Prevalence and Diversity of Severe Fever with Thrombocytopenia Syndrome Virus and Co-Infection with Babesia microti in Ticks from Central and Eastern Parts of China

This study was conducted to investigate tick species that may harbour severe fever with thrombocytopenia syndrome virus (SFTSV) and <i>Babesia microti</i> in the provinces of Henan, Anhui, and Zhejiang, as well as in Shanghai in the central and eastern parts of China. Between March and September 2023, 721 pools of ticks were collected belonging to three genera and five species: <i>Haemaphysalis longicornis</i> (<i>n</i> = 612; 84.9%), <i>Haemaphysalis fusca</i> (<i>n</i> = 94; 13.0%), <i>Rhipicephalus microplus</i> (<i>n</i> = 10; 1.4%), <i>Amblyomma testudinarium</i> (<i>n</i> = 3; 0.4%), and <i>Haemaphysalis wellingtoni</i> (<i>n</i> = 2; 0.3%). The SFTSV-positive pool rate was 20.0%, 13.0%, 5.8%, and 4.1% in Xinyang, Henan; Songjiang, Shanghai; Lu'an, Anhui; and Zhoushan, Zhejiang, respectively. SFTSV was detected in all five tick species collected. Among the SFTSV-positive pools, <i>H. longicornis</i> constituted the highest proportion (83.9%, 78/93), whereas pools containing <i>R. microplus</i> and <i>H. wellingtoni</i> each represented the lowest proportion (1.1%, 1/93). <i>Babesia microti</i> was assayed only in these SFTSV-positive tick pools, and co-infection was found in both <i>H. longicornis</i> and <i>H. wellingtoni</i>, though it was most frequent in <i>H. longicornis</i>.