Active Surveillance and Genetic Characterization of Prevalent Velogenic Newcastle Disease and Highly Pathogenic Avian Influenza H5N8 Viruses Among Migratory Wild Birds in Southern Egypt During 2015-2018.

A total of 1007 samples (910 fecal droplets and 97 cloacal swabs) were collected from 14 species of migratory wild birds in most wetlands during 3 successive migration seasons from September to March (2015-2018) in Southern Egypt. The samples were propagated in embryonated chicken eggs and positive allantoic fluids by hemagglutination test were tested for Newcastle disease virus (NDV) and avian influenza virus (AIV) prevalence using RT-PCR and specific primers targeting the NDV fusion (F) and AIV matrix genes. Further subtyping of the AIV hemagglutinin (HA) and neuraminidase (NA) was conducted, and representative isolates were selected and sequenced for full F gene of NDVs and HA and NA genes of the AIV.