Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| human outbreak of st. louis encephalitis detected in argentina, 2005. | an outbreak of flavivirus encephalitis occurred in 2005 in córdoba province, argentina. | 2008 | 18249032 |
| reliable detection of st. louis encephalitis virus by rt-nested pcr. | st. louis encephalitis virus (slev) is a re-emerging arbovirus in south america, with reported cases in humans in argentina and brazil. this fact indicates that there is an urgent need to increase the current knowledge about this virus in order to control and prevent future cases. exhaustive epidemiological and laboratory investigation is required to ensure fast, accurate identification of the viral agent and allow prompt surveillance action by health authorities. herein, we report the developme ... | 2008 | 18208760 |
| evaluation of the langat/dengue 4 chimeric virus as a live attenuated tick-borne encephalitis vaccine for safety and immunogenicity in healthy adult volunteers. | with the steady rise in tick-borne encephalitis virus (tbev) infections in europe, development of a live attenuated vaccine that will generate long-lasting immunity would be of considerable benefit. a chimeric flavivirus, designated lgt/den4, was previously constructed to have a genome containing the prm and e protein genes of langat virus (lgt), a naturally attenuated member of the tbev complex, and the remaining genetic sequences derived from dengue 4 virus (den4). lgt/den4 was highly attenuat ... | 2008 | 18207289 |
| defining the levels of secreted non-structural protein ns1 after west nile virus infection in cell culture and mice. | infection with west nile virus (wnv) causes a febrile illness that can progress to meningitis or encephalitis, primarily in humans that are immunocompromised or elderly. for successful treatment of wnv infection, accurate and timely diagnosis is essential. previous studies have suggested that the flavivirus non-structural protein ns1, a highly conserved and secreted glycoprotein, is a candidate protein for rapid diagnosis. herein, we developed a capture enzyme-linked immunosorbent assay (elisa) ... | 2008 | 18205232 |
| viral meningitis. | 0 | 18174598 | |
| evaluation of an indirect immunofluorescence assay for detection of immunoglobulin m (igm) and igg antibodies against yellow fever virus. | the first commercial indirect immunofluorescence assay (ifa) using euroimmun biochip technology was evaluated for the serodiagnosis of immunoglobulin g (igg) and igm antibodies against yellow fever virus (yfv) and was compared with the plaque reduction neutralization test (prnt), which is currently the gold standard test for yfv. an overall correlation between the tests of 98.7% was established based on the analysis of 150 sera from individuals after vaccination with the 17d yellow fever vaccine ... | 2008 | 18045884 |
| exposure of red knots (calidris canutus rufa) to select avian pathogens; patagonia, argentina. | as part of the shorebird surveillance, red knots (calidris canutus rufa) were sampled in two patagonian sites in argentina, río grande and san antonio oeste, during 2005-2006. cloacal swabs and serum samples were collected from 156 birds and tested by virus isolation (newcastle disease virus), polymerase chain reaction (pcr; avian influenza virus and plasmodium/hemoproteus), and for antibodies to st. louis encephalitis virus. all test results were negative. | 2007 | 17984283 |
| effect of hurricane katrina on arboviral disease transmission. | 2007 | 17953117 | |
| detection and typing of human herpesvirus 6 by molecular methods in specimens from patients diagnosed with encephalitis or meningitis. | human herpesvirus 6 (hhv-6) was detected in specimens from patients hospitalized with symptoms of encephalitis or meningitis. a real-time pcr assay was developed which has a linear dynamic range of 5 to 5 x 10(6) copies of hhv-6 and a sensitivity of five gene copies per reaction. while the assay detects both subtypes, hhv-6a and hhv-6b, it is specific and does not cross-react with a selected specificity panel. a total of 1,482 patient specimens, which were collected between 2003 and 2007, were t ... | 2007 | 17942643 |
| mosquitoes inoculate high doses of west nile virus as they probe and feed on live hosts. | west nile virus (wnv) is transmitted to vertebrate hosts by mosquitoes as they take a blood meal. the amount of wnv inoculated by mosquitoes as they feed on a live host is not known. previous estimates of the amount of wnv inoculated by mosquitoes (10(1.2)-10(4.3) pfu) were based on in vitro assays that do not allow mosquitoes to probe or feed naturally. here, we developed an in vivo assay to determine the amount of wnv inoculated by mosquitoes as they probe and feed on peripheral tissues of a m ... | 2007 | 17941708 |
| application of modified shell vial culture procedure for arbovirus detection. | the isolation of arboviruses from patient's low titer sera can be difficult. here we compared the detection efficiency of dengue (den), yellow fever (yf), saint louis encephalitis (sle), west nile (wn), ilheus (ilh), group c (gc), oropouche (oro), mayaro (may) and venezuela encephalitis equine (vee) viruses using a modified shell vial culture (msvc) protocol to a standard cell culture (scc) protocol. first the msvc and scc protocols were compared using five dilutions for each of the following st ... | 2007 | 17940598 |
| risk factors associated with st. louis encephalitis seroprevalence in two populations from córdoba, argentina. | st. louis encephalitis virus (slev) is endemic in argentina. the first outbreak was recorded in córdoba during the late summer of 2005. this study analyzes the association between social and demographic factors and other variables related to exposure to mosquitoes with slev infection in 264 individuals who attended two health centers in the city of córdoba during the period december 2004-january 2005. multiple logistic regression models were used to estimate the risk coefficients. the seropreval ... | 2007 | 17915268 |
| the isolation of the st. louis encephalitis virus from chicken mites (dermanyssus gallinae) in nature. | 1944 | 17835066 | |
| japanese b encephalitis virus: its differentiation from st. louis encephalitis virus and relationship to louping-ill virus. | 1937 | 17832643 | |
| interference between st. louis encephalitis virus and equine encephalomyelitis virus (western type) in the chick embryo. | interference between two unrelated viruses is reported. equine encephalomyelitis virus grows only to a limited degree, if at all, when injected into chick embryos in which st. louis encephalitis virus is being propagated. | 1944 | 17815105 |
