Future Trends in Zoonotic Diseases: What Lies Ahead?
The Ongoing Threat of Pandemics
Five years ago, the world was brought to a standstill by COVID-19, a disease that caught scientists off guard in numerous ways. Today, the risk of new infectious diseases remains as significant as ever. The main driver behind this risk? Ecosystem degradation, according to Camille Besombes, a specialist in zoonoses and epidemiologist at Sciences Po Médialab.
The Rise of Zoonotic Diseases
The scientific community widely agrees that the emergence and re-emergence of infectious diseases are becoming more frequent. This trend can manifest in two ways: the appearance of new infectious agents, like SARS-CoV-2 for COVID-19, or the spread of known agents in new regions or on an unexpected scale. Recent examples include MPOX, which emerged outside the African basin in 2022 and spread globally, particularly within the homosexual community.
One of the most worrying current issues is the H5N1 avian flu virus in the United States. Aviary influenza viruses are closely monitored due to their high mutation rates, ability to cross species barriers, and respiratory transmission, which facilitates interhuman spread.
The Impact on Biodiversity
These epidemics also pose a serious threat to biodiversity. Since 2021, the H5N1 virus has decimated wild bird colonies in France and Chile, and has also affected wild mammals, sea calves, foxes, and other species. Lastly year, the virus was detected in dairy cows in the United States and subsequently in humans who worked on these farms. While sustained interhuman transmission has not yet been reported, the risk increases with continued circulation.
In January 2024, the Intergovernmental Panel on Climate Change (IPCC) released a report highlighting the alarming rate at which wildlife populations are declining and how this decline is closely linked to the emergence of zoonotic diseases. According to the report, land-use changes, intensive farming, and trade in wild animals are among the primary drivers of these phenomena. Land-use changes alone account for over 50% of the total species extinction rate, according to the IPCC.
Weaknesses in Our Societies
The report "Escape the Pandemic Era" by the IPPES evaluates the weaknesses in our societies’ approach to pandemics. Experts highlight land-use changes, such as converting forests into agricultural or urban areas, as well as the decline of wetlands, which are crucial for migratory birds, as significant factors promoting the emergence of infectious diseases.
In March 2024, the World Health Organization (WHO) published a statement emphasizing the need to prioritize environmental conservation as part of public health strategies.
Climate Change and Disease Emergence
Climate change plays a crucial role in the emergence of infectious diseases, though it is often secondary to the impact of land-use changes. Its effects are most evident in vector diseases transmitted by mosquitoes or ticks. Climate change expands the geographical range of these vectors, exposing non-immune populations to new diseases.
The Socio-Ecological Determinants
There are areas of the world that are becoming structurally pathogenic due to ecological and social determinants, the Democratic Republic of Congo is one such example. Between 2020 and 2024, researchers documented the simultaneous emergence of zoonoses in deforested, mining and civil war affected areas.
The broader impacts of climate change are well documented, including recent outbreaks of respiratory diseases in California following wildfires.
Policy Response and Future Directions
States should agree to transformative changes in society and lifestyles, including stringent measures on agriculture, deforestation, and extractivism. However, recent trends suggest that such changes are not being adequately addressed. And adding to the uncertainties, The World Meteorological Organization (WMO) highlighted in a meeting in 2023 that there might be areas where diseases can proliferate unpredictably due to climatic unpredictability.
Zoonotic Disease Trend Table
| Disease | Year Emerged/Spread | Impact on Biodiversity | Primary Driver |
|---|---|---|---|
| Avian Flu (H5N1) | 2021-2024 | Decimated wild bird colonies in France, Chile | Changes in land use, intensive farming, wetlands degradation, climate change, international trade |
| MPOX | 2022 | Extensive spread among the homosexual community | Changes in land use, international trade, climate change, and biodiversity loss |
| SARS-CoV-2 (COVID) | 2019 | Decimated human population in many countries | International exchange, trade, climate change, habitat fragmentation |
FAQ
What are the most important factors driving the emergence of zoonotic diseases?
The primary drivers are changes in land use, such as deforestation and intensive farming, as well as international trade, industrialization and climate change. The IPPES 2023 report notes that land-use changes alone account for 50% of the total species extinction, creating conditions favorable for disease emergence.
What is the role of wetlands in preventing the spread of diseases like avian flu?
Wetlands are crucial resting and breeding grounds for migratory birds. The degradation of these habitats concentrates birds in fewer areas, increasing the likelihood of viral exchange.
How does climate change influence the emergence of zoonotic diseases?
Climate change expands the geographical range of disease vectors, exposes non-immune populations to new diseases, and creates conditions favorable for the emergence and spread of pathogens, such as changes in rainfall, extreme events and habitat fragmentation.
“Did You Know?”
Scientists project that by 2040, key habitats such as wetlands, peat lands and forests may be reduced by 40%. These ecosystems store carbon and regulate disease hazards, act as nature-based solutions to handle and mitigate climate risks. Land-use changes play a significant role in greenhouse gas emissions, disease outbreaks, habitat fragmentation and biodiversity.
Pro Tip
"A healthier planet for the anthropogenesis of newer diseases can be achieved through transformative shifts in our societies and lifestyles. We need to educate, change consumption patterns, prioritize the ecosystems and inter-sectoral approaches. Ambitious interventions are necessary to mitigate current and emerging zoonotic diseases”, expert and facilitator on “Permanent Secretariat of the Convention” comments (United Nations meeting).
Involve and Learn
Join us in raising awareness about the importance of ecosystem conservation in preventing zoonotic diseases. Share your thoughts and experiences in the comments below, and explore more articles on how we can achieve living in harmony with wild animals: "Learn to Live in Harmony with Wild Animals."
And don’t forget to subscribe to our newsletter for the latest updates and insights on the intersection of ecology and public health.
