How Health as a catalyst for sustainable development

Recognizing that “the health of humans, domestic and wild animals, plants and ecosystems are closely linked and inter-dependent”1, One Health approaches aim to improve disease management by bringing together medical, veterinary and environmental scientists and policy specialists.

The number of citations to scientific papers reporting One Health research has grown exponentially since the early 2000s (Fig. 1), and particularly since the One World, One Health conference that was held in New York in 2004. Linking the emergence of zoonotic diseases to environmental degradation, the conference laid out an inclusive approach to preventing epidemic and epizootic disease while maintaining the integrity of ecosystems2. One World, One Health formulated the Manhattan principles, calling for “an interdisciplinary approach for combating threats to the health of life on Earth”.  health depends on and contributes to other development goals, underpinning social justice, economic prosperity and environmental protection

In my opinion, four key challenges need to be tackled for One Health approaches to be successful in their own right, and in the wider context of sustainable development.

The first challenge is to resolve the paradox of unconnected systems. The temporal and spatial dynamics of any system depend on the characteristics of its component parts and on the form of the interactions between them. One Health recognizes this for animals, people and the environment, but the same idea has separately motivated ‘Health in All Policies’ (Fig. 1) and ‘whole of society’ approaches, which argue that health should be represented in policies developed across all sectors of government and civil society3,4. It has been invoked, too, by complexity and network theories, planetary health, and the view of pandemics as syndemics, where the concurrent spread of multiple infections, such as COVID-19 and HIV/AIDS, is exacerbated by prevailing social, economic and environmental conditions. The mother of all systems is the network of 17 SDGs3. Yet, within the principal health goal (SDG 3), there remains a disconnect between the patient-focused preoccupation of clinical medicine and the population-level objectives of the SDGs. This assortment of overlapping but disjointed frameworks is a signal that, while systemic thinking has broad appeal, systemic action trails far behind. Transdisciplinary research and intersectoral practice are still the exceptions rather than the rule.

This lack of connectedness is one reason why progress towards meeting the SDGs by 2030 is not on track in most regions of the world5. Another reason, according to some critics of the sustainable development agenda, is that inclusivity is a recipe for inefficiency6. They argue that the SDGs comprise far too many poorly defined targets, with ambiguous criteria for success. They prefer the precision targeting of the millennium development goals (MDGs), predecessors of the SDGs, setting clear priorities in a world of limited resources. They point to the successes of the MDG era ─ for instance, the number of people living in extreme poverty; the malaria, tuberculosis and under-five mortality rates; and the maternal mortality ratio all fell by about one-half or more between 1990 and 2015 (ref. 3).

This critique of the SDGs sets up the second challenge: to define One Health programmes that are neither too narrow (missing chances for collaboration) nor too broad (difficult to manage and diluting priorities). Rabies is a good test of this challenge7. Vaccines that can be given both to animals and people should be effective in controlling zoonotic diseases. The global strategic plan to end human deaths from dog-mediated rabies by 2030 (ref. 8) urges “implementation of the One Health approach, embedded within strong human and animal health services”. But what is the optimal design of a One Health programme for rabies control? In general, rabies control programmes now recognize the value of a two-pronged attack on the disease, in humans and animals ─ post-exposure prophylaxis (rabies immunoglobulin and vaccination for people bitten by suspected rabid animals), plus mass vaccination of animal reservoirs, mainly domestic dogs, reduces the risk of human exposure and can potentially eliminate rabies9. The details of implementation vary from one setting to another. Success in Vietnam, for instance, was based on the decision to produce dog vaccines domestically (1994) followed by a prime-ministerial directive to prevent and control rabies nationally (1996), later reinforced by an explicitly One Health approach to multisectoral collaboration (2001)10.