| differentiation of west nile and st. louis encephalitis virus infections by use of noninfectious virus-like particles with reduced cross-reactivity. | differential diagnosis of st. louis encephalitis virus (slev) and west nile virus (wnv) infections can be complicated due to the high degree of cross-reactivity observed in most serodiagnostic assays. in an effort to provide a more specific diagnostic test, we developed virus-like particle (vlp) antigens with reduced cross-reactivity for both slev and wnv by identifying and mutating envelope protein amino acids within the cross-reactive epitopes of vlp expression plasmids. to determine the serod ... | 2007 | 17715375 |
| comparison of immune responses of brown-headed cowbird and related blackbirds to west nile and other mosquito-borne encephalitis viruses. | the rapid geographic spread of west nile virus (family flaviviridae, genus flavivirus, wnv) across the united states has stimulated interest in comparative host infection studies to delineate competent avian hosts critical for viral amplification. we compared the host competence of four taxonomically related blackbird species (icteridae) after experimental infection with wnv and with two endemic, mosquito-borne encephalitis viruses, western equine encephalomyelitis virus (family togaviridae, gen ... | 2007 | 17699082 |
| adaptation of two flaviviruses results in differences in genetic heterogeneity and virus adaptability. | west nile virus (wnv) is a mosquito-borne flavivirus that was first introduced into the usa in the new york city area in 1999. since its introduction, wnv has steadily increased both its host and geographical ranges. outbreaks of the closely related flavivirus, st. louis encephalitis virus (slev), occur in the usa periodically, but levels of activity and host range are more restricted than those of wnv. understanding the selective pressures that drive arbovirus adaptation and evolution in their ... | 2007 | 17698648 |
| reduced infection in mosquitoes exposed to blood meals containing previously frozen flaviviruses. | the increased difficulty and expense of using live animals for delivering infectious blood meals in arthropod-borne virus vector competence experiments has resulted in an increase in the use of artificial feeding systems. compared to live hosts, artificial systems require higher viral titers to attain mosquito infection, thereby limiting the utility of such systems with low or moderate titer virus stocks. based on the report that freshly propagated virus is more infectious than previously frozen ... | 2007 | 17686541 |
| simultaneous infection by denv-3 and slev in brazil. | 2007 | 17658293 | |
| western equine encephalitis in saskatchewan reptiles and amphibians, 1961-1963. | western equine encephalitis (wee) antibodies were found in blood samples from garter snakes and leopard frogs collected in saskatchewan but wee virus was not recovered from any of the specimens. evidence of natural wee infection in snakes was found in 8 different localities while in frogs in two only. experimentally, garter snakes were readily infected and developed a high, relatively sustained viremia without signs of disease. after experimental exposure, viremia persisted regularly for 10 to 1 ... | 1964 | 17649511 |
| experimental transmission of west nile virus by culex nigripalpus from honduras. | as a result of concerns regarding the geographic spread of west nile virus (wnv) to central america, we evaluated the potential for honduran culex nigripalpus theobald to transmit this virus. we tested individual mosquitoes captured in olancho province, honduras, in september 2003. mosquitoes were allowed to feed on 2- to 4- day-old chickens previously inoculated with a new york strain (crow 397-99) of wnv. infection rates in cx. nigripalpus ranged from 81%-96% after feeding on chickens with vir ... | 2007 | 17627449 |
| flavivirus serology by western blot analysis. | the spread of west nile virus (wnv) across the united states into areas with endemic flavivirus activity has complicated serologic surveillance of seasonal virus activity and diagnosis of infected individuals. here we describe preliminary results from a comparison of serologic assays for flaviviruses: the reference plaque reduction neutralization test (prnt), enzyme immunoassay (eia), and a western blot (wb) in which crude viral lysates were electrophoresed and blotted onto nitrocellulose. human ... | 2007 | 17620648 |
| a real-time taqman polymerase chain reaction for the identification of culex vectors of west nile and saint louis encephalitis viruses in north america. | in north america, west nile and st. louis encephalitis viruses have been detected in a wide range of vector species, but the majority of isolations continue to be from pools of mixed mosquitoes in the culex subgenus culex. unfortunately, the morphologic identification of these important disease vectors is often difficult, particularly in regions of sympatry. we developed a sensitive real-time taqman polymerase chain reaction assay that allows reliable identification of culex mosquitoes including ... | 2007 | 17620631 |
| validation of a microsphere-based immunoassay for detection of anti-west nile virus and anti-st. louis encephalitis virus immunoglobulin m antibodies. | a microsphere-based immunoassay (mia) was previously developed that is capable of determining the presence of anti-west nile (wn) virus or anti-st. louis encephalitis (sle) virus immunoglobulin m (igm) antibodies in human serum or cerebrospinal fluid. the original data set on which the classification rules were based comprised 491 serum specimens obtained from the serum bank at the division of vector-borne infectious diseases of the centers for disease control and prevention (dvbid). the classif ... | 2007 | 17609393 |
| epitope-blocking enzyme-linked immunosorbent assay to differentiate west nile virus from japanese encephalitis virus infections in equine sera. | west nile virus (wnv) is now widely distributed worldwide, except in most areas of asia where japanese encephalitis virus (jev) is distributed. considering the movement and migration of reservoir birds, there is concern that wnv may be introduced in asian countries. although manuals and guidelines for serological tests have been created in japan in preparedness for the introduction of wnv, differential diagnosis between wnv and jev may be complicated by antigenic cross-reactivities between these ... | 2007 | 17596430 |
| a multiplexed taqman assay for the detection of arthropod-borne flaviviruses. | arboviruses in the genus flavivirus are major causes of human disease worldwide, and yet they are widely under reported. this is partially due to the classical methods of detection, using virologic or immunologic techniques, which typically lack sensitivity and specificity or require biological containment facilities in order to manipulate infectious cultures. molecular detection assays based on broadly reactive (degenerate) primers also tend to have differential and lower sensitivity for many f ... | 2007 | 17583360 |
