About 9.3% of the world’s land area is highly vulnerable to dangerous disease outbreaks, according to new global modeling that identifies hotspots in Latin America and Oceania.
How the model defines high-risk zones
The research, led by Angela Fanelli at the European Commission’s Joint Research Centre, used machine learning and satellite data to map epidemic-prone diseases across nearly every country. It classified 6.3% of global land as high risk and another 3% as very high risk, based on environmental and socioeconomic drivers. Roughly 3% of the global population lives in these high or very high-risk zones, while 20% inhabit medium-risk areas.
Why population density outweighs climate factors
Population density emerged as the single strongest driver of outbreak risk in the model, surpassing individual influences like temperature, rainfall, or drought. Clearing forests for agriculture, roads, and mining increases human-wildlife contact, while dense settlements and industrial farms amplify opportunities for pathogens to jump and spread. Loss of biodiversity further favors species that carry dangerous viruses, compounding spillover potential.
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Where zoonotic threats are concentrated
Most diseases in the map are zoonotic, aligning with estimates that three-quarters of human emerging infections originate in animals. Climate shifts are expanding the range of disease-carrying mosquitoes and ticks into higher latitudes, while wildlife migration and habitat changes bring species closer to human settlements. The model includes all WHO priority zoonotic diseases, adjusted for detection bias, with white areas on the map indicating insufficient data for one or more predictor layers.
What does “highly vulnerable” mean in this context?
Areas labeled highly vulnerable face elevated risk of disease outbreaks due to a combination of environmental change, high population density, and limited capacity to detect or contain threats.
Which regions are most at risk?
Hotspots are concentrated in Latin America and Oceania, where communities already experience pressure from climate change and land development, increasing susceptibility to zoonotic spillover.
