Borrelia miyamotoi Disease
What is Borrelia miyamotoi?
Borrelia miyamotoi is a bacterium in the relapsing fever group of Borrelia spirochetes. It is related to, but distinct from, the bacteria that cause Lyme disease (B. burgdorferi). UKHSA reported B. miyamotoi in host-seeking Ixodes ricinus ticks in England.
No human infections have been detected in the UK. Awareness is growing as diagnostic and surveillance methods improve.
How Does it Differ from Lyme Disease
- B. miyamotoi belongs to the relapsing fever group, not the Lyme disease group of Borrelia.
- It typically causes recurrent episodes of fever rather than the bullseye rash seen in Lyme disease.
- Standard Lyme disease blood tests do not detect it, so specific testing is needed.
- Unlike Lyme disease, B. miyamotoi can potentially be transmitted within hours of a tick attaching, because the bacteria can be present in the tick’s salivary glands (not only the gut).
Signs & Symptoms
Symptoms typically appear within 2 weeks of an infected tick bite:
- Relapsing fever — episodes of high fever that come and go
- Headache and fatigue
- Muscle and joint pain
- Chills and sweats
A bullseye rash is not typical. Severe cases can occur in immunocompromised individuals. Most infections in otherwise healthy people are thought to be mild or self-limiting.
Diagnosis & Treatment
Diagnosis requires specialised blood tests; routine Lyme disease serology will not pick it up. If you have unexplained relapsing fever after a tick bite, mention the tick exposure to your GP.
Treatment is with doxycycline or other antibiotics, similar to Lyme disease. Response to treatment is generally good.
Prevention
- Follow our bite prevention guide.
- Remove ticks as quickly as possible — though transmission may occur sooner than with Lyme disease.
- There is no vaccine.
References & Further Reading
Ixodes ricinus (UK tick association) · Lyme Disease · Dashboard