Detection of virulent Newcastle disease virus in chicks by real-time RT-PCR

A real-time RT-PCR assay was established to detect Newcastle disease virus(NDV) in 18-day-old chicks infected with virulent NDV H2 strain and chicks in direct-contact with the infected chicks.By real-time PCR detection,the lung,brain,spleen,kidney and intestine from the experimentally infected chicks were positive for NDV RNA at hour 6 post-infection(PI),and all tissue specimens were positive at hour 12 PI.The lung,brain,spleen,and kidney from the chicks infected by direct-contact were positive at hour 12 PI and all specimens from these chicks were positive for viral RNA at hour 24 PI.The order of tissues with NDV RNA load from high to low was the lung,brain,spleen,kidney,intestine,liver,heart and leg muscle.The real-time RT-PCR had similar sensitivity with the conventional RT-PCR in sensitivity.