among cervical cancer patients, beginning sexual activity before 21 years of age and being divorced or separated. CONCLUSIONS: Study findings showed statistically significant differences in the prevalence of viral infection by population groups. The overall frequency of viral infection among study subjects shows that this is an intermediate risk population, as compared with other population groups in Mexico at high (sexual workers and low (college students risk. The main characteristics associated with exposure to type 2 herpes simplex virus for the subpopulations corresponded, as expected

  9. Occurrence of avian Plasmodium and West Nile virus in culex species in Wisconsin

    Science.gov (United States)

    Hughes, T.; Irwin, P.; Hofmeister, E.; Paskewitz, S.M.

    2010-01-01

    The occurrence of multiple pathogens in mosquitoes and birds could affect the dynamics of disease transmission. We collected adult Culex pipiens and Cx. restuans (Cx. pipiens/restuans hereafter) from sites in Wisconsin and tested them for West Nile virus (WNV) and for avian malaria (Plasmodium). Gravid Cx. pipiens/restuans were tested for WNV using a commercial immunoassay, the RAMP?? WNV test, and positive results were verified by reverse transcriptasepolymerase chain reaction. There were 2 WNV-positive pools of Cx. pipiens/restuans in 2006 and 1 in 2007. Using a bias-corrected maximum likelihood estimation, the WNV infection rate for Cx. pipiens/restuans was 5.48/1,000 mosquitoes in 2006 and 1.08/1,000 mosquitoes in 2007. Gravid Cx. pipiens or Cx. restuans were tested individually for avian Plasmodium by a restriction enzymebased assay. Twelve mosquitoes were positive for avian Plasmodium (10.0), 2 were positive for Haemoproteus, and 3 were positive for Leucocytozoon. There were 4 mixed infections, with mosquitoes positive for >1 of the hemosporidian parasites. This work documents a high rate of hemosporidian infection in Culex spp. and illustrates the potential for co-infections with other arboviruses in bird-feeding mosquitoes and their avian hosts. In addition, hemosporidian infection rates may be a useful tool for investigating the ecological dynamics of Culex/avian interactions. ?? 2010 by The American Mosquito Control Association, Inc.

  10. Feline immunodeficiency virus testing in stray, feral, and client-owned cats of Ottawa

    OpenAIRE

    Little, Susan E.

    2005-01-01

    Feline immunodeficiency virus (FIV) seroprevalence is evaluated in 3 groups of cats. Seventy-four unowned urban strays were tested, as well as 20 cats from a small feral cat colony, and 152 client-owned cats. Of the 246 cats tested, 161 (65%) were male and 85 (35%) were female. Seroprevalence for FIV was 23% in the urban strays, 5% in the feral cat colony, and 5.9% in the client-owned cats. Ten cats (4%) were also positive for Feline leukemia virus (FeLV) antigen, including 2 cats coinfected ...

  11. Spatial distribution of West Nile virus in humans and mosquitoes in Israel, 2000-2014.

    Science.gov (United States)

    Lustig, Yaniv; Kaufman, Zalman; Mendelson, Ella; Orshan, Laor; Anis, Emilia; Glazer, Yael; Cohen, Daniel; Shohat, Tamy; Bassal, Ravit

    2017-11-01

    Israel has a long history of West Nile virus (WNV) morbidity, and the rate of detection of WNV in mosquitoes has been high since 2000. The aim of this study was to integrate several WNV datasets in order to gain an insight into the geographical distribution of WNV in Israel. Three choropleth maps were generated showing WNV human morbidity, WNV prevalence in mosquitoes, and the results of a nationwide serological survey, based on the division of Israel into 15 sub-districts. The maps show a high endemicity of WNV in Israel. In respect to the morbidity map, the population residing in the central part of the country and in Arava Region is at higher risk of developing the disease than the population of the rest of Israel. Interestingly, high prevalence rates of both WNV serology and WNV-infected mosquitoes were detected in Arava Region, but lower prevalence rates were detected in most areas of the coastal region, suggesting that other factors might also be important in the development of symptomatic WNV infections. These results underline the high prevalence of WNV in Israel and point to specific risk areas for WNV infections across the country. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  12. Is seroprevalence of hepatitis B and C among blood donors changing in Northern Pakistan?

    International Nuclear Information System (INIS)

    Butt, T.; But, B.

    2017-01-01

    Objective: To determine seroprevalence of hepatitis B and C among blood donors in 2009 and comparing with the seroprevalence in 2014. Study Design: Cross sectional study with retrospective data collection. Place and Duration of Study: Foundation University Medical College and Fauji Foundation Hospital, Rawalpindi. Data in 2009 and in 2014 were collected. Material and Methods: The blood samples collected from individuals from Province of Khyber Pakhtunkhawa, Azad Kashmir and Northern Punjab including Rawalpindi-Islamabad and comprised 3776 (in the year 2009) and 6740 (in the year 2014) adults ranging from 18 to 60 years who reported to Fauji Foundation Hospital, Rawalpindi voluntarily or as a compulsion to donate blood for their patients. Results: During 2009, there were 71 (1.88 percent) and 113 (2.99 percent) donors positive for hepatitis B surface antigen (HBsAg) and anti hepatitis C virus (Anti HCV) respectively out of a total of 3776 donors whereas during 2014 there were 106 (1.57 percent) and 174 (2.58 percent) donors positive for HBsAg and anti HCV respectively out of a total donors of 6740. There was no statistical significant difference between the year (2009 and 2014) and seroprevalence of HBsAg (p=0.239) and HCV positive donors (p=0.215). Conclusion: There is no significant change in seroprevalence of hepatitis B and C among blood donors during 2014 as compared to 2009 in Northern Pakistan. (author)

  13. Anticuerpos frente a virus West nile y otros virus transmitidos por artropodos en la poblacion del Delta del Ebro

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    Lozano Alvaro

    1998-01-01

    Full Text Available FUNDAMENTOS: El virus West Nile (VWN es un Flavivirus que se transmite al hombre a través de distintas especies de mosquitos y produce brotes y casos esporádicos de enfermedad en distintas regiones del Viejo Mundo, incluída la Cuenca Mediterránea. Las zonas húmedas europeas que acogen aves migratorias procedentes de África constituyen áreas de alto riesgo para esta infección, así como para otras infecciones víricas transmitidas por artrópodos. MÉTODOS: Con objeto de investigar la prevalencia de la infección por el VWN y otros virus de transmisión similar en la población humana del Delta del Ebro, se estudiaron 1037 muestras de suero, obtenidas en 10 localidades de la zona, para presencia de anticuerpos frente a VWN y otros 12 virus transmitidos por artrópodos (3 Alfavirus, 8 Flaviviridae y 1 Bunyaviridae mediante titulación por inhibición de la hemaglutinación (IHA. En algunos casos se estudió la presencia de IgM específica por IHA tras fraccionar el suero por centrifugación en gradientes de sacarosa. RESULTADOS: En total, se encontró reactividad significativa frente a alguno de los virus probados en 130 casos (12.5%; 4.1% frente a Alfavirus, 8.0% frente a Flaviviridae y 0.4% frente a Bunyaviridae. El análisis de los títulos de anticuerpos reveló porcentajes significativos de muestras con títulos elevados frente a antígenos de VWN y otros. La distribución de la seroprevalencia fue muy desigual, concentrándose fundamentalmente en 3 localidades del interior del Delta (Ampolla, San Jaime y Montells, donde la prevalencia de anticuerpos frente a Flaviviridae llegó a alcanzar el 30% y se observaron niveles residuales de IgM frente a VWN en algunos sueros. CONCLUSIONES: Estos resultados y los obtenidos previamente en otras regiones de la Península Ibérica sugieren que el VWN circula en la población humana de las zonas de riesgo y produce brotes epidémicos periódicos. Habida cuenta del alto porcentaje de

  14. Seroprevalence and diagnosis of HIV, HBV, HCV and syphilis infections among blood donors.

    Science.gov (United States)

    Tafesse, Tadesse Bekele; Gebru, Addis Adera; Gobalee, Semgne; Belay, Gosaye Degu; Belew, Molla Teferi; Ataro, Demelash; Ebrahim, Belay Ali; Shebeshi, Getachew Mekonnon; Yimam, Yonas

    2017-01-01

    Blood transfusion is one of the most important therapeutic options of life-saving intervention for recipients who are in diseased or non-diseased conditions with severe blood loss. However, it is associated with certain risks which can lead to adverse consequences that may cause acute or delayed complications and bring the risk of transfusion-transmissible infections including HIV, Hepatitis B & C and Syphilis. So, there might be a fatal risk instead of life saving. This paper aims to provide a comprehensive and reliable tabulation of available data on seroprevalence and diagnosis of HIV, HBV, HCV and Syphilis infections among blood donors. We searched studies reporting the prevalence rate of HIV, HBV, HCV and Syphilis infections among blood donors that were published between October 2009 and June 2016, using databases of PubMed, Scopus, MEDLINE, Elsevier, ScienceDirect, EBSCO, Google Scholar, EMBASE, and Web of Science with keywords: ``Hepatitis C Virus'', ``Hepatitis B Virus'', ``HIV'', ``Syphilis'', ``Seroprevalence'', and ``blood donor''. The seroprevalence of HBV and HCV was highest in African countries as compared to others continents, predominantly the West African region with a range of 10.0% to 14.96% and 1.5% to 8.69%, respectively, while the overall seropositivity of HIV and syphilis infection show a significant declining pattern through successive years globally, even though relatively higher prevalence rate was observed among older age and those with low level of education. There is a problem during selection, diagnoses and screening process in developing nations primarily due to shortage of sensitive screening test kits, highly qualified human resource and lack of proper standard operating procedures and hence, the safety of blood and blood products are the primary threats in the region. Proper clinical diagnosis and screening method should be applied during blood donation and therefore, all the donated blood should be screened properly for

  15. SEROPREVALENCE OF HEPATITIS C AMONG THE APPARENTLY HEALTHY BLOOD DONORS OF KARACHI

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    Maeesa Wadood

    2017-06-01

    Full Text Available Hepatitis C is a global health issue. Pakistan is among the prevalent countries for hepatitis C virus (HCV. Due to poverty, unemployment, low literacy rate, unawareness and poor health facilities, Pakistani population are susceptible to HCV transmission. As blood transfusion is a potential source of HCV; therefore, this study was designed to determine the recent seroprevalence of HCV among the healthy blood donors of Karachi, Pakistan. For this purpose, 536 blood donors were screened for anti- HCV antibodies by 3rd generation ELISA. The seroprevalence of HCV observed is 2.99% among healthy blood donors. Male predominance is noticed with seropositivity of 2.62%; however, only 0.37% female blood donors were reactive for anti-HCV antibodies. This study concludes that HCV frequency has been increased in the natives of Karachi, Pakistan when compared to the past studies. Therefore, it is recommended that the healthcare authorities should play a vital role in enforcing preventive measures for HCV transmission.

  16. OAS1 polymorphisms are associated with susceptibility to West Nile encephalitis in horses.

    Directory of Open Access Journals (Sweden)

    Jonathan J Rios

    Full Text Available West Nile virus, first identified within the United States in 1999, has since spread across the continental states and infected birds, humans and domestic animals, resulting in numerous deaths. Previous studies in mice identified the Oas1b gene, a member of the OAS/RNASEL innate immune system, as a determining factor for resistance to West Nile virus (WNV infection. A recent case-control association study described mutations of human OAS1 associated with clinical susceptibility to WNV infection. Similar studies in horses, a particularly susceptible species, have been lacking, in part, because of the difficulty in collecting populations sufficiently homogenous in their infection and disease states. The equine OAS gene cluster most closely resembles the human cluster, with single copies of OAS1, OAS3 and OAS2 in the same orientation. With naturally occurring susceptible and resistant sub-populations to lethal West Nile encephalitis, we undertook a case-control association study to investigate whether, similar to humans (OAS1 and mice (Oas1b, equine OAS1 plays a role in resistance to severe WNV infection. We identified naturally occurring single nucleotide mutations in equine (Equus caballus OAS1 and RNASEL genes and, using Fisher's Exact test, we provide evidence that mutations in equine OAS1 contribute to host susceptibility. Virtually all of the associated OAS1 polymorphisms were located within the interferon-inducible promoter, suggesting that differences in OAS1 gene expression may determine the host's ability to resist clinical manifestations associated with WNV infection.

  17. Seroprevalence and correlates of human T-cell lymphoma/leukemia virus type 1 antibodies among pregnant women at the University of Nigeria Teaching Hospital, Enugu, Nigeria

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    Okoye AE

    2014-09-01

    Full Text Available Augustine Ejike Okoye,1 Obike Godswill Ibegbulam,2 Robinson Chukwudi Onoh,3 Paul Olisaemeka Ezeonu,3 Ngozi I Ugwu,1 Lucky Osaheni Lawani,3 Chukwudi Simon Anigbo,2 Charles E Nonyelu21Department of Haematology and Immunology, Federal Teaching Hospital, Abakaliki, 2Department of Haematology and Immunology, University of Nigeria Teaching Hospital (UNTH, Ituku-Ozalla, 3Department of Obstetrics and Gynaecology, Federal Teaching Hospital, Abakaliki, NigeriaBackground: Human T-cell lymphoma/leukemia virus (HTLV-1 is a retrovirus transmitted vertically from mother to child parenterally and sexually by infected lymphocytes.Objective: The objective of this study was to determine the seroprevalence of HTLV-1 antibodies and associated risk factors for HTLV-1 infection among pregnant women in University of Nigeria Teaching Hospital, Enugu, southeast Nigeria.Materials and methods: A cross-sectional study was carried out from July to October 2010. Two hundred pregnant women were recruited consecutively from the antenatal clinic. Five milliliters of blood was collected from each of the participants into a plain sterile bottle and allowed to clot. The serum obtained was stored at -20°C until required for analysis. The serum samples were then analyzed for antibodies to HTLV-1 using a one-step incubation double-antigen sandwich enzyme-linked immunosorbent assay kit. Participants' demographic characteristics and degree of exposure to the risk factors associated with HTLV-1 infection were captured using a questionnaire. Statistical analysis of results was done using SPSS version 17.Results: The average age of the pregnant women was 28.94 years (standard deviation 4.17. The age-group with the highest representation was those between the ages of 26 and 30 years. Thirty-six percent of the population was above 30 years old. The result of the tests showed that only one respondent, a 31-year-old pregnant woman tested positive for HTLV-1 antibodies. Therefore, the

  18. Influence of border disease virus (BDV) on serological surveillance within the bovine virus diarrhea (BVD) eradication program in Switzerland.

    Science.gov (United States)

    Kaiser, V; Nebel, L; Schüpbach-Regula, G; Zanoni, R G; Schweizer, M

    2017-01-13

    In 2008, a program to eradicate bovine virus diarrhea (BVD) in cattle in Switzerland was initiated. After targeted elimination of persistently infected animals that represent the main virus reservoir, the absence of BVD is surveilled serologically since 2012. In view of steadily decreasing pestivirus seroprevalence in the cattle population, the susceptibility for (re-) infection by border disease (BD) virus mainly from small ruminants increases. Due to serological cross-reactivity of pestiviruses, serological surveillance of BVD by ELISA does not distinguish between BVD and BD virus as source of infection. In this work the cross-serum neutralisation test (SNT) procedure was adapted to the epidemiological situation in Switzerland by the use of three pestiviruses, i.e., strains representing the subgenotype BVDV-1a, BVDV-1h and BDSwiss-a, for adequate differentiation between BVDV and BDV. Thereby the BDV-seroprevalence in seropositive cattle in Switzerland was determined for the first time. Out of 1,555 seropositive blood samples taken from cattle in the frame of the surveillance program, a total of 104 samples (6.7%) reacted with significantly higher titers against BDV than BVDV. These samples originated from 65 farms and encompassed 15 different cantons with the highest BDV-seroprevalence found in Central Switzerland. On the base of epidemiological information collected by questionnaire in case- and control farms, common housing of cattle and sheep was identified as the most significant risk factor for BDV infection in cattle by logistic regression. This indicates that pestiviruses from sheep should be considered as a source of infection of domestic cattle and might well impede serological BVD surveillance.

