Viromes of Haemaphysalis longicornis reveal different viral abundance and diversity in free and engorged ticks

Haemaphysalis longicornis ticks,commonly found in East Asia,can transmit various pathogenic viruses,includingthe severe fever with thrombocytopenia syndrome virus(SFTSV)that has caused febrile diseases among humansin Hubei Province.However,understanding of the viromes of H.longicornis was limited,and the prevalence ofviruses among H.longicornis ticks in Hubei was not well clarified.This study investigates the viromes of bothengorged(fed)and free(unfed)H.longicornis ticks across three mountainous regions in Hubei Province from 2019to 2020.RNA-sequencing analysis identified viral sequences that were related to 39 reference viruses belonging tounclassified viruses and seven RNA viral families,namely Chuviridae,Nairoviridae,Orthomyxoviridae,Parvoviridae,Phenuiviridae,Rhabdoviridae,and Totiviridae.Viral abundance and diversity in these ticks were analysed,andphylogenetic characteristics of the Henan tick virus(HNTV),Dabieshan tick virus(DBSTV),Okutama tick virus(OKTV),and Jingmen tick virus(JMTV)were elucidated based on their full genomic sequences.Prevalenceanalysis demonstrated that DBSTV was the most common virus found in individual H.longicornis ticks(12.59%),followed by HNTV(0.35%),whereas JMTV and OKTV were not detected.These results improve our understanding of H.longicornis tick viromes in central China and highlight the role of tick feeding status and geographyin shaping the viral community.The findings of new viral strains and their potential impact on public health raisethe need to strengthen surveillance efforts for comprehensively assessing their spillover potentials.