Argentina has confirmed 101 hantavirus infections during the 2025–2026 epidemiological season, nearly double the 57 cases recorded over the same period last year, the country’s health ministry reported this week. The surge, which has resulted in 32 deaths and a fatality rate exceeding 31%, marks the highest infection count since 2018 and has placed Argentina well above the epidemic threshold for most of the season.
The spike comes as global attention has turned to a separate hantavirus outbreak aboard the cruise ship MV Hondius, which departed from Ushuaia in southern Argentina on April 1 and has since been linked to eight cases and three deaths, according to the World Health Organization.
Climate Change Fuels Rodent Spread
Health officials and researchers attribute the domestic surge largely to climate change and habitat destruction, which are enabling the long-tailed mouse — the primary carrier of the virus in Argentina and Chile — to expand into previously unaffected areas. Rising temperatures are reshaping ecosystems across the country, and extreme weather events including droughts, intense rainfall, and forest fires are pushing both humans and wildlife into new territories.
“Argentina is becoming more tropical due to climate change, leading to disruptions such as dengue and yellow fever, as well as the emergence of new tropical plants that provide food sources for mice to thrive,” Hugo Pizzi, a prominent Argentine infectious disease expert, told The Associated Press.
Roberto Debbag, vice president of the Latin American Society of Vaccinology, warned that tourism is also contributing to the risk. “Anyone going to a risk area for tourism, if it is not cleared of undergrowth, represents a very high danger,” he said.
Cases Shift Beyond Traditional Hotspots
While hantavirus in Argentina has historically concentrated in rural and peri-urban settings in the country’s northwest, this season has seen a geographic shift. The province of Buenos Aires alone has recorded 42 cases, the highest in the country, with the central region now bearing the brunt of the outbreak. At least one confirmed case in Río Negro province was found outside historically endemic areas, signaling the virus’s expanding reach.
The Argentine health ministry noted that “increasing human interaction with wild environments, habitat destruction, the establishment of small urbanizations in rural areas, and the effects of climate change contribute to the appearance of cases outside historically endemic areas”. According to the Pan American Health Organization, Argentina now has the highest number of hantavirus infections in the Americas.
