Complex Systems Thinking in Health

This chapter introduces the notion of complex systems and discusses how the many ideas surrounding them can be helpful and necessary in One Health. We first give a brief account of the basic phenomena that occur in complex systems, such as feedback loops, chaos, and emergence, and then argue that a complex systems approach is necessary to understand One Health, and is compatible with its aspirations. To illustrate the promise of complex systems ideas applied to One Health problems, we explore two scenarios: prediction of epidemics and the difficulty of implementing change and engineering resilience; and we give concrete ideas from complex systems that could lead to new approaches to disease surveillance and control. We hope that this chapter will leave the reader with an understanding of both the necessity and promise of complex systems thinking in One Health.