One Medicine, One Health, One World

The origin of the One Medicine concept has been linked to the 19th century German physician and pathologist, Rudolf Virchow, whose discoveries on Trichinella spiralis in pork led to valuable public health measures (1). Virchow coined the term “zoonosis” and proclaimed that there should be no dividing line between human and animal medicine. The One Medicine theme was continued by Canadian physician and pathologist Sir William Osler who taught medical students at McGill College and veterinary students at the Montreal Veterinary College in the 1870s (2). Osler published on the relation of animals to man and promoted comparative pathology and the One Medicine Concept.

Public health veterinarians were the next to advance the One Medicine approach. Foremost among these was James Steele who founded the Veterinary Public Health division at the Communicable Diseases Center (CDC) in the USA in 1947 (3). Concentrating on zoonotic disease such as bovine tuberculosis, brucellosis, rabies, and salmonellosis, the organization applied public health principles to prevention and eradication. Almost 20 years later Calvin Schwabe made major advances in the field of public health through his writings and his position as chair of a new Department of Epidemiology and Preventive Medicine at the University of California, Davis School of Veterinary Medicine. He is credited with having coined the term “One Medicine” and he strongly advocated for collaboration between professionals in human and veterinary public health to address zoonotic disease concerns. The One Medicine term has evolved into One Health, placing emphasis on health promotion rather than treating diseases. A further evolution has seen association with an ecosystem health perspective, which recognizes that environmental factors need to be included in consideration of human and animal health and that the inter-relationships among humans, animals, and the environment are critical to health.

In recent years One Health has gathered momentum. The One Health Initiative (4), founded in 2006, is doing an outstanding job of promoting One Health through education and advocacy in the United States and internationally. The organization was co-founded by a physician and a veterinarian and its Board has approximately equal numbers of physicians and veterinarians. It is supported by prominent veterinary and medical organizations and by hundreds of individuals worldwide. The goal of this initiative is to promote application of a cross-sectoral, multidisciplinary approach to mitigate existing or potential risks to health that arise from the interactions of humans, animals and the environment. They are achieving their purpose through “education of international multidisciplinary scientific communities, political and governmental leaders, the general public, and news media about the One Health concept and helping to promote the One Health concept’s expeditious implementation worldwide.” This initiative promotes many activities including the One Health Newsletter published by the University of Florida, which seeks to encourage communication and collaboration among veterinarians, physicians, public health professionals and environmental scientists and to find multi-disciplinary solutions to these shared challenges. Veterinarians continue to play a leading role in support of One Health and a veterinarian was recently appointed as Head of the CDC One Health Office.

Recent outbreaks of zoonotic diseases such as SARS and ebola virus infection, as well as the threat of pandemic influenza served to highlight the significance of One Health and an ecosystem approach in a global context. Much progress is being made at the level of research groups, governments, and public health organizations. However, we can do more at local levels to enhance physician/veterinarian communication and collaboration in dealing with exchange of information and education about zoonoses and other public health issues. Canadian veterinary schools have been leaders in promoting understanding of an ecosystem approach in veterinary medicine to better equip veterinarians to be a part of the transdisciplinary teams concerned with health and are urged to do more (5). We can also do more at a national level to strengthen the capacity of the veterinary profession to provide leadership in public policy as suggested in 2014 by Nielsen et al (6).