Subscribe to the World's Most Popular Newsletter (it's free!)
Ehrlichioses are emerging infections in the United States. Human granulocytic ehrlichiosis (HGE) and
Lyme borreliosis (LB) are acquired after Ixodes ricinus-complex tick bites. An ongoing seroepidemiologic study of the 185 of the 356 permanent residents of the Koster Islands in Sweden was expanded to include ehrlichioses. Ehrlichial antibodies were measured by IFA using Ehrlichia equi and Ehrlichia chaffeensis. Borrelia burgdorferi IgG ELISA-seropositive subjects were confirmed by Western blot. E. equi and E. chaffeensis antibodies (titer > or = 80) were found in 21 (11.4%) and 2 (1.1%) of 185 samples, respectively. Antibodies to B. burgdorferi were found in 25 (13.5%) of 185. Six persons were seropositive for both HGE and LB. Among data from questionnaires, clinical symptoms, antibiotic treatments, or tick bites were not more frequent in E. equi- or B. burgdorferi-seropositive than -seronegative persons. The seroprevalence of HGE was similar to that of
Lyme borreliosis. Prospective studies of European HGE are needed.