Serological survey for avian metapneumovirus in commercial chickens from different climatic zones in Nigeria

Avian metapneumovirus (aMPV) is an important poultry pathogen causing an acute highly contagious upper respiratory tract infection in chickens, and could result in swollen head syndrome. The disease causes significant economic losses in turkey and chicken flocks; however, its existence in the Nigerian poultry industry is not well defined. Also, the influence of weather on the prevalence of the disease is unknown. This study was therefore carried out to determine the prevalence of Avian Metapneumovirus in chicken flocks from different climatic zones of Nigeria during both dry and wet seasons. Eighty commercial chickens (growers and adults) including layer and broiler flock from randomly selected local government areas from each of Sokoto, Plateau and Oyo States of Nigeria, were bled via jugular venipuncture for detection and titration of aMPV antibodies in serum “(n=240 serum samples each from both dry and wet season)”. Assay was carried out using a commercial enzyme-linked immunosorbent assay kit (ID Screen®, Rue Louis Pasteur-Grabels-France) which was able to determine antibodies against A, B, C and D subtypes of the virus.  Out of a total of 480 samples collected, 287 (59.8%) were positive for aMPV antibodies. During the dry season, prevalence was 100, 56.2 and 48.8% in Plateau, Sokoto and Oyo States, respectively, while it was 52.5, 65.2 and 36.2%, respectively during the wet season. Commercial chickens screened during the dry season (68.3%) and mean aMPV antibody titer of 2990.95 had significantly (α<0.001) higher seroprevalence of aMPV antibody compared to those screened in the wet season (51.2%) and mean aMPV antibody titer of 572.98. This study therefore shows that aMPV circulates more in the dry season in the studied areas of Nigeria. Key words: ELISA, avian metapneumovirus (aMPV), antibodies, weather conditions, seroprevalence, commercial chickens.