About Borrelia Miyamotoi Disease
Borrelia miyamotoi was first found in ticks in Japan in 1995 and was recognized as a cause of human illness in Russia in 2011 and in the United States in 2013. It is a relapsing fever Borrelia, a cousin of the Lyme bacterium, but it is carried by hard ticks, the blacklegged tick (Ixodes scapularis) in the East and Midwest and the western blacklegged tick (Ixodes pacificus) on the Pacific coast. The CDC now calls the illness hard tick relapsing fever. Unlike Lyme disease, it can pass from an adult female tick to her eggs, so even larval ticks can be infected.
The illness looks like a bad flu in summer: high fever, chills, severe headache and body aches, often with low white blood cells, low platelets and raised liver enzymes. There is usually no rash. Evidence suggests most people have a single fever episode, with relapses in about 10% of cases. Many people recover on their own, but severe disease, including meningoencephalitis, has been reported, mostly in people with weakened immunity. In the Northeast case series, symptoms resolved after doxycycline and no chronic problems were seen.
Standard Lyme disease antibody tests do not reliably detect B. miyamotoi, and relapsing fever infections can also cause a false positive Lyme test, so a doctor who suspects it needs to order a specific PCR, which is available from some commercial labs and most useful in the first days of illness. Antibody tests for B. miyamotoi work best 2 weeks or more after symptoms begin. The CDC says a 2-week course of oral doxycycline or amoxicillin is effective for most patients, including young children, with intravenous ceftriaxone for severe or hospitalized cases.
Common Symptoms of Borrelia Miyamotoi Disease
Recognizing the signs of Borrelia Miyamotoi Disease early can lead to faster diagnosis and better outcomes. Symptoms may vary in severity from person to person. If you or a loved one are experiencing any of the following, consider speaking with a specialist.
- Sudden fever, often high, about 2 weeks after a tick bite
- Chills, shaking and drenching sweats
- Severe headache and muscle and joint aches
- Fatigue, nausea or vomiting
- Fevers that return after a break, in about 10% of cases
- Rarely, meningoencephalitis, mainly in people with weakened immunity
Who Borrelia Miyamotoi Disease Affects
People in the upper Midwest, Northeast, mid-Atlantic and Pacific coastal states where blacklegged and western blacklegged ticks live. Cases peak in August, later than Lyme disease. People with weakened immune systems, including those on rituximab, are at risk of severe illness including meningoencephalitis. The longer a tick stays attached, the more likely it is to transmit the bacteria.
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FDA-Approved Treatments for Borrelia Miyamotoi Disease
There is currently 1 FDA-approved medication for Borrelia Miyamotoi Disease. These therapies represent the current standard of care and may be used alongside or compared against investigational treatments in active clinical trials.
Source: openFDA drug labeling data. This list may not include all treatments. Always consult your doctor.
Help Paying for Borrelia Miyamotoi Disease Treatment
Charity funds and drugmaker programs for Borrelia Miyamotoi Disease, checked at the source.
- Vibramycin (Doxycycline) · Generic from many makers
Side Effect Explorer
Real-world side effect reports from the FDA Adverse Event Reporting System (FAERS). Includes both FDA-approved drugs and investigational therapies from active clinical trials. Click any drug to see what patients reported.
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Diagnosis and Testing
Tick-borne bacterial infection (Borrelia miyamotoi), diagnosed by PCR or specific antibody tests; not genetic.
Trusted Borrelia Miyamotoi Disease Resources
Reputable organizations and medical references for learning more about Borrelia Miyamotoi Disease, including disease registries, foundation resources, and clinical guidelines.