Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| identification of potential vectors of and detection of antibodies against rift valley fever virus in livestock during interepizootic periods. | to evaluate the prevalence of rift valley fever virus (rvfv) antibodies in livestock and presence of competent mosquito vectors of rvfv during an interepizootic period (iep) in kenya. | 2010 | 20433377 |
| rift valley fever virus immunity provided by a paramyxovirus vaccine vector. | rift valley fever virus (rvfv) causes recurrent large outbreaks among humans and livestock. although the virus is currently confined to the african continent and the arabian peninsula, there is a growing concern for rvfv incursions into countries with immunologically naïve populations. the rvfv structural glycoproteins gn and gc are preferred targets in the development of subunit vaccines that can be used to control future outbreaks. we here report the production of gn and gc by a recombinant va ... | 2010 | 20434545 |
| rift valley fever among febrile patients at new halfa hospital, eastern sudan. | since the first isolation of the rift valley fever virus (rvfv) in 1930s, there have been several epizootics outbreaks in the tropic mainly in africa including sudan. recognition of cases and diagnosis of rvf are critical for management and control of the disease. | 2010 | 20465791 |
| evaluation of the efficacy and safety of the rift valley fever clone 13 vaccine in sheep. | the efficacy and safety of the naturally attenuated rift valley fever (rvf) clone 13 vaccine were evaluated in ovines in three different experiments involving 38 ewes at different stages of pregnancy, their offsprings and four rams. in experiment 1, 4 rams and a total of 13 pregnant ewes were vaccinated and monitored during vaccination and after a challenge with a virulent rvf virus. the ewes were vaccinated at either 50 or 100 days of pregnancy and some were challenged after lambing. in experim ... | 2010 | 20470792 |
| rift valley fever in kenya: history of epizootics and identification of vulnerable districts. | since kenya first reported rift valley fever (rvf)-like disease in livestock in 1912, the country has reported the most frequent epizootics of rvf disease. to determine the pattern of disease spread across the country after its introduction in 1912, and to identify regions vulnerable to the periodic epizootics, annual livestock disease records at the department of veterinary services from 1910 to 2007 were analysed in order to document the number and location of rvf-infected livestock herds. a t ... | 2011 | 20478084 |
| distribution and seasonal activity of mosquitoes in al madinah al munwwrah, saudi arabia. | in this study, 2654 adults and mosquito larvae, which belong to 18 species and 4 genera, were collected: aedes (2 spp.), anopheles (7 spp.), culex (8 spp.) and culiseta (1 sp.). they were aedes caspius, ae. aegypti, anopheles. azaniae, an. d'thali, an. multicolor, an. rhodesiensis, an. stephensi, an. sub-pictus, an. turkhudi, culex laticinctus, cx. perexiguus, cx. pipiens, cx. quin-quefasciatus, cx. simpsoni, cx. theileri, cx. tritaeniorhynchus, cx. univittatus and culiseta longiareolata. a tota ... | 2010 | 20503600 |
| rift valley fever during rainy seasons, madagascar, 2008 and 2009. | during 2 successive rainy seasons, january 2008 through may 2008 and november 2008 through march 2009, rift valley fever virus (rvfv) caused outbreaks in madagascar. human and animal infections were confirmed on the northern and southern coasts and in the central highlands. analysis of partial sequences from rvfv strains showed that all were similar to the strains circulating in kenya during 2006-2007. a national cross-sectional serologic survey among slaughterhouse workers at high risk showed t ... | 2010 | 20507747 |
| molecular biology of rift valley fever virus. | rift valley fever virus (rvfv) causes large outbreaks of acute febrile and often fatal illness among humans and domesticated animals in sub-saharan africa and the arabian peninsula. rvfv is a member of the family bunyaviridae, genus phlebovirus. like all members of this large virus family, it contains a three-segmented genome of negative/ambisense strand rna, packaged into viral nucleocapsid protein, and enveloped by a lipid bilayer containing two viral glycoproteins. during the past years, ther ... | 2010 | 20517489 |
| structure of the rift valley fever virus nucleocapsid protein reveals another architecture for rna encapsidation. | rift valley fever virus (rvfv) is a negative-sense rna virus (genus phlebovirus, family bunyaviridae) that infects livestock and humans and is endemic to sub-saharan africa. like all negative-sense viruses, the segmented rna genome of rvfv is encapsidated by a nucleocapsid protein (n). the 1.93-a crystal structure of rvfv n and electron micrographs of ribonucleoprotein (rnp) reveal an encapsidated genome of substantially different organization than in other negative-sense rna virus families. the ... | 2010 | 20547879 |
| characterization of a sandfly fever sicilian virus isolated during a sandfly fever epidemic in turkey. | phleboviruses cause sandfly fever but isolates are rare. | 2010 | 20579934 |
| vaccination with dna plasmids expressing gn coupled to c3d or alphavirus replicons expressing gn protects mice against rift valley fever virus. | rift valley fever (rvf) is an arthropod-borne viral zoonosis. rift valley fever virus (rvfv) is an important biological threat with the potential to spread to new susceptible areas. in addition, it is a potential biowarfare agent. | 2010 | 20582312 |
| advances in rift valley fever research: insights for disease prevention. | the purpose was to review recent research on rift valley fever virus (rvfv) infection, encompassing four main areas: epidemiology and outbreak prediction, viral pathogenesis, human diagnostics and therapeutics, and vaccine and therapeutic candidates. | 2010 | 20613512 |
| arboviral encephalitides: transmission, emergence, and pathogenesis. | arthropod-borne viruses (arboviruses) are of paramount concern as a group of pathogens at the forefront of emerging and re-emerging diseases. although some arboviral infections are asymptomatic or present with a mild influenza-like illness, many are important human and veterinary pathogens causing serious illness ranging from rash and arthritis to encephalitis and hemorrhagic fever. here, we discuss arboviruses from diverse families (flaviviruses, alphaviruses, and the bunyaviridae) that are cau ... | 2010 | 20652430 |
| novel suspension cell-based vaccine production systems for rift valley fever virus-like particles. | rift valley fever virus (rvfv) is an arthropod-borne pathogen that often results in severe morbidity and mortality in both humans and livestock. as its geographic range continues to expand, it presents a real threat to naïve populations around the world by accidental introduction (e.g., the result of increased travel) or intentional release (e.g., a bioterror event). while there is a clear need for a safe and efficacious vaccine against this emerging and re-emerging pathogen, no fda-approved vac ... | 2010 | 20655330 |