  19. Decrease in seroprevalence of Hepatitis A after the implementation of nationwide disposable tableware use in Taiwan

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    Kan Wei-Chih

    2010-11-01

    Full Text Available Abstract Background Taiwan is an endemic area of viral hepatitis, including hepatitis A, which is transmitted mainly from the fecal-oral route. In order to reduce the transmission through food intake, the government implemented a policy of nationwide disposal tableware use in public eating places in 1982. We conducted a study to estimate the seroprevalence of Hepatitis A in a group of workers in Taiwan in 2005, determine the risk factors, and compare seroprevalence to published estimates in Taiwan to evaluate changes in the seroprevalence after the implementation of the nationwide disposal tableware use. Methods We recruited workers of an industrial park during their annual health examinations in 2005 and measured their anti-hepatitis A virus IgG titer using microparticle enzyme immunoassay. We compared the seroprevalence across different birth cohorts within the study population and also analyzed data from previous studies. Results The overall sero-positive rate was 22.0% in the 11,777 participants. The rate was much lower among those who were covered by the program since birth (born after 1982 in comparison with those who were not (2.7% vs. 25.3%, p Conclusions Data from both the current and previous studies in different time periods supported the effectiveness of disposal tableware in preventing the transmission of hepatitis A.

  20. Seroprevalence of hepatitis-b and c among the patients reporting in surgical opd at fauji foundation hospital, rawalpindi

    International Nuclear Information System (INIS)

    Chaudhary, I.A.; Alvi, A.A.

    2007-01-01

    To find out the seroprevalence of HbsAg and Anti HCV virus among the patients reporting in surgical OPD. This is a prospective observational study. Patients reporting to surgical OPD of Fuji Foundation Hospital, Rawalpindi above 20 years of age, with no previous history of seropositive Hepatitis B or C of chronic liver disease were enrolled from January 2006 to June 2006 Prevalence of Hepatitis B is 2.28% with a male predominance of 8.60%. Seroprevalence of Hepatitis C is 7.56% with male predominance of 10.84%. Prevalence of Hepatitis B and C is not uncommon in our country. To control its further spread public awareness and health education programs should be started at all levels. (author)

  1. Hepatitis B seroprevalence in Latin America

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    Thêmis R. Silveira

    1999-12-01

    Full Text Available The seroprevalence of hepatitis B was investigated in over 12 000 subjects in six countries of Latin America: Argentina, Brazil, Chile, the Dominican Republic, Mexico, and Venezuela. Each study population was stratified according to age, gender, and socioeconomic status. Antibodies against hepatitis B core antigen (anti-HBc were measured in order to determine hepatitis B infection. The highest overall seroprevalence was found in the Dominican Republic (21.4%, followed by Brazil (7.9%, Venezuela (3.2%, Argentina (2.1%, Mexico (1.4%, and Chile (0.6%. In all the countries an increase in seroprevalence was found among persons 16 years old and older, suggesting sexual transmission as the major route of infection. In addition, comparatively high seroprevalence levels were seen at an early age in the Dominican Republic and Brazil, implicating a vertical route of transmission.

  2. Evaluation of bovine viral diarrhea virus in New World camelids.

    Science.gov (United States)

    Wentz, Philip A; Belknap, Ellen B; Brock, Kenneth V; Collins, James K; Pugh, David G

    2003-07-15

    To determine the effect of experimental infection with bovine viral diarrhea virus (BVDV) on llamas and their fetuses, evaluate seroprevalence of BVDV in llamas and alpacas, and genetically characterize BVDV isolates from llamas. Prospective study. 4 pregnant llamas for the experimental infection study and 223 llamas and alpacas for the seroprevalence study. Llamas (seronegative to BVDV) were experimentally infected with a llama isolate of BVDV via nasal aerosolization. After inoculation, blood samples were collected every other day for 2 weeks; blood samples were obtained from crias at birth and monthly thereafter. For the seroprevalence study, blood was collected from a convenience sample of 223 camelids. Isolates of BVDV were characterized by reverse transcription-polymerase chain reaction assay. Viremia and BVDV-specific antibody response were detected in the experimentally infected llamas, but no signs of disease were observed. No virus was detected in the crias or aborted fetus, although antibodies were evident in crias after colostrum consumption. Seroprevalence to BVDV was 0.9% in llamas and alpacas. Sequences of the llama BVDV isolates were comparable to known bovine isolates. Findings suggest that llamas may be infected with BVDV but have few or no clinical signs. Inoculation of llamas during gestation did not result in fetal infection or persistent BVDV infection of crias. Seroprevalence to BVDV in llamas and alpacas is apparently low. The most likely source for BVDV infection in camelids may be cattle.

  3. Serologic survey of humans for Flavivirus West Nile in southern Moravia (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Hubálek, Zdeněk; Kříž, B.; Halouzka, Jiří

    2011-01-01

    Roč. 19, č. 3 (2011), s. 131-133 ISSN 1210-7778 R&D Projects: GA AV ČR IAA600930611 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : West Nile virus * Flavivirus * Moravia * serosurvey Subject RIV: FN - Epidemiology, Contagious Diseases ; Clinical Immunology http://www.szu.cz/svi/cejph/show_en.php?kat=archiv/2011-3-03

  4. Seroprevalence of Epstein-Barr Virus, Cytomegalovirus, and Polyomaviruses in Children with Inflammatory Bowel Disease.

    Science.gov (United States)

    Hradsky, Ondrej; Copova, Ivana; Zarubova, Kristyna; Durilova, Marianna; Nevoral, Jiri; Maminak, Miroslav; Hubacek, Petr; Bronsky, Jiri

    2015-11-01

    Young age and thiopurine therapy are risk factors for lymphoproliferative disease among patients with inflammatory bowel disease (IBD). The aims of this study were to evaluate the prevalence of seropositivity for the Epstein-Barr virus (EBV) and human cytomegalovirus (CMV) among children and adolescents with IBD, to assess the viral load of EBV, CMV, and BK and JC polyomaviruses (BKV, JCV) in these patients, and to assess the influence of different therapeutic regimens on seroprevalence and viral load. Children who had been followed in our center were tested for EBV, CMV, BKV, and JCV in a cross-sectional study. One hundred and six children were included who had Crohn's disease (68%), ulcerative colitis (29%), and unclassified IBD (3%). We found that 64% of patients were EBV seropositive. The proportion of EBV seropositive patients increased during childhood. Azathioprine therapy (p = 0.003) was associated with EBV seropositivity in a multiple logistic regression model, after adjusting for gender, age, and disease activity at determination. We found a significant association between the number of polymerase chain reaction copies and infliximab dose (p = 0.023). We did not find any significant association between CMV serology and CMV, BKV, or JCV viral load, or any other therapeutic regimen or clinical characteristics. Treatment with azathioprine appears to be a risk factor for early EBV seropositivity in children with IBD, and the infliximab dose was associated with a higher EBV viral load.

  5. Seroprevalence of simian immunodeficiency virus in wild and captive born Sykes' monkeys (Cercopithecus mitis in Kenya

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    Otsyula Moses G

    2004-10-01

    Full Text Available Abstract Background The Sykes' monkey and related forms (Cercopithecus mitis make up an abundant, widespread and morphologically diverse species complex in eastern Africa that naturally harbors a distinct simian immunodeficiency virus (SIVsyk. We carried out a retrospective serological survey of SIV infection from both wild and captive Sykes' monkeys from Kenya. We compared two commercially available, cross-reactive ELISA tests using HIV antigens with a novel SIVsyk antigen-specific Western blot assay and analyzed the data by origin, subspecies, age and sex. Results The SIVsyk antigen-specific Western blot assay detected more serum samples as positive than either of the cross-reactive ELISA assays. Using this assay, we found that seroprevalence is higher than previously reported, but extremely variable in wild populations (from 0.0 to 90.9%. Females were infected more often than males in both wild and captive populations. Seropositive infants were common. However, no seropositive juveniles were identified. Conclusion We have developed a specific and sensitive Western blot assay for anti-SIVsyk antibody detection. Sykes' monkeys are commonly infected with SIVsyk, but with extremely variable prevalence in the wild. Higher infection prevalence in females suggests predominantly sexual transmission. High infection prevalence in infants, but none in juveniles, suggests maternal antibodies, but little or no vertical transmission.

  6. A serological survey for avian infectious bronchitis virus and Newcastle disease virus antibodies in backyard (free-range) village chickens in Mexico.

    Science.gov (United States)

    Gutierrez-Ruiz, E J; Ramirez-Cruz, G T; Camara Gamboa, E I; Alexander, D J; Gough, R E

    2000-12-01

    The commercial flocks in Yucatan, Mexico are free of Newcastle disease virus (NDV) in its velogenic viscerotropic form, but little is known about the disease status of backyard poultry. A seroprevalence survey in 30 villages using haemagglutination inhibition (HI) tests for infectious bronchitis virus (IBV) and NDV antibodies was carried out from December 1997 to June 1998. The seroprevalences were 56.5% (95% CI 50-63%) for IBV and 2.2% (95% CI 0.5-3.8%) for NDV. All the villages had chickens that were positive for antibodies to IBV and nine of the villages had chickens that were positive for antibodies to NDV. This suggests that IBV may be responsible for a large proportion of the respiratory disease observed in backyard chickens in Yucatan. The implications of these findings are discussed, including the highly susceptible status of the backyard chickens in Yucatan to NDV and the possibility of this virus being one cause of the syndrome known as mortandad by the local people.

  7. Effects of West Nile virus dose and extrinsic incubation temperature on temporal progression of vector competence in Culex pipiens quinquefasciatus.

    Science.gov (United States)

    Anderson, Sheri L; Richards, Stephanie L; Tabachnick, Walter J; Smartt, Chelsea T

    2010-03-01

    Culex pipiens quinquefasciatus were fed blood containing either 7.0 +/- 0.1 logs plaque-forming units (pfu)/ml (high dose) or 5.9 +/- 0.1 logs pfu/ml (low dose) of West Nile virus and held at extrinsic incubation temperatures (EIT) of 28 degrees C or 25 degrees C. Approximately 20 mosquitoes per dose were collected after incubation periods (IP) of 4, 6, 8, and 12 days postinfection (dpi). Infection rates were influenced by EIT and virus dose but not by IP. Body titer was significantly higher for mosquitoes fed the high dose and held at 28 degrees C at the later IPs (6, 8, and 12 dpi). However, leg titer was significantly higher for mosquitoes at the later IPs but did not differ between EITs or doses. Because infection rates varied with EIT and dose, there is likely a midgut infection barrier influenced by these factors that is not influenced by IP. Dissemination rates were influenced by all 3 factors consistent with the presence of a midgut escape barrier. Dissemination rate, body titer, and leg titer were dependent on IP, indicating the need to investigate multiple time points in vector competence studies to elucidate critical events in infection and dissemination.

  8. Utilizing hunter harvest effort to survey for wildlife disease: a case study of West Nile virus in greater sage-grouse

    Science.gov (United States)

    Dusek, Robert J.; Hagen, Christian A.; Franson, J. Christian; Budeau, David A.; Hofmeister, Erik K.

    2014-01-01

    Greater sage-grouse (Centrocercus urophasianus; sage-grouse) are highly susceptible to infection with West Nile virus (WNV), with substantial mortality reported in wild populations and in experimentally infected birds. Although sage-grouse are hunted throughout much of their range, they have also recently been considered for protection under the Endangered Species Act. We used blood samples collected on filter-paper strips during the 2006–2010 Oregon, USA, annual sage-grouse hunt to survey for specific WNV-neutralizing antibodies that indicate a previous infection with WNV. During this period, hunters submitted 1,880 blood samples from sage-grouse they harvested. Samples obtained were proportional for all 12 Oregon sage-grouse hunting units. Laboratory testing of 1,839 samples by the WNV epitope-blocking enzyme-linked immunosorbent assay (bELISA) followed by plaque reduction neutralization test on bELISA-positive samples yielded 19 (1%) and 1 (0.05%) positive samples, respectively. These data provided early baseline information for future comparisons regarding the prevalence of WNV-specific neutralizing antibodies in sage-grouse in Oregon. This methodology may provide other states where sage-grouse (or other species) populations are hunted and where WNV constitutes a species conservation concern with a viable option to track the relative prevalence of the virus in populations.

  9. The White Nile as a source for Nile sediments: Assessment using U-Pb geochronology of detrital rutile and monazite

    Science.gov (United States)

    Be'eri-Shlevin, Yaron; Avigad, Dov; Gerdes, Axel

    2018-04-01

    Basement terranes exposed at the headwaters of the White Nile include Archean-Paleoproterozoic rocks of the Congo Craton, whose northern sectors were severely reworked during Neoproterozoic orogeny. New U-Pb analyses of detrital rutile and monazite from early Quaternary to Recent coastal quartz sands of Israel, at the northeast extension of the Nile sedimentary system, yield mostly late Neoproterozoic ages, with a dominant peak at ca. 600 Ma. While derivation from the reworked sectors of the Craton cannot be negated, the absence of pre-Neoproterozoic rutile and monazite indicates that the detrital contribution from the Congo cratonic nuclei into the main Nile was insignificant. The near absence of White Nile basement-derived heavy minerals from the Nile sands arriving at the Eastern Mediterranean may be explained by a number of factors such as relatively minor erosion of the Cratonic basement nuclei during the Quaternary, late connection of the White Nile to the main Nile system with a possibility that northern segments connected prior to more southerly ones, and a long-term effective sediment blockage mechanism at the mouth of White Nile. Likewise, our previous study demonstrated that Nile sands display a detrital zircon U-Pb-Hf pattern consistent with significant recycling of NE African Paleozoic sediments. It is thus plausible that any detrital contribution from White Nile basement rocks was thoroughly diluted by eroded Paleozoic sediments, or their recycled products, which were likely the greatest sand reservoir in the region. This study adds to previous studies showing the advantage of a multi mineral U-Pb geochronology strategy in constraining sediment provenance patterns.

  10. Seroprevalence of pestivirus in four species of alpine wild ungulates in the High Valley of Susa, Italy.

    Science.gov (United States)

    Olde Riekerink, R G M; Dominici, A; Barkema, H W; de Smit, A J

    2005-07-01

    Wildlife, once infected, can serve as a reservoir of infectious diseases that form a constant threat to domestic livestock. To make control and eradication programs successful in the long-term, presence of pestivirus in wildlife populations should be monitored. The goal of this study was to investigate seroprevalence of pestivirus in four alpine wild ungulates in the High Valley of Susa, north-west Italy. Species studied were: red deer (Cervus elaphus), roe deer (Capreolus capreolus), wild boar (Sus scrofa) and chamois (Rupicapra rupicapra). A further goal was using virus neutralisation tests (VNT) for four strains of pestivirus in chamois and wild boar. Three hundred and seventy-five serum samples collected during the hunting season of 1999 were tested for pestivirus specific antibodies. Positive sera of chamois and wild boar were subsequently tested in a VNT with four major subtypes of pestivirus, and virus isolation was performed. No antibodies were found in the 73 samples of roe deer, while 7 (12.5%), 8 (5.9%) and 28 (25.5%) of 56, 136 and 110 samples of wild boar, red deer and chamois were ELISA-positive, respectively. Different ranges of titers were found in the VNT and no pestivirus was isolated in the ELISA-positive wild boar and chamois samples. Several possibilities, which might explain the high seroprevalence in chamois are discussed. Pestivirus antibodies were found in three out of four large alpine ungulates in the High Valley of Susa. Seroprevalence was particularly high in chamois. Further investigation is needed to characterise the pestiviruses that circulate in these animals.

