Introduction and Objectives: Zoonosis is one of the most important public health issues. Q fever is a worldwide zoonotic disease caused by an obligatorily intracellular bacterium, Coxiella burnetii. Cows, sheep and goats considered as the main source for human infection. Infected animals shed a large numbers of bacteria in urine, feces, milk, placenta, and amniotic fluid. Humans become infected mainly by inhalation of contaminated aerosols containing C. burnetii shed by infected animals or by eating raw milk and fresh dairy products. Also C. burnetii was classified as a potential bioterrorism agent by CDC. In humans, fever is often asymptomatic, but acute illness is a selflimiting flu-like illness associated with pneumonia, hepatitis and chronic illness with symptoms of chronic fatigue syndrome and endocarditis. Materials and Methods: The main objective of current study was to detect C. burnetii in the bulk milk of industrial dairy farms in Hamadan province, west of Iran by molecular technique. Result: Out of 125 samples that were assayed for detection of C. burnetii by Trans PCR method, C. burnetii were detected from 9 milk samples (7.2%), of which 9.64% of milk samples were in hot and dry seasons and 2.38% of milk samples in wet and cold seasons. Conclusion: The results of this study indicated that C. burnetii as a causative agent of Q fever present in the milk of industrial dairy farms in Hamadan province and have a relatively significant prevalence and requires strategy to prevent human prevalence.
