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

Q fever is a worldwide disease which is common between human and livestock. This disease is created by an obligate intracellular Rickettsia called Coxiella burnetii (C. burnetii). Cattle, goats and sheep are among the main reservoirs of the disease in humans. The most common routs of transmitting the infection to humans are inhalation of contaminated aerosols and drinking milk and non-pasteurized dairy products. This study was aimed to determine the prevalence of C. burnetii in non-pasteurized dairy products in Shiraz. In this study (from summer 2016 to winter 2016), 238 non-pasteurized dairy products, (48 raw milk, 48 yogurt, 46 cheeses, 48 dough and 48 ice cream samples) were collected from the retail market and analyzed using a nested PCR assay. This study showed that 20 samples (8.4%) of 238 non-pasteurized dairy products were reported positive for C. burnetii (13 of 48 (27.08%) raw milk, 3 of 48 (6.25%) yogurt, 2 of 46 (4.35%) cheese, 2 of 48 (4.16%) dough and 0 of 48 ice cream samples). The present study suggests that non-pasteurized dairy as 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 human.