Determination of hemagglutinin and neuraminidase subtypes of avian influenza A viruses in urban pigeons by a new nested RT-PCR.

The prevalence of avian influenza viruses (AIVs) together with determination of hemagglutinin (HA) and neuraminidase (NA) subtypes were studied in urban pigeons using a new nested RT-PCR. Both oropharyngeal and cloacal swabs from birds were collected. Altogether, screening of all samples revealed that 12% of oropharyngeal and 20% of cloacal samples were positive for AIVs. However, samples from both the oropharynx and cloaca coming from one animal were positive in only 8% of pigeons. Four different HA and NA combinations H7N3, H7N6, H9N5, and H14N8 respectively, were identified using a new nested RT-PCR.