Serological survey of avian influenza virus among indigenous chicken in Ibarapa region of Oyo State, Nigeria

Abstract

Avian influenza, a highly contagious viral disease caused by influenza A viruses of the family Orthomyxoviridae, presents significant global economic and public health challenges. Studies have emphasised the importance of commercial chickens in the epidemiology of avian influenza virus (AIV) in sub-Saharan Africa. Still, there is limited data on AIV prevalence among indigenous chickens. This study aimed to assess the seroprevalence of AIV among indigenous household chickens in the Ibarapa region of Oyo State, Nigeria. Blood samples were randomly collected from 255 healthy indigenous chickens over four months noting their location, age and sex. Serum samples were harvested and stored at -20°C before conducting a serological assay. A competitive enzyme-linked immunosorbent assay (ELISA) detected avian influenza virus nucleoprotein antibodies. The Chi-square test was applied to determine associations between location, age, sex and seroprevalence of AIV with significance set at p≤0.05. The overall seroprevalence of AIV was 18.8%, with a statistically significant higher seropositivity rate (23.15%) observed in Ibarapa Central (χ2 = 12.95, p-value = 0.02). Higher seroprevalence of AIV was observed in adult chickens (20.2%) and female birds (21%) However, no statistical significance was observed with age, sex and seropositivity to AIV (p>0.05). This study provides evidence of AIV exposure among indigenous household chickens in the Ibarapa region and emphasizes the need for targeted surveillance and biosecurity measures in high-risk areas. Molecular characterization is also advised to better understand the role of indigenous chickens in the epidemiology of AIV.