| west nile virus, venezuela. | 2007 | 17561567 | |
| depression after infection with west nile virus. | previous reports have noted depression after west nile virus (wnv) infection. we further measured this outcome and found that 31% of patients reported new-onset depression and 75% of these had center for epidemiologic studies depression scores indicative of mild-to-severe depression. physicians should be aware of neuropsychiatric consequences of wnv in patients. | 2007 | 17552106 |
| in vitro resistance selection and in vivo efficacy of morpholino oligomers against west nile virus. | we characterize in vitro resistance to and demonstrate the in vivo efficacy of two antisense phosphorodiamidate morpholino oligomers (pmos) against west nile virus (wnv). both pmos were conjugated with an arg-rich peptide. one peptide-conjugated pmo (ppmo) binds to the 5' terminus of the viral genome (5'-end ppmo); the other targets an essential 3' rna element required for genome cyclization (3' conserved sequence i [3' csi] ppmo). the 3' csi ppmo displayed a broad spectrum of antiflavivirus act ... | 2007 | 17485503 |
| mosquitoborne infections after hurricane jeanne, haiti, 2004. | after hurricane jeanne in september 2004, surveillance for mosquitoborne diseases in gonaïves, haiti, identified 3 patients with malaria, 2 with acute dengue infections, and 2 with acute west nile virus infections among 116 febrile patients. these are the first reported human west nile virus infections on the island of hispaniola. | 2007 | 17479899 |
| surveillance for west nile virus in clinic-admitted raptors, colorado. | in 2005, 13.5% of clinic-admitted raptors in northern colorado tested positive for west nile virus (wnv). clinic-admitted-raptor surveillance detected wnv activity nearly 14 weeks earlier than other surveillance systems. wnv surveillance using live raptor admissions to rehabilitation clinics may offer a novel surveillance method and should be considered along with other techniques already in use. | 2007 | 17479898 |
| identification of dengue virus in respiratory specimens from a patient who had recently traveled from a region where dengue virus infection is endemic. | dengue is the most important arthropod-borne viral disease, and it is a major public health problem in subtropical and tropical regions. the virus is transmitted to humans by the bite of infected female mosquitoes of the genus aedes. the global resurgence of dengue is thought to be due to failure to control the aedes populations, uncontrolled urbanization, population growth, climate change, and increased airplane travel. in this paper we describe the methods used to detect dengue virus infection ... | 2007 | 17376878 |
| saint louis encephalitis virus, brazil. | 2007 | 17370543 | |
| alkhurma hemorrhagic fever virus in ornithodoros savignyi ticks. | evidence for the tickborne nature of alkhurma hemorrhagic fever virus (ahfv) is indirect because ahfv has not been detected in arthropods. one ornithodoros savignyi tick from saudi arabia contained ahfv rna. this is the first direct evidence that ahfv is a tickborne flavivirus and confirms the association between human ahfv cases and tickbite history. | 2007 | 17370534 |
| panmicrobial oligonucleotide array for diagnosis of infectious diseases. | to facilitate rapid, unbiased, differential diagnosis of infectious diseases, we designed greenechippm, a panmicrobial microarray comprising 29,455 sixty-mer oligonucleotide probes for vertebrate viruses, bacteria, fungi, and parasites. methods for nucleic acid preparation, random primed pcr amplification, and labeling were optimized to allow the sensitivity required for application with nucleic acid extracted from clinical materials and cultured isolates. analysis of nasopharyngeal aspirates, b ... | 2007 | 17370518 |
| association of west nile virus illness and urban landscapes in chicago and detroit. | west nile virus infection in humans in urban areas of the midwestern united states has exhibited strong spatial clustering during epidemic years. we derived urban landscape classes from the physical and socio-economic factors hypothesized to be associated with west nile virus (wnv) transmission and compared those to human cases of illness in 2002 in chicago and detroit. the objectives were to improve understanding of human exposure to virus-infected mosquitoes in the urban context, and to assess ... | 2007 | 17352825 |
| west nile virus antibody prevalence in wild mammals, southern wisconsin. | twenty percent prevalence of west nile virus antibody was found in free-ranging medium-sized wisconsin mammals. no significant differences were noted in antibody prevalence with regard to sex, age, month of collection, or species. our results suggest a similar route of infection in these mammals. | 2006 | 17326959 |
| serologic evidence of widespread everglades virus activity in dogs, florida. | everglades virus (evev), an alphavirus in the venezuelan equine encephalitis complex, circulates among rodents and vector mosquitoes in florida and occasionally infects humans. it causes febrile disease, sometimes accompanied by neurologic manifestations. although previous surveys showed high seroprevalence in humans, evev infections may be underdiagnosed because the disease is not severe enough to warrant a clinic visit or the undifferentiated presentations complicate diagnosis. documented evev ... | 2006 | 17326938 |
| vector competence of culiseta incidens and culex thriambus for west nile virus. | the vector competence of culiseta incidens (thomson) and culex thriambus dyar for west nile virus (wnv) were compared to cx. quinquefasciatus say or cx. tarsalis coquillett and cx. stigmatasoma dyar collected concurrently in california. culiseta incidens were less susceptible to oral infection than cx. quinquefasciatus, but transmitted virus at a significantly higher rate, thereby yielding comparable population transmission rates. culex thriambus was equally susceptible to oral infection and tra ... | 2006 | 17304934 |
| chronic st. louis encephalitis virus infection in the golden hamster (mesocricetus auratus). | to further study the phenomenon of flavivirus persistent infection, golden hamsters (mesocricetus auratus) were inoculated intraperitoneally with a low pathogenicity strain of st. louis encephalitis virus (slev). after inoculation, the animals remained asymptomatic and developed high levels of specific neutralizing antibodies in their sera. however, about one half of the hamsters continued to shed infectious slev in their urine for prolonged periods of time. by co-cultivation, slev was recovered ... | 2007 | 17297039 |
