Pilot serosurvey of Coxiella burnetii in domesticated small ruminants in the United Arab Emirates.

The seroprevalence of Coxiella burnetii in goats and sheep in the UAE was evaluated by ELISA testing of 437 small ruminant sera samples from livestock farms (LivF) and 478 from the Al Ain livestock market (AALM), and the data from the pilot serosurvey were analyzed using the z-test of two proportions and Fisher's method. The overall proportion of C. burnetii-seropositive goats of 32.1% was significantly higher than 24.7% for seropositive sheep (p < 0.05). On the other hand, the difference in the proportions of C. burnetii-seropositive sheep from the LivF (27.9%) and AALM (21.7%) was not statistically significant (p > 0.05). By comparison, the proportion of C. burnetii-seropositive goats from LivFs was 31.6% compared to 32.5% for the goats from the AALM (p > 0.05). In addition, there was variability in the proportions of C. burnetii-seropositive goats and sheep from the different Emirates, but none of differences was statistically significant (p > 0.05). These data provide the first evidence of apparent C. burnetii infections in goat and sheep herds in the UAE with seropositivity rate that is significantly higher in goats than sheep. The epidemiology and animal and public health implications of this pathogen need to be thoroughly evaluated in the UAE.

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.

Serological evidence of enzootic bovine leukosis in the periurban dairy cattle production system of Al Ain, United Arab Emirates.

The serostatus of enzootic bovine leukosis (EBL) was determined at three dairy farms and the Al Ain Livestock Market (AALM), within the Al Ain region of Abu Dhabi, UAE. Of the 957 bovine sera tested by ELISA, 657 were from Holstein-Friesians from three dairy farms, and 300 from Bos indicus cattle at AALM. The chi-square homogeneity test (CSHT) and the Marascuilo multiple comparison procedure (MMCP) assessed the level of significance between the proportions of EBL-seropositive cattle (ESPC) across the study farms and AALM, and between the age groups at farms 1 and 3. Overall, the proportion of ESPC was 25.7% at dairy farms and AALM, 37.0% for farms and 1.0% for AALM. Furthermore, the proportions of ESPC at farms 1, 2 and 3 were 54.7%, 0.0% and 26.3% respectively, and statistically significant differences were seen across the farm/farm and farm/AALM comparisons, and between two age groups at farms 1 and 3. The 37-72-month-old age group showed the highest proportion of ESPC. This is the first serological evidence of EBL in the UAE. As previously reported, the ESPC are comparatively higher in dairy than Bos indicus cattle. Molecular and more extensive serological studies are needed to further corroborate the present data. Meanwhile, the UAE veterinary authorities will need to formulate national EBL control policies.