Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| hemorrhagic fever virus-induced changes in hemostasis and vascular biology. | viral hemorrhagic fever (vhf) denotes a virus-induced acute febrile, hemorrhagic disease reported from wide areas of the world. hemorrhagic fever (hf) viruses are encapsulated, single-stranded rna viruses that are associated with insect or rodent vectors whose interaction with humans defines the mode of disease transmission. there are 14 hf viruses, which belong to four viral families: arenaviridae, bunyaviridae, filoviridae and flaviviridae. this review presents, in order, the following aspects ... | 2000 | 10937808 |
| the growing threat of arbovirus transmission and outbreaks in kenya: a review. | to review the trend in arbovirus outbreaks and activity in kenya in the last ten years. | 2001 | 12199448 |
| viral hemorrhagic fever hazards for travelers in africa. | this short review covers 6 viral hemorrhagic fevers (vhfs) that are known to occur in africa: yellow fever, rift valley fever, crimean-congo hemorrhagic fever, lassa fever, marburg virus disease, and ebola hemorrhagic fever. all of these have at one time or another affected travelers, often the adventurous kind who are "roughing it" in rural areas, who should therefore be made aware by their physicians or travel health clinics about their potential risk of exposure to any vhf along their travel ... | 2001 | 11595975 |
| seroprevalence of rift valley fever among slaughterhouse personnel in makkah during hajj 1419h (1999). | determine the sero-prevalence of rift valley fever (rvf) among slaughterhouse personnel in makkah during hajj and define personal and work place correlates. | 2001 | 23008651 |
| the potential role of rattus rattus in enzootic cycle of rift valley fever in egypt. 1-detection of rvf antibodies in r. rattus blood samples by both enzyme linked immuno sorbent assay (elisa) and immuno-diffusion technique (id). | three hundreds of rattus rattus (r. rattus) were trapped from 3 different governorates of egypt (one hundred each), blood samples were withdrawal and subjected for detection of anti-rvf antibodies by both elisa and id techniques. the prevalence rate of antibodies by elisa were 88 (29.33%) positive out of 300 tested blood samples, the highest rate was in behira governorate 36 (36%) and the lowest one was in alexandria governorate 22 (22%) while it was 30 (30%) in minia governorate. but when id te ... | 2001 | 17216936 |
| application of reverse transcriptase-polymerase chain reaction for detection of rift valley fever viral antigen from mosquito. | a reverse transcriptase polymerase chain reaction (rt-pcr) was applied to detect rift valley fever virus (rvfv) in culex pipiens mosquito pools collected from alexandria and behira governorates of egypt (50 pools each). all mosquito pools were subjected to double sandwich enzyme linked immunosorbent assay (elisa) technique to detect rvf viral antigen. out of all 100 mosquito pools, only 18(18%) were positive by elisa, 10(20%) out of 50 pools were positive in behira governorate and 8(16%) were po ... | 2001 | 17216948 |
| quantitative real-time pcr detection of rift valley fever virus and its application to evaluation of antiviral compounds. | the rift valley fever virus (rvfv), a member of the genus phlebovirus (family bunyaviridae) is an enveloped negative-strand rna virus with a tripartite genome. until 2000, rvfv circulation was limited to the african continent, but the recent deadly outbreak in the arabian peninsula dramatically illustrated the need for rapid diagnostic methods, effective treatments, and prophylaxis. a method for quantifying the small rna segment by a real-time detection reverse transcription (rt)-pcr using taqma ... | 2001 | 11724861 |
| climate-disease connections: rift valley fever in kenya. | all known rift valley fever(rvf) outbreaks in kenya from 1950 to 1998 followed periods of abnormally high rainfall. on an interannual scale, periods of above normal rainfall in east africa are associated with the warm phase of the el niño/southern oscillation (enso) phenomenon. anomalous rainfall floods mosquito-breeding habitats called dambos, which contain transovarially infected mosquito eggs. the eggs hatch aedes mosquitoes that transmit the rvf virus preferentially to livestock and to human ... | 2001 | 11426274 |
| a reassortant bunyavirus isolated from acute hemorrhagic fever cases in kenya and somalia. | in late 1997 and early 1998, a large outbreak of hemorrhagic fever occurred in east africa. clinical samples were collected in kenya and southern somalia, and 27 of 115 (23%) hemorrhagic fever patients tested showed evidence of acute infection with rift valley fever (rvf) virus as determined by igm detection, virus isolation, detection of virus rna by reverse transcription-polymerase chain reaction (rt-pcr), or immunohistochemistry. however, two patients (one from kenya and the other from somali ... | 2001 | 11878887 |
| activity of toscana and rift valley fever virus transcription complexes on heterologous templates. | a transcription system for toscana virus (tosv) (a member of the family bunyaviridae:, genus phlebovirus:) was constructed. for in vivo expression, the tosv transcription system uses the viral n and l proteins and an s-like rna genome containing the chloramphenicol acetyltransferase reporter gene in the antisense orientation flanked by the viral genomic 5'- and 3'-terminal s sequences. it was found that the n and l proteins represent the minimal protein requirement for an active transcription co ... | 2001 | 11257182 |
| rift valley fever outbreak, mauritania, 1998: seroepidemiologic, virologic, entomologic, and zoologic investigations. | a rift valley fever outbreak occurred in mauritania in 1998. seroepidemiologic and virologic investigation showed active circulation of the rift valley fever virus, with 13 strains isolated, and 16% (range 1.5%-38%) immunoglobulin (ig) m-positivity in sera from 90 humans and 343 animals (sheep, goats, camels, cattle, and donkeys). one human case was fatal. | 2001 | 11747742 |
| arbovirus surveillance from 1990 to 1995 in the barkedji area (ferlo) of senegal, a possible natural focus of rift valley fever virus. | surveillance for mosquito-borne viruses was conducted in barkedji area from 1990 to 1995, following an outbreak of rift valley fever (rvf) virus in southern mauritania. mosquitoes, sand flies, and midges were collected from human bait and trapped by solid-state u.s. army battery-powered cdc miniature light traps baited with dry ice or animals (sheep or chickens) at four ponds. overall, 237,091 male and female mosquitoes representing 52 species in eight genera, 214,967 phlebotomine sand flies, an ... | 2001 | 11476327 |
| interferon-induced rat mx proteins confer resistance to rift valley fever virus and other arthropod-borne viruses. | mx proteins belong to the interferon (ifn)-induced antiviral defense. the rat genome contains three mx genes, ratmx1, ratmx2, and ratmx3. the mx gene products differ in their subcellular localization and antiviral specificity. the nuclear ratmx1 protein confers resistance to influenza a virus, and the cytoplasmic ratmx2 is active against vesicular stomatitis virus (vsv), whereas the cytoplasmic ratmx3 protein is antivirally inactive. to investigate the antiviral potential of the rat mx proteins ... | 2001 | 11576460 |
