Equine encephalosis virus

The Equine encephalosis virus (EEV) is a virus of the Orbivirus genus, and a member of the Reoviridae family, related to the African Horse Sickness Virus (AHSV) and the Blue Tongue Virus (BTV).

First described in South Africa over a hundred years ago by Arnold Theiler, EEV is the causative agent of Equine Encephalosis (EE), an arthropod-borne disease transmitted by the Culicoides spp. midges affecting all equids. Since then the disease has become both widespread and prevalent, taking on epidemic proportions in certain parts of the country. Serological studies estimated a presence of anti-EEV antibodies in over 75% of all South African horses.