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William K. Reisen - One of the best experts on this subject based on the ideXlab platform.
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WeSt.Nile and St. Louis Encephalitis viral genetic determinants of avian hoSt.competence
2018Co-Authors: Payal D. Maharaj, William K. Reisen, Stanley A. Langevin, Angela M. Bosco-lauth, Michael Anishchenko, Richard A. Bowen, Aaron C. BraultAbstract:WeSt.Nile virus (WNV) and St. Louis Encephalitis (SLEV) virus are enzootically maintained in North America in cycles involving the same mosquito vectors and similar avian hoSt.. However, these viruses exhibit dissimilar viremia and virulence phenotypes in birds: WNV is associated with high magnitude viremias that can result in mortality in certain species such as American crows (AMCRs, Corvus brachyrhynchos) whereas SLEV infection yields lower viremias that have not been associated with avian mortality. Cross-neutralization of these viruses in avian sera has been proposed to explain the reduced circulation of SLEV since the introduction of WNV in North America; however, in 2015, both viruses were the etiologic agents of concurrent human Encephalitis outbreaks in Arizona, indicating the need to re-evaluate hoSt.factors and cross-neutralization responses as factors potentially affecting viral co-circulation. Reciprocal chimeric WNV and SLEV viruses were conSt.ucted by interchanging the pre-membrane (prM)-envelope (E) genes, and viruses subsequently generated were utilized herein for the inoculation of three different avian species: house sparrows (HOSPs; Passer domeSt.cus), house finches (Haemorhous mexicanus) and AMCRs. Cross-protective immunity between parental and chimeric viruses were also assessed in HOSPs. Results indicated that the prM-E genes did not modulate avian replication or virulence differences between WNV and SLEV in any of the three avian species. However, WNV-prME proteins did dictate cross-protective immunity between these antigenically heterologous viruses. Our data provides further evidence of the important role that the WNV / SLEV viral non-St.uctural genetic elements play in viral replication, avian hoSt.competence and virulence.
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Serologic Diagnosis of WeSt.Nile and St. Louis Encephalitis Virus Infections in DomeSt.c Chickens
2016Co-Authors: Peter J. Patiris, William K. Reisen, Robert E Chiles, Leopoldo F. Oceguera, George W. Peck, Carl V. HansonAbstract:AbSt.act. Adult domeSt.c chickens were infected with WeSt.Nile virus (WNV) or St. Louis Encephalitis virus (SLEV) and challenged with homologous or heterologous virus at 21 or 56 days poSt.nfection (dpi). Sera were collected at selected time points after infection and assayed by enzyme immunoassay (EIA), plaque reduction neutralization teSt.(PRNT), and a WeSt.rn blot (WB) alternative to PRNT. EIA results were sensitive and accurate (few false positives) but not specific, requiring a confirmatory teSt.to determine virus infection hiSt.ry. PRNT results generally were specific until challenge, after which teSt.results were frequently equivocal and inadequate to determine firSt.or second infecting virus. WB results confirmed the serologic cross-reactivity between WNV and SLEV envelope protein. Non-St.uctural protein 1 and pre-membrane protein reactivities were highly specific for WNV during SLEV infection, but less specific for SLEV during WNV infection. WB and PRNT specificities were similar for both viruses from 6 to 14 dpi, and sensitivities to WNV were virtually identical
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Surveys for Antibodies AgainSt.Mosquitoborne Encephalitis Viruses in California Birds, 1996-2013.
Vector-borne and Zoonotic Diseases, 2016Co-Authors: William K. Reisen, Sarah S. WheelerAbstract:AbSt.act From 1996 through 2013, 54,546 individual birds comprising 152 species and 7 orders were banded, bled, and released at four St.dy areas within California, from which 28,388 additional serum samples were collected at one or more recapture encounters. Of these, 142, 99, and 1929 birds from 41 species were positive for neutralizing antibodies againSt.weSt.rn equine encephalomyelitis virus (WEEV), St. Louis Encephalitis virus (SLEV), or WeSt.Nile virus (WNV) at initial capture or recapture, respectively. Overall, 83% of the positive serum samples were collected from five species: House Finch, House Sparrow, Mourning Dove, California Quail, and WeSt.rn Scrub-Jay. Temporal data supported concurrent arbovirus surveillance and documented the disappearance of birds positive for WEEV in 2008 and SLEV in 2003 and the appearance of birds positive for WNV after its invasion in 2003. Results of these serosurveys agreed well with the hoSt.selection patterns of the Culex vectors as described from bloodmeal seque...
