Coxiella burnetii and coinfections in Ixodes ricinus ticks in Central Germany.

A total of 1000 Ixodes ricinus ticks were collected in 2006 and 2007 in a forest region of Central Germany and investigated for Coxiella burnetii. The transposase element IS1111 and isocitrate dehydrogenase gene were targets of the real-time polymerase chain reaction. The pathogen was detected in 19 ticks (1.9%), and interestingly, in 10 of these samples, coinfections with Borrelia spp., spotted fever group rickettsiae, or Babesia spp. were present. Our study reports on C. burnetii infections in I. ricinus ticks in an area where cases of Q fever occur regularly and Dermacentor marginatus is not present. The broad spectrum of copathogens indicates interactions in transmission cycles and the possibility of coinfections in humans in areas where people are in close contact with infected ticks and domestic animals.