| rift valley fever virus seroprevalence in human rural populations of gabon. | 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 distri ... | 2010 | 20668541 |
| [importation of infectious diseases to europe via animals and animal products: risks and pathways]. | importation of tropical infectious diseases to europe via animals and animal products. most emerging and resurgent diseases observed in france in recent decades have been zoonoses, and some have caused unprecedented health crises. the growing international trade in domestic and wild animals and foodstuffs of animal origin is contributing to the emergence or resurgence of such zoonoses, along with accidental or deliberate introduction of certain species into new geographical areas, and the recent ... | 2009 | 20669546 |
| rift valley fever: scientific pathways toward public health prevention and response. | 2010 | 20682899 | |
| an investigation of a major outbreak of rift valley fever in kenya: 2006-2007. | an outbreak of rift valley fever (rvf) occurred in kenya during november 2006 through march 2007. we characterized the magnitude of the outbreak through disease surveillance and serosurveys, and investigated contributing factors to enhance strategies for forecasting to prevent or minimize the impact of future outbreaks. of 700 suspected cases, 392 met probable or confirmed case definitions; demographic data were available for 340 (87%), including 90 (26.4%) deaths. male cases were more likely to ... | 2010 | 20682900 |
| risk factors for severe rift valley fever infection in kenya, 2007. | a large rift valley fever (rvf) outbreak occurred in kenya from december 2006 to march 2007. we conducted a study to define risk factors associated with infection and severe disease. a total of 861 individuals from 424 households were enrolled. two hundred and two participants (23%) had serologic evidence of acute rvf infection. of these, 52 (26%) had severe rvf disease characterized by hemorrhagic manifestations or death. independent risk factors for acute rvf infection were consuming or handli ... | 2010 | 20682901 |
| epidemiologic and clinical aspects of a rift valley fever outbreak in humans in tanzania, 2007. | in january 2007, an outbreak of rift valley fever (rvf) was detected among humans in northern tanzania districts. by the end of the outbreak in june, 2007, 511 suspect rvf cases had been recorded from 10 of the 21 regions of tanzania, with laboratory confirmation of 186 cases and another 123 probable cases. all confirmed rvf cases were located in the north-central and southern regions of the country, with an eventual fatality rate of 28.2% (n = 144). all suspected cases had fever; 89% had enceph ... | 2010 | 20682902 |
| rift valley fever virus epidemic in kenya, 2006/2007: the entomologic investigations. | in december 2006, rift valley fever (rvf) was diagnosed in humans in garissa hospital, kenya and an outbreak reported affecting 11 districts. entomologic surveillance was performed in four districts to determine the epidemic/epizootic vectors of rvf virus (rvfv). approximately 297,000 mosquitoes were collected, 164,626 identified to species, 72,058 sorted into 3,003 pools and tested for rvfv by reverse transcription-polymerase chain reaction. seventy-seven pools representing 10 species tested po ... | 2010 | 20682903 |
| pathologic studies on suspect animal and human cases of rift valley fever from an outbreak in eastern africa, 2006-2007. | rift valley fever (rvf) is an important viral zoonotic disease in africa with periodic outbreaks associated with severe disease, death, and economic hardship. during the 2006-2007 outbreaks in eastern africa, postmortem and necropsy tissue samples from 14 animals and 20 humans clinically suspected of rvf were studied with histopathologic evaluation and immunohistochemical (ihc) assays. six animal and 11 human samples had ihc evidence of rift valley fever virus (rvfv) antigens. we found that exte ... | 2010 | 20682904 |
| prediction, assessment of the rift valley fever activity in east and southern africa 2006-2008 and possible vector control strategies. | historical outbreaks of rift valley fever (rvf) since the early 1950s have been associated with cyclical patterns of the el niño/southern oscillation (enso) phenomenon, which results in elevated and widespread rainfall over the rvf endemic areas of africa. using satellite measurements of global and regional elevated sea surface temperatures, elevated rainfall, and satellite derived-normalized difference vegetation index data, we predicted with lead times of 2-4 months areas where outbreaks of rv ... | 2010 | 20682905 |
| an assessment of the regional and national socio-economic impacts of the 2007 rift valley fever outbreak in kenya. | although rift valley fever (rvf) has significant impacts on human health and livestock production, it can also induce significant (and often overlooked) economic losses among various stakeholders in the marketing chain. this work assesses and quantifies the multi-dimensional socio-economic impacts of the 2007 rvf outbreak in kenya based on a rapid assessment of livestock value chains in the northeast part of the country and a national macroeconomic analysis. although study results show negative ... | 2010 | 20682906 |
| rift valley fever outbreak in livestock in kenya, 2006-2007. | we analyzed the extent of livestock involvement in the latest rift valley fever (rvf) outbreak in kenya that started in december 2006 and continued until june 2007. when compared with previous rvf outbreaks in the country, the 2006-07 outbreak was the most extensive in cattle, sheep, goats, and camels affecting thousands of animals in 29 of 69 administrative districts across six of the eight provinces. this contrasted with the distribution of approximately 700 human rvf cases in the country, whe ... | 2010 | 20682907 |
| epidemiological assessment of the rift valley fever outbreak in kenya and tanzania in 2006 and 2007. | to capture lessons from the 2007 rift valley fever (rvf) outbreak, epidemiological studies were carried out in kenya and tanzania. somali pastoralists proved to be adept at recognizing symptoms of rvf and risk factors such as heavy rainfall and mosquito swarms. sandik, which means "bloody nose," was used by somalis to denote disease consistent with rvf. somalis reported that sandik was previously seen in 1997/98, the period of the last rvf epidemic. pastoralists communicated valuable epidemiolog ... | 2010 | 20682908 |
| the historical and recent impact of rift valley fever in africa. | 2010 | 20682909 | |
| decision-support tool for prevention and control of rift valley fever epizootics in the greater horn of africa. | in east africa, rift valley fever (rvf) usually occurs as explosive epizootics with prolonged inter-epidemic periods on the order of 8 to 10 years. the episodic nature of the disease and the rapid evolution of outbreaks create special challenges for its mitigation and control. following the events of the 2006 and 2007 rvf outbreak in east africa, decision-makers assembled their collective experiences in the form of a risk-based decision support tool to help guide responses in future emergencies. ... | 2010 | 20682910 |