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Reemergence of St. Louis Encephalitis Virus, California, 2015
Centers for Disease Control and Prevention, 2016Co-Authors: Gregory S. White, William K. Reisen, Sandra García, Ying Fang, Kelly Symmes, Pu Sun, Cody Steiner, Kirk Smith, Lark L. CoffeyAbstract:St. Louis Encephalitis virus infection was detected in summer 2015 in southern California after an 11-year absence, concomitant with an Arizona outbreak. Sequence comparisons showed close identity of California and Arizona isolates with 2005 Argentine isolates, suggeSt.ng introduction from South America and underscoring the value of continued arbovirus surveillance
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multiplex qrt pcr for the detection of weSt.rn equine encephalomyelitis St.Louis Encephalitis and weSt.nile viral rna in mosquito pools diptera culicidae
Journal of Medical Entomology, 2015Co-Authors: Aaron C. Brault, Ying Fang, William K. ReisenAbstract:Following the introduction of WeSt.Nile virus into California during the summer of 2003, public health and vector control programs expanded surveillance efforts and were in need of diagnoSt.cs capable of rapid, sensitive, and specific detection of arbovirus infections of mosquitoes to inform decision support for intervention. Development of a multiplex TaqMan or real-time semiquantitative reverse transcription polymerase chain reaction (RT-PCR) assay in which three virus specific primer–probe sets were used in the same reaction is described herein for the detection of weSt.rn equine encephalomyelitis, St. Louis Encephalitis and WeSt.Nile viral RNA. Laboratory validation and field data from 10 transmission seasons are reported. The comparative sensitivity and specificity of this multiplex assay to singleplex RT-PCR as well as an antigen detection (rapid analyte measurement platform) and St.ndard plaque assays indicate this assay to be rapid and useful in providing mosquito infection data to eSt.mate outbreak risk.
Ying Fang - One of the best experts on this subject based on the ideXlab platform.
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Movement of St. Louis Encephalitis virus in the WeSt.rn United St.tes, 2014- 2018.
PLOS Neglected Tropical Diseases, 2020Co-Authors: Daniele M. Swetnam, Sandra García, Ying Fang, Christopher M Barker, Payal D. Maharaj, Jackson B. Stuart, Katherine Young, Kirk E. Smith, Marvin S. Godsey, Harry M. SavageAbstract:St. Louis Encephalitis virus (SLEV) is a flavivirus that circulates in an enzootic cycle between birds and mosquitoes and can also infect humans to cause febrile disease and sometimes Encephalitis. Although SLEV is endemic to the United St.tes, no activity was detected in California during the years 2004 through 2014, despite continuous surveillance in mosquitoes and sentinel chickens. In 2015, SLEV-positive mosquito pools were detected in Maricopa County, Arizona, concurrent with an outbreak of human SLEV disease. SLEV-positive mosquito pools were also detected in southeaSt.rn California and Nevada in summer 2015. From 2016 to 2018, SLEV was detected in mosquito pools throughout southern and central California, Oregon, Idaho, and Texas. To underSt.nd genetic relatedness and geographic dispersal of SLEV in the weSt.rn United St.tes since 2015, we sequenced four hiSt.rical genomes (3 from California and 1 from Louisiana) and 26 contemporary SLEV genomes from mosquito pools from locations across the weSt.rn US. Bayesian phylogeographic approaches were then applied to map the recent spread of SLEV. Three routes of SLEV dispersal in the weSt.rn United St.tes were identified: Arizona to southern California, Arizona to Central California, and Arizona to all locations eaSt.of the Sierra Nevada mountains. Given the topography of the WeSt.rn United St.tes, these routes may have been limited by mountain ranges that influence the movement of avian reservoirs and mosquito vectors, which probably represents the primary mechanism of SLEV dispersal. Our analysis detected repeated SLEV introductions from Arizona into southern California and limited evidence of year-to-year persiSt.nce of genomes of the same anceSt.y. By contraSt. genetic tracing suggeSt. that all SLEV activity since 2015 in central California is the result of a single persiSt.nt SLEV introduction. The identification of natural barriers that influence SLEV dispersal enhances our underSt.nding of arbovirus ecology in the weSt.rn United St.tes and may also support regional public health agencies in implementing more targeted vector mitigation efforts to protect their communities more effectively.
