Until now, most doctors treat Lyme disease with a two to four week course of antibiotics. But if symptoms persist after that, medical guidelines recommend against antibiotic retreatment. It seems this is all subject to change.
Allison DeLong, a biostatistician at Brown University's Center for Statistical Sciences, has published a study questioning Lyme retreatment guidance. Lyme disease is caused by the tick-borne spirochete ‘Borrelia burgdorferi’. Long-term persistent illness following antibiotic treatment is not uncommon, particularly when treatment is delayed. Current treatment guidelines for persistent disease primarily rely on findings from four randomized, controlled trials (RCTs), strongly advising against retreatment.
For DeLong, the four studies do not prove that retreatment does not work: “a lack of evidence should not be used to deny treatment when the studies have serious flaws”, she said. DeLong and three co-authors found evidence in the trials are, more often than not, inconclusive.
Dr DeLong had been concerned about Lyme disease for over a decade; it was not until 2009 when she and her colleagues decided to look into the matter with full statistical rigor. The most influential studies were conducted by Klempner et al., and published together in the New England Journal of Medicine in 2001.
The multicenter trials enrolled chronic Lyme sufferers, patients either received intra-venous antibiotics followed by oral antibiotics or an intra-venous placebo followed by an oral placebo. Klempner and colleagues found no significant benefit to retreatment. “Klempner's statistics showed that treatment might or might not have been effective given the broad range of statistical measure known as the confidence interval”, DeLong said.
In another of the four trials conducted by Krupp et al., researchers found that retreatment produced a significant benefit for fatigue, but the authors of the study mistakenly discounted that result. The authors became concerned that their results were tainted by too many subjects realizing that they were receiving real treatment instead of the placebo. The measure of fatigue is subjective and could be influenced by that realization. But DeLong found that the subjects weren't likely to have realized anything.
“Ultimately”, DeLong said, “the best evidence to support or refute antibiotic retreatment will come when scientists develop a definitive test for active Lyme disease infection.” In the interim, it is possible that chronic Lyme disease patients harbor an ongoing infection that antibiotics could treat.
Written by Alejandro Balbuena for The All Results Journals.