| infectious lassa virus, but not filoviruses, is restricted by bst-2/tetherin. | bone marrow stromal antigen 2 (bst-2/tetherin) is a cellular membrane protein that inhibits the release of hiv-1. we show for the first time, using infectious viruses, that bst-2 also inhibits egress of arenaviruses but has no effect on filovirus replication and spread. specifically, infectious lassa virus (lasv) release significantly decreased or increased in human cells in which bst-2 was either stably expressed or knocked down, respectively. in contrast, replication and spread of infectious z ... | 2010 | 20686043 |
| the american society for virology--29th annual meeting. | the american society for virology 29th annual meeting, held in bozeman, mt, usa, included topics covering new vaccine technologies, delivery methods and treatments in the field of virology. this conference report highlights selected presentations on human norovirus (hunov), sars coronavirus and rift valley fever virus vaccine technologies; programmed cell death-1 (pd1) blockade and hyperacute alpha-gal platform technology methods; aerosol vaccination delivery; novel technologies to produce influ ... | 2010 | 20799142 |
| rift valley fever: scientific pathways to public health prevention and response. proceedings of a workshop. may 2008. nairobi. | 2010 | 20824895 | |
| the pathogenesis of rift valley fever virus in the mouse model. | detailed studies describing the pathogenesis of rift valley fever (rvf) virus (rvfv) in the mouse model are lacking. a fully characterized small animal model of rvf is needed to evaluate potential vaccines and therapeutics. in this study, we characterized the pathogenesis of rvfv throughout the disease course in mice. infection produced high-titer viremia and demonstrated rvfv tropism for a variety of tissue and individual cell types. overwhelming infection of hepatocytes, accompanied by apoptos ... | 2010 | 20850165 |
| replication of clone 13, a naturally attenuated avirulent isolate of rift valley fever virus, in aedes and culex mosquitoes. | rift valley fever virus continues to cause large outbreaks of acute and febrile illness among humans and domestic animals in africa. the high pathogenicity of the virus is mainly due to the non-structural protein derived from the s segment nss, which was shown to inhibit the type i interferon expression at the transcriptional level and to suppress host cell rna synthesis. clone 13, a naturally attenuated clone containing a deletion of 70% in nss, is a promising vaccine candidate as it has no pat ... | 2010 | 20854021 |
| experimental infection of young adult european breed sheep with rift valley fever virus field isolates. | the increasing interest in rift valley fever virus (rvfv) and its potential impact on naive animal populations deserve revisiting experimental reproduction of rvfv infection, particularly in those animal breeds for which no data about their susceptibility to rvfv infection have ever been recorded. in this study we show the susceptibility of 9-10 weeks old european sheep (ripollesa breed) to rvfv infection, showing a mild, subacute form of disease. four different viral isolates efficiently replic ... | 2010 | 20854022 |
| comparison of enzyme-linked immunosorbent assay-based techniques for the detection of antibody to rift valley fever virus in thermochemically inactivated sheep sera. | different enzyme-linked immunosorbent assay (elisa)-based techniques for the detection of antibodies to rift valley fever virus (rvfv) have been developed in recent years, but their diagnostic sensitivity was not directly compared. in addition, their use might still be restricted to high biocontainment facilities when sera to be tested are collected from viremic individuals. in this study, we report on direct comparison of various elisa forms for the detection of anti-rvfv antibody in preinactiv ... | 2010 | 20854023 |
| virus-like particles expressing the nucleocapsid gene as an efficient vaccine against rift valley fever virus. | rift valley fever virus (rvfv), a member of the family bunyaviridae, regularly accounts for large and severe outbreaks among humans and livestock in africa and arabia. therefore, safe and efficient vaccines are highly needed. here, we report the production of recombinant virus-like particles (vlps) that, in addition to their similarity to rvfv particles, are able to express the viral nucleocapsid (n) gene. a single inoculation of 1 × 10(6) of these n-vlps was sufficient to protect 100% of mice f ... | 2010 | 20854024 |
| interventions against west nile virus, rift valley fever virus, and crimean-congo hemorrhagic fever virus: where are we? | 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 crimean-congo hemorrhagic fever virus. to evaluate the status quo of control measures against these viruses, an arbo-zoonet meeting was held in istanbul, turkey, from 19 to 20 november 2009. the symposium c ... | 2010 | 20854026 |
| interview with dr. anthony r. fooks. interview by vicki glaser. | 2010 | 20854027 | |
| toscana virus induces interferon although its nss protein reveals antagonistic activity. | toscana virus (tosv) is a phlebotomus-transmitted virus that belongs to the family bunyaviridae and causes widespread infections in humans; about 30 % of these cases result in aseptic meningitis. in the present study, it was shown that tosv is an inducer of beta interferon (ifn-β), although its non-structural protein (nss) could inhibit the induction of ifn-β if expressed in a heterologous context. a recombinant rift valley fever virus expressing the tosv nss could suppress ifn-β expression in i ... | 2011 | 20861320 |
| protection of sheep against rift valley fever virus and sheep poxvirus with a recombinant capripoxvirus vaccine. | rift valley fever (rvf) is an epizootic viral disease of sheep that can be transmitted from sheep to humans, particularly by contact with aborted fetuses. a capripoxvirus (cpv) recombinant virus (rks1/rvfv) was developed, which expressed the rift valley fever virus (rvfv) gn and gc glycoproteins. these expressed glycoproteins had the correct size and reacted with monoclonal antibodies (mab) to native glycoproteins. mice vaccinated with rks1/rvfv were protected against rvfv challenge. sheep vacci ... | 2010 | 20876822 |
| a new mouse model reveals a critical role for host innate immunity in resistance to rift valley fever. | rift valley fever (rvf) is an arthropod-borne viral disease repeatedly reported in many african countries and, more recently, in saudi arabia and yemen. rvf virus (rvfv) primarily infects domesticated ruminants, resulting in miscarriage in pregnant females and death for newborns and young animals. it also has the ability to infect humans, causing a feverish syndrome, meningoencephalitis, or hemorrhagic fever. the various outcomes of rvfv infection in animals and humans argue for the existence of ... | 2010 | 20937849 |
