One Health

One Health is in the title of this book. But just like the other concepts of health described above, there is no single, universally recognized definition of the term (see Table 1.2). One Health, as it is commonly used today, was initially conceived by the Wildlife Conservation Society as an integrated, holistic, and preventative approach to diseases at the human-animal-environment interface. What started as a plan to reduce overexploitation of wildlife became a framework for collaboration to combat emerging infectious diseases. One Health grew to focus on improving or supporting multidisciplinary communication and collaboration with a major goal of addressing key public health outcomes of integrated disease prevention and surveillance, food safety, and food security. This characterization of One Health overlaps significantly with the scope of practice of veterinary public health. As enthusiasm grew, One Health began to further expand its scope of practice to a wider array of health issues for people and animals (Table 2.3) (Oura et al., 2017). In 2010, the World Animal Health Organization (OIE) noted the importance of со-managing the relationships between animal production systems, human influence on the environment, climate change, and emerging diseases. This paralleled the concept of healthy public policy that recognizes that health promotion goes beyond health care and therefore, health is a team activity


Three Emphases of One Health




Connecting diseases across species

Emerging zoonotic diseases in people emerging from animal sources lead to efforts at preventing these diseases at their animal origins

Early efforts focused on building new capacity to find bacteria and viruses that could jump between species. Efforts to control infectious diseases of animal origin inspired reinvestment in veterinary public health around the world

Moving beyond infections

Getting rid of the age-old zoonotic and livestock diseases was recognized as a critical component of poverty reduction and food security

Eliminating livestock diseases to produce more affordable and available food to combat food insecurity and malnutrition. Sustaining wildlife populations to maintain ecological sendees and protect traditional uses of wildlife by indigenous populations

Building resilience

Global megatrends like climate change, urbanization, globalization, and landscape alterations concurrently threatening people, animals, and environments

One Health ideas were extended to protect animal and environmental health as a moral good and for long-term human benefit

rather than the purview of any one agency or discipline (see Chapter 10 for more on healthy public policy).

The One Health emphasis on multi- and interdisciplinary approaches extended veterinary public health from its emphasis on biomedical interventions targeting single hazards to a team approach that examines multiple dimensions of a shared problem. This in turn opened lines of investigation and action derived from the socio-ecological model of health. Although public health concerns predominate One Health activities, the idea that there are reciprocal relationships between people, animals, and their shared environment affecting animal health outcomes is not lost. One Health initiatives are increasingly aiming for mutual benefits for people, agriculture, and wildlife. Some One Health activities are starting to focus on human and environmental determinants of fish and wildlife health in recognition that the survival and persistence of wild animals is entirely dependent on how we decide to exploit their populations and compete for the services provided by their habitats. Attention to the human dimensions of conservation is needed to produce robust and effective conservation policies, actions, and outcomes (Bennett et al„ 2017). One Health is increasingly recognizing that when health is the subject of interest, the social dimensions of human-animal interactions are important (Wolf. 2015).

The lack of a single definition of health, or of One Health, provides a flexibility to work across perspectives, species, and disciplines but can complicate program evaluation or implementation due to a lack of shared vision of success. It can also lead to unanticipated effects. For example, culling rats in Vancouver, Canada, to reduce some zoonotic disease and mental health risks from a burgeoning rat population unexpectedly or even paradoxically increased the prevalence of one zoonotic pathogen while decreasing another (Lee et al., 2018). Similarly, culling bats in Uganda to remove a host of Marburg virus may have eliminated immediate human exposure risk but subsequently increased risk as bats that repopulated the area had a higher seroprevalence of the virus, likely due to the recolonizing bat's naive immunological status (Amman et al., 2014).

One Health is not without critics. Protecting and improving access to the fundamental social and environmental determinants of health such as water security, biodiversity, social justice, equitable access to resources, pollution, and land use planning have remained beyond the scope of most One Health programs despite their profound impacts on human and animal health and welfare (Stephen and Karesh, 2014). The increased knowledge of the role of animals in human diseases increased political and public awareness of risk interdependencies, thus fostering fear of animals, which in turn can lead to calls for their exclusion or elimination rather than improved understanding of how people and animals can safely live together (Decker et al., 2009). One Health has placed more effort on traditional public health actions to attack hazards, most often of infectious origin, rather than on creating supportive environments to enable people, animals, or environments to lead healthy lives.

Ecosystem Approaches to Health

Many health issues, whether in public health, conservation, or agriculture, are complex and best understood by paying attention to the interdependencies of human health, animal health, and the health of the ecosystems in which they live. EcoHealth (also known as ecosystem approaches to health) was pioneered at the International Development Research Centre to connect ideas of environmental and social determinants of health with ecology and systems thinking within a context of social and economic development. EcoHealth emphasizes the development of capacity and circumstances that enable individuals to make healthy choices and systems thinking to promote well-being and quality of life. EcoHealth is an explicit attempt to bring people into ecology, ecology into health, and health into community well-being.

