LYME BORRELIOSIS - A TICK-BORNE SPIROCHETAL DISEASE

The spirochaete Borrelia burgdorferi (sensu lato) is the cause of Lyme borreliosis, a common tick-borne disease with a wide geographical dis tribution. B. burgdorferi s.l. was first isolated in 1982 after a clin ical and epidemiological study of an unusual outbreak of arthritis in children in the town of Old Lyme, Connecticut, USA. Despite this recen t discovery, there is evidence that Lyme borreliosis has existed for m any years. Clinical manifestations are diverse, but antibiotic therapy is largely successful when initiated early in the disease. Molecular- based studies have improved the laboratory diagnosis of Lyme borrelios is and played a significant role in ecological and taxonomic investiga tions of the pathogen. B. burgdorferi s.l. is now divided into some ni ne genospecies and genomic groups, some of which have been associated with particular manifestations of disease, while the number of tick sp ecies found to be competent vectors has also increased. The emerging e cology of B. burgdorferi s.l. is more complex than originally describe d and, consequently, the assessment of risk of disease to an individua l bitten by a tick should include establishing the identity of the tic k, duration of attachment and degree of engorgement, as well as consid eration of the individual's way of life and environment. (C) 1998 Chap man & Hall.