| potential for north american mosquitoes (diptera: culicidae) to transmit rift valley fever virus. | to determine which arthropods should be targeted for control should rift valley fever virus (rvfv) be detected in north america, we evaluated culex erraticus (dyar and knab), culex erythrothorax dyar, culex nigripalpus theobald, culex pipiens l., culex quinquefasciatus say, culex tarsalis coquillett, aedes dorsalis (wiedemann), aedes vexans (meigen), anopheles quadrimaculatus say, and culicoides sonorensis wirth and jones from the western, midwestern, and southern united states for their ability ... | 2010 | 20939385 |
| risk assessment of the introduction of rift valley fever from the horn of africa to yemen via legal trade of small ruminants. | rift valley fever (rvf) is a mosquito-borne viral zoonosis of increasing global importance. occurring since 1930 across africa, it was detected for the first time in saudi arabia and yemen in september 2000, leading to human deaths and major losses in livestock populations. assuming the virus has not survived in yemen or has been circulating at a low level, authors qualitatively assessed the likelihood of "re-introduction" of rvf into yemen through the legal importation of small ruminants from t ... | 2010 | 20967567 |
| pathogenic landscapes: interactions between land, people, disease vectors, and their animal hosts. | landscape attributes influence spatial variations in disease risk or incidence. we present a review of the key findings from eight case studies that we conducted in europe and west africa on the impact of land changes on emerging or re-emerging vector-borne diseases and/or zoonoses. the case studies concern west nile virus transmission in senegal, tick-borne encephalitis incidence in latvia, sandfly abundance in the french pyrenees, rift valley fever in the ferlo (senegal), west nile fever and t ... | 2010 | 20979609 |
| detection, isolation, and genetic characterization of rift valley fever virus from anopheles (anopheles) coustani, anopheles (anopheles) squamosus, and culex (culex) antennatus of the haute matsiatra region, madagascar. | abstract following veterinary alerts of rift valley fever (rvf) in the districts of fianarantsoa i and ii in november 2008 and in the district of ambalavao in april 2009, entomological and virological investigations were carried out to identify the mosquito species that could act as rvf virus (rvfv) vectors in the region. a total of 12,785 adult mosquitoes belonging to 5 genera and 21 species were collected. after identification, mosquitoes were pooled by species, sex, and female status (fed or ... | 2010 | 21028960 |
| reverse-phase phosphoproteome analysis of signaling pathways induced by rift valley fever virus in human small airway epithelial cells. | rift valley fever virus (rvfv) infection is an emerging zoonotic disease endemic in many countries of sub-saharan africa and in egypt. in this study we show that human small airway epithelial cells are highly susceptible to rvfv virulent strain zh-501 and the attenuated strain mp-12. we used the reverse-phase protein arrays technology to identify phosphoprotein signaling pathways modulated during infection of cultured airway epithelium. zh-501 infection induced activation of map kinases (p38, jn ... | 2010 | 21072193 |
| planning for rift valley fever virus: use of geographical information systems to estimate the human health threat of white-tailed deer (odocoileus virginianus)-related transmission. | rift valley fever (rvf) virus is a mosquito-borne phlebovirus of the bunyaviridae family that causes frequent outbreaks of severe animal and human disease in sub-saharan africa, egypt and the arabian peninsula. based on its many known competent vectors, its potential for transmission via aerosolization, and its progressive spread from east africa to neighbouring regions, rvf is considered a high-priority, emerging health threat for humans, livestock and wildlife in all parts of the world. introd ... | 2010 | 21080319 |
| rift valley fever virus infection of human cells and insect hosts is promoted by protein kinase c epsilon. | as an arthropod-borne human pathogen, rift valley fever virus (rvfv) cycles between an insect vector and mammalian hosts. little is known about the cellular requirements for infection in either host. here we developed a tissue culture model for rvfv infection of human and insect cells that is amenable to high-throughput screening. using this approach we screened a library of 1280 small molecules with pharmacologically defined activities and identified 59 drugs that inhibited rvfv infection with ... | 2010 | 21124804 |
| [assessment of the risk of introduction to tunisia of the rift valley fever virus by the mosquito culex pipiens.] | the mosquito culex pipiens has been involved as vector of the west nile virus in tunisia. its bio-ecological characteristics in combination with some environmental factors have favoured the emergence of this virus in a west-nile free zone. this leads to question about the potential risk of introducing another arbovirus, the rift valley fever (rvf) virus, in tunisia from neighbouring countries where rvf circulates. in this study, we have evaluated the vector competence of different populations of ... | 2010 | 21184293 |
| mechanism of tripartite rna genome packaging in rift valley fever virus. | the bunyaviridae family includes pathogens of medical and veterinary importance. rift valley fever virus (rvfv), a member in the phlebovirus genus of the family bunyaviridae, is endemic to sub-saharan africa and causes a mosquito-borne disease in ruminants and humans. viruses in the family bunyaviridae carry a tripartite, single-stranded, negative-sense rna genome composed of l, m, and s rnas. little is known about how the three genomic rna segments are copackaged to generate infectious bunyavir ... | 2010 | 21187405 |
| rift valley fever virus(bunyaviridae: phlebovirus): an update on pathogenesis, molecular epidemiology, vectors, diagnostics and prevention. | rift valley fever(rvf) virus is an arbovirus in the bunyaviridae family that, from phylogenetic analysis, appears to have first emerged in the mid-19th century and was only identified at the beginning of the 1930's in the rift valley region of kenya. despite being an arbovirus with a relatively simple but temporally and geographically stable genome, this zoonotic virus has already demonstrated a real capacity for emerging in new territories, as exemplified by the outbreaks in egypt (1977), weste ... | 2010 | 21188836 |
| measuring the burden of arboviral diseases: the spectrum of morbidity and mortality from four prevalent infections. | 2011 | 21219615 | |
| rift valley fever: the nigerian story. | rift valley fever (rvf) is an arthropod-borne zoonotic disease of livestock. it is characterised by fever, salivation, abdominal pain, diarrhoea, mucopurulent to bloody nasal discharge, abortion, rapid decrease in milk production and death in animals. infected humans experience an influenza-like illness that is characterised by fever, malaise, headaches, nausea and epigastric pain followed by recovery, although mortality can occur. rvf was thought to be a disease of sub-saharan africa but with t ... | 2011 | 21240849 |
