Determinants of Brucellosis Seroprevalence in Cattle and Occupationally Exposed Humans in Bauchi State

Brucellosis is a priority zoonotic disease in Nigeria's livestock belt, but the determinants of its occurrence at the human-animal interface are incompletely characterized. This study analyzed the determinants of brucellosis seroprevalence in cattle and occupationally exposed humans in Bauchi State, North East Nigeria. A cross-sectional study was conducted across six local government areas. Blood samples were collected from 250 cattle and 150 humans including herdsmen, slaughterhouse workers, and veterinary personnel. Bovine samples were tested by Rose Bengal Plate Test and confirmed by competitive enzyme-linked immunosorbent assay. Human samples were tested by enzyme-linked immunosorbent assay for anti-Brucella IgG. Multivariable logistic regression was applied to identify determinants. Bovine seroprevalence was 21.2%, and human seroprevalence was 14.7%. Significant risk factors in cattle included herd size above 50 animals, history of abortion, and use of communal water sources. In humans, working as a herdsman, consuming raw milk, and assisting in parturition without protective gear were the strongest predictors. Spatial analysis identified clustering of seropositive cases in three southern local government areas. The study concludes that behavioral and structural risk factors drive brucellosis transmission at the Bauchi human-animal interface. Targeted vaccination of high-risk cattle herds, pasteurization promotion, and training of herdsmen on protective parturition practices are recommended. Keywords: brucellosis, seroprevalence, risk factors, Bauchi State, zoonotic transmission