| genetic evidence for an interferon-antagonistic function of rift valley fever virus nonstructural protein nss. | rift valley fever virus (rvfv), a phlebovirus of the family bunyaviridae, is a major public health threat in egypt and sub-saharan africa. the viral and host cellular factors that contribute to rvfv virulence and pathogenicity are still poorly understood. all pathogenic rvfv strains direct the synthesis of a nonstructural phosphoprotein (nss) that is encoded by the smallest (s) segment of the tripartite genome and has an undefined accessory function. in this report, we show that mp12 and clone 1 ... | 2001 | 11152510 |
| single-tube and nested reverse transcriptase-polymerase chain reaction for detection of rift valley fever virus in human and animal sera. | rift valley fever (rvf) is an anthropozoonosis caused by a phlebovirus (bunyaviridae family) that has re-emerged recently in east and west africa in 1997-1998. this emphasizes the need for early and rapid detection of the virus and an efficient surveillance system. to this goal, a single tube or a nested reverse transcriptase-polymerase chain reaction (rt-pcr) method focusing on the nss coding region of the s segment was developed and used to detect the rvf virus (rvfv) genome, resulting respect ... | 2001 | 11164489 |
| development of a diagnostic one-tube rt-pcr for the detection of rift valley fever virus. | diagnosis of rift valley fever (rvf) is based on serology and virus isolation. the disadvantages of the former include poor sensitivity, high cost, risks associated with using infectious virus as antigen, the lengthy duration of elisa as well as cross-reactivity with other phleboviruses. we developed, optimised and evaluated a one-tube reverse-transcription-polymerase chain reaction (rt-pcr) for the detection of rift valley fever virus (rvfv) in ruminants. the pcr primers for this assay were des ... | 2002 | 12356173 |
| an outbreak of rift valley fever in northeastern kenya, 1997-98. | in december 1997, 170 hemorrhagic fever-associated deaths were reported in garissa district, kenya. laboratory testing identified evidence of acute rift valley fever virus (rvfv). of the 171 persons enrolled in a cross-sectional study, 31(18%) were anti-rvfv immunoglobulin (ig) m positive. an age-adjusted igm antibody prevalence of 14% was estimated for the district. we estimate approximately 27,500 infections occurred in garissa district, making this the largest recorded outbreak of rvfv in eas ... | 2002 | 11897064 |
| isolation of west nile and sindbis viruses from mosquitoes collected in the nile valley of egypt during an outbreak of rift valley fever. | as part of an evaluation of potential vectors of arboviruses during a rift valley fever (rvf) outbreak in the nile valley of egypt in august 1993, we collected mosquitoes in villages with known rvf viral activity. mosquitoes were sorted to species, pooled, and processed for virus isolation both by intracerebral inoculation into suckling mice and by inoculation into cell culture. a total of 33 virus isolates was made from 36,024 mosquitoes. viruses were initially identified by indirect fluorescen ... | 2002 | 11931267 |
| diagnostic pathology of selected diseases in wildlife. | the prompt detection and effective management of infectious disease in wildlife rely greatly on field diagnosis. although clinical work is sometimes of value, the cornerstone of diagnosis is pathological examination (gross necropsy with supporting laboratory investigations). the approach and rationale to gross post-mortem examination are common to all species, despite possible significant differences in technique. likewise, the principles of sampling are usually comparable, with emphasis on stan ... | 2002 | 11974632 |
| use of reverse transcriptase pcr in early diagnosis of rift valley fever. | reverse transcriptase pcr (rt-pcr) for diagnosis of rift valley fever (rvf) was evaluated by using 293 human and animal sera sampled during an rvf outbreak in mauritania in 1998. results of the rt-pcr diagnostic method were compared with those of virus isolation (vi) and detection of immunoglobulin m (igm) antibodies. our results showed that rt-pcr is a specific, sensitive tool for rvf diagnosis in the early phase of the disease and that its results do not differ significantly from those obtaine ... | 2002 | 11986283 |
| rapid detection and quantification of rna of ebola and marburg viruses, lassa virus, crimean-congo hemorrhagic fever virus, rift valley fever virus, dengue virus, and yellow fever virus by real-time reverse transcription-pcr. | viral hemorrhagic fevers (vhfs) are acute infections with high case fatality rates. important vhf agents are ebola and marburg viruses (mbgv/ebov), lassa virus (lasv), crimean-congo hemorrhagic fever virus (cchfv), rift valley fever virus (rvfv), dengue virus (denv), and yellow fever virus (yfv). vhfs are clinically difficult to diagnose and to distinguish; a rapid and reliable laboratory diagnosis is required in suspected cases. we have established six one-step, real-time reverse transcription- ... | 2002 | 12089242 |
| teratogenicity of a mutagenised rift valley fever virus (mvp 12) in sheep. | a 5-fluorouracil mutagenised rift valley fever virus strain, which was shown to be attenuated and immunogenic in cattle and sheep, was evaluated for its ability to cause teratogenic effects in pregnant sheep. a group of 50 sheep at various stages of pregnancy was inoculated with the virus and the pregnancies followed to term. there were two abortions and 14% of the lambs produced by vaccinated ewes showed teratogenic effects, the most prevalent being spinal hypoplasia, hydranencephaly, brachygna ... | 2002 | 12092782 |
| rift valley fever. | rift valley fever virus is an arthropod-borne phlebovirus endemic in sub-saharan africa. outbreaks also have occurred in egypt, madagascar, and most recently in the arabian peninsula. large epizootics occur at irregular intervals in seasons of above-average rainfall with persistent flooding and the appearance of large numbers of floodwater-breeding aedine mosquitoes. the virus is transmitted transovarially and can remain dormant in mosquito eggs during dry interepizootic periods. low-level virus ... | 2002 | 12442582 |
| genetic analysis of viruses associated with emergence of rift valley fever in saudi arabia and yemen, 2000-01. | the first confirmed rift valley fever outbreak outside africa was reported in september 2000, in the arabian peninsula. as of february 2001, a total of 884 hospitalized patients were identified in saudi arabia, with 124 deaths. in yemen, 1,087 cases were estimated to have occurred, with 121 deaths. laboratory diagnosis of rift valley fever virus (rvfv) infections included virus genetic detection and characterization of clinical specimens by reverse transcription-polymerase chain reaction, in add ... | 2002 | 12498657 |
| isolation and genetic characterization of rift valley fever virus from aedes vexans arabiensis, kingdom of saudi arabia. | an outbreak of rift valley fever in the kingdom of saudi arabia and yemen in 2000 was the first recognized occurrence of the illness outside of africa and madagascar. an assessment of potential mosquito vectors in the region yielded an isolate from aedes vexans arabiensis, most closely related to strains from madagascar (1991) and kenya (1997). | 2002 | 12498669 |
