| health assessment of free-ranging three-banded (tolypeutes matacus) and nine-banded (dasypus novemcinctus) armadillos in the gran chaco, bolivia. | the gran chaco, bolivia, has a total of seven species of armadillos with the three-banded (tolypeutes matacus) and nine-banded (dasypus novemcinctus) the most commonly hunted by the local isoseño-guarani people. armadillos are known carriers of zoonotic pathogens, including mycobacterium leprae, toxoplasma gondii, and trypanosoma cruzi; thus human handling and consumption of these species may have a significant public health impact. a health assessment that included physical examinations, hemato ... | 2009 | 19569470 |
| cellular inflammatory response to flaviviruses in the central nervous system of a primate host. | flaviviruses such as tick-borne encephalitis virus, japanese encephalitis virus, west nile virus, and st. louis encephalitis virus are important neurotropic human pathogens, typically causing a devastating and often fatal neuroinfection. flaviviruses induce neuroinflammation with typical features of viral encephalitides, including inflammatory cell infiltration, activation of microglia, and neuronal degeneration. development of safe and effective live-virus vaccines against neurotropic flaviviru ... | 2009 | 19581627 |
| prevalence of antibodies to west nile virus and other arboviruses among crested caracaras (caracara cheriway) in florida. | we documented the antibody prevalence to three arboviruses, st. louis encephalitis virus (slev), eastern equine encephalitis virus (eeev), and west nile virus (wnv), in crested caracaras (caracara cheriway; n = 80) in florida from 2007 to 2008. antibody prevalence to wnv was higher (9%) than for the other viruses. most seropositive birds were adults (< or =3 yr of age), with 55% of adults testing positive for antibodies to at least one virus. adults were significantly more likely to have antibod ... | 2009 | 19617494 |
| west nile virus infection alters midgut gene expression in culex pipiens quinquefasciatus say (diptera: culicidae). | alterations in gene expression in the midgut of female culex pipiens quinquefasciatus exposed to blood meals containing 6.8 logs plaque-forming units/ml of west nile virus (wnv) were studied by fluorescent differential display. twenty-six different cdnas exhibited reproducible differences after feeding on infected blood. of these, 21 cdnas showed an increase in expression, and 5 showed a decrease in expression as a result of wnv presence in the blood meal. genbank database searches showed that o ... | 2009 | 19635880 |
| environmental and biological factors influencing culex pipiens quinquefasciatus say (diptera: culicidae) vector competence for saint louis encephalitis virus. | complex interactions between environmental and biological factors influence the susceptibility of culex pipiens quinquefasciatus to st. louis encephalitis virus and could affect the epidemiology of virus transmission. similar interactions could have epidemiologic implications for other vector-virus systems. we conducted an experiment to examine four such factors in combination: mosquito age, extrinsic incubation temperature (eit), virus dose, and colony. the proportion of mosquitoes with body in ... | 2009 | 19635881 |
| phase 1 trial of the dengue virus type 4 vaccine candidate rden4{delta}30-4995 in healthy adult volunteers. | rden4delta30-4995 is a live attenuated dengue virus type 4 (denv4) vaccine candidate specifically designed as a further attenuated derivative of the rden4delta30 parent virus. in a previous study, 5 of 20 vaccinees who received 10(5) plaque-forming units (pfu) of rden4delta30 developed a transient elevation of the serum alanine aminotransferase (alt) level and an asymptomatic maculopapular rash developed in 10 of 20. in the current study, 28 healthy adult volunteers were randomized to receive 10 ... | 2009 | 19861619 |
| the limited neurotropic character of the encephalitis virus (st. louis type) in susceptible mice. | 1. st. louis encephalitis virus injected intracerebrally into susceptible mice multiplies there to reach a titre of 10(9) intracerebral lethal doses. it is found also in the blood in small amounts immediately following injection and preceding death. 2. injected intraperitoneally or subcutaneously the virus circulates in the blood for several hours and survives in the spleen for days. it does not multiply in the brain and cause encephalitis, however, unless overwhelming doses are injected or the ... | 1936 | 19870481 |
| experimental encephalitis (st. louis type) in mice with high inborn resistance : a chronic subclinical infection. | 1. st. louis encephalitis virus injected intracerebrally or intraperitoneally in maximum doses in resistant mice is distributed and is effective in a manner generally similar to that in susceptible mice. the minimum infecting dose is at least 1,000 times greater in resistant than susceptible mice and virus injected in the brain tends to remain at a relatively low titre, persist for a few days, and then disappear. 2. virus dropped in the nares is demonstrable and progresses in the brains of resis ... | 1936 | 19870508 |
| inheritance of resistance of mice to enteric bacterial and neurotropic virus infections. | under the conditions specified, there may be selected promptly from a hybrid stock of mice, of which 40 to 50 per cent die following a standard dose of b. enteritidis or st. louis encephalitis virus, lines in which as high as 95 per cent and as low as 15 per cent succumb. three lines,-one bacteria-susceptible-virus-susceptible, one bacteria-susceptible-virus-resistant, and one bacteria-resistant-virus-susceptible,-are regarded as remaining relatively stable after approximately twelve generations ... | 1937 | 19870600 |
| japanese b encephalitis virus: its differentiation from st. louis encephalitis virus and relationship to louping ill virus. | 1. japanese b encephalitis virus, obtained from japanese investigators, has proved virulent for mice and monkeys, confirming the reports from japan. it has also been found virulent for monkeys when instilled intranasally and for sheep when introduced intracerebrally or intranasally. 2. japanese b encephalitis virus has been differentiated from st. louis virus and found similar to louping ill virus according to its reactions in animal species. serologically, however, it is distinct. 3. japanese b ... | 1938 | 19870743 |
| immunity of mice following subcutaneous vaccination with st. louis encephalitis virus. | 1. susceptible mice injected subcutaneously or intraperitoneally with 15,000 intracerebral lethal doses of st. louis encephalitis virus develop an immunity in 4 to 7 days to 1,000 to 1,000,000 lethal doses given either intracerebrally or intranasally. 2. this immunity persists 4 to 6 weeks, then decreases gradually and disappears after 8 to 12 weeks. 3. more than 1,000 intracerebral doses of virus given as a vaccine do not materially increase the amount or duration of the immunity; less than 1,0 ... | 1938 | 19870770 |
