Introduction

One Health is a scientific approach that recognizes the interconnectedness of human, animal, and environmental health. It emphasizes collaboration across multiple disciplines—such as medicine, veterinary science, ecology, and public health—to address health challenges that arise at the interface of people, animals, and their shared environments. The concept is increasingly important as global populations grow, habitats change, and diseases emerge across species boundaries.

Main Concepts

1. Interconnected Health

  • Human Health: Diseases and health conditions in humans can be influenced by interactions with animals and the environment. Examples include zoonotic diseases (those that jump from animals to humans) like COVID-19, rabies, and influenza.
  • Animal Health: Domestic and wild animals can carry pathogens that affect humans and other animals. Their health is also impacted by environmental changes, pollution, and human activities.
  • Environmental Health: The environment provides resources and habitats for all living things. Pollution, climate change, deforestation, and habitat loss can disrupt ecosystems, increasing the risk of disease transmission.

2. Zoonotic Diseases

Zoonoses are diseases that can be transmitted from animals to humans. Over 60% of emerging infectious diseases are zoonotic. Examples include:

  • COVID-19: Caused by the SARS-CoV-2 virus, likely originating from animals.
  • Ebola: Linked to contact with infected wildlife.
  • Avian Influenza: Transmitted from birds to humans.

3. Antimicrobial Resistance (AMR)

AMR occurs when bacteria, viruses, or parasites no longer respond to medicines, making infections harder to treat. Overuse of antibiotics in humans and animals contributes to AMR. One Health encourages responsible use of antimicrobials across sectors.

4. Food Safety and Security

Foodborne illnesses can result from contamination at any point in the food supply chain. One Health promotes safe agricultural practices, proper animal husbandry, and environmental management to reduce risks.

5. Environmental Changes

Human activities such as deforestation, urbanization, and climate change alter ecosystems, affecting disease patterns. For example, habitat destruction can force wildlife closer to humans, increasing the risk of disease spillover.

Timeline: Key Milestones in One Health

  • 1800s: Early recognition of zoonoses (e.g., rabies transmission).
  • 1964: Calvin Schwabe coins “One Medicine,” precursor to One Health.
  • 2004: Wildlife Conservation Society hosts the “One World, One Health” symposium.
  • 2008: FAO, WHO, and OIE formalize One Health collaboration.
  • 2020: COVID-19 pandemic highlights the importance of One Health.
  • 2022: WHO launches the One Health High-Level Expert Panel to advise on global health threats.

Case Studies

Case Study 1: COVID-19 Pandemic

The COVID-19 pandemic demonstrated the importance of One Health. The virus is believed to have originated in animals and jumped to humans, possibly through wildlife markets. Collaboration between medical doctors, veterinarians, and environmental scientists was crucial for understanding transmission and developing control strategies.

Case Study 2: Rift Valley Fever in Kenya

Rift Valley Fever is a mosquito-borne disease affecting livestock and humans. Outbreaks often follow heavy rains and flooding, which increase mosquito populations. One Health approaches in Kenya include joint surveillance by public health and veterinary agencies, vaccination campaigns, and environmental monitoring.

Case Study 3: Antimicrobial Resistance in India

A 2021 study published in Nature Communications found that antibiotic-resistant bacteria in Indian rivers were linked to both human and animal waste. Researchers recommended integrated water management and responsible antibiotic use in healthcare and agriculture, demonstrating One Health principles in action.

Future Trends

1. Integrated Surveillance Systems

Technological advances are enabling real-time monitoring of diseases across humans, animals, and environments. Data sharing between sectors will improve early detection and response.

2. Climate Change Adaptation

As climate change alters habitats and disease vectors, One Health strategies will focus on predicting and mitigating new health threats. For example, rising temperatures may expand the range of mosquitoes carrying diseases like malaria and dengue.

3. Urbanization and Wildlife Encroachment

Growing cities increase contact between humans and wildlife. Future One Health initiatives will address urban planning, wildlife corridors, and safe food markets to reduce disease risks.

4. Global Policy and Collaboration

International organizations are strengthening One Health frameworks. The WHO’s One Health High-Level Expert Panel (2022) is guiding global responses to pandemics, AMR, and food safety.

5. Education and Workforce Development

There is a growing emphasis on training professionals in interdisciplinary One Health approaches. Schools and universities are developing new curricula to prepare the next generation of scientists.

Recent Research

A 2022 article in The Lancet Planetary Health (“One Health: a call for action in the COVID-19 era and beyond”) emphasized that preventing future pandemics requires breaking down barriers between human, animal, and environmental health sectors. The authors called for increased investment in One Health research, policy, and education to address global health threats.

Conclusion

One Health is a comprehensive, collaborative approach to health that recognizes the deep connections between people, animals, and the environment. By integrating knowledge and resources across disciplines, One Health aims to prevent and control diseases, improve food safety, combat antimicrobial resistance, and address emerging challenges like climate change. As the world faces new health threats, One Health will play a vital role in protecting the health of all living things and the planet itself.

Did you know? The largest living structure on Earth is the Great Barrier Reef, visible from space. This ecosystem is an example of how environmental health supports both animal and human well-being, illustrating the principles of One Health in action.