| genotype iii saint louis encephalitis virus outbreak, argentina, 2005. | twenty-six years after it was last detected, saint louis encephalitis virus (slev) genotype iii reemerged in 2005 in c6rdoba, argentina, where it caused an outbreak. two genotype iii slev strains were isolated from culex quinquefasciatus. a 71.43% prevalence for neutralizing antibodies was found in domestic fowl in the homestead of a patient with encephalitis. | 2006 | 17283629 |
| unexpected altered specificity is responsible for st. louis encephalitis virus recombinant protease autoproteolysis. | we report herein the study of the cleavage fragments generated by autoproteolysis of the st. louis encephalitis virus recombinant protease. the cleavage sites leading to truncated forms were identified by microsequencing, which revealed an unexpected altered specificity of the recombinant proteinase towards unusual sequences. | 2007 | 17266653 |
| characterization of minaçu virus (reoviridae: orbivirus) and pathological changes in experimentally infected newborn mice. | minaçu virus was isolated from ochlerotatus scapularis (diptera: culicidae) in minaçu, goiás state, brazil, in 1996. in attempting characterization of virus serological (hemagluttination inhibition, hi; indirect immunofluorescence assay, ifa), physicochemical [test for deoxycholate acid (dca) sensitivity; polyacrylamide gel electrophoresis (page)] tests and ultrastructural studies were made. virus was also assayed in suckling mice after intracerebral inoculation of 0.02 ml and in vero and c6/36 ... | 2007 | 17244340 |
| west nile virus isolation from equines in argentina, 2006. | west nile virus (wnv) was isolated from the brains of 3 horses that died from encephalitis in february 2006. the horses were from different farms in central argentina and had not traveled outside the country. this is the first isolation of wnv in south america. | 2006 | 17176571 |
| mutation analysis of the fusion domain region of st. louis encephalitis virus envelope protein. | the immune response to flavivirus infections produces both species-specific and flavivirus cross-reactive antibodies. the presence of cross-reactive antibodies complicates serodiagnosis of flavivirus infections, especially secondary infections caused by a heterologous virus. a successful public health response to the growing global threat posed by flaviviruses necessitates the development of virus-specific diagnostic antigens. the flavivirus envelope (e) glycoprotein is the principle antigen sti ... | 2007 | 17157348 |
| monoclonal antibody-based competitive enzyme-linked immunosorbent assay for detecting and quantifying west nile virus-neutralizing antibodies in horse sera. | a rapid immunoassay for detecting and quantifying west nile virus (wnv)-neutralizing antibodies in sera was developed as an alternative to the plaque reduction neutralization test (prnt), the gold standard test for wnv. the assay is a competitive, enzyme-linked immunosorbent assay using neutralizing monoclonal antibody 5e8 (nt-elisa). a cutoff percent inhibition (pi) value of 35% (mean pi plus 3 standard deviations), with a specificity of 99%, was established based on analysis of 246 serum sampl ... | 2007 | 17135450 |
| development of multiplex real-time reverse transcriptase pcr assays for detecting eight medically important flaviviruses in mosquitoes. | a multiplex real-time reverse transcriptase pcr has been developed for the rapid detection and identification of eight medically important flaviviruses from laboratory-reared, virus-infected mosquito pools. the method used involves the gene-specific amplification of yellow fever virus (yfv), japanese encephalitis virus (jev), west nile virus (wnv), st. louis encephalitis virus (slev), and dengue virus (denv) serotypes 1 to 4 (denv-1 to denv-4, respectively) by use of the flavivirus consensus amp ... | 2007 | 17108075 |
| west nile virus infection in commercial waterfowl operation, wisconsin. | a west nile virus (wnv) outbreak occurred at a commercial waterfowl operation in wisconsin in 2005. retrospective analysis of dead and live birds was conducted. wnv was detected by pcr in 84.1% of 88 dead birds; neutralizing antibodies were found in 14 of 30 randomly sampled asymptomatic or recovered birds. | 2006 | 17073102 |
| antibody recognition and neutralization determinants on domains i and ii of west nile virus envelope protein. | previous studies have demonstrated that monoclonal antibodies (mabs) against an epitope on the lateral surface of domain iii (diii) of the west nile virus (wnv) envelope (e) strongly protect against infection in animals. herein, we observed significantly less efficient neutralization by 89 mabs that recognized domain i (di) or ii (dii) of wnv e protein. moreover, in cells expressing fc gamma receptors, many of the di- and dii-specific mabs enhanced infection over a broad range of concentrations. ... | 2006 | 17035317 |
| demographic and spatial analysis of west nile virus and st. louis encephalitis in houston, texas. | this descriptive prevalence study describes the relationships between mosquito density and the presence of arboviruses (in mosquitoes and humans) with various socioeconomic and environmental factors present near the time of teh arbovirus outbreak in harris county, texas, in 2002. this study suggests that mosquito density increased if the trap was located in an area with a large number of containers that may inadvertently retain rainwater (p = 0.056). when considering only virus-positive mosquito ... | 2006 | 17019771 |
| role of california (callipepla californica) and gambel's (callipepla gambelii) quail in the ecology of mosquito-borne encephalitis viruses in california, usa. | gambel's and california quail were infected repeatedly whenever western equine encephalomyelitis virus (weev), st. louis encephalitis virus (slev), and (wnv) west nile virus were active during summer in california. the timing of virus appearance and quail infection coincided well with the appearance of chicks in nature, leading us to hypothesize that large coveys containing these non-immune birds could be important in focal virus amplification in rural settings. however, experimental infection s ... | 2006 | 16989564 |
| cryptic properties of a cluster of dominant flavivirus cross-reactive antigenic sites. | a number of flaviviruses are important human pathogens, including yellow fever, dengue, west nile, japanese encephalitis, and tick-borne encephalitis (tbe) viruses. infection with or immunization against any of these viruses induces a subset of antibodies that are broadly flavivirus cross-reactive but do not exhibit significant cross-neutralization. nevertheless, these antibodies can efficiently bind to the major envelope protein (e), which is the main target of neutralizing and protective antib ... | 2006 | 16973559 |
