evaluation of the efficacy, potential for vector transmission, and duration of immunity of mp-12, an attenuated rift valley fever virus vaccine candidate, in sheep.rift valley fever virus (rvfv) causes serious disease in ruminants and humans in africa. in north america, there are susceptible ruminant hosts and competent mosquito vectors, yet there are no fully licensed animal vaccines for this arthropod-borne virus, should it be introduced. studies in sheep and cattle have found the attenuated strain of rvfv, mp-12, to be both safe and efficacious based on early testing, and a 2-year conditional license for use in u.s. livestock has been issued. the purpos ...201526041042
biologically informed individual-based network model for rift valley fever in the us and evaluation of mitigation strategies.rift valley fever (rvf) is a zoonotic disease endemic in sub-saharan africa with periodic outbreaks in human and animal populations. mosquitoes are the primary disease vectors; however, rift valley fever virus (rvfv) can also spread by direct contact with infected tissues. the transmission cycle is complex, involving humans, livestock, and multiple species of mosquitoes. the epidemiology of rvfv in endemic areas is strongly affected by climatic conditions and environmental variables. in this res ...201627662585
metagenomic shotgun sequencing of a bunyavirus in wild-caught aedes aegypti from thailand informs the evolutionary and genomic history of the phleboviruses.arthropod-borne viruses significantly impact human health. they span multiple families, all of which include viruses not known to cause disease. characterizing these representatives could provide insights into the origins of their disease-causing counterparts. field-caught aedes aegypti mosquitoes from nakhon nayok, thailand, underwent metagenomic shotgun sequencing to reveal a bunyavirus closely related to phasi charoen (phav) virus, isolated in 2009 from ae. aegypti near bangkok. phylogenetic ...201425108381
rift valley fever virus nss protein functions and the similarity to other bunyavirus nss proteins.rift valley fever is a mosquito-borne zoonotic disease that affects both ruminants and humans. the nonstructural (ns) protein, which is a major virulence factor for rift valley fever virus (rvfv), is encoded on the s-segment. through the cullin 1-skp1-fbox e3 ligase complex, the nss protein promotes the degradation of at least two host proteins, the tfiih p62 and the pkr proteins. nss protein bridges the fbox protein with subsequent substrates, and facilitates the transfer of ubiquitin. the sap3 ...201627368371
phleboviruses and the type i interferon response.the genus phlebovirus of the family bunyaviridae contains a number of emerging virus species which pose a threat to both human and animal health. most prominent members include rift valley fever virus (rvfv), sandfly fever naples virus (sfnv), sandfly fever sicilian virus (sfsv), toscana virus (tosv), punta toro virus (ptv), and the two new members severe fever with thrombocytopenia syndrome virus (sftsv) and heartland virus (hrtv). the nonstructural protein nss is well established as the main p ...201627338447
emerging phleboviruses.the bunyavidae family is the largest grouping of rna viruses and arguably the most diverse. bunyaviruses have a truly global distribution and can infect vertebrates, invertebrates and plants. the majority of bunyaviruses are vectored by arthropods and thus have the remarkable capability to replicate in hosts of disparate phylogeny. the family has provided many examples of emerging viruses including sin nombre and related viruses responsible for hantavirus cardiopulmonary syndrome in the americas ...201424607799
complete genome sequence of two rift valley fever virus strains isolated from outbreaks in saudi arabia (2000) and kenya (2006 to 2007).the complete genome sequence, including the untranslated regions, of two rift valley fever virus (rvfv) strains isolated from mosquitoes that were collected from disease outbreaks in saudi arabia (2001) and kenya (2006 to 2007) were sequenced using next-generation sequencing technology.201627609913
experimental infection of calves by two genetically-distinct strains of rift valley fever virus.recent outbreaks of rift valley fever in ruminant livestock, characterized by mass abortion and high mortality rates in neonates, have raised international interest in improving vaccine control strategies. previously, we developed a reliable challenge model for sheep that improves the evaluation of existing and novel vaccines in sheep. this sheep model demonstrated differences in the pathogenesis of rift valley fever virus (rvfv) infection between two genetically-distinct wild-type strains of th ...201627223298
distribution and diversity of the vectors of rift valley fever along the livestock movement routes in the northeastern and coastal regions of kenya.knowledge of vector ecology is important in understanding the transmission dynamics of vector borne disease. in this study, we determined the distribution and diversity of mosquitoes along the major nomadic livestock movement routes (lmr) in the traditional pastoral ecozone of northeastern kenya. we focused on the vectors of rift valley fever virus (rvfv) with the aim of understanding their ecology and how they can potentially influence the circulation of rvfv.201526018134
inter-epidemic abundance and distribution of potential mosquito vectors for rift valley fever virus in ngorongoro district, tanzania.rift valley fever (rvf) is a mosquito-borne viral zoonosis that primarily affects ruminants but also has the capacity to infect humans.201525613346
predicting rift valley fever inter-epidemic activities and outbreak patterns: insights from a stochastic host-vector model.rift valley fever (rvf) outbreaks are recurrent, occurring at irregular intervals of up to 15 years at least in east africa. between outbreaks disease inter-epidemic activities exist and occur at low levels and are maintained by female aedes mcintoshi mosquitoes which transmit the virus to their eggs leading to disease persistence during unfavourable seasons. here we formulate and analyse a full stochastic host-vector model with two routes of transmission: vertical and horizontal. by applying br ...201628002417
cytokine response in mouse bone marrow derived macrophages after infection with pathogenic and non-pathogenic rift valley fever virus.rift valley fever virus (rvfv) is the most pathogenic member of the genus phlebovirus within the family bunyaviridae, and can cause severe disease in humans and livestock. until recently, limited information has been published on the cellular host response elicited by rvfv, particularly in macrophages and dendritic cells, which play critical roles in stimulating adaptive and innate immune responses to viral infection. in an effort to define the initial response of host immunomodulatory cells to ...201525759029
population genetics of two key mosquito vectors of rift valley fever virus reveals new insights into the changing disease outbreak patterns in kenya.rift valley fever (rvf) outbreaks in kenya have increased in frequency and range to include northeastern kenya where viruses are increasingly being isolated from known (aedes mcintoshi) and newly-associated (ae. ochraceus) vectors. the factors contributing to these changing outbreak patterns are unclear and the population genetic structure of key vectors and/or specific virus-vector associations, in particular, are under-studied. by conducting mitochondrial and nuclear dna analyses on >220 kenya ...201425474018
