Abstract
Novel Duck
reovirus
(NDRV) is an ongoing non-enveloped virus with ten double-stranded RNA
(dsRNA) genome segments that belong to the genus Orthoreovirus ,
in the family Reoviridae . NDRV-associated spleen swelling and
necrosis disease have caused considerable economic losses to the
waterfowl industry worldwide. Since 2017, a significant number of NDRV
outbreaks have emerged in China. Herein, we describe two cases of duck
spleen necrosis disease among ducklings on duck farms in
Henan
province, central China. Other potential causative agent, including
Muscovy duck reovirus (MDRV), Duck hepatitis A virus type 1 (DHAV-1),
Duck hepatitis A virus type 3 (DHAV-3), Newcastle disease virus (NDV),
and Duck tembusu virus (DTMUV), were excluded by reverse
transcription-polymerase chain reaction (RT-PCR), and two NDRV strains,
HeNXX-1/2021 and HNJZ-2/2021, were isolated. Sequencing and phylogenetic
analysis of the σC genes revealed that both newly identified NDRV
isolates were closely related to DRV/SDHZ17/Shandong/2017. The results
further showed that Chinese NDRVs had formed two distinct clades, with
late 2017 as the turning point, suggesting that Chinese NDRVs have been
evolving in different directions. In conclusion, this study provides an
insight into the ongoing emerged duck spleen necrosis disease, and a
foundation for developing of effective vaccine and control programs.