Chris Walzer – Wildlife conservation society, Evolution of the One Health concept
Furthermore, the relationship between humans and plants, including their medicinal value, has a rich history across diverse civilizations and cultures. It is symbolized in arts and literature and recognised in early pharmacognostic works like “De Materia Medica” by Dioscorides.
Hippocrates, often hailed as the “Father of Medicine,” greatly influenced the field of biomedicine and the understanding of socio-ecological health interdependencies. Born around 460 BCE, he was among the first to assert that diseases were natural occurrences, not punishments the gods inflicted.
Hippocrates’ observations led him to understand the impact of the environment on health, an idea encapsulated in his work “On Airs, Waters, and Places”. In this text, he suggested that environmental factors – including climate, water quality, and lifestyle – had a significant influence on the health of individuals and could explain the prevalence of certain diseases in different regions, a groundbreaking concept during a time when supernatural explanations for illness were common.
Furthermore, Hippocrates’ detailed studies on animal anatomy and diseases laid the foundation for comparative medicine. He noticed similarities between human and animal bodies, leading him to believe that understanding animal biology could provide insights into human health.
With the beginning of the early Age of Enlightenment, several advancements in veterinary and human health laid the groundwork for the One Health concept we recognise today. Key figures such as Italian physician Giovanni Lancisi, who studied the role of the environment in disease transmission among animals and humans, and French veterinary surgeon Claude Bourgelat, who established the world’s first veterinary faculty, made significant contributions to this field. Rudolf Virchow, a German physician, played an instrumental role in shaping the principles of One Health. He coined the term “zoonosis,” which refers to diseases that can be transmitted from animals to humans or vice versa.
Virchow’s assertion that there should be no scientific barrier between veterinary and human medicine highlights the interconnectedness of all health domains, a core tenet of One Health.
Canadian physician William Osler, regarded as the father of veterinary pathology in North America, significantly contributed to understanding the connections between human and veterinary medicine, trained with renowned professionals like Dr. Virchow, and educated both medical and veterinary students at McGill University on the relationship between animals and humans. In 1947, James H. Steele, a Doctor of Veterinary Medicine and Master of Public Health, established the Veterinary Public Health Division at the CDC. Dr. Steele recognised animals’ crucial role in the epidemiology of zoonotic diseases, understanding that maintaining animal health is vital for ensuring public health.
Calvin Schwabe, a significant contributor to veterinary epidemiology, coined the term “One Medicine” and called for collaboration between the medical and veterinary professions, laying the groundwork for the integrated approach and crosssector collaboration that characterizes One Health today. His “One Medicine” concept emphasises the interdependence of human, animal, and environmental health.
In 1949, “A Sand County Almanac” by Aldo Leopold and “Silent Spring” by Rachel Carson in 1962 shaped the One Health approach by advocating for the preservation of ecosystems and highlighting the interconnectedness of human and environmental health. Leopold, regarded as the father of wildlife ecology, advocated for respecting and preserving ecosystems. His work focused on the moral responsibility towards the natural world, influencing how we approach the sustainable use of terrestrial ecosystems. On the other hand, Carson’s “Silent Spring” was a call to action against the indiscriminate use of pesticides, highlighting the interconnectedness of human and environmental health. These works, amongst many others, subsequently have influenced our perception of sustainable land use and chemical risks to health, emphasising the importance of understanding the interconnection between humans, animals, plants, and the environment.
In 2003, the head of WCS’s Field Veterinary Program, William Karesh, stated in an interview with the Washington Post that “Human or livestock or wildlife health can’t be discussed in isolation anymore.” “There is just one health. And the solutions require everyone working together on all the different levels.” Subsequently, The Wildlife Conservation Society unveiled the 12 Manhattan Principles on September 29, 2004, during a symposium at Rockefeller University in New York City. Titled “Building Interdisciplinary Bridges to Health in a ‘Globalised World’,” the symposium gathered human and animal health experts who discussed disease transmission among humans, domestic animals, and wildlife, setting twelve priorities to address these health threats. These priorities, termed the “Manhattan Principles,” advocated for a global, interdisciplinary strategy to prevent disease, laying the foundation for the “One Health, One World” concept.
In 2007, the One Health Approach was recommended for pandemic preparedness at the International Ministerial Conference on Avian and Pandemic Influenza in India, while the American Medical Association passed a resolution promoting increased collaboration between human and veterinary medical communities. At the 2008 International Ministerial Conference on Avian and Pandemic Influenza in Egypt, One Health became a political reality as representatives from over 120 countries endorsed a new strategy framed as “Contributing to One World, One Health” to combat avian influenza and other infectious diseases by focusing on areas where animals, humans, and ecosystems interact. Following the conference’s recommendations, major organisations, including FAO, WOAH, WHO, UNICEF, the World Bank, and UNSIC, collaborated to develop a strategic framework that applies the One Health concept to emerging infectious diseases at the animal-human-ecosystem interface, drawing lessons from the H5N1 avian influenza response in the early 2000s. In August 2010, the European Union confirmed its commitment to the One Health approach, emphasising the need for practical policies and strategies that promote interagency and cross-sectoral collaboration. The United Nations and the World Bank further endorsed this approach in July 2010, advising countries to build One Health capacity to respond to various disease threats rather than focusing solely on emergency initiatives for controlling avian influenza. In May 2010, a meeting hosted by the CDC in collaboration with WOAH, FAO, and WHO identified clear actions to operationalise the One Health concept, moving from vision to implementation.
In 2019, the Manhattan Principles were revised and expanded by the Berlin Principles as One Health initiatives and networks increased around the world, and the World Bank endorsed the economic value of One Health. One Health has also been institutionalized at various levels of academia and government, including through the 2010 agreement between the Food and Agriculture Organisation of the United Nations (FAO), the World Organisation for Animal Health (WOAH), and the World Health Organisation (WHO) to collaborate more closely at the human-animal-environment interface. This tripartite agreement evolved into a quadripartite partnership in 2022, following the incorporation of the United Nations Environment Programme (UNEP). In conjunction, the One Health High-Level Expert Panel was founded.
Simultaneously, in early 2021, the “One Sustainable Health Forum”, a cross-disciplinary network of experts collaborating through six permanent working groups, was launched to move beyond the universal health coverage agenda to emphasise the crucial role of health in achieving the Sustainable Development Goals (SDGs) while promoting a balanced synergy between them.
While One Health has traditionally focused on zoonotic diseases, it has evolved significantly to include a broad spectrum of health and sustainability concerns such as biodiversity, climate stabilization, and food and water security.
However, there’s a need to integrate more social sciences and humanities, understand socio-ecological drivers of Health, and prioritise community participation. Furthermore, recent work highlights the importance of including non-western worldviews and multi-epistemic approaches in One Health scholarship. Indigenous knowledge is increasingly recognised for its value in One Health, with calls for partnerships that include Indigenous Peoples. Amongst others, Two-Eyed Seeing enhances Developmental Origins of Health and Disease studies by integrating the best of Indigenous and Western knowledge systems, fostering culturally relevant and collaborative research for the benefit of all. Despite representing less than 5% of the global population, Indigenous Peoples have sustained 80% of the world’s biodiversity on their lands, primarily attributed to their harmonious socio-ecological interrelations, conservation values, and environmental stewardship, the importance of epistemological pluralism in decolonizing global health and advancing One Health.
