Z. Broomand - Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
R. A. Jafari - Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran
M. Mayahi - Department of Clinical Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran

Newcastle disease virus (NDV), avian influenza virus (AIV), and infectious bronchitis virus (IBV) are the most prevalent viral pathogens in the Iranian poultry industry. This study aimed to reveal the presence of these viruses in the backyard chickens in Ahvaz, located in the Southwest of Iran. A total of ۱۰۰ chickens with respiratory signs and mortality were examined by taking the blood samples as well as tracheal and cloacal swabs. Most of the chickens had not received any vaccine. The blood samples were assessed for the antibodies against NDV and AIV by haemagglutination inhibition test, and against IBV by enzyme-linked immunosorbent assay. The swab samples were utilized for molecular detection using reverse transcription polymerase chain reaction (RT-PCR). Based on the results of the serologic test, ۷۷%, ۴۵%, and ۳۸.۴% of the birds were positive for NDV, AIV, and IBV, respectively. In the RT-PCR, ۹۵% of the birds were positive for one of the three viruses. The detection rates of NDV, AIV, and IBV were ۶۰%, ۳۴%, and ۵۵%, respectively. The coinfections of AIV/NDV, AIV/IBV, NDV/IBV, and AIV/NDV/ IBV were observed in ۱۳%, ۴%, ۲۳%, and ۷% of the sampled chickens, respectively. The results demonstrated that the Iranian backyard chickens were infected with NDV, AIV, and IBV. This could pose a threat to the commercial poultry; therefore, preventive measures need to be implemented in this regard.

Backyard chickens, Infectious bronchitis, Influenza, Newcastle disease