A form of arboviral encephalitis endemic to central america and the northern latitudes of south america. the causative organism (encephalitis virus, venezuelan equine) is transmitted to humans and horses via the bite of several mosquito species. human viral infection may be asymptomatic or remain restricted to a mild influenza-like illness. encephalitis, usually not severe, occurs in a small percentage of cases and may rarely feature seizures and coma. (from joynt, clinical neurology, 1996, ch26, pp9-10)