Repeated isolation of virulent Newcastle disease viruses in poultry and captive non-poultry avian species in Pakistan from 2011 to 2016.

Virulent viruses of the panzootic Avian avulavirus 1 (AAvV-1) of sub-genotype VIIi were repeatedly isolated (2011-2016) from commercial chickens and from multiple non-poultry avian species in Pakistan. These findings provide evidence for the existence of epidemiological links between Newcastle disease outbreaks in commercial poultry and infections with virulent AAvV-1 strains in other avian species kept in proximity to poultry. Our results suggest that the endemicity of Newcastle disease in Pakistan involves multiple hosts and environments.