ABSTRACT

In the Americas during the 1930s, three distinct viruses were recovered from dying horses or burros that were exhibiting signs of encephalitis. Later found to be the cause of temporally associated encephalitis in humans, these viruses, eastern equine encephalitis virus (EEEV), Venezuelan equine encephalitis virus (VEEV), and western equine encephalitis virus (WEEV), were named after the diseases they cause (EEE, VEE, and WEE, respectively). The viruses are closely related single-stranded, positive-sense RNA viruses and have been assigned as members of the

Alphavirus

genus of the family

Togaviridae.