| comparative production analysis of three phlebovirus nucleoproteins under denaturing or non-denaturing conditions for crystallographic studies. | nucleoproteins (nps) encapsidate the phlebovirus genomic (-)rna. upon recombinant expression, nps tend to form heterogeneous oligomers impeding characterization of the encapsidation process through crystallographic studies. to overcome this problem, we set up a standard protocol in which production under both non-denaturing and denaturing/refolding conditions can be investigated and compared. the protocol was applied for three phlebovirus nps, allowing an optimized production strategy for each o ... | 2011 | 21245924 |
| sequential rift valley fever outbreaks in eastern africa caused by multiple lineages of the virus. | during the rift valley fever (rvf) epidemic of 2006-2007 in eastern africa, spatial mapping of the outbreaks across kenya, somalia, and tanzania was performed and the rvf viruses were isolated and genetically characterized. | 2010 | 21282193 |
| potential for stable flies and house flies (diptera: muscidae) to transmit rift valley fever virus. | rift valley fever (rvf), a disease of ruminants and humans, has been responsible for large outbreaks in africa that have resulted in hundreds of thousands of human infections and major economic disruption due to loss of livestock and to trade restrictions. as indicated by the rapid spread of west nile viral activity across north america since its discovery in 1999 and the rapid and widespread movement of chikungunya virus from africa throughout the indian ocean islands to asia and europe, an int ... | 2010 | 21290943 |
| arbovirus prevalence in mosquitoes, kenya. | few studies have investigated the many mosquito species that harbor arboviruses in kenya. during the 2006-2007 rift valley fever outbreak in north eastern province, kenya, exophilic mosquitoes were collected from homesteads within 2 affected areas: gumarey (rural) and sogan-godud (urban). mosquitoes (n = 920) were pooled by trap location and tested for rift valley fever virus and west nile virus. the most common mosquitoes trapped belonged to the genus culex (75%). of 105 mosquito pools tested, ... | 2011 | 21291594 |
| [rift valley fever]. | rift valley fever (rvf) is a zoonotic arbovirosis. among animals, it mainly affects ruminants, causing abortions in gravid females and mortality among young animals. in humans, rvf virus infection is usually asymptomatic or characterized by a moderate fever. however, in 1 to 3% of cases, more severe forms of the disease (hepatitis, encephalitis, retinitis, hemorrhagic fever) can lead to the death of infected individuals or to major sequels. the rvf virus (bunyaviridae, genus phlebovirus) was ide ... | 2011 | 21295425 |
| [severe presentations of rift valley fever in madagascar]. | the authors describe clinical and epidemiologic characteristics of severe presentations of rift valley fever (rvf) during the 2008 epidemic in madagascar. | 2011 | 21295426 |
| simultaneous detection of rift valley fever, bluetongue, rinderpest, and peste des petits ruminants viruses by a single-tube multiplex reverse transcriptase-pcr assay using a dual-priming oligonucleotide system. | the aim of this study was to develop a highly sensitive and specific one-step multiplex reverse transcriptase pcr assay for the simultaneous and differential detection of rift valley fever virus (rvfv), bluetongue virus (btv), rinderpest virus (rpv), and peste des petits ruminants virus (pprv). these viruses cause mucosal lesions in cattle, sheep, and goats, and they are difficult to differentiate from one another based solely on their clinical presentation in suspected disease cases. in this st ... | 2011 | 21307219 |
| host genetic variation in susceptibility to punta toro virus. | infection of small laboratory animals by punta toro virus (ptv), family bunyaviridae, genus phlebovirus, is a model for the study of the human pathogen rift valley fever virus (rvfv). we have identified inbred mouse strains with significant differences in host response to the adames strain of ptv. nine inbred strains of mice representing major branches in the mus musculus phylogeny were inoculated subcutaneously with a high dose of ptv in survival experiments. two inbred strains of mice, nzw/lac ... | 2011 | 21320557 |
| quantitative analysis of particles, genomes and infectious particles in supernatants of haemorrhagic fever virus cell cultures. | information on the replication of viral haemorrhagic fever viruses is not readily available and has never been analysed in a comparative approach. here, we compared the cell culture growth characteristics of haemorrhagic fever viruses (hfv), of the arenaviridae, filoviridae, bunyaviridae, and flavivridae virus families by performing quantitative analysis of cell culture supernatants by (i) electron microscopy for the quantification of virus particles, (ii) quantitative real time pcr for the quan ... | 2011 | 21349180 |
| immunogenicity and safety of an inactivated rift valley fever vaccine in a 19-year study. | an investigational, formalin-inactivated rift valley fever (rvf) vaccine, known as the salk institute-government services division (tsi-gsd) 200 vaccine, was administered to 1860 at-risk subjects (5954 doses) between 1986 and 2004 as a three-dose primary series (days 0, 7, and 28) followed by booster doses as needed for declining titers. an initial positive serological response (prnt(80)=1:40) to the primary series was observed in 90% of subjects. estimate of the prnt(80) response half-life in i ... | 2011 | 21354483 |
| prevalence of rift valley fever infection in ruminants in madagascar after the 2008 outbreak. | a rift valley fever (rvf) outbreak occurred in madagascar from january to may 2008. the objectives of this study were (1) to assess the current and past circulation of rvf virus (rvfv) in livestock in madagascar and (2) to evaluate the extent and magnitude of the 2008 rvf outbreak in livestock. the results of a country-wide serosurvey conducted in august 2008 on small and large ruminants are reported here. the study included 3437 cattle and 989 small ruminants (227 sheep and 762 goats) sampled i ... | 2011 | 21395414 |
| towards a safe, effective vaccine for rift valley fever virus. | rift valley fever virus (rvfv) is an important animal and human threat and leads to longstanding morbidity and mortality in susceptible hosts. since no therapies currently exist to treat rift valley fever, it remains a public and animal health priority to develop safe, effective rvfv vaccines (whether for animals, humans, or both) that provide long-term protective immunity. in the evaluated article, bhardwaj and colleagues describe the creation and testing of two successful vaccine strategies ag ... | 2010 | 21423850 |
