Bluetongue: A Review and Global Overview of the Only OIE List a Disease that is Endemic in North America (13-Nov-2004)

Introduction Bluetongue virus (BTV) is the etiologic agent of bluetongue (BT), a non-contagious, insect-transmitted disease of sheep and some species of wild ruminants [4,19,24,32]. BT disease was first recognized and comprehensively described in southern Africa [32], and BTV has subsequently been isolated from ruminants and/or vector insects from all continents except Antarctica [16]. Because BTV infection of ruminants is not contagious, the global distribution of BTV coincides with the distribution of competent Culicoides insect vectors. Although BTV infection of domestic and wild ruminants occurs throughout much of the world with minimal occurrence of disease, BT is just one of 16 diseases classified in List A by the Office International des Epizooties (OIE), which is the world organization for animal health. As a direct consequence of its inclusion in the OIE List A, BT continues to impact the global trade of ruminants and their germplasm [2]. Furthermore, BTV recently emerged throughout much of the Mediterranean Basin to precipitate the largest and most economically devastating epidemic of BT ever described in Europe, and the virus currently is endemic in substantial portions of Italy, Greece, the Balkans, and adjacent countries. The incursion of BTV into southern Europe has had a devastating impact on livestock production in the region (especially in Italy) because of severe disease and remarkably high mortality in sheep, and restrictions of the movement of domestic livestock [5]. To address the growing international impact of BT, the OIE and the European Union recently sponsored the Third International Symposium on Bluetongue that was held in October, 2003, in Taormina, Sicily (www.bluetonguesymposium.it/index.htm).