Brucellosis and its associated risk factors to humans and domestic ruminants in Kagera Ecosystem, Tanzania

BACKGROUND: Brucellosis is an important disease for both veterinary and public health. A study was conducted to understand the seroprevalence of brucellosis and its associated risk factors in pastoral areas of Kagera, Tanzania. METHODS: Sera from 156 patients with malaria-like symptoms were analyzed using the commercial rapid agglutination test (specific for B.abortus and B.melitensis detection) and Fluorescence Polarization Assay (FPA). Sera from 426 cattle, 206 goats and 197 sheep were analyzed using Rose Bengal Plate (RBPT) and Competitive ELISA (c-ELISA) tests. RESULTS: In humans, overall brucellosis, B. abortus, and B. melitensis sero-prevalences were 7.7% (95%CI: 3.8–12.2%), 1.9% (95% CI: 0.4–4.5%), and 5.8 % (95%CI: 2.6–10.6%), respectively. At animal level, seropositivity was 5.9% (95%CI: 4.0–8.6%), 2.5% (95%CI: 0.8–5.7%) and 0.5% (95%CI: 0.01–2.8%) in cattle, goats and sheep, respectively. At herd level, seropositivity was 18.2% (95%CI: 12.0–25.8%) in cattle and 6.9% (95%CI: 2.2–15.3%) in small ruminants. Brucellosis was associated with assisting in parturition without wearing protective gears (OR= 5.6; p= 0.02) in humans, herds of 50–200 animals (OR= 4.2, p= 0.01) and cattle (OR=3.5; p=0.01). The knowledge of brucellosis among pastoralists (OR=0.1; p<0.01) was a protective factor. CONCLUSION: Brucella infections could be occurring in pastoralists and domestic ruminants in Kagera. Community health education is necessary for the control of brucellosis in Tanzania.