Identification of bovine ephemeral fever (BEF) outbreak in a large dairy farm in Varamin, Iran

Bovine Ephemeral Fever (BEF) flared up in a dairy farm with 2097 animals. The disease started in September, 2006, with daily means of environmental temperature (ET) and relative humidity (RH) of 23.8 ºC and 37%, respectively, and ended after 48 days with ET and RH of 16.2 ºC and 68%, respectively. In this outbreak, the age of affected animals was above 10 months and the morbidity rate was 13.07%. Clinical signs included fever, hyperpnoea, mouth breathing, subcutaneous emphysema and death. Histologically, there were vasculitis,hyperemia; hemorrhage and edema in soft tissues and rupture of alveolar walls. Both Culex and Colicoides spp. were captured as vectors. Bovine Ephemeral Fever virus genome was detected in blood samples by RT-PCR and the CPE was shown by blood sample culture.