predicting distribution of aedes aegypti and culex pipiens complex, potential vectors of rift valley fever virus in relation to disease epidemics in east africa.the east african region has experienced several rift valley fever (rvf) outbreaks since the 1930s. the objective of this study was to identify distributions of potential disease vectors in relation to disease epidemics. understanding disease vector potential distributions is a major concern for disease transmission dynamics.201324137533
molecular biology and genetic diversity of rift valley fever virus.rift valley fever virus (rvfv), a member of the family bunyaviridae, genus phlebovirus, is the causative agent of rift valley fever (rvf), a mosquito-borne disease of ruminant animals and humans. the generation of a large sequence database has facilitated studies of the evolution and spread of the virus. bayesian analyses indicate that currently circulating strains of rvfv are descended from an ancestral species that emerged from a natural reservoir in africa when large-scale cattle and sheep fa ...201222710362
chemotactic and inflammatory responses in the liver and brain are associated with pathogenesis of rift valley fever virus infection in the mouse.rift valley fever virus (rvfv) is a major human and animal pathogen associated with severe disease including hemorrhagic fever or encephalitis. rvfv is endemic to parts of africa and the arabian peninsula, but there is significant concern regarding its introduction into non-endemic regions and the potentially devastating effect to livestock populations with concurrent infections of humans. to date, there is little detailed data directly comparing the host response to infection with wild-type or ...201222389738
rift valley fever virus circulating among ruminants, mosquitoes and humans in the central african republic.rift valley fever virus (rvfv) causes a viral zoonosis, with discontinuous epizootics and sporadic epidemics, essentially in east africa. infection with this virus causes severe illness and abortion in sheep, goats, and cattle as well as other domestic animals. humans can also be exposed through close contact with infectious tissues or by bites from infected mosquitoes, primarily of the aedes and culex genuses. although the cycle of rvfv infection in savannah regions is well documented, its dist ...201627760144
genome analysis of rift valley fever virus, further confirmation of a first human case of rift valley fever in 2007 in comoros, we isolated rift valley fever virus in suspected human cases. these viruses are genetically closely linked to the 2006-2007 isolates from kenya.022608405
inter-epidemic transmission of rift valley fever in livestock in the kilombero river valley, tanzania: a cross-sectional recent years, evidence of rift valley fever (rvf) transmission during inter-epidemic periods in parts of africa has increasingly been reported. the inter-epidemic transmissions generally pass undetected where there is no surveillance in the livestock or human populations. we studied the presence of and the determinants for inter-epidemic rvf transmission in an area experiencing annual flooding in southern tanzania.201323951376
vector competence of aedes vexans (meigen), culex poicilipes (theobald) and cx. quinquefasciatus say from senegal for west and east african lineages of rift valley fever virus.rift valley fever virus (rvfv; phlebovirus, bunyaviridae) is a mosquito-borne, zoonotic pathogen. in senegal, rvfv was first isolated in 1974 from aedes dalzieli (theobald) and thereafter from ae. fowleri (de charmoy), ae. ochraceus theobald, ae. vexans (meigen), culex poicilipes (theobald), mansonia africana (theobald) and ma. uniformis (theobald). however, the vector competence of these local species has never been demonstrated making hypothetical the transmission cycle proposed for west afric ...201626897521
the rift valley fever accessory proteins nsm and p78/nsm-gn are distinct determinants of virus propagation in vertebrate and invertebrate hosts.rift valley fever virus (rvfv) is an enzootic virus circulating in africa that is transmitted to its vertebrate host by a mosquito vector and causes severe clinical manifestations in humans and ruminants. rvfv has a tripartite genome of negative or ambisense polarity. the m segment contains five in-frame aug codons that are alternatively used for the synthesis of two major structural glycoproteins, gn and gc, and at least two accessory proteins, nsm, a 14-kda cytosolic protein, and p78/nsm-gn, a ...201426038497
countermeasure development for rift valley fever: deletion, modification or targeting of major virulence factor nss.rift valley fever (rvf) is a mosquito-borne zoonotic disease characterized by a high rate of abortion in ruminants, and febrile illness, hemorrhagic fever, retinitis and encephalitis in humans. rvf is caused by the rvf virus (rvfv), belonging to the genus phlebovirus of the family bunyaviridae. rvfv encodes a major virulence factor, nss, which is dispensable for viral replication, yet required for evasion of host innate immune responses. rvfv nss inhibits host gene upregulation at the transcript ...024910709
the consequences of reconfiguring the ambisense s genome segment of rift valley fever virus on viral replication in mammalian and mosquito cells and for genome packaging.rift valley fever virus (rvfv, family bunyaviridae) is a mosquito-borne pathogen of both livestock and humans, found primarily in sub-saharan africa and the arabian peninsula. the viral genome comprises two negative-sense (l and m segments) and one ambisense (s segment) rnas that encode seven proteins. the s segment encodes the nucleocapsid (n) protein in the negative-sense and a nonstructural (nss) protein in the positive-sense, though nss cannot be translated directly from the s segment but ra ...201424550727
deletion of the nsm virulence gene of rift valley fever virus inhibits virus replication in and dissemination from the midgut of aedes aegypti mosquitoes.previously, we investigated the role of the rift valley fever virus (rvfv) virulence genes nss and nsm in mosquitoes and demonstrated that deletion of nsm significantly reduced the infection, dissemination, and transmission rates of rvfv in aedes aegypti mosquitoes. the specific aim of this study was to further characterize midgut infection and escape barriers of rvfv in ae. aegypti infected with reverse genetics-generated wild type rvfv (rrvf-wt) or rvfv lacking the nsm virulence gene (rrvf-δns ...201424551252
characterization of rift valley fever virus mp-12 strain encoding nss of punta toro virus or sandfly fever sicilian virus.rift valley fever virus (rvfv; genus phlebovirus, family bunyaviridae) is a mosquito-borne zoonotic pathogen which can cause hemorrhagic fever, neurological disorders or blindness in humans, and a high rate of abortion in ruminants. mp-12 strain, a live-attenuated candidate vaccine, is attenuated in the m- and l-segments, but the s-segment retains the virulent phenotype. mp-12 was manufactured as an investigational new drug vaccine by using mrc-5 cells and encodes a functional nss gene, the majo ...201323638202
