The status of bovine brucellosis in Gauteng Province, South Africa, 2020

Introduction: A population-based survey was carried out to estimate the prevalence of bovine brucellosis in an endemic area (Gauteng Province, South Africa) and to study possible risk factors. Methods: In 2019-2020, 254 herds (9111 cows) were randomly selected, tested serologically and classified as positive/negative using a two-test system. Results: The herd-level (13.6%), individual-level (1.7%) and within-herd (8.9%) prevalence's were estimated. Several risk factors are identified in this population that could help to target disease control – large herds, shared communal grazing land, herds being unvaccinated, and testing with isolation of new cattle before introduction to the herd. Conclusion: Overall, the bovine brucellosis prevalence had not changed in the past four years but it was less than the prevalence within surrounding countries in the region. The reported vaccination coverage had improved since the previous survey but remained inadequate with many owners not knowing the vaccination status of their cattle. We discuss if elimination is possible in this province considering the prevalence level, impending control policy changes and communal farming practices. We describe lessons learned in the field by Provincial Veterinary Services and suggest what is needed for successful control and eventual eradication in this setting.