| previous infection with west nile or st. louis encephalitis viruses provides cross protection during reinfection in house finches. | house finches are competent hosts for both west nile and st. louis encephalitis viruses and frequently become infected during outbreaks. in the current study, house finches were infected initially with either west nile or st. louis encephalitis viruses and then challenged 6 weeks post infection with either homologous or heterologous viruses. although mortality rates were high during initial infection with west nile virus, prior infection with either virus prevented mortality upon challenge with ... | 2006 | 16968925 |
| venezuelan equine encephalitis virus transmission and effect on pathogenesis. | quantifying the dose of an arbovirus transmitted by mosquitoes is essential for designing pathogenesis studies simulating natural infection of vertebrates. titration of saliva collected in vitro from infected mosquitoes may not accurately estimate titers transmitted during blood feeding, and infection by needle injection may affect vertebrate pathogenesis. we compared the amount of venezuelan equine encephalitis virus collected from the saliva of aedes taeniorhynchus to the amount injected into ... | 2006 | 16965696 |
| cell-specific adaptation of two flaviviruses following serial passage in mosquito cell culture. | west nile virus (wnv) is a mosquito-borne flavivirus that was introduced into the u.s. in the new york city area in 1999. despite its successful establishment and rapid spread in a naive environment, wnv has undergone limited evolution since its introduction. this evolutionary stability has been attributed to compromises made to permit alternating cycles of viral replication in vertebrate hosts and arthropod vectors. outbreaks of a close relative of wnv, st. louis encephalitis virus (slev), occu ... | 2007 | 16963095 |
| detection of antibodies to west nile virus in equine sera using microsphere immunoassay. | one hundred and ninety-one sera from horses that recently were exposed to west nile virus (wnv) by either vaccination or natural infection or that were not vaccinated and remained free of infection were used to evaluate fluorescent microsphere immunoassays (mias) incorporating recombinant wnv envelope protein (re) and recombinant nonstructural proteins (rns1, rns3, and rns5) for detection of equine antibodies to wnv. the re mia had a diagnostic sensitivity and specificity, respectively, of 99.3% ... | 2006 | 16921881 |
| west nile and st. louis encephalitis virus antibody seroconversion, prevalence, and persistence in naturally infected pig-tailed macaques (macaca nemestrina). | pig-tailed macaques (macaca nemestrina) naturally infected with west nile virus were monitored from 1999 to 2005 to determine virus-specific antibody seroconversion, prevalence, and persistence. antibodies persisted for up to 36 months, as detected by epitope-blocking enzyme-linked immunosorbent and hemagglutination inhibition assays. exposure to cocirculating st. louis encephalitis virus was evaluated by western blotting and immunofluorescence assays. | 2006 | 16760333 |
| west nile virus in horses, guatemala. | 2006 | 16752479 | |
| west nile virus infection in humans and horses, cuba. | a surveillance system to detect west nile virus (wnv) was established in cuba in 2002. wnv infection was confirmed by serologic assays in 4 asymptomatic horses and 3 humans with encephalitis in 2003 and 2004. these results are the first reported evidence of wnv activity in cuba. | 2006 | 16707068 |
| genetic characterization of st. louis encephalitis virus isolated from human in são paulo, brazil. | the molecular characterization of sph253157, a new strain of st. louis encephalitis virus (slev), isolated in 2004 from the first case of human infection recognized in the state of são paulo, brazil, is reported. the patient, presenting a febrile illness without neurological involvement, was hospitalized as a probable case of dengue fever. genomic rna was isolated from the supernatant of c6/36 cells infected with acute phase-serum specimen of the patient and the envelope gene was amplified by re ... | 2006 | 16699711 |
| nuclear localization of flavivirus rna synthesis in infected cells. | flaviviral replication is believed to be exclusively cytoplasmic, occurring within virus-induced membrane-bound replication complexes in the host cytoplasm. here we show that a significant proportion (20%) of the total rna-dependent rna polymerase (rdrp) activity from cells infected with west nile virus, japanese encephalitis virus (jev), and dengue virus is resident within the nucleus. consistent with this, the major replicase proteins ns3 and ns5 of jev also localized within the nucleus. ns5 w ... | 2006 | 16699025 |
| west nile virus antibodies in colombian horses. | 2005 | 16673523 | |
| a single tube rt-pcr assay for the detection of mosquito-borne flaviviruses. | mosquito-borne flaviviruses include several important agents of human disease and have provided striking examples of emerging infections. in this study we present the design and validation of a single tube rt-pcr assay using a pair of consensus primers for the detection of mosquito-borne flaviviruses. sequencing of the amplicons permits the species identification. the assay was validated using rna from the yellow fever virus vaccine strain and from representative strains of dengue viruses 1, 2, ... | 2006 | 16650488 |
| evaluation of commercial assays for detecting west nile virus antigen. | two commercially available west nile virus (wnv) detection assays (ramp wnv test, response biomedical corp., burnaby, british columbia, canada; and vectest wnv antigen assay, medical analysis systems, inc., camarillo, ca) were compared for sensitivity, specificity, and ability to detect wnv in field-collected mosquito pools. serially diluted stock seed wnv and st. louis encephalitis virus (slev) were used to determine sensitivity and specificity. the ramp wnv test detected wnv at concentrations ... | 2006 | 16646324 |
| a simple and rapid protein array based method for the simultaneous detection of biowarfare agents. | a protein chip has been developed that allows the simultaneous detection of a multitude of different biowarfare agents. the chip was developed for the arraytube platform providing a cheap and easy to handle technology solution that combines a microtube-integrated protein chip with the classical procedure of a sandwich-enzyme-linked immunosorbent assay and signal amplification by streptavidin-poly-horseradish peroxidase. specific immunoassays for staphylococcus enterotoxin b, ricin, venezuelan eq ... | 2006 | 16622830 |
| effects of temperature on the transmission of west nile virus by culex tarsalis (diptera: culicidae). | culex tarsalis coquillett females were infected with the ny99 strain of west nile virus (family flaviviridae, genus flavivirus, wnv) and then incubated under constant temperatures of 10-30 degrees c. at selected time intervals, transmission was attempted using an in vitro capillary tube assay. the median time from imbibing an infectious bloodmeal until infected females transmitted wnv (median extrinsic incubation period, eip50) was estimated by probit analysis. by regressing the eip rate (invers ... | 2006 | 16619616 |
