Epidemiologic Investigation of Acute Q Fever in North of Iran

Q fever is a worldwide zoonosis which is an endemic in many regions. Its diagnosis is usually missed especially in human. This research aimed at investigating acute Q fever among suspected patients in northern Iran. This cross-sectional study was conducted in 56 suspected cases of Q fever selected from 476 febrile patients admitted in Qaemshahr Razi Hospital, Iran 2016, with systemic or respiratory symptoms.  Blood samples and sera were tested for detection of IgG phase II antibodies against C. burnetii by quantitative ELISA. Seroconversion and/or four-fold rise in IgG phase II titers were the diagnostic criteria of acute Q fever infection. The prevalence of acute Q fever was 5.37% (95% CI: 1.84, 14.61%). Risk factors for Q fever infection included living close to livestock farms and consumption of unpasteurized milk or dairy products. However, these risk factors were not significantly different between patients with Q fever and seronegative cases of Q fever (P<0.612).  In current study, 23.21% of the participants were found with a history of Q fever infection. Acute Q fever was diagnosed in many cases in north of Iran indicating a high prevalence of the disease. Therefore, Q fever serology must be checked in seronegative suspected brucellosis.