Cultivation of Borrelia burgdorferi from human tick bite sites: a guide to the risk of infection.

Abstract

The risk of acquiring Lyme disease has been evaluated by xenodiagnostic procedures with laboratory strains of Borrelia burgdorferi and laboratory-reared Ixodes ticks, or by clinical trials in which diagnosis was based on clinical findings, culture, or serologic tests. Our purpose was to determine the risk of infection from tick bites in a natural setting in which wild strains of B. burgdorferi were involved, by a biopsy culture technique. Skin biopsy specimens were obtained from Ixodes scapularis tick bite sites, processed, and examined for the presence of B. burgdorferi. B. burgdorferi was cultivated from only 2 of 48 skin biopsy specimens. In both instances duration of tick attachment was approximately 24 hours. In a hyperendemic region for Lyme disease the risk of infection after a deer tick bite appears to be low, particularly if the tick has been attached for less than 24 hours.