Studies of the prevalence of Coxiella burnetii, the agent of Q fever, in the foothills of the southern Bavarian Forest, Germany.

In studies carried out in 1991 in the foothills of the southern part of the Bavarian Forest, in the district of Freyung/Grafenau, ticks and small mammals were collected and examined for the presence of Coxiella (C.) burnetii and sera of small mammals and cattle investigated for antibodies against this rickettsia. A total of 1716 imagines and nymphs of Ixodes ricinus were collected by flagging and 892 larvae and nymphs of the same tick species removed from small mammals. In addition to 1095 serum samples from cattle, 326 specimens of nine species of small terrestrian mammals were examined. Neither in ticks nor in rodents, C. burnetii was detected, however, in 17 of 21 localities, seropositive cattle were found. Altogether, 12% of all 1095 heads of cattle tested were seropositive for C. burnetii antibodies. These serological results indicated a wide dissemination of C. burnetii in cattle of the region investigated, but there was no indication of a natural focus. As in other areas of Europe, an independent natural cycle of the agent involving cattle only is assumed to occur in this region.