New Findings Distinguish Between Relapse and Reinfection in Recurrent Lyme Disease

Date: November 14, 2012
Media Contact:

Donna Moriarty
(914) 594-4536

NYMC researchers, comparing genetic profiles of strains, conclude that recurrent episodes are new infections.

Valhalla, N.Y. — New findings released this week make a clear distinction between repeat episodes of early Lyme disease in a single individual. A research team led by Robert B. Nadelman, M.D., professor of medicine in the Division of Infectious Diseases at New York Medical College and the Lyme Disease Diagnostic Center, concluded that recurrences of Lyme disease are the result of reinfection and not a relapse of the original infection.

The study, “Differentiation of Reinfection from Relapse in Recurrent Lyme Disease,” will be published as the lead paper in the November 15 issue of The New England Journal of Medicine, accompanied by an editorial.

The researchers used molecular typing of Borrelia burgdorferi isolates obtained from 17 patients with culture-confirmed episodes of erythema migrans, the characteristic skin rash most closely associated with Lyme disease. In studies of 22 paired episodes of the rash, the data showed that in all cases of recurring infection the next episode was caused by a different strain of Borrelia. In addition, virtually all recurrences occurred one year or more after the first infection, and were observed during the months when nymphal ticks are most abundant; bites from these ticks account for nearly all cases of Lyme infection in the U.S.

“Our findings suggest that recurrences of erythema migrans after standard courses of antibiotic therapy are reinfections rather than relapse,” the authors wrote. “And they provide evidence of the success of antibiotics in eradication of B. burgdorferi” from infected patients.