Prevalence of Coxiella burnetii in unpasteurized dairy products using nested PCR assay

Background and Objectives: Q fever is a worldwide disease which is common between humans and livestock. This disease is created by an obligate intracellular Rickettsia called Coxiella burnetii (C. burnetii). The aim of this study was to determine the prevalence of C. burnetii in unpasteurized dairy products in Shiraz. Materials and Methods: In this study (from summer 2016 to winter 2016), 238 non-pasteurized dairy products, (48 raw milk, 48 yogurt, 46 cheese, 48 dough and 48 ice cream samples) were collected from the retail market and analyzed using a nested PCR assay. Results: This study showed that 20 samples (8.4%), out of the 238 unpasteurized dairy products, were positive for C. burnetii as follows: 13 out of 48 (27.08%) raw milk, 3 out of 48 (6.25%) yogurt, 2 out of 46 (4.35%) cheese, 2 out of 48 (4.16%) dough, and 0 out of 48 ice cream samples. Conclusion: The present study suggests that unpasteurized dairy products are the main sources of C. burnetii in Shiraz, Southern Iran; thus, the consumption of pasteurized milk and dairy products is a valuable method to prevent the disease in humans.