In the Old World, African horse sickness (AHS) and equine encephalosis are transmitted to equids by Culicoides midges. AHS has a case-fatality-rate of 95% in horses. Though endemic to sub-Saharan Africa, AHS virus is able to incur northwards and to disseminate widely within Mediterranean countries. For example, >1,000 equines died during the AHS-epidemics affecting Spain, Portugal and Morocco (1987-1991). The virus was isolated not only from Culicoides imicola, but also from species endemic to Europe: C.