Evidence of Viral Reticuloendotheliosis in Muscovy Ducks

The diseases caused by reticuloendotheliosis virus (REV) are generally characterized by immunosuppression occurred to avian species. They can result in the increased susceptibility to secondary bacterial or viral infections and poor immune responses to vaccines on the infected birds. An epidemic of the viral diseases can lead to disastrous impacts for the poultry industry. This study employed the specific primers-pair targeting the long terminal repeat of the virus genomic sequence for an investigation on 21 samples from the infected Muscovy ducks (12 from Fujian and 9 from Zhejiang) collected in 2013. Among the samples, one from Fujian (designated as strain REV-FJ-MD01) and another from Zhejiang (designated as strain REV-ZJ-MD01) were identified for further study. The positive fragments were harvested, cloned, and sequenced. The obtained sequence shared a perfect nucleotide identity with other GenBank REV isolates, except the pigeon-origin REV and the duck-origin REV strain 173, which differed on only one nucleotide. The genetic evolutionary relationship between the two strains and REV appeared close. Therefore, it was concluded that REV infection existed in the Muscovy ducks in Fujian.