Seroprevalence of bluetongue in sheep in Kohgiluyeh and Boyer-Ahmad province, Iran

Bluetongue (BT) is a viral disease of ruminants transmitted by Culicoides biting midges and has the ability to spread rapidly over large distances. The disease occurs almost worldwide between latitudes approximately 35˚ S and 50˚ N. Among the numerous diseases of ruminants, BT has gained considerable importance in recent years as one of the best examples of the effects of climate change on disease spread. Sheep are major livestock species in Iran, but studies of BT have not gained the priority compared to other diseases. Thus, the objective of this study was to describe the distribution and seroprevalence of bluetongue virus (BTV) infections in sheep in Kohgiluyeh and Boyer-Ahmad province of Iran, and to identify factors associated with the exposure of these sheep to BTV infection. Sera from 262 apparently healthy sheep were collected during the year 2011. The collected sera of the animals were screened with competitive enzyme like immunosorbent assay (c-ELISA). Two hundred and three (77.48%) out of 262 sera tested were positive to BTV antibodies. Statistically significant differences were found in the seroprevalence BT, between sex and age of sheep (p < 0.001). No statistically significant differences were observed in BTV seroprevalence among different seasons, nor among recently aborted and normally delivered.