| efficient cellular release of rift valley fever virus requires genomic rna. | the rift valley fever virus is responsible for periodic, explosive epizootics throughout sub-saharan africa. the development of therapeutics targeting this virus is difficult due to a limited understanding of the viral replicative cycle. utilizing a virus-like particle system, we have established roles for each of the viral structural components in assembly, release, and virus infectivity. the envelope glycoprotein, gn, was discovered to be necessary and sufficient for packaging of the genome, n ... | 2011 | 21445316 |
| rift valley fever: recent insights into pathogenesis and prevention. | rift valley fever virus (rvfv) is a zoonotic pathogen that primarily affects ruminants but can also be lethal in humans. a negative-stranded rna virus of the family bunyaviridae, this pathogen is transmitted mainly via mosquito vectors. rvfv has shown the ability to inflict significant damage to livestock and is also a threat to public health. while outbreaks have traditionally occurred in sub-saharan africa, recent outbreaks in the middle east have raised awareness of the potential of this viru ... | 2011 | 21450816 |
| rift valley fever virus infection in african buffalo (syncerus caffer) herds in rural south africa: evidence of interepidemic transmission. | rift valley fever virus (rvfv) is an emerging biodefense pathogen that poses significant threats to human and livestock health. to date, the interepidemic reservoirs of rvfv are not well defined. in a longitudinal survey of infectious diseases among african buffalo during 2000-2006, 550 buffalo were tested for antibodies against rvfv in 820 capture events in 302 georeferenced locations in kruger national park, south africa. overall, 115 buffalo (21%) were seropositive. seroprevalence of rvfv was ... | 2011 | 21460024 |
| genetic evidence for rift valley fever outbreaks in madagascar resulting from virus introductions from the east african mainland rather than enzootic maintenance. | rift valley fever virus (rvfv), a mosquito-borne phlebovirus, has been detected in madagascar since 1979 with occasional outbreaks. in 2008-2009, a large rvfv outbreak was detected in malagasy livestock and humans during two successive rainy seasons. to determine whether cases were due to enzootic maintenance of virus within madagascar or importation from the east african mainland, nine rvfv whole genomic sequences were generated for viruses from the 1991 and 2008 malagasy outbreaks. bayesian co ... | 2011 | 21507967 |
| nss protein of rift valley fever virus promotes post-translational downregulation of the tfiih subunit p62. | rift valley fever virus (rvfv, family bunyaviridae, genus phlebovirus) is an important emerging pathogen of humans and ruminants. its nss protein has previously been identified as a major virulence factor that suppresses host defense through three distinct mechanisms: it directly inhibits ifn-β promoter activity, it promotes the degradation of double-stranded rna-dependent protein kinase (pkr) and it suppresses host transcription by disrupting the assembly of the basal transcription factor tfiih ... | 2011 | 21543505 |
| rift valley fever epidemiology, surveillance, and control: what have models contributed? | abstract background: rift valley fever (rvf) is an emerging vector-borne zoonotic disease that represents a threat to human health, animal health, and livestock production, particularly in africa. the epidemiology of rvf is not well understood, so that forecasting rvf outbreaks and carrying out efficient and timely control measures remains a challenge. various epidemiological modeling tools have been used to increase knowledge on rvf epidemiology and to inform disease management policies. aim: t ... | 2011 | 21548763 |
| a dna vaccine encoding ubiquitinated rift valley fever virus nucleoprotein provides consistent immunity and protects ifnar(-/-) mice upon lethal virus challenge. | current vaccine candidates against rift valley fever virus (rvfv) incorporate the viral structural glycoproteins as antigens, since triggering antibody responses against them usually correlates with protection. here, we have focused solely on the nucleoprotein of rvfv as a potential target for vaccine development. previous studies in mouse models have already demonstrated that rvfv nucleoprotein can elicit partial protection when administered by means of a dna vaccine or in recombinant, soluble, ... | 2011 | 21549790 |
| virus isolations and high population density implicate culex antennatus (becker) (diptera: culicidae) as a vector of rift valley fever virus during an outbreak in the nile delta of egypt. | in june, 2003, egypt's hospital-based electronic disease surveillance system began to record increased cases of acute febrile illness from governorates in the nile delta. in response to a request for assistance from the egyptian ministry of health and the world health organization (who), the u.s. naval medical research unit no. 3 (namru-3) provided assistance in identifying the cause and extent of this outbreak. testing of human clinical samples (n=375) from nine governorates in egypt identified ... | 2011 | 21570939 |
| the hexamer structure of the rift valley fever virus nucleoprotein suggests a mechanism for its assembly into ribonucleoprotein complexes. | rift valley fever virus (rvfv), a phlebovirus with a genome consisting of three single-stranded rna segments, is spread by infected mosquitoes and causes large viral outbreaks in africa. rvfv encodes a nucleoprotein (n) that encapsidates the viral rna. the n protein is the major component of the ribonucleoprotein complex and is also required for genomic rna replication and transcription by the viral polymerase. here we present the 1.6 å crystal structure of the rvfv n protein in hexameric form. ... | 2011 | 21589902 |
| lymphoplasmacytic endotheliitis and anterior uveitis in sheep infected experimentally with rift valley fever virus. | lymphoplasmacytic endotheliitis and anterior uveitis was diagnosed in four lambs infected experimentally with field isolates of rift valley fever virus (rvfv). formalin-fixed and paraffin wax-embedded tissue from these animals was investigated by histopathology and quantitative real time reverse transcriptase polymerase chain reaction. to our knowledge, this is the first pathological description of this ocular manifestation of rvfv infection in ruminants, although these lesions have been describ ... | 2011 | 21601870 |
| infection with a plant virus modifies vector feeding behavior. | vector infection by some animal-infecting parasites results in altered feeding that enhances transmission. modification of vector behavior is of broad adaptive significance, as parasite fitness relies on passage to a new host, and vector feeding is nearly always essential for transmission. although several plant viruses infect their insect vectors, we have shown that vector infection by a plant virus alters feeding behavior. here we show that infection with tomato spotted wilt virus (tswv), type ... | 2011 | 21606372 |
