Objective: To study the prevalence and the clinical features of Lyme arthritis in a Swedish area highly endemic for Lyme borreliosis.
Methods: Sera from 480 of 540 individuals living in a tick endemic area on an island in southern Sweden were tested by ELISA for IgG antibodies against Borrelia burgdorferi. A questionnaire was completed at the time serum was obtained. Antibody positive individuals who reported joint pain were examined by the authors one year later.
Results: Of 90 seropositive individuals, 34 (38%) reported symptoms of chronic or recurrent arthralgia. Of seronegative individuals from the same area 48/390 (12%) reported such complaints (p < 0.001). One year later one of the 34 seropositive patients with arthralgia had died and, of the remaining, 32 still had arthralgia. Lyme arthritis was diagnosed in 11/32 (35%) of these individuals corresponding to a prevalence of 2.3% (95% confidence interval: 1.0-3.6) in the population. The prevalence of other rheumatic disorders did not differ from that found in other areas in South Sweden. Clinical and laboratory findings were in agreement with previous reports of Lyme arthritis. Other manifestations of Lyme borreliosis were found in 6 of the 11 patients with Lyme arthritis. After antibiotic treatment 9/11 (82%) remain free of complaints followed for 6 months or more.
Conclusion: Our results indicate that arthritis and musculoskeletal symptoms of Lyme borreliosis are as common in highly endemic areas for Lyme borreliosis in Sweden as in similar areas in North America.