Bluetongue in Europe - the risk of animal import from restricted zones

摘要

Bluetongue (BT) is a vector-borne viral disease effecting ruminants caused by bluetongue virus (BTV), transmitted mainly by bites from midges of the genus Culicoides. Since the end of 20th century, BTV is endemic in several European countries and the disease is caused mainly by BTV-8 and BTV-4 infections. Bluetongue virus is characterized by high genetic diversity. To date, over 29 BTV serotypes have been documented, including recently discovered atypical serotypes BTV (25-27). The disease has a high economic impact as it causes economic losses due to animal mortality, reduced productivity and restrictions on the movement of animals. Several reports and numerous observations indicate the contribution of animal movements to the spread of BTV infections. Thus, bluetongue surveillance that includes testing of sentinel animals as well as virological testing of animals susceptible to BTV infection imported from restricted zones due to the presence of BTV is a key factor in maintaining a BT-free status.