Deforestation: How the Destruction of Forests Paves the Way for Future Pandemics

The accelerating loss of tropical forests is no longer just an environmental crisis—it is a structural risk factor contributing to global health risks. A recent review of the scientific literature shows that deforestation and the fragmentation of natural habitats promote the emergence of zoonoses—infectious diseases transmitted from animals to humans.  

Deforestation and Zoonoses: The Key Role of Biodiversity Loss

By converting forest ecosystems into agricultural, mining, or urban areas, human activity removes ecological barriers that previously limited the spread of pathogens. Wild species forced to relocate come into closer contact with human populations and domestic animals, creating interfaces that facilitate the spread of disease. Epidemiological literature shows that regions where forest cover is rapidly declining are experiencing an increase in diseases such as malaria, yellow fever, leishmaniasis, and hantavirus infection. This mechanism is now well documented. Biodiversity loss eliminates so-called “dilutive” species—those unable to effectively transmit pathogenic agents—while generalist species (rodents, bats, mosquitoes) proliferate; these are often excellent reservoirs or vectors for pathogens. Landscape fragmentation increases the number of edge zones—true transmission hotspots where humans, farm animals, and wildlife live in close proximity.  

Public health also begins at the forest edge

Tropical forests thus play a quiet but decisive role in regulating diseases. Their destruction transforms viruses that were once confined to circulation within wildlife into a global health threat. Data from the Amazon and the Brazilian Atlantic Forest illustrate this phenomenon: the weakening of environmental policies in these regions coincides with a resurgence of infectious diseases in recently deforested areas. Protecting forests is as much a matter of disease prevention as it is of nature conservation. At a time when pandemics serve as a stark reminder of the interdependence between human health, animal health, and ecosystem health, the preservation of natural habitats emerges as one of the most effective and least costly ways to reduce future health risks.