Preliminary observations on the epidemiology of bovine ephemeral fever in China.

Bovine ephemeral fever (BEF) is a viral disease of cattle and water buffalo recognised for the first time in China in 1955. The disease has been endemic in south China with 13 epidemics since 1955, seven epidemics reaching central China and one extending into north-east China (40 degrees N). The outbreaks have been seasonal with all occurring in the warmer summer/autumn months of June to October when possible insect vectors are active. Reports of clinical disease were confirmed as BEF by the detection of virus-neutralising antibody. The economic impact of the disease includes loss of milk production, late-term abortions and the loss of draught animal power.