Pathotyping and genetic characterization of avian avulavirus-1 from domestic and wild waterfowl, geese and black swans in Pakistan, 2014 to 2017.

Twenty-nine avian avulavirus-1 viruses (AAvV-1s) from healthy domestic and wild ducks, geese and black swans collected in Pakistan between 2014-2017 have been pathotyped and genetically characterized. A phylogenetic analysis revealed that 21 of the isolates belonged to sub-genotype VIIi, whereas eight isolates were highly similar to vaccine-like viruses of genotype II. In addition to confirming the continued presence of sub-genotype VIIi AAvV-1s in Pakistan, this study identifies the probable spill-over of vaccine-like viruses from vaccinated poultry to wild and domestic waterfowl and, as such, has important implications for the control and management of Newcastle disease in Pakistan.