| relation between degree of immunity of mice following vaccination with st. louis encephalitis virus and the titre of the protective antibodies of the serum. | vaccination of susceptible mice with st. louis encephalitis virus induced an acquired immunity to intracerebral inoculation which appeared within 1 week. when first demonstrable this immunity was at a very high level and it remained so for about 6 weeks, after which time it declined and disappeared completely between the 12th and 20th week after vaccination. humoral antibodies of significant titre could not be demonstrated during the first 6 weeks after vaccination when actual immunity to intrac ... | 1938 | 19870787 |
| effect of pregnancy upon the immunity of mice vaccinated against st. louis encephalitis virus. | 1. virgin and pregnant swiss mice are equally susceptible to intracerebral inoculation of st. louis encephalitis virus. 2. following subcutaneous vaccination with the st. louis virus, the great majority of virgin swiss mice become immune to subsequent intracerebral injection of 10,000 m.l.d. of the virus. 3. the majority of mice vaccinated during pregnancy do not become immune to even as little as 500 intracerebral m.l.d. of the virus. the depression of the ability to acquire immunity against th ... | 1939 | 19870862 |
| role of inborn resistance factors in mouse populations infected with bacillus enteritidis. | 1. under conditions in which mouse typhoid is allowed to spread naturally among herds of mice comprised of different proportions of individuals of innately high or low susceptibility: (a) 85 to 95 per cent of the innately susceptible succumb to mouse typhoid in contrast to less than 5 per cent of the innately resistant, regardless of whether either constitutes 25, 50, or 75 per cent of the population respectively. (b) the surviving population is therefore comprised largely of individuals known a ... | 1939 | 19870901 |
| comparative virulence of st. louis encephalitis virus cultured with brain tissue from innately susceptible and innately resistant mice. | we find that st. louis encephalitis virus cultured in 10 per cent serum-tyrode solution plus brain tissue from 1-day-old innately susceptible mice attains a higher titre than when cultured in a similar solution plus brain tissue from 1-day-old closely related, yet innately resistant mice. this difference in titre persists regardless of whether the serum comes from innately susceptible or resistant mice. the relatively high titre of virus in the susceptible media is not affected by the addition o ... | 1941 | 19871149 |
| influence of age on susceptibility of mice to st. louis encephalitis virus and on the distribution of lesions. | 1. young mice are more susceptible than older mice to the virus of st. louis encephalitis inoculated intraperitoneally, but with virus inoculated intracerebrally or intranasally, there is no significant age difference in susceptibility. the greatest change in the resistance to the virus inoculated intraperitoneally occurs between the 2nd and 3rd weeks of life. 2. the distribution of the lesions of st. louis encephalitis in the c.n.s. of young and of old animals following intraperitoneal inoculat ... | 1942 | 19871179 |
| laboratory transmission of st. louis encephalitis virus by three genera of mosquitoes. | 1. st. louis virus has been successfully transmitted in the laboratory by the following 9 species of mosquitoes from 3 genera: culex tarsalis, culex pipiens, culex coronator, aedes lateralis, aedes taeniorhynchus, aedes vexans, aedes nigromaculis, theobaldia incidens, and theobaldia inornata. 2. though transmission has not been demonstrated, survival of the virus for more than a few days was shown to occur in culex quinquefasciatus, culex stigmatosoma, psorophora ciliata, and anopheles maculipen ... | 1943 | 19871325 |
| neutralizing and complement-fixing antibody production and resistance following vaccination in experimental encephalitis infections. | in mice vaccinated subcutaneously with different doses of virulent w.e.e. virus or with formolized vaccine, neutralizing and complement-fixing antibodies paralleled resistance to some extent yet appeared in groups in which resistance remained undetectable, persisted at a similar maximum level in spite of different titers of resistance, and after resistance had become negligible. in mice vaccinated subcutaneously with different doses of virulent st. louis encephalitis virus or with formolized vac ... | 1943 | 19871341 |
| st. louis encephalitis virus in the blood of experimentally inoculated fowls and mammals. | 1. of three species of mammals tested by peripheral inoculation (guinea pig, cat, and horse) none showed viremia under conditions which suggested that any of these species would serve as a frequent source of mosquito infection. 2. of the birds tested (chicken, duck, and dove) all developed viremia and might readily serve as natural sources of mosquito infection. chickens were shown to be very highly susceptible to infection by minute amounts of virus inoculated subcutaneously. 3. virus may appea ... | 1946 | 19871523 |
| influence of anesthesia on experimental neurotropic virus infections : i. in vivo studies with the viruses of western and eastern equine encephalomyelitis, st. louis encephalitis, poliomyelitis (lansing), and rabies. | anesthesia with diethyl ether significantly alters the course and outcome of experimental infections with the equine encephalomyelitis virus (eastern or western type) or with the st. louis encephalitis virus. no comparable effect is observed in experimental infections produced with rabies or poliomyelitis (lansing) viruses. the neurotropic virus infections altered by ether anesthesia are those caused by viruses which are destroyed in vitro by this anesthetic, and those infections not affected by ... | 1946 | 19871570 |
| multiplication and spread of the virus of st. louis encephalitis in mice with special emphasis on its fate in the alimentary tract. | 1. beginning at 24 hours after intravenous injection of about 10 million intracerebral ld(50) of virus there was evidence of simultaneous, progressive multiplication in the brain and intestinal tract. 2. when the virus was introduced directly into the brain or the nasal cavities and mouth, none was found in the intestinal tract until there was general centrifugal spread from the central nervous system during the last stages of the infection at 96 or 120 hours after inoculation when the virus in ... | 1947 | 19871641 |
| seroprevalence of west nile virus infection in solid organ transplant recipients. | of people infected with mosquito-borne west nile virus (wnv), <1% develop neuroinvasive disease (nid). population studies suggest that people older than 65 years may be at higher risk for neurologic symptoms. it has been suggested that solid organ transplant (sot) recipients are also at higher risk for wnv nid, but definitive serologic and epidemiologic data are lacking. | 2010 | 19874565 |
| removal of species constraints in antibody detection. | serum antibodies from myriad species, particularly birds, can provide key information regarding the transmission and the expansion of the territory of emerging pathogens. expedient antibody analysis is constrained by a lack of species-specific reagents, a deficiency potentially highlighted by the recent swine-origin influenza a virus (h1n1) outbreak. available methodologies present difficulties that discourage thorough serologic monitoring of potential disease vectors or hosts. rapid high-throug ... | 2010 | 19923570 |