| west nile virus antibodies in avian species of georgia, usa: 2000-2004. | west nile virus (wnv) was first isolated in the state of georgia in the summer of 2001. as amplifying hosts of wnv, avian species play an important role in the distribution and epidemiology of the virus. the objective of this study was to identify avian species that are locally involved as potential amplifying hosts of wnv and can serve as indicators of wnv transmission over the physiographic and land use variation present in the southeastern united states. avian serum samples (n=14,077) from 83 ... | 2006 | 16584328 |
| functional analysis of the tick-borne encephalitis virus cyclization elements indicates major differences between mosquito-borne and tick-borne flaviviruses. | the linear, positive-stranded rna genome of flaviviruses is thought to adopt a circularized conformation via interactions of short complementary sequence elements located within its terminal regions. this process of rna cyclization is a crucial precondition for rna replication. in the case of mosquito-borne flaviviruses, highly conserved cyclization sequences (cs) have been identified, and their functionality has been experimentally confirmed. here, we provide an experimental identification of c ... | 2006 | 16571826 |
| experimental transplacental transmission of st. louis encephalitis virus in mice. | transplacental infection of the mouse embryo with st. louis encephalitis (sle) virus was produced by injecting the mother with virus at various stages of gestation. intravenous or subcutaneous injection of the mother with 10(5.9) suckling mouse median lethal dose (smld(50)) of sle virus was found to infect 83 to 96% of the embryos when given at 4 days of gestation or later. injections at 6 days of gestation or earlier had little effect on the embryo although virus could be recovered at 10 days o ... | 1970 | 16557839 |
| geographic factors contributing to a high seroprevalence of west nile virus-specific antibodies in humans following an epidemic. | sera of 624 blood donors were evaluated to determine seroprevalence of west nile virus (wnv) antibodies following the 2003 wnv epidemic in nebraska. geographic factors contributing to differences in wnv seropositivity were evaluated. the overall prevalence of wnv in nebraska was higher than reported previously in other u.s. locations (9.5% wnv immunoglobulin g seroprevalence rate), with the highest prevalence identified in the western part of the state (19.7%), followed by the central (13.8%) an ... | 2006 | 16522771 |
| quantitation of flaviviruses by fluorescent focus assay. | an indirect immunofluorescence assay for quantitation of flaviviruses was developed as an alternative to the standard plaque assay. the assay was validated with west nile virus (wnv), st. louis encephalitis virus (slev), and dengue virus (denv) types 1-4. vero cells were plated in 8-well chamber slides, and infected with 10-fold serial dilutions of virus. about 1-3 days after infection, cells were fixed, incubated with specific monoclonal antibody, and stained with a secondary antibody labeled w ... | 2006 | 16510196 |
| association between hepatitis c virus and very-low-density lipoprotein (vldl)/ldl analyzed in iodixanol density gradients. | hepatitis c virus (hcv) rna circulates in the blood of persistently infected patients in lipoviroparticles (lvps), which are heterogeneous in density and associated with host lipoproteins and antibodies. the variability and lability of these virus-host complexes on fractionation has hindered our understanding of the structure of lvp and determination of the physicochemical properties of the hcv virion. in this study, hcv from an antibody-negative immunodeficient patient was analyzed using three ... | 2006 | 16474148 |
| serologic survey of select infectious diseases in coyotes and raccoons in nebraska. | to obtain data about select zoonotic and other infectious diseases in free-ranging predators in five ecoregions in nebraska, sera were collected from 67 coyotes (canis latrans) and 63 raccoons (procyon lotor) from november 2002 through january 2003. for coyotes, antibodies were detected against canine distemper virus (cdv, 61%), francisella tularensis (32%), rickettsia rickettsi (13%), and flaviviruses (48%). none of the coyote sera had antibodies to borrelia burgdorferi, brucella canis, or six ... | 2005 | 16456169 |
| changes in seroprevalence of west nile virus across illinois in free-ranging birds from 2001 through 2004. | of the 5,236 birds sampled for antibodies to west nile virus (wnv) in illinois from 2001 through 2004, 348 (6.6%) birds were seropositive. our multiple year surveillance identified several avian species that had particularly high percentages of seropositive individuals. the importance of these species in the enzootic and/or epizootic transmission of wnv is discussed relative to their regional abundance and literature on host competency. the species with the highest exposure rates to wnv differed ... | 2006 | 16407365 |
| modeling the impact of variable climatic factors on the crossover of culex restauns and culex pipiens (diptera: culicidae), vectors of west nile virus in illinois. | the aim of this study was to model the impact of temperature on the timing of the seasonal shift in relative proportion of culex restuans theobald and culex pipiens l. in illinois. the temporal pattern of west nile virus (wnv) and st. louis encephalitis virus transmission in the midwest exhibits a late summer to early fall peak in activity, which parallels the temporal increase in the abundance of cx. pipiens. the daily number of egg rafts oviposited by each species has been monitored at multipl ... | 2006 | 16407364 |
| [west nile fever]. | west nile virus was first detected in north america in 1999 and has spread throughout the united states and canada and into mexico and the caribbean. the cases of encephalitis in new york were diagnosed as saint louis encephalitis which was endemic in the north america. however, dead crows and dead flamingo were found around the same time in new york. american birds seldom die by saint louis encephalitis virus infection. according to viral isolation and sequencing of the genome, the causative ag ... | 2005 | 16363684 |
| host range, amplification and arboviral disease emergence. | etiologic agents of arboviral diseases are primarily zoonotic pathogens that are maintained in nature in cycles involving arthropod transmission among a variety of susceptible reservoir hosts. in the simplest form of human exposure, spillover occurs from the enzootic cycle when humans enter zoonotic foci and/or enzootic amplification increases circulation near humans. examples include eastern (eeev) and western equine encephalitis viruses (weev), as well as west nile (wnv), st. louis encephaliti ... | 2005 | 16358422 |