rna encapsidation and packaging in the phleboviruses.the bunyaviridae represents the largest family of segmented rna viruses, which infect a staggering diversity of plants, animals, and insects. within the family bunyaviridae, the phlebovirus genus includes several important human and animal pathogens, including rift valley fever virus (rvfv), severe fever with thrombocytopenia syndrome virus (sftsv), uukuniemi virus (uukv), and the sandfly fever viruses. the phleboviruses have small tripartite rna genomes that encode a repertoire of 5-7 proteins. ...201627428993
infection and transmission of rift valley fever viruses lacking the nss and/or nsm genes in mosquitoes: potential role for nsm in mosquito infection.rift valley fever virus is an arthropod-borne human and animal pathogen responsible for large outbreaks of acute and febrile illness throughout africa and the arabian peninsula. reverse genetics technology has been used to develop deletion mutants of the virus that lack the nss and/or nsm virulence genes and have been shown to be stable, immunogenic and protective against rift valley fever virus infection in animals. we assessed the potential for these deletion mutant viruses to infect and be tr ...201222563517
high seroprevalence of rift valley fever and evidence for endemic circulation in mbeya region, tanzania, in a cross-sectional study.the rift valley fever virus (rvfv) is an arthropod-borne phlebovirus. rvfv mostly causes outbreaks among domestic ruminants with a major economic impact. human infections are associated with these events, with a fatality rate of 0.5-2%. since the virus is able to use many mosquito species of temperate climates as vectors, it has a high potential to spread to outside africa.201222479657
seroprevalence of antibodies against chikungunya, dengue, and rift valley fever viruses after febrile illness outbreak, october 2009, two-3 months after an outbreak of a febrile disease with joint pain on the eastern coast of madagascar, we assessed serologic markers for chikungunya virus (chikv), dengue virus (denv), and rift valley fever virus (rvfv) in 1,244 pregnant women at 6 locations. in 2 eastern coast towns, igg seroprevalence against chikv was 45% and 23%; igm seroprevalence was 28% and 5%. igg seroprevalence against denv was 17% and 11%. no anti-denv igm was detected. at 4 locations, 450-1,300 m hig ...023092548
the c-terminal region of rift valley fever virus nsm protein targets the protein to the mitochondrial outer membrane and exerts antiapoptotic function.the nsm nonstructural protein of rift valley fever virus (family bunyaviridae, genus phlebovirus) has an antiapoptotic function and affects viral pathogenesis. we found that nsm integrates into the mitochondrial outer membrane and that the protein's n terminus is exposed to the cytoplasm. the c-terminal region of nsm, which contains a basic amino acid cluster and a putative transmembrane domain, targeted the protein to the mitochondrial outer membrane and exerted antiapoptotic function.201223097454
non-structural proteins of arthropod-borne bunyaviruses: roles and functions.viruses within the bunyaviridae family are tri-segmented, negative-stranded rna viruses. the family includes several emerging and re-emerging viruses of humans, animals and plants, such as rift valley fever virus, crimean-congo hemorrhagic fever virus, la crosse virus, schmallenberg virus and tomato spotted wilt virus. many bunyaviruses are arthropod-borne, so-called arboviruses. depending on the genus, bunyaviruses encode, in addition to the rna-dependent rna polymerase and the different struct ...201324100888
a recombinant rift valley fever virus glycoprotein subunit vaccine confers full protection against rift valley fever challenge in sheep.rift valley fever virus (rvfv) is a mosquito-borne zoonotic pathogen causing disease outbreaks in africa and the arabian peninsula. the virus has great potential for transboundary spread due to the presence of competent vectors in non-endemic areas. there is currently no fully licensed vaccine suitable for use in livestock or humans outside endemic areas. here we report the evaluation of the efficacy of a recombinant subunit vaccine based on the rvfv gn and gc glycoproteins. in a previous study, ...201627296136
a haploid genetic screen identifies heparan sulfate proteoglycans supporting rift valley fever virus infection.rift valley fever virus (rvfv) causes recurrent insect-borne epizootics throughout the african continent, and infection of humans can lead to a lethal hemorrhagic fever syndrome. deep mutagenesis of haploid human cells was used to identify host factors required for rvfv infection. this screen identified a suite of enzymes involved in glycosaminoglycan (gag) biogenesis and transport, including several components of the cis-oligomeric golgi (cog) complex, one of the central components of golgi com ...201526581979
creation of rift valley fever viruses with four-segmented genomes reveals flexibility in bunyavirus genome packaging.bunyavirus genomes comprise a small (s), a medium (m), and a large (l) rna segment of negative polarity. although the untranslated regions have been shown to comprise signals required for transcription, replication, and encapsidation, the mechanisms that drive the packaging of at least one s, m, and l segment into a single virion to generate infectious virus are largely unknown. one of the most important members of the bunyaviridae family that causes devastating disease in ruminants and occasion ...201425008937
ngari virus in goats during rift valley fever outbreak, mauritania, 2010. 025419696
rift valley fever virus mp-12 vaccine is fully attenuated by a combination of partial attenuations in the s, m, and l segments.rift valley fever (rvf) is a mosquito-borne zoonotic disease endemic to africa and characterized by a high rate of abortion in ruminants and hemorrhagic fever, encephalitis, or blindness in humans. rvf is caused by rift valley fever virus (rvfv; family bunyaviridae, genus phlebovirus), which has a tripartite negative-stranded rna genome (consisting of the s, m, and l segments). further spread of rvf into countries where the disease is not endemic may affect the economy and public health, and vac ...201525948740
the transmission potential of rift valley fever virus among livestock in the netherlands: a modelling study.rift valley fever virus (rvfv) is a zoonotic vector-borne infection and causes a potentially severe disease. many mammals are susceptible to infection including important livestock species. although currently confined to africa and the near-east, this disease causes concern in countries in temperate climates where both hosts and potential vectors are present, such as the netherlands. currently, an assessment of the probability of an outbreak occurring in this country is missing. to evaluate the ...201323876054
