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Foss L, Feiszli T, Kramer VL, Reisen WK, Padgett K. Epidemic versus endemic West Nile virus dead bird surveillance in California: Changes in sensitivity and focus. PLoS One 2023; 18:e0284039. [PMID: 37023091 PMCID: PMC10079120 DOI: 10.1371/journal.pone.0284039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 03/21/2023] [Indexed: 04/07/2023] Open
Abstract
Since 2003, the California West Nile virus (WNV) dead bird surveillance program (DBSP) has monitored publicly reported dead birds for WNV surveillance and response. In the current paper, we compared DBSP data from early epidemic years (2004-2006) with recent endemic years (2018-2020), with a focus on specimen collection criteria, county report incidence, bird species selection, WNV prevalence in dead birds, and utility of the DBSP as an early environmental indicator of WNV. Although fewer agencies collected dead birds in recent years, most vector control agencies with consistent WNV activity continued to use dead birds as a surveillance tool, with streamlined operations enhancing efficiency. The number of dead bird reports was approximately ten times greater during 2004-2006 compared to 2018-2020, with reports from the Central Valley and portions of Southern California decreasing substantially in recent years; reports from the San Francisco Bay Area decreased less dramatically. Seven of ten counties with high numbers of dead bird reports were also high human WNV case burden areas. Dead corvid, sparrow, and quail reports decreased the most compared to other bird species reports. West Nile virus positive dead birds were the most frequent first indicators of WNV activity by county in 2004-2006, followed by positive mosquitoes; in contrast, during 2018-2020 mosquitoes were the most frequent first indicators followed by dead birds, and initial environmental WNV detections occurred later in the season during 2018-2020. Evidence for WNV impacts on avian populations and susceptibility are discussed. Although patterns of dead bird reports and WNV prevalence in tested dead birds have changed, dead birds have endured as a useful element within our multi-faceted WNV surveillance program.
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Affiliation(s)
- Leslie Foss
- Vector-Borne Disease Section, California Department of Public Health, Richmond, California, United States of America
| | - Tina Feiszli
- Vector-Borne Disease Section, California Department of Public Health, Richmond, California, United States of America
| | - Vicki L. Kramer
- Vector-Borne Disease Section, California Department of Public Health, Sacramento, California, United States of America
| | - William K. Reisen
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, CA, United States of America
| | - Kerry Padgett
- Vector-Borne Disease Section, California Department of Public Health, Richmond, California, United States of America
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2
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Luethy D. Eastern, Western, and Venezuelan Equine Encephalitis and West Nile Viruses: Clinical and Public Health Considerations. Vet Clin North Am Equine Pract 2023; 39:99-113. [PMID: 36737290 DOI: 10.1016/j.cveq.2022.11.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The continued recognition and emergence of alphavirus and flavivirus diseases is a growing veterinary and public health concern. As the global environment continues to change, mosquito-borne diseases will continue to evolve and expand. Continued development of readily available vaccines for the prevention of these diseases in humans and animals is essential to controlling epizootics of these diseases. Further research into effective antiviral treatments is also sorely needed. This article describes equine encephalitis viruses with a focus on clinical and public health considerations.
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Affiliation(s)
- Daniela Luethy
- Large Animal Internal Medicine, Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, PO Box 100136, Gainesville, FL 32610, USA.
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3
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McMillan JR, Hamer GL, Levine RS, Mead DG, Waller LA, Goldberg TL, Walker ED, Brawn JD, Ruiz MO, Kitron U, Vazquez-Prokopec G. Multi-Year Comparison of Community- and Species-Level West Nile Virus Antibody Prevalence in Birds from Atlanta, Georgia and Chicago, Illinois, 2005-2016. Am J Trop Med Hyg 2023; 108:366-376. [PMID: 36572005 PMCID: PMC9896344 DOI: 10.4269/ajtmh.21-1086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 09/26/2022] [Indexed: 12/27/2022] Open
Abstract
West Nile virus (WNV) is prevalent in the United States but shows considerable variation in transmission intensity. The purpose of this study was to compare patterns of WNV seroprevalence in avian communities sampled in Atlanta, Georgia and Chicago, Illinois during a 12-year period (Atlanta 2010-2016; Chicago 2005-2012) to reveal regional patterns of zoonotic activity of WNV. WNV antibodies were measured in wild bird sera using ELISA and serum neutralization methods, and seroprevalence among species, year, and location of sampling within each city were compared using binomial-distributed generalized linear mixed-effects models. Seroprevalence was highest in year-round and summer-resident species compared with migrants regardless of region; species explained more variance in seroprevalence within each city. Northern cardinals were the species most likely to test positive for WNV in each city, whereas all other species, on average, tested positive for WNV in proportion to their sample size. Despite similar patterns of seroprevalence among species, overall seroprevalence was higher in Atlanta (13.7%) than in Chicago (5%). Location and year of sampling had minor effects, with location explaining more variation in Atlanta and year explaining more variation in Chicago. Our findings highlight the nature and magnitude of regional differences in WNV urban ecology.
