Avian Influenza (H9N2 Subtype) in Broiler Farms in Iran: A cross- sectional study

Document Type: Original Articles


1 Department of Poultry Diseases, Razi Vaccine and Serum Research Institute, Agricultural Research,Education and Extension Organization (AREEO), Tehran.Iran

2 Razi Vaccine and Serum Research Institute

3 Associated Professor of Department of Microbiology and Immunology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

4 Iran Veterinary Organization, Tahran, Iran.


The aim of this study was to determine the sero-prevalence of H9N2 influenza in broiler farms at the time of slaughter in Iran. Methods: A total of 747 birds from 74 Farms in 13 provinces were sampled from 2013 to 2016. Sera were investigated using heamagglutination inhibition test (HI) test. Results: out of the 74 farms Fifthy seven (77%) and 445 birds out of the 747 sampled birds (59.57% ) were sero- positive. In 2013, three farms (29.6%) out of 10 sampled farms and 29 birds (30%) out of 110 sampled birds, In 2014, 22 farms (91.6%) out of 24 sampled farms and 220 birds (86.6%) out of 254 sampled in 6 provinces, In 2015, 5 farms (16%) out of 30 sampled farms and134 birds (48.2%) out of 278 sampled birds in 4 provinces and finally In 2016, 7 farms (70%)out of 10 sampled farms and 62 birds (59%) out of 105 sampled birds in 8 provinces were positive for H9N2. The mean titer of units in 2013 was statistically lower than that in 2014 (P <0.01). The proportion of positive serum units in 2013 was statistically lower than that in 2014 (<0.001).Conclusions: Overall the prevalence of H9N2 was high that indicate the continuous circulation of the virus in Iran. Considering the importance and impact of the virus on poultry industry and pepole Livelihood as well as public health there is a need for more epidemiological studies to evaluate the effectiveness of the measures and methods taken to H9N2 control.