Identification of a novel orthonairovirus from ticks and serological survey in animals near China-North korea border.

Emerging pathogenic tick-borne viruses (TBVs) have attracted a great deal of attention due to their significant impact on human and animal health. A novel orthonairovirus named Dadong virus (DDV) was isolated from Haemaphysalis concinna ticks in the Changbai Mountain region on the China-North Korea border. DDV can induce cytopathic effects in mammalian and human cell lines. Phylogenetic analysis showed that it belongs to the genus Orthonairovirus, family Nairoviridae, exhibiting 72.4%-81.3% nucleic acid identity to Tofla orthonairovirus, known to cause lethal infection in IFNAR KO mice. The first serological evidence of DDV circulating in cattle and mice was also obtained, with 4.0% (1/25) of cattle and 2.27% (1/44) of mice seropositive for DDV. Further investigations, including serological surveys using human samples, are required to assess the public health risk posed by DDV.