Monitoring of Newcastle disease in poultry at migratory birds landing sites: Mangue Seco and Cacha Pregos between 2013 and 2014*

Abstract

The poultry industry has been considered one of the most efficient agricultural activities, placing Brazil in the ranking of the largest producers of chicken meat. However, a threat to the poultry production chain is the entrance of Newcastle disease virus (NDV) in the country, which would bring huge economic and social losses. Monitoring of the virus was conducted in domestic poultry (Gallus gallus domesticus) farms on the migratory birds landing sites Mangue Seco and Cacha Pregos between 2013 and 2014 to control Newcastle disease (NCD) in these locations. Activities in health education, filling the questionnaire to define the sanitary profile of the farms, georeferenced registration and collection of blood samples, cloacal and tracheal swabs of the backyard birds were the epidemiological surveillance actions performed. A total of 133 serum samples were analyzed in Mangue Seco and 81 in Cacha Pregos. The results showed that both Mangue Seco (63.4%) and Cacha Pregos (88.9%) presented reactive animals for the NDV. The results of real-time polymerase chain reaction (RT-PCR) and viral isolation analyses were negative, proving that the domestic poultry were not eliminating the virus at the time of sample collection. The high percentage of reactive animals by indirect ELISA test in both epidemiological units studied suggests the presence of NDV circulating lentogenic strain, since there was no death registration and the birds did not have characteristic symptoms of the disease.