Seroprevalence of Newcastle disease virus and avian influenza virus in poultry and captive wild birds in poultry- dense regions of Pakistan

Newcastle disease virus (NDV) and avian influenza virus (AIV) are causing contagious diseases in chickens and wild birds worldwide; however, there is a paucity of information on the current status of seropositivity of Newcastle and avian influenza diseases in chickens and wild birds of Pakistan. Therefore, the present study aimed to investigate the serological evidence of both diseases in commercial poultry (broiler, layer chickens), backyard poultry, and captive wild birds in poultry-dense regions of Punjab, Pakistan. Enzyme-linked immunosorbent (ELISA) and haemagglutination inhibition (HI) assays were performed for the determination of antibodies against NDV and AIV and their genotyping and subtyping, respectively. Overall, 47.5% and 67.4% seroprevalence of NDV and AIV, respectively, was observed in both poultry and wild birds. Based on bird's category, layer chickens had the highest seroprevalence of NDV (60.8%, 95% CI: 52.95-68.22, OR: 0.71) followed by backyard poultry (56.8%, 95% CI: 47.92-65.32, OR: 0.82), broilers (52.7%, 95% CI: 46.84-58.64), pigeons (41.3%, 95% CI: 30.5352.81, OR: 1.59), peafowls (26.1%, 95% CI: 11.09-48.69, OR: 3.16), ducks (23.8%, 95% CI: 12.59-39.8, OR: 3.57), turkeys (16.7%, 95% CI: 4.41-42.27, OR: 5.58), parrots (14.3%, 95% CI: 2.52-43.85, OR: 6.70) and quails (2.3%, 95% CI: 0.2-13.51, OR: 4.8). Comparatively, backyard chickens had the highest seroprevalence of AIV (78.8%, 95% CI: 70.64-85.22, OR: 0.63) followed by ducks (73.8%, 95% CI: 57.68-85.6, OR: 0.83), layers (73.5%, 95% CI: 65.98-79.89, OR: 0.84), pigeons (72.5%, 95% CI: 61.2-81.61, OR: 0.89), broilers (70.1%, 95% CI: 64.44-75.29), turkeys (55.5%, 95% CI: 31.35-77.6, OR: 1.87), peafowls (47.8%, 95% CI: 27.42-68.9, OR: 2.56) and parrots (42.8%, 95% CI: 18.8-70.3, OR: 3.1). Overall, 40.1%, 34.2%, 31.3%, and 25.1% sera were positive for H9 AIV, G-VII NDV, H7 AIV, and G-VI NDV, respectively. The current study revealed a widespread exposure to NDV and AIV in poultry and captive wild birds. Therefore, it is crucial to include captive wild birds in NDV and AIV surveillance programs to further strengthen disease control measures, particularly in endemic regions.