Seroprevalence and Risk Factors for Bovine Brucellosis in Polonnaruwa District, Sri Lanka

Purpose: This study aimed to determine the seroprevalence of bovine brucellosis and identify key risk factors contributing to its transmission in dairy cattle in the Polonnaruwa district, where abortion-related reproductive losses had been reported.Research Method: A cross-sectional study with a two-stage sampling procedure was employed. The blood samples were collected from 180 cattle across 38 farms that had reported abortions between August 2022 and August 2023. Serological testing was done using the Rose Bengal Plate Test (RBPT) and confirmed with the Complement Fixation Test (CFT). A pre-tested structured questionnaire was used to collect data on demographics, management practices, and reproductive history of cattle. Data were analyzed using SPSS (version 25), applying descriptive statistics, chi-square tests, and multivariate logistic regression.Findings and Values: The study reported a high seroprevalence of 35.5% at the animal level and 63.15% at the herd level. Abortion history, poor hygiene, and larger herd size were identified as significant independent predictors of bovine brucellosis seropositivity. Females, crossbreeds, and older animals showed higher seropositivity. The findings suggest that bovine brucellosis may be endemic in the region and underline the potential value of targeted control measures such as improved biosecurity, reproductive screening, and farmer education to help reduce the disease burden and protect both animal and public health.