identifying landscape features associated with rift valley fever virus transmission, ferlo region, senegal, using very high spatial resolution satellite imagery.dynamics of most of vector-borne diseases are strongly linked to global and local environmental changes. landscape changes are indicators of human activities or natural processes that are likely to modify the ecology of the diseases. here, a landscape approach developed at a local scale is proposed for extracting mosquito favourable biotopes, and for testing ecological parameters when identifying risk areas of rift valley fever (rvf) transmission. the study was carried out around barkedji villag ...201323452759
combining hydrology and mosquito population models to identify the drivers of rift valley fever emergence in semi-arid regions of west africa.rift valley fever (rvf) is a vector-borne viral zoonosis of increasing global importance. rvf virus (rvfv) is transmitted either through exposure to infected animals or through bites from different species of infected mosquitoes, mainly of aedes and culex genera. these mosquitoes are very sensitive to environmental conditions, which may determine their presence, biology, and abundance. in east africa, rvf outbreaks are known to be closely associated with heavy rainfall events, unlike in the semi ...201222928055
inter-epidemic acquisition of rift valley fever virus in humans in east africa, epidemics of rift valley fever (rvf) occur in cycles of 5-15 years following unusually high rainfall. rvf transmission during inter-epidemic periods (iep) generally passes undetected in absence of surveillance in mammalian hosts and vectors. we studied iep transmission of rvf and evaluated the demographic, behavioural, occupational and spatial determinants of past rvf infection.201525723502
aerosol exposure to rift valley fever virus causes earlier and more severe neuropathology in the murine model, which has important implications for therapeutic development.rift valley fever virus (rvfv) is an important mosquito-borne veterinary and human pathogen that can cause severe disease including acute-onset hepatitis, delayed-onset encephalitis, retinitis and blindness, or a hemorrhagic syndrome. currently, no licensed vaccine or therapeutics exist to treat this potentially deadly disease. detailed studies describing the pathogenesis of rvfv following aerosol exposure have not been completed and candidate therapeutics have not been evaluated following an ae ...201323593523
phylogeography of rift valley fever virus in africa and the arabian peninsula.rift valley fever is an acute zoonotic viral disease caused by rift valley fever virus (rvfv) that affects ruminants and humans in sub-saharan africa and the arabian peninsula. we used phylogenetic analyses to understand the demographic history of rvfv populations, using sequence data from the three minigenomic segments of the virus. we used phylogeographic approaches to infer rvfv historical movement patterns across its geographic range, and to reconstruct transitions among host species. result ...201728068340
seroprevalence of sheep and goat pox, peste des petits ruminants and rift valley fever in saudi arabia.sheep and goat pox, peste des petits ruminants and rift valley fever are important diseases of small ruminant livestock. sheep and goat pox, along with peste des petits ruminants, are endemic throughout most of africa, asia and the middle east. whereas rift valley fever is endemic in africa, outbreaks in the middle east have been reported over the past decade, including the arabian peninsula. saudi arabia is a major importer of livestock, and understanding the prevalence of these viral infection ...201526462199
correlative gene expression to protective seroconversion in rift valley fever vaccinates.rift valley fever virus (rvfv), a negative-stranded rna virus, is the etiological agent of the vector-borne zoonotic disease, rift valley fever (rvf). in both humans and livestock, protective immunity can be achieved through vaccination. earlier and more recent vaccine trials in cattle and sheep demonstrated a strong neutralizing antibody and total igg response induced by the rvf vaccine, authentic recombinant mp-12 (armp-12). from previous work, protective immunity in sheep and cattle vaccinate ...201626783758
immunogenicity of a recombinant rift valley fever mp-12-nsm deletion vaccine candidate in calves.the safety and immunogenicity of an authentic recombinant (ar) of the live, attenuated mp-12 rift valley fever (rvf) vaccine virus with a large deletion of the nsm gene in the pre-gn region of the m rna segment (armp-12δnsm21/384) was tested in 4-6 month old bos taurus calves. phase i of this study evaluated the neutralizing antibody response, measured by 80% plaque reduction neutralization (prnt80), and clinical response of calves to doses of 1 × 10(1) through 1 × 10(7) plaque forming units (pf ...201323994375
geographic range of vector-borne infections and their vectors: the role of african wildlife.the role of african wildlife in the occurrence of vector-borne infections in domestic animals has gained renewed interest as emerging and re-emerging infections occur worldwide at an increasing rate. in africa, biodiversity conservation and the expansion of livestock production have increased the risk of transmitting vector-borne infections between wildlife and livestock. the indigenous african pathogens with transboundary potential, such as rift valley fever virus, african horse sickness virus, ...201526470454
companion animals as a source of viruses for human beings and food production animals.companion animals comprise a wide variety of species, including dogs, cats, horses, ferrets, guinea pigs, reptiles, birds and ornamental fish, as well as food production animal species, such as domestic pigs, kept as companion animals. despite their prominent place in human society, little is known about the role of companion animals as sources of viruses for people and food production animals. therefore, we reviewed the literature for accounts of infections of companion animals by zoonotic viru ...201627522300
arboviruses pathogenic for domestic and wild animals.the objective of this chapter is to provide an updated and concise systematic review on taxonomy, history, arthropod vectors, vertebrate hosts, animal disease, and geographic distribution of all arboviruses known to date to cause disease in homeotherm (endotherm) vertebrates, except those affecting exclusively man. fifty arboviruses pathogenic for animals have been documented worldwide, belonging to seven families: togaviridae (mosquito-borne eastern, western, and venezuelan equine encephaliliti ...201424751197
generation of a recombinant akabane virus expressing enhanced green fluorescent protein.we generated a recombinant akabane virus (akav) expressing enhanced green fluorescence protein (egfp-akav) by using reverse genetics. we artificially constructed an ambisense akav s genome encoding n/nss on the negative-sense strand, and egfp on the positive-sense strand with an intergenic region (igr) derived from the rift valley fever virus (rvfv) s genome. the recombinant virus exhibited egfp fluorescence and had a cytopathic effect in cell cultures, even after several passages. these results ...201526157127
