Prevalence of three important tick-borne pathogens in ticks and humans in Shaanxi Province, Northwest China.

The investigation of important prevalent tick-borne pathogens is central to the control of tick-borne diseases. To understand the prevalence of Borrelia burgdorferi s.l., Borrelia miyamotoi, and the Alongshan virus in ticks and patients in Shaanxi Province, China, a total of 670 adult ticks and 524 patient blood samples were collected in the region between 2022 and 2023. In this study, PCR was used to estimate the prevalence of the three pathogens. The results revealed that the overall positive rates of B. burgdorferi s.l, B. miyamotoi, and ALSV infection in the collected ticks were 13.58 %, 2.46 %, and 4.17 %, respectively. Three genospecies of B. burgdorferi s.l. were detected in this study, namely, B. garinii, B. afzelii, and B. bavariensis, with positive rates of 4.63 %, 3.58 %, and 5.37 %, respectively. The prevalence rates of B. miyamotoi, ALSV  and B. burgdorferi s.l. in the patients were 0.38 %, 0.95 %, and 15 %, respectively. Moreover, B. burgdorferi s.l. and ALSV coinfection was also detected in three patients. Evolutionary analysis revealed that the isolate of B. miyamotoi belongs to the Asian type (Siberian type) and that of ALSV is closely related to that of Finland. To our knowledge, this is the first report on B. miyamotoi and ALSV detection in both ticks and humans in Shaanxi Province; the prevalence indicates that the regions in this province might be endemic areas. The results also suggest that humans in these regions are at risk of infection with these three tick-borne diseases.