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Surveillance for WeSt.rn Equine Encephalitis, St. Louis Encephalitis, and WeSt.Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification.
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and teSt.ng 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 diSt.icts in California routinely monitor for three human pathogenic viruses including WeSt.Nile virus (WNV), WeSt.rn equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires coSt.y, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonSt.uctural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of
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surveillance for weSt.rn equine Encephalitis St.Louis Encephalitis and weSt.nile viruses using reverse transcription loop mediated isothermal amplification
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and teSt.ng 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 diSt.icts in California routinely monitor for three human pathogenic viruses including WeSt.Nile virus (WNV), WeSt.rn equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires coSt.y, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonSt.uctural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when teSt.d againSt.a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese Encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less inSt.umentally intensive than RT-qPCR and provides a more coSt.effective method of vector-borne virus surveillance.
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Reemergence of St. Louis Encephalitis Virus, California, 2015
Centers for Disease Control and Prevention, 2016Co-Authors: Gregory S. White, William K. Reisen, Sandra García, Ying Fang, Kelly Symmes, Pu Sun, Cody Steiner, Kirk Smith, Lark L. CoffeyAbstract:St. Louis Encephalitis virus infection was detected in summer 2015 in southern California after an 11-year absence, concomitant with an Arizona outbreak. Sequence comparisons showed close identity of California and Arizona isolates with 2005 Argentine isolates, suggeSt.ng introduction from South America and underscoring the value of continued arbovirus surveillance
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multiplex qrt pcr for the detection of weSt.rn equine encephalomyelitis St.Louis Encephalitis and weSt.nile viral rna in mosquito pools diptera culicidae
Journal of Medical Entomology, 2015Co-Authors: Aaron C. Brault, Ying Fang, William K. ReisenAbstract:Following the introduction of WeSt.Nile virus into California during the summer of 2003, public health and vector control programs expanded surveillance efforts and were in need of diagnoSt.cs capable of rapid, sensitive, and specific detection of arbovirus infections of mosquitoes to inform decision support for intervention. Development of a multiplex TaqMan or real-time semiquantitative reverse transcription polymerase chain reaction (RT-PCR) assay in which three virus specific primer–probe sets were used in the same reaction is described herein for the detection of weSt.rn equine encephalomyelitis, St. Louis Encephalitis and WeSt.Nile viral RNA. Laboratory validation and field data from 10 transmission seasons are reported. The comparative sensitivity and specificity of this multiplex assay to singleplex RT-PCR as well as an antigen detection (rapid analyte measurement platform) and St.ndard plaque assays indicate this assay to be rapid and useful in providing mosquito infection data to eSt.mate outbreak risk.
Sarah S. Wheeler - One of the best experts on this subject based on the ideXlab platform.
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Surveys for Antibodies AgainSt.Mosquitoborne Encephalitis Viruses in California Birds, 1996-2013.
Vector-borne and Zoonotic Diseases, 2016Co-Authors: William K. Reisen, Sarah S. WheelerAbstract:AbSt.act From 1996 through 2013, 54,546 individual birds comprising 152 species and 7 orders were banded, bled, and released at four St.dy areas within California, from which 28,388 additional serum samples were collected at one or more recapture encounters. Of these, 142, 99, and 1929 birds from 41 species were positive for neutralizing antibodies againSt.weSt.rn equine encephalomyelitis virus (WEEV), St. Louis Encephalitis virus (SLEV), or WeSt.Nile virus (WNV) at initial capture or recapture, respectively. Overall, 83% of the positive serum samples were collected from five species: House Finch, House Sparrow, Mourning Dove, California Quail, and WeSt.rn Scrub-Jay. Temporal data supported concurrent arbovirus surveillance and documented the disappearance of birds positive for WEEV in 2008 and SLEV in 2003 and the appearance of birds positive for WNV after its invasion in 2003. Results of these serosurveys agreed well with the hoSt.selection patterns of the Culex vectors as described from bloodmeal seque...