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Affiliation(s)
- Joseph R. McMillan
- Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia
| | - Gabriel L. Hamer
- Department of Entomology, Texas A&M University, College Station, Texas
| | - Rebecca S. Levine
- Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia
| | - Daniel G. Mead
- Southeastern Cooperative Wildlife Disease Study, University of Georgia, Athens, Georgia
| | - Lance A. Waller
- Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia;,Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, Georgia
| | - Tony L. Goldberg
- Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin–Madison, Madison, Wisconsin
| | - Edward D. Walker
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan
| | - Jeffrey D. Brawn
- Department of Natural Resources and Environmental Sciences, University of Illinois Champaign–Urbana, Urbana, Illinois
| | - Marilyn O. Ruiz
- Department of Pathobiology, University of Illinois Champaign–Urbana, Urbana, Illinois
| | - Uriel Kitron
- Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia;,Department of Environmental Sciences, Emory University, Atlanta, Georgia
| | - Gonzalo Vazquez-Prokopec
- Program in Population Biology, Ecology and Evolution, Emory University, Atlanta, Georgia;,Department of Environmental Sciences, Emory University, Atlanta, Georgia,Address correspondence to Gonzalo Vazquez-Prokopec, Department of Environmental Sciences, Emory University, 400 Dowman Dr., Math and Science Center, 5th Floor, Suite E530, Atlanta, GA 30322. E-mail:
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4
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Deviche P, Sweazea K, Angelier F. Past and future: Urbanization and the avian endocrine system. Gen Comp Endocrinol 2023; 332:114159. [PMID: 36368439 DOI: 10.1016/j.ygcen.2022.114159] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 10/18/2022] [Accepted: 11/02/2022] [Indexed: 11/10/2022]
Abstract
Urban environments are evolutionarily novel and differ from natural environments in many respects including food and/or water availability, predation, noise, light, air quality, pathogens, biodiversity, and temperature. The success of organisms in urban environments requires physiological plasticity and adjustments that have been described extensively, including in birds residing in geographically and climatically diverse regions. These studies have revealed a few relatively consistent differences between urban and non-urban conspecifics. For example, seasonally breeding urban birds often develop their reproductive system earlier than non-urban birds, perhaps in response to more abundant trophic resources. In most instances, however, analyses of existing data indicate no general pattern distinguishing urban and non-urban birds. It is, for instance, often hypothesized that urban environments are stressful, yet the activity of the hypothalamus-pituitary-adrenal axis does not differ consistently between urban and non-urban birds. A similar conclusion is reached by comparing blood indices of metabolism. The origin of these disparities remains poorly understood, partly because many studies are correlative rather than aiming at establishing causality, which effectively limits our ability to formulate specific hypotheses regarding the impacts of urbanization on wildlife. We suggest that future research will benefit from prioritizing mechanistic approaches to identify environmental factors that shape the phenotypic responses of organisms to urbanization and the neuroendocrine and metabolic bases of these responses. Further, it will be critical to elucidate whether factors affect these responses (a) cumulatively or synergistically; and (b) differentially as a function of age, sex, reproductive status, season, and mobility within the urban environment. Research to date has used various taxa that differ greatly not only phylogenetically, but also with regard to ecological requirements, social systems, propensity to consume anthropogenic food, and behavioral responses to human presence. Researchers may instead benefit from standardizing approaches to examine a small number of representative models with wide geographic distribution and that occupy diverse urban ecosystems.
