What is One Health?

2021 saw the formation of the ‘Quadripartite Collaboration for One Health’, made up of the Food and Agriculture Organization of the United Nations (FAO), United Nations Environment Programme (UNEP), World Health Organization (WHO), and the World Organisation for Animal Health (WOAH) [2]. Their first task was to come up with the official definition for One Health which is as follows:

One Health is an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals and ecosystems. 

It recognizes the health of humans, domestic and wild animals, plants, and the wider environment (including ecosystems) are closely linked and interdependent. 

The approach mobilizes multiple sectors, disciplines and communities at varying levels of society to work together to foster well-being and tackle threats to health and ecosystems, while addressing the collective need for healthy food, water, energy, and air, taking action on climate change, and contributing to sustainable development [3]. 

Why is One Health important?

One Health Day underlines the importance of using the above approach to help find sustainable solutions to global health challenges and to tackle SDG3 targets. In particular, One Health could facilitate SDG targets 3.3: to end epidemics like Malaria, those of neglected tropical diseases and water borne diseases; and 3.d: improving early warning, management, and risk reduction of national and global health threats across the globe, and particularly in LMICs [4]. One Health Day draws attention to global health threats that are particularly prevalent and that urgently need a One Health approach to help solve them. At present these include emerging and re-emerging zoonotic diseases, the impact of climate and anthropological changes on the spread of diseases,  problems caused by increasing antimicrobial resistance (AMR), food safety and security, and pandemic preparedness and response [5].

The importance of a One Health approach was bolstered by the Covid-19 pandemic, zoonotic diseases are a prime example of the need to view health challenges from a holistic perspective. A great number of emerging infectious diseases are zoonotic, and their spillover to humans is often linked to things like habitat degradation and biodiversity loss, showing how interconnected human health is to both animal and environmental health [6]. A further example of this connection is the rise of mosquito and tick-borne diseases in Europe. Warmer temperatures, longer summers and increased rainfall caused by climate change is increasing the range of disease vectors like mosquitos and ticks to higher latitudes and altitudes [7]. The link is clear and shows that One Health needs to be integrated into research and policy to help mitigate threats to global health.

One Health in 2024

2024 has further highlighted the importance of this integrative approach. Following WHO declaring the mpox outbreak a public health emergency in August; the rapid spread of H5N1 among cattle in the US, and the problems associated with the overuse of antimicrobials and the ensuing antimicrobial resistance, the urgent need for this approach to be understood and utilised has become even clearer [8, 9, 10, 11].

In response to Mpox being declared a public health emergency, vaccine alliance GAVI utilised its First Response Fund to purchase 500,000 Mpox vaccines  [8, 12]. Preparedness procedures like First Response Funds are great in theory, but with an estimated 10 million vaccines needing rapid dissemination among virus-affected countries in Africa, and wealthy nations like the US, UK, and Japan stockpiling vaccine doses, in the case of Mpox the execution has left much to be desired. Integrating a multi-sectoral One Health approach into policy, and sharing data and resources across disciplines is necessary to ensure quicker vaccine roll outs and a more effective response to future epidemics.

(As of yesterday, 30th October, the first case of Mpox variant clade Ib has been detected in London)

The recent resurgence of H5N1 Avian Influenza throughout cattle populations in the US, and the possibility of 2 cases of human infection detected in Missouri, has shown how underprepared we are against the threat of zoonoses and potential pandemics [13, 14]. Despite the recent Covid-19 pandemic, One Health is still underutilised, and countries still lack frameworks for early detection and prevention of potential zoonotic disease spillover. Despite this being the first incidence of H5N1 found in cattle, it is not mandatory in the US to test and report on the disease in this species [15, 16]. Testing is only mandatory for poultry or lactating cattle intended to be moved from one state to another. The subsequent lack of data means the chain of transmission is not well understood. One Health emphasises the importance of early detection through the monitoring of wildlife, livestock and the environment. It provides a framework for surveillance systems that can detect potential spillover events at their source, before they reach human populations [17]. With zoonoses accounting for 75% of all emerging infectious diseases, and scientists acknowledging the risk of future pandemics arising from places like fur farms and live animal markets, it is imperative that we utilise these holistic One Health frameworks to monitor the health of animals for early disease detection and mitigation [18].

WHO lists antimicrobial resistance (AMR) as a prominent threat to global health, it is a natural occurring phenomenon exacerbated by overuse and misuse of antimicrobials [19]. A multifaceted One Health approach, adopted by human, animal, and environmental health organisations is required to stop the increase of AMR and address challenges it poses to disease treatment. Better sanitation, clean water, and reducing pre-emptive and indiscriminate antimicrobial use in livestock could help to tackle AMR and the spread of potentially life-threatening infections [20]. The 79th UN General Assembly met this September to discuss the problem; however, after push-back from high meat-producing nations, quantitative targets were omitted from the declaration [10]. Without specific targets it is hard to monitor countries commitments to addressing the problem of resistance and reducing their antimicrobial use. To fight the risk AMR imposes globally, One Health needs to be at the forefront of our actions against it.

