Lyme disease was discovered in the Connecticut River valley during the 1970s, near the picturesque town of Old Lyme. The cause was identified as an infection from the bacterium Borrelia burgdorferi, carried and spread through ticks and their bite. The Centers for Disease Control (CDC) estimate around 300,000 Americans are diagnosed with Lyme disease each year, and with occurrences now found in all 50 states and the District of Columbia, that number is only set to increase.
The most striking reaction in the vast majority of patients is a large rash, often resembling a bullseye, at the location of the bite. Other symptoms mirror the flu (fever, headache, fatigue, etc.). If the disease goes untreated, these can devolve into severe headaches, a stiff neck, migratory joint pain especially in the knees, and more. “For early Lyme disease, a short course of oral antibiotics such as doxycycline or amoxicillin is curative in the majority of the cases,” the National Institute of Allergy and Infectious Diseases notes. “In more complicated cases, Lyme disease can usually be successfully treated with three to four weeks of antibiotic therapy.”
In most cases, the disease has no lingering effects when treated correctly, even in patients who wait several years to take the recommended amount of antibiotics. A very small cohort of sufferers experience an occasional recurrence of migratory joint pain, which researchers believe is the result of dead Borrelia cells persisting in tissue. While this pain goes away with time, the process can take years. But this is not the same as what some doctors are calling chronic Lyme disease.
Chronic Lyme disease, or CLD, is something else altogether. The symptoms are the same. Pain. Fatigue. Arthritic aches that move between joints. But the suggested treatment takes years, and as the number of Lyme disease cases continues to grow, so does the hype around CLD. “With Lyme disease on the rise, why do so many chronic sufferers struggle to convince doctors they’re sick?” asked NBC News this summer.
The answer could be that while Lyme disease can be diagnosed through two-tier lab testing, chronic Lyme disease is far more mysterious. Paul Lantos, a professor of medicine at Duke University, reported in a paper on the subject that CLD “has no clinical definition and is not characterized by any objective clinical findings.” The CDC says that “in many occasions [chronic Lyme disease] has been used to describe symptoms in people who have no evidence of a current or past infection with B. burgdorferi” and that “experts do not support [the term’s] use.”
Another name often employed is “post-treatment Lyme disease syndrome” (PTLDS), which is used to describe a range of symptoms (fatigue, joint pain, and other ailments) that a small contingent of patients reports months or years after being successfully treated for Lyme disease. These symptoms, however, are hardly unique to Lyme disease.
Virginia’s Loudoun County has a Lyme Disease Commission. Its chair, Dr. Samuel Shor, believes in CLD. His process of diagnosing the disease, he says, is “clinical judgment” and he suggests that lab tests for B. burgdorferi are not sensitive enough to catch chronic Lyme disease. “You look at an individual, you take their history,” Shor explains. “What is the symptom presentation with which an individual is presenting?”
Chronic fatigue is one of the primary symptoms doctors look for in diagnosing CLD. But a national survey by the CDC in 2010-11 found that 15.3 percent of women and 10.1 percent of men had felt “very tired or exhausted” most or every day for the previous three months. Another often-cited symptom for those diagnosed with CLD is chronic pain. But the numbers are even higher for those in the general population reporting pain most or every day; 20.7 percent for women and 16.9 percent for men, according to the CDC.
A 2015 study by researchers at the Medical University of Vienna examined whether people who had Lyme disease are more likely to experience such nonspecific symptoms than those who have not. The study concluded, “it is highly unlikely that the complaints are related to a previous infection with [B. burgdorferi]. The results show that testing patients with nonspecific symptoms for antibodies against [B. burgdorferi] in the everyday clinical setting does not provide any useful information about their aetiology.” In layman’s terms, Lyme disease was not the cause of these nonspecific symptoms.
The treatment Dr. Shor prescribes the patients he diagnoses with CLD generally involves oral antibiotics. “I treat people with them for months. In some cases, years.” But the CDC warns against this practice, noting the unproven benefits of such extended treatment and the potential for “serious complications” with long-term antibiotic use. “There have been at least five placebo-controlled, clinical studies on the benefit of extended antibiotic therapy for the treatment of post-treatment Lyme disease symptoms (PTLDS) that some prefer to call ‘chronic Lyme disease,’ ” says Dr. Philip Baker, executive director of the American Lyme Disease Foundation. “None of them showed any benefit.”
There is also a lack of solid evidence tying PTLDS to Lyme disease. The research purporting to find a causal relationship has relied on questionnaires rather than objective measures. A 2017 study (funded in part by the Global Lyme Alliance, supporters of the CLD diagnosis) attempted to show “evidence of severe and lingering symptoms in some after treatment for Lyme disease” through personal testimony. “We found no truly objective markers of PTLDS on any of these clinically available tests,” the director of the Johns Hopkins Lyme Disease Clinical Research Center, Dr. John Aucott, said of this study of 61 patients. Instead of biological “objective markers” to demonstrate a connection between the symptoms and Lyme disease, the study relied on “differences in the results from the questionnaires” from the small sample. The summary clarified that “this study, and the term ‘PTLDS,’ do not define the cause of the condition,” admitting a lack of solid evidence to tie PTLDS to Lyme disease.
The spread of Lyme disease is certainly cause for concern—a concern that Valneva hopes to address. The biotech company is currently developing a vaccine for the disease and will begin phase two of the clinical trials later this year. Because of the increasing threat of Lyme disease, the FDA approved fast-track designation for the vaccine in 2017. But it can’t be commercially available for years. In the meantime, if you’ve had Lyme disease should you worry about being tired? Or that aching left knee? Which doctor should you trust? It’s a good question—and a reminder of how ever-complicated is the field of medicine and how often doctors and researchers disagree.
