Sero‐prevalence of brucellosis in cattle in Swaziland

Abstract

This study aimed at establishing the first cross‐sectional sero‐prevalence study of bovine brucellosis in the cattle population in Swaziland as well as technology transfer regarding the ELISA technique to allow an extended serological diagnosis of bovine brucellosis in the country. Twenty diptanks out of 778 functional diptanks were randomly selected for the cross‐sectional brucellosis survey across all the four regions of Swaziland. A total of 1623 bovine sera from individual cattle out of an estimated bovid population of 622 715 was tested for the presence of Brucella antibodies using the Rose Bengal test (RBT) and indirect Enzyme Linked Immunosorbent Assay (iELISA). The iELISA proved to be more sensitive than the RBT, overall. However, in some cases the RBT yielded more positive reactors than the iELISA and vice versa. The serological prevalence of bovine brucellosis at diptank level ranged from 0.0% to as high as 53.3% and 50.9%, as determined by the RBT and iELISA tests, respectively. Regional seroprevalence ranged from 3.05% to 53.05% by RBT and by iELISA, the sero‐prevalence ranged from 3.90% to 52.84% and in both tests Lubombo region had the highest sero‐prevalence and Hhohho region the least. Based on the findings of this study sero‐prevalence of bovine brucellosis across all sampled regions was 16.14% and 17.38% in RBT and iELISA test, respectively. However, to achieve maximum sensitivity in this survey a parallel interpretation of the test results achieved by the two tests was used and an overall sero‐prevalence of 21.50% was established. The western parts of the country exhibited a lower bovine brucellosis seroprevalence, however, a systematic national bovine brucellosis survey is recommended.