Emergence of spontaneously occurring neoplastic disease caused by reticuloendotheliosis virus in breeding Muscovy ducks in China, 2019.

Abstract

Reticuloendotheliosis virus (REV) has a wide range of avian hosts leading to reticuloendotheliosis, and its characteristic of vertical transmission makes it to be one of the most important diseases in breeder avian populations. Up to date, reports on neoplastic disease caused by REV in breeding ducks are few. Here, spontaneously occurring neoplastic disease caused by REV in breeding Muscovy ducks was reported in Guangdong province, China. The most significant gross lesions of sick ducks were tumour-bearing liver and enlarged spleen. Histopathological examination found proliferation of malignant lymphoreticular cells in the liver and reticuloendothelial cells in the spleen. REV strain, CH-GD2019, was successfully isolated using DF-1 cells, and the presence of REV was confirmed by PCR detection and transmission electron microscopy. The length of complete proviral genome is 8,238 nucleotides. Genetic and phylogenetic analyses revealed that CH-GD2019 was closely related to chicken-origin REV strains circulating in China. The results will provide a basic data for better understanding of REV in breeding ducks and suggest that REV from chickens may be a threat to ducks.