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Surveillance for WeSt.rn Equine Encephalitis, St. Louis Encephalitis, and WeSt.Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification.
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and teSt.ng 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 diSt.icts in California routinely monitor for three human pathogenic viruses including WeSt.Nile virus (WNV), WeSt.rn equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires coSt.y, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonSt.uctural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of
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surveillance for weSt.rn equine Encephalitis St.Louis Encephalitis and weSt.nile viruses using reverse transcription loop mediated isothermal amplification
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and teSt.ng 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 diSt.icts in California routinely monitor for three human pathogenic viruses including WeSt.Nile virus (WNV), WeSt.rn equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires coSt.y, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonSt.uctural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when teSt.d againSt.a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese Encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less inSt.umentally intensive than RT-qPCR and provides a more coSt.effective method of vector-borne virus surveillance.
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Role of California (Callipepla californica) and Gambel's (Callipepla gambelii) quail in the ecology of mosquito-borne Encephalitis viruses in California, USA.
Vector-Borne and Zoonotic Diseases, 2006Co-Authors: William K. Reisen, Vincent M Martinez, Sarah S. Wheeler, Sandra García, Ying Fang, Siranoosh Ashtari, Brian D. CarrollAbstract:Gambel's and California quail were infected repeatedly whenever weSt.rn 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 St.dies with chicks, juveniles, and adults of both quail species using sympatric St.ains of WEEV, SLEV, and WNV indicated that only immature birds were competent hoSt. for WEEV, producing viremias sufficiently elevated to efficiently infect Culex tarsalis mosquitoes. Quail were less competent hoSt. for WNV and were incompetent for SLEV. Large populations of quail that frequently are infected with SLEV or WNV, but produce low to moderate viremias, may serve as dead end hoSt. for these viruses. Due to their abundance ...
Robert J. Meagher - One of the best experts on this subject based on the ideXlab platform.
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Surveillance for WeSt.rn Equine Encephalitis, St. Louis Encephalitis, and WeSt.Nile Viruses Using Reverse Transcription Loop-Mediated Isothermal Amplification.
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and teSt.ng 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 diSt.icts in California routinely monitor for three human pathogenic viruses including WeSt.Nile virus (WNV), WeSt.rn equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires coSt.y, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonSt.uctural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of
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surveillance for weSt.rn equine Encephalitis St.Louis Encephalitis and weSt.nile viruses using reverse transcription loop mediated isothermal amplification
PLOS ONE, 2016Co-Authors: Sarah S. Wheeler, Cameron Ball, Stanley A. Langevin, Lark L. Coffey, Ying Fang, Robert J. MeagherAbstract:Collection of mosquitoes and teSt.ng 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 diSt.icts in California routinely monitor for three human pathogenic viruses including WeSt.Nile virus (WNV), WeSt.rn equine Encephalitis virus (WEEV), and St. Louis Encephalitis virus (SLEV). Reverse transcription quantitative polymerase chain reaction (RT-qPCR) offers highly sensitive and specific detection of these three viruses in a single multiplex reaction, but this technique requires coSt.y, specialized equipment that is generally only available in centralized public health laboratories. We report the use of reverse transcription loop-mediated isothermal amplification (RT-LAMP) to detect WNV, WEEV, and SLEV RNA extracted from pooled mosquito samples collected in California, including novel primer sets for specific detection of WEEV and SLEV, targeting the nonSt.uctural protein 4 (nsP4) gene of WEEV and the 3’ untranslated region (3’-UTR) of SLEV. Our WEEV and SLEV RT-LAMP primers allowed detection of <0.1 PFU/reaction of their respective targets in <30 minutes, and exhibited high specificity without cross reactivity when teSt.d againSt.a panel of alphaviruses and flaviviruses. Furthermore, the SLEV primers do not cross-react with WNV, despite both viruses being closely related members of the Japanese Encephalitis virus complex. The SLEV and WEEV primers can also be combined in a single RT-LAMP reaction, with discrimination between amplicons by melt curve analysis. Although RT-qPCR is approximately one order of magnitude more sensitive than RT-LAMP for all three targets, the RT-LAMP technique is less inSt.umentally intensive than RT-qPCR and provides a more coSt.effective method of vector-borne virus surveillance.
