Isolation and characterization of Iwanai Valley virus, a new tick-borne nairovirus from Ixodes ovatus ticks in Hokkaido, Japan A novel nairovirus from ticks

• Published in: Archives of virology Vol. 170; no. 1
• Main Authors: Matsumura, Ryo, Kobayashi, Daisuke, Yamauchi, Takeo, Park, Eunsil, Nishino, Ayano, Maeda, Ken, Kasai, Shinji, Itoyama, Kyo, Isawa, Haruhiko
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.01.2025
• Subjects: Biomedical and Life Sciences; Biomedicine; Infectious Diseases; Medical Microbiology; Original Article; Virology
• DOI: 10.1007/s00705-024-06195-0
• ISSN: 0304-8608

Most members of the genus Orthonairovirus , represented by Crimean-Congo hemorrhagic fever virus and Nairobi sheep disease virus, are tick-borne, and some have become a public health concern in recent years. Here, we report the isolation and genetic and biological characterization of a new orthonairovirus, designated as "Iwanai Valley virus" (IWVV), from Ixodes ovatus ticks in Hokkaido, Japan. The amino acid sequence of the viral nucleoprotein (NP) was found to be 34–45% identical to those of known orthonairoviruses. Phylogenetic analysis based on amino acid sequences of the viral NP revealed that IWVV is closely related to human-pathogenic tick-borne orthonairoviruses, including Songling virus, Tacheng tick virus 1, and Yezo virus, which were recently discovered in East Asia. BHK-21 (Syrian hamster kidney), Vero (African green monkey kidney), SW-13 (human adrenal adenocarcinoma), HuH-7 (human hepatocellular carcinoma), and ISE6 ( Ixodes scapularis tick embryo) cells were found to be susceptible to IWVV infection. Notably, several human-derived cell lines supported efficient replication of the virus. Our findings provide new insights into the diversity, evolutionary dynamics, and geographical distribution of orthonairoviruses in East Asia.