Assessment of influenza A virus infection in horses of West Azerbaijan province using competitive ELISA

Equine influenza is an extremely contagious respiratory disease of horses caused by the influenza A virus. The present study aimed to determine the prevalence of influenza A virus infection in horses of West Azerbaijan Province, north-west Iran. A total of ۱۸۴ horse serum samples were collected from four localities and tested by competitive enzyme-linked immunosorbent assay to detect antibodies against the nucleoprotein of the influenza A virus. Data were analyzed for the effect of gender, age, and location on seropositivity by the chi-square, Fisher's exact, and logistic regression tests. The prevalence rate was estimated to be ۵.۴% (۹۵% CI: ۲.۱۴–۸.۶۶%). Based on regression analysis, the odds of infection based on age in years was ۰.۵۸۱ (۹۵% CI: ۰.۱۷۶–۱.۹۱۶) (P > ۰.۰۵), and age explained -۰.۵۴۴% of the variations in infection. The relative frequency of infection in male and female horses was ۲.۶ and ۷.۴%, respectively (P > ۰.۰۵), and the odds of infection in females compared with male horses was ۲.۷۲ (۹۵% CI: ۰.۵۳۶–۱۳.۷۹۴). Sex explained ۱.۰۰۱% of infection variations. The prevalence rate in Sardasht, Urmia, Khoy, and Chaldoran was ۴%, ۴.۸%, ۶.۲%, and ۶.۸%, respectively. A non-significant increase in prevalence was observed from the south to the north of the province (P > ۰.۰۵). Geographical location explained ۰.۰۴۷% of infection variations. The final summary of results indicates that exposure to the influenza A virus is very low in horses of the studied regions.

Keywords:

ELISA , Horse , influenza virus , West Azerbaijan