schmallenberg virus--is it present in south africa?in july 2006, a case of two out of three lambs born to one ewe in a flock of 45 had signs that, in retrospect, were possibly consistent with schmallenberg virus infection. this occurred in the onderstepoort area (gauteng province) but a definitive diagnosis was not made. then, in may 2008, a farmer in the delmas area (mpumalanga province) reported that deformed lambs had been born to several ewes in the flock. six of the approximately 50 mated ewes gave birth to lambs showing varying degrees of ...201323718876
infection and propagation of crimean-congo hemorrhagic fever virus in embryonated chicken eggs.the embryonated chicken egg (ece) provides a convenient, space-saving incubator for the cultivation of many kinds of animal viruses where the egg can be easily observed for viral replication throughout the development of the chicken embryo. within the family bunyaviridae, the embryonated egg has been used as a host system for many viruses such as rift valley fever virus and akabane virus. the current study was conducted to determine the cultivation of crimean-congo hemorrhagic fever virus (cchfv ...201323352881
simultaneous detection of igg antibodies associated with viral hemorrhagic fever by a multiplexed luminex-based immunoassay.viral hemorrhagic fevers (vhfs) are worldwide diseases caused by several kinds of viruses. with the emergence of new viruses, advanced diagnostic methods are urgently needed for identification of vhfs. based on luminex xmap technology, a rapid, sensitive, multi-pathogen and high-throughput method which could simultaneously detect hemorrhagic fever viruses (hfvs) specific igg antibodies was developed. recombinant antigens of nine hfvs including hantaan virus (htnv), seoul virus (seov), puumala vi ...201424631566
effects of climate change on the occurrence and distribution of livestock diseases.the planet's mean air and ocean temperatures have been rising over the last century because of increasing greenhouse gas (ghg) emissions. these changes have substantial effects on the epidemiology of infectious diseases. we describe direct and indirect processes linking climate change and infectious diseases in livestock with reference to specific case studies. some of the studies are used to show a positive association between temperature and expansion of the geographical ranges of arthropod ve ...201728040271
molecular and serological survey of some haemoprotozoan, rickettsial and viral diseases of small ruminants from al-madinah al munawarah, ksa.the prevalence of some viral and haemoprotozoan infections in goats and sheep was investigated in the present study. the infections of anaplasma spp. and theileria spp. were encountered by pcr and celisa for the detection of anaplasma spp. anaplasma spp. was more prevalent than theileria spp. with a significant difference (pvalue<0.05) in both goats and sheep, but, the infection in sheep was more prevalent than goats. also four viral infections were detected: rift valley fever virus (rvfv), blue ...201526695213
simultaneous detection of five notifiable viral diseases of cattle by single-tube multiplex real-time rt-pcr.multiplexed real-time pcr (qpcr) assays enable the detection of several target genes in a single reaction, which is applicable for simultaneous testing for the most important viral diseases in samples obtained from ruminants with unspecific clinical symptoms. here, reverse transcription qpcr (rt-qpcr) systems for the detection of bovine viral diarrhoea virus (bvdv) and bluetongue virus (btv) were combined with an internal control system based on the beta-actin gene. additionally, a background sc ...201525746154
detection in and circulation of bluetongue virus among domestic ruminants in far, no published data was available concerning the circulation of bluetongue virus (btv) in madagascar. during a survey on rift valley fever, we were able to detect a virus belonging to btv. therefore, we conducted a study aiming at characterizing molecularly the btv isolated and assess the importance of circulation of btv in madagascar. a total of 4393 sera from ruminants selected randomly by stratification and sampled in 30 districts of madagascar were tested for btv. moreover, 175 cattle ...201525736861
using animal performance data to evidence the under-reporting of case herds during an epizootic: application to an outbreak of bluetongue in cattle.following the emergence of the bluetongue virus serotype 8 (btv-8) in france in 2006, a surveillance system (both passive and active) was implemented to detect and follow precociously the progression of the epizootic wave. this system did not allow a precise estimation of the extent of the epizootic. infection by btv-8 is associated with a decrease of fertility. the objective of this study was to evaluate whether a decrease in fertility can be used to evidence the under-reporting of cases during ...201424937630
a transversal study on antibodies against selected pathogens in dromedary camels in the canary islands, spain.the canary islands contain the most important dromedary camel (camelus dromedarius) population in the european union and are the main export point of dromedaries to continental europe and latin america. we investigated the presence of antibodies against relevant disease agents in 100 canarian camel sera. selected blood samples of the same animals were also tested by pcr. sera were tested for antibodies against bluetongue virus (btv; 0%), bovine viral diarrhoea virus (bvdv; 0%), camelpox virus (c ...201323992795
phylogenetic analysis of bunyamwera and ngari viruses (family bunyaviridae, genus orthobunyavirus) isolated in kenya.orthobunyaviruses, tri-segmented, negative-sense rna viruses, have long been associated with mild to severe human disease in africa, but not haemorrhagic fever. however, during a rift valley fever outbreak in east africa in 1997-1998, ngari virus was isolated from two patients and antibody detected in several others with haemorrhagic fever. the isolates were used to identify ngari virus as a natural orthobunyavirus reassortant. despite their potential to reassort and cause severe human disease, ...201626118981
bunyamwera virus possesses a distinct nucleocapsid protein to facilitate genome encapsidation.bunyamwera virus (bunv), which belongs to the genus orthobunyavirus, is the prototypical virus of the bunyaviridae family. similar to other negative-sense single-stranded rna viruses, bunyaviruses possess a nucleocapsid protein (np) to facilitate genomic rna encapsidation and virus replication. the structures of two nps of members of different genera within the bunyaviridae family have been reported. however, their structures, rna-binding features, and functions beyond rna binding significantly ...201323569257
laboratory validation of the sand fly fever virus antigen assay.sandfly fever group viruses in the genus phlebovirus (family bunyaviridae) are widely distributed across the globe and are a cause of disease in military troops and indigenous peoples. we assessed the laboratory sensitivity and specificity of the sand fly fever virus antigen assay, a rapid dipstick assay designed to detect sandfly fever naples virus (sfnv) and toscana virus (tosv) against a panel of phleboviruses. the assay detected sfnv and tosv, as well as other phleboviruses including aguacat ...201526675463
neuropathological microscopic features of abortions induced by bunyavirus / or flavivirus infections.the present study describes the pathologic changes in the brain and the spinal cord of aborted, stillbirth and deformities of newborn lambs infected with viral agents.201425425524
