Extensive diversity of RNA viruses in ticks revealed by metagenomics in northeastern China

Author summary Ticks are important vectors to transmit many infectious agents. In recent years, many novel tick-borne viruses associated with human illness, including Alongshan virus, Songling virus, and Beiji nairovirus, have been identified in northeastern China. It is necessary to conduct routine surveillance of tick-borne viruses in ticks, however, little is known about the tick virome in northeastern China. In this study, we used metatranscriptomics to investigate the virome diversity in four tick species collected from northeastern China. In total, we identified 22 RNA viruses belonging to eight virus families (exclude an unclassified virus). Of these, five members were established human pathogens, eight viruses were of novel species, and six viruses had close relationship with pathogenic tick-borne viruses with potential public health threats. Moreover, we found that the viromes were significantly affected by the tick species and geographical location in the study. These findings revealed an extensive diversity of RNA viruses in ticks in northeastern China, which will lay the foundation for the prevention and control of emerging tick-borne diseases.