Designing agricultural landscapes to limit zoonotic disease risk in The Gambia

In a rapidly changing world, the spread of diseases from wildlife to humans (zoonotic transmission) is becoming an key part of global health. This is particularly important within the context of human-induced land use change and climate change, which continually have a negative impact on environments and socio-economic status. This in turn can force agricultural practices to adapt or change in response, creating a dynamic setting for zoonotic transmission pathways.

In The Gambia, agroforestry, the practice of agriculture incorporating tree cultivation and conservation is being used to relieve tension between unilateral food production and nature conservation practices, and synergise their endeavours. Nevertheless, an unintended consequence of this could be increased proximity of livestock and humans to carriers of disease (i.e., vectors), resulting in cross-contamination and increased numbers of zoonotic disease cases. Agriculture for food production and security, nature conservation for climate restoration and diseases prevention and control for a healthy population are three key pillars of a thriving society. Moving towards the "pareto optimum" of these pillars must be a goal for one health researchers.

The drivers of zoonoses and the variety of agricultural practices existing are complex, and understanding their interaction requires a holistic approach which can be achieved by fostering a culture of collaboration, multi-, trans-, and inter-disciplinary work. Through a combination of quantitative and qualitative methods, a body of evidence will be amassed that provides an understanding how zoonotic disease transmission occurs across agricultural landscapes, in line with the strategy and core skills advocated by UK Research and Innovation. Translation of this evidence will be necessary, for 1) its dissemination and interpretation to policy makers to create evidence-based policy; and 2) its use in user-friendly tools that will increase awareness in agriculturalists themselves; without their appreciation of the importance of healthy landscapes for healthy lives, long-term, sustainable change will not be achieved.

To begin contextualising the zoonotic and agricultural landscape of The Gambia, a review of the literature will be performed to collate the evidence documenting The Gambia's agricultural practices and their evolution as well as cases of zoonotic disease. Similarly, a review of the available genome sequences of zoonotic pathogens will allow The Gambia's zoonotic landscape to start being quantified. Gaps in these data will be filled through primary data collection taking place across two landscape types: agricultural and seminatural. Samples will be collected and sequenced from small bodied wild animals, domestic animals, and humans and for a group of high-risk pathogens identified, bioinformatic and molecular epidemiological approaches will be used to create contact networks of all local actors involved in transmission. Participatory modelling and ethnographic methods will be employed to better understand how humans interact with the network. With the support of leading experts in systems biology and modelling, a socio-ecological modelling approach will predict zoonotic risks across the two landscapes and in theoretical future scenarios, with the aim of informing outbreak preparedness and mitigation strategies.