Identification of Coxiella burnetii in Raw Milk of Livestock Animal in Iran

Coxiella burnetii is the causative agent of Q fever in humans and animals. This study aimed to determine the frequency of C. burnetii in milk samples of dairy animals (goats, sheep, and cattle) in some selected regions in Iran, where there is no information about prevalence of C. burnetii. In this study, 162 individual milk samples were collected from 43 farms in three provinces (Tehran, Hamadan, and Mazandaran). Real-time PCR was used for the detection of IS1111a element of C. burnetii. In total, 23 of 162 samples (14.2%, 95% confidence interval (CI): 9.65-20.2%) were positive for C. burnetii by real-time PCR. C. burnetii was detected in 10.17% (95% CI: 4.74-20.46) of goat milk samples. In sheep milk samples, 18.6% (95% CI: 9.74-32.62) were positive, and C. burnetii was detected in 15% (95% CI: 8.1-26.11) of cattle milk samples. Molecular evidence of the presence of C. burnetii was seen in milk samples of dairy animals in all the studied regions. These findings demonstrated that C. burnetii infection, especially in raw milk samples, deserves more attention from the health care system and veterinary organization in Iran.