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One Health: An Evolving Concept in Holistic Healthcare

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Dr. Soja Saghar Soman

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Dr. Soja Saghar Soman is a scientist working in the frontier areas of Biotechnology and Bioengineering. She holds undergraduate and master’s degrees in Veterinary Medicine and PhD in Biotechnology. Her career and expertise spans across pharmaceutical industry, UAE federal government and US academia. Her current research focuses on developing cutting edge medical diagnostics, medical devices and technologies, novel drug discovery platforms using bioengineering and bioprinting, and comparative immunology. Currently Dr. Soja is working with New York University Abu Dhabi.

The One Health approach recognizes the interconnectedness of people, animals, and the environment. It operates across local, regional, national, and global levels to improve coordination and collaboration in healthcare. With a focus on achieving optimal health outcomes, this approach addresses shared health threats such as zoonotic diseases, antimicrobial resistance, food safety, and climate change. By promoting a more integrated approach to healthcare, it inspires us to work together towards a sustainable future while supporting global health security.

Introduction:

One Health is an all-inclusive approach to optimize the health of people, animals, and the environment1. One Health approach reinforces that the health of people is closely linked to the health of animals and the health of the environment we are living2. As most of the diseases are transmittable between the species, the knowledge about the interconnectedness of the above three components is necessary to gain deeper understanding about the mechanisms of health and disease. Ideas on One Health has gained significant attention in recent years in the advent of global challenges such as COVID -19 pandemic, and other emerging infectious diseases such as Avian flu, Swine flue, Middle East Respiratory Syndrome (MERS), and NIPAH fever3,4. Moreover, concerns over the spread of antibiotic resistant microbes, merging of ecosystem boundaries, and the effect of climate change in marine and terrestrial life are also directing to the need of a comprehensive healthcare approach5. So, the establishment of One Health would be crucial to prevent disease outbreaks, improve food safety and security, reduce antimicrobial-resistant infections, and aid the ongoing biodiversity and conservation efforts. A brief view on the major areas covered under the scope of One Health is described in this article. 

Figure. 1. One Health is an all-inclusive approach to optimize the health of people, animals, and the environment. Figure created with Biorender.

The global burden of emerging infectious diseases: The current century has witnessed a wave of severe infectious disease outbreaks, not just the COVID-19 pandemic, which has had a devastating impact on lives and economies around the world. Many of the emerging infectious diseases affecting humans traces its origins in animals. Diseases such as HIV/AIDS, Ebola, Zika, and COVID-19 pandemic are zoonotic in nature, meaning they are originated or transmitted between animals and humans. Studying the immunopathology of zoonotic diseases in the natural reservoir hosts, rather than traditional animal models, offers greater insights into control strategies6. Elucidating the comparative immunology of zoonotic diseases affecting domesticated animals, wild animals and humans is crucial for unravelling the complex disease mechanisms involved in spreading these infections. This understanding will help in  developing new strategies for disrupting zoonotic transmissions7 (Figure.2.). The implementation of  One Health is critical in managing these zoonoses. It can help in monitoring and controlling diseases at the animal source and understanding the host factors and environmental factors that contribute to the disease spread.

Figure. 2. The intricate zoonotic network of pathogens: Many zoonotic agents cause little or no signs of disease in their natural hosts, such as wild birds and bats, but transmission hosts might present with disease symptoms ranging from moderate to severe leading to high mortality and pandemic incidences. One Health approach is a holistic healthcare way to control these incidences. Picture adapted from Bean. A.G.D. et al., 20137.

Disease surveillance systems and control measures: Effective disease surveillance systems are essential for the early detection and control of diseases at the human-animal-environment interface. One Health promotes the timely sharing of information and resources across different sectors to improve the effectiveness of surveillance and control. A collaborative, multisectoral, and transdisciplinary approach — working at the local, regional, national, and global levels — is required to achieve optimal health outcomes. Surveillance and disease control systems under One Health framework are designed to prevent and control diseases across species and ecosystems by monitoring and analyzing health data collectively. These systems involve: Data collection and analysis from human, animal, and environmental sources, risk assessment, communication in a timely manner, and response coordination8. For example, the surveillance systems could track the spread of zoonotic diseases such as avian influenza or rabies, by combining data from veterinary services, wildlife organizations, and public health agencies. Based on the data, the disease control measures might put in place, which include vaccination campaigns, wildlife management strategies, and public health interventions. These measures are crucial for early detection of potential pandemics, controlling endemic diseases, and ensuring the judicious use of antibiotics and vaccines. 

The emergence of antibiotic resistant pathogen strains: The overuse and misuse of antibiotics in food producing animals is identified as a major cause for the spread of antibiotic resistant bacteria in human and environment. One Health approach emphasizes that antibiotic resistance is not just a healthcare issue but a broader ecological and societal challenge that requires integrated and collaborative efforts to manage effectively. For tackling antibiotic resistance, the following One Health approaches can be implemented: Data collection and sharing to understand and monitor the spread of particular antibiotic resistant strains, regulating and optimizing the use of antibiotics in food animals and humans, promoting alternatives to antibiotics, educating the stakeholders like farmers, healthcare professionals, environmentalists and public, and ensuring international collaboration to curtail the spread.

