One Region, One Health: A joint Quadripartite approach to complex health challenges in the Western Pacific

The COVID-19 pandemic demonstrated in no uncertain terms that human health does not exist in a vacuum – it is interlinked with the health of animals and the planet. Activities with high environmental impact – such as deforestation, intensive farming and wildlife trade – can disrupt ecosystems and drive diseases to spill over from animals to people, as seen with dengue, avian influenza and rabies. The situation is alarming. In the past 30 years, 75% of new or emerging human diseases have come from animals, causing over 2.7 million deaths every year.

The emergence and spread of zoonotic diseases is heavily influenced by changing ecosystems impacted by climate change. For example, Pacific island countries and areas have reported the highest number of dengue cases in a decade and this is attributed to shifting weather patterns in the region.

The close links between humans, animals and the environment demand ever greater collaboration, communication and coordination among all relevant sectors. The One Health approach that reflects this convergence enables experts across disciplines to harness collective action, build synergies and collaboratively tackle complex health challenges.

Multisectoral action exemplified through the One Health Quadripartite 

The One Health Quadripartite – comprising the Food and Agriculture Organization of the United Nations (FAO), United Nations Environment Programme (UNEP), World Health Organization (WHO) and World Organisation for Animal Health (WOAH) – exemplifies the One Health approach.

Members of the Quadripartite work cohesively to support One Health-related activities, coordinate inter-agency engagement and promote partnerships that address common challenges. In the Asia Pacific region, the Quadripartite has supported the implementation of National One Health Joint Plans of Action; supported the Association of Southeast Asian Nations (ASEAN) One Health initiative; provided technical and strategic guidance for One Health governance; facilitated National Bridging Workshops; rolled out One Health tools; and advocated for One Health action across the region.

On 12 August 2025, WHO and other Quadripartite members convened more than 140 representatives from across the Western Pacific Region to advance priority actions under One Health, reiterate the role of the Quadripartite and facilitate cross-learning. The Member State briefing was a response to requests received from countries during the side event on One Health held at the seventy-fifth session of the Regional Committee for the Western Pacific in 2024. 

“Our health is inextricably interwoven with the health of the animals we live alongside and the environment we rely on,” said Dr Saia Ma’u Piukala, Regional Director for the Western Pacific, who reiterated the need for multisectoral collaboration. “In the WHO Western Pacific Region, we have prioritized One Health actions – learning the lessons of COVID-19 and other emergencies − and this approach is at the heart of our regional vision and strategy.”

Implementing One Health actions at the national level

During the briefing, representatives from Cambodia, Indonesia and Papua New Guinea shared examples of how they are progressing towards implementing One Health priorities in their respective countries and the role the Quadripartite has played in these achievements.

Cambodia’s IMCC coordinates efforts between animal and human health sectors to enable faster detection and containment, minimizing the spread of the H5N1 virus.

Cambodia: Dr Krang Sidonn, Deputy Director, Communicable Diseases Control Department of the Ministry of Health, described how Cambodia leveraged support from the One Health Quadripartite to develop a national One Health strategy and formalize coordination mechanisms, including an Inter-Ministerial Coordination Committee (IMCC), with the aim to predict, prevent, detect and respond to One Health threats. The IMCC enables coordinated decision-making during any disease outbreak response that requires multisectoral action, including the recent H5N1 (avian influenza) outbreak.