Western Equine Encephalitis submergence: Lack of evidence for a decline in virus virulence

Naomi L. Forrester, Joan L. Kenney, Eleanor Deardorff, Eryu Wang, Scott C. Weaver

Research output: Contribution to journalArticle

32 Scopus citations


The incidence of Western Equine Encephalitis (WEE) in humans and equids peaked during the mid-20th century and has declined to fewer than 1-2 human cases annually during the past 20 years. Using the mouse model, changes in WEE virus (WEEV) virulence were investigated as a potential explanation for the decline in the number of cases. Evaluation of 10 WEEV strains representing a variety of isolation locations, hosts, and all decades from the 1940's to the 1990's yielded no evidence of a decline in virulence. These results suggest that ecological factors affecting human and equine exposure should be investigated to explain the decline in WEE.

Original languageEnglish (US)
Pages (from-to)170-172
Number of pages3
Issue number2
StatePublished - Oct 25 2008



  • Virulence
  • Western Equine Encephalitis virus

ASJC Scopus subject areas

  • Virology

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