| experimental passage of st. louis encephalitis virus in vivo in mosquitoes and chickens reveals evolutionarily significant virus characteristics. | st. louis encephalitis virus (slev; flaviviridae, flavivirus) was the major cause of epidemic flaviviral encephalitis in the u.s. prior to the introduction of west nile virus (wnv) in 1999. however, outbreaks of slev have been significantly more limited then wnv in terms of levels of activity and geographic dispersal. one possible explanation for these variable levels of activity is that differences in the potential for each virus to adapt to its host cycle exist. the need for arboviruses to rep ... | 2009 | 19924238 |
| severe winter freezes enhance st. louis encephalitis virus amplification and epidemic transmission in peninsular florida. | mosquito-borne arboviral epidemics tend to strike without warning. the driving force for these epidemics is a combination of biotic (vector, amplification host, and virus) and abiotic (meteorological conditions, especially rainfall and temperature) factors. abiotic factors that facilitate the synchronization and interaction of vector and amplification host populations favor epidemic amplification and transmission. in florida, epidemics of st. louis encephalitis (sle) virus (family flaviviridae, ... | 2009 | 19960704 |
| multiple recombinants in two dengue virus, serotype-2 isolates from patients from oaxaca, mexico. | dengue (den) is a serious cause of mortality and morbidity in the world including mexico, where the infection is endemic. one of the states with the highest rate of dengue cases is oaxaca. the cause of den is a positive-sense rna virus, the dengue virus (denv) that evolves rapidly increasing its variability due to the absence of a repair mechanism that leads to approximately one mutational event per genome replication; which results in enhancement of viral adaptation, including the escape from h ... | 2009 | 20003526 |
| high throughput quantitative colorimetric microneutralization assay for the confirmation and differentiation of west nile virus and st. louis encephalitis virus. | an automated colorimetric micro-neutralization assay (cmnt) was developed for confirmation and differentiation of west nile virus (wnv)-positive human sera as a higher throughput alternative to the standard six-well plaque-reduction neutralization test (prnt). cmnt was performed in high-capacity 96-well micro-titer plates and required 4-6 days to complete. inhibition of infection was determined by reduced neutral red-dye retention and conveniently recorded by a colorimetric plate reader. human s ... | 2010 | 20207881 |
| ph stability of st. louis encephalitis virus. | | 1946 | 20277740 |
| a simple method for determining arbovirus transmission in mosquitoes. | we present a simplified method for the collection of mosquito saliva to determine culex pipiens quinquefasciatus transmission of west nile virus that can be used for experiments requiring large sample sizes. | 2010 | 20402359 |
| emergent infectious uveitis. | infectious causes should always be considered in all patients with uveitis and it should be ruled out first. the differential diagnosis includes multiple well-known diseases including herpes, syphilis, toxoplasmosis, tuberculosis, bartonellosis, lyme disease, and others. however, clinicians should be aware of emerging infectious agents as potential causes of systemic illness and also intraocular inflammation. air travel, immigration, and globalization of business have overturned traditional patt ... | 2009 | 20404989 |
| vertical transmission of st. louis encephalitis virus in culex quinquefasciatus (diptera: culicidae) in córdoba, argentina. | arbovirus vector transmission is interrupted when vector abundance decreases or disappears in temperate regions during the winter season. although the primary overwintering mechanism for many arboviruses in nature remains unknown, vertical transmission is one potential mechanism. vertical transmission functions as an overwintering mechanism for st. louis encephalitis virus (slev) in temperate areas of argentina, where slev is endemic. the aim of this project was to detect vertical transmission o ... | 2010 | 20426683 |
| bioinformatics in new generation flavivirus vaccines. | flavivirus infections are the most prevalent arthropod-borne infections world wide, often causing severe disease especially among children, the elderly, and the immunocompromised. in the absence of effective antiviral treatment, prevention through vaccination would greatly reduce morbidity and mortality associated with flavivirus infections. despite the success of the empirically developed vaccines against yellow fever virus, japanese encephalitis virus and tick-borne encephalitis virus, there i ... | 2010 | 20467477 |
| test of recrudescence hypothesis for overwintering of west nile virus in gray catbirds. | west nile virus is a pathogen of concern for both human and wildlife health. although many aspects of the ecology of west nile virus are well understood, the mechanisms by which this and similar mosquito-borne viruses overwinter and become reinitiated each spring in temperate regions is not known. a thorough understanding of this mechanism is crucial to risk assessment and development of control strategies. one of the hypotheses to explain the mechanism by which this virus persists from year to ... | 2010 | 20496593 |
| household-based sero-epidemiologic survey after a yellow fever epidemic, sudan, 2005. | from september through early december 2005, an outbreak of yellow fever (yf) occurred in south kordofan, sudan, resulting in a mass yf vaccination campaign. in late december 2005, we conducted a serosurvey to assess yf vaccine coverage and to better define the epidemiology of the outbreak in an index village. of 552 persons enrolled, 95% reported recent yf vaccination, and 25% reported febrile illness during the outbreak period: 13% reported yf-like illness, 4% reported severe yf-like illness, a ... | 2010 | 20519615 |
| sequential immunization with heterologous chimeric flaviviruses induces broad-spectrum cross-reactive cd8+ t cell responses. | flavivirus vaccines based on chimerivax technology contain the nonstructural genes of the yellow fever vaccine and the premembrane and envelope genes of heterologous flaviviruses, such as japanese encephalitis and west nile viruses. these chimeric vaccines induce both humoral and cell-mediated immunity. mice were vaccinated with yellow fever, chimeric japanese encephalitis virus (yf/je), or chimeric west nile virus (yf/wn) vaccines, followed by a secondary homologous or heterologous vaccination; ... | 2010 | 20536361 |
| molecular epidemiology of saint louis encephalitis virus in the brazilian amazon: genetic divergence and dispersal. | saint louis encephalitis virus (slev), a member of the genus flavivirus (family flaviviridae), is an encephalitogenic arbovirus broadly distributed in the americas. phylogenetic analysis based on the full-length e gene sequences obtained for 30 brazilian slev strains was performed using different methods including bayesian and relaxed molecular clock approaches. a new genetic lineage was suggested, hereafter named genotype viii, which co-circulates with the previously described genotype v in the ... | 2010 | 20592112 |
