A comprehensive approach to health
The One Health High Level Expert Panel (OHHLEP) defines One Health as ‘an integrated, unifying approach that aims to sustainably balance and optimize the health of people, animals and ecosystems.’
One Health targets multiple broad but interconnected threats, including:
- Loss of habitats and biodiversity
- Zoonotic diseases (those transmitted from animals to humans or humans to animals)
- Public health preparedness
- Climate change
- Food safety and security
Each threat is interconnected and must be addressed from a multisectoral and multidisciplinary perspective, which makes visions like One Health crucial. While it might seem like a progressive concept, the idea isn’t a new one. John Muir, Scottish naturalist and founder of the Sequoia and Yosemite national parks in the USA, summed up the intertwined nature of our world in 1911. His musings remain as relevant today as ever:
“When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” – John Muir, 1911, Scottish naturalist.
But how did we get here, over 100 years after John Muir’s observation, and what do these threats look like in 2025?
The challenges targeted by One Health
The human population has grown to an estimated 8.2 billion, causing problems for our overcrowded planet and everyone who lives here, animals and plants included. In the past, our human-centric viewpoint failed to recognize the importance of other species and environments, leading to severe consequences for all systems involved. One Health takes a more holistic, whole-systems view.
Here, we break down each interconnected issue.
Loss of habitats, biodiversity, and animal health
More humans mean changes in land use as humans expand into new geographical areas, wrecking habitats, ecosystems, and biodiversity in the process.
According to the Food and Agriculture Organization of the United Nations (FAO) Remote Sensing Survey, intensive agriculture and livestock farming account for 90% of global deforestation and are the leading cause of habitat destruction.
Find out more about how One Health initiatives are addressing loss of biodiversity in our article
This increase in agricultural land results in a loss of biodiversity and natural habitats and causes humans and domestic animals to have a closer proximity to wildlife. The poor health and low diversity of animals in an environment can have a bi-directional impact on humans and animals alike.
Zoonotic diseases
More human-animal contact increases the likelihood of transmission of zoonotic diseases like COVID-19. According to the World Organization for Animal Health, around 60% of known human infectious diseases originated in either domestic or wild animals. For new infectious diseases in humans, this number rises to 75%, highlighting the growing need to keep the animals and environment around us healthy, and for us to monitor the risks.
Discover how Belgian innovation in animal health is leading the One Health vision
For instance, in Belgium, researchers monitored animal reservoirs of the hepatitis E virus (HEV) that causes acute human liver disease to assess the dynamics of HEV infection between wild animals, domestic pigs, and humans. They found that wild boar are host reservoirs of the virus in Belgium but that deer are not, information that could potentially influence policy decisions.
Antimicrobial resistance
According to the FAO, livestock farming is a leading contributor to AMR due to overreliance on antibiotics. AMR is also one of the United Nations’ ten major threats to humanity, so we’ve included some deep dives into the challenges we’re facing in this special edition.
Read how we must change funding models to help develop novel antimicrobials
Find out how Belgian research is developing new antifungals
Climate change
Intensive livestock farming also requires excessive water consumption to grow feed crops and generates more greenhouse gases than the entire global transport sector. The resulting rising global temperatures exacerbate habitat loss both on land and at sea, with direct consequences for humans.
For instance, severe weather-related events triggered more than twice as many human displacements as those caused by conflict and violence, creating an average of 21.5 million new climate refugees each year over the past decade.
Food safety and security
Climate change and these other factors also lead to food insecurity, a core issue in this changing world, as around 811 million people go to bed hungry each night globally. That’s almost double the entire population of the European Union.
In line with this, water is also a foundational aspect of One Health because it is fundamental to all life, including our food. Drought is increasingly common, damaging crops. More industrialization leads to more chemicals, organic matter, microplastics, and other waste entering our water, which affects most organisms, food, and environments on the planet.
Shockingly, researchers recently found an amount of microplastics in the human brain equivalent to an entire standard plastic spoon. Even the harshest environments can’t escape. Scientists found microplastics at the top of Everest and the dark depths of the 11-kilometer-deep Mariana trench in the Pacific Ocean.
One Health policy in Europe
To address these challenges, One Health requires worldwide adoption for global impact. However, local collaborations can positively affect specific ecosystems, environments, and population health. In the European Union, the European Commission recently received a positive opinion from the Scientific Advice Mechanism (SAM), which provides independent scientific evidence and policy recommendations to governments. The report weighed the evidence of the One Health approach in the EU and reinforced the importance of collaboration across policy areas and disciplines while advocating for increased education, training, and greater promotion of research and innovation on One Health.
However, the SAM report also suggested that some EU policies would benefit from more emphasis on One Health. This suggestion primarily focused on food, agriculture, and the environment and stated that ‘a paradigm shift is needed towards more ecologically, socially and economically sustainable systems’ and that ‘the EU needs more integration between different policy areas both within the European Commission and among European institutions.’
One Health in Belgium
Belgium is taking the One Health approach seriously. For instance, the Federal Public Service Public Health has adopted One Health as the guiding principle for its work. Similarly, the federally funded Belgian research institute for health, Sciensano, uses a broad interpretation of One Health and includes as many environmental aspects as possible in its research.
Universities are also educating our future thought leaders in One Health principles with different programmes, including the Masters in Global One Health at the Institute of Tropical Medicine and the University of Antwerp’s Chair for care and the natural living environment.
To bring together all relevant stakeholders, including scientists, practitioners, citizens, and policymakers to support the local and global One Health effort, the Belgian One Health network (BeOH) was launched in 2019 and organizes annual conferences to facilitate discussion and progress in One Health.
While the challenges might seem overwhelming, we’re heading in the right direction to live in a world where the health of humans, animals, plants, and the environments we cohabitate brings benefits for all in a sustainable and equitable way.
