Detection, Genetic Characterization, and Evolutionary Analysis of Jingmen Tick Virus in Ticks from Border Regions of Yunnan Province, China

Abstract Background Jingmen tick virus (JMTV), an emerging tick-borne arbovirus of global public health concern, is a segmented positive-sense RNA virus assigned to the genus Flavivirus of the family Flaviviridae. Although JMTV has been detected in ticks and mammals across Asia, Africa, Europe, and the Americas, epidemiological data from the border regions of southwestern China remain limited. This study investigated the prevalence and genetic characteristics of JMTV in ticks collected from border areas of Yunnan Province, China. Methods A total of 1,035 ticks infesting cattle were collected from five border regions of Yunnan (including Ruili and Malipo) between May 2024 and August 2025. Tick species were identified by PCR amplification and sequencing of the mitochondrial COI and 16S rDNA genes. JMTV was detected by RT-qPCR, and genetic and phylogenetic analyses were performed on near-full-genome sequences of positive samples; attempts were made to isolate the virus in Vero, BHK-21, and C6/36 cells and in Kunming mice. Results Three tick species were identified: Rhipicephalus microplus , Haemaphysalis longicornis , and Haemaphysalis bispinosa . The overall JMTV-positive rate was 70.82% (733/1,035), with JMTV detected exclusively in R. microplus ; the regional positive rates were 93.90% in Ruili and 71.33% in Malipo, a statistically significant difference (P < 0.001). Phylogenetic analysis placed all four genome segments (NS1–NS4) of the detected strains within the Asian reference clade, where they formed an independent lineage; the four segments did not cluster entirely on the same branch, indicating host-associated crossover together with a degree of geographic clustering. Attempts to isolate live virus in the three cell lines and in mice were unsuccessful. Conclusions JMTV is highly prevalent in R. microplus along the China–Myanmar and China–Vietnam borders of Yunnan, posing a potential public health risk and providing epidemiological evidence to support local JMTV prevention and control. Because sampling was uneven across regions, more balanced future surveys are needed to refine regional epidemiological estimates.