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Affiliation(s)
- Pierre Deviche
- School of Life Sciences, Arizona State University, Tempe, AZ, USA.
| | - Karen Sweazea
- College of Health Solutions, Arizona State University, Phoenix, AZ, USA
| | - Frederic Angelier
- Centre d'Etudes Biologiques de Chizé, UMR7372, CNRS - La Rochelle Universite, Villiers en Bois, France
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5
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Danforth ME, Snyder RE, Feiszli T, Bullick T, Messenger S, Hanson C, Padgett K, Coffey LL, Barker CM, Reisen WK, Kramer VL. Epidemiologic and environmental characterization of the Re-emergence of St. Louis Encephalitis Virus in California, 2015-2020. PLoS Negl Trop Dis 2022; 16:e0010664. [PMID: 35939506 PMCID: PMC9387929 DOI: 10.1371/journal.pntd.0010664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/18/2022] [Accepted: 07/15/2022] [Indexed: 11/18/2022] Open
Abstract
St. Louis encephalitis virus (SLEV) is an endemic flavivirus in the western and southeastern United States, including California. From 1938 to 2003, the virus was detected annually in California, but after West Nile virus (WNV) arrived in 2003, SLEV was not detected again until it re-emerged in Riverside County in 2015. The re-emerging virus in California and other areas of the western US is SLEV genotype III, which previously had been detected only in Argentina, suggesting a South American origin. This study describes SLEV activity in California since its re-emergence in 2015 and compares it to WNV activity during the same period. From 2015 to 2020, SLEV was detected in 1,650 mosquito pools and 26 sentinel chickens, whereas WNV was detected concurrently in 18,108 mosquito pools and 1,542 sentinel chickens from the same samples. There were 24 reported human infections of SLEV in 10 California counties, including two fatalities (case fatality rate: 8%), compared to 2,469 reported human infections of WNV from 43 California counties, with 143 fatalities (case fatality rate: 6%). From 2015 through 2020, SLEV was detected in 17 (29%) of California's 58 counties, while WNV was detected in 54 (93%). Although mosquitoes and sentinel chickens have been tested routinely for arboviruses in California for over fifty years, surveillance has not been uniform throughout the state. Of note, since 2005 there has been a steady decline in the use of sentinel chickens among vector control agencies, potentially contributing to gaps in SLEV surveillance. The incidence of SLEV disease in California may have been underestimated because human surveillance for SLEV relied on an environmental detection to trigger SLEV patient screening and mosquito surveillance effort is spatially variable. In addition, human diagnostic testing usually relies on changes in host antibodies and SLEV infection can be indistinguishable from infection with other flaviviruses such as WNV, which is more prevalent.
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Affiliation(s)
- Mary E. Danforth
- California Department of Public Health, Vector-Borne Disease Section, Richmond and Sacramento, California
| | - Robert E. Snyder
- California Department of Public Health, Vector-Borne Disease Section, Richmond and Sacramento, California
| | - Tina Feiszli
- California Department of Public Health, Vector-Borne Disease Section, Richmond and Sacramento, California
| | - Teal Bullick
- California Department of Public Health, Viral and Rickettsial Disease Laboratory, Richmond, California
| | - Sharon Messenger
- California Department of Public Health, Viral and Rickettsial Disease Laboratory, Richmond, California
| | - Carl Hanson
- California Department of Public Health, Viral and Rickettsial Disease Laboratory, Richmond, California
| | - Kerry Padgett
- California Department of Public Health, Vector-Borne Disease Section, Richmond and Sacramento, California
| | - Lark L. Coffey
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Christopher M. Barker
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - William K. Reisen
- Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, United States of America
| | - Vicki L. Kramer
- California Department of Public Health, Vector-Borne Disease Section, Richmond and Sacramento, California
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6
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Kunkel MR, Mead DG, Ruder MG, Nemeth NM. Our current understanding of West Nile virus in upland game birds. WILDLIFE SOC B 2022. [DOI: 10.1002/wsb.1269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Melanie R. Kunkel
- Southeastern Cooperative Wildlife Disease Study University of Georgia 589 D.W. Brooks Drive Athens 30602 GA USA
| | - Daniel G. Mead
- Southeastern Cooperative Wildlife Disease Study University of Georgia 589 D.W. Brooks Drive Athens 30602 GA USA
| | - Mark G. Ruder
- Southeastern Cooperative Wildlife Disease Study University of Georgia 589 D.W. Brooks Drive Athens 30602 GA USA
| | - Nicole M. Nemeth
- Southeastern Cooperative Wildlife Disease Study University of Georgia 589 D.W. Brooks Drive Athens 30602 GA USA
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7
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Ridenour CL, Cocking J, Poidmore S, Erickson D, Brock B, Valentine M, Roe CC, Young SJ, Henke JA, Hung KY, Wittie J, Stefanakos E, Sumner C, Ruedas M, Raman V, Seaton N, Bendik W, Hornstra O’Neill HM, Sheridan K, Centner H, Lemmer D, Fofanov V, Smith K, Will J, Townsend J, Foster JT, Keim PS, Engelthaler DM, Hepp CM. St. Louis Encephalitis Virus in the Southwestern United States: A Phylogeographic Case for a Multi-Variant Introduction Event. Front Genet 2021; 12:667895. [PMID: 34168675 PMCID: PMC8217752 DOI: 10.3389/fgene.2021.667895] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Accepted: 04/28/2021] [Indexed: 11/14/2022] Open
