Antibodies against Rickettsia spp. in Hunters, Germany

Clinical and microbiological follow-up of an outbreak of Yersinia Pseudo-tuberculosis serotype 1b. Scand J Infect Dis.logical features of Yersinia infection in a territory with developed agricultural production. A widespread outbreak of Yersinia pseudotuber-culosis O:3 infection from iceberg lettuce. outbreak of gastrointestinal illness and erythema nodosum from grated carrots contaminated with Yers-inia pseudotuberculosis. To the Editor: A number of emerging Rickettsia species have been recently described (1). One of these, R. helvetica, was fi rst isolated in Swit-zerland in 1979 and was implicated in perimyocarditis and nonspecifi c febrile disease in humans (2–5). PCR showed its prevalence in 1,187 Ixodes ricinus ticks in southern Germany to be 8.9% (6). This fi nding raises the question whether autochthonous transmission of rickettsiae to humans may occur in Germany. To help answer this question, we conducted a cross-sectional study of the presence of antibodies against Rickettsia spp. in a population in Germany presumably exposed to ticks. On February 4–5, 2006, we used convenience sampling to enroll 286 hunters at a national hunting fair in Dortmund, Germany. All study participants gave written, informed consent. The Ethics Committee of the Charité approved the study. Every participant completed a standardized questionnaire. Serum samples were collected from all hunters and analyzed by immunofl uores-cence assay for 9 Rickettsia species and R. typhi) as described previously (7). Odds ratios (ORs) and 95% con-fi dence intervals (CIs) were calculated by using SPSS software version 14). We considered p<0.05 to be signifi cant. Of the 286 hunters, 252 (88.1%) were male; median age was 46 years (range 17–79 years). Positive antibody titers (immunoglobulin [Ig] G, IgM, or both) against any Rickettsia spp. were found for 26 (9.1%) hunters (95% CI 6.2–13.0). Antibodies against different Rickettsia spp. were found for 18 hunters ; species-specifi c antibodies against R. helvetica were found for 2 hunters and against R. aeschlimannii for 6 (Table). Seropositive and seronegative hunters did not differ signifi cantly with respect to sex, age, and total years of hunting. Neither hunting nor traveling in a foreign country within the past 5 years was signifi cantly associated with seropositivity. Neither of the 2 hunters with R. helvetica–specifi c antibody titers had traveled outside Germany in the 5 years before the study, but 3 of the 6 hunters with specifi c titers against R. aeschlimannii had traveled and hunted in countries with unknown endemicity for R. aeschlimannii (Rus-sia, Romania, Namibia). A total of …