First detection of Borrelia miyamotoi infections in ticks and humans from the northeast of Inner Mongolia, China

Borrelia miyamotoi is a relapsing fever spirochete that can cause chills, fatigue, headache, myalgia, arthralgia, and even meningitis, damaging human health. B. miyamotoi has a wide distribution since its discovery in Ixodes persulcatus in 1994. The human B. miyamotoi disease was first described in Russia in 2011. However, the epidemiological information in China is limited. Here, we report the molecular detection of B. miyamotoi in the northeast of Inner Mongolia, China. A total of 774 adult ticks and 771 blood samples of patients were collected, from April 2017 to August 2019 in the northeast of Inner Mongolia, and tested for B. miyamotoi using real time-PCR. Gene sequences of 16S rRNA, fla, and glpQ were obtained to reconstruct the phylogenetic relationship of B. miyamotoi from humans and ticks. The results showed the total prevalence of B. miyamotoi in ticks was 1.3% of 774 ticks, with rates of 2.6% in I. persulcatus, 0.78% in Dermacentor nuttalli, 1.3% in D. silvarum, and 0.4% in Haemaphysalis longicornis. Thirteen (1.7%) patients were confirmed as positive for B. miyamotoi. Patients were mainly 50-60-years old and had a history of tick contact. They presented flu-like symptoms, including fever, headache, poor spirit, dizziness, nausea, vomiting, hypodynamic, chest distress, and myalgia. Phylogenetic analysis showed that the B. miyamotoi in the present study belonged to the Siberian type, distinct from European and American types and the I. ovatus isolate from Japan. This is the first report of B. miyamotoi detection in both ticks and humans in the northeast of Inner Mongolia, China, indicating B. miyamotoi is present in the area. These findings suggest that people have a risk of infection with B. miyamotoi in this region, where it should be included the differential diagnosis of tick-borne diseases.