Scientists have found out why Lyme disease can sometimes linger long after the patient has finished antibiotic treatment that should have wiped it out.
What Is Lyme Disease?
Lyme disease is caused by bacteria called Borrelia burgdorferi, transmitted through the bite of a black-legged tick. Every year 300,000 American are affected.
When people are treated with antibiotics early in the infection, they usually recover without problems. But if the treatment is delayed, and occasionally even when it is given promptly, people may develop joint and muscle pain and debilitating neurological symptoms. This long-lasting version of Lyme disease affects 10 to 20 percent of patients.
The Explanation: Cells That Play Possum
Researchers at Northeastern University found that a small proportion of the bacteria go dormant during treatment to form persister cells. Then, when the treatment is finished, they come out of dormancy and re-activate the infection.
How to Treat Persisters
The researchers tested several possible strategies to counteract persister cells and found one that works well in test tubes. It is called pulsed dosing, hitting the persister cells with a fresh round of antibiotic as they come out of dormancy. Four rounds of antibiotic were effective against all the persister cells in test tubes.
Clinical trials in humans with Lyme disease have yet to be conducted, but the strategy may be promising not only against Borrelia but possibly against other bacteria that go into hiding for long periods of time. We have spoken with researchers who describe Bartonella as behaving like this; Chlamydia pneumoniae also seems to have similar propensity for hiding.
