Bluetongue in sheep: Question marks on bluetongue virus serotype 8 in Europe

Totally unexpected, bluetongue was diagnosed in northern Europe for the first time in August 2006 and the causal serotype was identified as bluetongue virus serotype 8, a serotype not previously being identified in Europe. This review gives a description of bluetongue, the history of the disease, the causal agent, and the development of vaccination. The review starts with a global overview of bluetongue and the bluetongue virus and vector and then, the European situation is emphasized from past incursions to the current outbreak of bluetongue virus serotype 8. Several studies are taking place in an attempt to answer at least some of the question marks on this recent outbreak in 2006 and its recurrence in 2007.