Culture-confirmed reinfection of a person with different strains of Borrelia burgdorferi sensu stricto.

In recent years, the utility of serum-based diagnostic testing for Lyme disease has improved substantially; however, recovery by culture of the bacterium from skin biopsies of suspected patients is still the only definitive laboratory test. Reinfection of patients has been assumed to occur but as yet has not been documented by serial isolates from the same person. We present a case of culture-confirmed reinfection of a patient in Menominee County, Michigan. Borrelia burgdorferi was isolated from the skin punch biopsy specimens during each episode of erythema migrans (EM) and was subjected to molecular strain typing, genetic analysis of two outer surface protein genes, protein profile analysis, and serum antibody response testing. Results show that these isolates are distinct strains of the bacterium and that the two episodes of EM were caused by independent infections. This report describes the documented, culture-confirmed reinfection of a human by two different strains of B. burgdorferi.