| environmental and biological factors influencing culex pipiens quinquefasciatus (diptera: culicidae) vector competence for west nile virus. | interactions between environmental and biological factors affect the vector competence of culex pipiens quinquefasciatus for west nile virus. three age cohorts from two cx. p. quinquefasciatus colonies were fed blood containing a low- or high-virus dose, and each group was held at two different extrinsic incubation temperatures (eit) for 13 days. the colonies differed in the way that they responded to the effects of the environment on vector competence. the effects of mosquito age on aspects of ... | 2010 | 20595491 |
| detection of saint louis encephalitis virus in dengue-suspected cases during a dengue 3 outbreak. | arboviruses are frequently associated with outbreaks in humans and represent a serious public health problem. among the brazilian arboviruses, mayaro virus, dengue virus (denv), yellow fever virus, rocio virus, saint louis encephalitis virus (slev), and oropouche virus are responsible for most of human cases. all these arboviruses usually produce undistinguishable acute febrile illness, especially in the acute phase of infection. in this study we investigated the presence of arboviruses in sera ... | 2011 | 20645866 |
| serosurveillance for japanese encephalitis and west nile viruses in resident birds in hawai'i. | japanese encephalitis virus (jev) and west nile virus (wnv) are emerging zoonotic arboviruses that have recently undergone intercontinental expansion. both jev and wnv are naturally transmitted between mosquito vectors and vertebrate reservoir hosts, including birds. a potential route of jev introduction from asia to western north america is via the hawaiian archipelago, while the spread of wnv from mainland north america to hawai'i is also considered an impending threat. we surveyed resident, n ... | 2010 | 20688669 |
| migratory birds and the dispersal of arboviruses in california. | each spring large numbers of neotropical migrants traversing the pacific flyway pass through the coachella valley enroute to northern destinations, providing an opportunity to test the hypothesis that mosquito-borne encephalitis viruses are introduced annually into california by migratory birds. a total of 5,632 sera were collected from 43 species of migrants during spring (april-june), of which 34 (0.61%) comprised of 14 species tested positive by enzyme immunoassay; only 10 were confirmed by p ... | 2010 | 20889869 |
| sequencing of culex quinquefasciatus establishes a platform for mosquito comparative genomics. | culex quinquefasciatus (the southern house mosquito) is an important mosquito vector of viruses such as west nile virus and st. louis encephalitis virus, as well as of nematodes that cause lymphatic filariasis. c. quinquefasciatus is one species within the culex pipiens species complex and can be found throughout tropical and temperate climates of the world. the ability of c. quinquefasciatus to take blood meals from birds, livestock, and humans contributes to its ability to vector pathogens bet ... | 2010 | 20929810 |
| development and evaluation of a formalin-inactivated west nile virus vaccine (wn-vax) for a human vaccine candidate. | a formalin-inactivated west nile virus (wnv) vaccine (wn-vax) derived from the wnv-ny99 strain was tested for its safety, efficacy, dilution limit for complete protection, and cross-neutralization. safety tests performed with experimental animals, bacteria, or cultured cell lines showed no evidence of short- or long-term adverse effects. wn-vax also protected 100% of 4-week-old mice against a lethal challenge from the wnv-ny99 strain after two doses of intraperitoneal inoculation-even when the v ... | 2010 | 20933564 |
| serologic evidence of the recent circulation of saint louis encephalitis virus and high prevalence of equine encephalitis viruses in horses in the nhecolândia sub-region in south pantanal, central-west brazil. | as in humans, sub-clinical infection by arboviruses in domestic animals is common; however, its detection only occurs during epizootics and the silent circulation of some arboviruses may remain undetected. the objective of the present paper was to assess the current circulation of arboviruses in the nhecolândia sub-region of south pantanal, brazil. sera from a total of 135 horses, of which 75 were immunized with bivalent vaccine composed of inactive eastern equine encephalitis virus (eeev) and w ... | 2010 | 20945001 |
| st. louis encephalitis virus in the blood of experimentally inoculated fowls and mammals. | | 1946 | 21016310 |
| isolation of st. louis encephalitis virus from the peripheral blood of a human subject. | | 1946 | 21023178 |
| isolation of st. louis encephalitis virus from a fatal human case in california. | | 1946 | 21024144 |
| vector competence of florida mosquitoes for chikungunya virus. | | 2010 | 21175954 |
| temporal and spatial alterations in mutant swarm size of st. louis encephalitis virus in mosquito hosts. | st. louis encephalitis virus (slev; flaviviridae; flavivirus) is a member of the japanese encephalitis serocomplex and a close relative of west nile virus (wnv). although slev remains endemic to the us, both levels of activity and geographical dispersal are relatively constrained when compared to the widespread distribution of wnv. in recent years, wnv appears to have displaced slev in california, yet both viruses currently coexist in texas and several other states. it has become clear that vira ... | 2011 | 21215334 |
| application of satellite precipitation data to analyse and model arbovirus activity in the tropics. | murray valley encephalitis virus (mvev) is a mosquito-borne flavivirus (flaviviridae: flavivirus) which is closely related to japanese encephalitis virus, west nile virus and st. louis encephalitis virus. mvev is enzootic in northern australia and papua new guinea and epizootic in other parts of australia. activity of mvev in western australia (wa) is monitored by detection of seroconversions in flocks of sentinel chickens at selected sample sites throughout wa. rainfall is a major environmental ... | 2011 | 21255449 |
| evaluation of widely used diagnostic tests to detect west nile virus infections in horses previously infected with st. louis encephalitis virus or dengue virus type 2. | primary west nile virus (wnv) infections can be diagnosed using a number of tests that detect infectious particles, nucleic acid, and specific igm and/or igg antibodies. however, serological identification of the infecting agent in secondary or subsequent flavivirus infections is problematic due to the extensive cross-reactivity of flavivirus antibodies. this is particularly difficult in the tropical americas where multiple flaviviruses cocirculate. a study of sequential flavivirus infection in ... | 2011 | 21346058 |
