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The Veterinary clinics of North America. Equine practice2001; 16(3); 427-441; doi: 10.1016/s0749-0739(17)30087-1

West Nile encephalitis.

Abstract: WNV encephalitis in horses, previously reported in Africa, Asia, and Europe, occurred for the first time in the Western Hemisphere in 1999. The causative agent, WNV, is a flavivirus maintained in nature by a bird-mosquito cycle. The disease in horses is manifested primarily by ataxia of variable severity. Outbreaks of encephalitis may have a case fatality rate in excess of 40%, although this virus infection is inapparent in some horses. Early evidence indicates that WNV has overwintered in the northeastern United States and poses a threat for future disease occurrences in horses. No vaccine is available to protect against WNV infection in horses; disease control is predicated on mosquito abatement.
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Publication Date: 2001-02-24 PubMed ID: 11219341DOI: 10.1016/s0749-0739(17)30087-1Google Scholar: Lookup
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Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This research focuses on West Nile Virus (WNV) encephalitis in horses. It discusses the virus’ history, its cycle in nature, disease traits, and risk factors, highlighting the lack of effective vaccines and emphasizing the importance of mosquito control for disease prevention.

West Nile Virus

  • The study puts emphasis on West Nile Virus (WNV) encephalitis in horses, which was reported in Africa, Asia, and Europe and first emerged in the Western Hemisphere in 1999.
  • WNV is described as a flavivirus that undergoes a cycle in nature maintained by birds and mosquitoes.

Disease Manifestation and Case Rate

  • The disease’s primary manifestation in horses is identified as ataxia of varying severity. Ataxia refers to a lack of voluntary coordination of muscle movements which typically affects the animals’ gait stability.
  • The research states that outbreaks of the disease can exhibit a case fatality rate exceeding 40%. This implies that in an outbreak scenario, more than 40% of the infected horses might not survive.
  • Interestingly, the research also notes that some horses might show no apparent symptoms of the infection. This could mean that the virus behaves differently in different subjects, or that some horses may have a level of natural resistance or immunity to the disease.

Future Disease Occurrences

  • According to the research, preliminary indications suggest that WNV has overwintered in the northeastern United States, rendering it a potential threat for future outbreaks in horses. Overwintering means that the virus has managed to survive the winter period. This observation supports the plausibility of recurring disease events.
  • In the absence of an available vaccine against WNV infection in horses, the research underscores the significance of mosquito control in the management and mitigation of WNV encephalitis.

Cite This Article

APA
Ostlund EN, Andresen JE, Andresen M. (2001). West Nile encephalitis. Vet Clin North Am Equine Pract, 16(3), 427-441. https://doi.org/10.1016/s0749-0739(17)30087-1

Publication

The Veterinary clinics of North America. Equine practice
ISSN: 0749-0739
NlmUniqueID: 8511904
Country: United States
Language: English
Volume: 16
Issue: 3
Pages: 427-441

Researcher Affiliations

Ostlund, E N
  • Equine and Ovine Viruses Section, Diagnostic Virology Laboratory, National Veterinary Services Laboratories, United States Department of Agriculture , Ames, Iowa, USA.
Andresen, J E
    Andresen, M

      MeSH Terms

      • Animals
      • Antibodies, Viral / analysis
      • Brain / virology
      • Disease Outbreaks / veterinary
      • Horse Diseases / diagnosis
      • Horse Diseases / epidemiology
      • Horse Diseases / therapy
      • Horses
      • Mosquito Control
      • United States / epidemiology
      • West Nile Fever / diagnosis
      • West Nile Fever / epidemiology
      • West Nile Fever / therapy
      • West Nile Fever / veterinary

