Genetic diversity of Theileria species identified from questing and parasitic ticks in selected areas in Qinghai, China.

Piroplasmosis caused by tick-borne piroplasm is a vital zoonotic disease that poses significant concerns for human and animal health. However, the information on the molecular prevalence of the piroplasm transmitted by ticks is limited in Qinghai, China. Here, we investigated the geographic distribution of 544 collected ticks and the genetic diversity of tick-borne piroplasm in four areas of Qinghai. The results of the tick species identification revealed that the obtained ticks were Haemaphysalis qinghaiensis, Dermacentor everestianus, D. silvarum and D. nuttalli. Nested PCR revealed that the overall prevalence of piroplasm was 25% and included Theileria luwenshuni, T. equi, T. uilenbergi, Theileria sp. OT3 and T. ovis. Furthermore, the phylogenetic trees revealed that the piroplasm carried by ticks was individually clustered with piroplasm carried by various ticks in different regions, and the genotype of T. equi was found to be type B. The present study revealed that the distributions of tick species and the piroplasm carried by ticks in some areas of Qinghai Province are high diverse and distinct spatial heterogeneity. Moreover, Theileria sp. OT3 and T. equi were first discovered in ticks distributed in Qinghai Province, indicating that the epidemic risk of piroplasm transmitted by ticks is increasing, providing a theoretical foundation for the prevention and control of tick-borne piroplasmosis in this region.