One Health is an international movement to promote a holistic multidisciplinary approach at the animal–human–ecosystem interfaces. One health is not a new idea or principle but it is simply recognition of the need to promote a culture of working together in a sustainable way, particularly in resource-constrained countries, to address health risks at the human–animal interface.

The outbreaks of SARS, avian influenza, and Nipah virus in Asian countries clearly demonstrated that new highly infectious and/or highly pathogenic agents periodically emerge at the human–animal interface, and will continue to emerge in the future. The unprecedented outbreaks of these diseases had serious impacts on travel, trade, and tourism, and it was realized that prevention and control of emerging infectious and high impact diseases required a holistic, multidisciplinary approach. The experiences of regional countries with avian influenza and pandemic (H1N1) 2009 have reinforced the need for sustained, well-coordinated, multi-sector, multi-disciplinary, community-based actions to address emerging disease threats that arise at the human–animal interface.

The International Ministerial Conference on Avian and Pandemic Influenza (IMCAPI) held in New Delhi in December 2007 recognized that highly pathogenic avian influenza (HPAI) was deeply entrenched in several countries and the current state of veterinary services and preparedness levels in most countries of Asia and Africa posed a serious threat to the prevention and control of HPAI and other infectious diseases. Thus, the New Delhi conference appealed to the global community to begin to address broader issues around the emergence and spread of HPAI and other emerging infectious diseases through international partnerships (Press Information Bureau of the Government of India 2007). Each Government should encourage functional links between human and animal health systems, while investing in sustainable capacity for preventing and controlling high impact diseases in animals.

The New Delhi Road Map offered a valuable benchmark for the preparedness efforts of national authorities and proposed a convergence between animal and human health systems. The conference also requested international partners to develop a strategic framework for implementation of One Health and present it at the sixth IMCAPI held in Sharm Al Sheikh in October 2008. The Strategic Framework was the joint product of six major international organizations: the Food and Agriculture Organization (FAO), the World Health Organization (WHO), the World Organisation for Animal Health (OIE), the United Nations Children’s Fund (UNICEF), the World Bank, and the United Nations System Influenza Coordination (UNSIC). The strategic framework for reducing risks of infectious diseases at the animal–human–ecosystem interfaces was presented at the ministerial conference. The document sets out six priority objectives for countries to consider, such as developing capacity in surveillance, promoting interagency and cross-sectoral partnerships, and ensuring functioning national emergency response capacity (Contributing to One World 2008). The application of a One Health approach aims not only to minimize the local and global impact of epidemics and pandemics caused by emerging infectious diseases, but also to look at more holistic approaches for solving health-related problems in line with International Health Regulations (2005).

The seventh International Ministerial Conference on Animal and Pandemic Influenza held in Hanoi in April 2010 reiterated the need to move forward the one health approach at country level (http://​www.​imcapi-hanoi-2010.​org/​home/​en/​). The scope, priority, and approaches may be different in public health and animal health institutions and therefore it will be necessary to promote integrated and/or coordinated approaches for the implementation of ‘One Health’. It was recognized that animal health sector is weak in terms of surveillance and response for emerging and high impact diseases and therefore more investment will be required for strengthening animal health services in developing countries. Indeed, the veterinary public health service is rudimentary in most developing countries and it is estimated that USD 1.3 billion will be required annually to implement a One Health approach until 2020 (http://​siteresources.​worldbank.​org/​EXTAVIANFLU/​Resources/​3124440-1172616490974/​Fifth_​Global_​Progress_​Report_​July_​2010.​pdf). The technical discussions held for operationalizing One Health, from ideas to action in Winnipeg (2009) and Stone Mountain (2010), have encouraged academics, donors, and partners to synthesize concrete action points for pushing ‘One Health’ movement to a higher level. A high level technical meeting, jointly organized by FAO, OIE, and WHO, was held in Cancun in November 2011 to address health risks at human–animal–ecosystem interfaces, and identified key elements, high priority technical actions, and related practical next steps for moving forward on intersectoral collaboration, coordination, and communication (World Bank 2010).

One Health activity is a spontaneous movement—there is no consensus on definition of One Health, and even at the One Health Conference held at Melbourne in 2011, no clear definition was apparent. While the general concepts are now well accepted, how to implement the One Health concept is still not clearly understood (http://​www.​who.​int/​influenza/​human_​animal_​interface/​HLTM_​human_​animal_​ecosystems_​nov_​ 2011). Each stakeholder understands it in a different way, and there is a lack of coordination and collaboration among them. A number of international donors and partners are involved in promoting the One Health concept through pilot projects in Asian countries and it has definitely contributed to advocating a One Health approach among intellectuals and professional groups but it has not yet generated a political commitment or the involvement of the government sector.