Studying Tuberculosis in African Lions – Fellowship Training Grant

SUMMARY: Researchers will develop in-field methods and criteria to identify African lions with tuberculosis to guide disease mitigation efforts.  

THE PROBLEM: Mycobacterium bovis (M. bovis) is the causative agent of animal tuberculosis (animal TB). This severe and chronic disease affects wildlife, livestock and domestic animals with potential transmission to humans. Although the typical route of M. bovis infection is inhaling infectious aerosol droplets, it can also occur by ingesting contaminated food, including milk water, grazing pastures, or consuming infected prey. Unfortunately, animal TB affects many of South Africa’s most iconic wildlife species, including African lions, and therefore threatens ecotourism and conservation programs. Previous studies have shown that the African lion population in Kruger National Park, South Africa, experiences a high TB prevalence. Therefore, a better understanding of transmission and disease progression in infected lions will provide the information needed to evaluate the impact of animal TB on KNP lion population dynamics and health.  

THE PROJECT: Researchers will study lions in Kruger National Park, South Africa, which are endemic to M. bovis. Over the next two years, we will perform serial diagnostic testing to evaluate temporal changes in infection status and disease development. We will achieve this through physical examination, radiographs, and ultrasound, while newly developed blood tests will assess immunological responses. Lions' infectiousness will be determined using the direct detection of M. bovis in respiratory samples. The incidence and prevalence of M. bovis infection and TB disease will also be estimated.  

POTENTIAL IMPACT: Accurate detection of M. bovis infection, disease, and especially infectiousness will improve our understanding of the rate at which lions become infected, the duration of infection before developing disease, and whether some infected lions remain asymptomatically infected or even clear infection. This information is crucial for informing long-term conservation strategies for lion populations and provides a foundation for assessing other threats that may impact this species, such as ecosystem changes.  

Importantly, practical, accurate tools for screening lions are also needed to minimize the risk of spread during animal translocation between fragmented populations, a crucial component of conservation programs in South Africa and globally. Overall, the knowledge generated by this study will benefit the management and conservation of other wildlife populations where M. bovis infection may be a threat.