Serological Evidence of Avian Metapneumovirus Infection in Layer Chicken Farms of Madhya Pradesh, India

Background: Avian metapneumovirus (aMPV) is an important viral agent in chicken and turkey production industry and is most commonly associated with acute upper respiratory tract infection and swollen head syndrome. The disease is of significant economic concern as it is highly contagious and can lead to production losses in chicken and turkey flocks, especially when associated with secondary bacterial pathogens. Methods: Herein, we have performed a survey on layer farms in selected areas of Madhya Pradesh State, India to ascertain the aMPV status in laying birds, choanal cleft swabs and sera samples were collected for ELISA and RT-PCR assay. A total of 263 sera and 169 choanal cleft swabs from five districts of Madhya Pradesh State (Indore, Bhopal, Sagar, Guna and Bhind) from layer birds of age group 20-72 weeks were screened for aMPV antibodies and for genome. Result: Out of these Indore had maximum sero-postivity (73.33%), followed by Sagar (5.00%) and Bhopal (4.08%), respectively. Other two districts did not show any seropostivity against aMPV. RT-PCR assay using published primers and in vitro transcribed RNA of nucleoprotein (N) gene as positive control was carried out in 169 choanal cleft samples from four districts (Indore, Bhopal, Sagar and Guna). All the samples were found negative for aMPV genome by RT-PCR assay. Overall, 26/263 (9.88%) sera were positive to aMPV antibodies. As the chickens in India are not vaccinated against avian metapneumovirus therefore, this study indicates that layers are exposed to this important poultry pathogen. This study warrants further investigation in wider geographical area and isolation of aMPV to design the control strategies for aMPV.