Abstract
This PhD research project analysed the infection dynamics in a multi-host epidemiological system at the interface between wildlife, livestock and human populations, in protected areas of Zimbabwe. The growing human pressures in the Anthropocene Era, such as intensive agriculture, exploitation of natural resources and climate change, promote interactions among these three groups. At the wildlife-human interface, this creates a favourable context for the circulation and emergence of pathogens, underlining the need of an integrated approach to understand these complex dynamics. Moreover, the interfaces between wildlife, livestock and humans are often located in rural areas with poor sanitary facilities and represent critical points for examining interspecies transmission mechanisms.The main objective of this PhD research project was to study the factors that influence the circulation of the foot-and-mouth disease virus at these interfaces. This pathogen causes a disease with potentially disastrous economic consequences, but its epidemiology is poorly documented, in particular in LMICs (Low-, -Middle Income Countries). Through three case studies, this project evaluated the epidemiological roles within the domestic animal and wildlife compartments.The first part of this research project analysed epidemiological data on cattle and goats collected in several villages close to protected areas. Through a 1-year longitudinal serological monitoring, a clear positive relationship between the distance from protected areas and the extent of exposure to the foot-andmouth disease virus in cattle could be established. This analysis also identified individual factors, such as species, age and sex, that explain the cattle exposure to the virus through the farmers' practices.The second part was based on the non-invasive ecological (using camera traps) and epidemiological monitoring of wildlife for 1 year. This allowed determining the different epidemiological roles of wild species in the circulation of the foot-and-mouth disease virus by recording contacts between populations and collecting faecal samples at watering points. Impalas and elephants stood out for their prolonged use of water spouts and their centrality in contact networks.Lastly, the third, exploratory analysis relied on the livestock farmers’ participation in monitoring wildlife in areas where the deployment of other methods was limited. By combining this monitoring of wildlife at watering holes with serological data from the cattle brought by these farmers to the same water points, this analysis tried to provide a more detailed definition of the contacts at risk of transmitting the footand-mouth disease virus to cattle. This study was also an opportunity to examine the processes underlying the link between biodiversity and pathogen circulation.The results of this research project underline the importance of integrated management strategies that take into account the health, ecological and social dimensions of wildlife-human interface zones. They also underline the need of closer collaboration between public health, wildlife conservation and livestock farming stakeholders to understand and control the epidemiological risks in vulnerable areas.This thesis offers a significant contribution to understanding the multitude of epidemiological roles in the multi-host system of the foot-and-mouth disease virus in a context where the few studies on this pathogen rarely covered wildlife and more widely the remote areas of Southern Africa. By suggesting ways of improving the management of multi-host interfaces within the framework of sustainable development, it opens prospects for policies that are better adapted to local realities. This might improve the coexistence between humans and wildlife at the interface between protected areas and anthropized areas.