Molecular detection of fowl adenovirus 7 from slaughtered broiler chickens in Iran: the first report

Background: Fowl adenoviruses (FAdVs) are responsible for a variety of clinical symptoms, with an increasing significance in the poultry industry throughout the world. Typical diseases caused by FAdVs include inclusion body hepatitis (IBH), hepatitishydropericardium syndrome (HHS), gizzard erosion (GE), respiratory disease, and hemorrhage in muscles and organs. Aims: During 2020, broiler chickens from the north of Iran showed ecchymotic and petechial hemorrhages in thigh and breast muscles at the slaughterhouse. Hemorrhages were observed in 10% to 60% (with an average of 2030%) of chicks per flock. To find out the etiology of these lesions, the present study was conducted. Methods: Different environmental factors were investigated, and FAdV, infectious bursal disease virus (IBDV), and chicken infectious anemia virus (CIAV) were detected using molecular assays. Results: Among the viruses tested, FAdV was detected by polymerase chain reaction (PCR), and sequence analysis clustered the virus into species E, serotype 7. Conclusion: This is the first report on FAdV7 existence among poultry in Iran. Effective screening of the chicks at slaughtering age should be performed from the whole country.