Patients who’ve been treated for Lyme disease but still suffer from its crushing fatigue, aching muscles, stiff joints and other symptoms will not be helped by additional longer-term courses of antibiotics, a new study shows.
Dutch researchers found that a 12-week antibiotic treatment provided no more relief than placebo for patients with persistent symptoms, according to the study published in the New England Journal of Medicine.
That doesn’t mean patients are imagining their symptoms, said study coauthor Dr. Bart Jan Kullberg, a professor of medicine and infectious diseases at the Radboud Medical Center.
“I think part of the problem is that physicians tend to deny the symptoms or the severity of the disease, which isn’t very helpful if you are sick,” Kullberg said. “What is clear to me is that these patients are really sick and have a serious problem that is not easy to solve."
Each year approximately 30,000 people will be diagnosed with Lyme disease, according to the Centers for Disease Control and Prevention. The disease is caused by a bacterium carried and transmitted by deer ticks. While most people fully recover when given a course of antibiotics, about 10 to 20 percent may have persistent symptoms, says Dr. Michael Melia, a coauthor of the editorial accompanying the new study and an assistant professor of medicine and director of infectious disease fellowship training at the Johns Hopkins University School of Medicine.
Some suspect that chronic symptoms are more likely if initial treatment is delayed. But even among patients who are diagnosed and treated quickly, 10 percent will end up with lingering symptoms, Kullberg said.
For the new study, Kullberg and his colleagues treated 280 patients with intravenous antibiotics for two weeks. Then patients were randomly assigned to one of three groups: a 12-week course with doxycycline, clarithromycin or a placebo.
“We had patients report many aspects of their quality of physical and mental health at 3, 6, 9 and 12 weeks after treatment,” Kullberg said. “They were very consistent in reporting that they didn’t feel any benefit of the prolonged course compared to the placebo.”
Dr. Andrew Nowalk hopes that this kind of research will put an end to the antibiotic discussion and allow researchers to focus on the important question: why do some people remain ill while most get better after the standard therapy for Lyme disease?
“Let’s do some really good science to figure out the biological basis for why these patients still feel sick,” said Nowalk, a Lyme specialist and an assistant professor of pediatrics at the University of Pittsburgh. “I think the continued focus on long courses of antibiotics is a disservice to these patients.”
One possible explanation is that infection with the Lyme bacterium may alter the way some people’s immune systems function, Melia said. “There is a small percentage of patients who are left with lasting symptomatology a result of an infection of any kind,” he explained. “It can happen with the Epstein Barr virus, for example.”
Another possibility suggested by animal research is that in some people Lyme can cause permanent changes to the linings of the blood vessels, the heart and joints, said Richard Pollack, an epidemiologist from at Harvard University’s School of Public Health. “Yet others may have other tick borne infections,” Pollack said. “For instance, some may suffer from human babesiosis.”
Ultimately, answers may come from ongoing research being done by Kullberg’s group. They are currently following patients newly diagnosed with Lyme to see if there are any discernible differences between those who are easily cured with a short course of antibiotics and those who end up with persistent symptoms.