Objective To understand the related situation of arthritis patients, livestock, small mammals and vector tick infection and carrying Borrelia burgdorferi in Tengchong city, Gaoligong Mountain hinterland of Yunnan province from 2015 to 2025.

Methods The level of Lyme disease antibody in patients with arthritis was detected by ELISA. The 5S−23S rRNA (252bp) gene of Borrelia burgdorferi was amplified by nested PCR and sequenced to detect the infection status of Borrelia burgdorferi in livestock, small mammals and ticks.

Results Among 80 patients with unexplained arthritis, 26 cases were positive for Lyme disease IgG antibody, with a positive rate of 32.50%(26/80). Among 758 blood samples from cattle and sheep, only one cattle sample was detected with B. sinica genotype, with a positive rate of 0.13%(1/758). A total of 345 small mammals belonging to 3 orders, 7 families, 18 genera and 29 species were detected. Borrelia valaisiana infection was detected in only one Rattus andamanensis, with a positive rate of 0.29%(1/345). A total of 566 ticks belonging to 1 family, 4 genera and 7 species were detected, and 44 ticks belonging to 3 species were positive, with a positive rate of 7.77%(44/566). Four genotypes of Borrelia burgdorferi were detected: B. garinii, B. afzelii, B.valaisiana and B.sinica. The same Borrelia burgdorferi genotypes B.valaisiana and B.sinica detected in vectors and host animals had high similarities, reaching 97.25%−99.61% and 99.00%−99.60%, respectively, and the genetic evolution relationship was close.

Conclusion The prevalence of Lyme disease exists in specific populations, hosts and vectors in Tengchong city, Yunnan province.There are at least two pathogenic genotypes for humans. The sequence similarity of the same genotype Borrelia burgdorferi detected in hosts and vectors is high, and there may be a transmission chain.