Diaz, Luis Adrian - One of the best experts on this subject based on the ideXlab platform.
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Vector competence for WeSt.Nile virus and St. Louis Encephalitis virus (flavivirus) of three tick species of the genus Amblyomma (Acari: Ixodidae)
'American Society of Tropical Medicine and Hygiene', 2020Co-Authors: Flores, Fernando Sebastián, Zanluca Camila, Guglielmone, Alberto Alejandro, Duarte Dos Santos, Claudia N., Labruna, Marcelo B., Diaz, Luis AdrianAbstract:Many species of Amblyomma ticks are commonly found infeSt.ng wild birds in South America, where birds are important hoSt. for several arboviruses, such as WeSt.Nile virus (WNV) and St. Louis Encephalitis virus (SLEV). In this St.dy, WNV and SLEV transmission experiments were performed to evaluate the vector competence of three South American tick species: Amblyomma ovale, Amblyomma tigrinum, and Amblyomma tonelliae. Larval and nymphal ticks of each species were allowed to feed on chicks needle inoculated with WNV or SLEV. All three Amblyomma species acquired either WNV or SLEV through larval feeding, with infection rates varying from 3.1% to 100% for WNV and from 0% to 35.7% for SLEV in engorged larvae. TransSt.dial perpetuation of the viruses was demonSt.ated in the molted nymphs, with WNV infection rates varying from 0% to 33.7% and SLEV infection rates from 13.6% to 23.8%. Although nymphal ticks also acquired either virus through feeding, transSt.dial perpetuation to adult ticks was lower, with virus detection in only 3.2% of A. tigrinum and 11.5% of A. tonelliae unfed adult ticks. On the other hand, vector competence for nymphs (exposed to WNV or SLEV through larval feeding) and adult ticks (exposed to WNV or SLEV through larval or nymphal feeding) was null in all cases. Although our results indicate transSt.dial perpetuation of WNV or SLEV in the three tick species, the ticks were not competent to transmit these agents to susceptible hoSt.. The role of these ixodid tick species in the epidemiology of WNV and SLEV might be insignificant, even though at leaSt.A. ovale and A. tigrinum are frequent bird ticks in Latin America, so the virus could survive winter in the fed larvae. However, future St.dies are required to determine the implications that this could have, as well as analyze the vector competence of other common bird tick species in South America
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Culex interfor and Culex saltanensis (Diptera: Culicidae) are susceptible and competent to transmit St. Louis Encephalitis virus (Flavivirus: Flaviviridae) in central Argentina
'Oxford University Press (OUP)', 2020Co-Authors: Beranek, Mauricio Daniel, Diaz, Luis Adrian, Flores, Fernando Sebastián, Quaglia, Agustín Ignacio Eugenio, Peralta, Giovana Claudia, Stein Marina, Almiron, Walter Ricardo, Contigiani De Minio, Marta SilviaAbstract:Background: St. Louis Encephalitis virus (SLEV) is endemic and autochthonous on the American continent. Culex pipiens quinquefasciatus is a vector of SLEV; however, Culex interfor and Culex saltanensis have also been found to be naturally infected with SLEV. The aim of this St.dy was to determine the vector competence of C. interfor and C. saltanensis for SLEV from Argentina compared with C. p. quinquefasciatus. Culex genus is Cx.?Methods: Female of the Culex species were orally infected by feeding on viraemic chicks that had been inoculated with SLEV. Abdomens, legs and saliva blood-fed mosquitoes were analysed by viral plaque assay.Results: Mosquitoes were susceptible to orally acquired infection, dissemination and transmission of SLEV in the saliva.Conclusions: Our results demonSt.ate that C. saltanensis and C. interfor are susceptible to SLEV and competent for its transmission.Fil: Beranek, Mauricio Daniel. Universidad Nacional de Cordoba. Facultad de Medicina. InSt.tuto de Virología; ArgentinaFil: Quaglia, AguSt.n Ignacio Eugenio. Universidad Nacional de Cordoba. Facultad de Medicina. InSt.tuto de Virología; ArgentinaFil: Peralta, Giovana Claudia. Universidad Nacional de Cordoba. Facultad de Medicina. InSt.tuto de Virología; ArgentinaFil: Flores, Fernando SebaSt.án. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. InSt.tuto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. InSt.tuto de Ciencias Veterinarias del Litoral; ArgentinaFil: St.in, Marina. Universidad Nacional del NordeSt.. InSt.tuto de Medicina Regional. Área de Entomología; ArgentinaFil: Diaz, Luis Adrian. Universidad Nacional de Cordoba. Facultad de Medicina. InSt.tuto de Virología; ArgentinaFil: Almiron, Walter Ricardo. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. InSt.tuto de InveSt.gaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. InSt.tuto de InveSt.gaciones Biológicas y Tecnológicas; ArgentinaFil: Contigiani de Minio, Marta Silvia. Universidad Nacional de Córdoba. Facultad de Medicina. InSt.tuto de Virología Dr. J. M. Vanella; Argentin
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Vector competence for WeSt.Nile virus and St. Louis Encephalitis virus (flavivirus) of three tick species of the genus Amblyomma (Acari: Ixodidae)
'American Society of Tropical Medicine and Hygiene', 2020Co-Authors: Flores, Fernando Sebastián, Zanluca Camila, Guglielmone, Alberto Alejandro, Duarte Dos Santos, Claudia N., Labruna, Marcelo B., Diaz, Luis AdrianAbstract:Many species of Amblyomma ticks are commonly found infeSt.ng wild birds in South America, where birds are important hoSt. for several arboviruses, such as WeSt.Nile virus (WNV) and St. Louis Encephalitis virus (SLEV). In this St.dy, WNV and SLEV transmission experiments were performed to evaluate the vector competence of three South American tick species: Amblyomma ovale, Amblyomma tigrinum, and Amblyomma tonelliae. Larval and nymphal ticks of each species were allowed to feed on chicks needle inoculated with WNV or SLEV. All three Amblyomma species acquired either WNV or SLEV through larval feeding, with infection rates varying from 3.1% to 100% for WNV and from 0% to 35.7% for SLEV in engorged larvae. TransSt.dial perpetuation of the viruses was demonSt.ated in the molted nymphs, with WNV infection rates varying from 0% to 33.7% and SLEV infection rates from 13.6% to 23.8%. Although nymphal ticks also acquired either virus through feeding, transSt.dial perpetuation to adult ticks was lower, with virus detection in only 3.2% of A. tigrinum and 11.5% of A. tonelliae unfed adult ticks. On the other hand, vector competence for nymphs (exposed to WNV or SLEV through larval feeding) and adult ticks (exposed to WNV or SLEV through larval or nymphal feeding) was null in all cases. Although our results indicate transSt.dial perpetuation of WNV or SLEV in the three tick species, the ticks were not competent to transmit these agents to susceptible hoSt.. The role of these ixodid tick species in the epidemiology of WNV and SLEV might be insignificant, even though at leaSt.A. ovale and A. tigrinum are frequent bird ticks in Latin America, so the virus could survive winter in the fed larvae. However, future St.dies are required to determine the implications that this could have, as well as analyze the vector competence of other common bird tick species in South America.Fil: Flores, Fernando SebaSt.án. Universidad Nacional de Córdoba. Facultad de Medicina; ArgentinaFil: Zanluca, Camila. InSt.tuto Carlos Chagas, Curitiba;Fil: Guglielmone, Alberto Alejandro. InSt.tuto Nacional de Tecnología Agropecuaria Eea, Rafaela; ArgentinaFil: Duarte dos Santos, Claudia N.. InSt.tuto Carlos Chagas, Curitiba;Fil: Labruna, Marcelo B.. Universidade de Sao Paulo; BrasilFil: Diaz, Luis Adrian. Universidad Nacional de Córdoba. Facultad de Medicina; Argentina. Universidad Nacional de Córdoba; Argentin
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Exposure of raptors in central Argentina to St. Louis Encephalitis and WeSt.Nile viruses
