[How widespread is Q fever in Switzerland?]

There are very few reports in the literature on mass seroepidemiological studies of the prevalence of Q fever antibodies. Those to be found are mostly concerned with focal epidemics of Q fever. Out of more than 2000 serum specimens from blood donors analyzed at random in Switzerland in 1982 for Q fever antibodies, 3.5% gave seropositive results (CBR titer at least 1:10). In selected population samples, e.g. forestry workers or vets, the prevalence was distinctly higher (7.6% and 25.7%). Contact with sheep and the consumption of unboiled and not commercially processed milk proved to be mutually independent risk factors. The foregoing findings indicate that the incidence of Q fever in Switzerland is higher than would appear from the number of cases reported to the Federal Health Department. They are discussed in view of the recent renewed interest in Q fever endocarditis.