| antivirally active mxa protein sequesters la crosse virus nucleocapsid protein into perinuclear complexes. | bunyaviruses replicate in the cytoplasm of infected cells. new viral particles are formed by budding of nucleocapsids into the golgi apparatus. we have previously shown that the ifn-induced human mxa protein inhibits bunyavirus replication by an unknown mechanism. here we demonstrate that mxa binds to the nucleocapsid protein of la crosse virus (lacv) and colocalizes with the viral protein in cytoplasmic complexes. electron microscopy revealed that these complexes accumulated in the perinuclear ... | 2002 | 11880649 |
| the 2000 epidemic of rift valley fever in saudi arabia: mosquito vector studies. | in mid-september 2000, rift valley fever (rvf) virus was diagnosed as the cause of infection in humans and livestock in jizan region, saudi arabia. this is the first time that this arbovirus has been found outside africa and madagascar. collections of mosquitoes (diptera: culicidae) were therefore undertaken (from 25 september to 10 october) at eight sites during the epidemic to obtain mosquitoes for attempted rvf virus isolation. among 23 699 mosquito females tested, six isolations of rvf virus ... | 2002 | 12243225 |
| bidirectional infection and release of rift valley fever virus in polarized epithelial cells. | rift valley fever (rvf) virus is an arbovirus and is responsible for large outbreaks of disease predominantly in sub-saharan africa. however, several aspects of rvf virus transmission, such as high viremia, multiple vector species, and broad host range, result in a pathogen with high likelihood of geographic spread. rvf virus infection in humans and livestock is characterized by broad dissemination of rvf virus antigens throughout the body. we sought insight into the high pathogenicity and broad ... | 2002 | 12359425 |
| characterization of the golgi retention motif of rift valley fever virus g(n) glycoprotein. | as rift valley fever (rvf) virus, and probably all members of the family bunyaviridae, matures in the golgi apparatus, the targeting of the virus glycoproteins to the golgi apparatus plays a pivotal role in the virus replication cycle. no consensus golgi localization motif appears to be shared among the glycoproteins of these viruses. the viruses of the family bunyaviridae synthesize their glycoproteins, g(n) and g(c), as a polyprotein. the golgi localization signal of rvf virus has been shown t ... | 2002 | 12414959 |
| the potential role of rattus rattus in enzootic cycle of rift valley fever in egypt 2-application of reverse transcriptase polymerase chain reaction (rt-pcr) in blood samples of rattus rattus. | a reverse transcriptase -polymerase chain reaction (rt-pcr) was applied to detect rift valley fever virus (rvf-v) in blood samples of rattus rattus (r. rattus) collected from 3 different governorates of egypt, alexandria, behira and minia governorates (one hundred each). out of 300 blood samples 29(9.67%) were positive for rvf-virus by rt-pcr with higher percent in behira governorate rural areas (16%), followed by minia governorate rural areas (13.85%) while the lowest percent was in alexandria ... | 2002 | 17219894 |
| [rift valley fever: sporadic infection of french military personnel outside currently recognized epidemic zones]. | for three years the arbovirus surveillance unit of the tropical medicine institute of the french army medical corps (french acronym imtssa) in marseille, france has been investigating causes of benign non-malarial febrile syndromes in french military personnel serving outside mainland france. the methodology used in n'djamena consisted of sending frozen specimens collected concomitant with viremia, to marseille for culture. during the rainy season of 2001, specimens were collected from a total o ... | 2002 | 12244928 |
| indirect enzyme-linked immunosorbent assay for the detection of antibody against rift valley fever virus in domestic and wild ruminant sera. | an indirect enzyme-linked immunosorbent assay (i-elisa) for the detection of specific igg immunoglobulins against rift valley fever virus (rvfv) was validated in-house. a total of 3055 sera from sheep (n = 1159), goats (n = 636), cattle (n = 203), african buffalo (n = 928), and other wild ruminants (n = 129), including eland, kudu, and black wildebeest, was used. sera from domestic ruminants were collected in west (n = 10), south (n = 1654) and east africa (n = 334), and sera from wild ruminants ... | 2003 | 12825681 |
| rift valley fever epidemic in saudi arabia: epidemiological, clinical, and laboratory characteristics. | this cohort descriptive study summarizes the epidemiological, clinical, and laboratory characteristics of the rift valley fever (rvf) epidemic that occurred in saudi arabia from 26 august 2000 through 22 september 2001. a total of 886 cases were reported. of 834 reported cases for which laboratory results were available, 81.9% were laboratory confirmed, of which 51.1% were positive for only rvf immunoglobulin m, 35.7% were positive for only rvf antigen, and 13.2% were positive for both. the mean ... | 2003 | 14523773 |
| igg-sandwich and igm-capture enzyme-linked immunosorbent assay for the detection of antibody to rift valley fever virus in domestic ruminants. | the recent occurrence of the first confirmed outbreaks of rift valley fever in humans and livestock outside the african region, namely in the kingdom of saudi arabia and yemen, is of global medical and veterinary concern. disadvantages of classical techniques for serological diagnosis of rift valley fever include health risk to laboratory personnel, restrictions for their use outside endemic areas and inability to distinguish between different classes of immunoglobulins. we report on the develop ... | 2003 | 14553896 |
| induction of severe disease in hamsters by two sandfly fever group viruses, punta toro and gabek forest (phlebovirus, bunyaviridae), similar to that caused by rift valley fever virus. | adult golden hamsters inoculated subcutaneously with either of two sandfly fever group viruses, punta toro and gabek forest (phlebovirus, bunyaviridae), developed a fulminating fatal illness characterized by hepatic and splenic necrosis and interstitial pneumonitis. most animals died within three days after infection; this was accompanied by high levels of viremia. necropsy and histopathologic examination of the infected animals revealed pathologic changes involving multiple organs that resemble ... | 2003 | 14628943 |
| tropical dermatology: viral tropical diseases. | viruses are important pathogens in tropical areas; most of them, especially the tropical hemorrhagic fevers, produce mucocutaneous manifestations. more than any other kind of pathogen, viruses have the possibility for being widespread, since they have a greater probability of mutation than do bacteria, can cross species barriers easily, and infect both human beings and animals in habitats with a great biodiversity. tropical habitats also have been subject to major ecologic changes in the last fe ... | 2003 | 14639375 |
| a retrospective study of rift valley fever in saudi arabia. | a retrospective study was undertaken to examine domestic ruminant sera for rift valley fever (rvf) virus antibodies. the sera were collected between 1992 and 1995 from cattle, sheep and goats from various locations in saudi arabia. the standard capture enzyme-linked immunosorbent assay system was employed to detect specific rvf antibodies in the animals and the results indicated an absence of rvf antibodies. this finding confirms the assumption that saudi arabia was free from rvf up until at lea ... | 2003 | 15005544 |