Abstract
Since the reemergence of St. Louis Encephalitis (SLE) Virus (SLEV) in the Southwest United States, identified during the 2015 outbreak in Arizona, SLEV has been seasonally detected within Culex spp. populations throughout the Southwest United States. Previous work revealed the 2015 outbreak was caused by an importation of SLEV genotype III, which had only been detected previously in Argentina. However, little is known about when the importation occurred or the transmission and genetic dynamics since its arrival into the Southwest. In this study, we sought to determine whether the annual detection of SLEV in the Southwest is due to enzootic cycling or new importations. To address this question, we analyzed 174 SLEV genomes (142 sequenced as part of this study) using Bayesian phylogenetic analyses to estimate the date of arrival into the American Southwest and characterize the underlying population structure of SLEV. Phylogenetic clustering showed that SLEV variants circulating in Maricopa and Riverside counties form two distinct populations with little evidence of inter-county transmission since the onset of the outbreak. Alternatively, it appears that in 2019, Yuma and Clark counties experienced annual importations of SLEV that originated in Riverside and Maricopa counties. Finally, the earliest representatives of SLEV genotype III in the Southwest form a polytomy that includes both California and Arizona samples. We propose that the initial outbreak most likely resulted from the importation of a population of SLEV genotype III variants, perhaps in multiple birds, possibly multiple species, migrating north in 2013, rather than a single variant introduced by one bird.
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Affiliation(s)
- Chase L. Ridenour
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Jill Cocking
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Samuel Poidmore
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Daryn Erickson
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Breezy Brock
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Michael Valentine
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | - Chandler C. Roe
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Steven J. Young
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ, United States
| | - Jennifer A. Henke
- Coachella Valley Mosquito and Vector Control District, Indio, CA, United States
| | - Kim Y. Hung
- Coachella Valley Mosquito and Vector Control District, Indio, CA, United States
| | - Jeremy Wittie
- Coachella Valley Mosquito and Vector Control District, Indio, CA, United States
| | | | - Chris Sumner
- Yuma County Pest Abatement District, Yuma, AZ, United States
| | - Martha Ruedas
- Yuma County Pest Abatement District, Yuma, AZ, United States
| | - Vivek Raman
- Southern Nevada Health District, Las Vegas, NV, United States
| | - Nicole Seaton
- Southern Nevada Health District, Las Vegas, NV, United States
| | - William Bendik
- Southern Nevada Health District, Las Vegas, NV, United States
| | | | - Krystal Sheridan
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | - Heather Centner
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | - Darrin Lemmer
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | - Viacheslav Fofanov
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Kirk Smith
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ, United States
| | - James Will
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ, United States
| | - John Townsend
- Vector Control Division, Maricopa County Environmental Services Department, Phoenix, AZ, United States
| | - Jeffrey T. Foster
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
| | - Paul S. Keim
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
- Translational Genomics Research Institute, Flagstaff, AZ, United States
| | | | - Crystal M. Hepp
- School of Informatics, Computing, and Cyber Systems, Northern Arizona University, Flagstaff, AZ, United States
- The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, United States
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8
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Swetnam DM, Stuart JB, Young K, Maharaj PD, Fang Y, Garcia S, Barker CM, Smith K, Godsey MS, Savage HM, Barton V, Bolling BG, Duggal N, Brault AC, Coffey LL. Movement of St. Louis encephalitis virus in the Western United States, 2014- 2018. PLoS Negl Trop Dis 2020; 14:e0008343. [PMID: 32520944 PMCID: PMC7307790 DOI: 10.1371/journal.pntd.0008343] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 06/22/2020] [Accepted: 05/02/2020] [Indexed: 11/22/2022] Open
Abstract
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 States, 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 southeastern 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 understand genetic relatedness and geographic dispersal of SLEV in the western United States since 2015, we sequenced four historical genomes (3 from California and 1 from Louisiana) and 26 contemporary SLEV genomes from mosquito pools from locations across the western US. Bayesian phylogeographic approaches were then applied to map the recent spread of SLEV. Three routes of SLEV dispersal in the western United States 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 Western United States, 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 persistence of genomes of the same ancestry. By contrast, genetic tracing suggests that all SLEV activity since 2015 in central California is the result of