Infection of the vectors and bluetongue epidemiology in Europe.

The author describes some of the factors controlling the infection and transmission of bluetongue (BT) virus (BTV) by vector species of Culicoides. Also outlined are certain important features of the recent BT epizootic in the Mediterranean Basin, concentrating on those aspects involving vector transmission and overwintering of the virus. The regions affected by the outbreaks and the BTV serotypes involved are set out, the distribution of the major vector, C. imicola is described and the impact of novel vector species of Culicoides and a possible overwintering mechanism for the virus in Europe, are discussed.