Virome analysis of tick-borne viruses in Heilongjiang Province, China

Ticks are implicated in the transmission of various human and livestock pathogens worldwide. This study aimed to understand the geographical distribution of tick species, along with tick-associated viruses, in Heilongjiang Province, northeast China. Molecular methods were used to classify tick species, with next-generation sequencing and polymerase chain reaction-based analyses used to assess the viromes of ticks from four representative sampling locations in the Greater Khingan Mountains. Five species of ixodid ticks were identified, including Ixodes persulcatus, Dermacentor nuttalli, Dermacentor silvarum, Haemaphysalis longicornis, and Haemaphysalis concinna. From the 1102 ticks, 3,568,561 high-quality reads were obtained by next-generation sequencing. Following trimming, 302,540 reads were obtained, of which 6577 (2.16%) reads were annotated to viruses. Phylogenetic analysis revealed that the viral sequences shared a close relationship with Orthonairovirus, Phlebovirus, deer tick Mononegavirales-like virus, and Jingmen tick virus sequences, but the significance of these newly-identified tick-borne viruses to human and animal health requires further investigation. The results of this study provide a basis not only for further studies on the relationship between ticks and tick-borne viruses, but also for preventing future tick-borne epidemic outbreaks by means of vector control.