Seroprevalence and Associated Risk Factors of Bovine Brucellosis in Cattle in Tabora Region, Tanzania

Abstract

Bovine brucellosis is a zoonotic disease that causes substantial economic losses in livestock production and poses a serious public health threat. Assessing its prevalence and associated risk factors is critical for designing effective control strategies in Tanzania. A retrospective study was conducted in the Tabora region using 618 archived cattle serum samples collected from eight district councils. Initial screening for brucellosis was performed using the Rose Bengal Test (RBT) followed by confirmation using Fluorescence Polarization Assay (FPA). Data on cattle characteristics including district of origin, breed, age, sex, and farming system were retrieved and analyzed. Chi-square tests and odds ratios were used to quantify strength of associations between potential risk factors and the seropositivity, with a significance level of p<0.05. The overall apparent seroprevalence of bovine brucellosis based on FPA was 5.1% (95% CI= 3.5 – 7.1, 31/618). The highest seroprevalence was observed in Uyui district (8.2%; 95% CI= 2.7 – 18.1) while the lowest was in Nzega DC (3.0%; CI=0.6 – 8.4). There was no significant statistical association between risk factors (age, breed, farming system and district) and seroprevalence. Agreement assessment between RBT and FPA assays yielded Kappa = 0.907, indicating a very good agreement. The findings confirm that Brucella spp. is endemic, circulating at relatively low levels among cattle herds across all districts of the Tabora region. The absence of significant associations with specific risk factors suggests that control strategies should adopt a holistic approach, addressing multiple dimensions of infection. Recommended measures include testing and culling of reactors, farmer education, vaccination, and improved livestock husbandry practices, particularly through the implementation of biosecurity measures