Population Dynamics and Disease Ecology of Avian Influenza at Poultry-Wild Bird Interfaces in Nigeria

This study investigates the population dynamics and disease ecology of avian influenza at poultry-wild bird interfaces in Nigeria, developing an original eco-epidemiological framework for understanding AIV persistence and emergence risk in West Africa. Highly pathogenic avian influenza H5N1 and H5N8 have caused repeated devastating outbreaks in Nigerian poultry since 2006, with the epidemiological mechanisms linking wild bird reservoirs to poultry transmission poorly understood in the Nigerian context. This study conducts a multi-year surveillance programme across key wild bird migration and congregation habitats in Nigeria's major poultry production zones, collecting oropharyngeal and cloacal samples from 4,800 migratory and resident wild birds across 24 sampling sites in Anambra, Kano, Lagos, and Borno States. AIV is characterised by RT-PCR, hemagglutinin and neuraminidase sequencing, and whole genome sequencing of positive isolates. Wild bird population dynamics are monitored through systematic point count surveys and GPS telemetry on 120 tagged birds of key species. Epidemiological modelling links wild bird AIV prevalence and movement data to poultry outbreak records from 2015 to 2023. Spatiotemporal risk mapping identifies poultry farms with highest wild bird interface exposure. Findings reveal that Afro-Palearctic migratory ducks and wading birds arriving in October to November are the primary HPAI introduction pathway, with spillover risk modulated by proximity to wetland habitats and live bird market activity. The study contributes an original Nigerian AIV eco-epidemiological model and recommends risk-stratified biosecurity requirements for poultry farms at highest wild bird interface risk.

Keywords: avian influenza, eco-epidemiology, wild birds, poultry, Nigeria.