Measuring, mapping, monitoring and mitigating drivers of the emergence of zoonotic and food-borne diseases: a case study

Over 60% of human diseases originate in animals, many in domestic livestock. Infections that infect both animals and people are called zoonoses, and are caused by different groups of pathogens, including viruses, bacteria and parasites, and are transmitted in many different ways, including through the environment and via contaminated food. As a group, zoonoses are a very significant public health problem, especially in developing countries where this research is focussed. We are particularly interested in understanding what environmental, social, demographic, economic and climate variables come together to cause a pathogen to ?jump? in to the human population from domestic animals (we call these jumps ?disease emergence?). The study will be conducted in Nairobi, the capital of Kenya, because previous work has identified urban and peri-urban (UPU) settings as important places where such a jump can take place, but few studies have examined the particular circumstances of the UPU environment that cause this to happen in any useful detail.

This proposal aims to bring together diverse expertise, to think laterally about the problem of zoonotic and food-borne disease emergence in UPU settings, and to develop new approaches to tackling it. The most important aspect of our approach is the inclusion of a very wide diversity of expertise and backgrounds, covering the breadth of topics that matter in UPU environments. Our aim is to consider the issues, data needs and research opportunities from these different perspectives, supported by extensive analysis of the existing literature and a small pilot data collection exercise. The priorities and approaches that emerge from these activities will form the basis for a further application to gather complete data sets and provide the evidence-base for changes to policy.

We aim to create a multi-disciplinary grouping of researchers, policy makers and other stakeholders to address the issue of the emergence of zoonotic and food-borne diseases in urban and peri-urban (UPU) settings in the developing world. Our focus is on diseases involving livestock reservoirs, using Nairobi, Kenya as a case study. Over 50% of Africa?s population will soon be urbanised, and urban farming and livestock keeping are significant income generators; urbanisation has been identified as one of the main drivers of the emergence of human diseases, though with little specific focus. It has been proposed that the processes leading to the emergence of new diseases are likely to be those that also matter for the re-emergence of endemic zoonotic and food-borne infections. Understanding these as models is a tractable problem; our study will therefore 1) improve our ability to predict the occurrence and burden of new diseases and 2) provide an opportunity to understand the biology and social ecology of existing but neglected zoonoses.

Our project grouping will be made up of epidemiologists, medical practitioners, field and policy veterinarians, public health policy makers, human and livestock demographers, sociologists, economists, specialists in food-borne disease systems, urban planners, climate change experts, geographers, urban waste managers, government officials, human and livestock health extension workers, food trade bodies, NGOs and private sector diagnostics manufacturers. We will consider a broad set of issues, priorities and data needs relating to UPU environments, developing a research strategy that goes beyond the usual speciality-focussed agenda, with the formulation of appropriate mitigation policies in mind.

Our focus will be: 1) measuring drivers of emergence (eg social factors motivating and affecting livestock keeping, movements of people, livestock, current and projected urban planning and sanitation needs; 2) mapping drivers (e.g. urban landcover change, trends in climatic extremes in rural zones and country-scale climate changes, the dynamic patterns of UPU settlement, the distribution of people and livestock); 3) monitoring emergence (e.g. how do people in UPU environments access health care, how are illnesses diagnosed, what is currently known about the human burden of zoonoses in UPU settings, what is the penetration of diagnostic facilities, how does the immuno-compromised UPU population influence emergence?); 4) mitigating against zoonotic and food-borne disease emergence (e.g. community-based strategies, drought relief, regulation).

The project will be delivered through cross-disciplinary discussions and workshops, a small pilot data collection exercise and the writing of a research paper and a report.