| mosquito species abundance and diversity in malindi, kenya and their potential implication in pathogen transmission. | mosquitoes (diptera: culicidae) are important vectors of human disease-causing pathogens. mosquitoes are found both in rural and urban areas. deteriorating infrastructure, poor access to health, water and sanitation services, increasing population density, and widespread poverty contribute to conditions that modify the environment, which directly influences the risk of disease within the urban and peri-urban ecosystem. the objective of this study was to evaluate the mosquito vector abundance and ... | 2011 | 21626425 |
| host alternation is necessary to maintain the genome stability of rift valley fever virus. | most arthropod-borne viruses (arboviruses) are rna viruses, which are maintained in nature by replication cycles that alternate between arthropod and vertebrate hosts. arboviruses appear to experience lower rates of evolution than rna viruses that replicate in a single host. this genetic stability is assumed to result from a fitness trade-off imposed by host alternation, which constrains arbovirus genome evolution. to test this hypothesis, we used rift valley fever virus (rvfv), an arbovirus tha ... | 2011 | 21629727 |
| parenteral vaccination of mammalian livestock with newcastle disease virus-based vector vaccines offers optimal efficacy and safety. | newcastle disease virus (ndv) is an avian virus that is being evaluated as a vaccine vector for the delivery of foreign genes in mammals. the use of ndv as a vaccine vector in these species offers two major advantages. first, ndv is highly attenuated in mammals, rendering its use inherently safe. second, mammals lack pre-existing ndv immunity, which minimizes the risk of vaccination failure. ndv-vector vaccines are generally administered to mammals via the respiratory route. we recently showed t ... | 2011 | 21636990 |
| alteration in superoxide dismutase 1 causes oxidative stress and p38 mapk activation following rvfv infection. | rift valley fever (rvf) is a zoonotic disease caused by rift valley fever virus (rvfv). rvfv is a category a pathogen that belongs to the genus phlebovirus, family bunyaviridae. understanding early host events to an infectious exposure to rvfv will be of significant use in the development of effective therapeutics that not only control pathogen multiplication, but also contribute to cell survival. in this study, we have carried out infections of human cells with a vaccine strain (mp12) and virul ... | 2011 | 21655261 |
| wicking assay for the rapid detection of rift valley fever viral antigens in mosquitoes (diptera: culicidae). | rift valley fever virus (rvfv) causes outbreaks of severe disease in domestic ungulates as well as humans in africa. there is a logical concern that rvfv could be introduced into the americas and cause significant health and economic damage based on the precedent of the introduction and spread of west nile virus (wnv). unfortunately, there are currently no licensed diagnostic assays available for rvfv in the americas. in this work, we report on the ability of a novel dipstick assay, vectortest r ... | 2011 | 21661324 |
| safety and efficacy of rift valley fever smithburn and clone 13 vaccines in calves. | two modified live attenuated vaccines against the disease rift valley fever (rvf) have been tested for safety and efficacy in young calves. the rvf smithburn vaccine produced in south africa and used successfully to prevent and control the disease in endemic sub-saharan countries was compared to the candidate vaccine rvf clone 13. five sero-negative calves per vaccine group were vaccinated with a single dose of each vaccine and tested for antibody response. all vaccinated calves were challenged ... | 2011 | 21664400 |
| the pathogenesis of rift valley fever. | rift valley fever (rvf) is an emerging zoonotic disease distributed in sub-saharan african countries and the arabian peninsula. the disease is caused by the rift valley fever virus (rvfv) of the family bunyaviridae and the genus phlebovirus. the virus is transmitted by mosquitoes, and virus replication in domestic ruminant results in high rates of mortality and abortion. rvfv infection in humans usually causes a self-limiting, acute and febrile illness; however, a small number of cases progress ... | 2011 | 21666766 |
| protection of mp-12-vaccinated rhesus macaques against parenteral and aerosol challenge with virulent rift valley fever virus. | to test safety and efficacy of the rift valley fever mp-12 (rvf mp-12) vaccine, 9 healthy adult rhesus macaques, weighing 5-10 kg, were inoculated intramuscularly with 6 × 10(3) plaque forming units (pfus) of mp-12 vaccine. the monkeys developed neutralizing antibody responses with no adverse effects other than a transient, low-titer viremia in 3 monkeys. four vaccinated animals challenged intravenously with 3 × 10(6) pfus of virulent rift valley fever virus strain zh-501 (rvfv zh-501) at 126 ... | 2011 | 21673033 |
| common, emerging, vector-borne and infrequent abortogenic virus infections of cattle. | this review deals with the aetiology and the diagnosis of bovine viral abortion. while the abortion rates on beef and dairy cattle farms usually do not exceed 10%, significant economic losses because of abortion storms may be encountered. determining the cause of abortions is usually a challenge, and it generally remains obscure in more than 50% of the necropsy submitted foetuses. bovine viral diarrhoea virus and bovine herpesvirus-1 are the most common viruses causally associated with bovine ab ... | 2011 | 21733134 |
| rift valley fever in ruminants, republic of comoros, 2009. | to the editor: rift valley fever (rvf) is caused by a phlebovirus (family bunyaviridae) transmitted by a wide range of mosquitoes (1). this zoonotic disease is present in africa, the middle east, and madagascar. infections by rvf virus (rvfv) in ruminants cause massive abortions in livestock and high death rates in young animals, which result in major economic consequences. humans are infected by mosquito bites, contact, or inhalation of aerosols. rvf is frequently unapparent or mild for humans, ... | 2011 | 21762604 |
| dc-sign as a receptor for phleboviruses. | during natural transmission, bunyaviruses are introduced into the skin through arthropod bites, and dermal dendritic cells (dcs) are the first to encounter incoming viruses. dc-sign is a c-type lectin highly expressed on the surface of dermal dcs. we found that several arthropod-borne phleboviruses (bunyaviridae), including rift valley fever and uukuniemi viruses, exploit dc-sign to infect dcs and other dc-sign-expressing cells. dc-sign binds the virus directly via interactions with high-mannose ... | 2011 | 21767814 |
| arbovirus vaccines; opportunities for the baculovirus-insect cell expression system. | the baculovirus-insect cell expression system is a well-established technology for the production of heterologous viral (glyco)proteins in cultured cells, applicable for basic scientific research as well as for the development and production of vaccines and diagnostics. arboviruses form an emerging group of medically important viral pathogens that are transmitted to humans and animals via arthropod vectors, mostly mosquitoes, ticks or midges. few arboviral vaccines are currently available, but t ... | 2011 | 21784227 |
