Metagenomic profiling of tick-borne viromes across four ecologically diverse provinces in China

Ticks are important vectors of emerging viruses, and China's ecological landscapes may influence the transmission dynamics of tick-borne viruses (TBV). In 2021, a total of 2867 ticks collected from Inner Mongolia, Hebei, Hunan, and Hainan provinces were subjected to metagenomic sequencing to characterize TBV diversity. A total of eleven TBVs were identified, comprising three members of the family Phenuiviridae (severe fever with thrombocytopenia syndrome virus, Lihan tick virus, Dabieshan tick virus), three belonging to Nairoviridae (Huangpi tick virus 1, Shanxi tick virus 2, Henan tick virus), one in Chuviridae (Wuhan tick virus 2), one in Rhabdoviridaes (Wuhan tick virus 1), and three unclassified viruses (Hubei tick virus 2, Bole tick virus 4, and Tacheng tick virus 7). Viral composition varied significantly across tick species and geographic regions, with phylogenetic analysis revealing distinct regional clustering patterns. Notably, Lihan tick virus was detected for the first time in Hunan Province, Bole tick virus 4 was identified in argasid ticks from Inner Mongolia for the first time, and a novel lineage of severe fever with thrombocytopenia syndrome virus was discovered in Shijiazhuang, Hubei Province. These findings underscore substantial TBV diversity shaped by tick species and geographic origin, emphasizing the necessity for ongoing surveillance to guide the development of targeted prevention and control strategies.