Bluetongue virus is ‘on-the-move’

Abstract

Bluetongue virus is ?on-the-move?. The distribution of this important arthropod-borne pathogen of sheep and cattle is expanding rapidly, particularly in Europe, where its emergence and spread during the past decade have had severe economic consequences. The movement of bluetongue virus into new temperate European habitats appears to have been driven, at least in part, by global warming. Record summer temperatures, warmer winters and changes in precipitation patterns are believed to have provided the conditions necessary for more northerly seasonal spread, over-wintering and adaptation of the virus to new insect vectors. The emergence of bluetongue disease in Europe since 1998 has resulted in the deaths of more than two million sheep. The economic impact in France alone in 2006-07 was estimated to have already exceeded $1.4 billion, mostly in lost trade. These events have significant implications for Australia, where freedom from disease and favourable terms of trade rest on a potentially fragile ecological balance between viruses, hosts and vectors.