Lyme disease (Lyme borreliosis).

Lyme borreliosis (Lyme disease) is a systemic infectious disease with a wide spectrum of symptoms affecting the skin, the heart, and the nervous and musculoskeletal systems. Lyme borreliosis is caused by the spirochaete Borrelia burgdorferi and transmitted by ticks. The disease occurs in endemic pockets with an incidence of from 50 to more than 100 cases per 100,000 inhabitants. Despite increasing knowledge about the virulence factors of the spirochaetes and the immune response of the host, many aspects of the pathogenesis, for example of chronic treatment-resistant disease, are still a matter of debate. The diagnosis is based on clinical findings and confirmed by serology. Diagnostic problems arise from patients with non-specific symptoms and a positive IgG serology. In about 80% of the patients, the disease can be cured by adequate antibiotic therapy. Evidence-based guidelines for treatment have been recently published. The only vaccine to prevent Lyme disease, licensed in the USA, has been discontinued due to disappointing sales despite good efficacy and tolerability.