The collaborative work of the Food and Agriculture Organization of the United Nations (FAO), the United Nations Environment Programme (UNEP), the World Health Organization (WHO) and the World Organisation for Animal Health (WOAH – founded as OIE) to address risks at the human-animal-ecosystems interface was formally laid down in 2010 in the FAO/OIE/WHO Tripartite Concept Note and is being increasingly recognized by the global community.

In accordance with the governance of the organisations concerned, the executive level of the Tripartite is the respective Directors General or their designated Deputy or Assistant Directors General of the FAO and WHO and WOAH, who meet in person at least once annually, and by teleconference as necessary, to discuss and reach consensus on strategic issues.

At the 28^th Tripartite Executive Annual Meeting, the Directors General of FAO, WHO and WOAH, and the Executive Director of the United Nations Environment Programme (UNEP), signed a Memorandum of Understanding for collaborative One Health work, renaming the group the “Quadripartite,” reflecting equal participation of all four partners. The rotating “Tripartite Secretariat” was transformed to “Quadripartite Secretariat” in response to an executive-level desire to ensure a structured and robust follow-up of the decisions taken, to maintain the annual Quadripartite Executive Meeting at the highest strategic level and to delegate non-executive level strategic and technical issues to a Secretariat.

The mandate of the Secretariat is to ensure, between executive-level meetings, a direct line of communication among the four agencies, to inclusively and consistently address technical and policy issues of mutual concern throughout the year and take appropriate decisions, in support of the collective executive level direction.