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| A drylands vesper mouse in Argentina is among the rodent species studied in a UC Davis study that found rodent-borne viruses in South America are expected to increase and expand as temperatures rise and rodent habitats shift with climate change. Photo Credit: Ignacio Hernandez, ArgentiNat (CC BY-NC 4.0) |
Scientific Frontline: Extended "At a Glance" Summary: Climate Change and Arenavirus Spillover
The Core Concept: Rising global temperatures and shifting climate patterns are projected to drive rodent-borne arenaviruses into previously unaffected regions of South America over the next two to four decades, significantly increasing the risk of zoonotic spillover to new human populations.
Key Distinction/Mechanism: Unlike traditional disease tracking methods, this predictive research utilizes an open-source machine learning platform called AtlasArena to integrate complex variables—such as climate projections, land use changes, human population density, and shifting rat and mouse habitats—to map the precise future trajectory of viral transmission.
Major Frameworks/Components:
- AtlasArena Platform: An interactive, machine learning-driven modeling tool designed to analyze and project the risk of zoonotic spillover for hard-to-track pathogens.
- South American New World Arenaviruses: The research focuses on understudied viral strains including the Guanarito (Venezuela/Colombia), Machupo (Bolivia/Paraguay), and Junin (Argentina) viruses, which are known to cause severe hemorrhagic fevers with fatality rates between 5% and 30%.
- Environmental Variables: The models track complex ecological relationships among temperature fluctuations, precipitation shifts, and land use expansion (such as agriculture and urbanization) within rodent reservoir habitats.
Branch of Science: Veterinary Epidemiology, Infectious Disease Virology, Public Health, and Climate Science.
Future Application: The AtlasArena platform and its predictive models can be adapted to track other poorly monitored, climate-sensitive zoonotic diseases, allowing scientists to pinpoint future outbreak hotspots globally.
Why It Matters: Millions of people with no prior immunity may soon encounter these deadly viruses, underscoring an urgent need for coordinated, climate-adaptive public health policies and transboundary collaboration to mitigate future epidemics.
A study from the University of California, Davis, finds that climate change is likely to drive rodent-borne arenaviruses into parts of South America that have never faced these diseases, putting new communities of people at risk.
For the study, published in the journal npj Viruses, scientists incorporated climate projections, shifting rodent populations, and the risks of human infection into a model to offer an early risk projection for arenaviruses and other diseases in the next 20 to 40 years.
“As climate change accelerates, our study shows how the outbreak risk of dangerous New World arenaviruses could ride on shifting rodent populations to reach millions more people across South America,” said lead author Pranav S. Kulkarni, a postdoctoral scholar in the UC Davis Weill School of Veterinary Medicine and its Department of Population Health and Reproduction.
South American New World Arenaviruses
Arenaviruses can cause severe hemorrhagic fevers with high hospitalization rates and fatality rates ranging from about 5% to 30%. South American New World arenaviruses include Guanarito virus in Venezuela and Colombia, Machupo virus in Bolivia and Paraguay, and Junin virus in Argentina. Despite having caused multiple outbreaks in humans, they are relatively understudied compared to Old World arenaviruses, such as Lassa fever in Africa.
With funding from the Wellcome Trust, the researchers built an interactive, open-source platform called AtlasArena to understand how climate change is reshaping the risk of zoonotic spillover for arenaviruses and other hard-to-track viruses. They integrated climate projections, habitat suitability for six rat and mouse species linked to the viruses, human population density, and transmission risk into machine learning models. This approach allowed the team to identify complex relationships among climate, land use, rodent ecology, and human exposure that traditional models may miss.
Where Arenaviruses May Next Emerge
“Our study connects the dots between changing climatic conditions and land use, shifting rodent populations, and human infection risk, making it possible to see where the next generation of zoonotic arenaviral outbreaks could emerge,” said senior author Pranav Pandit, an assistant professor of veterinary epidemiology at the UC Davis Weill School of Veterinary Medicine.
For example, the models project that:
- Guanarito virus, which is found in central Venezuela, is expected to spread to parts of Colombia, the borders of Suriname, and northern parts of Brazil.
- Machupo virus is expected to move from the plains and flatlands of Bolivia to the Andes foothills and mountain regions.
- Junin virus is expected to move from the grassland regions to other parts of Argentina, reducing risk in some regions while expanding risk to other areas.
- In all cases, populations with little or no prior exposure would be encountering these viruses for the first time, potentially increasing their vulnerability to infection and severe disease.
The risk of spillover is primarily driven by changes in temperature, precipitation, and land use, such as expanding agricultural and urban areas within rodent reservoir habitats.
Coordinated, Transboundary Public Health Needs
The authors say the results underscore an urgent need for coordinated, climate-adaptive public health policies and transboundary collaboration among countries at risk.
“The first thing a study like this can inform is where we expect the risk to increase,” Kulkarni said. “Then we can look at why it is happening in more detail, identify ways to reduce the risk, and start planning for the long term and ways to reduce the spread of disease.”
Reference material: What Is: Zoonotic Spillover
Research material: AtlasArena
Published in journal: npj Viruses
Title: Climate-driven changes in zoonotic risk of arenaviral hemorrhagic fevers in South America
Authors: Pranav S. Kulkarni, Nuri Y. Flores-Pérez, Andie H. Jian, Brian H. Bird, Christine K. Johnson, Marcela Uhart, and Pranav S. Pandit
Source/Credit: University of California, Davis | Kat Kerlin
Reference Number: epi050426_01
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