| outbreak of rift valley fever affecting veterinarians and farmers in south africa, 2008. | during 2008, rift valley fever (rvf) virus re-emerged in south africa as focal outbreaks in several provinces. | 2011 | 21786732 |
| mucosal immunization of rhesus macaques with rift valley fever mp-12 vaccine. | rhesus macaques given 5 × 10(4) or 1 × 10(5) plaque-forming units (pfu) of rift valley fever (rvf) mp-12 vaccine by oral, intranasal drops, or small particle aerosol showed no adverse effects up to 56 days after administration. all monkeys given the vaccine by aerosol or intranasal drops developed 80% plaque reduction neutralization titers of = 1:40 by day 21 after inoculation. only 2 of 4 monkeys given the vaccine by oral instillation developed detectable neutralizing antibodies. all monkeys va ... | 2011 | 21791664 |
| creation of a recombinant rift valley fever virus with a two-segmented genome. | rift valley fever virus (rvfv; family bunyaviridae) is a clinically important, mosquito-borne pathogen of both livestock and humans, which is found mainly in sub-saharan africa and the arabian peninsula. rvfv has a tri-segmented ssrna genome. the l and m segments are negative-sense and encode the l protein (viral polymerase) on the l segment, and the virion glycoproteins gn and gc as well as two other proteins, nsm and 78k, on the m segment. the s segment uses an ambisense coding strategy to exp ... | 2011 | 21795328 |
| potential effects of rift valley fever in the united states. | rift valley fever virus (rvfv) has been the cause of disease outbreaks throughout africa and the arabian peninsula, and the infection often results in heavy economic costs through loss of livestock. if rvfv, which is common to select agent lists of the us department of health and human services and the us department of agriculture, entered the united states, either by accidental or purposeful means, the effects could be substantial. a group of subject matter experts met in december 2009 to discu ... | 2011 | 21801607 |
| validation of an igm antibody capture elisa based on a recombinant nucleoprotein for identification of domestic ruminants infected with rift valley fever virus. | the presence of competent vectors in some countries currently free of rift valley fever (rvf) and global changes in climate, travel and trade have increased the risk of rvf spreading to new regions and have emphasised the need for accurate and reliable diagnostic tools for early diagnosis during rvf outbreaks. highly sensitive viral detection systems like pcr have a limited use during outbreaks because of the short duration of viraemia, whereas antibodies like specific igm which are serological ... | 2011 | 21827790 |
| postepidemic analysis of rift valley fever virus transmission in northeastern kenya: a village cohort study. | in endemic areas, rift valley fever virus (rvfv) is a significant threat to both human and animal health. goals of this study were to measure human anti-rvfv seroprevalence in a high-risk area following the 2006-2007 kenyan rift valley fever (rvf) epidemic, to identify risk factors for interval seroconversion, and to monitor individuals previously exposed to rvfv in order to document the persistence of their anti-rvfv antibodies. | 2011 | 21858236 |
| Recent advances in the molecular and cellular biology of bunyaviruses. | The family Bunyaviridae of segmented, negative-stranded RNA viruses includes over 350 members that infect a bewildering variety of animals and plants. Many of these bunyaviruses are the causative agents of serious disease in their respective hosts, and are classified as emerging viruses because of their increased incidence in new populations and geographical locations throughout the world. Emerging bunyaviruses, such as Crimean-Congo hemorrhagic fever virus, tomato spotted wilt virus and Rift Va ... | 2011 | 21865443 |
| recombinant rift valley fever vaccines induce protective levels of antibody in baboons and resistance to lethal challenge in mice. | rift valley fever (rvf) is a zoonotic disease endemic in africa and the arabian peninsula caused by the highly infectious rift valley fever virus (rvfv) that can be lethal to humans and animals and results in major losses in the livestock industry. rvf is exotic to the united states; however, mosquito species native to this region can serve as biological vectors for the virus. thus, accidental or malicious introduction of this virus could result in rvfv becoming endemic in north america. such an ... | 2011 | 21873194 |
| Generation and characterization of a recombinant Rift Valley fever virus expressing a V5 epitope-tagged RNA-dependent RNA polymerase. | The viral RNA-dependent RNA polymerase (RdRp; L protein) of Rift Valley fever virus (RVFV; family Bunyaviridae) is a 238 kDa protein that is crucial for the life cycle of the virus, as it catalyses both transcription of viral mRNAs and replication of the tripartite genome. Despite its importance, little is known about the intracellular distribution of the polymerase or its other roles during infection, primarily because of lack of specific antibodies that recognize L protein. To begin to address ... | 2011 | 21900422 |
| Characterization of wild-type and alternate transcription termination signals in the Rift Valley fever virus genome. | Rift Valley fever (RVF) is a mosquito-borne zoonotic disease caused by a phlebovirus of the family Bunyaviridae, which affects humans and ruminants in Africa and the Middle East. RFV virus (RVFV) possesses a single-stranded tripartite RNA genome of negative/ambisense polarity. The S segment utilizes the ambisense strategy and codes for two proteins, the N nucleoprotein and the nonstructural NSs protein, in opposite orientations. The two open reading frames (ORFs) are separated by an intergenic r ... | 2011 | 21917943 |
| the status of rift valley fever in animals in saudi arabia: a mini review. | in august-september 2000, an overwhelming outbreak of rift valley fever (rvf) struck the southwestern part of saudi arabia and adjoining yemeni territories. during the outbreak, which was the first ever to be recorded outside africa, around 40,000 animals, mostly sheep and goats, died or aborted and 883 cases, with 124 deaths, were recorded among humans in saudi arabia. an additional 1328 human cases, with 166 deaths, were concurrently recorded in northwestern yemen. vector studies in saudi arab ... | 2011 | 21923257 |
| detection of puumala and rift valley fever virus by quantitative rt-pcr and virus viability tests in samples of blood dried and stored on filter paper. | haemorrhagic fever viruses cause emerging infections worldwide, and blood or serum is the main sample used for diagnosis. however, storage and transportation of such samples from remote areas to regional laboratories may be complicated and expensive. in this study, a novel approach was evaluated for the detection of puumala hantavirus (puuv) rna and rift valley fever virus (rvfv) rna. whole-blood samples spiked with viable virus particles were tested in parallel with clinical samples from patien ... | 2011 | 21946288 |