Clinicopathological characterization of experimental infection in chickens with sub-genotype VIIi Newcastle disease virus isolated from peafowl.

Newcastle disease (ND) is an economically important viral disease distressing poultry industry across the globe. Herein, we report the clinicopathology of sub-genotype VIIi Newcastle disease virus (NDV) isolated from peafowl in chickens. The virus isolate produced systemic infection with prominent tropism in visceral organs in chicken, confirmed on the basis of gross and microscopic lesions, and immunohistochemistry findings. The experimentally infected chickens exhibited 100% mortality with severe hemorrhagic lesions in the proventriculus and intestine, especially marked lymphocytolysis in spleen and bursa. The virus could be re-isolated from the cloacal swabs of infected chickens during 4th to 6th dpi (on 6th dpi all birds died), and all were tested positive in conventional RT-PCR. This is the first report on clinicopathology of NDV isolated from peafowl and/or sub-genotype VIIi NDV in experimentally infected chickens. Explorative epidemiological and molecular studies are suggested to screen wild peafowls and poultry flocks of the country for establishing the occurrence of this sub-genotype and opting for appropriate prevention and control strategies.