| real-time monitoring of flavivirus induced cytopathogenesis using cell electric impedance technology. | a real-time cell analysis (rtca) system based on cell-substrate electric impedance technology was used to monitor cytopathic effects (cpe) in vero cell cultures infected with west nile virus (wnv) and st. louis encephalitis virus (slev) at infectious doses ranging from 10(1) to 10(6) plaque forming units (pfu) of virus. a kinetic parameter characterizing virus-induced cpe, cit(50) or the time to 50% decrease in cell impedance, was inversely proportional to virus infectious dose. in wnv-infected ... | 2011 | 21349291 |
| identification of a conserved jev serocomplex b-cell epitope by screening a phage-display peptide library with a mab generated against west nile virus capsid protein. | the west nile virus (wnv) capsid (c) protein is one of the three viral structural proteins, encapsidates the viral rna to form the nucleocapsid, and is necessary for nuclear and nucleolar localization. the antigenic sites on c protein that are targeted by humoral immune responses have not been studied thoroughly, and well-defined b-cell epitopes on the wnv c protein have not been reported. | 2011 | 21375771 |
| evaluation of two molecular methods for the detection of yellow fever virus genome. | yellow fever virus (yfv), a member of the family flaviviridae, genus flavivirus is endemic to tropical areas of africa and south america and is among the arboviruses that pose a threat to public health. recent outbreaks in brazil, bolivia, and paraguay and the observation that vectors capable of transmitting yfv are presenting in urban areas underscore the urgency of improving surveillance and diagnostic methods. two novel methods (rt-hemi-nested-pcr and sybr(®) green qrt-pcr) for efficient dete ... | 2011 | 21419803 |
| silencing early viral replication in macrophages and dendritic cells effectively suppresses flavivirus encephalitis. | west nile (wn) and st. louis encephalitis (sle) viruses can cause fatal neurological infection and currently there is neither a specific treatment nor an approved vaccine for these infections. in our earlier studies, we have reported that sirnas can be developed as broad-spectrum antivirals for the treatment of infection caused by related viruses and that a small peptide called rvg-9r can deliver sirna to neuronal cells as well as macrophages. to increase the repertoire of broad-spectrum antifla ... | 2011 | 21423625 |
| surveillance for west nile virus and vaccination of free-ranging island scrub-jays (aphelocoma insularis) on santa cruz island, california. | abstract transmission of west nile virus (wnv) on mainland california poses an ongoing threat to the island scrub-jay (issj, aphelocoma insularis), a species that occurs only on santa cruz island, california, and whose total population numbers <5000. our report describes the surveillance and management efforts conducted since 2006 that are designed to understand and mitigate for the consequences of wnv introduction into the issj population. we suspect that wnv would most likely be introduced to ... | 2011 | 21438695 |
| seroprevalence of west nile virus in feral horses on sheldon national wildlife refuge, nevada, united states. | we screened 1,397 feral horses (equus caballus) on sheldon national wildlife refuge, nevada, united states, for igm and igg against flavivirus during 2004-2006, 2008, and 2009. positive serum samples were tested for neutralizing antibodies to west nile virus (wnv) and st. louis encephalitis virus (slev). one animal was positive for antibody against wnv in 2004, but all others tested in 2004-2006 were negative. in 2008 and 2009, we found evidence of increasing seropositive horses with age, wherea ... | 2011 | 21460023 |
| the f1 motif of dengue virus polymerase ns5 is involved in promoter-dependent rna synthesis. | the mechanism by which viral rna-dependent rna polymerases (rdrp) specifically amplify viral genomes is still unclear. in the case of flaviviruses, a model has been proposed that involves the recognition of an rna element present at the viral 5' untranslated region, stem-loop a (sla), that serves as a promoter for ns5 polymerase binding and activity. here, we investigated requirements for specific promoter-dependent rna synthesis of the dengue virus ns5 protein. using mutated purified ns5 recomb ... | 2011 | 21471248 |
| pathogenesis of japanese encephalitis virus infection in a golden hamster model and evaluation of flavivirus cross-protective immunity. | abstract. japanese encephalitis virus (jev) is a mosquito-borne flavivirus endemic to southeast asia and surrounding pacific islands, and it has most recently emerged in northern australia. jev is closely related to west nile virus (wnv) and st. louis encephalitis virus (slev), both endemic to the united states. in the event that jev is introduced into the americas, it will be important to determine whether immunity to wnv or slev might afford protection from infection and development of viremia ... | 2011 | 21540381 |
| comparison of argentinean saint louis encephalitis virus non-epidemic and epidemic strain infections in an avian model. | st. louis encephalitis virus (slev, flavivirus, flaviviridae) is an emerging mosquito-borne pathogen in south america, with human slev encephalitis cases reported in argentina and brazil. genotype iii strains of slev were isolated from culex quinquefasciatus mosquitoes in cordoba, argentina in 2005, during the largest slev outbreak ever reported in south america. the present study tested the hypothesis that the recent, epidemic slev strain exhibits greater virulence in birds as compared with a n ... | 2011 | 21629729 |
| weather and land cover influences on mosquito populations in sioux falls, south dakota. | this study compared the spatial and temporal patterns of culex tarsalis coquillett and aedes vexans meigen populations and examined their relationships with land cover types and climatic variability in sioux falls, sd. between 24 and 30 cdc co2-baited light traps were set annually in sioux falls from may to september 2005-2008. land cover data were acquired from the 2001 national land cover dataset and the percentages of selected land cover types were calculated within a 600-m buffer zone around ... | 2011 | 21661329 |
| west nile virus disease and other arboviral diseases --- united states, 2010. | arthropod-borne viruses (arboviruses) are transmitted to humans primarily through the bites of infected mosquitoes and ticks. since west nile virus (wnv) was first detected in the western hemisphere in 1999, it has become the leading cause of neuroinvasive arboviral disease in the united states. however, several other arboviruses continue to cause sporadic cases and seasonal outbreaks of neuroinvasive disease (i.e., meningitis, encephalitis, or acute flaccid paralysis). this report summarizes su ... | 2011 | 21814163 |
| an experimental model of meningoencephalomyelitis by rocio flavivirus in balb/c mice: inflammatory response, cytokine production, and histopathology. | abstract. rocio virus (rocv) is a flavivirus, probably transmitted by culex mosquitoes and maintained in nature as a zoonosis of wild birds. rocio virus caused a human epidemic of severe encephalitis that lasted from 1973 to 1980 in the ribeira valley, in the southeastern coast of brazil. after this outbreak, serologic evidence of rocv circulation has been reported and public health authorities are concerned about a return of rocv outbreaks in brazil. we show here a study on the pathogenesis and ... | 2011 | 21813860 |
