Biological diagnosis of human Borrelia burgdorferi infections

Lyme borreliosis is the most frequent human tick-borne disease. Since culture of Borrelia burgdorferi from human samples is rarely successful, biological diagnosis currently rely on serology mainly. Lyme serology is usually performed using ELISA tests and confirmed by Western-blot analysis, but many aspects of this latter method need to be standardized between clinical microbiological laboratories. Serological diagnosis of B. burgdorferi infections is impaired by the existence of cross-reactions, by antigenic diversity among european strains and by the high seroprevalence in endemic areas. For these reasons, results have to be always interpretated together with the clinical data. Utilisation of recombinants antigens has been proposed for Lyme serology but, up to now, results are not fully satisfactory. From several years, PCR has been proposed for detection of B. burgdorferi in human samples. Beside the usual restrictions that need to be evoked before utilisation of this kind of assay in routine analysis, it is clear that prospective studies need to performed to precise the usefulness of PCR for the different manifestations of the disease.