Cluster poultry farming, the bane of highly pathogenic avian influenza spread in Lagos State Nigeria.

There have been no recorded epidemics of highly pathogenic avian influenza since September, 2016 in Lagos State, and since February 2019 in Nigeria. A resurgence occurred on the 25 th of May, 2021. This study gives focused case report of fresh outbreaks of HPAI in Lagos state, south-western Nigeria. Investigation revealed that there were seventy four (74) epidemiologically linked outbreaks in six (6) locations: - Aiyedoto and Ojo military cantonment (Amuwo-odofin LGA), Ajah (Eti-osa LGA), Ago palace Okota (Isolo LGA), Oke-Oshodi (Epe LGA) and Badagry (Badagry LGA). Intensively managed, adult laying birds kept in clusters of less than 10 meters apart in Aiyedoto poultry farm settlement were predominantly affected. Disease prevalence was 15.7%. Incidence rate of infection was 0.2 per hundred bird-days at risk, associated mortality rate was 67 per x103 birds. Real time PCR revealed HPAI H5N1. Stamping out of the entire bird population in affected areas was done. Barely a year after the 2021 outbreaks were curtailed, on the 16th of October, 2022 another outbreak was reported from Agricultural Youth Empowerment Scheme (AGRIC YES) poultry farm settlement. The outbreak at this time was reported in 5 locations: - Aiyedoto and Ojo military cantonment (Amuwo-odofin LGA), Araga (Epe LGA), Awoyaya Ibeju and Lekki (Ibeju-Lekki LGA). In all there were 16 outbreaks. Policy review regarding siting and spacing of poultry farm premises in addition to inter- and intra-state movement of birds is inevitable to control disease spread and reduce associated public health risk.