| west nile virus aseptic meningitis and stuttering in woman. | to the editor: west nile virus (wnv), a mosquito-borne flavivirus, is closely related to st. louis encephalitis virus and japanese encephalitis virus (jev). most cases of wnv have been mild, but neuroinvasive disease has been observed, especially among older persons and immunocompromised persons (1,2). the most common neurologic manifestations of wnv are aseptic meningitis, meningoencephalitis, and encephalitis with or without acute flaccid paralysis (3). other less common neurologic manifestati ... | 2011 | 21801656 |
| [saint louis encephalitis virus in buenos aires city during the outbreak of dengue in 2009.] | we report the case of a male, 80-year-old resident in the city of buenos aires, with a diagnosis of st. louis encephalitis (sle) during a countrywide dengue outbreak, from january to may 2009. the patient had a chronic lymphocytic leukemia treated with chlorambucil, prostate cancer (hormone therapy and radiotherapy) and images consistent with bone metastases. cerebrospinal fluid examination showed pleocytosis with a predominance of mononuclear cells and high protein concentration. bacteria, fung ... | 2011 | 21745774 |
| [outbreack of st. luis encephalitis in the metropolitan buenos aires area.] | we describe the epidemiological and clinical findings of 13 patients with diagnosis of infection by st. louis encephalitis virus, transmitted between january and march 2010 in buenos aires metropolitan area (amba). thirteen patients, average age 38 years, had an acute onset with hyperthermia and headache. between days two and ten of the onset of symptoms, 7/13 patients had signs and symptoms of neurological involvement. this was characterized by meningitis without encephalic sings in 1/7 and in ... | 2011 | 21745768 |
| identification of two linear b-cell epitopes from west nile virus ns1 by screening a phage-displayed random peptide library. | abstract: | 2011 | 21729328 |
| immunoglobulin g subclasses in antibody responses to st. louis encephalitis virus infections. | the aim of this study was to recognize the specific antiviral response patterns of igg1, igg2, igg3 and igg4 subclasses, elicited during st. louis encephalitis virus (slev) infection in humans. eighty-five samples of human sera from 44 patients with slev infection were obtained between days 1 and 365 or later, after onset of the disease. these samples were processed by immunofluorescence assay for detection of igg1-, igg2-, igg3- and igg4-specific antibodies. we demonstrate the presence of all i ... | 2011 | 21688106 |
| neutralising antibodies for west nile virus in horses from brazilian pantanal. | despite evidence of west nile virus (wnv) activity in colombia, venezuela and argentina, this virus has not been reported in most south american countries. in february 2009, we commenced an investigation for wnv in mosquitoes, horses and caimans from the pantanal, central-west brazil. the sera of 168 horses and 30 caimans were initially tested using a flaviviruses-specific epitope-blocking enzyme-linked immunosorbent assay (blocking elisa) for the detection of flavivirus-reactive antibodies. the ... | 2011 | 21739036 |
| the ns1 glycoprotein can generate dramatic antibody-enhanced dengue viral replication in normal out-bred mice resulting in lethal multi-organ disease. | antibody-enhanced replication (aer) of dengue type-2 virus (denv-2) strains and production of antibody-enhanced disease (aed) was tested in out-bred mice. polyclonal antibodies (pabs) generated against the nonstructural-1 (ns1) glycoprotein candidate vaccine of the new guinea-c (ng-c) or nsx strains reacted strongly and weakly with these antigens, respectively. these pabs contained the igg2a subclass, which cross-reacted with the virion-associated envelope (e) glycoprotein of the denv-2 nsx stra ... | 2011 | 21731643 |
| winter biology of wetland mosquitoes at a focus of eastern equine encephalomyelitis virus transmission in alabama, usa. | at temperate latitudes, vectors and pathogens must possess biological mechanisms for coping with cold temperatures and surviving from one transmission season to the next. mosquitoes that overwinter in the adult stage have been proposed as winter maintenance hosts for certain arboviruses. in the cases of west nile virus (family flaviviridae, genus flavivirus) and st. louis encephalitis virus (family flaviviridae, genus flavivirus), discovery of infected overwintering females lends support to this ... | 2011 | 21936314 |
| new sensitive competitive elisa using monoclonal antibody against non-structural protein 1 of west nile virus ny99. | anti-west nile virus (wnv) monoclonal antibody, shw-7a11 was newly developed for competitive elisa (c-elisa). shw-7a11 reacted with non-structural protein 1 in western blot analysis. shw-7a11 was relatively specific for the wnv strain ny99 and recognized kunjin and eg101 strains in indirect elisa. two c-elisas were developed for 10 and 100 times diluted sera and named c-elisa10 and c-elisa100, respectively. both c-elisas detected antibodies against wnv ny99 and kunjin strains. little cross-react ... | 2011 | 22190400 |
| Uncoupling cis-Acting RNA Elements from Coding Sequences Revealed a Requirement of the N-Terminal Region of Dengue Virus Capsid Protein in Virus Particle Formation. | Little is known about the mechanism of flavivirus genome encapsidation. Here, functional elements of the dengue virus (DENV) capsid (C) protein were investigated. Study of the N-terminal region of DENV C has been limited by the presence of overlapping cis-acting RNA elements within the protein-coding region. To dissociate these two functions, we used a recombinant DENV RNA with a duplication of essential RNA structures outside the C coding sequence. By the use of this system, the highly conserve ... | 2012 | 22072762 |
| Structural gene (prME) chimeras of St Louis encephalitis virus and West Nile virus exhibit altered in vitro cytopathic and growth phenotypes. | Despite utilizing the same avian hosts and mosquito vectors, St Louis encephalitis virus (SLEV) and West Nile virus (WNV) display dissimilar vector-infectivity and vertebrate-pathogenic phenotypes. SLEV exhibits a low oral infection threshold for Culex mosquito vectors and is avirulent in avian hosts, producing low-magnitude viraemias. In contrast, WNV is less orally infective to mosquitoes and elicits high-magnitude viraemias in a wide range of avian species. In order to identify the genetic de ... | 2012 | 21940408 |
| evaluation of the human host range of bovine and porcine viruses that may contaminate bovine serum and porcine trypsin used in the manufacture of biological products. | current u.s. requirements for testing cell substrates used in production of human biological products for contamination with bovine and porcine viruses are u.s. department of agriculture (usda) 9cfr tests for bovine serum or porcine trypsin. 9cfr requires testing of bovine serum for seven specific viruses in six families (immunofluorescence) and at least 2 additional families non-specifically (cytopathicity and hemadsorption). 9cfr testing of porcine trypsin is for porcine parvovirus. recent con ... | 2011 | 22000165 |