| west nile virus serosurveillance in iowa white-tailed deer (1999-2003). | sera from white-tailed deer (odocoileus virginianus) were collected in iowa during the winter months (1999-2003), 2 years before and after west nile virus (wnv) was first reported in iowa (2001), and were analyzed for antibodies to wnv. samples from 1999 to 2001 were antibody negative by blocking enzyme-linked immunosorbent assay (belisa) and plaque reduction neutralization test (prnt(90)). prevalence derived from belisa (2002, 12.7%; 2003, 11.2%) and wnv prnt(90) (2002, 7.9%; 2003, 8.5%) assays ... | 2005 | 16354809 |
| st. louis encephalitis virus: first isolation from a human in são paulo state, brazil. | this paper reports the isolation of st. louis encephalitis virus (slev) from a febrile human case suspected to be dengue, in são pedro, são paulo state. a mac-elisa done on the patient's acute and convalescent sera was inconclusive and hemagglutination inhibition test detected igg antibody for flaviviruses. an indirect immunofluorescent assay done on the c6/36 cell culture inoculated with the acute serum was positive for flaviviruses but negative when tested with dengue monoclonal antibodies. rn ... | 2005 | 16302112 |
| achieving operational hydrologic monitoring of mosquitoborne disease. | mosquitoes and mosquitoborne disease transmission are sensitive to hydrologic variability. if local hydrologic conditions can be monitored or modeled at the scales at which these conditions affect the population dynamics of vector mosquitoes and the diseases they transmit, a means for monitoring or modeling mosquito populations and mosquitoborne disease transmission may be realized. we review how hydrologic conditions have been associated with mosquito abundances and mosquitoborne disease transm ... | 2005 | 16229760 |
| nesting ardeid colonies are not a focus of elevated west nile virus activity in southern california. | a large nesting colony of ardeid birds at the finney-ramer wildlife refuge in imperial county, california, did not appear to be a focus of west nile virus (wnv) amplification during the summer of 2004. blood samples taken during june and july from 155 nestlings of four species of ardeid birds (cattle egrets, black-crowned night herons, great egrets, and snowy egrets) and five nestling double-crested cormorants yielded a single wnv isolation from a 3-week-old cattle egret. antibody was detected b ... | 2005 | 16187895 |
| west nile virus infection and serologic response among persons previously vaccinated against yellow fever and japanese encephalitis viruses. | it is hypothesized that previous heterologous flaviviral exposure may modulate clinical illness among persons infected with west nile virus (wnv). little is known about the serological response in such persons. in summer 2003, a wnv outbreak occurred in colorado, the location of the centers for disease control and prevention, division of vector-borne infectious diseases (dvbid). dvbid employees, most previously vaccinated with yellow fever virus (yfv) or japanese encephalitis virus (jev) vaccine ... | 2005 | 16011430 |
| comparative analysis of immunoglobulin m (igm) capture enzyme-linked immunosorbent assay using virus-like particles or virus-infected mouse brain antigens to detect igm antibody in sera from patients with evident flaviviral infections. | the use of immunoglobulin m (igm) antibody-capture enzyme-linked immunosorbent assay (mac-elisa) serves as a valuable tool for the diagnosis of acute flaviviral infections, since igm antibody titers are detectable early, peak at about 2 weeks postinfection, and subsequently decline to lower levels over the next few months. traditionally, virus-infected tissue culture or suckling mouse brain (smb) has been the source of viral antigens used in the assay. in an effort to provide a reliable source o ... | 2005 | 16000440 |
| avian host and mosquito (diptera: culicidae) vector competence determine the efficiency of west nile and st. louis encephalitis virus transmission. | the ability of the invading ny99 strain of west nile virus (wnv) to elicit an elevated viremia response in california passerine birds was critical for the effective infection of culex mosquitoes. of the bird species tested, western scrub jays, aphelocoma coerulescens, produced the highest viremia response, followed by house finches, carpodacus mexicanus, and house sparrows, passer domesticus. most likely, few mourning, zenaidura macroura, or common ground, columbina passerine, doves and no calif ... | 2005 | 15962789 |
| comparison of immunohistochemistry and virus isolation for diagnosis of west nile virus. | immunohistochemistry and virus isolation were performed on 1,057 birds. immunohistochemistry, virus isolation, or both found 325 birds to be west nile virus positive. of these, 271 were positive by both methods. these results indicate that virus isolation and immunohistochemistry are approximately equal in their ability to detect west nile virus. | 2005 | 15956415 |
| duplex microsphere-based immunoassay for detection of anti-west nile virus and anti-st. louis encephalitis virus immunoglobulin m antibodies. | west nile (wn) virus was introduced into the united states in 1999, when the first human cases of wn fever and encephalitis appeared in new york city. from there, the virus has spread throughout north america, in some areas cocirculating with the related flavivirus st. louis encephalitis (sle) virus. public health laboratories currently use an immunoglobulin m (igm) antibody capture enzyme-linked immunosorbent assay (mac-elisa) as a primary test for human serodiagnosis, followed by a confirmator ... | 2005 | 15879016 |
| characterization of neutralizing antibodies to west nile virus. | we produced nine monoclonal antibodies (mabs) directed against the west nile virus e glycoprotein using three different immunization strategies: inactivated virus, naked dna, and recombinant protein. most of the mabs bound to conformation dependent epitopes in domain iii of the e protein. four of the mabs neutralized wnv infection and bound to the same region of domain iii with high affinity. the neutralizing mabs were obtained from mice immunized with inactivated virus alone or in combination w ... | 2005 | 15866072 |
| molecular typing of west nile virus, dengue, and st. louis encephalitis using multiplex sequencing. | we report the development of an assay to simultaneously identify three of the clinically important flaviviruses (west nile virus, dengue, and st. louis encephalitis). this assay is based on the nucleotide sequence variations within a 266-bp region of the non-structural protein 5. further, based on the nucleotide variations in the same region of the non-structural protein 5, four of the present dengue serotypes were identified. to identify some of the subtypes of wnv we have developed a second as ... | 2005 | 15858138 |
