Seroprevalence of Coxiella burnetii in a dairy cattle herd from the Al Ain region, United Arab Emirates.

The present study assessed the serostatus of Coxiella burnetii in a dairy cattle herd from the Al Ain region, UAE. In addition, the study evaluated the relationship between C. burnetii seropositivity and history of abortion and cattle age. Blood/sera from 759 cattle were tested by ELISA, and the data analyzed by the Pearson Chi-square test (PCST), odds ratios, and logistic regression. Of the 759 study cattle, 36.5% (277/759) were seropositive while 63.5% (482/759) were seronegative for C. burnetii. Additionally, 19.5% (148/759) of the cattle had ever aborted while 80.5% (611/759) had not. Meanwhile, 34.3% (95/277) of the C. burnetii-seropositive cattle (CBSPos) had history of abortion while 65.7% (182/277) did not. By comparison, only 11.0% (53/482) of the C. burnetii-seronegative (CBSNeg) cattle had history of abortion while 89.0% (429/482) had never aborted. The difference in the conditional probabilities of CBSPos or CBSNeg cattle that had history of abortion was statistically significant (PCST; p value 0.001), as was the association between a CBSPos outcome and history of abortion (p value 0.0001). Moreover, the odds of prior abortion having occurred in CBSPos were 4.3 times higher than in CBSNeg cattle. Similarly, the log of the odds of past abortions was positively correlated with C. burnetii seropositivity and cattle age (p value < 0.001). These data demonstrate apparent C. burnetii infections in cattle from the UAE in which the risk of abortion appears to increase with cattle age. Molecular testing for C. burnetii and comprehensive investigations of other abortigenic pathogens in the study cattle herd are recommended.