  11. Vector Contact Rates on Eastern Bluebird Nestlings Do Not Indicate West Nile Virus Transmission in Henrico County, Virginia, USA

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    Kevin A. Caillouët

    2013-11-01

    Full Text Available Sensitive indicators of spatial and temporal variation in vector-host contact rates are critical to understanding the transmission and eventual prevention of arboviruses such as West Nile virus (WNV. Monitoring vector contact rates on particularly susceptible and perhaps more exposed avian nestlings may provide an advanced indication of local WNV amplification. To test this hypothesis we monitored WNV infection and vector contact rates among nestlings occupying nest boxes (primarily Eastern bluebirds; Sialia sialis, Turdidae across Henrico County, Virginia, USA, from May to August 2012. Observed host-seeking rates were temporally variable and associated with absolute vector and host abundances. Despite substantial effort to monitor WNV among nestlings and mosquitoes, we did not detect the presence of WNV in these populations. Generally low vector-nestling host contact rates combined with the negative WNV infection data suggest that monitoring transmission parameters among nestling Eastern bluebirds in Henrico County, Virginia, USA may not be a sensitive indicator of WNV activity.

  12. Antibody responses in humans infected with newly emerging strains of West Nile Virus in Europe.

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    Stefan Chabierski

    Full Text Available Infection with West Nile Virus (WNV affects an increasing number of countries worldwide. Although most human infections result in no or mild flu-like symptoms, the elderly and those with a weakened immune system are at higher risk for developing severe neurological disease. Since its introduction into North America in 1999, WNV has spread across the continental United States and caused annual outbreaks with a total of 36,000 documented clinical cases and ∼1,500 deaths. In recent years, outbreaks of neuroinvasive disease also have been reported in Europe. The WNV strains isolated during these outbreaks differ from those in North America, as sequencing has revealed that distinct phylogenetic lineages of WNV concurrently circulate in Europe, which has potential implications for the development of vaccines, therapeutics, and diagnostic tests. Here, we studied the human antibody response to European WNV strains responsible for outbreaks in Italy and Greece in 2010, caused by lineage 1 and 2 strains, respectively. The WNV structural proteins were expressed as a series of overlapping fragments fused to a carrier-protein, and binding of IgG in sera from infected persons was analyzed. The results demonstrate that, although the humoral immune response to WNV in humans is heterogeneous, several dominant peptides are recognized.

  13. Temperature, viral genetics, and the transmission of West Nile virus by Culex pipiens mosquitoes.

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    A Marm Kilpatrick

    2008-06-01

    Full Text Available The distribution and intensity of transmission of vector-borne pathogens can be strongly influenced by the competence of vectors. Vector competence, in turn, can be influenced by temperature and viral genetics. West Nile virus (WNV was introduced into the United States of America in 1999 and subsequently spread throughout much of the Americas. Previously, we have shown that a novel genotype of WNV, WN02, first detected in 2001, spread across the US and was more efficient than the introduced genotype, NY99, at infecting, disseminating, and being transmitted by Culex mosquitoes. In the current study, we determined the relationship between temperature and time since feeding on the probability of transmitting each genotype of WNV. We found that the advantage of the WN02 genotype increases with the product of time and temperature. Thus, warmer temperatures would have facilitated the invasion of the WN02 genotype. In addition, we found that transmission of WNV accelerated sharply with increasing temperature, T, (best fit by a function of T(4 showing that traditional degree-day models underestimate the impact of temperature on WNV transmission. This laboratory study suggests that both viral evolution and temperature help shape the distribution and intensity of transmission of WNV, and provides a model for predicting the impact of temperature and global warming on WNV transmission.

  14. Climate change projections of West Nile virus infections in Europe: implications for blood safety practices.

    Science.gov (United States)

    Semenza, Jan C; Tran, Annelise; Espinosa, Laura; Sudre, Bertrand; Domanovic, Dragoslav; Paz, Shlomit

    2016-03-08

    West Nile virus (WNV) is transmitted by mosquitoes in both urban as well as in rural environments and can be pathogenic in birds, horses and humans. Extrinsic factors such as temperature and land use are determinants of WNV outbreaks in Europe, along with intrinsic factors of the vector and virus. With a multivariate model for WNV transmission we computed the probability of WNV infection in 2014, with July 2014 temperature anomalies. We applied the July temperature anomalies under the balanced A1B climate change scenario (mix of all energy sources, fossil and non-fossil) for 2025 and 2050 to model and project the risk of WNV infection in the future. Since asymptomatic infections are common in humans (which can result in the contamination of the donated blood) we estimated the predictive prevalence of WNV infections in the blood donor population. External validation of the probability model with 2014 cases indicated good prediction, based on an Area Under Curve (AUC) of 0.871 (SD = 0.032), on the Receiver Operating Characteristic Curve (ROC). The climate change projections for 2025 reveal a higher probability of WNV infection particularly at the edges of the current transmission areas (for example in Eastern Croatia, Northeastern and Northwestern Turkey) and an even further expansion in 2050. The prevalence of infection in (blood donor) populations in the outbreak-affected districts is expected to expand in the future. Predictive modelling of environmental and climatic drivers of WNV can be a valuable tool for public health practice. It can help delineate districts at risk for future transmission. These areas can be subjected to integrated disease and vector surveillance, outreach to the public and health care providers, implementation of personal protective measures, screening of blood donors, and vector abatement activities.

  15. 2014: A Record-Breaking Year for West Nile Virus Positive Mosquito Pools in Harris County and the City of Houston, Texas.

    Science.gov (United States)

    Randle, Yvonne H; Freeman, Cheryl Battle; Jackson, Monique; Reyna, Martin; Debboun, Mustapha

    2016-01-01

    In the 14 years since the emergence of West Nile virus (WNV) in Harris County and the city of Houston, Texas, the number of mosquitoes infected with the virus has fluctuated with several high and low count years. During this 14-year period, mosquito surveillance operational areas in Harris County were expanded from 248 to 268 and the distribution of the virus activity in mosquitoes varied from year to year. Operational areas with WNV infected mosquitoes increased from 137 in 2002 to 197 in 2006, decreased to 71 areas in 2007, and to an all-time low of 18 in 2008. The number increased to 78 areas in 2009, 96 in 2010, 133 in 2011, and 177 in 2012, but fell to 73 in 2013. However, 234 areas were confirmed in 2014, and only 138 in 2015. The WNV transmission was high in 2002 with 227 WNV positive mosquito pools. The number of positive mosquitoes remained elevated for a number of years and then declined from 2007 to 2010. Three record high years for WNV activity were: 2005, 2006, and 2011 with 698, 838, and 605 confirmed positive mosquito pools, respectively. Viral activity declined in 2012, followed by a marked decline in 2013 with only 147 WNV positive mosquito pools. In 2014, a record-breaking number of 1,286 WNV positive mosquito pools were confirmed in Harris County and the city of Houston, the most ever in a single season, while 406 were confirmed in 2015.

  16. Transfusion transmittable infections - Seroprevalence among blood donors in a tertiary care hospital of Delhi

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    Sangeeta Pathak

    2013-01-01

    Full Text Available Context: Transfusion transmittable infections (TTI continue to be a major threat to safe transfusion practices. Blood is one of the major sources of transmission of infectious diseases viz. human immunodeficiency virus (HIV, hepatitis B virus (HBV, hepatitis C virus (HCV, syphilis, malaria, and many other infections in India. Screening assays for the infectious diseases with excellent sensitivity and specificity helps to enhance the safety of the blood transfusions reducing the diagnostic window period as much as possible. Aims: The present study was designed to determine the seroprevalence of TTIs viz., HIV, HCV, and HBV, among the blood donors in Max Super Specialty Hospital, New Delhi, India based on dual testing strategy using high sensitive screening assays such as enhanced chemiluminescence assay and nucleic acid testing (NAT. Materials and Methods: A total of 41207 blood units collected from the donors (both voluntary and replacement donors were screened for the TTI s, viz., anti HIV 1 and 2 antibody, anti HCV antibody, anti HBcore antibody, and HBsAg by enhanced chemiluminescence assay on VITROS ® ECiQ immunodiagnostics system. NAT was performed using Roche Cobas ® TaqScreen MPX assay, which can detect simultaneously HIV 1 (groups M and O, HIV-2, HCV, and HBV on Roche Cobas ® s201 system. Results: The seroprevalence of HIV, HBsAg, anti HBcore antibody, and HCV based on enhanced chemiluminescence assay was found to be 0.25, 0.2, 7.06, and 0.7%, respectively. A total number of 6587 samples from July 2010 to December 2010 were tested on NAT, of which 3 samples were reactive for HBV in NAT; this was missed by enhanced chemiluminescence assay. Conclusions: Based on the seroprevalence study of infectious diseases viz., HIV, HBV, and HCV, we conclude that screening of blood and blood components by dual testing strategy using high sensitivity serological assay like enhanced chemiluminescence technology and NAT helps in detecting the

  17. Epidemiology of West Nile in Europe and in the Mediterranean Basin

    OpenAIRE

    Calistri, Paolo; Giovannini, Armando; Hubalek, Zdenek; Ionescu, Aurelia; Monaco, Federica; Savini, Giovanni; Lelli, Rossella

    2010-01-01

    In the last 30 years several cases of West Nile (WN) virus infection were reported in horses and humans in Europe and in the Mediterranean Basin. Most of them were determined by strains of the Lineage 1 included in the European Mediterranean/Kenyan cluster. Strains of this cluster are characterised by a moderate pathogenicity for horses and humans and limited or no pathogenicity for birds. In recent years, however, WN cases determined by strains grouped in the Israeli/American cluster of Line...

  18. Peste des petits ruminants outbreaks in White Nile State, Sudan

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    Osama M. Ishag

    2015-08-01

    Full Text Available Eight outbreaks of peste des petits ruminants in sheep and goats were reported in White Nile State, Sudan, between 2008 and 2009. A mortality rate of 4.2% was reported across the different outbreaks. Clinically the disease was characterised by high fever, ocular and nasal discharge, pneumonia, ulceration of the mucous membranes, diarrhoea and death. The postmortem findings included necrotic lesions in the mouth and gastrointestinal tract, and swollen, oedematous lymph nodes associated with the lungs and intestine. Of the 209 serum samples tested by competitive enzyme-linked immunosorbent assay, 113 (54% were found positive. Peste des petits ruminants virus was confirmed in tissues, nasal swabs and blood samples by immunocapture enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction and isolation of the virus in culture of lamb testicle cells.

  19. Association between seroprevalence of measles and various social determinants in the year following a measles outbreak in Turkey.

    Science.gov (United States)

    Emek, M; Islek, D; Atasoylu, G; Ozbek, O A; Ceylan, A; Acikgoz, A; Tay, Z; Demiral, Y; Oktem, M A; Unal, B

    2017-06-01

    Despite an ongoing measles elimination programme, a measles outbreak occurred in 2013 in Turkey. Population-based seroprevalence studies are needed to determine seronegativity and explore the reasons for this outbreak. This study aimed to explore the seroprevalence of measles and its association with various social determinants in a provincial population in Turkey in the year following a measles outbreak. Cross-sectional study. This study was conducted in Manisa Province in 2014 in a sample of 1740 people aged >2 years. The dependent variable was the seroprevalence of measles. Independent variables were sex, age, migration, household size, household density, income, education level, existence of chronic disease and occupational class. Blood samples were collected from participants at family health centres. The presence of specific measles antibodies in serum samples was determined using an anti-measles virus IgG enzyme-linked immunosorbent assay test. Chi-squared test and logistic regression analysis were performed. Overall, data from 1250 people were analysed. The seroprevalence of measles in the whole study population was 82.2% (95% confidence interval 80.0-84.2). Seroprevalence was 55.4% among subjects aged 2-9 years, 48.7% among subjects aged 10-19 years, 74.1% among subjects aged 20-29 years and 93.6% among subjects aged 30-39 years (P 40 years was >95%. The lowest seroprevalence was found in primary school children (40.2%), followed by those below the age for primary education (69.8%) and secondary school graduates (75.1%). The prevalence of measles seronegativity was not associated with any of the social determinants when adjusted for age. The seroprevalence of measles was lower than expected in the study population and was particularly low in subjects aged measles elimination targets, suggesting that it may be necessary to re-evaluate the need for an extra dose of measles vaccine. Copyright © 2017 The Royal Society for Public Health. Published by Elsevier

  20. Seroprevalences to viral pathogens in free-ranging and captive cheetahs (Acinonyx jubatus) on Namibian farmland

    OpenAIRE

    Thalwitzer, S; Wachter, B; Robert, N; Wibbelt, G; Müller, T; Lonzer, J; Meli, M L; Bay, G; Hofer, H; Lutz, H

    2010-01-01

    Cheetah populations are diminishing rapidly in their natural habitat. One reason for their decline is thought to be a high susceptibility to (infectious) diseases because cheetahs in zoos suffer from high disease-induced mortality. Data on the health status of free-ranging cheetahs are scarce, and little is known about their exposure and susceptibility to infectious diseases. We determined seroprevalences to nine key viruses (feline herpesvirus 1, feline calicivirus, feline parvovirus, feline...

  1. Epidemiology of hepatitis E virus in China: results from the Third National Viral Hepatitis Prevalence Survey, 2005-2006.

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    Zhiyuan Jia

    Full Text Available In China, hepatitis E virus (HEV is prevalent and causes disease, but its epidemiological profile is not well understood. We used a commercial enzyme-linked immunosorbent assay to detect total antibodies to hepatitis E virus in 15,862 serum samples collected during the Third National Viral Hepatitis Prevalence Survey. The results were analyzed to calculate estimates of HEV seroprevalence and to examine the effects of some putative risk factors. The seroprevalence of HEV in the general Chinese population during the period from 2005 through 2006 was 23.46% (95% confidence interval [CI], 18.41%-28.50%. The farming population, the age group of 15-60 year olds, and those living in the Midwest or Mideast region and in Xinjiang province had the highest seroprevalence estimates. The prevalence of HEV is high in China. The seroprevalence rate of HEV shows an unbalanced distribution among areas with different geographic location and economic development levels. The characteristics of the distribution associated may be due to the route of HEV transmission (via contaminated water or animal reservoirs. Within the same region, the seroprevalence of HEV is generally increased with age.

  2. SEROPREVALENCE OF BRUCELLOSIS IN HORSES IN AND AROUND FAISALABAD

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    F. WADOOD, M. AHMAD, A. KHAN1, S. T. GUL1 AND N. REHMAN

    2009-10-01

    Full Text Available Rose Bengal Plate test (RBPT and Serum Agglutination test (SAT were used to monitor the seroprevalence of brucellosis in horses in and around Faisalabad, Pakistan. Sera were screened by RBPT and positive or doubtful sera were further processed by SAT for confirmation. The overall seroprevalence of brucellosis in horses was 20.7 and 17.7% by RBPT and SAT, respectively. Source wise seroprevalence of brucellosis was 19.8, 25.5, 2.9 and 0% in horses of Remount Area Faisalabad, Remount Area Toba Tek Singh, private and Livestock Management Department University of Agriculture Faisalabad, respectively. Sex wise seroprevalence in horses was 9.67 and 17.7% in male and female, respectively. In relation to age, seroprevalence was 12.9, 16.5, 14.8 and 20.6%, in horses of 1-5, 6-10, 11-15 and above 15 years of age, respectively. Highest seroprevalence was recorded in horses of above 15 years of age. Depending upon the body condition, the seroprevalence was 9.7, 13, and 20% in poor fair, and good body conditioned horses, respectively. Seroprevalence of brucellosis on the basis of parity was 19.2, 20.9, 18.7, 16.6, and 21.1% in 0, 1, 2, 3 and above 3 foaling females, respectively. Prevalence of brucellosis in different breeds of horses was 22.4, 17.1, 25.7 and 0.0% in Desi, Thoroughbred, Crossbred and Arabian horses, respectively. However, statistically, in relation to various factors like source, sex, body condition, parity and breed of horses, a non significant difference was observed among various groups. Statistically a significant difference (P<0.001 in seroprevalence was observed with respect to age, only.

