language (lingua franca) should be used carefully.
In rural population groups in Chad, new conceptualisations of “access to health care” and “socially layered resilience” by medical anthropologist Brigit Obrist were groundbreaking in gaining a better systemic understanding of the barriers to the implementation of health interventions. We elaborated these approaches into mixed quantitative-qualitative methods which showed that health interventions in different countries must be adapted to local ways of living and thinking in order to be effective – not the other way around. Generally speaking, these experiences have taught us how a more integrative science creates a gain in knowledge that could not be generated without cooperation.
Involving the population and authorities
In all of our One Health projects, we maintain intensive partnerships with local research institutes and universities in accordance with the guidelines of the Commission for Research Partnerships with Developing Countries (KFPE) of the Swiss Academy of Natural Sciences. The development of health care cannot be limited to the academic field, but must include the population and authorities in the co-production of implementation knowledge. Although many participants in such processes have no formal training, they are nonetheless experts who bring knowledge that is often hidden from purely academic approaches. In this way, in iterative, participatory stakeholder meetings, we can develop effective health care in a very targeted manner which is feasible for the authorities and acceptable to the population (also see articles "Adopting the One Health approach in international practice" and "Towards better livelihoods of livestock-keeping communities").
Moving towards a modern theory of health
Although more integrating and systemic approaches to health have emerged recently, we are observing an accelerated fragmentation of human and veterinary medicine into a growing number of sub-disciplines, which repeatedly leads to misinterpretations. The exponentially growing specialist literature cannot possibly be surveyed by individuals.
At the same time, we are observing, especially using the example of COVID-19, how complex the relationships and dependencies between people, animals and the environment are. How can we move in the direction of a modern theory of health suited to face the new complex challenges of global change? Health must be viewed as the sphere of influence of human actions within human-environment systems or ecosystems approaches to health. We also speak of “health in social-ecological systems” (see Box below).
Health concepts at a glance
One Health is, in the first place, at the intersection of human and animal health, aiming to demonstrate a benefit from a closer cooperation of human and veterinary medicine. Clearly, large sections of separated human and animal health do not require a One Health approach. Broader approaches, considering interactions of health and the environment, within social-ecological systems (SES) comprehend One Health, which is thus embedded within ecosystem approaches to health (EcoHealth), for which a newer term, “Health in Social-Ecological Systems” (HSES), has been coined. SES are most often delimited by a given context of a country or a region. One Health includes social and environmental (ecological) factors, reaching beyond the strict limits of public and animal health.
Planetary Health conceptual thinking aims to identify co-benefits across targets, but remains centred on human health and does not explicitly include animal health. Planetary Health can be seen as a historical extension from global health and international health. It attempts to demonstrate linkages of global environmental change and health, which are hard to prove, based on the inherent data variability, confounding factors, and the duration and scale of the phenomena. We argue that One Health should still be at the centre of interest, building inter-sectoral cooperation from the inside and gradually expanding it to more complex issues and health security