Understanding and managing zoonotic risk in the new livestock industries

Background: In many parts of the world, livestock production is undergoing a process of rapid intensification. The health implications of this development are uncertain. Intensification creates cheaper products, allowing more people to access animal-based foods. However, some practices associated with intensification may contribute to zoonotic disease emergence and spread, for example the sustained use of antibiotics, concentration of animals in confined units, and long distance and frequent movement of livestock. Objectives: This paper reviews the diverse range of ecological, biological, and socio-economic factors likely to enhance or reduce zoonotic risk, and identifies why improved understanding requires an interdisciplinary approach. A conceptual framework is then offered to guide systematic research on this problem. Discussion: We recommend that interdisciplinary work on zoonotic risk should be able to account for the complexity of risk environments, rather than simple linear causal relations between risk drivers and disease emergence and/or spread. Further, we recommend that interdisciplinary integration is needed at different levels of analysis, from the study of risk environments to the identification of policy options for risk management. Conclusion: Given rapid changes in livestock production systems in developing countries and their potential health implications at the local and global level, the problem we analyse here is of great importance for environmental health and development. While we offer a systematic interdisciplinary approach to understand and address these implications, we recognise that further research is needed to clarify methodological and practical questions arising from the integration of the natural and social sciences.