B.U. Bridge is published by the Boston University Office of University Relations.
By Hope Green
With camping and hiking season in full swing, informed vacationers are taking precautions to prevent Lyme disease, a sometimes debilitating ailment transmitted by ticks. In long-term sufferers, it can lead to chronic fatigue, arthritis, ringing in the ears, jaw pain, and even mild memory loss.
Physicians have come a long way in learning how to treat Lyme disease in the past 25 years. But according to one specialist at Boston University Medical Center, the illness re-mains largely underdiagnosed and is a divisive topic within the medical establishment.
Sam Donta, a professor of biomolecular medicine and Lyme disease expert, aims to moderate the debate and educate less knowledgeable health-care practitioners so that more patients can be cured.
“What we’re dealing with is an insidious, chronic disease,” he says. “I’m sure I’m being accused of overdiagnosing or overtreating, but if I am, I seem to be lucky, because my patients are generally responding to what I give them.”
The disease is known to have existed as early as 1909, but gained wide publicity after a cluster of cases was reported in the town of Lyme, Connecticut, in 1975. It has been found throughout the United States as well as in Europe, Asia, Africa, and Australia.
Lyme disease is caused by the bacterium borrelia burgdorferi. It is transmitted by a pinhead-size insect commonly referred to as a deer tick, though the tick is carried by a variety of other mammals and birds as well.
In the early stages of infection, a rash or other distinctive symptoms may appear. Physicians generally agree that a blood test is warranted in such cases. But there is controversy over how to make a diagnosis at a more advanced phase.
“The problem in diagnosing people with the later manifestations of Lyme disease,” says Donta, “is that they don’t have a lot of objective signs. That is, they have all these anecdotal symptoms like fatigue, muscle aches, numbness and tingling, and dizziness, but each of these is difficult to quantify on a physical exam.
“But the crux of the problem,” he adds, “is a lack of sensitivity on the part of many physicians, who are calling these patients depressed or telling them their symptoms are psychosomatic.”
Making diagnosis more complex, adds Donta, is the widespread use of unreliable testing procedures. A superior method known as the Western blot is 80 percent accurate, he says, but many laboratories consider its technology too challenging.
Donta also cites a historical factor in the diagnostic dilemma: early experts on the disease focused on arthritic symptoms. Although subsequent studies concluded otherwise, the belief persists that joint swelling is the most solid clue to an advanced stage of infection.
“A lot of physicians will say, ‘Who has time to listen to a litany of complaints that don’t make any sense?’ ” says Donta. Yet in clinical practice, he has observed that the complaints fit a pattern. A number of illnesses cause one or two of the symptoms his patients describe, he says, but only Lyme disease triggers so many of them at once.
Massachusetts physicians are now required to observe this pattern more closely, because last year the commonwealth revised its official diagnostic guidelines for the disease. Previously, practitioners were allowed to rely on a narrow set of criteria from the Centers for Disease Control (CDC) that is intended for epidemiological studies, rather than for diagnosing individuals. Unfortunately, says Donta, insurance carriers have used this abbreviated list of symptoms to deny treatment.
Donta serves on a Barnstable County task force that offers policy recommendations to the state Department of Health while monitoring Lyme disease on Cape Cod and the islands. The panel was instrumental in revamping the guidelines. “Our hope,” he says, “is that the CDC will advise other states to follow our lead.”
Meanwhile, at BUMC, Donta aims to expand clinical and basic research into Lyme disease, as well as similar infections less widely studied. A milestone was reached in 1998, when he and his research team identified a toxin produced by borrelia burgdorferi that appears to kill nerve cells in culture. If the team can determine how the toxin works, Donta says it could “revolutionize” diagnosis and treatment.
In addition, Donta offers an online Continuing Medical Education course on Lyme disease. He hopes to organize a workshop for specialists. “I think we’re in the midst of understanding what’s going on with Lyme disease,” he says, “but we have a ways to go.”