Epidemiology of bluetongue and epizootic haemorrhagic disease in wildlife: surveillance methods.

Bluetongue (BT) and epizootic haemorrhagic disease (EHD) are the most important viral diseases that affect wild ungulates, especially white-tailed deer, in the United States of America (USA). For this reason, considerable surveillance has been conducted. Surveillance has relied upon standard serological and virus detection methods, and both passive and active surveillance strategies have been employed effectively. These efforts have led to an improved understanding of the epidemiology of these diseases in wild ungulate populations, specifically the recognition and understanding of geographically predictable disease patterns ranging from enzootic stability to sporadic epizootics. The utilisation of wildlife in BT and EHD surveillance may be unique to the USA where these diseases are important to both wildlife and livestock interests.