Conclusion

One Health Day is an opportunity to encourage the integration of a more holistic approach to human, animal, and environmental health into research and policy. It draws attention to current global health challenges that could be viewed from a One Health perspective and provides frameworks to help overcome these challenges. Mobilising multiple sectors, sharing research across disciplines, and understanding the role that our surrounding environment can play in exacerbating global health threats are necessary to tackle these threats more effectively and help reach important SDG 3 targets.

For more Springer Nature content on One Health, visit our One Health Day 2024 webpage.

References:

1.       https://www.onehealthday.com/

2.       What is One Health? Global One Health Community https://globalohc.org/what-is-one-health

3.       Mettenleiter, T.C., Markotter, W., Charron, D.F. et al. The One Health High-Level Expert Panel (OHHLEP). One Health Outlook 5, 18 (2023). https://doi.org/10.1186/s42522-023-00085-2

4.       Ensure healthy lives and promote well-being for all at all ages United Nations https://sdgs.un.org/goals/goal3#targets_and_indicators

5.       What is One Health? One Health Commission https://www.onehealthcommission.org/en/why_one_health/what_is_one_health/

6.       Sonne, C. Why the next pandemic could come from the Arctic — and what to do about it. Nature 633, 10 (2024). https://doi.org/10.1038/d41586-024-02830-7

7.       Naddaf, M. Mosquito-borne diseases are surging in Europe — how worried are scientists? Nature 633, 749 (2024) doi: https://doi.org/10.1038/d41586-024-03031-y

8.       WHO Director-General declares mpox outbreak a public health emergency of international concern. WHO, News Release, 14 August 2024 https://www.who.int/news/item/14-08-2024-who-director-general-declares-mpox-outbreak-a-public-health-emergency-of-international-concern

9.       Ledford, H. Is bird flu spreading among people? Data gaps leave researchers in the dark. Nature Daily Briefing (Sept, 2024) doi: https://doi.org/10.1038/d41586-024-03089-8

10.   Gilbert, N. US pressure weakens global commitments on antimicrobial resistance. U.S Right to Know (2024)  https://usrtk.org/factory-farming/us-pressure-weakens-global-commitments-on-antimicrobial-resistance/?utm_source=Live+Audience&utm_campaign=64ce3b8bda-nature-briefing-microbiology-20240926&utm_medium=email&utm_term=0_b27a691814-64ce3b8bda-52715667

11.   UN General Assembly High-Level Meeting on antimicrobial resistance 2024. WHO https://www.who.int/news-room/events/detail/2024/09/26/default-calendar/un-general-assembly-high-level-meeting-on-antimicrobial-resistance-2024

12.   Ahmed, K. Global alliance buys half a million mpox vaccines for Africa. The Guardian (2024) https://www.theguardian.com/global-development/2024/sep/18/global-alliance-buys-half-a-million-mpox-vaccines-for-africa?utm_source=Live+Audience&utm_campaign=97786ed683-nature-briefing-microbiology-20240919&utm_medium=email&utm_term=0_b27a691814-97786ed683-52715667

13.   CDC Report on Missouri H5N1 Serology Testing. CDC (2024) https://www.cdc.gov/bird-flu/spotlights/missouri-h5n1-serology-testing.html#:~:text=The%20Missouri%20case%20and%20their,patient%20and%20their%20household%20contact.

14.   Mandavilli, A., Anthes, E. Possible Cluster of Human Bird-Flu Infections Expands in Missouri The New York Times (2024) https://www.nytimes.com/2024/09/27/health/bird-flu-cluster-missouri.html?unlocked_article_code=1.PU4.nvpB.rnV5o8OGIoaW&smid=url-share&utm_source=Live+Audience&utm_campaign=a3a9b56233-nature-briefing-microbiology-20241003&utm_medium=email&utm_term=0_b27a691814-a3a9b56233-52715667

15.   Current H5N1 Bird Flu Situation in Dairy Cows. CDC (2024) https://www.cdc.gov/bird-flu/situation-summary/mammals.html

16.   Shnirring, L. Review finds serious gaps in steps to control avian flu in mammals. Center for Infectious Disease Research and Policy (2024) https://www.cidrap.umn.edu/avian-influenza-bird-flu/review-finds-serious-gaps-steps-control-avian-flu-mammals?utm_source=Live+Audience&utm_campaign=a3a9b56233-nature-briefing-microbiology-20241003&utm_medium=email&utm_term=0_b27a691814-a3a9b56233-52715667

17.   Bartlett, M., Uhart, M. Leveraging one health as a sentinel approach for pandemic resilience. Virol J 21, 269 (2024). https://doi.org/10.1186/s12985-024-02545-1

18.   Mandavilli, A. Bird Flu Has Already Appeared in New York’s Animal Markets. What’s Next? The New York Times (2024) https://www.nytimes.com/2024/09/09/health/bird-flu-wet-markets.html

19.   Antimicrobial Resistance (AMR). United Nations Environment Program https://www.unep.org/topics/chemicals-and-pollution-action/pollution-and-health/antimicrobial-resistance-amr#:~:text=What%20is%20the%20impact%20of,development%20and%20equity%20within%20societies.

20.   Ndahi, M.D., Hendriksen, R., Helwigh, B. et al. Determination of antimicrobial use in commercial poultry farms in Plateau and Oyo States, Nigeria. Antimicrob Resist Infect Control 12, 30 (2023). https://doi.org/10.1186/s13756-023-01235-x