      Citations

      This article has been cited 21 times.
      1. Gothe LMR, Ganzenberg S, Ziegler U, Obiegala A, Lohmann KL, Sieg M, Vahlenkamp TW, Groschup MH, Hörügel U, Pfeffer M. Horses as Sentinels for the Circulation of Flaviviruses in Eastern-Central Germany. Viruses 2023 Apr 30;15(5).
        doi: 10.3390/v15051108pubmed: 37243194google scholar: lookup
      2. García-Bocanegra I, Franco JJ, León CI, Barbero-Moyano J, García-Miña MV, Fernández-Molera V, Gómez MB, Cano-Terriza D, Gonzálvez M. High exposure of West Nile virus in equid and wild bird populations in Spain following the epidemic outbreak in 2020. Transbound Emerg Dis 2022 Nov;69(6):3624-3636.
        doi: 10.1111/tbed.14733pubmed: 36222172google scholar: lookup
      3. Ganzenberg S, Sieg M, Ziegler U, Pfeffer M, Vahlenkamp TW, Hörügel U, Groschup MH, Lohmann KL. Seroprevalence and Risk Factors for Equine West Nile Virus Infections in Eastern Germany, 2020. Viruses 2022 May 30;14(6).
        doi: 10.3390/v14061191pubmed: 35746662google scholar: lookup
      4. Goodrich EL, McLean A, Guarino C. A Pilot Serosurvey for Selected Pathogens in Feral Donkeys (Equus asinus). Animals (Basel) 2020 Oct 2;10(10).
        doi: 10.3390/ani10101796pubmed: 33023217google scholar: lookup
      5. More S, Bøtner A, Butterworth A, Calistri P, Depner K, Edwards S, Garin-Bastuji B, Good M, Gortázar Schmidt C, Michel V, Miranda MA, Nielsen SS, Raj M, Sihvonen L, Spoolder H, Stegeman JA, Thulke HH, Velarde A, Willeberg P, Winckler C, Baldinelli F, Broglia A, Dhollander S, Beltrán-Beck B, Kohnle L, Morgado J, Bicout D. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): West Nile fever. EFSA J 2017 Aug;15(8):e04955.
        doi: 10.2903/j.efsa.2017.4955pubmed: 32625621google scholar: lookup
      6. Martins LC, Silva EVPD, Casseb LMN, Silva SPD, Cruz ACR, Pantoja JAS, Medeiros DBA, Martins Filho AJ, Cruz EDRMD, Araújo MTF, Cardoso JF, Cunha MACRD, Almada GL, Romano APM, Santos MGDP, Rodrigues GAP, Chiang JO, Quaresma JAS, Carvalho VL, Vasconcelos PFDC. First isolation of West Nile virus in Brazil. Mem Inst Oswaldo Cruz 2019 Jan 17;114:e180332.
        doi: 10.1590/0074-02760180332pubmed: 30672980google scholar: lookup
      7. Mulatti P, Mazzucato M, Montarsi F, Ciocchetta S, Capelli G, Bonfanti L, Marangon S. Retrospective space-time analysis methods to support West Nile virus surveillance activities. Epidemiol Infect 2015 Jan;143(1):202-13.
        doi: 10.1017/S0950268814000442pubmed: 24641869google scholar: lookup
      8. Brown EB, Adkin A, Fooks AR, Stephenson B, Medlock JM, Snary EL. Assessing the risks of West Nile virus-infected mosquitoes from transatlantic aircraft: implications for disease emergence in the United Kingdom. Vector Borne Zoonotic Dis 2012 Apr;12(4):310-20.
        doi: 10.1089/vbz.2010.0176pubmed: 22217181google scholar: lookup
      9. Franson JC, Hofmeister EK, Collins GH, Dusek RJ. Seroprevalence of West Nile virus in feral horses on Sheldon National Wildlife Refuge, Nevada, United States. Am J Trop Med Hyg 2011 Apr;84(4):637-40.
        doi: 10.4269/ajtmh.2011.10-0467pubmed: 21460023google scholar: lookup
      10. Ward MP, Wittich CA, Fosgate G, Srinivasan R. Environmental risk factors for equine West Nile virus disease cases in Texas. Vet Res Commun 2009 Jun;33(5):461-71.
        doi: 10.1007/s11259-008-9192-1pubmed: 19031106google scholar: lookup
      11. Epp T, Waldner C, West K, Townsend H. Factors associated with West Nile virus disease fatalities in horses. Can Vet J 2007 Nov;48(11):1137-45.
        pubmed: 18050794
      12. Mongoh MN, Khaitsa ML, Dyer NW. Environmental and ecological determinants of West Nile virus occurrence in horses in North Dakota, 2002. Epidemiol Infect 2007 Jan;135(1):57-66.
        doi: 10.1017/S0950268806006662pubmed: 16753077google scholar: lookup
      13. Glass WG, Lim JK, Cholera R, Pletnev AG, Gao JL, Murphy PM. Chemokine receptor CCR5 promotes leukocyte trafficking to the brain and survival in West Nile virus infection. J Exp Med 2005 Oct 17;202(8):1087-98.
        doi: 10.1084/jem.20042530pubmed: 16230476google scholar: lookup
      14. Abutarbush SM, O'Connor BP, Clark C, Sampieri F, Naylor JM. Clinical West Nile virus infection in 2 horses in western Canada. Can Vet J 2004 Apr;45(4):315-7.
        pubmed: 15144104
      15. Sampathkumar P. West Nile virus: epidemiology, clinical presentation, diagnosis, and prevention. Mayo Clin Proc 2003 Sep;78(9):1137-43; quiz 1144.
        doi: 10.4065/78.9.1137pubmed: 12962168google scholar: lookup
      16. Weese JS, Baird JD, DeLay J, Kenney DG, Staempfli HR, Viel L, Parent J, Smith-Maxie L, Poma R. West Nile virus encephalomyelitis in horses in Ontario: 28 cases. Can Vet J 2003 Jun;44(6):469-73.
        pubmed: 12839240
      17. Durand B, Chevalier V, Pouillot R, Labie J, Marendat I, Murgue B, Zeller H, Zientara S. West Nile virus outbreak in horses, southern France, 2000: results of a serosurvey. Emerg Infect Dis 2002 Aug;8(8):777-82.
        doi: 10.3201/eid0808.010486pubmed: 12141961google scholar: lookup
      18. Ostlund EN, Crom RL, Pedersen DD, Johnson DJ, Williams WO, Schmitt BJ. Equine West Nile encephalitis, United States. Emerg Infect Dis 2001 Jul-Aug;7(4):665-9.
        doi: 10.3201/eid0704.010412pubmed: 11589171google scholar: lookup
      19. Hvizdos J, Hofler AC, Bradrick SS. Granular Insights on Innate and Intrinsic Immunity to Flaviviruses. Microorganisms 2025 Sep 8;13(9).
        doi: 10.3390/microorganisms13092091pubmed: 41011423google scholar: lookup
      20. Schwarz ER, Long MT. Comparison of West Nile Virus Disease in Humans and Horses: Exploiting Similarities for Enhancing Syndromic Surveillance. Viruses 2023 May 24;15(6).
        doi: 10.3390/v15061230pubmed: 37376530google scholar: lookup
      21. Khatibzadeh SM, Gold CB, Keggan AE, Perkins GA, Glaser AL, Dubovi EJ, Wagner B. West Nile virus-specific immunoglobulin isotype responses in vaccinated and infected horses. Am J Vet Res 2015 Jan;76(1):92-100.
        doi: 10.2460/ajvr.76.1.92pubmed: 25535666google scholar: lookup
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