[Reinfection with Borrelia burgdorferi in an immunocompetent patient].

A 54-year-old patient with an intact immune system developed Lyme disease three times within 4 years. The first time an erythema migrans occurred, which was successfully treated with oral doxycycline (100 mg twice daily for 20 days). Specific antibodies were subsequently demonstrated. Re-infection nonetheless occurred a year later, again as erythema migrans. Oral doxycycline in higher dosage (three times 100 mg daily for 20 days) failed to prevent generalization of the infection with rigor, head and neck aches, myalgia, fatigue and subfebrile temperatures. There was a marked increase in Borrelia-specific antibody titre. Parenteral treatment with cefotaxime (twice daily 3 g for 12 days) was curative. But 2 years later yet another re-infection occurred with classic erythema migrans, which regressed under doxycycline. The course of the disease in this case demonstrates that Borrelia-specific antibodies do not always protect against re-infection. This may have consequences for the possible development of a vaccine.