M. H. Fallah Mehrabadi - Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Karaj, Iran
A. Bahonar - Department of Food Hygiene and Quality Control, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
K. Mirzaei - Department of Health and Management of Poultry Diseases, Qazvin Veterinary Organization, Qazvin, Iran
A. Ghalyanchi Langeroudi - Department of Microbiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
S. A. Ghafouri - Department of Health and Management of Poultry Diseases, Iranian Veterinary Organization. Tehran, Iran
F. Tehrani - Department of Health and Management of Poultry Diseases, Iranian Veterinary Organization. Tehran, Iran
A. Hashemi - Department of Health and Management of Poultry Diseases, Iranian Veterinary Organization. Tehran, Iran

The aim of this study was to determine the seroprevalence of avian influenza H۹N۲ subtype in the industrial ostrich farms and its geographical distribution. This cross-sectional study was conducted from January to June ۲۰۱۵. A total of ۴۰ farms were selected from different provinces of Iran, from each of which ۱۱ ostriches (n=۴۴۰) were sampled. The sera samples were examined using ۴ hemagglutination units of H۹N۲ antigens. A frequency distribution was used to describe the responses to the survey questions. The mean titers between provinces were compared using one-way analysis of variance. According to the results, ۲۱ (۴۷.۵%) out of ۴۰ farms and ۱۰۸ (۲۴.۵%) out of ۴۴۰ ostriches tested positive in the HI-H۹N۲ test. There were statistically significant differences between the mean titers of samples in different provinces (P<۰.۰۰۱). The current study was conducted on unvaccinated ostriches. The results showed that H۹N۲ had a high seroprevalence at both farm and bird levels. The findings of this study can be for the further investigation of infection in ostrich farms in order to consider this species in the surveillance programs of the Iranian Veterinary Organization. The detection and isolation of viruses and epidemiological investigation are necessary for the persistent use of H۹N۲ vaccines in some ostrich farms.

Ostrich, Seroprevalence, H۹N۲, Avian Influenza, Iran