Bluetongue Virus (BTV)

This is a so-called orbivirus within the family Reoviridae, which has a size of 70 nm and possesses double-stranded RNA with about 10–12 genome segments. BTV is transmitted during the bite of the very tiny females of the insect family Ceratopogonidae (midges). The most important symptom of the disease in ruminants is hemorrhages in the mouth (i.e., leading to a blue tongue), on the surface of the udder and between the claws introducing painful and stiff movements of cattle. The disease which is common but mostly symptomless in South African game animals is based on any 24 different serotypes of this virus. Although the disease is not contagious, it led since its first arrival (1998) in South Europe to the death of more than one million sheep and also many thousands of specimens of cattle.

Since 2006 whole Europe was hit by two virus epidemics in ruminants, which followed each other: bluetongue disease (BTV) in the years 2006–2009 and occurrence of the so-called Schmallenberg virus...