Going Beyond the Usual
Fallon is a slender man with a tidy salt-and-pepper beard and a soft-spoken manner. The patient briskly outlined the events of the past few months, then described her current symptoms. She had no energy for anything and went to bed right after dinner most nights. She slept but never felt rested. And once she got out of bed, every joint in her body ached; it was the worst in her hands. Both hands? Fallon asked. Yes. And it was a different kind of pain from the many sports injuries she’d had. All she wanted was to feel herself again.
Fallon spent nearly an hour getting the rest of her medical history. But by the end of the visit, he wasn’t at all certain this was Lyme or any tick-borne infection. They can all cause fever and fatigue, but the joint pain in Lyme, the most common of these diseases, was usually limited to one side. Two other common tick-borne infections, ehrlichiosis and anaplasmosis, can produce similar syndromes of fever, fatigue and body pain but are usually far more severe. Babesia, a parasite transmitted by the tick that carries both ehrlichiosis and Lyme disease, was possible, but that infection destroys red blood cells, causing severe anemia along with fever and malaise. Fallon ordered the extensive panel of tests used in his center to look for other infections that ticks can cause.
An Insidious Bite
Because her symptoms weren’t typical, Fallon also ordered tests to investigate other possibilities. Rheumatoid arthritis (R.A.) often causes joint pain that can be worse in the hands. Celiac disease, an autoimmune disorder, can cause this combination of gastrointestinal distress and joint pain. He also checked her thyroid hormones, her red-blood-cell count and calcium level. The results came back over the next couple of weeks: She wasn’t anemic. Her calcium was normal. It wasn’t her thyroid. She didn’t have celiac disease or R.A. She didn’t have Lyme disease either. Nor did she have babesiosis or ehrlichiosis.
Only one result was positive — the test for a distant cousin of Borrelia burgdorferi, the bacterium that causes Lyme. It’s called Borrelia miyamotoi, and it causes one of the newest tick-borne diseases. The first cases, in Russia, were reported in 2011. Cases were reported in the U.S. two years later. B. miyamotoi, like Lyme, is carried by the black-legged deer tick, but it’s a much easier infection to get. With Lyme, the tick has to be attached to a body for two to three days before the bug can be transmitted. That’s because B. burgdorferi lives deep in the tick’s gut. But B. miyamotoi lives in the tick’s mouth and can invade the body almost immediately.
When untreated, B. miyamotoi can cause recurrent episodes of illness because of an unusual ability to fool the immune system by changing its outer layer. Once it has eluded our disease-fighting antibodies by the equivalent of changing clothes, it can reproduce again and produce a new round of fever, headache, fatigue and body pain that characterize this as well as most other tick-borne infections.
Fallon was a little surprised by the unusual result, but it made sense. The patient had been on Long Island where there are many ticks. And she reported this unusual relapsing fever. He called her with the news. She was ecstatic to finally have an answer. The recommended treatment is two weeks of an antibiotic called doxycycline.