EcoHealth recognizes that health is the result of the complex, dynamic interplay between the determinants of health and the conditions of ecosystems, often resulting from social and economic activities of people (as illustrated throughout Charron, 2012). By embracing ecology and complexity, EcoHealth admits it is deviating from the normal biomedical and epidemiological approach to health. Complex systems, like socio-ecological systems, are unpredictable and not well suited to research seeking a mechanistic truth (Holling, 1996). The systems thinking focus of EcoHealth encourages us to expand the boundaries of what is being studied as well as the set of people involved in generating that knowledge. EcoHealth tries to level the field between the external expert and the communities, shifting them from a researcher and research subject relationship to partners in discovering actions to make incremental improvements in health. The intent to solve problems, particularly those at the interface of human and natural systems, is shared by many EcoHealth projects. EcoHealth’s scope of practice is characterized by a work that “(i) is undertaken in the setting where results will be applied under conditions experienced by the populations of concern; (ii) strives to inspires effective, ethical, and sustainable actions in ‘real-world’ settings to address complex problems important to people in those settings, rather than discover underlying mechanisms of causation; and (iii) focuses on accelerating the integration of research with policy, and practices to promote action to solve problems” (Stephen et al., 2016).


Imagine a scene. You are looking at a marsh or a chicken farm or an urban park. Within that same space, there are many types of health. There is the health of individuals, populations, and ecosystems. There is the health of the plants, pests, valued animals, and their human caretakers. There is health as seen by the animal rights activists and health as seen by the social justice advocates. All these types of health coexist in the same place at the same time. The art of health promotion at the interface of animals, society, and environments is to find the common ground from which actions can be launched to promote and protect the health of one component of this system without harming the health of others.

Many types of health can be seen in Figure 2.1. At the bottom left, disease, in the form of trauma, can be seen - a California sealion with a neck wound due to entanglement with marine debris. The group of sealions was both promoting human community health by creating ecotourism jobs but at the same time reducing access to commercially and culturally important seafood species, thereby negatively impacting jobs as a determinant of health for others in the community. The eagle in the photo is vulnerable to lead poisoning, due to its habit of scavenging on carcasses killed by hunters using lead bullets while at the same time finding it harder to secure the needs for daily living due to competition for salmon with people and other animals and damage to their critical habitat in the foreshore. Human waste management and urbanization were changing the diets of the gulls, leading to larger population sizes and larger individual sizes of the gulls but with concurrent increased exposure to contaminants in their diets. The trees in the background were struggling with the effects of drought conditions. All these health effects were being influenced by anthropogenic changes in the local coastal ecosystem health that was affecting species distribution, habitat quality and connectedness, and climate change.

Insufficient data and a limited understanding of the cross-linking relationship between human, animal, and environmental health continue to challenge

There is not One Health, there are many. (Photo credit Craig Stephen.)

FIGURE 2.1 There is not One Health, there are many. (Photo credit Craig Stephen.)

attempts to find a universally applicable definition of health. But, at their core, health, well-being, and resilience each deal with situations, decisions, and actions that enable coping and even thriving in a changing world. As stated in the Ottawa Charter for Health Promotion, health can only be created and sustained when we encourage reciprocal maintenance - to take care of each other, our communities, and our natural environment.

Health is not like physics where we can measure and weight different attributes to find universal laws and make definitive proclamations on a state of nature. Health is an aspiration and a cumulative effect of interdependent personal, social, and environmental factors that change and evolve over a life course. There will, therefore, never be a single obvious opening into which the person working at the animal-health-society interface can step in and readily see the one true target of success. Health is a social construct rather than a biologically determined state. In other words, the act of characterizing and describing health is a uniquely human activity. Health is also a wicked problem. Wicked problems are characterized by uncertainty, complexity, and divergent values. There is no indisputable point at which one can declare objectively something is healthy in a way that everyone will agree. There is no ultimate state of health as health goals shift as social expectations change. Health is strongly stakeholder dependent, and there can be a wide variety of opinions on how to best recognize and produce a healthy situation. Health does not sit conveniently within the responsibility of any one organization or individual. Once we start comparing health across species and settings, this wicked problem gets even messier.

A key to seeking solutions to wicked problems is through mediated dialogue aimed at finding common ground about goals and directions (Head, 2008). This requires a broad systemic perspective that looks across boundaries, incorporates many types of evidence, and engages a diversity of interests to co-produce goals, plans, and actions. The willingness and ability to have “back-and-forth" relationship between context, values, and evidence form the basis for successful research and action at the animal-health-society nexus. Interspecies health promotion and harm reduction is about working across disciplines to listen and learn. Without understanding how to frame a health problem across species and generations so that it resonates with those people who need to act to protect the many types of health in a place, cooperative, collaborative action that protects the health of one species without harming the health of others cannot be achieved.