| functional rna elements in the dengue virus genome. | dengue virus (denv) genome amplification is a process that involves the viral rna, cellular and viral proteins, and a complex architecture of cellular membranes. the viral rna is not a passive template during this process; it plays an active role providing rna signals that act as promoters, enhancers and/or silencers of the replication process. rna elements that modulate rna replication were found at the 5' and 3' utrs and within the viral coding sequence. the promoter for denv rna synthesis is ... | 2011 | 21994804 |
| mapping environmental susceptibility to saint louis encephalitis virus, based on a decision tree model of remotelysensed data. | in response to the first human outbreak (january may 2005) of saint louis encephalitis (sle) virus in córdoba province, argentina, we developed an environmental sle virus risk map for the capital, i.e. córdoba city. the aim was to provide a map capable of detecting macro-environmental factors associated with the spatial distribution of sle cases, based on remotely sensed data and a geographical information system. vegetation, soil brightness, humidity status, distances to water-bodies and areas ... | 2011 | 22109866 |
| novel flaviviruses detected in different species of mosquitoes in spain. | abstract we report the characterization of three novel flaviviruses isolated in spain. marisma mosquito virus, a novel mosquito borne virus, was isolated from ochlerotatus caspius mosquitoes; spanish ochlerotatus flavivirus and spanish culex flavivirus, two novel insect flaviviruses, were isolated from oc. caspius and culex pipiens, respectively. during this investigation, we designed a sensitive rt-nested polymerase chain reaction method that amplifies a 1019bp fragment of the flavivirus ns5 ... | 2011 | 22022811 |
| west nile virus: north american experience. | west nile virus, a mosquito-vectored flavivirus of the japanese encephalitis serogroup, was first detected in north america following an epizootic in the new york city area in 1999. in the intervening 11 years since the arrival of the virus in north america, it has crossed the contiguous usa, entered the canadian provinces bordering the usa, and has been reported in the caribbean islands, mexico, central america and, more recently, south america. west nile virus has been reported in over 300 spe ... | 2011 | 21910847 |
| West Nile virus: immunity and pathogenesis. | West Nile virus (WNV) is a neurotropic, arthropod-borne flavivirus that is maintained in an enzootic cycle between mosquitoes and birds, but can also infect and cause disease in horses and humans. WNV is endemic in parts of Africa, Europe, the Middle East, and Asia, and since 1999 has spread to North America, Mexico, South America, and the Caribbean. WNV infects the central nervous system (CNS) and can cause severe disease in a small minority of infected humans, mostly immunocompromised or the e ... | 2011 | 21994755 |
| mayaro fever in the city of manaus, brazil, 2007-2008. | abstract mayaro alphavirus is an arbovirus that causes outbreaks of acute febrile illness in the amazon region of south america. we show here the cases of mayaro fever that occurred in 2007-2008, in manaus, a large city and capital of the amazonas state, in western brazilian amazon. igm antibodies to mayaro virus (mayv) were detected by an enzyme immunoassay using infected cell cultures as antigen in the sera of 33 patients from both genera and 6-65 years old. mayv genome was also detected by ... | 2011 | 21923266 |
| seroconversion for west nile and st. louis encephalitis viruses among sentinel horses in colombia. | we prospectively sampled flavivirus-naïve horses in northern colombia to detect west nile virus (wnv) and st. louis encephalitis virus (slev) seroconversion events, which would indicate the current circulation of these viruses. overall, 331 (34.1%) of the 971 horses screened were positive for past infection with flaviviruses upon initial sampling in july 2006. during the 12-month study from july 2006-june 2007, 33 wnv seroconversions and 14 slev seroconversions were detected, most of which occur ... | 2011 | 22241119 |
| [expression, purification and identification of st. louis encephalitis virus-like particles in eukaryotic cells]. | to express st. louis encephalitis virus-like particles in mammalian cells, it will provide a prerequisite for further immunological diagnostic studies. | 2011 | 22734220 |
| two cases of saint louis encephalitis in hiv-1 infected patients in buenos aires. | saint louis encephalitis virus (sle) is a mosquito borne disease. only a small proportion of cases progress to severe clinical forms. there have been few reports on hiv-infected patients and the relationship between immunodeficiency and the course of the disease remains unclear. herein we describe two cases of sle in hiv-1-infected patients in buenos aires city. | 2011 | 22218524 |
| the culex pipiens complex in the mississippi river basin: identification, distribution, and bloodmeal hosts. | members of the culex pipiens complex are the primary vectors of st. louis encephalitis virus and west nile virus in the mississippi river basin (mrb). the cx. pipiens complex in the mrb is composed of 4 taxa: cx. p. pipiens form pipiens, cx. p. quinquefasciatus, hybrids between cx. p. pipiens f. pipiens and cx. p. quinquefasciatus, and cx. p. pipiens form molestus. three studies on bloodmeal hosts with large sample sizes have been conducted on members of the cx. pipiens complex in the mrb includ ... | 2012 | 23401948 |
| effects of virus dose and extrinsic incubation temperature on vector competence of culex nigripalpus (diptera: culicidae) for st. louis encephalitis virus. | culex nigripalpus theobald is a primary vector of st. louis encephalitis virus in the southeastern united states. cx. nigripalpus females were fed blood containing a low (4.0 +/- 0.01 log10 plaque-forming unit equivalents (pfueq) /ml) or high (4.7 +/- 0.1 log10 pfueq/ml) st. louis encephalitis virus dose and maintained at extrinsic incubation temperatures (eit) of 25 or 28 degrees c for 12 d. vector competence was measured via quantitative real-time reverse transcriptase polymerase chain reactio ... | 2012 | 23270182 |
| a new competitive elisa detects west nile virus infection using monoclonal antibodies against the precursor-membrane protein of west nile virus. | precursor membrane protein (prm) is found in the envelope of immature west nile virus (wnv) particles. anti-prm antibodies are found in flavivirus-infected animal sera, and they are known as relatively virus species specific antibodies. however, there are no known reports of wnv-specific epitope blocking or competitive enzyme-linked immunosorbent assay (c-elisa) that detect anti-prm antibodies. two anti-wnv-prm monoclonal antibodies (shw-29c2 and shw-31b2) were generated, and c-elisas were devel ... | 2012 | 23266257 |
