Epidemiology of brucellosis in smallholder dairy cattle in Hai and Meru Districts, Northern Tanzania

Abstract

Brucellosis is an endemic zoonotic disease in most developing countries caused by a facultative intracellular gram-negative bacterium of the genus Brucella. Brucellosis is one of the six priority zoonotic diseases in Tanzania with high social economic effects. A recently upsurge of brucellosis cases under the smallholder dairy cattle farming in many urban areas in Tanzania is a public health concern. A cross sectional study was conducted between January and June 2022 to establish the seroprevalence of brucellosis and possible risk factors in smallholder dairy cattle farming in the Hai and Meru Districts. To determine the seroprevalence, blood samples were analyzed for Brucella circulating antibodies using the Rose Bengal Plate Test and Competitive Enzyme Linked Immuno-Sorbent Assay. A structured questionnaire was presented to 200 smallholder dairy cattle farmers to explore the potential risk factors associated with brucellosis among dairy cattle in the study area. A total of 400 cattle were blood sampled from 10 villages in each district. The overall seroprevalence of bovine brucellosis was 0.50% and 0% for the Hai and Meru districts, respectively. Analysis of knowledge and management practices of brucellosis in the study areas showed that the majority of farmers (74.5%) knew the disease name; though, majority of them (87.9%) were not aware of the disease clinical signs. The indoor farming system mostly practiced in Hai and Meru District could have contributed to the observed low seroprevalence; thus, brucellosis free certification scheme can be implemented for continuous management of brucellosis in animals and humans as recommended by FAO.