  3. Seroprevalence survey of avian influenza A (H5) in wild migratory birds in Yunnan Province, Southwestern China.

    Science.gov (United States)

    Chang, Hua; Dai, Feiyan; Liu, Zili; Yuan, Feizhou; Zhao, Siyue; Xiang, Xun; Zou, Fengcai; Zeng, Bangquan; Fan, Yating; Duan, Gang

    2014-02-03

    Highly pathogenic avian influenza virus (HPAIV) is a highly contagious disease which is a zoonotic pathogen of significant economic and public health concern. The outbreaks caused by HPAIV H5N1 of Asian origin have caused animal and human disease and mortality in several countries of Southeast Asia, such as Bangladesh, Cambodia, China, India, Indonesia, Laos, Myanmar, Thailand and Viet Nam. For the first time since 1961, this HPAIV has also caused extensive mortality in wild birds and has sparked debate of the role wild birds have played in the spread of this virus. Other than confirmed mortality events, little is known of this virus in wild birds. There is no report on the seroprevalence of avian influenza H5 infection in wild migratory birds in Yunnan Province. In this study we examined live wild birds in Yunnan Province for H5 specific antibody to better understand the occurrence of this disease in free living birds. Sera from 440 wild birds were collected from in Kunming and Northern Ailaoshan of Yunnan Province, Southwestern China, and assayed for H5 antibodies using the hemagglutination inhibition (HI) assays. The investigation revealed that the seroprevalence of avian influenza H5 was as following: Ciconiiformes 2.6%, Strigiformes 13.04%, Passeriformes 20%, Cuculiformes 21.74%, Gruiformes 0%, Columbiformes 0%, Charadriiformes 0% and Coraciiformes 0%. Statistical analyses showed that there was a significant difference of prevalence between the orders (P avian influenza H5 antibodies were detected in 23 of 440 (5.23%) sera. Mean HI titer 23 positive sera against H5 were 5.4 log₂. The results of the present survey indicated that the proportion of wild birds had previously infected AIV H5 at other times of the year. To our knowledge, this is the first seroprevalence report of avian influenza H5 infection in wild migratory birds in China' s southwestern Yunnan Province. The results of the present survey have significant public health concerns.

  4. Identification of diagnostic peptide regions that distinguish Zika virus from related mosquito-borne Flaviviruses.

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    Alexandra J Lee

    Full Text Available Zika virus (ZIKV is a member of the Flavivirus genus of positive-sense single-stranded RNA viruses, which includes Dengue, West Nile, Yellow Fever, and other mosquito-borne arboviruses. Infection by ZIKV can be difficult to distinguish from infection by other mosquito-borne Flaviviruses due to high sequence similarity, serum antibody cross-reactivity, and virus co-circulation in endemic areas. Indeed, existing serological methods are not able to consistently differentiate ZIKV from other Flaviviruses, which makes it extremely difficult to accurately calculate the incidence rate of Zika-associated Guillain-Barre in adults, microcephaly in newborns, or asymptomatic infections within a geographical area. In order to identify Zika-specific peptide regions that could be used as serology reagents, we have applied comparative genomics and protein structure analyses to identify amino acid residues that distinguish each of 10 Flavivirus species and subtypes from each other by calculating the specificity, sensitivity, and surface exposure of each residue in relevant target proteins. For ZIKV we identified 104 and 116 15-mer peptides in the E glycoprotein and NS1 non-structural protein, respectively, that contain multiple diagnostic sites and are located in surface-exposed regions in the tertiary protein structure. These sensitive, specific, and surface-exposed peptide regions should serve as useful reagents for seroprevalence studies to better distinguish between prior infections with any of these mosquito-borne Flaviviruses. The development of better detection methods and diagnostic tools will enable clinicians and public health workers to more accurately estimate the true incidence rate of asymptomatic infections, neurological syndromes, and birth defects associated with ZIKV infection.

  5. West Nile virus infection rates in Culex nigripalpus (Diptera: Culicidae) do not reflect transmission rates in Florida.

    Science.gov (United States)

    Rutledge, C Roxanne; Day, Jonathan F; Lord, Cynthia C; Stark, Lillian M; Tabachnick, Walter J

    2003-05-01

    We describe the first documented field transmission of West Nile (WN) virus by a North American mosquito. WN was first detected in northern Florida in 2001. An intensive mosquito trapping and surveillance program was conducted in this region for four nights to assess mosquito transmission of WN. Four mosquito traps, each with a single sentinel chicken, were placed at five different locations on each of four nights. A total of 11,948 mosquitoes was collected, and 14 mosquito pools were found to contain WN, giving a minimum infection rate between 1.08 and 7.54 per 1,000. Only one of the 80 sentinel chickens seroconverted to WN, demonstrating a single mosquito transmission event during the study and a mosquito transmission rate of between 0.8 and 1 per 1,000. Culex nigripalpus Theobald was responsible for WN transmission to the sentinel chicken, although both Cx. nigripalpus and Culex quinquefasciatus Say were found infected with WN. Mosquito transmission rates are reported in this study for the first time for a WN outbreak. This information is essential to determine risk of human and animal infection.

  6. Neurotropism of Saffold virus in a mouse model

    NARCIS (Netherlands)

    Lardinois, Cécile; Sorgeloos, Frédéric; Jacobs, Sophie; van Kuppeveld, Frank J M; Kaspers, Bernd; Michiels, Thomas

    2016-01-01

    Saffold virus (SAFV) is a highly seroprevalent human Cardiovirus discovered recently. No clear association between SAFV infection and human disease has been established. Rare infection cases, however, correlated with neurological symptoms. To gain insight into the pathogenesis potential of the

  7. Hepatitis e virus: Western Cape, South Africa

    NARCIS (Netherlands)

    R.G. Madden (Richie); Wallace, S. (Sebastian); M. Sonderup; Korsman, S. (Stephen); Chivese, T. (Tawanda); Gavine, B. (Bronwyn); Edem, A. (Aniefiok); Govender, R. (Roxy); English, N. (Nathan); Kaiyamo, C. (Christy); Lutchman, O. (Odelia); A.A. Eijck (Annemiek); S.D. Pas (Suzan); Webb, G.W. (Glynn W); Palmer, J. (Joanne); Goddard, E. (Elizabeth); Wasserman, S. (Sean); H.R. Dalton (Harry); C.W. Spearman

    2016-01-01

    textabstractAIM To conduct a prospective assessment of anti-hepatitis E virus (HEV) IgG seroprevalence in the Western Cape Province of South Africa in conjunction with evaluating risk factors for exposure. METHODS Consenting participants attending clinics and wards of Groote Schuur, Red Cross

  8. Seroprevalence and correlates of herpes simplex virus type 2 infection among young adults in Arkhangelsk, Northwest Russia: a population-based cross-sectional study

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    Tatiana Balaeva

    2016-10-01

    Full Text Available Abstract Background Herpes simplex virus type 2 (HSV-2 infection is the most common cause of genital ulcer disease (GUD worldwide. Mother to child transmission causes high morbidity and mortality among infants. Russia is on the brink of a generalized HIV-epidemic, but Arkhangelsk is still a low-prevalence area. HSV-2 infection is associated with a three-fold increased risk of HIV-infection. The evidence on the seroprevalence of HSV-2 in Russia is limited. The aim of this study was to assess HSV-2 seroprevalence and correlates among young adults in the city of Arkhangelsk. Methods 1243 adults aged 18-39 years participated in a cross-sectional population-based study, recruited by a public opinion agency applying a quota sampling method to achieve a data set with similar age- and sex-distribution as the population in Arkhangelsk. All participants completed a standardized, self-administrated questionnaire and were tested for HSV-2. Associations between HSV-2 seropositivity and selected sociodemographic and behavioral factors, and self-reported history of sexually transmitted infections (STIs were studied by multivariable logistic regression. Results HSV-2 seroprevalence was 18.8 %: 12.2 % (95 % confidence interval, CI 9.7-15.2 among men and 24.0 % (95 % CI 20.1-27.3 among women. Among men, HSV-2 positivity was associated with being divorced/widowed (OR = 2.85, 95 % CI 1.06-7.70, cohabitation (OR = 2.45, 95 % CI 1.07-5.62, and a history of STIs (OR = 2.11, 95 % CI 1.14-3.91. In women, HSV-2 positivity was associated with high income (OR = 3.11, 95 % CI 1.45-6.71 and having a lifetime number of sexual partners between 2 and 5 (OR = 2.72, 95 % CI 1.14-6.51, whereas sexual debut at age 18 years or older was inversely associated with the outcome (OR = 0.47, 95 % CI 0.31-0.72. In both sexes, increasing age was the strongest correlate of HSV-2 seropositivity in multivariable analyses. Conclusion The HSV-2 seroprevalence

  9. Entomologic investigations during an outbreak of West Nile virus disease in Maricopa County, Arizona, 2010.

    Science.gov (United States)

    Godsey, Marvin S; Burkhalter, Kristen; Young, Ginger; Delorey, Mark; Smith, Kirk; Townsend, John; Levy, Craig; Mutebi, John-Paul

    2012-12-01

    Entomologic investigations were conducted during an intense outbreak of West Nile virus (WNV) disease in Maricopa County, Arizona during July 31-August 9, 2010. The investigations compared the East Valley outbreak area, and a demographically similar control area in northwestern metropolitan Phoenix where no human cases were reported. Five mosquito species were identified in each area, and species composition was similar in both areas. Significantly more Culex quinquefasciatus females were collected by gravid traps at Outbreak sites (22.2 per trap night) than at control sites (8.9 per trap night), indicating higher Cx. quinquefasciatus abundance in the outbreak area. Twenty-eight WNV TaqMan reverse transcription-polymerase chain reaction-positive mosquito pools were identified, including 24 of Cx. quinquefasciatus, 3 of Psorophora columbiae, and 1 of Culex sp. However, Cx. quinquefasciatus WNV infection rates did not differ between outbreak and control sites. At outbreak sites, 30 of 39 engorged Cx. quinquefasciatus had fed on birds, 8 of 39 on humans, and 1 of 39 on a lizard. At control sites, 20 of 20 identified blood meals were from birds. Data suggest that Cx. quinquefasciatus was the primary enzootic and epidemic vector of this outbreak. The most important parameters in the outbreak were vector abundance and blood meal analysis, which suggested more frequent contact between Cx. quinquefasciatus and human hosts in the outbreak area compared with the control area.

  10. Blood group A and Rh(D)-negativity are associated with symptomatic West Nile virus infection

    Science.gov (United States)

    Kaidarova, Zhanna; Bravo, Marjorie D.; Kamel, Hany T.; Custer, Brian S; Busch, Michael P.; Lanteri, Marion C.

    2016-01-01

    Background West Nile virus (WNV) infection is mostly asymptomatic but 20% of subjects report WNV fever and 1% of patients experience neurological diseases with higher rates in elderly and immunosuppressed persons. With no treatment and no vaccine to prevent the development of symptomatic infections, it is essential to understand prognostic factors influencing symptomatic disease outcome. Host genetic background has been linked to the development of WNV neuroinvasive disease. The present study investigates the association between the ABO and Rh(D) blood group status and WNV disease outcome. Study Design and Methods The distribution of blood groups was investigated within a cohort of 374 WNV+ blood donors including 244 asymptomatic (AS) and 130 symptomatic (S) WNV+ blood donors. Logistic regression analyses were used to examine associations between A, B, O and Rh(D) blood groups and WNV clinical disease outcome. Results Symptomatic WNV+ donors exhibited increased frequencies of blood group A (S 47.6% AS 36.8%, P=0.04, OR [95%CI] 1.56 [1.01–2.40]) and Rh(D)-negative individuals (S 21.5% AS 13.1%, P=0.03, OR [95%CI] 1.82 [1.04–3.18]). Conclusion The findings suggest a genetic susceptibility placing blood group A and Rh(D)-negative individuals at risk for the development of symptomatic disease outcome after WNV infection. PMID:27189860

  11. Seroprevalence and risk factors of Kaposi's sarcoma-associated herpesvirus infection among the general Uygur population from south and north region of Xinjiang, China

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    Wang Hui

    2011-12-01

    Full Text Available Abstract Background Kaposi sarcoma (KS is a complex multifocal neoplasm and is the major cause of death for about 50% of acquired immunodeficiency syndrome (AIDS patients. Kaposi's sarcoma-associated herpesvirus (KSHV is an oncogenic virus with a causal role in the development of all types of KS. KS is prevalent among the Uygur people in Xinjiang, especially in south area. Here we carried out a cross-sectional study among 1534 general Uygur individuals from south and north region of Xinjiang to assess the seroprevalence of KSHV and to identify the potential correlation between KSHV seroprevalence and KS incidence. Results Seroprevalence of KSHV in South and North Xinjiang was 23.1% and 25.9%, respectively. Older age was independently associated with higher KSHV seroprevalence. In subjects from South Xinjiang, lower educational level and reported drinking were each independently associated with higher KSHV seroprevalence. Furthermore, the antibody titer was significantly lower in both south and north KSHV seropositive individuals compared with KS patients, as analyzed by gradient dilution (P Conclusion KSHV is highly prevalent in the general Uygur population in both South and North Xinjiang. Interestingly, the infection rate of KSHV in these two geographical areas did not correlate well with KS incidence. Perhaps unknown factors exist that promote the progression of KSHV infection to KS development in the local minority groups.

  12. EPIDEMIOLOGY OF SCHMALLENBERG VIRUS IN EUROPEAN BISON ( BISON BONASUS) IN POLAND.

    Science.gov (United States)

    Kęsik-Maliszewska, Julia; Krzysiak, Michał K; Grochowska, Maria; Lechowski, Lech; Chase, Christopher; Larska, Magdalena

    2018-04-01

    Schmallenberg virus (SBV), an emerging arbovirus in Europe, is an important pathogen in domestic ruminants; however, its impact on free-ranging wild ruminants is not well studied. Three hundred and forty-seven serum samples collected between 2011 and 2016 from 302 European bison ( Bison bonasus) from 12 different sites in Poland were tested for the presence of SBV antibodies. In addition, 86 sera were collected between 2013 and 2016 from three species of cervids for testing for SBV antibodies. After the first detection of the virus in Poland in October 2012, the proportion of SBV-seropositive European bison reached 81% (95% confidence interval [CI]: 77.1-85.8%), whereas in cervids seroprevalence was 34% (95% CI: 23.5-43.9%). There was an increase in seroprevalence in European bison from 2012 to 2014. Biting midges ( Culicoides spp.), the primary vectors of SBV, were monitored entomologically for the identification of the biting midge populations and virologically for SBV infections in the Białowieża Forest region, which contains the world's largest European bison population. We detected SBV by PCR in 3% of Culicoides pools from 2015. In addition, seven fetal brain samples from European bison or cervids were tested and were negative for SBV RNA. Our results indicate a high seroprevalence with reduced transmission of SBV in subsequent years in the European bison populations and lower seroprevalence in cervids.

