Fowl adenovirus is responsible for various diseases, such as hepatitis hydropericardium syndrome (HHS), inclusion body hepatitis (IBH), and gizzard erosion. HHS, caused by fowl adenovirus serotype 4 (FAdV-4), is a highly pathogenic viral disease that affects 3 to 5-week-old chickens and causes a high mortality rate and significant economic losses. In Iran, HHS has been reported in march 2021 for the first time in a 15-day-old broiler flock. Detection of fowl adenovirus can be performed by various serological methods, including enzyme-linked immunosorbent assay (ELISA), virus neutralization (VN), agar gel immunodiffusion (AGI), counterimmunoelectrophoresis, fluorescent antibody techniques, and immunoperoxidase assays, as well as molecular methods such as polymerase chain reaction and real-time polymerase chain reaction. In the current study, we analyzed the level of specific antibodies against the FAdV-4 serotype in 44 blood samples of unvaccinated backyard chickens from Golestan province in northern Iran using ELISA assay. According to the ELISA results, the overall prevalence was 22.72%, and the highest was found in Saad Abad village, which had 66.66%. The results also show that the highest antibody titer was found in the Haji Balkhan group, with 1679.91, and the lowest in the Amir Abad group, with 3.22. The other titers were mostly between 100 and 300. This study is the first serological investigation of FAdV-4 in backyard chickens of Iran. While the virus can only be detected by molecular techniques such as PCR, these discoveries may offer new perspectives on the spread of the virus in the northern region of Iran and help develop innovative vaccination strategies.
Hosseini et al. (Sun,) studied this question.