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

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. 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. 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.

The good news is that the Andes Hantavirus, while uniquely deadly, is likely nowhere nearly as transmissible as COVID-19. 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. 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.

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. 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. 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. Grist is the only award-winning newsroom focused on exploring equitable solutions to climate change.

A complex web of natural and human-made 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. The viruses infect people via rodent waste, often through the inhalation of dust containing trace amounts of the excreta.