Abstract

The epidemiology of circulating Newcastle disease virus in village chickens, using hemagglutination inhibition, RT-PCR and real-time RT-PCR was conducted by using systematic random sampling design for collection of samples. Total 1050 sera samples and 1820 tracheal and cloacal swabs were tested from chickens in 21 villages in Fars province, Iran. Samples were collected in January and February 2010. Hemagglutination inhibition test was used to screen the collected sera. RT-PCR and real time RT-PCR tests were used for virus detection in tracheal and cloacal swabs. The performed survey showed that chickens in thirteen (61.9%) villages (epidemiological units) were sero-positive, but no virus was detected in RT-PCR tests. Hemagglutination inhibition antibody titer varied from nil to 28 in the chicken sera. The chicken in the studied area were not vaccinated against Newcastle disease virus, but some of them showed high antibody titer (up to 28). This study shows that a pathogenic Newcastle disease virus is circulating in the area and it could be regarded as a potential threat to poultry industry at the studied area. 

Key words: Newcastle disease, village chickens, RT-PCR, real-time RT-PCR.