Isolation, Genomic Characterization, and Pathogenicity of a Novel Duck Orbivirus Genetically Similar to Corriparta Virus in China.

Corriparta virus (CORV), an arbovirus within the Orbivirus genus, exhibits a broad vertebrate host range but limited pathogenicity. In this study, we report the first isolation and characterization of a novel orbivirus genetically related to CORV, temporarily designed as novel duck orbivirus (NDORV), from Beijing ducks in Henan province, China, in 2024. Genomic characterization revealed that NDORV possesses a 10-segment double-stranded RNA (dsRNA) genome, consistent with the structural hallmarks of the Orbivirus genus, with a high genetic similarity to Parry's Lagoon virus (PLV) and CORV. To evaluate its pathogenicity, specific pathogen-free (SPF) ducks were experimentally inoculated with NDORV. Gross pathological examination revealed splenomegaly and blood stasis as primary lesions, with no mortality observed. Histopathological analysis identified tissue damage in the spleen, lungs, heart, liver, and kidneys. The highest viral loads were observed in the spleen and lungs, peaking at 3 days postinoculation (dpi). This study provides the first comprehensive characterization of a novel orbivirus genetically akin to CORV isolated from ducks in China. These findings highlight the potential prevalence of NDORV in domestic duck populations and underscore the urgency of enhanced surveillance and research on CORV-related arboviruses.