90-Second Read: How climate change could help Hantavirus find more hosts

Weather extremes exacerbated by global warming change how rodents behave, according to Kirk Douglas, a senior scientist who studies Hantaviruses and climate change at the University of the West Indies, Cave Hill, in Barbados. Hantavirus is sensitive to the changes climate change will bring," Douglas emphasized. It's all dependent on what the prevailing climate impact is." That complexity makes Hantavirus risk difficult to predict, and easy to overlook. Hantaviruses are an ancient family of rodent-borne pathogens that likely caused disease in humans long before they first appeared in medical records in the 1950s. Argentina's health authorities have already documented a sharp rise in Hantavirus this season : 101 infections have been recorded since June 2025, about twice as many as there were in the same period a year earlier.

The country's health ministry hasn't yet determined what's behind the surge, but research suggests that climate change may play a role. Here's How That doesn't mean there's a one-to-one relationship between global temperature rise and rodent-driven risk, however, and climate change is hardly the only force at play. In the United States, Hantavirus has been rare since federal surveillance began in 1993. A complex web of natural and manmade landscape changes can increase or decrease contact between humans and rodents. There were fewer than 1,000 total confirmed cases up to 2023, the latest year that data is available.

Andes Hantavirus, the strain that gripped the MV Hondius on its polar cruise, is one of a few Hantaviruses known to cause Hantavirus pulmonary syndrome, a rare but often deadly illness. The Andes strain is also the only known Hantavirus that can be transmitted human-to-human, a characteristic turning a rare rodent-borne infection into a multinational emergency, just a few years after the world was caught flat-footed by the COVID-19 pandemic. The good news is that the Andes Hantavirus, while uniquely deadly, is likely nowhere nearly as transmissible as COVID-19. Increased temperatures and humidity, for example, don't seem to influence the disease ecology of Hantavirus in the same way that drought and precipitation do. Experts say extreme weather is boosting the odds that the pathogens carried by rodents will spill over.

Grist is the only award-winning newsroom focused on exploring equitable solutions to climate change. Instead, we rely on our readers to pitch in what they can so that we can continue bringing you our solution-based climate news. The cruise ship departed Ushuaia, Argentina, in April with plans to ferry 147 passengers and crew members to some of the most remote places on earth, including Antarctica. Nevertheless, the outbreak is illuminating the complexity of responding to infectious disease outbreaks as international cooperation on public health issues has become fractured and contentious, all while global pandemics are only becoming more likely overall. Argentina and neighboring countries in South America endured years of severe drought between 2021 and 2024, including Argentina's worst dry spell in more than 60 years in 2023, followed by.