Revue scientifique et technique (International Office of Epizootics)2015; 34(2); 491-501; doi: 10.20506/rst.34.2.2374

Alphaviral equine encephalomyelitis (Eastern, Western and Venezuelan).

Abstract: Summary Alphaviral equine encephalomyelitis is a mosquito-borne infection that causes severe neurological disease and fatalities in horses and humans in the Americas. Consequently, the equine alphaviruses (Eastern, Western and Venezuelan) are of considerable concern worldwide and are notifiable to the World Organisation for Animal Health. In addition, these diseases are considered a potent potential biological weapon, emphasising the need to develop an effective vaccine. Alphaviral equine encephalomyelitis is caused by Eastern equine encephalomyelitis virus (EEEV), Western equine encephalomyelitis virus (WEEV) or Venezuelan equine encephalomyelitis virus (VEEV), which are related members of the Alphavirus genus in the Togaviridae family. Although related, the three viruses are genetically and antigenically distinct. The disease is characterised by fever, anorexia, depression and clinical signs of encephalomyelitis, and may be fatal in up to 90% of cases, for both humans and horses, particularly in the case of EEE. Surviving horses develop lifelong immunity but may have permanent neuropathology. The aim of this paper is to analyse the scientific information available on the evolution of EEE, WEE and VEE, and any potential vaccines.
Publication Date: 2015-11-26 PubMed ID: 26601451DOI: 10.20506/rst.34.2.2374Google Scholar: Lookup
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This research paper analyzes existing scientific information about Alphaviral equine encephalomyelitis, a severe mosquito-borne infection that affects horses and humans, and the potential development of effective vaccines.

The Infection and Its Effects

  • Alphaviral equine encephalitis, characterized by fever, anorexia, depression, and clinical signs of encephalitis, is a highly detrimental infection that poses risk to both horses and humans. It is caused by one of three genetically and antigenically distinct viruses from the Alphavirus genus in the Togaviridae family: Eastern equine encephalitis virus (EEEV), Western equine encephalitis virus (WEEV), or Venezuelan equine encephalitis virus (VEEV).
  • The disease can result in fatalities in up to 90% cases. Even if horses survive the infection, they can still suffer from permanent neuropathology, though they do develop lifelong immunity.

So far, concerning these Diseases

  • It is noteworthy that these mosquito-borne diseases are particularly prevalent in the Americas and are of considerable global concern given their severity. As a result, case notifications are mandatory to the World Organisation for Animal Health.
  • Apart from their natural impact, these viruses carry the potential to be used as biological weapons, further underscoring the importance of developing an effective vaccine.

The Purpose of the Research

  • The paper’s objective is to evaluate and synthesize the presently available scientific data about the evolution of these three forms of equine encephalomyelitis: Eastern, Western, and Venezuelan. It also aims to address ongoing research efforts towards potential vaccines.

Cite This Article

Aru00e9chiga-Ceballos N, Aguilar-Setiu00e9n A. (2015). Alphaviral equine encephalomyelitis (Eastern, Western and Venezuelan). Rev Sci Tech, 34(2), 491-501.


ISSN: 0253-1933
NlmUniqueID: 8712301
Country: France
Language: English
Volume: 34
Issue: 2
Pages: 491-501

Researcher Affiliations

Aru00e9chiga-Ceballos, N
    Aguilar-Setiu00e9n, A

      MeSH Terms

      • Alphavirus
      • Americas
      • Animals
      • Encephalomyelitis, Equine / virology
      • Horse Diseases
      • Horses / virology
      • Zoonoses


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