Brucella melitensis in wildlife in South Africa

Abstract

This thesis offers a comprehensive examination of Brucella melitensis in South African wildlife, with a particular focus on sable antelopes (Hippotragus niger). The research encompasses an extensive review of existing literature and empirical studies, aiming to deepen the understanding of the epidemiology, diagnosis, and management of B. melitensis in wildlife, particularly in the context of the South African wildlife ranching industry. Chapter 1 Summary: "Research Introduction and Literature Review" Chapter 1 of the thesis delves into the research background by outlining the historical outbreaks of B. melitensis in South Africa, tracing its evolution from affecting sheep to goats and, ultimately, humans. A notable outbreak on a farm in the Western Cape is emphasised, illustrating the cross-species transmission potential between livestock and humans. This section also highlights the growing practice of wildlife/game ranching in South Africa, drawing attention to its possible role in spreading zoonotic diseases such as brucellosis. The aim of the research is clearly defined: to investigate, analyse, and describe ongoing outbreaks of B. melitensis in South African wildlife, with a particular focus on the wildlife ranching industry. Objectives are set to include conducting retrospective studies on B. melitensis in sable, adapting diagnostic tests for wildlife, and performing genomic characterisation of the isolates in South Africa. The scope and approach of the research involve studying anonymised cases from wildlife farms and closely examining the role of wildlife/game ranching in rural South Africa, especially focusing on the ranching of sable antelopes. Discussing the interactions between wildlife and livestock and the critical importance of effective disease surveillance in these contexts complements this. The chapter offers an in-depth look at brucellosis, particularly B. melitensis, discussing its pathogenicity, zoonotic potential, clinical signs, diagnostic methods, and control measures in livestock and wildlife. It further explores the challenges of disease spillover to wildlife, transmission mechanisms, and environmental survival, stressing the need for comprehensive control and prevention strategies that consider wildlife's unique biological and ecological aspects. In conclusion, Chapter 1 lays a comprehensive groundwork for the thesis, providing a thorough understanding of the current state of knowledge regarding B. melitensis in wildlife, with an emphasis on the South African context, and frames the research within the broader objectives of wildlife conservation, public health, and the dynamics of zoonotic diseases in an evolving ecological and economic landscape.