| viruses of the bunya- and togaviridae families: potential as bioterrorism agents and means of control. | when considering viruses of potential importance as tools for bioterrorism, several viruses in the bunya- and togaviridae families have been cited. among those in the bunyaviridae family are rift valley fever, crimean-congo hemorrhagic fever, hanta, and sandfly fever viruses, listed in order of priority. those particularly considered in the togaviridae family are venezuelan, eastern and western equine encephalitis viruses. factors affecting the selection of these viruses are the ability for them ... | 2003 | 12615306 |
| rift valley fever virus infection among french troops in chad. | 2003 | 12781023 | |
| pathogenicity and neurovirulence of a mutagen-attenuated rift valley fever vaccine in rhesus monkeys. | rhesus macaques, intravenously inoculated with virulent rift valley fever virus, develop viremia and biochemical evidence of liver damage and serve as a model for human disease. some of these monkeys suffer more serious disease with hemorrhagic phenomena and approximately 20% die with frank hemorrhage. presently, the only rift valley fever vaccine approved for use in humans is a formalin-killed product that requires annual booster vaccinations. efforts to produce an improved vaccine to replace t ... | 2003 | 12798643 |
| detection and identification of toscana and other phleboviruses by rt-nested-pcr assays with degenerated primers. | phleboviruses are a large and widespread group of viruses that are transmitted by arthropods. toscana virus is one of the principal agents that causes meningitis in humans during the summer in italy and, possibly, in other mediterranean countries. rift valley fever virus can cause serious illness in both animals and humans, leading to high morbidity and mortality, and is considered to be a potential agent for epizootics and human epidemics. since information on this group of viruses is still sca ... | 2003 | 12858420 |
| phylogenetic analysis reveals a low rate of homologous recombination in negative-sense rna viruses. | recombination is increasingly seen as an important means of shaping genetic diversity in rna viruses. however, observed recombination frequencies vary widely among those viruses studied to date, with only sporadic occurrences reported in rna viruses with negative-sense genomes. to determine the extent of homologous recombination in negative-sense rna viruses, phylogenetic analyses of 79 gene sequence alignments from 35 negative-sense rna viruses (a total of 2154 sequences) were carried out. powe ... | 2003 | 13679603 |
| rift valley fever: an uninvited zoonosis in the arabian peninsula. | rift valley fever (rvf) is an acute viral disease, affecting mainly livestock but also humans. the virus is transmitted to humans through mosquito bites or by exposure to blood and bodily fluids. drinking raw, unpasteurized milk from infected animals can also transmit rvf. routine vaccination of livestock in africa has been prohibitively expensive, leading to endemicity of rvf in most african countries. reports in september 2000 first documented rvf occurring outside of africa in the kingdom of ... | 2003 | 12615379 |
| mapping rift valley fever vectors and prevalence using rainfall variations. | high activity of the rift valley fever (rvf) virus is related to a tremendous increase of associated mosquito vectors, which follows periods of high rainfall. indeed, rainfall creates an ecologically humid environment that insures the proliferation of breeding sites and the development of rvf vectors. data collected by fontenille et al. (1998) from 1991 to 1996 in the barkedji area in the northern senegal are employed to discuss and quantify the incidence of rainfall upon the abundances of rvf v ... | 2004 | 15018771 |
| rift valley fever epidemic in saudi arabia: disconcerting epidemiological defects and lack of differential diagnoses and concordance in studies. | 2004 | 15156493 | |
| rift valley fever in chad. | to evaluate the importance of human exposure to rift valley fever virus in chad, investigations were carried out to determine specific antibody prevalence in domestic ruminants during the 2002 rainy season. results highlighted recent, substantial, active transmission of this virus. | 2004 | 15200839 |
| nss protein of rift valley fever virus blocks interferon production by inhibiting host gene transcription. | rift valley fever virus (rvfv) is an important cause of epizootics and epidemics in africa and a potential agent of bioterrorism. a better understanding of the factors that govern rvfv virulence and pathogenicity is required, given the urgent need for antiviral therapies and safe vaccines. we have previously shown that rvfv strains with mutations in the nss gene are excellent inducers of alpha/beta interferon (ifn-alpha/beta) and are highly attenuated in mice. here, we demonstrate that nss is su ... | 2004 | 15331713 |
| exposure of sheep to mosquito bites: possible consequences for the transmission risk of rift valley fever in senegal. | rift valley fever (rvf) is a growing health problem in west africa. in northern senegal, the candidate vectors of this arbovirosis are aedes (aedimorphus) vexans meigen and culex (culex) poicilipes theobald (diptera: culicidae). domestic ruminants are the reservoirs of the virus. a study was undertaken during the 2002 rainy season to assess spatial and temporal variations in exposure to mosquito bites in sheep herds, and to evaluate the possible consequences on the risk of rvf transmission to sh ... | 2004 | 15347392 |
| bichat guidelines for the clinical management of haemorrhagic fever viruses and bioterrorism-related haemorrhagic fever viruses. | haemorrhagic fever viruses (hfvs) are a diverse group of viruses that cause a clinical disease associated with fever and bleeding disorder. hfvs that are associated with a potential biological threat are ebola and marburg viruses (filoviridae), lassa fever and new world arenaviruses (machupo, junin, guanarito and sabia viruses) (arenaviridae), rift valley fever (bunyaviridae) and yellow fever, omsk haemorrhagic fever, and kyanasur forest disease (flaviviridae). in terms of biological warfare con ... | 2004 | 15677844 |
| rift valley fever. | rift valley fever (rvf) is an arthropod-borne viral disease of ruminants, camels and humans. it is also a significant zoonosis which may be encountered as an uncomplicated influenza-like illness, but may also present as a haemorrhagic disease with liver involvement; there may also be ocular or neurological lesions. in animals, rvf may be inapparent in non-pregnant adults, but outbreaks are characterised by the onset of abortions and high neonatal mortality. jaundice hepatitis and death are seen ... | 2004 | 15702723 |
| the production and evaluation of a standard diagnostic peste des petits ruminants (ppr) hyperimmune serum prepared from the egyptian antigen (egypt 87). | the aim of this study was to produce a specific hyperimmune serum for diagnosis of peste des petits ruminants (ppr). based on good laboratory practices and standard operating procedures, we produced this reagent in goats using attenuated local strain of pprv. the quality was assured to meet the internationally required levels of potency and sterility. the titer of the product was 1024 as evaluated by virus neutralization (vn) and agar gel immunodiffusion (agid) tests. in its final form, it is a ... | 2004 | 15724381 |
