The intensification of livestock production and its impact on zoonotic disease risk

In the past 20 years, 177 different human diseases have appeared for the first time or re-emerged as threats to health. Of these, 73% are zoonotic, that is diseases which have moved from animal hosts to human hosts. Many of these have done so via livestock (pig, chicken, cattle) production and distribution ? examples include SARS, bird and swine flu. These diseases are significant in both animal production systems, where they limit productivity and capacity to export, and of course in human health, but researchers in animal and human disease systems do not work together on these. Nor is there significant cooperation between government agricultural and health departments in monitoring zoonotic diseases emerging in animal production and moving into human populations.
Without such collaboration, we will not understand the conditions that cause zoonotic pathogens to arise in (or move through) animal production systems into human populations and spread there. We suspect the factors that cause this to happen are complex. Some are biological and ecological, such as contact of livestock with disease wildlife, while others are economic, such as the rapid growth in livestock production and movement.
We will bring together researchers on zoonotic diseases from across the animal-human health sector divide, and from different disciplines ? biology, economics, sociology, etc. We will focus our work on Asia, where zoonotic diseases are appearing most regularly and spreading to the rest of the world. We will engage zoonotic disease researchers from across East and Southeast Asia, who are currently collaborating with the UK groups leading this project.
Through shared papers and workshops, participants will first frame questions to ask about how zoonotic disease emerge, and then design short research projects to gather data for analysis. From this analysis, they will develop a conceptual model for how these different factors affect zoonotic disease emergence. This will lead to a research proposal to test the project?s hypothesis that changing animal production is increasing disease risk. It will also produce a publication, to guide other researchers in taking inter-disciplinary and inter-sectoral approaches to zoonotic disease. This publication will reach Asian and African collaborators involved in the project, so that they may use it to help build their own national zoonotic research projects in a way that best supports development of cross-cutting solutions across sectors and informs decision makers in government.

The emergence of global zoonotic disease threats in human populations has been closely associated with the movement of diseases through animal production systems and into human populations where they spread. Animal production systems are changing at an unprecedented rate, particularly in Asia, the epicentre of the livestock revolution. Understanding the relationship between animal production and zoonotic disease outbreaks in human populations has been constrained by lack of collaboration between public health and veterinary research communities, and lack of coordination in disease surveillance, regulation and policy between the livestock industry and the public health sector. An inter-sectoral, inter-disciplinary research approach is needed.
Our research hypothesis is that the rapidly changing nature of the production and movement of livestock and livestock products will increase the risk of zoonotic diseases emergence and of pandemics in human populations. To address this hypothesis, we bring together experts in zoonotic disease research from animal and human health sectors, and across disciplines, ranging from molecular epidemiology to the political economy of infectious disease policy. This collaboration builds on an initial inter-disciplinary activity, started in 2008. The focus will be on Asian systems. Outputs will be a focused research proposal and a peer-reviewed publication presenting results and proposing new approaches for inter-disciplinary zoonotic disease research.
The team of investigators will comprise disciplinary groups working across sectors on biological-environmental, economic-political and social-historical aspects of zoonotic disease emergence. A first workshop will build understanding and respect for different approaches to the core hypothesis, and develop research plans. Research will characterize systems of zoonotic disease ?incubation? and spread in Asia and focus on specific case studies. A second workshop will use these to generate a conceptual model for how natural and social science-related drivers affect disease emergence A third workshop will finalize preparation of a research proposal and a publication. We will base the project in both Thailand and UK, engaging zoonotic disease research networks in Asia and (through south-south links) in Africa.
While the direct output of the project will be a research proposal for UK Research Councils, broad engagement of researchers in key regions of zoonotic disease origin will ensure that outputs stimulate research proposals to other regional and international sponsors. Collaborating regional networks have particularly strong links with government and civil society stakeholders, which will facilitate engagement and dissemination of findings, as will our publication.