Amman, Brian R., Luke Nyakarahuka, Anita K. McElroy, Kimberly A. Dodd, Tara K. Sealy. Amy J. Schuh. Trevor R. Shoemaker et al. “Marburg Virus Resurgence in Kitaka Mine Bat Population after Extermination Attempts, Uganda.” Emerging Infectious Diseases, 20, no. 10 (2014): 1761.

Bennett, Nathan J., Robin Roth, Sarah C. Klain, Kai Chan, Patrick Christie, Douglas A. Clark. Georgina Cullman et al. “Conservation Social Science: Understanding and Integrating Human Dimensions to Improve Conservation." Biological Conservation, 205 (2017): 93-108.

Berkes, Fikret. Nancy C. Doubleday, and Graeme S. Cumming. “Aldo Leopold's Land Health from a Resilience Point of View: Self-Renewal Capacity of Social-Ecological Systems.” EcoHealth, 9, no. 3 (2012): 278-287.

Brown, Katrina, and Elizabeth Westaway. “Agency, Capacity, and Resilience to Environmental Change: Lessons from Human Development. Well-Being, and Disasters.” Annual Review of Environment and Resources, 36 (2011): 321-342.

Caporale, V., B. Alessandrini, P. D. Villa, and S. Del Papa. “Global Perspectives on Animal Welfare: Europe." Revue Scientifique et Technique-Office International des Epizooties, 24, no. 2 (2005): 567.

Chan, Cecilia, Petula Sik Ying Ho. and Esther Chow. “A Body-Mind-Spirit Model in Health: An Eastern Approach.” Social Work in Health Care, 34. no. 3-4 (2002): 261-282.

Charron, Dominique F.. “Ecohealth Research in Practice,” in Ecohealth Research in Practice (New York: Springer, 2012), 255-271.

Dale, Virginia H., and Suzanne C. Beyeler. “Challenges in the Development and Use of Ecological Indicators.” Ecological Indicators, 1. no. 1 (2001): 3-10.

Decker, Daniel J.. Kirsten M. Leong, and Darrick T.N. Evensen, “Perceptions of Wildlife- Associated Disease Risk: A Challenge or Opportunity for “One Health" in National Parks,” in Proceeding of the George Wright Society Conference, 2009 (2009): 101-106.

Ereshefsky. Marc. “Defining 'Health' and ‘Disease’.” Studies in History and Philosophy of Science Part C: Studies in History and Philosophy of Biological and Biomedical Sciences, 40, no. 3 (2009): 221-227.

Eriksson, Monica, and Bengt Lindstrom. “Antonovsky’s Sense of Coherence Scale and the Relation with Health: A Systematic Review.” Journal of Epidemiology & Community Health. 60, no. 5 (2006): 376-381.

Fraser. David, Daniel M. Weary. Edward A. Pajor. and Barry N. Milligan. “A Scientific Conception of Animal Welfare that Reflects Ethical Concerns.” Animal Welfare. 6, no. 3 (1997):187-205.

Gunnarsson, Stefan. “The Conceptualisation of Health and Disease in Veterinary Medicine.” Acta Veterinaria Scandinavica. 48, no. 1 (2006): 20.

Head, Brian W. “Wicked Problems in Public Policy.” Public Policy, 3. no. 2 (2008): 101.

Holling, Crawford Stanley. “Surprise for Science, Resilience for Ecosystems, and Incentives for People.” Ecological Applications. 6, no. 3 (1996): 733-735.

Huber, Machteld, J. Andre Knottnerus. Lawrence Green. Henriette van der Horst, Alejandro R. Jadad, Daan Kromhout. Brian Leonard et al. “How Should We Define Health?" British Medical Journal. 343, (2011): d4163.

Johnston, Fay H., Susan P. Jacups, Amy J. Vickery, and David MJS Bowman. “Ecohealth and Aboriginal Testimony of the Nexus between Human Health and Place.” EcoHealth, 4. no. 4 (2007): 489-499.

Kirkwood. J.K. and Sainsbury, A.W., 1996. Ethics of interventions for the welfare of free- living wild animals. ANIMAL WELFARE-POTTERS BAR-. 5. pp. 235-244.

Lackey, Robert T. “Values, Policy, and Ecosystem Health: Options for Resolving the Many Ecological Policy Issues We Face Depend on the Concept of Ecosystem Health, but Ecosystem Health Is Based on Controversial, Value-Based Assumptions that Masquerade as Science.” BioScience, 51. no. 6 (2001): 437-443.

