Isolation and Characterisation of Newcastle Disease Virus from Backyard Poultry in Borno State, North East Nigeria

Newcastle Disease Virus (NDV) is a highly contagious avian paramyxovirus responsible for severe economic losses in Nigeria's poultry industry, with backyard flocks in rural North East communities particularly vulnerable due to limited veterinary oversight. This study aims to isolate and characterise NDV strains from clinically affected backyard poultry in Borno State, North East Nigeria. Cloacal and tracheal swabs will be collected from 200 birds exhibiting respiratory and neurological signs across five local government areas in Borno State. Virus isolation will be performed in specific-pathogen-free embryonated eggs, and positive samples will be confirmed by haemagglutination and haemagglutination inhibition tests. Molecular characterisation will be carried out using RT-PCR targeting the F gene, followed by phylogenetic analysis to determine pathotype. Epidemiological data on flock management, vaccination status, and bird movement patterns will be collected concurrently. Studies from neighbouring states indicate a predominance of genotype V and VII strains in unvaccinated flocks, associated with velogenic pathotypes causing high mortality. Characterisation of circulating strains in Borno State will provide critical data for updating regional vaccination programmes and informing the Federal Department of Veterinary and Pest Control Services. This study supports agricultural biosecurity objectives in conflict-affected northern Nigeria, where poultry represents a critical livelihood resource for rural households. Keywords: Newcastle Disease Virus, backyard poultry, Borno State, isolation, molecular characterisation