Multispecies Q Fever Outbreak in a Mixed Dairy Goat and Cattle Farm Based on a New Bovine-Associated Genotype of <i>Coxiella burnetii</i>

A Q fever outbreak on a dairy goat and cattle farm was investigated with regard to the One Health concept. Serum samples and vaginal swabs from goats with different reproductive statuses were collected. Cows, cats, and a dog were investigated with the same sample matrix. The farmer’s family was examined by serum samples. Ruminant sera were analyzed with two phase-specific enzyme-linked immunoassays (ELISAs). Dominant immunoglobulin G (IgG) phase II levels reflected current infections in goats. The cows had high IgG phase I and II levels indicating ongoing infections. Feline, canine, and human sera tested positive by indirect fluorescent antibody test (IFAT). Animal vaginal swabs were analyzed by qPCR to detect <i>C. burnetii</i>, and almost all tested positive. A new cattle-associated <i>C. burnetii</i> genotype C16 was identified by the Multiple-Locus Variable-number tandem repeat Analysis (MLVA/VNTR) from ruminant samples. Additionally, a possible influence of 17ß-estradiol on <i>C. burnetii</i> antibody response was evaluated in goat sera. Goats in early/mid-pregnancy had significantly lower levels of phase-specific IgGs and 17ß-estradiol than goats in late pregnancy. We conclude that the cattle herd may have transmitted <i>C. burnetii</i> to the pregnant goat herd, resulting in a Q fever outbreak with one acute human case. The influence of placentation and maternal pregnancy hormones during pregnancy on the immune response is discussed.