| development of a humanized monoclonal antibody with therapeutic potential against west nile virus. | neutralization of west nile virus (wnv) in vivo correlates with the development of an antibody response against the viral envelope (e) protein. using random mutagenesis and yeast surface display, we defined individual contact residues of 14 newly generated monoclonal antibodies against domain iii of the wnv e protein. monoclonal antibodies that strongly neutralized wnv localized to a surface patch on the lateral face of domain iii. convalescent antibodies from individuals who had recovered from ... | 2005 | 15852016 |
| antibody response to culex tarsalis salivary gland antigens among sentinel chickens in california. | the arboviral surveillance program in california depends in part on sentinel chickens to detect western equine encephalomyelitis virus, st. louis encephalitis virus, and west nile virus activity. from 2000 through 2002, 1,578 serum specimens from 34 sentinel flocks in northern and southern california were tested for antibodies to culex tarsalis salivary gland antigens. sentinel chickens that were seropositive for mosquito salivary gland antigens were more likely to seroconvert to st. louis encep ... | 2005 | 15827292 |
| first report of west nile virus in mosquitoes from lubbock county, texas. | since july 2002, ongoing surveillance efforts have been conducted to determine potential vectors of west nile virus (wnv) and saint louis encephalitis virus (slev) in the mosquito population occurring in lubbock county, texas. adult mosquitoes collected in lubbock county during 2002 and 2003 represented 7 genera, with culex tarsalis and ochlerotatus sollicitans being the predominant species collected. mosquitoes were initially screened for wnv and slev by using the vectest antigen panel assay. p ... | 2005 | 15825772 |
| drought-induced amplification and epidemic transmission of west nile virus in southern florida. | we show that the spatial-temporal variability of human west nile (wn) cases and the transmission of west nile virus (wnv) to sentinel chickens are associated with the spatial-temporal variability of drought and wetting in southern florida. land surface wetness conditions at 52 sites in 31 counties in southern florida for 2001-2003 were simulated and compared with the occurrence of human wn cases and the transmission of wnv to sentinel chickens within these counties. both wnv transmission to sent ... | 2005 | 15799522 |
| duplex reverse transcription-pcr followed by nested pcr assays for detection and identification of brazilian alphaviruses and flaviviruses. | a new approach was developed for the rapid detection and identification of brazilian alphaviruses and flaviviruses. the methodology involves the genus-specific detection of alphavirus and flavivirus by a duplex reverse transcription-pcr (d-rt-pcr), followed by multiplex nested pcr (m-n-pcr) or nested pcr (n-pcr) assays for species-specific identification. by this protocol, 25 arboviruses were specifically detected and identified. detection levels between 10(1.3) and 10(3.5) 50% tissue culture in ... | 2005 | 15695666 |
| serologic evidence of west nile virus and st. louis encephalitis virus infections in white-tailed deer (odocoileus virginianus) from new jersey, 2001. | serum samples from 689 hunter-killed white-tailed deer (odocoileus virginianus) collected during the 2001 fall hunting season in new jersey were tested for neutralizing antibodies to west nile virus (wnv) and st. louis encephalitis virus (slev) by plaque-reduction neutralization tests. wnv-neutralizing antibodies were detected in six (0.9%) of the samples, and slev-neutralizing antibodies were found in 11 (1.6%) of the samples. we provide the first report of wnv infection in white-tailed deer. | 2004 | 15671740 |
| st. louis encephalitis in early infancy. | we describe a case of st. louis encephalitis in a 19-day-old infant who presented with fever and seizure activity. to our knowledge, this is the youngest case of st. louis encephalitis ever reported. | 2004 | 15602196 |
| construction of yellow fever/st. louis encephalitis chimeric virus and the use of chimeras as a diagnostic tool. | st. louis encephalitis (sle) and west nile (wn) flaviviruses are genetically closely related and cocirculate in the united states. virus neutralization tests provide the most specific means for serodiagnosis of infections with these viruses. however, use of wild-type sle and wn viral strains for laboratory testing is constrained by the biocontainment requirements. we constructed two highly attenuated yellow fever (yf) virus chimeras that contain the premembrane-envelope (prm-e) protein genes fro ... | 2004 | 15569798 |
| isolation of st. louis encephalitis virus from a killer whale. | we report the isolation of st. louis encephalitis (sle) virus from a mature male killer whale (orcinus orca). this represents the first isolation of sle virus from a marine mammal. the animal presented with reduced appetite, rapidly became lethargic and subsequently died. virus-induced cpe was observed in a dolphin cell line, sp-1k (atcc ccl 78), inoculated with brain, kidney, and lung tissues obtained at necropsy. electron microscopy of infected sp-1k cells revealed the presence of virions havi ... | 1993 | 15566723 |
| evaluation of a diagnostic algorithm using immunoglobulin m enzyme-linked immunosorbent assay to differentiate human west nile virus and st. louis encephalitis virus infections during the 2002 west nile virus epidemic in the united states. | a diagnostic algorithm was developed to differentiate between human infections of west nile virus (wnv) and st. louis encephalitis virus (slev) using positive-to-negative (p/n) ratios derived from the immunoglobulin m capture enzyme-linked immunosorbent assay (mac-elisa). to validate this algorithm, we tested 1,418 serum and cerebrospinal fluid (csf) samples from confirmed wnv and slev infections collected during the wnv epidemic of 2002 in the united states. wnv p/n-to-slev p/n ratios (w/s rati ... | 2004 | 15539517 |
| effect of dose on house finch infection with western equine encephalomyelitis and st. louis encephalitis viruses. | house finches, carpodacus mexicanus, were experimentally infected with high and standard doses of western equine encephalomyelitis virus (weev) or st. louis encephalitis virus (slev) to determine whether high doses would produce an elevated viremia response and a high frequency of chronic infections. finches inoculated with approximately100,000 plaque forming units (pfu) of weev or slev produced viremia and antibody responses similar to those in finches inoculated with approximately 100 pfu of w ... | 2004 | 15535631 |