What Earth observations can tell us about hantavirus risk

Satellites, species & stethoscopes: a series discussing topics from the latest literature on Earth observation and animal health, and how it connects to human and ecosystem health

What reservoir ecology and environmental change can teach us about anticipating spillover

When hantavirus makes headlines, attention understandably focuses on human cases. But by the time a person becomes sick, a much larger ecological story has already unfolded.

In a recent journal article, Lauren Charles, Jennifer Nuzzo and Natasha Bagdasarian argue that understanding hantavirus risk requires looking beyond individual outbreaks and toward the environmental and ecological conditions that create opportunities for spillover.

That makes hantavirus an excellent case study of Animal GeoHealth in action.

Hantaviruses are maintained in animal reservoir populations, particularly rodents. Human infections generally occur when people encounter infected animals or virus-contaminated environments.

But those encounters do not happen randomly.

Reservoir ecology, environmental variability, landscape conditions, and human behaviour interact to determine when and where spillover becomes more likely. As environmental conditions change, the abundance and distribution of reservoir species can change as well, potentially creating new opportunities for animals, pathogens, and people to intersect.

Ongoing environmental change may alter the geography of hantavirus risk while challenging surveillance systems that rely heavily on detecting human disease after exposure has already occurred.

This is where the view from above becomes valuable.

Earth observations can help us characterise the environmental conditions that drive changes in reservoir populations and opportunities for spillover.

Satellite and other geospatial observations can provide information about vegetation, precipitation, temperature, land cover, drought, habitat conditions, and environmental disturbances across enormous geographic areas and over time.

Combined with animal, pathogen, and human health information, these environmental observations can help us ask a more useful question:

Can we recognise ecological conditions associated with changing disease risk before human cases provide the warning?

Ecological and animal surveillance tells us what is happening in reservoir populations. Human health surveillance tells us when those changing risks ultimately result in disease.

All of this opens up the possibility of moving from disease detection toward risk anticipation.

Similar relationships among environmental conditions, animal populations, pathogens, and people are at play across many One Health challenges, from vector-borne and wildlife diseases to harmful algal blooms, livestock heat stress, food security, and emerging zoonotic threats.

Human cases are only part of the hantavirus story. By connecting environmental and health observations, there are opportunities to recognize risk earlier, before people start getting sick. The opportunity for Animal GeoHealth is to connect these different observations in ways that help us better identify meaningful changes in risk and ultimately support better decisions.

To find out more about how Earth observations and geospatial data can inform the development of practical solutions to animal, environment and ecosystem health challenges, visit the Animal Health Work Group.

This blog is part of a series in which Lauren Charles and Karen Gruszynski, co-leads of the GEO Health CoP Animal Health Work Group, who discuss topics from the latest literature Earth observation and animal health, and how it connects to human and ecosystem health.

Featured this month:

Charles LE, Nuzzo JB, Bagdasarian N. Watching the Ship, Missing the Forest: Why Ecological Spillover, Reservoir Ecology, and Environmental Change Remain the True Hantavirus Threats in North America. The Journal of Infectious Diseases. Published online July 10, 2026. doi:10.1093/infdis/jiag359.