quantifying the potential pathways and locations of rift valley fever virus entry into the united states.the global invasion of west nile virus, chikungunya virus and zika virus in the past two decades suggests an increasing rate of mosquito-borne virus (arbovirus) dispersal. rift valley fever virus (rvfv) is an arbovirus identified as a high-consequence threat to the united states (usa) because of the severe economic and health consequences associated with disease. numerous studies demonstrate that the usa is receptive to rvfv transmission based on the widespread presence of competent mosquito spe ...201728191786
seroconversion to causes of febrile illness in mongolian peacekeepers deployed to south sudan.immediately before deployment (fall 2012) and after deployment (spring 2013) in support of united nations peacekeeping operations, mongolian armed forces medical personnel obtained serum samples from the first contingent of mongolian peacekeepers deploying to south sudan to monitor serologic evidence of exposure to diseases that cause acute febrile illness. a total of 632 paired samples were tested for igg antibody for the following (number of seroconversions in parentheses): rickettsia (spotted ...201627928094
association of rift valley fever virus infection with miscarriage in sudanese women: a cross-sectional study.rift valley fever virus is an emerging mosquito-borne virus that causes infections in animals and human beings in africa and the arabian peninsula. outbreaks of rift valley fever lead to mass abortions in livestock, but such abortions have not been identified in human beings. our aim was to investigate the cause of miscarriages in febrile pregnant women in an area endemic for rift valley fever.201627692776
[the mosquito-borne viruses in europe].epidemiologic changes of vector-borne diseases in recent years have multiple causes, including climate change. there are about 3500 species of mosquitoes worldwide, three-quarters of which live in tropical and subtropical wetlands. main viruses transmitted by mosquitoes in europe belong to the genus flavivirus; some of them have been recently reported in italy (usutu and japanese encephalitis virus), while others have been circulating for years and autochthonous transmission has been documented ...201525805223
[the mosquito-borne viruses in europe].epidemiologic changes of vector-borne diseases in recent years have multiple causes, including climate change. there are about 3500 species of mosquitoes worldwide, three-quarters of which live in tropical and subtropical wetlands. main viruses transmitted by mosquitoes in europe belong to the genus flavivirus; some of them have been recently reported in italy (usutu and japanese encephalitis virus), while others have been circulating for years and autochthonous transmission has been documented ...201525805223
high-content image-based screening of a signal transduction pathway inhibitor small-molecule library against highly pathogenic rna viruses.high-content image-based screening was developed as an approach to test a small-molecule library of compounds targeting signal transduction pathways for antiviral activity against multiple highly pathogenic rna viruses. of the 2843 compounds screened, 120 compounds exhibited ≥60% antiviral activity. four compounds (e225-0969, e528-0039, g118-0778, and g544-0735), which were most active against rift valley fever virus (rvfv) and showed broad-spectrum antiviral activity, were selected for further ...201525342145
a real-time reverse transcription loop-mediated isothermal amplification assay for the rapid detection of yellow fever virus.yellow fever, a mosquito-borne disease, is an important viral hemorrhagic fever in africa and south america where it is endemic. detection of yellow fever virus (yfv) in africa remains a challenge due to a lack of highly specific tests. the aim of this study was to develop and optimize a rapid detection reverse transcription loop-mediated isothermal amplification (rt-lamp) for yfv. the rt-lamp was done isothermally at 62 °c using a real-time turbidimeter that allowed detection within 1h. specifi ...201323692685
taking forward a 'one health' approach for turning the tide against the middle east respiratory syndrome coronavirus and other zoonotic pathogens with epidemic potential.the appearance of novel pathogens of humans with epidemic potential and high mortality rates have threatened global health security for centuries. over the past few decades new zoonotic infectious diseases of humans caused by pathogens arising from animal reservoirs have included west nile virus, yellow fever virus, ebola virus, nipah virus, lassa fever virus, hanta virus, dengue fever virus, rift valley fever virus, crimean-congo haemorrhagic fever virus, severe acute respiratory syndrome coron ...201627321961
detection panel for identification of twelve hemorrhagic viruses using real-time rt-pcr.viral hemorrhagic fevers are caused by viruses from four viral families and develop diseases with high fatality rates. however, no commercial diagnostic assay for these pathogens is available.201425412490
development and validation of serological assays for viral hemorrhagic fevers and determination of the prevalence of rift valley fever in borno state, nigeria.rift valley fever (rvf) is endemic to the tropical regions of eastern and southern africa. the seroprevalence of rvf was investigated among the human population in borno state, nigeria to determine the occurrence of the disease in the study area in comparison with that of lassa fever and crimean-congo hemorrhagic fever.201425344695
development and evaluation of loop-mediated isothermal amplification assay for detection of crimean congo hemorrhagic fever virus in sudan.crimean-congo hemorrhagic fever (cchf) virus (cchfv) activity has been detected in kordufan region of the sudan in 2008 with high case-fatality rates in villages and rural hospitals in the region. therefore, in the present study, a reverse transcription (rt) loop-mediated isothermal amplification (rt-lamp) assay was developed and compared to nested rt-pcr for rapid detection of cchfv targeting the small (s) rna segment. a set of rt-lamp primers, designed from a highly conserved region of the s s ...201323542058
identification of novel 5,6-dimethoxyindan-1-one derivatives as antiviral agents.discovery of novel antiviral agents is essential because viral infection continues to threaten human life globally. various heterocyclic small molecules have been developed as antiviral agents. the 5,6-dimethoxy indan-1-one nucleus is of considerable interest as this ring is the key constituent in a range of bioactive compounds, both naturally occurring and synthetic, and often of considerable complexity.201728359234
immuno-chromatographic wicking assay for the rapid detection of dengue viral antigens in mosquitoes (diptera: culicidae).there is a threat for dengue virus (denv) reemergence in many regions of the world, particularly in areas where the denv vectors, aedes aegypti (l.) and aedes albopictus (skuse), are readily available. however, there are currently no accurate and reliable diagnostic methods to provide critical, real-time information for early detection of denv within the vector populations to implement appropriate vector control and personal protective measures. in this article, we report the ability of an immun ...201424605472
