This article introduces the concept of One Health, a public health framework adopted by the Centers for Disease Control in 2009, which recognizes the interdependence of humans, animals and our shared environment. The concept has gained traction as a way to address health problems arising from global environmental change.
Climate change, loss of biodiversity, habitat fragmentation and pollution, and subsequent degradation of natural environments threaten the range of ecosystem services that support all life on this planet [Sleeman 2019: 91].
It was the challenge of responding to these complex [environmental] problems that led to the emergence of the concept of One Health, which is defined by the Centers for Disease Control and Prevention (CDC) as the collaborative effort of multiple disciplines and sectors – working locally, nationally, regionally and globally – with the goal of achieving optimal health outcomes, recognizing the interconnection among people, animals, plants and our shared environment. This definition acknowledges that human, domestic animal and wildlife health are interconnected within the context of ecosystem/environmental health and provides a useful conceptual framework for the development of solutions to global health and environmental challenges. Given this interconnection, it follows that actions aimed primarily at improving the health of one part of the human-animal-environmental triad may have unanticipated consequences for the system as a whole if the harms they may cause to the other components are not considered. However, previous authors have noted that, despite the acknowledged interdependencies, few public or livestock health interventions include a consideration of biodiversity conservation or ecosystem/environmental health. Instead, health-promoting interventions focus largely on single-sector outcomes and, thus, may miss the opportunity to concurrently optimize outcomes in the other two sectors [Sleeman 2019: 92].
The authors suggest that despite its potential, the One Health approach does not as yet fully integrate wildlife and environmental health, instead favoring human health. Yet failure to optimize the health of all three realms can lead to unexpected and outcomes, ironically increasing risk to humans in some cases. Therefore, the authors propose the clarification of One Health values and goals, and integration of a systems approach and a harm reduction perspective into the One Health framework.
Systems biology provides methods to understand how interactions among [interrelated and interdependent] parts [livestock, humans and wildlife, for example] give rise to the function and behavior of that system [Sleeman 2019: 96].
A harm reduction perspective recognizes that solutions to complex problems require a broad societal response and that elimination of risk is not feasible for most issues. Consequently, this perspective promotes collaborative, multisectoral approaches whereby reducing harm, despite uncertainty regarding the outcome, is valued over inaction spurred by a desire for a perfect solution [Sleeman 2019: 94].
Sleeman, J.M., et al., 2019, Integration of wildlife and environmental health into a One Health approach, Rev. Sci. Tech. Off. Int. Epiz. 38(1), https://pubmed.ncbi.nlm.nih.gov/31564738/.