One Health – towards a more inclusive science
In 1997, Marcel Tanner, the then director of the Swiss Tropical and Public Health Institute (Swiss TPH) asked me whether, as a veterinarian, I could take a look at the health care of mobile pastoralists (nomadic and transhumant livestock keepers) and their animals in Chad. This mostly nomadic population group falls through the mesh of the Chadian health care system and is completely undersupplied. On this occasion, I remembered my doctoral supervisor Hans Fey, a professor of microbiology at the University of Bern's Faculty of Veterinary Medicine, in Switzerland, who introduced me to the term “One Medicine”. Coined in the 1960s by American epidemiologist Calvin Schwabe, it says that there is no paradigmatic difference between human and veterinary medicine and that both share the same scientific principles.
From “One Medicine” to “One Health”
In 1998, as part of a project supported by the Swiss National Science Foundation, an interdisciplinary team of human and veterinary medical staff started to investigate the health of people and their animals on the south-eastern shore of Lake Chad. To our surprise, we found that more animals than children were vaccinated. In a participatory transdisciplinary process with representatives from the population, authorities and science, we agreed on the implementation of common vaccination campaigns for humans and animals. When the veterinarians started organising vaccination campaigns for animals, they took human medical staff with them in the same vehicle. While the vets vaccinated cows, the health workers vaccinated children and women and provided people with medicines and conducted health training, giving a population group previously excluded from care access to health services. The shared use of the cold chain and transport also saved time and money compared to separate services.
This work was the starting point for our theoretical and methodological development from “One Medicine” to “One Health”, with a stronger emphasis on public health and disease prevention. One Health promotes cooperation between representatives from science, authorities and the population. This increased communication helps not only to gain a deeper understanding of the situation, but also to develop better solutions that are supported by all stakeholders and can therefore have a lasting effect. “One Health” therefore means an added value for the health of people and animals and is attractive for health authorities thanks to the financial savings in healing and disease control costs. This is achieved through closer, interdisciplinary and transdisciplinary cooperation on a par between human and veterinary medicine, other natural sciences and the humanities.
Efficient, cost-saving and universally applicable
How can the added value of closer cooperation between human and veterinary medicine be shown? With statistical methods, we can demonstrate that with an interdisciplinary approach, the source of zoonoses (diseases that are transmitted from animals to humans) can be found much more quickly than when humans or animals are examined on their own. Using mathematical models and economic analyses, we see that zoonoses such as brucellosis and rabies can be controlled and eventually eliminated at lesser cost if we contain them in reservoir animals instead of just treating affected people. The joint investigation of schistosomiasis in humans and cows in Côte d’Ivoire showed us a previously neglected high proportion of hybrid forms between animal (Schistosoma bovis) and human (Schistosoma haematobium) parasites in humans. This demonstrates how a zoonosis can develop with unrestricted contact between humans and animals.
One Health approaches are not limited to infectious diseases, but can also be used in many other contexts, for example in rehabilitation therapy. Together with psychologists, we developed and examined animal-assisted therapies for patients with brain injuries, in which the well-being of the animals used is just as important as that of humans. In cooperation wit