Retrospective Study of Highly Pathogenic Avian Influenza Outbreaks from 2015 to 2022 in Rivers State, Nigeria

Abstract

Highly pathogenic avian influenza (HPAI) constitutes one of the major constraints in the development of the poultry industry, and sporadic outbreaks are still being reported in Nigeria. It is zoonotic, with several reports of human cases. The aim of this study was to determine the trend and distribution of HPAI outbreaks from 2015 to 2022 in Rivers State, Nigeria. Eight-year retrospective study was conducted by reviewing the Avian influenza (AI) line list and case reports of confirmed outbreaks of HPAI in Rivers State from the AI desk office. Data were cleaned, analyzed using descriptive statistics, and presented using tables and figures as appropriate. The outcomes showed that a total of 67 HPAI cases were reported in Rivers State from 2015 to 2022, with the highest (64.2%) reported in 2015 and lowest (1.5%) in 2022. Layers were majorly affected. The HPAI cases were reported across 6 Local Government Areas (LGAs), with the highest (71.6% cases) reported in Obio-Akpor and the lowest (1.5%) in Oyigbo and Ogba-Egbema-Ndoni LGAs. Based on the distribution according to LGA and year, HPAI cases were reported in 5 LGAs (Port Harcourt, Obio-Akpor, Ikwerre, Oyigbo and Ogba-Egbema-Ndoni) in 2015, 2 LGAs (Obio-Akpor and Ikwerre) in 2016, 4 LGAs (Port Harcourt, Obio-Akpor, Ikwerre and Okrika) in 2021, and 1 LGA (Obio-Akpor) in 2022. The 2015 – 2022 outbreaks of HPAI in Rivers State were reported in six out of the 23 LGAs across Rivers State. Obio-Akpor LGA accounted for the highest-burden of HPAI in the State. There was no report of HPAI from 2017 to 2022 across the State. Intensive surveillance for AI and public awareness on prevention and control across Rivers State is, therefore, recommended with support and motivation from the government.