| isolation of bovine viral diarrhea virus 1, a pestivirus from autopsied lamb specimen from tamil nadu, india. | an epizootic of febrile illness among the madras red breed of sheep had occurred in 1994 in verrapuram, chennai, india. the epizootic was suspected as rift valley fever (rvf)-like sickness based on clinical features. however, its etiological agent could neither be isolated nor implicated conclusively. during the post-epizootic period a male lamb died of similar clinical features and the spleen was immediately collected. inoculation of spleen suspension in infant mouse brain yielded a virus that ... | 2004 | 15745045 |
| [rift valley fever virus]. | rift valley fever virus (rvfv) causes massive mosquito-borne epidemics among humans and decimates ruminants in which the mortality rate is about 1% and 10-30%, respectively. morbidity in rvfv-infected humans is high largely due to the effects of hemorrhagic fever and encephalitis. this virus is native to sub-saharan africa; yet if this virus is introduced into the environment, virus transmission appears to occur whenever sheep and cattle are present with abundant mosquito populations. rvfv is a ... | 2004 | 15745161 |
| tfiih transcription factor, a target for the rift valley hemorrhagic fever virus. | the rift valley fever virus (rvfv) is the causative agent of fatal hemorrhagic fever in humans and acute hepatitis in ruminants. we found that infection by rvfv leads to a rapid and drastic suppression of host cellular rna synthesis that parallels a decrease of the tfiih transcription factor cellular concentration. using yeast two hybrid system, recombinant technology, and confocal microscopy, we further demonstrated that the nonstructural viral nss protein interacts with the p44 component of tf ... | 2004 | 14980221 |
| targeting tfiih to inhibit host cell transcription by rift valley fever virus. | in the february 20 issue of cell, report that rift valley fever virus (rvfv) targets cellular transcriptional apparatus to inhibit rna polymerase ii-mediated transcription. unlike polio and vesicular stomatitis viruses, both of which target the tata binding protein (tbp), rvfv appears to target the basal transcription factor thiih to induce shut-off of host cell transcription. | 2004 | 14992716 |
| 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 ... | 2004 | 15577929 |
| validation of igg-sandwich and igm-capture elisa for the detection of antibody to rift valley fever virus in humans. | rift valley fever (rvf) virus is an important zoonotic and a potential biothreat agent. this paper describes validation of sandwich and capture enzyme-linked immunoassays (elisa) based on gamma-irradiated antigens for the detection of rvfv-specific igg and igm antibody in humans. validation data sets derived from testing field-collected sera from africa (n=2400) were dichotomised according to the results of a virus neutralisation test. in addition, sera from laboratory workers immunized with ina ... | 2005 | 15664066 |
| rainfall patterns and population dynamics of aedes (aedimorphus) vexans arabiensis, patton 1905 (diptera: culicidae), a potential vector of rift valley fever virus in senegal. | the importance of rainfall for the development of aedes vexans arabiensis populations, one of the potential vectors of rift valley fever in west africa, was demonstrated in a two-year follow-up study conducted in the ferlo region of senegal. in 2003, the rainy season began with heavy rains and, as a result, temporary ponds, the breeding places for mosquitoes, were flooded at their maximum level immediately. in such conditions, aedes vexans arabiensis populations are abundant at the very beginnin ... | 2005 | 16007962 |
| alkhumra virus infection, a new viral hemorrhagic fever in saudi arabia. | four patients with typical acute viral hemorrhagic fever were identified in the holy city of makkah, saudi arabia, between 8 and 23 february 2001, the hajj (pilgrimage) period of that year. tests for rift valley fever (rvf), crimean-congo hemorrhagic fever (cchf), and dengue were negative. blood specimens were sent to the centres for disease control and prevention (cdc), atlanta for viral culture and testing for other hemorrhagic fever viruses. a new flavivirus closely related to the tick-borne ... | 2005 | 16038757 |
| domestic transmission of rift valley fever virus in diawara (senegal) in 1998. | in 1998, circulation of the rift valley fever (rvf) virus was revealed in diawara by detection of igm antibodies in sheep and isolation of the virus from mosquitoes caught outside a village. a seroprevalence study was carried out. finger-prick blood samples, individual and collective details were obtained. one thousand five hundred twenty people (6 months - 83 years) were included. overall prevalence in this group was approximately 5.2%. the prevalence in infants (6 months - 2 years) was 8.5%. a ... | 2005 | 16610651 |
| apoptosis of hepatocytes caused by punta toro virus (bunyaviridae: phlebovirus) and its implication for phlebovirus pathogenesis. | experimental infection of hamsters with punta toro virus (ptv) produces a disease with clinical and pathological similarities to the severe human hemorrhagic fever caused by rift valley fever virus (rvfv), thus providing an animal model for rvfv pathogenesis. in this model, hepatocytic apoptosis is the main pathological component of liver injuries that are responsible for severe hemorrhagic manifestations. to further elucidate whether viral replication in hepatocytes directly causes apoptosis, w ... | 2005 | 16192639 |
| rift valley fever in small ruminants, senegal, 2003. | during the 2003 rainy season, the clinical and serologic incidence of rift valley fever was assessed in small ruminant herds living around temporary ponds located in the semi-arid region of the ferlo, senegal. no outbreak was detected by the surveillance system. serologic incidence was estimated at 2.9% (95% confidence interval 1.0-8.7) and occurred in 5 of 7 ponds with large variations in the observed incidence rate (0%-20.3%). the location of ponds in the ferlo valley and small ponds were corr ... | 2005 | 16318720 |
| pathogenesis of rift valley fever virus in mosquitoes--tracheal conduits & the basal lamina as an extra-cellular barrier. | knowledge of the fate of an arbovirus in a mosquito is fundamental to understanding the mosquito's competence to transmit the virus. when a competent mosquito ingests viremic vertebrate blood, virus infects midgut epithelial cells and replicates, then disseminates to other tissues, including salivary glands and/or ovaries. the virus is then transmitted to the next vertebrate host horizontally via bite and/or vertically to the mosquito's offspring. not all mosquitoes that ingest virus become infe ... | 2005 | 16355869 |
| aspects of bioecology of two rift valley fever virus vectors in senegal (west africa): aedes vexans and culex poicilipes (diptera: culicidae). | the dispersal, population dynamics, and age structure of two rift valley fever virus (phlebovirus: bunyaviridae) (rvfv) vectors, aedes vexans meigen and culex poicilipes theobald, were investigated in northern senegal. the main objective was to investigate possible factors that mediate rvfv emergence and propagation at a site where humans and livestock live in proximity to temporary surface pools. in mark-release-recapture studies, recapture rates of 0.18% (156/85,500) and 3.46% (201/5,800) were ... | 2005 | 16363157 |
