Entomology

Entomology, meteorology, modelling, transmission, pathogenesis

Bluetongue (BT) is a disease of ruminants e.g. sheep, cattle, goats, deer. It is caused by bluetongue virus (BTV), of which there are 24 serotypes. Until recently the disease had been largely confined to certain regions within Africa, Asia, the Americas and Australia. Incursions of BTV into Europe, historically, only occurred as occasional, self-limiting infections in southern Iberia and some Greek islands. During the 1990s and since, climate-change has resulted in warmer weather in Europe, including milder winters, which has been conducive to the introduction and survival of infected midges from further south, resulting in the establishing of the disease in southern Europe (involving five serotypes. Subsequently, some indigenous European species of midge then spread the viruses much further.

Concurrently, in 2006, by means unknown, BTV serotype 8 was introduced into Europe for the first time. Moreover, it emerged in some countries of continental northern Europe, the first time that BTV has been known in those latitudes. It was spread to the UK by easterly winds carrying infected midges during August 2007.

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