Lancaster, Jill. “The Ridiculous Notion of Assessing Ecological Health and Identifying the Useful Concepts Underneath." Human and Ecological Risk Assessment: An International Journal. 6, no. 2 (2000): 213-222.

Lee, Michael J.. Kaylee A. Byers. Christina M. Donovan, Julie J. Bidulka, Craig Stephen, David M. Patrick, and Chelsea G. Himsworth. “Effects of Culling on Leptospira Interrogans Carriage by Rats.” Emerging Infectious Diseases, 24, no. 2 (2018): 356.

Leopold, Aldo. A Sand County Almanac and Sketches Here and There: Outdoor Essays and Reflections (New York: Oxford University Press, reprint 1989).

Lu. Jiaqi, Kathryn Bayne, and Jianfei Wang. “Current Status of Animal Welfare and Animal Rights in China.” Alternatives to Laboratory Animals, 41. no. 5 (2013): 351-357.

Lu. Yonglong. Ruoshi Wang, Yueqing Zhang, Hongqiao Su, Pei Wang, Alan Jenkins. Rober C. Ferrier et al. “Ecosystem Health Towards Sustainability.” Ecosystem Health and Sustainability, l,no. 1 (2015): 1-15.

McCrea, Rod, Andrea Walton, and Rosemary Leonard. “A Conceptual Framework for Investigating Community Wellbeing and Resilience.” Rural Society, 23, no. 3 (2014): 270-282.

Minteer, Ben A., and James P. Collins. “Ecological Ethics in Captivity: Balancing Values and Responsibilities in Zoo and Aquarium Research Under Rapid Global Change.” liar Journal. 54. no. 1 (2013): 41-51.

Niemi, Gerald J.. and Michael E. McDonald. “Application of Ecological Indicators.” Annual Review of Ecology, and Systematic, 35, (2004): 89-111.

Oura. Chris. Adana Mahase-Gibson, and Craig Stephen, eds. Caribbean Resilience and Prosperity through One Health (St. Augustine: University of the West Indies, 2017), 108.

Scott, K. 2005. “Population Health: Risk and Resistance.” Journal of Aboriginal Health, 2, no. 1 (2009): 2-5.

Stephen. Craig. Theresa Burns, and Ana Riviere-Cinnamond. “Pragmatism (or Realism) in Research: Is There an Ecohealth Scope of Practice?” EcoHealth, 13. no. 2 (2016): 230-233.

Stephen, C.. and W.B. Karesh. “Is One Health Delivering Results? Introduction.” Revue Scientifique et Technique-Office International des Epizooties, 33, no. 2 (2014): 375-392.

Stephen, Craig, and Joy Wade. “Wildlife Population Welfare as Coherence Between Adapted Capacities and Environmental Realities: A Case Study of Threatened Lamprey on Vancouver Island." Frontiers in Veterinary Science, 5, (2018): 227.

Stephen, Craig, and Joy Wade. “Testing the Waters of an Aquaculture Index of Well- Being.” Challenges, 10. no. 1 (2019): 30.

Stern, Paul C., Oran R. Young, and Daniel Ed Druckman. Global Environmental Change: Understanding the Human Dimensions (Washington. DC: National Academy Press, 1992), 320.

Summers, J. K.. L. M. Smith. J. L. Case, and R. A. Linthurst. “A Review of the Elements of Human Well-Being with an Emphasis on the Contribution of Ecosystem Services.” Ambio, 41. no. 4 (2012): 327-340.

Svalastog, Anna Lydia. Doncho Donev, Nina Jahren Kristoffersen, and Srecko Gajovic. “Concepts and Definitions of Health and Health-Related Values in the Knowledge Landscapes of the Digital Society.” Croatian Medical Journal, 58. no. 6 (2017): 431.

Tai, Michael Cheng-Tek. “An Oriental Understanding of Health.” Tzu Chi Medical Journal, 24, no. 2 (2012): 92-95.

Tountas. Yannis. “The Historical Origins of the Basic Concepts of Health Promotion and Education: The Role of Ancient Greek Philosophy and Medicine.” Health Promotion International, 24. no. 2 (2009): 185-192.

Wittrock, Julie. Colleen Duncan, and Craig Stephen. “A Determinants of Health Conceptual Model for Fish and Wildlife Health.” Journal of Wildlife Diseases, 55, no. 2 (2019): 285-297.

WHO. “The Ottawa Charter for Health Promotion." World Health Organization, 1986. https://www.who.int/healthpromotion/conferences/previous/ottawa/en/

WHO. “The Determinants of Health.” World Health Organization. 2020. https://www. who.int/hia/evidence/doh/en/

Wolf. Meike. “Is There Really Such a Thing as “One Health” ? Thinking About a More than Human World from the Perspective of Cultural Anthropology.” Social Science and Medicine, 129, (2015): 5-11.

< Prev   CONTENTS   Source   Next >