| rift valley fever virus. | rift valley fever is considered to be one of the most important viral zoonoses in africa. in 2000, the rift valley fever virus spread to the arabian peninsula and caused two simultaneous outbreaks in yemen and saudi arabia. it is transmitted to ruminants and to humans by mosquitoes. the viral agent is an arbovirus, which belongs to the phlebovirus genus in the bunyaviridae family. this family of viruses comprises more than 300 members grouped into five genera: orthobunyavirus, phlebovirus, hanta ... | 2005 | 16375716 |
| the n terminus of rift valley fever virus nucleoprotein is essential for dimerization. | rift valley fever virus (rvfv) is a phlebovirus in the bunyaviridae family. the nucleoprotein n is the most abundant component of the virion; numerous copies of n associate with the viral rna genome and form pseudohelicoidal ribonucleoproteins (rnps) circularized by a panhandle structure formed by the base-paired rna sequences at the 3' and 5' termini. these structures play a central role in transcription and replication. we investigated the intermolecular interactions of the rvfv n protein and ... | 2005 | 16140773 |
| rift valley fever virus nss mrna is transcribed from an incoming anti-viral-sense s rna segment. | analysis of purified rift valley fever virus (rvfv) particles demonstrated the presence of three negative-sense rna genomes, plus three anti-viral-sense rna segments. the virion-associated anti-viral-sense s segment served as a template for the synthesis of nss mrna immediately after infection. nss protein synthesis also occurred early in infection, suggesting that nss protein produced early in infection probably has biologically significant roles in virus replication and/or survival in the host ... | 2005 | 16140788 |
| immune responses to recombinants of the south african vaccine strain of lumpy skin disease virus generated by using thymidine kinase gene insertion. | the south african vaccine strain of lumpy skin disease virus (type sa-neethling) is currently being developed as a vector for recombinant vaccines of economically important livestock diseases throughout africa. in this study, the feasibility of using the viral thymidine kinase gene as the site of insertion was investigated and recombinant viruses were evaluated in animal trials. two separate recombinants were generated and selected for homogeneity expressing either the structural glycoprotein ge ... | 2005 | 15811653 |
| rift valley fever virus nonstructural protein nss promotes viral rna replication and transcription in a minigenome system. | rift valley fever virus (rvfv), which belongs to the genus phlebovirus, family bunyaviridae, has a tripartite negative-strand genome (s, m, and l segments) and is an important mosquito-borne pathogen for domestic animals and humans. we established an rvfv t7 rna polymerase-driven minigenome system in which t7 rna polymerase from an expression plasmid drove expression of rna transcripts for viral proteins and minigenome rna transcripts carrying a reporter gene between both termini of the m rna se ... | 2005 | 15827175 |
| an inhibition enzyme-linked immunosorbent assay for the detection of antibody to rift valley fever virus in humans, domestic and wild ruminants. | this paper describes the development and validation of an inhibition elisa based on gamma-irradiated tissue culture-derived antigen for the detection of antibody to rift valley fever virus (rvfv) in humans, domestic and wild ruminants. validation data sets derived from field-collected sera in africa (humans=1367, cattle=649, goats=806, sheep=493, buffalo=258, camels=156) were categorized according to the results of a virus neutralisation test. in addition, individual sera from 93 laboratory work ... | 2005 | 15893560 |
| mosquito vectors of the 1998-1999 outbreak of rift valley fever and other arboviruses (bagaza, sanar, wesselsbron and west nile) in mauritania and senegal. | following an outbreak of rift valley fever (rvf) in south-eastern mauritania during 1998, entomological investigations were conducted for 2 years in the affected parts of senegal and mauritania, spanning the sénégal river basin. a total of 92 787 mosquitoes (diptera: culicidae), belonging to 10 genera and 41 species, were captured in light traps. in senegal, culex poicilipes (41%) and mansonia uniformis (39%) were the most abundant species caught, whereas aedes vexans (77%) and cx. poicilipes (1 ... | 2005 | 15958020 |
| clinical aspects of african viral hemorrhagic fevers. | three hemorrhagic fevers occur in southern africa: rift valley fever, marburg virus disease, and crimean-congo hemorrhagic fever. the patient's history of travel in africa, visits to rural areas, contact with sick animals or their carcasses, or contact with a tick-infested environment or tick bites is important. rift valley fever is characterized by an incubation period of approximately 3 or 4 days, sudden onset of fever with a biphasic course, and signs and symptoms of liver and kidney disorder ... | 2005 | 2665013 |
| [viral encephalitis virus, a new bioterrorist menace]. | often responsible for little known infections, today viral encephalitis viruses appear as a new bioterrorist menace, because of their easy production and their great pathogenic potential. spraying is the best way to permit the rapid diffusion of certain encephalitis viruses. diagnosis of viral encephalitis, predominating in tropical surroundings, is difficult. in the majority of cases, symptoms differ little from those of common flu. with supplementary examinations, the biological abnormalities ... | 2005 | 15687967 |
| rift valley fever in west africa: the role of space in endemicity. | rift valley fever is an endemic vector-borne disease in west africa, which mainly affects domestic ruminants and occasionally humans. the aetiological mechanisms of its endemicity remain under debate. we used a simple spatially explicit model to assess the possibility of endemicity without wild animals providing a permanent virus reservoir. our model takes into account the vertical transmission in some mosquito species, the rainfall-driven emergence of their eggs and local and distant contacts b ... | 2006 | 17176353 |
| immunogenicity of combination dna vaccines for rift valley fever virus, tick-borne encephalitis virus, hantaan virus, and crimean congo hemorrhagic fever virus. | dna vaccines for rift valley fever virus (rvfv), crimean congo hemorrhagic fever virus (cchfv), tick-borne encephalitis virus (tbev), and hantaan virus (htnv), were tested in mice alone or in various combinations. the bunyavirus vaccines (rvfv, cchfv, and htnv) expressed gn and gc genes, and the flavivirus vaccine (tbev) expressed the prem and e genes. all vaccines were delivered by gene gun. the tbev dna vaccine and the rvfv dna vaccine elicited similar levels of antibodies and protected mice f ... | 2006 | 16174542 |
| tlr3 deletion limits mortality and disease severity due to phlebovirus infection. | tlr3 was the first member of the tlr family of pattern recognition receptors found to detect a conserved viral molecular pattern, dsrna, yet supporting evidence for a major role in host defense against viral pathogens is limited. punta toro virus (ptv) has been shown to produce severe infection in mice, modeling disease caused by the related highly pathogenic rift valley fever phlebovirus in humans and domesticated ungulates. using tlr3-deficient mice, we investigated the involvement of tlr3 in ... | 2006 | 17056560 |