Climate change and its impact on health: Climate change is a real global issue that impacts human and animal health in various ways. Changes in climate affect the distribution of vector-borne diseases, animal ecosystem displacements, habitat loss, food security, and the incidence of extreme weather events. A 2022 journal paper in Nature Climate Change states that 58% (218 out of 375 surveyed) of infectious diseases affecting human beings have been aggravated by “climatic hazards” linked to global greenhouse gas emissions9. One Health recognizes the need for a collaborative approach to study these impacts and develop adaptation strategies10. The recent COP28 (United Nations climate conference) held in Dubai paid significant attention to the intersection of climate change and health, marking a pivotal moment in integrating healthcare concerns into the broader climate agenda. The conference, which took place from November 30 to December 12, 2023, in Dubai, UAE, featured the first-ever "Health Day" on December 3, facilitated by a collaboration among the COP28 presidency, the World Health Organization (WHO), and the Wellcome Trust. This day highlighted the urgent need to address the health impacts of climate change, which is often referred to as the greatest global health threat of the 21st century. The event culminated in the COP28 UAE Declaration on Climate and Health, signed by over 140 countries, which calls for increased action and investment in health adaptations to climate change, as well as mitigation efforts to reduce greenhouse gas emissions. The declaration reiterated the importance of a One Health approach, and highlighted the need for improved early warning systems, climate-ready health workforces, sustainable food security systems honoring every species and measures to combat inequality11. This involves interdisciplinary collaboration among physicians, veterinarians, environmental scientists, public health professionals, and policymakers.

Research and One Health education: One Health encourages research that spans across many disciplines related to human health, veterinary science, environmental science, biotechnology, comparative immunology, vaccine development, bioengineering and other relevant fields7. This includes studies on the ecology and immunopathogenesis of diseases, the impact of environmental changes on health, the development of effective preventive strategies, robust diagnostics and treatment methods. Education and training programs are also important to foster a new generation of health professionals equipped with the One Health mindset focusing on understanding how ecosystems, human health, and animal health influence one another and how these insights can lead to better health outcomes across the globe. Educational institutions, governments, international organizations, and non-governmental organizations should take initiatives to integrate One Health education into degree programs, professional development courses, and public awareness campaigns, enabling the future generations to tackle the complex health challenges happening in our interconnected world.

Challenges and future directions: One Health is being implemented at both global and local levels. International organizations such as the World Health Organization (WHO), the Food and Agriculture Organization (FAO), and the World Organisation for Animal Health (formerly OIE), Centers for Disease Control and Prevention (CDC) One Health Office and the United Nations Environment Programme (UNEP) are promoting One Health. At the local level, communities are implementing One Health strategies tailored to their specific health and environmental challenges. One Health initiates should move forward by resolving several challenges, including the need for improved collaboration across sectors, generate expertise and funding for interdisciplinary research, and the development of comprehensive health policies. The future of One Health lies in strengthening these collaborations and continuing to advocate for a comprehensive understanding of health that includes humans, animals, and the environment.

References: 

  1. Gamble, A., Olarte-Castillo, X. A. & Whittaker, G. R. Backyard zoonoses: The roles of companion animals and peri-domestic wildlife. Sci Transl Med 15, eadj0037 (2023). https://doi.org:10.1126/scitranslmed.adj0037
  2. Baker, R. E. et al. Infectious disease in an era of global change. Nature Reviews Microbiology 20, 193-205 (2022). https://doi.org:10.1038/s41579-021-00639-z
  3. Albery, G. F. et al. The science of the host–virus network. Nature Microbiology 6, 1483-1492 (2021). https://doi.org:10.1038/s41564-021-00999-5
  4. Morens, D. M., Folkers, G. K. & Fauci, A. S. The challenge of emerging and re-emerging infectious diseases. Nature 430, 242-249 (2004). https://doi.org:10.1038/nature02759
  5. Allen, T. et al. Global hotspots and correlates of emerging zoonotic diseases. Nature Communications 8, 1124 (2017). https://doi.org:10.1038/s41467-017-00923-8
  6. Soman, S. S., Arathy, D. S. & Sreekumar, E. Discovery of Anas platyrhynchos avian β-defensin 2 (Apl_AvBD2) with antibacterial and chemotactic functions. Molecular Immunology 46, 2029-2038 (2009). https://doi.org:https://doi.org/10.1016/j.molimm.2009.03.003
  7. Bean, A. G. D. et al. Studying immunity to zoonotic diseases in the natural host — keeping it real. Nature Reviews Immunology 13, 851-861 (2013). https://doi.org:10.1038/nri3551
  8. Hayman, D. T. S. et al. Developing One Health surveillance systems. One Health 17, 100617 (2023). https://doi.org:https://doi.org/10.1016/j.onehlt.2023.100617
  9. Mora, C. et al. Over half of known human pathogenic diseases can be aggravated by climate change. Nature Climate Change 12, 869-875 (2022). https://doi.org:10.1038/s41558-022-01426-1
  10. Sheather, J. One Health and climate change—we need to get the ethics right. BMJ 383, p2177 (2023). https://doi.org:10.1136/bmj.p2177
  11. Maclane Speer, J. S. M. Bridging Health and Climate at COP28, (2023).