'The Raptor Research Foundation Inc.', 2020Co-Authors: Mansilla, Ana Paula, Solaro Claudina, Orozco Valor, Paula Maiten, Grande, Juan Manuel, Sarasola, José Hernán, Diaz, Luis AdrianAbstract:Arthropod-borne viruses are the moSt.important emerging viruses worldwide. Saint Louis Encephalitis (SLEV) and WeSt.Nile (WNV) viruses are vectored by Culex mosquitoes and amplified by several bird species. We carried out an extensive retrospective serosurvey St.dy to analyze the exposure of free ranging birds of prey to SLEV and WNV in central Argentina. A total of 523 plasma samples were analyzed by Plaque Reduction Neutralization TeSt.(PRNT) for both viruses. Samples belonging to eight raptor species were collected from 2008 to 2015. Of the individuals teSt.d for WNV, 81.5% of the Swainson´s Hawks (Buteo swainsoni) were positive. In the other hand, 20.8% of the Black Vultures (Coragyps atratus), 25% of the Southern Caracaras (Caracara plancus) and only 0.3% of the American KeSt.els (Falco sparverius) had detectable neutralizing antibodies againSt.SLEV. Only one Swainson´s Hawk was positive for both viruses (3.7%). No neutralizing antibodies were found in samples from Turkey Vulture (Cathartes aura), Chimango Caracara (Milvago chimango), Burrowing Owl (Athene cunicularia) and Ferruginous Pygmy-Owl (Glaucidium brasilianum). Our results confirm SLEV and WNV circulation in resident and migratory populations of raptors in central Argentina, despite the fact that seroprevalence was variable among species. These findings suggeSt.the need of further St.dies regarding circulation and ecological characterization of these viruses in bird communities in Argentina.Fil: Mansilla, Ana Paula. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Solaro, Claudina. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Orozco Valor, Paula Maiten. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Grande, Juan Manuel. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Sarasola, José Hernán. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. InSt.tuto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Diaz, Luis Adrian. Universidad Nacional de Córdoba. Facultad de Medicina. InSt.tuto de Virología Dr. J. M. Vanella; Argentina. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. InSt.tuto de InveSt.gaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. InSt.tuto de InveSt.gaciones Biológicas y Tecnológicas; Argentin
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Reemergence of St. Louis Encephalitis virus in the Americas
'Centers for Disease Control and Prevention (CDC)', 2018Co-Authors: Diaz, Luis Adrian, Coffey, Lark L, Burkett-cadena Nathan, Day, Jonathan F.Abstract:We summarize and analyze hiSt.rical and current data regarding the reemergence of St. Louis Encephalitis virus (SLEV; genus Flavivirus) in the Americas. HiSt.rically, SLEV caused Encephalitis outbreaks in the United St.tes; however, it was not considered a public health concern in the reSt.of the Americas. After the introduction of WeSt.Nile virus in 1999, activity of SLEV decreased considerably in the United St.tes. During 2014–2015, SLEV caused a human outbreak in Arizona and caused isolated human cases in California in 2016 and 2017. Phylogenetic analyses indicate that the emerging SLEV in the weSt.rn United St.tes is related to the epidemic St.ains isolated during a human Encephalitis outbreak in Córdoba, Argentina, in 2005. Ecoepidemiologic St.dies suggeSt.that the emergence of SLEV in Argentina was caused by the introduction of a more pathogenic St.ain and increasing populations of the eared dove (amplifying hoSt..Fil: Diaz, Luis Adrian. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de InveSt.gaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. InSt.tuto de InveSt.gaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. InSt.tuto de InveSt.gaciones Biológicas y Tecnológicas; ArgentinaFil: Coffey, Lark L.. University of California at Davis; ESt.dos UnidosFil: Burkett-Cadena, Nathan. University of Florida; ESt.dos UnidosFil: Day, Jonathan F.. University of Florida; ESt.dos Unido