Genotyping of Coxiella burnetii strains detected in cattle from a nationwide survey in Korea.

A total of 123 strains detected in cattle from a nationwide survey in Korea were classified into the genomic groups I (0.8%), II (13.8%), III (11.5%), IV (63.1%), and V (5.4%). Acute Q-fever strain (groups I, II, and III) was 27.6%, and chronic strain (groups IV and V) was 72.4% of the total. A dairy farm, both types were detected, showed 6.7 times higher detection rate than another farm where only chronic Q-fever strains were detected. Both acute and chronic Q-fever strains are widespread in Korea, and it could represent an active transmission source to livestock and humans.