a single persistent SLEV introduction. The identification of natural barriers that influence SLEV dispersal enhances our understanding of arbovirus ecology in the western United States and may also support regional public health agencies in implementing more targeted vector mitigation efforts to protect their communities more effectively. Following the detection of West Nile virus in the United States, evidence of the historically endemic and closely related virus, St. Louis encephalitis virus (SLEV), dropped nationwide. However, in 2015, a novel genotype of SLEV, previously restricted to Argentina, was identified as the etiological agent of an outbreak of neurological disease in Arizona, United States. Since that time, the genotype has expanded throughout the Western United States, including into California, Nevada, Texas, Idaho, and Oregon. In this study, samples containing SLEV, provided by public health and mosquito abatement agencies, were sequenced and used in phylogenetic analyses to infer patterns of SLEV movement. Three independent routes of SLEV dispersal were identified: Arizona to Southern California, Arizona to Central California, and Arizona to all locations east of the Sierra Nevada mountains. The Sierra Nevada mountains and the Transverse Ranges appear to separate the three routes of SLEV movement, suggesting that geographic features may act as barriers to virus dispersal. Identification of patterns of SLEV dispersal can support regional public health agencies in improving vector mitigation efforts to protect their communities more effectively.
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Affiliation(s)
- Daniele M. Swetnam
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Jackson B. Stuart
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Katherine Young
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Payal D. Maharaj
- Division of Vector-borne Diseases, Centers for Disease Control, Fort Collins, Colorado, United States of America
| | - Ying Fang
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Sandra Garcia
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Christopher M. Barker
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
| | - Kirk Smith
- Maricopa County Environmental Services Department, Phoenix, Arizona, United States of America
| | - Marvin S. Godsey
- Division of Vector-borne Diseases, Centers for Disease Control, Fort Collins, Colorado, United States of America
| | - Harry M. Savage
- Division of Vector-borne Diseases, Centers for Disease Control, Fort Collins, Colorado, United States of America
| | - Vonnita Barton
- Idaho Bureau of Laboratories, Boise, Idaho, United States of America
| | - Bethany G. Bolling
- Laboratory Services Section, Texas Department of State Health Services, Austin, Texas, United States of America
| | - Nisha Duggal
- Department of Molecular Biology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, United States of America
| | - Aaron C. Brault
- Division of Vector-borne Diseases, Centers for Disease Control, Fort Collins, Colorado, United States of America
| | - Lark L. Coffey
- Department of Pathology, Microbiology, and Immunology, School of Veterinary Medicine, University of California, Davis, Davis, California, United States of America
- * E-mail:
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9
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Bergren NA, Haller S, Rossi SL, Seymour RL, Huang J, Miller AL, Bowen RA, Hartman DA, Brault AC, Weaver SC. "Submergence" of Western equine encephalitis virus: Evidence of positive selection argues against genetic drift and fitness reductions. PLoS Pathog 2020; 16:e1008102. [PMID: 32027727 PMCID: PMC7029877 DOI: 10.1371/journal.ppat.1008102] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 02/19/2020] [Accepted: 09/22/2019] [Indexed: 11/18/2022] Open
Abstract
Understanding the circumstances under which arboviruses emerge is critical for the development of targeted control and prevention strategies. This is highlighted by the emergence of chikungunya and Zika viruses in the New World. However, to comprehensively understand the ways in which viruses emerge and persist, factors influencing reductions in virus activity must also be understood. Western equine encephalitis virus (WEEV), which declined during the late 20th century in apparent enzootic circulation as well as equine and human disease incidence, provides a unique case study on how reductions in virus activity can be understood by studying evolutionary trends and mechanisms. Previously, we showed using phylogenetics that during this period of decline, six amino acid residues appeared to be positively selected. To assess more directly the effect of these mutations, we utilized reverse genetics and competition fitness assays in the enzootic host and vector (house sparrows and Culex tarsalis mosquitoes). We observed that the mutations contemporary with reductions in WEEV circulation and disease that were non-conserved with respect to amino acid properties had a positive effect on enzootic fitness. We also assessed the effects of these mutations on virulence in the Syrian-Golden hamster model in relation to a general trend of increased virulence in older isolates. However, no change effect on virulence was observed based on these mutations. Thus, while WEEV apparently underwent positive selection for infection of enzootic hosts, residues associated with mammalian virulence were likely eliminated from the population by genetic drift or negative selection. These findings suggest that ecologic factors rather than fitness for natural transmission likely caused decreased levels of enzootic WEEV circulation during the late 20th century.
