Serological Survey of Avian Metapneumovirus Infection in Broiler Breeder Chicken Farms in Tamil Nadu

Avian metapneumovirus (aMPV) is an important poultry pathogen causing an acute highly contagious upper respiratory tract infection in chickens leading to swollen head syndrome. The disease can cause significant economic losses in turkey and chicken flocks, particularly when exacerbated by secondary pathogens. The purpose of this study was to determine the prevalence of avian metapneumovirus antibodies in broiler breeder flocks in Tamil Nadu, India. Twenty numbers of broiler breeder farms located in Tirupur district of Tamil Nadu were selected randomly and blood samples were collected. A total of 485 blood samples were collected from 20 broiler breeder chicken flocks (aged between 4 and 72 weeks). The serum samples were tested for the presence of antibodies against avian metapneumovirus by using a commercial enzyme-linked immunosorbent assay kit (IDEXX APV Ab test, Liebefeld-Bern, Switzerland) which was able to determine antibodies against A, B and C subtypes of avian metapneumovirus. Out of 485 serum samples, 165 (34.02%) were positive to avian metapneumovirus antibodies, which represented 14 of 20 (70%) examined broiler breeder flocks. All the chickens had not been vaccinated against avian metapneumovirus in India and these results indicate that commercial poultry birds are exposed to this important poultry pathogen. This is the first report of serologic evidence of AMPV in India. Its prevalence has to be investigated in other parts of India. Future work may and should include the use of molecular methods and isolation of the virus. Isolation of avian metapneumovirus will allow the possibility of controlling the disease.