sar analysis of a series of acylthiourea derivatives possessing broad-spectrum antiviral activity.a series of acylthiourea derivatives were designed, synthesized, and evaluated for broad-spectrum antiviral activity with selected viruses from poxviridae (vaccinia virus) and two different genera of the family bunyaviridae (rift valley fever and la crosse viruses). a compound selected from a library screen, compound 1, displayed submicromolar antiviral activity against both vaccinia virus (ec(50)=0.25 μm) and la crosse virus (ec(50)=0.27 μm) in cytopathic effect (cpe) assays. sar analysis was p ...201222664128
discovery of novel small molecule inhibitors of lim domain kinase for inhibiting hiv-1.a dynamic actin cytoskeleton is necessary for viral entry, intracellular migration, and virion release. for hiv-1 infection, during entry, the virus triggers early actin activity through hijacking chemokine coreceptor signaling which activates a host dependency factor cofilin and its kinase, the lim domain kinase (limk). although knockdown of human limk1 with shrna inhibits hiv infection, no specific small molecule inhibitor of limk was available. here we describe the design and discovery of nov ...201728381571
notes from the field: rift valley fever response - kabale district, uganda, march 2016.on march 9, 2016, a male butcher from kabale district, uganda, aged 45 years, reported to the kabale regional referral hospital with fever, fatigue, and headache associated with black tarry stools and bleeding from the nose. one day later, a student aged 16 years from a different sub-county in kabale district developed similar symptoms and was admitted to the same hospital. the student also had a history of contact with livestock. blood specimens collected from both patients were sent for testin ...201627811840
bcx4430 - a broad-spectrum antiviral adenosine nucleoside analog under development for the treatment of ebola virus disease.the adenosine nucleoside analog bcx4430 is a direct-acting antiviral drug under investigation for the treatment of serious and life-threatening infections from highly pathogenic viruses, such as the ebola virus. cellular kinases phosphorylate bcx4430 to a triphosphate that mimics atp; viral rna polymerases incorporate the drug's monophosphate nucleotide into the growing rna chain, causing premature chain termination. bcx4430 is active in vitro against many rna viral pathogens, including the filo ...201727095300
the risk of nosocomial transmission of rift valley 2000, we investigated the rift valley fever (rvf) outbreak on the arabian peninsula-the first outside africa-and the risk of nosocomial transmission. in a cross-sectional design, during the peak of the epidemic at its epicenter, we found four (0.6%) of 703 healthcare workers (hcws) igm seropositive but all with only community-associated exposures. standard precautions are sufficient for hcws exposed to known rvf patients, in contrast to other viral hemorrhagic fevers (vhf) such as ebola virus ...201526694834
evaluation of transmission risks associated with in vivo replication of several high containment pathogens in a biosafety level 4 laboratory.containment level 4 (cl4) laboratories studying biosafety level 4 viruses are under strict regulations to conduct nonhuman primate (nhp) studies in compliance of both animal welfare and biosafety requirements. nhps housed in open-barred cages raise concerns about cross-contamination between animals, and accidental exposure of personnel to infectious materials. to address these concerns, two nhp experiments were performed. one examined the simultaneous infection of 6 groups of nhps with 6 differe ...201425059478
meta-analysis of high-throughput datasets reveals cellular responses following hemorrhagic fever virus infection.the continuing use of high-throughput assays to investigate cellular responses to infection is providing a large repository of information. due to the large number of differentially expressed transcripts, often running into the thousands, the majority of these data have not been thoroughly investigated. advances in techniques for the downstream analysis of high-throughput datasets are providing additional methods for the generation of additional hypotheses for further investigation. the large nu ...201121994748
exotic emerging viral diseases: progress and challenges.the agents causing viral hemorrhagic fever (vhf) are a taxonomically diverse group of viruses that may share commonalities in the process whereby they produce systemic and frequently fatal disease. significant progress has been made in understanding the biology of the ebola virus, one of the best known examples. this knowledge has guided our thinking about other vhf agents, including marburg, lassa, the south american arenaviruses, yellow fever, crimean-congo and rift valley fever viruses. compa ...200415577929
an assessment of zoonotic and production limiting pathogens in rusa deer (cervus timorensis rusa) from mauritius.a population of approximately 70,000 rusa deer (cervus timorensis russa) represents the most important mammal species reared for food on the island of mauritius, being the main source of red meat for the local population. however, very limited information is available on the circulation of pathogens affecting the productivity and health of this species. to produce baseline data on the circulation of infectious pathogens in rusa deer under production, a serological survey and/or direct pathogen d ...201424382104
ocular pathology: role of emerging viruses in the asia-pacific region-a review.the role of viral infections in ocular pathology varies greatly, involving all the components of the eye. some viruses like herpes simplex, herpes zoster, adenovirus, enterovirus 70, influenza virus, human immunodeficiency virus, and cytomegalovirus are well-known for their role in ocular pathology. in recent years, emerging and resurging viral infections represent an important public health problem. the asia-pacific region has witnessed a number of pandemic and epidemic outbreaks caused by thes ...201726107917
[preparation and characterization of a monoclonal antibody against the nucleocapsid protein of schmallenberg virus].the present study was conducted to prepare and characterize a monoclonal antibody (mab) against the nucleocapsid (n) protein of schmallenberg virus (sbv).201424606749
vaccines against diseases transmitted from animals to humans: a one health paradigm.this review focuses on the immunization of animals as a means of preventing human diseases (zoonoses). three frameworks for the use of vaccines in this context are described, and examples are provided of successes and failures. framework i vaccines are used for protection of humans and economically valuable animals, where neither plays a role in the transmission cycle. the benefit of collaborations between animal health and human health industries and regulators in developing such products is di ...201324060567