| tlr3 deletion limits mortality and disease severity due to phlebovirus infection. | tlr3 was the first member of the tlr family of pattern recognition receptors found to detect a conserved viral molecular pattern, dsrna, yet supporting evidence for a major role in host defense against viral pathogens is limited. punta toro virus (ptv) has been shown to produce severe infection in mice, modeling disease caused by the related highly pathogenic rift valley fever phlebovirus in humans and domesticated ungulates. using tlr3-deficient mice, we investigated the involvement of tlr3 in ... | 2006 | 17056560 |
| rescue of infectious rift valley fever virus entirely from cdna, analysis of virus lacking the nss gene, and expression of a foreign gene. | rift valley fever virus (rvfv) (genus phlebovirus, family bunyaviridae) has a tripartite negative-strand genome, causes a mosquito-borne disease that is endemic in sub-saharan african countries and that also causes large epidemics among humans and livestock. furthermore, it is a bioterrorist threat and poses a risk for introduction to other areas. in spite of its danger, neither veterinary nor human vaccines are available. we established a t7 rna polymerase-driven reverse genetics system to resc ... | 2006 | 16501102 |
| [the mammals of guinea as reservoirs and carriers of arboviruses]. | a great body of data on the fauna and ecology of wild mammals and their participation in the circulation of arboviruses were collected when the ecology of the latter of the republic of guinea was studied in 1978 to 1989. a hundred and eighteen species belonging to 10 orders were identified. over 2,000 biological specimens were virologically and serologically examined. six arboviruses were isolated. these included dugbe virus (from the hussar monkey cercopithecus (erythrocebus patas) and 5 viruse ... | 2006 | 16562748 |
| [feeding pattern of rift valley fever virus vectors in senegal. implications in the disease epidemiology]. | during the rainy season 2003, an entomological survey was undertaken in the sahelian bioclimatic zone of the ferlo area in northern senegal, in order to evaluate the degree of interaction between rift valley fever (rvf) virus vectors and domestic animals and to determine the role of natural vertebrate hosts in the transmission and maintenance cycle. the study of vector-host contact was carried out under bed net traps using man, cow, sheep, chicken as bait whereas the rvfv vectors-vertebrate host ... | 2006 | 17111980 |
| regional and international approaches on prevention and control of animal transboundary and emerging diseases. | transboundary animal diseases pose a serious risk to the world animal agriculture and food security and jeopardize international trade. the world has been facing devastating economic losses from major outbreaks of transboundary animal diseases (tads) such as foot-and-mouth disease, classical swine fever, rinderpest, peste des petits ruminants (ppr), and rift valley fever. lately the highly pathogenic avian influenza (hpai) due to h5n1 virus, has become an international crisis as all regions arou ... | 2006 | 17135498 |
| descriptive and spatial epidemiology of rift valley fever outbreak in yemen 2000-2001. | rift valley fever (rvf) is an arboviral disease produced by a bunyavirus belonging to the genus phlebovirus. several species of aedes and culex are the vectors of this virus that affects sheep, goats, buffalos, cattle, camels and human beings. the human disease is well known, especially during periods of intense epizootic activity. the initial description of the disease dates back to 1930, when animals and human outbreaks appeared on a farm in lake naivasha, in the great rift valley of kenya. un ... | 2006 | 17135517 |
| adverse response of non-indigenous cattle of european breeds to live attenuated smithburn rift valley fever vaccine. | three hundred eighteen european cows and 115 buffaloes were vaccinated with locally prepared smithburn vaccine, of which, 100 cows and 20 buffaloes were pregnant. twenty-eight cows aborted within 72 days post-vaccination, buffaloes did not abort. blood samples collected 77 days post-vaccination from aborted cows, 17 pregnant cows, 5 pregnant buffaloes, and 32 non-pregnant cows. sera were tested by elisa for anti-rvf igm and igg. all aborted cows were strongly positive for igg. five of 17 cows an ... | 2006 | 16628582 |
| rift valley fever virus noncoding regions of l, m and s segments regulate rna synthesis. | rift valley fever virus (rvfv) (phlebovirus, bunyaviridae) possesses a genome composed of three negative-stranded rna molecules. each segment contains 3' and 5' noncoding regions with terminal complementary sequences forming a panhandle structure. we showed that transcription-replication of the l, m and s segments is regulated, and we established a minigenome rescue system expressing a cat reporter to investigate the role of the noncoding regions in this process. the l, m and s segment-based min ... | 2006 | 16630639 |
| midzonal lesions in yellow fever: a specific pattern of liver injury caused by direct virus action and in situ inflammatory response. | yellow fever is an acute infectious, non-contagious disease characterized by intense vasculopathy and lesions in different organs. in the liver, one of the main targets of the virus, the infection induces a characteristic midzonal injury characterized by hepatocyte necrosis, apoptosis and steatosis. this characteristics pattern of liver injury in yellow fever is also observed in conditions of low-flow hypoxia and other infections such as dengue and rift valley fever. there are no reports in the ... | 2006 | 16650626 |
| potential arbovirus emergence and implications for the united kingdom. | arboviruses have evolved a number of strategies to survive environmental challenges. this review examines the factors that may determine arbovirus emergence, provides examples of arboviruses that have emerged into new habitats, reviews the arbovirus situation in western europe in detail, discusses potential arthropod vectors, and attempts to predict the risk for arbovirus emergence in the united kingdom. we conclude that climate change is probably the most important requirement for the emergence ... | 2006 | 16704800 |
| risk of a rift valley fever epidemic at the haj in mecca, saudi arabia. | rift valley fever (rvf) is a zoonotic disease that affects both humans and domestic animals. in humans, it can cause a fatal haemorrhagic fever disease. when domestic animals such as sheep, goats, camels and cattle are infected, the infection may or may not be accompanied by clinical signs of disease. both sub-clinical and clinically affected animals present a hazard as a source of infection for humans. the risk of infection is greatest at the time of killing, when aerosols of infected blood may ... | 2006 | 16796043 |
| protective immune responses induced by different recombinant vaccine regimes to rift valley fever. | the glycoprotein (gp) and nucleocapsid (nc) genes of rift valley fever virus (rvfv) were expressed in different expression systems and were evaluated for their ability to protect mice from virulent challenge using a prime-boost regime. mice vaccinated with a lumpy skin disease virus-vectored recombinant vaccine (rlsdv-rvfv) expressing the two rvfv glycoproteins (g1 and g2) developed neutralising antibodies and were fully protected when challenged, as were those vaccinated with a crude extract of ... | 2006 | 16870311 |
