Repeat or persistent Lyme disease: persistence, recrudescence or reinfection with Borrelia Burgdorferi?

Whether or not Borrelia burgdorferi can persist after conventional treatment with antimicrobials has been a very controversial issue. Two recent studies took different approaches to try to answer this question. In one, investigators showed that, in each of 22 instances in 17 patients with two consecutive episodes of culture-proved erythema migrans, the strains of B. burgdorferi were different based on their genotypes. This indicated that the repeat episodes were due to new infections rather than recrudescence of the original infection. In another study, in which persistence of B. burgdorferi was assessed by using xenodiagnosis, no viable B. burgdorferi were cultured from ticks fed on any of the patients. There continues to be no evidence that viable B. burgdorferi persist in humans after conventional treatment with antimicrobials.