Seroprevalence of H5, H7 and H9 subtypes of avian influenza viruses in rural domestic poultry of Ardabil province, Iran

Backyard poultry can cause spread the virus to industrial poultry as reservoirs and vectors. The aim of this study was to survey seroprevalence of H5, H7 and H9 subtypes of avian influenza virus in rural domestic poultry of Ardabil province, northwest of Iran. In this study, 943 blood serum samples were randomly collected from backyard poultry of 40 villages. The hemagglutination inhibition (HI) test was performed on the serum samples according to OIE protocol to detect H5, H7 and H9 subtypes of influenza virus. In this study antigens H5N2 and H7N1 were used for H5 and H7 ,respectively. Suspicious samples on the first test were examined with the second antigens, namely H5N1 and H7N7. Moreover, sera with titers ≥4 (i.e. log2) were considered positive. Out of 40 sampled villages, 31 villages (77.5%) and out of 943 birds sampled, 327 birds (34.7%) were positive for H9N2 subtype of influenza virus. All the examined sera were negative for H5N1, H5N2, H7N1 and H7N7 subtypes of influenza virus. The results of this study showed that seroprevalence of H9N2 influenza virus and its circulation in rural domestic poultry of Ardabil province. The implementation of disease prevention and control measures such as compliance biosecurity principles, vaccination and continuous monitoring of circulating viruses in rural poultry to reduce the contamination of domestic poultry and prevent the spread of the virus to industrial poultry are necessary.