B. miyamotoi

What you need to know about Borrelia miyamotoi

What is Borrelia miyamotoi?

Borrelia miyamotoi is a type of spiral-shaped bacteria that is closely related to the bacteria that cause tickborne relapsing fever (TBRF). It is more distantly related to the bacteria that cause Lyme disease. First identified in 1995 in ticks from Japan, B. miyamotoi has since been detected in two types of North American ticks, the blacklegged or “deer” tick (Ixodes scapularis) and the Western blacklegged tick (Ixodes pacificus). These ticks are already known to spread the germs that cause several diseases, including Lyme disease and anaplasmosis.

What are the symptoms of B. miyamotoi disease?

In a 2015 studyexternal icon of patients with this infection, the most common symptoms were fever, chills, and headache. Other common symptoms included body and joint pain and fatigue. Rash was uncommon, with fewer than 1 in 10 patients developing a rash.

What type of testing is available for patients who might be infected?

Healthcare providers can order blood tests to determine if a person may be infected with B. miyamotoi. Two types of laboratory tests are available:

  • Polymerase chain reaction (PCR) tests that detect DNA from the bacteria
  • Serologic tests that detect antibodies made by the body in response to infection

CDC also provides laboratory diagnostic support for B. miyamotoi infections at the request of state health departments.

How is B. miyamotoi treated?

B. miyamotoi infections are treated with a 2- to 4-week course of the antibiotic doxycycline. Amoxicillin and ceftriaxone have also been successfully used.

What more do researchers need to know?

Since this is a relatively new and rare disease in the United States, researchers and healthcare providers are working to answer basic questions including:

  • What are the signs and symptoms of illness?
  • Where is B. miyamotoi found?
  • How common is infection?
  • Who is at greatest risk for infection?

What is CDC doing?

CDC is working to:

  • Detect and track cases in people.
  • Determine where B. miyamotoi is found and how common infection is.
  • Analyze blood samples for B. miyamotoi and other tickborne germs using advanced molecular detection methods.

How can I avoid this disease?

Reducing exposure to ticks is the best defense against tickborne infections. For more information, see Preventing Tick Bites.