Seasonal effects on the prevalence of bluetongue in small ruminants in west Azarbaijan, Iran

BACK GROUND: Bluetongue virus (BTV) is recognized to infect ruminants all around the world, and its prevalence mainly depends on the BTV situation, vectors distribution, weather patterns and susceptibility of the host. Objectives: The purpose of this study was to draw a correlation between the prevalence of BTV antibodies and climate changes in Iranian Azerbaijan Province. METHODS: Sera samples were collected from sheep, in a period of a year between 2008- 2009. The seroprevalance of Bluetongue antibodies were evaluated using an Enzyme-linked Immunosorbent Assay, considering monthly weather changes in the Province, recorded by the Iran Meteorological Organization. RESULTS: The infection rate was found to be 55.9% and there was a peak BTV prevalence of at 81% (p<0.001). The Pearson correlation coefficient ranges were found to be between 0.36 and 0.005. CONCLUSIONS: The vector distribution is based on climatic changes and environmental conditions. It was concluded that the phenotypic expression of the BTV gene may be influenced by the weather.