The current coronavirus pandemic has refocused attention on the fact that more than two thirds of known infectious diseases in humans originated in animals. The majority of infectious diseases that have emerged in recent years were transmitted from wild animals or farm livestock to humans.
In response to this problem, the One Health approach has been developed over the course of the last decade. It is an holistic, interdisciplinary approach that works on local, regional, national and global levels to protect human health considering animal health and environmental health. The aim of this approach is “optimal health and well-being outcomes recognizing the interconnections between people, animals, plants and their shared environment” (One Health Commission, 2020).
Epidemics and pandemics caused by previously unknown zoonotic pathogens have been occurring in humans with increasing regularity over the last few decades (see illustration). Combating these incidences of zoonosis is costly and often only possible on a global level. At the same time, the increasing resistance of pathogenic bacteria against antibiotics poses a further threat to human and animal health as well as (the species community of) the environment. This can be attributed to a considerable extent to the excessive use of these active substances in human and veterinary medicine.
New zoonotic agents often originate in wild animals. They become dangerous to humans when an infection gets spatially and mechanistically possible and can be spread easily across a wide area. The ever-closer proximity between people and wild animals caused by habitat reduction brought about by deforestation, global trade and travel increases the probability of a zoonosis being transmitted to humans. Linking the One Health approach closer with knowledge about the state of biodiversity and quality of the environment is gaining importance in science, politics and society. Therefore, within the framework of the One Health approach a stronger cooperation with the policies of ecology, conservation and sustainable use of biodiversity, and climate change will discernibly take on ever greater importance in the future.
Against this backdrop, we (Ulrike Doyle, Patrick Schröder, Jens Schönfeld, and Kathi Westphal-Settele) believe it will be advisable to incorporate scientific fields such as biodiversity and ecology, as well as environmental administration on a national and international level, into the One Health approach. The Planetary Health approach, for example, looks at the health of humans and animals in a "healthy" environment on a planet-wide scale. A similarly ecologically-oriented One Health approach might involve:
- minimising the likelihood of transmission of zoonoses to humans by implementing preventative conservation measures,
- decreasing the probability of epidemics and pandemics through preventive monitoring of the natural environment and within trade chains,
- reducing the socioeconomic costs of epidemics and pandemics,
- identifying synergies and ensuring consistency between political programmes aimed at health, conservation and climate objectives.
A One Health approach shaped to a large extent by environmental aspects may furthermore be critical in achieving many of the objectives of the 2030 Agenda for Sustainable Development set out by the United Nations (17 Sustainable Development Goals) and thereby substantially strengthen this Agenda.