LONG-TERM STUDY OF LYME BORRELIOSIS IN A HIGHLY ENDEMIC AREA IN SWEDEN

From May 1991 to May 1994, Lyme borreliosis was studied prospectively in 301 residents living on Aspo, a highly endemic area for the disease , The study included annual questionnaires and blood samples for serol ogy. Immunoglobulin G (Igg) antibodies to Borrelia burgdorferi sensu l ate were detected by enzyme-linked immunosorbent assay in 63/301 (21%) of the residents at the start of the study, Seropositivity rates incr eased with time, and 3 years later 101/301 (34%) were positive, A tota l of 34 individuals developed physician-verified manifestations of Lym e borreliosis during the study period, Nine individuals developed an e rythema migrans, despite a previously treated Lyme borreliosis or pre- existing high levels of IgG antibodies to B. burgdorferi s.l.