Seroprevalence and Risk Factors for Q fever ( Coxiella burnetii) Exposure in Smallholder Dairy Cattle in Tanzania.

Q fever is a zoonotic disease, resulting from infection with Coxiella burnetii . Infection in cattle can cause abortion and infertility, however, there is little epidemiological information regarding the disease in dairy cattle in Tanzania. Between July 2019 and October 2020, a serosurvey was conducted in six high dairy producing regions of Tanzania. Cattle sera were tested for antibodies to C. burnetii using an indirect enzyme-linked immunosorbent assay. A mixed effect logistic regression model identified risk factors associated with C. burnetii seropositivity. A total of 79 out of 2049 dairy cattle tested positive with an overall seroprevalence of 3.9% (95% CI 3.06-4.78) across the six regions with the highest seroprevalence in Tanga region (8.21%, 95% CI 6.0-10.89). Risk factors associated with seropositivity included: extensive feeding management (OR 2.77, 95% CI 1.25-3.77), and low precipitation below 1000 mm (OR 2.76, 95% 1.37-7.21). The disease seroprevalence is relatively low in the high dairy cattle producing regions of Tanzania. Due to the zoonotic potential of the disease, future efforts should employ a "One Health" approach to understand the epidemiology, and for interdisciplinary control to reduce the impacts on animal and human health.