expression and purification of the nucleocapsid protein of schmallenberg virus, and preparation and characterization of a monoclonal antibody against this protein.schmallenberg virus (sbv) is a novel orthobunyavirus that primarily infects ruminants such as cattle, sheep and goats. the nucleocapsid (n) protein of sbv has been shown to be an ideal target antigen for serological detection. to prepare a monoclonal antibody (mab) against the n protein, the full-length coding sequence of the sbv n gene was cloned into pet-28a-c(+) and pmal-c5x vectors to generate two recombinant plasmids, which were expressed in escherichia coli bl21 as histidine (his)-tagged ( ...201323988909
eradication of transboundary animal diseases: can the rinderpest success story be repeated?a matrix system was developed to aid in the evaluation of the technical amenability to eradication, through mass vaccination, of transboundary animal diseases (tads). the system involved evaluation of three basic criteria - disease management efficiency, surveillance and epidemiological factors - each in turn comprised of a number of elements (17 in all). on that basis, 25 tads that have occurred or do occur in southern africa and for which vaccines are available, in addition to rinderpest (inco ...201726104982
protection against rift valley fever virus infection in mice upon administration of interferon-inducing rna transcripts from the fmdv this work we have addressed the effect of synthetic, non-infectious, rna transcripts, mimicking structural domains of the non-coding regions (ncrs) of the foot-and-mouth disease virus (fmdv) genome on the infection of mice with rift valley fever virus (rvfv). groups of 5 mice were inoculated intraperitoneally (i.p.) with 200 μg of synthetic rna resembling the 5'-terminal s region, the internal ribosome entry site (ires) or the 3'-ncr of the fmdv genome. rna inoculation was performed 24h befor ...201424973761
enriching pathogen transcripts from infected samples: a capture-based approach to enhanced host-pathogen rna fully understand the interactions of a pathogen with its host, it is necessary to analyze the rna transcripts of both the host and pathogen throughout the course of an infection. although this can be accomplished relatively easily on the host side, the analysis of pathogen transcripts is complicated by the overwhelming amount of host rna isolated from an infected sample. even with the read depth provided by second-generation sequencing, it is extremely difficult to get enough pathogen reads f ...201323535274
evaluation of nonspreading rift valley fever virus as a vaccine vector using influenza virus hemagglutinin as a model antigen.virus replicon particles are capable of infection, genome replication and gene expression, but are unable to produce progeny virions, rendering their use inherently safe. by virtue of this unique combination of features, replicon particles hold great promise for vaccine applications. we previously developed replicon particles of rift valley fever virus (rvfv) and demonstrated their high efficacy as a rvfv vaccine in the natural target species. we have now investigated the feasibility of using th ...201425066737
ocular manifestations of emerging infectious diseases.emergent and resurgent infectious diseases are major causes of systemic morbidity and death that are expanding worldwide mainly because of climate changes and globalization. among them, specific diseases have been recently associated with ocular involvement. this review presents the ocular manifestations of selected emerging infectious diseases relevant to the ophthalmologist.201324030241
new infectious etiologies for posterior uveitis.emergent and resurgent arthropod vector-borne diseases are major causes of systemic morbidity and death and expanding worldwide. among them, viral and bacterial agents including west nile virus, dengue fever, chikungunya, rift valley fever, and rickettsioses have been recently associated with an array of ocular manifestations. these include anterior uveitis, retinitis, chorioretinitis, retinal vasculitis and optic nerve involvement. proper clinical diagnosis of any of these infectious diseases i ...201323258387
immunogenicity and efficacy of a chimpanzee adenovirus-vectored rift valley fever vaccine in mice.rift valley fever (rvf) is a viral zoonosis that historically affects livestock production and human health in sub-saharan africa, though epizootics have also occurred in the arabian peninsula. whilst an effective live-attenuated vaccine is available for livestock, there is currently no licensed human rvf vaccine. replication-deficient chimpanzee adenovirus (chad) vectors are an ideal platform for development of a human rvf vaccine, given the low prevalence of neutralizing antibodies against the ...201324304565
extended protection against phlebovirus infection conferred by recombinant adenovirus expressing consensus interferon (def201).punta toro virus (ptv; bunyaviridae, phlebovirus) is related to rift valley fever virus (rvfv), a pathogenic agent which causes severe disease in humans and livestock primarily in the sub-saharan region of africa. the recent range expansion of rvfv and the potential for its intentional release into naïve populations pose a significant threat to public health and agriculture. studies modeling disease in rodents and nonhuman primates have shown that ptv and rvfv are highly sensitive to the antivir ...201222615273
presence of viral rna and proteins in exosomes from cellular clones resistant to rift valley fever virus infection.rift valley fever virus (rvfv) is a rna virus that belongs to the genus phlebovirus, family bunyaviridae. it infects humans and livestock and causes rift valley fever. rvfv is considered an agricultural pathogen by the usda, as it can cause up to 100% abortion in cattle and extensive death of newborns. in addition, it is designated as category a pathogen by the cdc and the niaid. in some human cases of rvfv infection, the virus causes fever, ocular damage, liver damage, hemorrhagic fever, and de ...201626904012
the use of nanotrap particles as a sample enrichment method to enhance the detection of rift valley fever virus.rift valley fever virus (rvfv) is a zoonotic virus that is not only an emerging pathogen but is also considered a biodefense pathogen due to the threat it may cause to public health and national security. the current state of diagnosis has led to misdiagnosis early on in infection. here we describe the use of a novel sample preparation technology, nanotrap particles, to enhance the detection of rvfv. previous studies demonstrated that nanotrap particles lead to both 100 percent capture of protei ...201323861988
nuclear trafficking of proteins from rna viruses: potential target for antivirals?a key aspect of the infectious cycle of many viruses is the transport of specific viral proteins into the host cell nucleus to perturb the antiviral response. examples include a number of rna viruses that are significant human pathogens, such as human immunodeficiency virus (hiv)-1, influenza a, dengue, respiratory syncytial virus and rabies, as well agents that predominantly infect livestock, such as rift valley fever virus and venezuelan equine encephalitis virus. inhibiting the nuclear traffi ...201222750233
the bunyaviridae. 201425015499
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