One Health is an integrated and holistic approach to address health threats at the animal-human-environmental interface. It aims to sustainably balance and optimize the health of people, animals and ecosystems. By promoting coordination and communication across multiple sectors a One Health approach can achieve better public health outcomes.
One Health recognizes that the health of humans, domestic and wild animals, plants, and the wider environment (including ecosystems) are closely linked and interdependent. Through the linking of humans, animals and the environment, One Health can help to address the full spectrum of disease control – from prevention to detection, preparedness, response and management – and contribute to global health security.
In September 2021, the Directing Council of the Pan American Health Organization (PAHO) endorsed the policy, One health: a comprehensive approach for addressing health threats at the human-animal-environment interface (CD59/9), that calls for a comprehensive and inclusive approach for the Organization to work with its Member States.
PAHO’s Regional One Health approach is built on six interdependent action tracks that require close collaboration across sectors, stakeholders, and countries. The areas of work include:
- Enhancing One Health capacities to strengthen health systems
- Reducing the risks from emerging and re-emerging zoonotic epidemics and pandemics
- Controlling and eliminating endemic zoonotic, neglected tropical and vector-borne diseases
- Strengthening the assessment, management and communication of food safety risks
- Curbing the silent pandemic of Antimicrobial Resistance
- Integrating the Environment into One Health.
WHO is a member of the One Health Quadripartite along with the Food and Agriculture Organization, World Organization for Animal Health and United Nations Environment Programme. The four organizations work together to promote multisectoral responses to public health threats originating in the animal-human-environment interface and to provide technical advice on how to reduce these risks.
At the 28th Tripartite Executive Annual Meeting (TEAM28) in March 2022, a Memorandum of Understanding was signed by the principals of the four organizations, expanding the Tripartite to form the Quadripartite, with the inclusion of the United Nations Environment Programme (UNEP).
 Based on the six action tracks of the Quadripartite OH Joint Action Plan.