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Affiliation(s)
- Nicholas A. Bergren
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Sherry Haller
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Shannan L. Rossi
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Robert L. Seymour
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Jing Huang
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Aaron L. Miller
- Department of Pediatrics, University of Texas Medical Branch, Galveston, Texas, United States of America
| | - Richard A. Bowen
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Daniel A. Hartman
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado, United States of America
| | - Aaron C. Brault
- Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, Colorado, United States of America
| | - Scott C. Weaver
- Institute for Human Infections and Immunity, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Pathology, University of Texas Medical Branch, Galveston, Texas, United States of America
- Department of Microbiology & Immunology, University of Texas Medical Branch, Galveston, Texas, United States of America
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10
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Camp JV, Nowotny N. The knowns and unknowns of West Nile virus in Europe: what did we learn from the 2018 outbreak? Expert Rev Anti Infect Ther 2020; 18:145-154. [PMID: 31914833 DOI: 10.1080/14787210.2020.1713751] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Introduction: West Nile virus (WNV) is a mosquito-borne human and animal pathogen with nearly worldwide distribution. In Europe, the virus is endemic with seasonal regional outbreaks that have increased in frequency over the last 10 years. A massive outbreak occurred across southern and central Europe in 2018 with the number of confirmed human cases increasing up to 7.2-fold from the previous year, and expanding to include previously virus-free regions.Areas covered: This review focuses on potential causes that may explain the 2018 European WNV outbreak. We discuss the role genetic, ecological, and environmental aspects may have played in the increased activity during the 2018 transmission season, summarizing the latest epidemiological and virological publications.Expert opinion: Optimal environmental conditions, specifically increased temperature, were most likely responsible for the observed outbreak. Other factors cannot be ruled out due to limited available information, including factors that may influence host/vector abundance and contact. Europe will likely experience even larger-scale outbreaks in the coming years. Increased surveillance efforts should be implemented with a focus on early-warning detection methods, and large-scale host and vector surveys should continue to fill gaps in knowledge.
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Affiliation(s)
- Jeremy V Camp
- Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Norbert Nowotny
- Viral Zoonoses, Emerging and Vector-Borne Infections Group, Institute of Virology, University of Veterinary Medicine Vienna, Vienna, Austria.,Department of Basic Medical Sciences, College of Medicine, Mohammed Bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates
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11
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Robb LL, Hartman DA, Rice L, deMaria J, Bergren NA, Borland EM, Kading RC. Continued Evidence of Decline in the Enzootic Activity of Western Equine Encephalitis Virus in Colorado. JOURNAL OF MEDICAL ENTOMOLOGY 2019; 56:584-588. [PMID: 30535264 DOI: 10.1093/jme/tjy214] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Indexed: 06/09/2023]
Abstract
Western equine encephalitis (WEE) was once prevalent and routinely isolated from mosquitoes in Colorado; however, isolations of Western equine encephalitis virus (WEEV) have not been reported from mosquito pools since the early 1990s. The objective of the present study was to test pools of Culex tarsalis (Coquillett) mosquitoes sampled from Weld County, CO, in 2016 for evidence of WEEV infection. Over 7,000 mosquitoes were tested, but none were positive for WEEV RNA. These data indicate that WEEV either was not circulating enzootically in Northern Colorado, was very rare, and would require much more extensive mosquito sampling to detect, or was heterogeneously distributed spatially and temporally and happened to not be present in the area sampled during 2016. Even though the reported incidence of WEE remains null, screening for WEEV viral RNA in mosquito vectors offers forewarning toward the detection and prevention of future outbreaks.