  13. Serosurveillance of infectious agents in equines of the Central Valley of Costa Rica.

    Science.gov (United States)

    Jiménez, D; Romero-Zuñiga, J J; Dolz, G

    2014-01-01

    Blood samples from 181 equines from the Central Valley of Costa Rica were collected in the year 2012 to determine the presence of antibodies against selected infectious agents in horses and to determine the risk factors associated with these agents. The presence of antibodies against Equine Infectious Anemia Virus (EIAV), Equine Herpes Virus 1 and 4 (EHV-1 and EHV-4), West Nile Virus (WNV), Influenza A Virus (IAV), Equine Viral Arteritis Virus (EVAV), Babesia caballi, Theileria equi, Neospora caninum and Chlamydia abortus was determined using commercial assays, and risk factors associated with seropositivity to the different infectious agents was established. The most seroprevalent agent detected was EHV-4 (96.7%), followed by WNV (44.2%), and IAV (41.8%). Horses >3 years, used for work or sports, and with access to pastures, had significantly increased probability to be seropositive to WNV, whereas horses used for breeding and recreational purposes, being stabled, and without access to pastures, had significantly greater probability to be seropositive to IAV. Seroprevalence to B. caballi (19.9%) was lower than to T. equi (38.1%). For B. caballi, access to pastures was determined as a risk factor, whereas being older than 3 years was established as a risk factor for T. equi. Low seroprevalences were determined for EHV-1 (5.0%), EVAV (5.0%), C. abortus (4.8%), and N. caninum (4.4%). Mares having history of abortion were more likely to be seropositive to EHV-1, whereas horses >3 years, used for work and sports, and mares having multiple parturitions, were more likely to be seropositive to N. caninum. None of the horses were seropositive to EIAV. Earlier, only diseases caused by EIAV, WNV and piroplasmosis were reported in Costa Rica. The present study however, determined the presence of carriers for EHV-1, EHV-4, and EIAV.

  14. Serosurveillance of infectious agents in equines of the Central Valley of Costa Rica

    Directory of Open Access Journals (Sweden)

    D. Jiménez

    2014-11-01

    Full Text Available Blood samples from 181 equines from the Central Valley of Costa Rica were collected in the year 2012 to determine the presence of antibodies against selected infectious agents in horses and to determine the risk factors associated with these agents. The presence of antibodies against Equine Infectious Anemia Virus (EIAV, Equine Herpes Virus 1 and 4 (EHV-1 and EHV-4, West Nile Virus (WNV, Influenza A Virus (IAV, Equine Viral Arteritis Virus (EVAV, Babesia caballi, Theileria equi, Neospora caninum and Chlamydia abortus was determined using commercial assays, and risk factors associated with seropositivity to the different infectious agents was established. The most seroprevalent agent detected was EHV-4 (96.7%, followed by WNV (44.2%, and IAV (41.8%. Horses >3 years, used for work or sports, and with access to pastures, had significantly increased probability to be seropositive to WNV, whereas horses used for breeding and recreational purposes, being stabled, and without access to pastures, had significantly greater probability to be seropositive to IAV. Seroprevalence to B. caballi (19.9% was lower than to T. equi (38.1%. For B. caballi, access to pastures was determined as a risk factor, whereas being older than 3 years was established as a risk factor for T. equi. Low seroprevalences were determined for EHV-1 (5.0%, EVAV (5.0%, C. abortus (4.8%, and N. caninum (4.4%. Mares having history of abortion were more likely to be seropositive to EHV-1, whereas horses >3 years, used for work and sports, and mares having multiple parturitions, were more likely to be seropositive to N. caninum. None of the horses were seropositive to EIAV. Earlier, only diseases caused by EIAV, WNV and piroplasmosis were reported in Costa Rica. The present study however, determined the presence of carriers for EHV-1, EHV-4, and EIAV.

  15. Temporal trends of influenza A (H1N1 virus seroprevalence following 2009 pandemic wave in Guangdong, China: three cross-sectional serology surveys.

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    Fen Yang

    Full Text Available BACKGROUND: To evaluate the temporal trends of seroprevalence to pH1N1 among the Guangdong population following 2009 H1N1 pandemic wave, we conducted three cross-sectional serology surveys in 2010. METHODOLOGY/PRINCIPAL FINDINGS: Three surveys were carried out consecutively in 2010 from January 8 to January 24, from March 15 to April 10 and from August 23 to September 4. Sample populations comprising of 4725, 4727, and 4721 subjects respectively were randomly selected for study in these three surveys. The level of antibodies against pH1N1 was evaluated by hemagglutination inhibition assay. In survey 1, the seroprevalence of pH1N1 among all the subjects is 25.1%, declining to 18.4% in survey 2 and increasing to 21.4% in survey 3. Among vaccinated subjects, the seroprevalence was 49.0%, 53.0%, and 49.4% in the three consecutive surveys, showing no significant differences. In contrast, among non-vaccinated subjects, the seroprevalence declined significantly from 22.8% (survey 1 to 14.3% (survey 2 and subsequently increased to 18.1% (survey 3. The multivariate logistic regression analysis revealed that seroprevalence to pH1N1 in non-vaccinated individuals correlated with the investigated order of the surveys, age, and region (all P<0.05. However, it was not correlated with gender (P = 0.650, seasonal influenza vaccination history (P = 0.402 and symptoms (P = 0.074. CONCLUSIONS/SIGNIFICANCE: In Guangdong, the seroprevalance to pH1N1 decreased initially and then rebounded modestly during the first 9 months following the 2009 pandemic wave. Our results suggest that the prevalence of pH1N1 is still correlated with age and population density during the post-pandemic period. An early end to the free pH1N1 vaccination program might be another important reason for the slight rebound in seroprevalance. Our study findings can help the Guangdong authorities to make evidence-based decisions about a long-term vaccination strategy and boost immunity in specific

  16. Sero-prevalence, risk factors and distribution of sheep and goat pox in Amhara Region, Ethiopia.

    Science.gov (United States)

    Fentie, Tsegaw; Fenta, Nigusie; Leta, Samson; Molla, Wassie; Ayele, Birhanu; Teshome, Yechale; Nigatu, Seleshe; Assefa, Ashenafi

    2017-12-11

    Sheep pox and goat pox are contagious viral diseases of sheep and goats, respectively. The diseases result in substantial economic losses due to decreased milk and meat production, damage to hides and wool, and possible trade restriction. A study was undertaken in Amhara region of Ethiopia. A cross-sectional study design was used to estimate the sero-prevalence and identify associated risk factors, while retrospective study design was used to assess the temporal and spatial distribution of the disease. A total of 672 serum samples were collected from 30 Kebeles and tested using virus neutralization test. From a total of 672 sera tested, 104 (15.5%) were positive for sheep and goat pox virus antibody; from which 56 (17%) were sheep and 48 (14%) were goats. The diseases were prevalent in all study zones, the highest sero-prevalence was observed in South Gondar (20.9%) and the lowest in North Gondar and West Gojjam zones (11.9% each). From the potential risk factors considered (species, sex, age, agro-ecology and location); only sex and age were significantly associated (p pox is one of the most prevalent and widespread diseases of sheep and goats in the study area. Hence, annual mass vaccination program must be implemented for economic and viable control of sheep and goat pox diseases in the Amhara region in particular and at a national level in general.

  17. The White Nile sedimentary system

    Science.gov (United States)

    Garzanti, Eduardo; Andò, Sergio; Padoan, Marta; Resentini, Alberto; Vezzoli, Giovanni; Villa, Igor

    2014-05-01

    The Nile River flows for ~6700 km from south of the Equator to finally reach the Mediterranean Sea at northern subtropical latitudes (Woodward et al. 2007). This is the longest sedimentological laboratory on Earth, a unique setting in which we are investigating changes in sediment composition associated with diverse chemical and physical processes, including weathering and hydraulic sorting. The present study focuses on the southern branch of the Nile across 20° of latitude, from hyperhumid Burundi and Rwanda highlands in central Africa to Khartoum, the capital city of Sudan at the southern edge of the Sahara. Our study of the Kagera basin emphasizes the importance of weathering in soils at the source rather than during stepwise transport, and shows that the transformation of parent rocks into quartzose sand may be completed in one sedimentary cycle (Garzanti et al. 2013a). Micas and heavy minerals, less effectively diluted by recycling than main framework components, offer the best key to identify the original source-rock imprint. The different behaviour of chemical indices such as the CIA (a truer indicator of weathering) and the WIP (markedly affected by quartz dilution) helps us to distinguish strongly weathered first-cycle versus polycyclic quartz sands (Garzanti et al. 2013b). Because sediment is efficiently trapped in East African Rift lakes, the composition of Nile sediments changes repeatedly northwards across Uganda. Downstream of both Lake Kyoga and Lake Albert, quartzose sands are progressively enriched in metamorphiclastic detritus supplied from tributaries draining amphibolite-facies basements. The evolution of White Nile sediments across South Sudan, a scarcely accessible region that suffered decades of civil war, was inferred from the available information (Shukri 1950), integrated by original petrographic, heavy-mineral and geochemical data (Padoan et al. 2011). Mineralogical and isotopic signatures of Bahr-el-Jebel and Sobat sediments, derived

  18. Seroprevalence of toxoplasmosis in sheep in South Africa

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    N. Abu Samraa

    2007-06-01

    Full Text Available Serum samples from 600 sheep were collected from 5 different provinces randomly chosen in South Africa. Two sheep abattoirs (representing formal slaughter of sheep and 1 rural location (representing informal slaughter of sheep per province were also selected randomly. The serum samples were tested for anti-Toxoplasma gondii IgG antibodies using 2 different serological tests : an indirect fluorescent antibody (IFA test and an enzyme-linked immunosorbent assay (ELISA test available as a commercial kit. This study provides the first published data on seroprevalence of toxoplasmosis in sheep in South Africa, although positive titres have been found previously in wild felids, ferrets, chinchillas and a dog. Data on seroprevalence in sheep is considered important because consumption of mutton is universally considered to be a source of zoonotic transfer to humans. Seroprevalence in humans in South Africa was previously found to be 20% and it is postulated that this may be linked to the informal slaughter and consumption of mutton. During this study, the overall national seroprevalence per province in sheep was found to be 5.6 % (IFA and 4.3 % (ELISA, respectively. This is lower than in other countries, possibly because South Africa has an arid climate. Differences in seroprevalence in different areas studied suggested an association with the climate and a significant correlation (P > 0.05 was detected between the prevalence of T. gondii and the minimum average temperature. The seroprevalence was found to be significantly higher (P < 0.01 in sheep originating from commercial farms (7.9 % than in rural sheep in the informal sector (3.4 %. Also, sheep managed extensively had a seroprevalence of 1.8 %, which was significantly lower (P < 0.05 than the seroprevalence in sheep under semi-intensive or intensive management systems (5.3 %. An incidental finding of interest was the considerable movement of sheep to abattoirs and mutton after slaughter. The

  19. The initiation and evolution of the River Nile

    Science.gov (United States)

    Fielding, Laura; Najman, Yani; Millar, Ian; Butterworth, Peter; Garzanti, Eduardo; Vezzoli, Giovanni; Barfod, Dan; Kneller, Ben

    2018-05-01

    The Nile is generally regarded as the longest river in the world. Knowledge of the timing of the Nile's initiation as a major river is important to a number of research questions. For example, the timing of the river's establishment as a catchment of continental proportions can be used to document surface uplift of its Ethiopian upland drainage, with implications for constraining rift tectonics. Furthermore, the time of major freshwater input to the Mediterranean is considered to be an important factor in the development of sapropels. Yet the river's initiation as a major drainage is currently constrained no more precisely than Eocene to Pleistocene. Within the modern Nile catchment, voluminous Cenozoic Continental Flood Basalts (CFBs) are unique to the Ethiopian Highlands; thus first detection of their presence in the Nile delta record indicates establishment of the river's drainage at continental proportions at that time. We present the first detailed multiproxy provenance study of Oligocene-Recent Nile delta cone sediments. We demonstrate the presence of Ethiopian CFB detritus in the Nile delta from the start of our studied record (c. 31 Ma) by (1) documenting the presence of zircons with U-Pb ages unique, within the Nile catchment, to the Ethiopian CFBs and (2) using Sr-Nd data to construct a mixing model which indicates a contribution from the CFBs. We thereby show that the Nile river was established as a river of continental proportions by Oligocene times. We use petrography and heavy mineral data to show that previous petrographic provenance studies which proposed a Pleistocene age for first arrival of Ethiopian CFBs in the Nile delta did not take into account the strong diagenetic influence on the samples. We use a range of techniques to show that sediments were derived from Phanerozoic sedimentary rocks that blanket North Africa, Arabian-Nubian Shield basement terranes, and Ethiopian CFB's. We see no significant input from Archaean cratons supplied

  20. The role of influenza, RSV and other common respiratory viruses in severe acute respiratory infections and influenza-like illness in a population with a high HIV sero-prevalence, South Africa 2012-2015.

    Science.gov (United States)

    Pretorius, Marthi A; Tempia, Stefano; Walaza, Sibongile; Cohen, Adam L; Moyes, Jocelyn; Variava, Ebrahim; Dawood, Halima; Seleka, Mpho; Hellferscee, Orienka; Treurnicht, Florette; Cohen, Cheryl; Venter, Marietjie

    2016-02-01

    Viruses detected in patients with acute respiratory infections may be the cause of illness or asymptomatic shedding. To estimate the attributable fraction (AF) and the detection rate attributable to illness for each of the different respiratory viruses We compared the prevalence of 10 common respiratory viruses (influenza A and B viruses, parainfluenza virus 1-3; respiratory syncytial virus (RSV); adenovirus, rhinovirus, human metapneumovirus (hMPV) and enterovirus) in both HIV positive and negative patients hospitalized with severe acute respiratory illness (SARI), outpatients with influenza-like illness (ILI), and control subjects who did not report any febrile, respiratory or gastrointestinal illness during 2012-2015 in South Africa. We enrolled 1959 SARI, 3784 ILI and 1793 controls with a HIV sero-prevalence of 26%, 30% and 43%, respectively. Influenza virus (AF: 86.3%; 95%CI: 77.7-91.6%), hMPV (AF: 85.6%; 95%CI: 72.0-92.6%), and RSV (AF: 83.7%; 95%CI: 77.5-88.2%) infections were associated with severe disease., while rhinovirus (AF: 46.9%; 95%CI: 37.6-56.5%) and adenovirus (AF: 36.4%; 95%CI: 20.6-49.0%) were only moderately associated. Influenza, RSV and hMPV can be considered pathogens if detected in ILI and SARI while rhinovirus and adenovirus were commonly identified in controls suggesting that they may cause only a proportion of clinical disease observed in positive patients. Nonetheless, they may be important contributors to disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Rapid GIS-based profiling of West Nile virus transmission: defining environmental factors associated with an urbansuburban outbreak in Northeast Ohio, USA

    Directory of Open Access Journals (Sweden)

    A. Desiree LaBeaud

    2008-05-01

    Full Text Available Human West Nile virus (WNV infection was first detected in Cuyahoga county, Ohio, USA, in 2002. During that year’s extensive epidemic/epizootic among non-immune human and bird populations, the county experienced 155 cases of severe human West Nile neurological disease (WNND, incidence = 11.1 cases/100,000, with 11 fatalities. Structured serosurveys indicated that 1.9%, or ~ 26,000 of county residents (population = 1,372,303 were infected that year. In early 2003, in order to better focus monitoring and control efforts, we used a geographical information system (GIS approach and spatial statistical analysis to identify the association of environmental factors and human population structure with the observed local risk for WNV transmission. Within the varied range of urban/suburban/ rural habitats across the 1186 km2 county, exploratory analysis indicated significant clustering of WNND risk in inner-ring suburbs. Subsequent discriminant factor analysis based on inputs of census and land-use/land cover data was found to effectively classify sub-areas of the county having low, medium and high WNV risk. On a 1036 ha quadrat scale of resolution, higher risk of human infection was significantly associated with higher-income areas, increased fractionation of habitat and older housing, while it was negatively associated with areas of agricultural land, wetland or forest. The areal classification of WNV transmission risk has been validated over time through detection of increased local Culex spp. mosquito density (2002-2006, and increased frequency of WNV positive mosquito pools within the medium- and high-risk quadrats. This timely working identification of the transmission scale effectively focused control interventions against newly invasive WNV in a complex North American habitat.

