Evidence of Rickettsia spp. infection in Sweden: a clinical, ultrastructural and serological study
Sweden is an area potentially endemic for spotted fever rickettsioses. Rickettsia helvetica has been isolated from its tick vector Ixodes ricinus, and in a handful of cases linked to human disease. This study demonstrates for the first time in Sweden the transmission of rickettsial infection after a tick bite and the attack rate in an endemic area. We present three cases of documented rickettsial infection and a prospective serological study of Swedish recruits who were trained in the area where the patients lived and showed seroconversion to spotted fever rickettsiae. All patients showed a four-fold increase in antibody titer to the spotted fever rickettsia, R. helvetica, and immunohistochemical examination revealed rickettsia-like organisms in the walls of skin capillaries and veins. Electron microscopy showed organisms resembling R. helvetica and immunogold labeling with two anti-rickettsial antibodies demonstrated specific labeling of the rickettsial organisms in the skin biopsy specimens. Eight of the thirty-five recruits showed a four-fold increase in IgG titer reflecting a high rate of exposure. The results of this study demonstrate that spotted fever rickettsioses should be taken into consideration in the diagnosis of tick-transmitted infections in Sweden.
Document Type: Research Article
Affiliations: 1: Unit of Pathology, Department of Genetics and Pathology, and 2: Department of Biology and Chemical Engineering, Mälardalens University, Eskilstuna, 3: Department of Pathology, WHO Collaborating Center for Tropical Diseases, University of Texas Medical Branch, Texas, USA 4: Gotland Coast Artillery Regiment, Fårösund, 5: Unit of Forensic Medicine, Department of Surgical Sciences, Uppsala University Hospital, Uppsala,
Publication date: 2005-02-01