Seroprevalence and Associated Risk Factors of Brucellosis in Backyard Dairy Cattle in the Western Buffer Zone of Chitwan National Park, Nepal.

Abstract

INTRODUCTION: Brucella abortus, the etiological agent of bovine brucellosis, is a significant zoonotic disease of dairy cattle. The issue is particularly evident in Chitwan, one of the largest milk-producing districts in Nepal. MATERIALS AND METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to detect circulating antibodies against B. abortus in backyard dairy cattle in the western buffer zone of Chitwan National Park, Chitwan, Nepal. RESULTS: A total of 382 cattle, comprising Holstein-Friesian-cross and Jersey-cross breeds, were sampled; 6 were excluded from statistical analysis. Of the remaining 376 cattle, 6 (1.6%; CI: 0.59-3.44) tested positive for B. abortus. After adjusting for test specificity and sensitivity, the prevalence was estimated at 1.56%. No significant associations were found between higher antibody prevalence and risk factors such as sampling location, breeding technique, breed, age, parity, abortion, hygroma, repeat breeding and herd size. However, the presence of wildlife species in the buffer zone and low farmer awareness of zoonoses may contribute to persistent infection risks. CONCLUSION: These findings underscore the presence of bovine brucellosis in a key dairy region of Nepal and highlight the need for further investigation into the disease's epidemiology and its public health significance.