  2. West Nile virus (linie 2) v komárech na jižní Moravě – očekávání prvních autochtonních lidských případů

    Czech Academy of Sciences Publication Activity Database

    Rudolf, Ivo; Blažejová, Hana; Šebesta, Oldřich; Mendel, Jan; Peško, Juraj; Betášová, Lenka; Straková, Petra; Šikutová, Silvie; Hubálek, Zdeněk

    2018-01-01

    Roč. 67, č. 1 (2018), s. 44-46 ISSN 1210-7913 R&D Projects: GA ČR(CZ) GA16-20054S Grant - others:AV ČR + JMK + město Břeclav(CZ) R200931601 Institutional support: RVO:68081766 Keywords : West Nile virus * arboviruses * emerging zoonoses * mosquitoes * Culex pipiens * Culex modestus Subject RIV: EE - Microbiology, Virology OBOR OECD: Virology Impact factor: 0.500, year: 2016

  3. Influence of Bloodmeal Source on Reproductive Output of the Potential West Nile Vector, Culex theileri (Diptera: Culicidae).

    Science.gov (United States)

    Demirci, Berna; Durmaz, Esra; Alten, Bulent

    2014-11-01

    Culex theileri Theobald (Diptera: Culicidae) has a wide Afrotropical, southern Palaearctic, northern Oriental, and European distribution. It is mainly considered as a mammophilic mosquito and also feeds on birds and serves as a vector for various zoonotic diseases including West Nile virus. Despite its broad distribution and evidence indicating that Cx. theileri is a competent vector of human and domestic animal pathogens, basic biological and ecological features of this species have not been well investigated. We evaluated the impact of bloodmeal source (human, chicken, cow, and a double bloodmeal such as human and cow or chicken and cow and mixed bloodmeals [cow, chicken, and human] via artificial feeding) on fecundity, hatching rates, developmental times, and viability from egg to adult for laboratory colonized Cx. theileri. Fecundity in mosquitoes that took a chicken bloodmeal, a double bloodmeal and mixed bloodmeals was significantly higher than in females fed on a single cow or single human blood. This is the first study about the bloodmeal sources effect on laboratory-reared Cx. theileri populations and these findings contribute to our understanding of the impact of bloodmeal source on reproduction in Cx. theileri. As it is known that Cx. theileri is a vector for West Nile virus, the potential impacts of bloodmeal source on virus transmission are discussed. © 2014 Entomological Society of America.

  4. West Nile Review: 15 Years of Human Disease in South Dakota, 2002-2016.

    Science.gov (United States)

    Kightlinger, Lon

    2017-08-01

    During the past 15 years, 2002-2016, West Nile virus (WNV) has emerged in South Dakota resulting in 509 neuroinvasive disease (NID) cases, 745 hospitalizations and 38 deaths. Culex tarsalis is the state's primary mosquito vector. South Dakota's average annual incidence of WNV-NID and death rate are the highest of any state in the U.S. WNV cases have been reported from all counties in the state. All age groups have been infected with cases peaking in the 40-44 year age group, but deaths peaking in cases 70 years and older. Although South Dakota's WNV season lasts six months, May-October, the first week of August has been the peak week of WNV disease onsets. West Nile is now enzootic in South Dakota. Every citizen, local mosquito control programs, medical and public health infrastructures must continue to prevent and respond to annual WNV outbreaks, and prepare for the next arboviral disease to emerge. Copyright© South Dakota State Medical Association.

  5. Rheumatologic manifestations associated with Hepatitis C virus ...

    African Journals Online (AJOL)

    Background: Hepatitis C Virus (HCV) infection is a worldwide burden whose seroprevalence is higher in developing countries with Cameroon being the third most affected country in Africa. HCV both a hepatotropic and lymphotropic infection is responsible for a great number of hepatic and extra hepatic disorders some of ...

  6. Ecology of West Nile Fever across four European countries: Review of weather profiles, vector population dynamics and vector control response

    Science.gov (United States)

    West Nile virus (WNV) represents a serious burden to human and animal health because of its capacity to cause large unforeseen epidemics. Until 2004, only lineage 1 and 3 WNV strains had been found in Europe. Lineage 2 strains were initially isolated in 2004 (Hungary), again in 2008 (Austria), and f...

  7. Spatial and Temporal Epidemiology of Nephropathia Epidemica Incidence and Hantavirus Seroprevalence in Rodent Hosts: Identification of the Main Environmental Factors in Europe.

    Science.gov (United States)

    Monchatre-Leroy, E; Crespin, L; Boué, F; Marianneau, P; Calavas, D; Hénaux, V

    2017-08-01

    In Europe, the increasing number of nephropathia epidemica (NE) infections in humans, caused by Puumala virus carried by bank voles (Myodes glareolus), has triggered studies of environmental factors driving these infections. NE infections have been shown to occur in specific geographical areas characterized by environmental factors that influence the distribution and dynamics of host populations and virus persistence in the soil. Here, we review the influence of environmental conditions (including climate factors, food availability and habitat conditions) with respect to incidence in humans and seroprevalence in rodents, considering both direct and indirect transmission pathways. For each type of environmental factor, results and discrepancies between studies are presented and examined in the light of biological hypotheses. Overall, food availability and temperature appear to be the main drivers of host seroprevalence and NE incidence, but data quality and statistical approaches varied greatly among studies. We highlight the issues that now need to be addressed and suggest improvements for study design in regard to the current knowledge on hantavirus epidemiology. © 2016 Blackwell Verlag GmbH.

  8. Seroprevalence of Marek's Disease Virus antibody in some poultry ...

    African Journals Online (AJOL)

    This study reports a survey of Marek's disease virus (MDV) antibody done in 21 selected poultry flocks in Lagos, Ogun and Oyo states of southwestern Nigeria. A total of 315 serum samples were examined using the Enzyme Linked Immunosorbent Assay (ELISA) technique. Marek's disease virus antibody was present in ...

  9. Modification of the Host Cell Lipid Metabolism Induced by Hypolipidemic Drugs Targeting the Acetyl Coenzyme A Carboxylase Impairs West Nile Virus Replication.

    Science.gov (United States)

    Merino-Ramos, Teresa; Vázquez-Calvo, Ángela; Casas, Josefina; Sobrino, Francisco; Saiz, Juan-Carlos; Martín-Acebes, Miguel A

    2016-01-01

    West Nile virus (WNV) is a neurotropic flavivirus transmitted by the bite of mosquitoes that causes meningitis and encephalitis in humans, horses, and birds. Several studies have highlighted that flavivirus infection is highly dependent on cellular lipids for virus replication and infectious particle biogenesis. The first steps of lipid synthesis involve the carboxylation of acetyl coenzyme A (acetyl-CoA) to malonyl-CoA that is catalyzed by the acetyl-CoA carboxylase (ACC). This makes ACC a key enzyme of lipid synthesis that is currently being evaluated as a therapeutic target for different disorders, including cancers, obesity, diabetes, and viral infections. We have analyzed the effect of the ACC inhibitor 5-(tetradecyloxy)-2-furoic acid (TOFA) on infection by WNV. Lipidomic analysis of TOFA-treated cells confirmed that this drug reduced the cellular content of multiple lipids, including those directly implicated in the flavivirus life cycle (glycerophospholipids, sphingolipids, and cholesterol). Treatment with TOFA significantly inhibited the multiplication of WNV in a dose-dependent manner. Further analysis of the antiviral effect of this drug showed that the inhibitory effect was related to a reduction of viral replication. Furthermore, treatment with another ACC inhibitor, 3,3,14,14-tetramethylhexadecanedioic acid (MEDICA 16), also inhibited WNV infection. Interestingly, TOFA and MEDICA 16 also reduced the multiplication of Usutu virus (USUV), a WNV-related flavivirus. These results point to the ACC as a druggable cellular target suitable for antiviral development against WNV and other flaviviruses. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  10. Seroprevalence of Toxoplasma gondii infection in feral cats in Qatar.

    Science.gov (United States)

    Boughattas, Sonia; Behnke, Jerzy; Sharma, Aarti; Abu-Madi, Marawan

    2017-01-18

    Cats are essential in the life cycle of Toxoplasma gondii as they can shed the environmentally resistant oocysts after acquiring infection. Human populations living in cities with high densities of feral cats are therefore likely to be at risk of infection. The current study is the first to estimate the seroprevalence of T. gondii in the feral cat population in Qatar. We investigated the seroprevalence of T. gondii among 495 adult cats from urban and suburban districts in Qatar. Using results from the Modified Agglutination Test, we fitted statistical models with host sex, area and season as explanatory factors and seropositivity as the outcome. The analysis revealed an overall seroprevalence of 82%. Seroprevalence was significantly higher in the summer season (P = 0.006). No significant difference was detected (P > 0.05) between seroprevalence in female and male cats and in cats from urban and suburban districts of Qatar. Despite the seasonal difference, the observed seroprevalence of T. gondii suggests high environmental contamination throughout the year, with some female cats generating more intense responses compared to males. Both findings merit further investigations.

  11. Seroprevalence Of Toxoplasma gondii In Nazaret Town, Ethiopia ...

    African Journals Online (AJOL)

    Objective: To determine the seroprevalence of toxoplasmosis, assess its zoonotic importance and identify factors associated with seroprevalence. Methods: Questionnaire survey was conducted on 65 serum samples collected from male and female urban and peri-urban residents aged between 15 days and 65 years.

  12. Evaluation of Nucleic Acid Preservation Cards for West Nile Virus Testing in Dead Birds

    Science.gov (United States)

    Foss, Leslie; Reisen, William K.; Fang, Ying; Kramer, Vicki; Padgett, Kerry

    2016-01-01

    The California West Nile virus (WNV) Dead Bird Surveillance Program (DBSP) is an important component of WNV surveillance in the state. We evaluated FTA™ and RNASound™ cards as an alternative method for sampling dead birds for WNV molecular testing as these cards allow for more cost effective, rapid, and safer diagnostic sampling than the shipment of bird carcasses. To evaluate accuracy of results among avian sampling regimes, Reverse-Transcription Polymerase Chain Reaction (RT-PCR) results from FTA™ and RNASound™ cards were compared with results from kidney tissue, brain tissue, or oral swabs in lysis buffer in 2012–2013. In addition, RT-PCR results were compared with results from oral swabs tested by rapid antigen tests (RAMP™ and VecTOR™). While test results from the cards were not as sensitive as kidney tissue testing, they were more likely to provide accurate results than rapid antigen tests, and detected WNV in corvids as well as in other passerines, raptors, and waterfowl. Overall, WNV RT-PCR cycle threshold (Ct) scores from the cards were higher than those from tissue testing, but both card products displayed high sensitivity and specificity. American Crow samples provided the highest sensitivity. The cards also proved to be easier and more convenient vehicles for collecting and shipping samples, and in 2014 our program launched use of RNASound™ cards in the DBSP. Both FTA™ and RNASound™ products displayed 96% agreement with tissue results and are an adequate alternative sampling method for WNV dead bird testing. PMID:27341492

  13. Evaluation of Nucleic Acid Preservation Cards for West Nile Virus Testing in Dead Birds.

    Directory of Open Access Journals (Sweden)

    Leslie Foss

    Full Text Available The California West Nile virus (WNV Dead Bird Surveillance Program (DBSP is an important component of WNV surveillance in the state. We evaluated FTA™ and RNASound™ cards as an alternative method for sampling dead birds for WNV molecular testing as these cards allow for more cost effective, rapid, and safer diagnostic sampling than the shipment of bird carcasses. To evaluate accuracy of results among avian sampling regimes, Reverse-Transcription Polymerase Chain Reaction (RT-PCR results from FTA™ and RNASound™ cards were compared with results from kidney tissue, brain tissue, or oral swabs in lysis buffer in 2012-2013. In addition, RT-PCR results were compared with results from oral swabs tested by rapid antigen tests (RAMP™ and VecTOR™. While test results from the cards were not as sensitive as kidney tissue testing, they were more likely to provide accurate results than rapid antigen tests, and detected WNV in corvids as well as in other passerines, raptors, and waterfowl. Overall, WNV RT-PCR cycle threshold (Ct scores from the cards were higher than those from tissue testing, but both card products displayed high sensitivity and specificity. American Crow samples provided the highest sensitivity. The cards also proved to be easier and more convenient vehicles for collecting and shipping samples, and in 2014 our program launched use of RNASound™ cards in the DBSP. Both FTA™ and RNASound™ products displayed 96% agreement with tissue results and are an adequate alternative sampling method for WNV dead bird testing.

  14. Prevalence of hepatitis D virus infection in sub-Saharan Africa: a systematic review and meta-analysis.

    Science.gov (United States)

    Stockdale, Alexander J; Chaponda, Mas; Beloukas, Apostolos; Phillips, Richard Odame; Matthews, Philippa C; Papadimitropoulos, Athanasios; King, Simon; Bonnett, Laura; Geretti, Anna Maria

    2017-10-01

    Hepatitis D virus (also known as hepatitis delta virus) can establish a persistent infection in people with chronic hepatitis B, leading to accelerated progression of liver disease. In sub-Saharan Africa, where HBsAg prevalence is higher than 8%, hepatitis D virus might represent an important additive cause of chronic liver disease. We aimed to establish the prevalence of hepatitis D virus among HBsAg-positive populations in sub-Saharan Africa. We systematically reviewed studies of hepatitis D virus prevalence among HBsAg-positive populations in sub-Saharan Africa. We searched PubMed, Embase, and Scopus for papers published between Jan 1, 1995, and Aug 30, 2016, in which patient selection criteria and geographical setting were described. Search strings included sub-Saharan Africa, the countries therein, and permutations of hepatitis D virus. Cohort data were also added from HIV-positive populations in Malawi and Ghana. Populations undergoing assessment in liver disease clinics and those sampled from other populations (defined as general populations) were analysed. We did a meta-analysis with a DerSimonian-Laird random-effects model to calculate a pooled estimate of hepatitis D virus seroprevalence. Of 374 studies identified by our search, 30 were included in our study, only eight of which included detection of hepatitis D virus RNA among anti-hepatitis D virus seropositive participants. In west Africa, the pooled seroprevalence of hepatitis D virus was 7·33% (95% CI 3·55-12·20) in general populations and 9·57% (2·31-20·43) in liver-disease populations. In central Africa, seroprevalence was 25·64% (12·09-42·00) in general populations and 37·77% (12·13-67·54) in liver-disease populations. In east and southern Africa, seroprevalence was 0·05% (0·00-1·78) in general populations. The odds ratio for anti-hepatitis D virus detection among HBsAg-positive patients with liver fibrosis or hepatocellular carcinoma was 5·24 (95% CI 2·74-10·01; psub

  15. Rural-urban comparisons of dengue seroprevalence in Malaysia

    Directory of Open Access Journals (Sweden)

    Cheng Hoon Chew

    2016-08-01

    Full Text Available Abstract Background Each year an estimated 390 million dengue infections occur worldwide. In Malaysia, dengue is a growing public health concern but estimate of its disease burden remains uncertain. We compared the urban-rural difference of dengue seroprevalence and determined age-specific dengue seroprevalence in Malaysia. Methods We undertook analysis on 11,821 subjects from six seroprevalence surveys conducted in Malaysia between 2001 and 2013, which composed of five urban and two rural series. Results Prevalence of dengue increased with age in both urban and rural locations in Malaysia, which exceeded 90 % among those aged 70 years or beyond. The age-specific rates of the 5 urban surveys overlapped without clear separation among them, while prevalence was lower in younger subjects in rural series than in urban series, the trend reversed in older subjects. There were no differences in the seroprevalence by gender, ethnicity or region. Poisson regression model confirmed the prevalence have not changed in urban areas since 2001 but in rural areas, there was a significant positive time trend such that by year 2008, rural prevalence was as high as in urban areas. Conclusion Dengue seroprevalence has stabilized but persisted at a high level in urban areas since 2001, and is fast stabilizing in rural areas at the same high urban levels by 2008. The cumulative seroprevalence of dengue exceeds 90 % by the age of 70 years, which translates into 16.5 million people or 55 % of the total population in Malaysia, being infected by dengue by 2013.

