New global modeling shows that about 9.3% of the world’s land area is highly vulnerable to the risk of dangerous disease outbreaks.
These hotspots are concentrated in Latin America and Oceania, where communities already face pressure from climate change and land development.
The research also identifies the countries most vulnerable to outbreaks – and the least equipped to detect and contain them.
What this disease risk map reveals
Using machine learning and satellite data, researchers mapped epidemic-prone diseases across nearly every country on Earth.
The work was led by Angela Fanelli, a veterinary epidemiologist at the European Commission’s Joint Research Centre (JRC).
Her research focuses on how human-driven environmental change shapes epidemic risk and strains countries’ abilities to respond effectively to crises.
The model showed that 6.3 percent of global land area falls into the high-risk category, with another 3 percent classified as very high risk.
Roughly 20 percent of people live in medium risk areas, while 3 percent inhabit zones of high or very high-risk.
Zoonotic threats and disease risk
Most of the diseases in the map are zoonotic – diseases that move from animals to people through infection and contact.
One overview estimated that around three quarters of emerging infections in humans, worldwide, start in other animals.
When people expand settlements into forests or wildlife markets, that crowding raises spillover, the moment that a virus crosses into humans.
All of the WHO priority diseases in this map sit on a short list of carefully monitored dangerous zoonotic threats.
Climate patterns and outbreaks
Warming air and water change where animals, insects, and viruses can thrive – which reshapes the basic geography of infectious disease.
The new modeling suggests that higher temperatures, heavier rainfall, and deeper droughts all push the outbreak risk upward.
Recent research links climate change with altered migration routes, breeding cycles, and habitats that bring wildlife closer to people.
Longer warm seasons let disease-carrying mosquitoes and ticks survive in new places, pushing previously tropical infections into higher latitudes.
Human land use stacks the deck
Clearing forests for farms, roads, and mines moves people into closer contact with wildlife that can host new viruses and pathogens.
Packing many people and animals into dense settlements and industrial farms boosts opportunities for viruses to jump and spread quickly.
In addition, losing biodiversity, the variety of plant and animal life in an ecosystem, can sometimes favor species that carry dangerous pathogens.
In the new work, population density emerged as the single strongest driver of outbreak risk, outweighing any individual environmental factor.
Risk of the WHO priority diseases, bias adjusted. The map displays the risk levels across different regions, with white areas indicating insufficient data for one or more predictor layers. Credit: Science Advances. Click image to enlarge.
Who is ready and who is not
To move from raw hazard to real-world danger, the researchers built an epidemic risk index that combines outbreak likelihood with response capacity.
Countries like Papua New Guinea and the Republic of Congo sit on top, facing intense risk but limited health infrastructure.
This index does not assign blame. It reveals where clinics, laboratories, and trained staff may be overwhelmed by a fast-moving outbreak.
In contrast, many high-income countries show low outbreak risk yet strong capacity, making them potential hubs for laboratory support and vaccine manufacturing.
What high disease risk means
Even if you live far from a highlighted hotspot, the timing and location of outbreaks shape travel patterns, trade, and supply chains.
Modern air travel can move an infected person between continents in hours, but the strength of health systems determines what happens next.
Large populations live in places where the model shows moderate risk, meaning local health services could still be strained during a severe outbreak.
Preparedness does not only relate to the number of hospital beds available locally. It also includes early disease detection, clear communication, and reliable access to vaccines.
Using predictive models before crises hit
Computer models that learn from past outbreaks can flag places where dangerous viruses are likely to appear before doctors see cases.
In this study, algorithms combined satellite imagery, climate records, land use maps, and past infections to estimate where future outbreaks might begin.
Another study ranked virus families by pandemic potential to help governments decide which vaccines to develop in advance more efficiently.
Tools like these cannot tell us exactly which virus will emerge, but they narrow the possibilities and guide targeted surveillance and stockpiles.
Preparing for Disease X
The WHO keeps its short priority list under constant revision, adding unknown threats under the placeholder name Disease X, to encourage flexible preparedness.
In Europe, the Health Emergency Preparedness and Response Authority focuses on climate sensitive threats like Ebola, Zika, and Crimean Congo hemorrhagic fever.
Global cooperation on surveillance data, vaccine platforms, and rapid financing means that a cluster in one country can spark protective action elsewhere.
This map that no one wants to see works as a warning and planning tool. It shows where support must arrive before outbreaks become established.
The research was published in the journal Science Advances.
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