Detection of Newcastle disease virus in backyard poultry in Chile

Objective. To identify the presence of Newcastle disease virus (NDV) in birds from backyard production systems (BPS) in parts of the central zone of Chile. Materials and methods. Between 2013 and 2015, a total of 1.579 orotracheal swabs were collected form chickens, turkeys, ducks and geese belonging to 328 BPS from the central zone of Chile. In each BPS, swabs collected from birds of the same specie were grouped in the same tube with transport medium forming a pool composed of no more than 5 samples. Pools were analyzed by real time RT-PCR. Results. Out of a total of 364 pools, 6 were positive for NDV. All positive pools corresponded to chickens from the regions of Valparaíso (n=1) and Libertador General Bernardo O'Higgins (n=5). Pools corresponding to turkeys, ducks or geese were diagnosed as negative. Conclusions. The positive results demonstrate the presence of NDV in BPS in Chile. This could be due to the circulation of lentogenic strains of the virus transmitted by wild birds or to the contact with vaccinal strains administered in industrial production systems whose vaccinated birds may end up in BPS.