Seroprevalence of Coxiella burnetii infection in commercial dairy cattle farms in the Emirate of Abu Dhabi, United Arab Emirates

Coxiellosis is a disease of public and animal health significance caused by Coxiella burnetii. In livestock, the disease is associated with abortion, stillbirths, and weak neonates. Recently, C. burnetii-seropositive cattle were detected in the Emirate of Abu Dhabi, UAE (EAD) necessitating further serological assessment across the region. Therefore, this study aimed to assess C. burnetii serostatus in dairy cattle in the EAD. Jugular blood from randomly selected cattle (n = 734) at 11 dairy farms were ELISA-tested for C. burnetii-antibodies, the seroprevalence data compared using a χ² test between different herd sizes, and a spatial GIS seroprevalence map generated. The overall C. burnetii-seroprevalence was 49.0 % (95 % CI: 45.34 % - 52.67 %) with individual farm values ranging from 0.0 % to 70.0 %. The seroprevalence for “small”, “medium”, and “large” herd size farms were 24.0 %, 49.0 % and 52.0 % respectively, while the differences between the “small” and either “medium” (χ² = 11.25; P < 0.0001) or “large” herds (χ² = 19.71; P < 0.0001) were statistically significant. However, the difference between the “medium” and “large” size herds was not significant (χ² = 0.33; P = 0.57). Dairy cattle exposure to C. burnetii appears widespread across the EAD with a presumed infection risk that appears to increase with herd size. These data justify appropriate control and preventive measures to minimize economic and public health impacts of the pathogen in the region and further warrant additional studies for defining the coxiellosis-risk factors unique to the EAD, genotyping local C. burnetii strains, and elucidating public health implications of the disease.