Borrelia miyamotoi

Ticks can transmit a new Lyme-like disease

Howard LeWine, M.D.

Chief Medical Editor, Harvard Health Publishing

There are several good reasons to keep ticks off your body. One is that they are creepy and suck your blood. Others are the 14 diseases they are known to transmit. A report published online this week in the Annals of Internal Medicine describes the newest tick-borne disease in North America, which is caused by a bacterium known as Borrelia miyamotoi. This spiral-shaped bacterium is related to the one that causes Lyme disease. Like Lyme disease, Borrelia miyamotoi disease is spread by small, hard-bodied deer ticks. Infection with Borrelia miyamotoi often causes a recurring fever, as well as headache, muscle aches, and chills. It does not usually cause the “bull’s eye” rash seen in some people with Lyme disease. According to the Annals report, nearly one-quarter of people diagnosed with Borrelia miyamotoi disease are so sick they need to be hospitalized. The best therapy so far is the oral antibiotic doxycycline. Experts aren’t sure how common Borrelia miyamotoi disease is because it isn’t on doctors’ radar screens, and because some people who develop it never see a doctor.