[Lyme disease and Borrelia burgdorferi infections in Europe]

Lyme disease is endemic in Europe. The strains of the causative agent, Borrelia burgdorferi, seem to be antigenically more heterogeneous than the North American isolates. The only documented vector for this bacterium in Europe is ixodes ricinus, but other vectors might be involved as observed in the United States. The tick hosts are not yet well documented in Europe. Human infection occurs principally during summer months. The clinical aspect of the disease has particular features in Europe: at the early stage of the disease, a single and large erythema chronicum migrans is observed on the skin; complications often include meningoradiculonevritis (Bannwarth's syndrome) and later, acrodermatitis chronica atrophians; arthritis is less frequent in Europe than in the USA. The culture of B. burgdorferi from the lesions is difficult. The diagnosis of the disease is performed on the basis of serological tests: immunofluorescence assay where the important thing is to define a cutoff titer; ELISA tests using either whole cells or supernatant of sonicated cells or flagellar antigen; passive haemagglutination for IgG; IgM solid phase haemadsorption; Western blot (immunoblot) seems interesting to perform on a research basis to determine to which protein antigens patients are responding with antibody. Once antibody production begins, it is usually in the form of IgM antibody to flagellin protein (41 kD), with time, both IgM and IgG antibodies to a variety of other antigens appear. Prophylaxis is based on health services and public education because a prompt removal of the tick diminishes risk of infection with B. burgdorferi (4 p. cent of cases after tick bite). The treatment includes aminopenicillins or tetracyclines at the early stage. The second and third stages of borreliosis are treated by high doses aminopenicillins or cetriaxone.