Molecular Detection and Histopathological Effect of Infectious Bronchitis Virus Circulating in Vaccinated Broiler Flocks in Basrah, Iraq

Aims: Infectious bronchitis is a disease that has spread all over the world and is very difficult to control because of the multiple serotypes and variant strains. Rapid detection of Infectious Bronchitis Virus is beneficial for control measures and scientific research. The aim of the current study was to detect Infectious Bronchitis Virus in Basrah Province using molecular techniques that target the 5’ untranslated region gene of Infectious Bronchitis Virus, which is less variable than other genes, and find the histopathological changes caused by these types of viruses. Materials Methods: About 80 clinical tissue samples (kidney and trachea) were collected from broiler chicks with clinical findings related to Infectious Bronchitis Virus. Then the samples were subjected to real-time PCR and histopathological techniques. Findings: The molecular part of the study explained infectious bronchitis in all studied farms. Positive samples to infectious bronchitis were detected with real-time PCR. The histopathological changes included excessive vacuolation mostly in subcapsular renal tubules, aggregation of inflammatory cells in subcapsular renal tubules, hemorrhage and inflammatory cells in mucosal and submucosal layers of the trachea and discharge in the tracheal lumen. Conclusion: Infectious Bronchitis Virus is still circulating with devastating effects on the poultry industry in Basrah Province, and this might be due to the lack of awareness among the owners of the farms in matters related to biosecurity and vaccination program.