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Affiliation(s)
- Lucy L Robb
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Daniel A Hartman
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Lauren Rice
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Justin deMaria
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Nicholas A Bergren
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Erin M Borland
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
| | - Rebekah C Kading
- Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA
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Benzarti E, Linden A, Desmecht D, Garigliany M. Mosquito-borne epornitic flaviviruses: an update and review. J Gen Virol 2019; 100:119-132. [PMID: 30628886 DOI: 10.1099/jgv.0.001203] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
West Nile Virus, Usutu virus, Bagaza virus, Israel turkey encephalitis virus and Tembusu virus currently constitute the five flaviviruses transmitted by mosquito bites with a marked pathogenicity for birds. They have been identified as the causative agents of severe neurological symptoms, drop in egg production and/or mortalities among avian hosts. They have also recently shown an expansion of their geographic distribution and/or a rise in cases of human infection. This paper is the first up-to-date review of the pathology of these flaviviruses in birds, with a special emphasis on the difference in susceptibility among avian species, in order to understand the specificity of the host spectrum of each of these viruses. Furthermore, given the lack of a clear prophylactic approach against these viruses in birds, a meta-analysis of vaccination trials conducted to date on these animals is given to constitute a solid platform from which designing future studies.
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Affiliation(s)
- Emna Benzarti
- 1FARAH Research Center, Department of Pathology, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B43, B-4000 Liège, Belgium
| | - Annick Linden
- 2FARAH Research Center, Surveillance Network for Wildlife Diseases, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B43, B-4000 Liège, Belgium
| | - Daniel Desmecht
- 1FARAH Research Center, Department of Pathology, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B43, B-4000 Liège, Belgium
| | - Mutien Garigliany
- 1FARAH Research Center, Department of Pathology, Faculty of Veterinary Medicine, University of Liège, Sart Tilman B43, B-4000 Liège, Belgium
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13
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Predicting wildlife reservoirs and global vulnerability to zoonotic Flaviviruses. Nat Commun 2018; 9:5425. [PMID: 30575757 PMCID: PMC6303316 DOI: 10.1038/s41467-018-07896-2] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 12/05/2018] [Indexed: 11/09/2022] Open
Abstract
Flaviviruses continue to cause globally relevant epidemics and have emerged or re-emerged in regions that were previously unaffected. Factors determining emergence of flaviviruses and continuing circulation in sylvatic cycles are incompletely understood. Here we identify potential sylvatic reservoirs of flaviviruses and characterize the macro-ecological traits common to known wildlife hosts to predict the risk of sylvatic flavivirus transmission among wildlife and identify regions that could be vulnerable to outbreaks. We evaluate variability in wildlife hosts for zoonotic flaviviruses and find that flaviviruses group together in distinct clusters with similar hosts. Models incorporating ecological and climatic variables as well as life history traits shared by flaviviruses predict new host species with similar host characteristics. The combination of vector distribution data with models for flavivirus hosts allows for prediction of global vulnerability to flaviviruses and provides potential targets for disease surveillance in animals and humans.
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14
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Serosurvey for West Nile Virus Antibodies in Steller's Jays ( Cyanocitta stelleri ) Captured in Coastal California, USA. J Wildl Dis 2017; 53:582-585. [PMID: 28192043 DOI: 10.7589/2016-06-139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
West Nile virus (WNV) was first detected in New York in 1999 and, during its expansion across the continental US, southern Canada, and Mexico, members of the Corvidae (ravens, crows, magpies, and jays) were frequently infected and highly susceptible to the virus. As part of a behavioral study of Steller's Jays ( Cyanocitta stelleri ) conducted from 2011-14 in the coastal California counties of San Mateo and Santa Cruz, 380 Steller's Jays were captured and tested for antibodies to WNV. Using the wild bird immunoglobulin G enzyme linked immunoassay, we failed to detect antibodies to WNV, indicating either that there was no previous exposure to the virus or that exposed birds had died.
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