  16. Rural-urban comparisons of dengue seroprevalence in Malaysia.

    Science.gov (United States)

    Chew, Cheng Hoon; Woon, Yuan Liang; Amin, Faridah; Adnan, Tassha H; Abdul Wahab, Asmah Hani; Ahmad, Zul Edzhar; Bujang, Mohd Adam; Abdul Hamid, Abdul Muneer; Jamal, Rahman; Chen, Wei Seng; Hor, Chee Peng; Yeap, Lena; Hoo, Ling Ping; Goh, Pik Pin; Lim, Teck Onn

    2016-08-18

    Each year an estimated 390 million dengue infections occur worldwide. In Malaysia, dengue is a growing public health concern but estimate of its disease burden remains uncertain. We compared the urban-rural difference of dengue seroprevalence and determined age-specific dengue seroprevalence in Malaysia. We undertook analysis on 11,821 subjects from six seroprevalence surveys conducted in Malaysia between 2001 and 2013, which composed of five urban and two rural series. Prevalence of dengue increased with age in both urban and rural locations in Malaysia, which exceeded 90 % among those aged 70 years or beyond. The age-specific rates of the 5 urban surveys overlapped without clear separation among them, while prevalence was lower in younger subjects in rural series than in urban series, the trend reversed in older subjects. There were no differences in the seroprevalence by gender, ethnicity or region. Poisson regression model confirmed the prevalence have not changed in urban areas since 2001 but in rural areas, there was a significant positive time trend such that by year 2008, rural prevalence was as high as in urban areas. Dengue seroprevalence has stabilized but persisted at a high level in urban areas since 2001, and is fast stabilizing in rural areas at the same high urban levels by 2008. The cumulative seroprevalence of dengue exceeds 90 % by the age of 70 years, which translates into 16.5 million people or 55 % of the total population in Malaysia, being infected by dengue by 2013.

  17. Prevalence of Antibodies to H9N2 Avian Influenza Virus in Backyard Chickens around Maharlou Lake in Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Mehdi Hadipour*, Gholamhossein Habibi and Amir Vosoughi

    2011-06-01

    Full Text Available Backyard chickens play an important role in the epidemiology of H9N2 avian influenza virus infection. Close contact of backyard chickens with migratory birds, especially with aquatic birds, as well as neighboring poultry farms, may pose the risk of transmitting avian influenza virus, but little is known about the disease status of backyard poultry. A H9N2 avian influenza virus seroprevalence survey was carried out in 500 backyard chickens from villages around Maharlou lake in Iran, using the hemagglutination-inhibition (HI test. The studied backyard chickens had not been previously vaccinated and showed no clinical signs of disease. The overall HI titer and seroprevalence against H9N2 were 7.73 and 81.6%, respectively.

  18. Economics of One Health: Costs and benefits of integrated West Nile virus surveillance in Emilia-Romagna.

    Directory of Open Access Journals (Sweden)

    Giulia Paternoster

    Full Text Available Since 2013 in Emilia-Romagna, Italy, surveillance information generated in the public health and in the animal health sectors has been shared and used to guide public health interventions to mitigate the risk of West Nile virus (WNV transmission via blood transfusion. The objective of the current study was to identify and estimate the costs and benefits associated with this One Health surveillance approach, and to compare it to an approach that does not integrate animal health information in blood donations safety policy (uni-sectoral scenario. Costs of human, animal, and entomological surveillance, sharing of information, and triggered interventions were estimated. Benefits were quantified as the averted costs of potential human cases of WNV neuroinvasive disease associated to infected blood transfusion. In the 2009-2015 period, the One Health approach was estimated to represent a cost saving of €160,921 compared to the uni-sectoral scenario. Blood donation screening was the main cost for both scenarios. The One Health approach further allowed savings of €1.21 million in terms of avoided tests on blood units. Benefits of the One Health approach due to short-term costs of hospitalization and compensation for transfusion-associated disease potentially avoided, were estimated to range from €0 to €2.98 million according to the probability of developing WNV neuroinvasive disease after receiving an infected blood transfusion.

  19. Seroprevalence of Ebola virus infection in Bombali District, Sierra Leone

    Directory of Open Access Journals (Sweden)

    Nadege Goumkwa Mafopa

    2017-12-01

    Full Text Available A serosurvey of anti-Ebola Zaire virus nucleoprotein IgG prevalence was carried out among Ebola virus disease survivors and their Community Contacts in Bombali District, Sierra Leone. Our data suggest that the specie of Ebola virus (Zaire responsible of the 2013-2016 epidemic in West Africa may cause mild or asymptomatic infection in a proportion of cases, possibly due to an efficient immune response.

  20. Change in Dengue and Japanese Encephalitis Seroprevalence Rates in Sri Lanka

    Science.gov (United States)

    Jeewandara, Chandima; Gomes, Laksiri; Paranavitane, S. A.; Tantirimudalige, Mihiri; Panapitiya, Sumedha Sandaruwan; Jayewardene, Amitha; Fernando, Samitha; Fernando, R. H.; Prathapan, Shamini

    2015-01-01

    Background Sri Lanka has been affected by epidemics of dengue infections for many decades and the incidence and severity of dengue infections have been rising each year. Therefore, we investigated the age stratified seroprevalence of dengue infections in order to facilitate future dengue vaccine strategies. In addition, since the symptomatic dengue infections have increased during the past few decades, we also investigated the possible association with Japanese Encephalitis Virus (JEV) antibody seropositivity with symptomatic dengue in a community cohort in Sri Lanka. Methods 1689 healthy individuals who were attending a primary health care facility were recruited. Dengue and JEV antibody status was determined in all individuals and JEV vaccination status was recorded. Results 1152/1689 (68.2%) individuals were seropositive for dengue and only 133/1152 (11.5%) of them had been hospitalized to due to dengue. A significant and positive correlation was observed for dengue antibody seropositivity and age in children (Spearmans R = 0.84, p = 0.002) and in adults (Spearmans R = 0.96, p = 0.004). We observed a significant rise in the age stratified seroprevalence rates in children over a period of 12 years. For instance, in year 2003 the annual seroconversion rate was 1.5% per annum, which had risen to 3.79% per annum by 2014. We also found that both adults (pdengue were more likely to be seropositive for JEV antibodies. However, 244 (91.4%) of adults who were seropositive for JEV had not had the JEV vaccine. Conclusions Dengue seroprevalence rates have risen significantly over the last 12 years in Sri Lanka, possibly due to increased transmission. As individuals who were hospitalized due to dengue were more likely to be seropositive for JEV, the possibility of cross-reactive assays and/or of JEV infection on immunity to the DENV and clinical disease severity should be further investigated. PMID:26696417

  1. A High Diversity of Eurasian Lineage Low Pathogenicity Avian Influenza A Viruses Circulate among Wild Birds Sampled in Egypt

    Science.gov (United States)

    Gerloff, Nancy A.; Jones, Joyce; Simpson, Natosha; Balish, Amanda; ElBadry, Maha Adel; Baghat, Verina; Rusev, Ivan; de Mattos, Cecilia C.; de Mattos, Carlos A.; Zonkle, Luay Elsayed Ahmed; Kis, Zoltan; Davis, C. Todd; Yingst, Sam; Cornelius, Claire; Soliman, Atef; Mohareb, Emad; Klimov, Alexander; Donis, Ruben O.

    2013-01-01

    Surveillance for influenza A viruses in wild birds has increased substantially as part of efforts to control the global movement of highly pathogenic avian influenza A (H5N1) virus. Studies conducted in Egypt from 2003 to 2007 to monitor birds for H5N1 identified multiple subtypes of low pathogenicity avian influenza A viruses isolated primarily from migratory waterfowl collected in the Nile Delta. Phylogenetic analysis of 28 viral genomes was performed to estimate their nearest ancestors and identify possible reassortants. Migratory flyway patterns were included in the analysis to assess gene flow between overlapping flyways. Overall, the viruses were most closely related to Eurasian, African and/or Central Asian lineage low pathogenicity viruses and belonged to 15 different subtypes. A subset of the internal genes seemed to originate from specific flyways (Black Sea-Mediterranean, East African-West Asian). The remaining genes were derived from a mixture of viruses broadly distributed across as many as 4 different flyways suggesting the importance of the Nile Delta for virus dispersal. Molecular clock date estimates suggested that the time to the nearest common ancestor of all viruses analyzed ranged from 5 to 10 years, indicating frequent genetic exchange with viruses sampled elsewhere. The intersection of multiple migratory bird flyways and the resulting diversity of influenza virus gene lineages in the Nile Delta create conditions favoring reassortment, as evident from the gene constellations identified by this study. In conclusion, we present for the first time a comprehensive phylogenetic analysis of full genome sequences from low pathogenic avian influenza viruses circulating in Egypt, underscoring the significance of the region for viral reassortment and the potential emergence of novel avian influenza A viruses, as well as representing a highly diverse influenza A virus gene pool that merits continued monitoring. PMID:23874653

  2. Serologic survey of wild boars for mosquito-borne viruses in South Moravia (Czech Republic)

    Czech Academy of Sciences Publication Activity Database

    Halouzka, Jiří; Juřicová, Zina; Janková, J.; Hubálek, Zdeněk

    2008-01-01

    Roč. 53, č. 5 (2008), s. 266-271 ISSN 0375-8427 R&D Projects: GA AV ČR IAA600930611 EU Projects: European Commission(XE) 10284 - EDEN Institutional research plan: CEZ:AV0Z60930519 Keywords : antibodies * West Nile virus * Tahyna virus * Batai virus * Sindbis virus * swine Subject RIV: EE - Microbiology, Virology Impact factor: 0.659, year: 2008 http://old.vri.cz/docs/vetmed/53-5-266.pdf

  3. Hepatitis B virus in drug users in France

    DEFF Research Database (Denmark)

    Brouard, C; Pillonel, J; Sogni, P

    2017-01-01

    People who use drugs (PWUD) are a key population for hepatitis B virus (HBV) vaccination and screening. We aimed to estimate the seroprevalence of HBs antigen (HBsAg) and self-reported HBV vaccination history in French PWUD attending harm reduction centres using data from the ANRS-Coquelicot mult...

  4. BLACK-BACKED JACKAL EXPOSURE TO RABIES VIRUS, CANINE DISTEMPER VIRUS, AND BACILLUS ANTHRACIS IN ETOSHA NATIONAL PARK, NAMIBIA

    Science.gov (United States)

    Bellan, Steve E.; Cizauskas, Carrie A.; Miyen, Jacobeth; Ebersohn, Karen; Küsters, Martina; Prager, Katie; Van Vuuren, Moritz; Sabeta, Claude; Getz, Wayne M.

    2017-01-01

    Canine distemper virus (CDV) and rabies virus (RABV) occur worldwide in wild carnivore and domestic dog populations and pose threats to wildlife conservation and public health. In Etosha National Park (ENP), Namibia, anthrax is endemic and generates carcasses frequently fed on by an unusually dense population of black-backed jackals (Canis mesomelas). Using serology and phylogenetic analyses (on samples obtained from February, 2009 to July, 2010), and historical mortality records (1975–2011), we assessed jackal exposure to Bacillus anthracis (BA; the causal bacterial agent of anthrax), CDV, and RABV. Seroprevalence to all three pathogens was relatively high with 95% (n = 86), 73% (n = 86), and 9% (n = 81) of jackals exhibiting antibodies to BA, CDV, and RABV, respectively. Exposure to BA, as assessed with an anti-Protective Antigen ELISA test, increased significantly with age and all animals >1 yr old tested positive. Seroprevalence of exposure to CDV also increased significantly with age, with similar age-specific trends during both years of the study. No significant effect of age was found on RABV seroprevalence. Three of the seven animals exhibiting immunity to RABV were monitored for more than one year after sampling and did not succumb to the disease. Mortality records revealed that rabid animals are destroyed nearly every year inside the ENP tourist camps. Phylogenetic analyses demonstrated that jackal RABV in ENP is part of the same transmission cycle as other dog-jackal RABV cycles in Namibia. PMID:22493112

  5. Seroprevalence and S7 gene characterization of bluetongue virus in the West of Iran

    Directory of Open Access Journals (Sweden)

    Mohammad Khezri

    Full Text Available Aim: The objective of this study was conducted to determine the seroprevalence and S7 gene characterization of BTV of sheep in the West of Iran, during 2007-2008. Materials and Methods: A total 372 sheep blood samples were collected from known seropositive regions in the West of Iran. Anti-BTV antibodies were detected in the serum samples by group specific, c-ELISA. Extractions of the dsRNA from whole blood samples were carried out. The One-step RT-PCR kit was used for the detection of S7 BTV gene in the blood samples. PCR products of the first amplification (RT-PCR were used; template in the nested PCR. Products were separated by 1.2% Agarose gel electrophoresis. Nested PCR products of S7 segment from positive samples and the reference strain; BTV1 (RSA vvvv/01 were prepared for sequencing. All sequences were subjected to multiple sequence alignments and phylogenetic analysis. Results: The results showed widespread presence of the anti-BTV antibodies in the province's sheep population, where 46.77% of the tested sera were positive on ELISA. Bluetongue viruses were diagnosed in some animals by RT-PCR and nested PCR, by targeting S7 segment. This genome segment was sequenced and analyzed in four samples as a conserved gene in BTV serogroup. This group was very similar to the West BTV strains from US, Africa and Europe. This clustered was categorized with BTV4 from Turkey. Conclusion: Increases in epidemic disease may constitute a serious problem for Iran's rural economy in future, and the situation is likely to worsen in the next few years as the proportion of unvaccinated livestock increases. [Vet World 2012; 5(9.000: 549-555

  6. Alarming incidence of hepatitis C virus re-infection after treatment of sexually acquired acute hepatitis C virus infection in HIV-infected MSM

    NARCIS (Netherlands)

    Lambers, Femke A. E.; Prins, Maria; Thomas, Xiomara; Molenkamp, Richard; Kwa, David; Brinkman, Kees; van der Meer, Jan T. M.; Schinkel, Janke; Countinho, R.; Reesink, H.; van Baarle, D.; Smit, C.; Gras, L.; van der Veldt, W.

    2011-01-01

    Recent data indicate that seroprevalence of sexually transmitted hepatitis C virus (HCV) infection among MSM is stabilizing in Amsterdam. However, little is known about the incidence of HCV re-infection in MSM who have cleared their HCV infection. We, therefore, studied the incidence of re-infection

  7. Control Over the Nile: Implications across Nations

    Science.gov (United States)

    2010-06-01

    states is evident in the 1959 Full Utilization of the Nile Waters Agreement between Egypt and the Sudan. Of the Nile’s annual average water yield of...grain, maize —has been falling. Kenya saw a 22 per cent decrease in 2000 from the 1998 harvest and a 36 per cent decrease from the 1999 harvest—leading...incorporated in a Nile water resource-sharing regime. The potential for Nile basin conflict or cooperation revolves around, first, the gap between water

  8. Original Research Hepatitis B virus seroprevalence among ...

    African Journals Online (AJOL)

    genetic markers, and liver biopsy, amongst others.9,10 In. Malawi, screening for hepatitis B virus surface antigen. (HBsAg) in public hospitals .... produced in response to the core HBV antigen and persist for life, suggesting a past horizontal transmission in childhood and adulthood.21 Detection of HBV DNA could be useful.

  9. Seroprevalence of HSV-1 and HSV-2 antibodies in Canadian women screened for enrolment in a herpes simplex virus vaccine trial.

