Risk factors of Q fever in sheep and goat flocks with history of abortion

Abstract

The purpose of this study was to determine the individual- and flock-level risk factors of Q fever in sheep and goat flocks in Iran. A total of 970 sera including 803 ovine and 167 caprine samples from 43 sheep and goat flocks in the Southwest, Central, and Western Iran were collected randomly. A questionnaire was administered to each visited farm to gather information for investigation of suggested risk factors. The CHEKIT Q fever ELISA kit was used to identify specific antibodies against Coxiella burnetii in sheep and goats. The results showed that the flock level prevalence of Q fever was 100 %. Among the studied risk factors, significant association was observed for seropositivity with area, breed, and parity on individual level and presence of ticks on flock level. Central Iran significantly had the highest prevalence followed by Southwest and Western Iran which could be due to favorable climatic conditions for aerosol transmission of C. burnetii in this area. Native breed had the highest prevalence (28.9 %) of Q fever followed by mixed (22.2 %) and Afshari (13.3 %) breed (P < 0.05). Seropositivity increased with parity, and third parity animals had the highest prevalence (29.3 %). There was significant association between presence of tick on the farm with seroprevalence of Q fever; farms with tick contamination had higher prevalence compared to tick-free farms (27.3 vs 20.3 %, respectively, P = 0.04). In conclusion, the present study demonstrated the relatively high prevalence of Q fever in sheep and goat flocks in Iran. Further, the native breed and third parity animals on individual level and presence of tick on flock level are considered the most important risk factors for C. burnetii infection.