Borrelia miyamotoi is a spirochete bacterium in the genus Borrelia. A zoonotic bacterium, B. miyamotoi can be transferred to humans through the deer tick (Ixodes scapularis), the same tick species that spreads B. burgdorferi, the causative agent of Lyme disease, and Babesia microti, the causative agent of babesiosis. Although infection can cause some similar symptoms including fever, headache, fatigue, and muscle aches, acute Lyme disease often presents with rash, while infection with B. miyamotoi does not; it remains unclear whether B. miyamotoi causes a relapsing fever syndrome.