Q fever is a widespread zoonosis caused by Coxiella burnetii. In humans, Q fever can manifest as an acute or as a chronic disease. Coxiellosis in domestic animals is usually asymptomatic; however has also been found associated with abortions and stillbirths in sheep and goats. Domestic ruminants are the primary and important reservoirs of Coxiella burnetii, which is exerted in the milk, urine, feces and vaginal mucous of infected animals. Inhalation of bacteria present in the environment is the main route of animal and human infection. The aim of this study is to survey prevalence of Coxiella burnetii and correlation of this organism with host determinants in sheep. Serum samples from 220 ewes were collected randomly in Ahvaz city and were examined by ELISA assay. Seroprevalence of Q fever was 13.18% (95% CI: 8.71-17.65%). Logistic regression showed that the odds of disease was declined with increase of age (OR: 0.73 and 95% CI: 0.46-1.16, P>0.05) and 1.6% of fluctuation of disease was justified by age. Relative frequency of prevalence was higher in Lori than Arabic breed (P>0.05). Greater odds of disease in Lori than Arabic breed was seen (OR: 1.44 and 95% CI: 0.66-3.16, P>0.05) and 0.7% of fluctuation of disease was justified by breed. 51.4% of fluctuation of disease was justified by history of abortion and greater odds of disease in sheep with history of abortion than healthy sheep was seen (OR: 120.56 and 95%CI: 15.88-915.49, P<0.001). Multivariable logistic regression showed that 52% of fluctuation of disease was justified by age, breed and history of abortion. This serosurvey suggests Coxiella burnetii has a significant correlation with abortion. According to local weather conditions and facilitative airborne transmission, prevention and control measures should be considered by health authorities.
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