    Science.gov (United States)

    Gorfinkel, I S; Aoki, F; McNeil, S; Dionne, M; Shafran, S D; Zickler, P; Halperin, S; Langley, J; Bellamy, A; Schulte, J; Heineman, T; Belshe, R

    2013-05-01

    Herpes simplex virus 1 and 2 (HSV-1 and HSV-2) infections continue to be among the most common and unrecognized sexually transmitted infections in the world. Although treatable, HSV-1 and HSV-2 infections remain incurable. Hence, there is interest in the development of a vaccine to prevent genital herpes. As part of a multicentre, randomized, placebo-controlled trial to test such a vaccine, healthy women 18-30 years were enrolled as volunteers in several Canadian centres between 2005 and 2007. This study reports the seroprevalence of HSV-1 and HSV-2 antibodies in this group. A total of 2694 adult female volunteers in Canada with no known history of herpes simplex were screened for HSV antibodies using Western blot assay (the gold standard for diagnosis of HSV) for potential participation in a randomized, double-blind efficacy field trial of a herpes simplex vaccine. This trial provides a unique opportunity to examine the prevalence of antibodies to HSV-1 and of antibodies to HSV-2 in women with no known history of herpes simplex infection. The prevalence of antibodies to HSV-1 and to HSV-2 is compared with that found in previous Canadian studies that focused on a more general population. The overall seroprevalence of antibody to HSV-1 was 43%; that of HSV-2 was 2.5% and seropositivity to both was 2%. The prevalence of antibody to both HSV-1 and to HSV-2 increased with age. Seronegativity to both HSV-1 and HSV-2 was 56% in participating centres with populations under 250,000 and 46% in participating centres with populations over 250,000. Significant racial differences in seropositivity to HSV-1 and to HSV-2 were noted. The likelihood of participants being seropositive to HSV-1 and to HSV-2 was found to increase with age and to positively correlate with the population of the city in which they resided. Hypotheses are proposed to account for differences in racial seropositivity to HSV-1 and to HSV-2.

  10. An Integrated Hydrological and Water Management Study of the Entire Nile River System - Lake Victoria to Nile Delta

    Science.gov (United States)

    Habib, Shahid; Zaitchik, Benjamin; Alo, Clement; Ozdogan, Mutlu; Anderson, Martha; Policelli, Fritz

    2011-01-01

    The Nile basin River system spans 3 million km(exp 2) distributed over ten nations. The eight upstream riparian nations, Ethiopia, Eretria, Uganda, Rwanda, Burundi, Congo, Tanzania and Kenya are the source of approximately 86% of the water inputs to the Nile, while the two downstream riparian countries Sudan and Egypt, presently rely on the river's flow for most of the their needs. Both climate and agriculture contribute to the complicated nature of Nile River management: precipitation in the headwaters regions of Ethiopia and Lake Victoria is variable on a seasonal and inter-annual basis, while demand for irrigation water in the arid downstream region is consistently high. The Nile is, perhaps, one of the most difficult trans-boundary water issue in the world, and this study would be the first initiative to combine NASA satellite observations with the hydrologic models study the overall water balance in a to comprehensive manner. The cornerstone application of NASA's Earth Science Research Results under this project are the NASA Land Data Assimilation System (LDAS) and the USDA Atmosphere-land Exchange Inverse (ALEXI) model. These two complementary research results are methodologically independent methods for using NASA observations to support water resource analysis in data poor regions. Where an LDAS uses multiple sources of satellite data to inform prognostic simulations of hydrological process, ALEXI diagnoses evapotranspiration and water stress on the basis of thermal infrared satellite imagery. Specifically, this work integrates NASA Land Data Assimilation systems into the water management decision support systems that member countries of the Nile Basin Initiative (NBI) and Regional Center for Mapping of Resources for Development (RCMRD, located in Nairobi, Kenya) use in water resource analysis, agricultural planning, and acute drought response to support sustainable development of Nile Basin water resources. The project is motivated by the recognition that

  11. Seroprevalence of HDV infection in HBsAg positive population in Ismailia, Egypt.

    Science.gov (United States)

    Gomaa, Nahed I M; Metwally, Lobna A; Nemr, Nader; Younis, Soha

    2013-01-01

    Hepatitis D virus (HDV) is a defective RNA virus that needs hepatitis B surface antigen (HBsAg) from HBV for transmission. HDV can lead to fulminant hepatitis and the progression of chronic liver damage in patients with chronic hepatitis B. The aim of this study was to determine the seroprevalence of HDV among HBsAg positive individuals in Ismailia, Egypt. Serum samples were collected from 170 HBsAg positive healthy individuals from Suez Canal University blood bank over a one year period. All of them were seeking blood donation and found to be HBsAg positive during viral hepatitis screening workups which is routinely done prior to donation. Serum samples were screened for IgG antibodies to hepatitis delta virus (HDV) using enzyme-linked immunosorbent assay (ELISA) method. Anti-HDV antibodies were detected in 8 (4.7%) individuals aged from 29-43 years. Liver function tests showed that serum ALT and AST levels were elevated in the HBsAglanti-HDV positive cases. It is concluded that the rate of HDV infection in Ismailia is high and further investigation is needed to validate the findings and raise awareness about the risk of dual HBV and HDV infection.

  12. First Report of Hepatitis E Virus Infection in Sika Deer in China

    OpenAIRE

    Zhang, Xiao-Xuan; Qin, Si-Yuan; Zhang, Yuan; Meng, Qing-Feng; Jiang, Jing; Yang, Gui-Lian; Zhao, Quan; Zhu, Xing-Quan

    2015-01-01

    Hepatitis E virus (HEV), a single stranded RNA, nonenveloped virus, belongs to the genus Hepevirus, in the family of Hepeviridae. In this study, 46 (5.43%) out of the 847 serum samples from sika deer (Cervus nippon) were detected as seropositive with hepatitis E virus (HEV) by enzyme linked immunosorbent assay (ELISA). These samples were collected from Inner Mongolia and Jilin and Heilongjiang provinces in China, between October 2012 and October 2013. Seroprevalence of HEV infection in male a...

  13. Emergence of chikungunya seropositivity in healthy Malaysian adults residing in outbreak-free locations: Chikungunya seroprevalence results from the Malaysian Cohort

    Science.gov (United States)

    2013-01-01

    Background In 1998, Malaysia experienced its first chikungunya virus (CHIKV) outbreak in the suburban areas followed by another two in 2006 (rural areas) and 2008 (urban areas), respectively. Nevertheless, there is still a lack of documented data regarding the magnitude of CHIKV exposure in the Malaysian population. The aim of this study was to determine the extent of chikungunya virus infection in healthy Malaysian adults residing in outbreak-free locations. Methods A cross sectional study of chikungunya (CHIK) seroprevalence was carried out in 2009 amongst The Malaysian Cohort participants living in four states (Kuala Lumpur, Selangor, Pahang and Negeri Sembilan). A total of 945 participants were randomly identified for the study. Potential risk factors for CHIK infection were determined via questionnaires, and IgG antibodies against CHIK were detected by an enzyme-linked immunosorbent assay. Logistic regression identified risk factors associated with CHIK seropositivity, while geographical information system was used for visual and spatial analysis. Results From the 945 serum samples tested, 5.9% was positive for CHIK IgG. Being male, Malay, rural occupancy and Negeri Sembilan residency were identified as univariate predictors for CHIK seropositivity, while multivariate analysis identified being male and rural occupancy as risk factors. Conclusions This study provided evidence that CHIK is slowly emerging in Malaysia. Although the current baseline seroprevalence is low in this country, increasing number of CHIK cases reported to the Malaysia Ministry of Health imply the possibility of CHIK virus becoming endemic in Malaysia. PMID:23379541

  14. Human Immunodeficiency Virus (HIV) Seropositivity In African ...

    African Journals Online (AJOL)

    A seroprevalence study of Human immunodeficiency virus (HIV) infection in new patients attending the eye clinic of LAUTECH Teaching Hospital in Osogbo, Osun State, Nigeria showed that twenty-nine patients 2.7%) were positive to HIV1. No patient was positive to HIV 2. There were 21 males (72.4%) and 8 females ...

  15. Respiratory insufficiency correlated strongly with mortality of rodents infected with West Nile virus.

    Directory of Open Access Journals (Sweden)

    John D Morrey

    Full Text Available West Nile virus (WNV disease can be fatal for high-risk patients. Since WNV or its antigens have been identified in multiple anatomical locations of the central nervous system of persons or rodent models, one cannot know where to investigate the actual mechanism of mortality without careful studies in animal models. In this study, depressed respiratory functions measured by plethysmography correlated strongly with mortality. This respiratory distress, as well as reduced oxygen saturation, occurred beginning as early as 4 days before mortality. Affected medullary respiratory control cells may have contributed to the animals' respiratory insufficiency, because WNV antigen staining was present in neurons located in the ventrolateral medulla. Starvation or dehydration would be irrelevant in people, but could cause death in rodents due to lethargy or loss of appetite. Animal experiments were performed to exclude this possibility. Plasma ketones were increased in moribund infected hamsters, but late-stage starvation markers were not apparent. Moreover, daily subcutaneous administration of 5% dextrose in physiological saline solution did not improve survival or other disease signs. Therefore, infected hamsters did not die from starvation or dehydration. No cerebral edema was apparent in WNV- or sham-infected hamsters as determined by comparing wet-to-total weight ratios of brains, or by evaluating blood-brain-barrier permeability using Evans blue dye penetration into brains. Limited vasculitis was present in the right atrium of the heart of infected hamsters, but abnormal electrocardiograms for several days leading up to mortality did not occur. Since respiratory insufficiency was strongly correlated with mortality more than any other pathological parameter, it is the likely cause of death in rodents. These animal data and a poor prognosis for persons with respiratory insufficiency support the hypothesis that neurological lesions affecting respiratory

  16. Survey of malaria and anti-dengue virus IgG among febrile HIV-infected patients attending a tertiary hospital in Abuja, Nigeria.

    Science.gov (United States)

    Mustapha, Jelili Olaide; Emeribe, Anthony Uchenna; Nasir, Idris Abdullahi

    2017-01-01

    Dengue and malaria are infections, of great public health concern, especially in sub-Saharan Africa where the burden of HIV infection is high. This study was conducted to determine the seroprevalence of dengue virus IgG antibodies and dengue/malaria coinfection among febrile HIV-infected patients attending the University of Abuja Teaching Hospital, Gwagwalada, Abuja. In this cross-sectional study, blood samples from 178 consenting HIV-infected patients receiving antiretroviral therapy were collected and tested for plasmodiasis and anti-Dengue virus IgG using malaria microscopy and ELISA, respectively. Interviewer-based questionnaires were used to assess subjects' sociodemographic variables and dengue risk factors. Of the 178 screened participants, 44.4% were seropositive for dengue virus IgG antibody, whereas 29.2% were positive for Plasmodium falciparum. About 44.2% were positive for both dengue virus and P. falciparum . There was a statistical association between anti-dengue IgG and occupation ( p =0.03) but not with age, residential area, educational level and patients' gender ( p >0.05). Seroprevalence of anti-dengue specific IgG was relatively higher in participants who adopted protective measures. There was a statistical association between seroprevalence of anti-dengue IgG and adoption of preventive measures ( p <0.05). The high prevalence of malaria and dengue virus IgG indicates the need to strengthen vector control and dengue surveillance programs.

  17. Integrating Environmental and Mosquito Data to Model Disease: Evaluating Alternative Modeling Approaches for Forecasting West Nile Virus in South Dakota, USA

    Science.gov (United States)

    Davis, J. K.; Vincent, G. P.; Hildreth, M.; Kightlinger, L.; Carlson, C.; Wimberly, M. C.

    2017-12-01

    South Dakota has the highest annual incidence of human cases of West Nile virus (WNV) in all US states, and human cases can vary wildly among years; predicting WNV risk in advance is a necessary exercise if public health officials are to respond efficiently and effectively to risk. Case counts are associated with environmental factors that affect mosquitoes, avian hosts, and the virus itself. They are also correlated with entomological risk indices obtained by trapping and testing mosquitoes. However, neither weather nor insect data alone provide a sufficient basis to make timely and accurate predictions, and combining them into models of human disease is not necessarily straightforward. Here we present lessons learned in three years of making real-time forecasts of this threat to public health. Various methods of integrating data from NASA's North American Land Data Assimilation System (NLDAS) with mosquito surveillance data were explored in a model comparison framework. We found that a model of human disease summarizing weather data (by polynomial distributed lags with seasonally-varying coefficients) and mosquito data (by a mixed-effects model that smooths out these sparse and highly-variable data) made accurate predictions of risk, and was generalizable enough to be recommended in similar applications. A model based on lagged effects of temperature and humidity provided the most accurate predictions. We also found that model accuracy was improved by allowing coefficients to vary smoothly throughout the season, giving different weights to different predictor variables during different parts of the season.

  18. Epidemiology of west nile in europe and in the mediterranean basin.

    Science.gov (United States)

    Calistri, Paolo; Giovannini, Armando; Hubalek, Zdenek; Ionescu, Aurelia; Monaco, Federica; Savini, Giovanni; Lelli, Rossella

    2010-04-22

    In the last 30 years several cases of West Nile (WN) virus infection were reported in horses and humans in Europe and in the Mediterranean Basin. Most of them were determined by strains of the Lineage 1 included in the European Mediterranean/Kenyan cluster. Strains of this cluster are characterised by a moderate pathogenicity for horses and humans and limited or no pathogenicity for birds. In recent years, however, WN cases determined by strains grouped in the Israeli/American cluster of Lineage 1 or in the lineage 2 have been reported in Hungary and Austria. The role of migrating birds in introducing new viruses to Europe has been often demonstrated. The migratory birds, which may be infected in their African wintering places, carry the virus northward to European sites during spring migrations. In the past, the virus introduction determined occasional cases of WN. In the recent years, new epidemiological scenarios are developing. In few occasions it has been evidenced the capability of WNV strains of overwintering by using local birds and mosquitoes. Species of Culex amongst mosquitoes and magpies (Pica pica), carrion crows (Corvus corone) and rock pigeons (Columba livia) amongst resident birds are the most probable species involved in this hypothetical WND endemic cycle.

  19. Systematic analysis of protein identity between Zika virus and other arthropod-borne viruses.

    Science.gov (United States)

    Chang, Hsiao-Han; Huber, Roland G; Bond, Peter J; Grad, Yonatan H; Camerini, David; Maurer-Stroh, Sebastian; Lipsitch, Marc

    2017-07-01

    To analyse the proportions of protein identity between Zika virus and dengue, Japanese encephalitis, yellow fever, West Nile and chikungunya viruses as well as polymorphism between different Zika virus strains. We used published protein sequences for the Zika virus and obtained protein sequences for the other viruses from the National Center for Biotechnology Information (NCBI) protein database or the NCBI virus variation resource. We used BLASTP to find regions of identity between viruses. We quantified the identity between the Zika virus and each of the other viruses, as well as within-Zika virus polymorphism for all amino acid k -mers across the proteome, with k ranging from 6 to 100. We assessed accessibility of protein fragments by calculating the solvent accessible surface area for the envelope and nonstructural-1 (NS1) proteins. In total, we identified 294 Zika virus protein fragments with both low proportion of identity with other viruses and low levels of polymorphisms among Zika virus strains. The list includes protein fragments from all Zika virus proteins, except NS3. NS4A has the highest number (190 k -mers) of protein fragments on the list. We provide a candidate list of protein fragments that could be used when developing a sensitive and specific serological test to detect previous Zika virus infections.

  20. DNA barcode for genetic traceability of Nile Perch and Nile Tilapia

    International Nuclear Information System (INIS)

    Avossa, Valeria

    2017-01-01

    For this study, mitochondrial DNA was extracted from 55 fish samples (26 Nile Perch Samples and 29 Nile Tilapia Samples collected from 3 different Ugandan regions of Lake Victoria. In order to optimize the PCR method, we also extracted DNA from two other different fish samples: one from Italy and one from a Viennese market. The COI gene was amplified using universal primers (COI2, COI3, cocktails of 8 and 4 primers respectively). After the amplification step, the amplicons were analysed using gel electrophoresis , in order to establish that the set primers worked well in the samples. The positive results of an agarose gel electrophoresis analysis with the PCR amplicons (amplicons length ~700pb) are shown.