| nsm and 78-kilodalton proteins of rift valley fever virus are nonessential for viral replication in cell culture. | rift valley fever viruses carrying mutations of the m gene preglycoprotein region, one lacking nsm protein expression, one lacking 78-kda protein expression, and one lacking expression of both proteins, were compared in cell culture. all of the mutants and their parent virus produced plaques with similar sizes and morphologies in vero e6 cells and had similar growth kinetics in vero, c6/36, and mrc5 cells, demonstrating that the nsm and 78-kda proteins were not needed for the virus to replicate ... | 2006 | 16873285 |
| development and characterization of a rift valley fever virus cell-cell fusion assay using alphavirus replicon vectors. | rift valley fever virus (rvfv), a member of the phlebovirus genus in the bunyaviridae family, is transmitted by mosquitoes and infects both humans and domestic animals, particularly cattle and sheep. since primary rvfv strains must be handled in bsl-3+ or bsl-4 facilities, a rvfv cell-cell fusion assay will facilitate the investigation of rvfv glycoprotein function under bsl-2 conditions. as for other members of the bunyaviridae family, rvfv glycoproteins are targeted to the golgi, where the vir ... | 2006 | 16945399 |
| production of monoclonal antibodies against rift valley fever virus application for rapid diagnosis tests (virus detection and elisa) in human sera. | this paper describes the production and characterization of rvfv monoclonal antibodies. the characteristics of 32 out of 55 elisa and/or ifa positive monoclonal antibodies were determined, including the rvfv components against which they are directed. one monoclonal antibody recognized the nucleoprotein, 15 the gc and 16 the gn. among the latter ones, five monoclonal antibodies possess another specificity and recognized both gn and either the nucleoprotein (four of them) or the nss protein (one) ... | 2006 | 16102851 |
| developing global climate anomalies suggest potential disease risks for 2006-2007. | el niño/southern oscillation (enso) related climate anomalies have been shown to have an impact on infectious disease outbreaks. the climate prediction center of the national oceanic and atmospheric administration (noaa/cpc) has recently issued an unscheduled el niño advisory, indicating that warmer than normal sea surface temperatures across the equatorial eastern pacific may have pronounced impacts on global tropical precipitation patterns extending into the northern hemisphere particularly ov ... | 2006 | 17194307 |
| the persistence of rift valley fever in the jazan region of saudi arabia. | a survey was conducted in the jazan region of saudi arabia to investigate the presence of rift valley fever (rvf) in sheep and goats, by clinical identification of suspected herds and detection of immunoglobulin m (igm) antibodies to rvf virus. the level of herd immunity was identified by detecting immunoglobulin g (igg) antibodies. rift valley fever was diagnosed in six out of eight districts included in the survey. twenty-two animals from 17 herds tested positive for the presence of igm antibo ... | 2006 | 17361776 |
| factors associated with rift valley fever in south-west saudi arabia. | the authors undertook a study of environmental and animal risk factors associated with rift valley fever (rvf) in south-west saudi arabia. an enzyme-linked immunosorbent assay was used to detect the presence of immunoglobulin m (igm) and immunoglobulin g (igg) antibodies against the rvf virus in serum samples from sentinel animals. in addition, a further 32 known igm-positive serum samples were tested using the reverse transcription polymerase chain reaction (rt-pcr) to detect the rvf virus geno ... | 2006 | 17361777 |
| rift valley fever virus lacking nsm proteins retains high virulence in vivo and may provide a model of human delayed onset neurologic disease. | rift valley fever virus is a significant human and veterinary pathogen responsible for explosive outbreaks throughout africa and the arabian peninsula. severe acute disease in humans includes rapid onset hepatic disease and hemorrhagic fever or delayed onset encephalitis. a highly efficient reverse genetics system was developed which allowed generation of recombinant rvf viruses to assess the role of nsm protein in virulence in a rat model in which wild-type rvf virus strain zh501 (wt-zh501) res ... | 2007 | 17412386 |
| spectrum of rift valley fever virus transmission in kenya: insights from three distinct regions. | rift valley fever virus (rvfv) is an emerging pathogen that maintains high biodefense priority based on its threat to livestock, its ability to cause human hemorrhagic fever, and its potential for aerosol spread. to define the range of human transmission during inter-epidemic and epidemic periods in kenya, we tested archived sera from defined populations (n = 1,263) for anti-rvfv igg by elisa and plaque reduction neutralization testing. rvfv seroprevalence was 10.8% overall and varied significan ... | 2007 | 17488893 |
| short report: efficient oral infection of culex pipiens quinquefasciatus by rift valley fever virus using a cotton stick support. | transmission experiments are essential to assess vector competence. in an attempt to study rift valley fever virus (rvfv) transmission in its arthropod vector, disseminated infection rates were measured in culex pipiens quinquefasciatus exposed to clone 13, an avirulent variant of rvfv. we compared the classic system of glass feeders covered with different membranes (0-1%) with an alternative system in which a cotton stick is used as a support of a blood meal. the latter system showed the highes ... | 2007 | 17488899 |
| comparative analysis of the alphavirus-based vectors expressing rift valley fever virus glycoproteins. | during the last decade, alphaviruses became widely used for expression of heterologous genetic information and development of recombinant vaccines against a variety of human and animal pathogens. in this study, we compared a number of vectors based on the genome of sindbis (sinv) and venezuelan equine encephalitis (veev) viruses for their ability to express the rift valley fever virus (rvfv) envelope glycoprotein gn and induce a protective immune response against rvfv infection. our results sugg ... | 2007 | 17507072 |
| characterization of rift valley fever virus transcriptional terminations. | rift valley fever virus (rvfv) (genus phlebovirus, family bunyaviridae) has a tripartite negative-strand genome and causes a mosquito-borne disease among humans and livestock in sub-saharan african and arabian peninsula countries. phlebovirus l, m, and n mrnas are synthesized from the virus-sense rna segments, while nss mrna is transcribed from the anti-virus-sense s segment. the present study determined the 3' termini of all rvfv mrnas. the 3' termini of n and nss mrnas were mapped within the s ... | 2007 | 17537856 |
| antigenic and genetic relationships among rift valley fever virus and other selected members of the genus phlebovirus (bunyaviridae). | preliminary serologic data indicated that two south american phleboviruses (belterra virus [beltv] and icoaraci virus [icov]) may be related to rift valley fever virus (rvfv), an african phlebovirus that causes severe hepatitis and hemorrhagic fever in humans. to further define this relationship and to investigate the underlying genetic basis, comparative serologic and genetic sequence analyses were performed with rvfv and five other new world phleboviruses (icov, beltv, salobo virus, joa virus, ... | 2007 | 17556635 |