M. H. Fallah Mehrabadi - Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
N. Motamed - Department of Poultry Vaccines Research and Production, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Tehran, Iran
A. Ghalyanchilangeroudi - Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
F. Tehrani - Iranian Veterinary Organization, Tehran, Iran
A. Borhani Kia - Private Veterinary Clinic, Tehran, Iran

The present study aimed to determine the seroprevalence of H۹N۲ influenza in broiler farms at the time of slaughter in Iran. A total of ۷۴۷ birds were sampled from ۷۴ Farms in ۱۳ provinces within ۲۰۱۳-۲۰۱۶. The obtained sera were investigated using the hemagglutination inhibition (HI) test. Out of ۷۴ sampled farms and ۷۴۷ birds, ۵۷ farms (۷۷%) and ۴۴۵ (۵۹.۵۷%) birds were reported to be seropositive. In ۲۰۱۳, ۱۰ farms and ۱۱۰ birds were sampled out of which three farms (۲۹.۶%) and ۲۹ birds (۳۰%) were seropositive. In ۲۰۱۴, ۲۴ farms and ۲۲۰ birds were sampled out of which ۲۲ farms (۹۱.۶%) and ۲۲۰ birds (۸۶.۶%) were positive in six provinces. In ۲۰۱۵, ۳۰ farms and ۲۷۸ birds were sampled out of which ۵ farms (۱۶%) and۱۳۴ birds (۴۸.۲%) were positive in four provinces. Finally, in ۲۰۱۶, ۷ farms (۷۰%) out of ۱۰ sampled farms and ۶۲ birds (۵۹%) out of ۱۰۵ sampled birds were positive for H۹N۲ in eight provinces. The mean titer of units in ۲۰۱۳ was statistically lower, as compared to that in ۲۰۱۴ (p <۰.۰۱). In addition, the proportion of positive serum units in ۲۰۱۳ was statistically lower, as compared to that in ۲۰۱۴ (p <۰.۰۰۱). In general, the prevalence of H۹N۲ was high indicating the continuous circulation of the virus in Iran. Given the importance and impact of this virus on the poultry industry, people’s livelihood, and public health, more epidemiological studies are needed to evaluate the effectiveness of the adopted measures and methods in controlling the H۹N۲ virus.

Avian Influenza H۹N۲, broiler farms, Abattoirs, Iran, Seroprevalence