| potential role of deer tick virus in powassan encephalitis cases in lyme disease-endemic areas of new york, u.s.a. | powassan virus, a member of the tick-borne encephalitis group of flaviviruses, encompasses 2 lineages with separate enzootic cycles. the prototype lineage of powassan virus (powv) is principally maintained between ixodes cookei ticks and the groundhog (marmota momax) or striped skunk (mephitis mephitis), whereas the deer tick virus (dtv) lineage is believed to be maintained between ixodes scapularis ticks and the white-footed mouse (peromyscus leucopus). we report 14 cases of powassan encephalit ... | 2013 | 24274334 |
| commentary. | | 2014 | 25540529 |
| opsoclonus-myoclonus syndrome attributable to west nile encephalitis: a case report. | opsoclonus-myoclonus syndrome is a very rare neurological disorder associated with some viral infections and exceptionally with the west nile virus. | 2014 | 24968889 |
| 14(th) annual southern hospital medicine conference abstracts. | | 2014 | 24688348 |
| molecular detection of flaviviruses and alphaviruses in mosquitoes (diptera: culicidae) from coastal ecosystems in the colombian caribbean. | arboviruses belonging to the genera flavivirus and alphavirus were detected in mosquitoes in a rural area of san bernardo del viento (córdoba, colombia). a total of 22,180 mosquitoes were collected, sorted into 2,102 pools, and tested by generic/nested reverse transcription-polymerase chain reaction. venezuelan equine encephalitis virus, dengue virus, west nile virus, st. louis encephalitis virus, yellow fever virus, and culex flavivirus were detected and identified by sequencing. the detection ... | 2016 | 27706377 |
| surveillance for western equine encephalitis, st. louis encephalitis, and west nile viruses using reverse transcription loop-mediated isothermal amplification. | collection of mosquitoes and testing for vector-borne viruses is a key surveillance activity that directly influences the vector control efforts of public health agencies, including determining when and where to apply insecticides. vector control districts in california routinely monitor for three human pathogenic viruses including west nile virus (wnv), western equine encephalitis virus (weev), and st. louis encephalitis virus (slev). reverse transcription quantitative polymerase chain reaction ... | 2016 | 26807734 |
| field investigations of winter transmission of eastern equine encephalitis virus in florida. | studies investigating winter transmission of eastern equine encephalitis virus (eeev) were conducted in hillsborough county, florida. the virus was detected in culiseta melanura and anopheles quadrimaculatus in february 2012 and 2013, respectively. during the winter months, herons were the most important avian hosts for all mosquito species encountered. in collections carried out in the summer of 2011, blood meals taken from herons were still common, but less frequently encountered than in winte ... | 2014 | 25070997 |
| diagnosis of arboviruses using indirect sandwich igg elisa in horses from the brazilian amazon. | the amazon as a whole is the largest reservoir of arboviruses worldwide, while the brazilian amazon hosts the largest variety of arboviruses isolated to date. in this study, the results of an indirect sandwich igg elisa, standardized for 19 arbovirustypes circulating among horses in brazilian amazon, were compared to results of the hemagglutination inhibition test. a screening test assessed the conditional probability distribution and a pearson linear correlation test determined the correlation ... | 2014 | 25013410 |
| isolation of saint louis encephalitis virus from a horse with neurological disease in brazil. | st. louis encephalitis virus (slev) is a causative agent of encephalitis in humans in the western hemisphere. slev is a positive-sense rna virus that belongs to the flavivirus genus, which includes west nile encephalitis virus, japanese encephalitis virus, dengue virus and other medically important viruses. recently, we isolated a slev strain from the brain of a horse with neurological signs in the countryside of minas gerais, brazil. the slev isolation was confirmed by reverse-transcription rt- ... | 2013 | 24278489 |
| serological evidence of flaviviruses and alphaviruses in livestock and wildlife in trinidad. | seroprevalence rates of selected arboviruses in animal populations in trinidad were determined using serum samples collected between 2006 and 2009 from horses (n=506), cattle (n=163), sheep (n=198), goats (n=82), pigs (n=184), birds (n=140), rodents (n=116), and other vertebrates (n=23). the sera were screened for antibodies to west nile virus (wnv), st. louis encephalitis virus (slev), ilheus virus (ilhv), bussuquara virus (bsqv), venezuelan equine encephalitis virus (veev), eastern equine ence ... | 2012 | 22989182 |
| fighting arbovirus transmission: natural and engineered control of vector competence in aedes mosquitoes. | control of aedine mosquito vectors, either by mosquito population reduction or replacement with refractory mosquitoes, may play an essential role in the fight against arboviral diseases. in this review, we will focus on the development and application of biological approaches, both natural or engineered, to limit mosquito vector competence for arboviruses. the study of mosquito antiviral immunity has led to the identification of a number of host response mechanisms and proteins that are required ... | 2015 | 26463078 |
| structure of the st. louis encephalitis virus postfusion envelope trimer. | st. louis encephalitis virus (slev) is a mosquito-borne flavivirus responsible for several human encephalitis outbreaks over the last 80 years. mature flavivirus virions are coated with dimeric envelope (e) proteins that mediate attachment and fusion with host cells. e is a class ii fusion protein, the hallmark of which is a distinct dimer-to-trimer rearrangement that occurs upon endosomal acidification and insertion of hydrophobic fusion peptides into the endosomal membrane. herein, we report t ... | 2012 | 23115296 |
| flavivirus rna synthesis in vitro. | establishment of in vitro systems to study mechanisms of rna synthesis for positive strand rna viruses have been very useful in the past and have shed light on the composition of protein and rna components, optimum conditions, the nature of the products formed, cis-acting rna elements and trans-acting protein factors required for efficient synthesis. in this review, we summarize our current understanding regarding the requirements for flavivirus rna synthesis in vitro. we describe details of rea ... | 2015 | 26272247 |
| differential innate immune response programs in neuronal subtypes determine susceptibility to infection in the brain by positive-stranded rna viruses. | although susceptibility of neurons in the brain to microbial infection is a major determinant of clinical outcome, little is known about the molecular factors governing this vulnerability. here we show that two types of neurons from distinct brain regions showed differential permissivity to replication of several positive-stranded rna viruses. granule cell neurons of the cerebellum and cortical neurons from the cerebral cortex have unique innate immune programs that confer differential susceptib ... | 2013 | 23455712 |