In the 2025–2026 epidemiological season, Argentina has confirmed 101 cases of hantavirus infection, of which 32 have been fatal, the country’s Health Ministry said. The fatality rate has exceeded 31%, and case numbers are already significantly higher than in previous years. Authorities said case counts have remained above the epidemic threshold for most of the season. Since the start of 2026 alone, 42 new infections have been recorded, local news outlet Infobae reported.
According to the Pan American Health Organization (PAHO/WHO), Argentina now has the highest number of hantavirus infections in the Americas.
Hantavirus is primarily transmitted through inhalation of aerosols containing the excreta of infected rodents. In Argentina, circulating strains include Orthohantavirus andesense and Orthohantavirus mamorense, both associated with severe cardiopulmonary syndrome, health officials said. The Health Ministry also cautioned that in some cases – particularly with the Andes strain – human-to-human transmission has been documented.
The highest incidence has been recorded among men aged 20 to 49, with the highest mortality rate in the 20–29 age group, authorities said. Experts attribute the rise in cases to increased human contact with natural areas, climate change, destruction of animal habitats and the migration of rodent carriers.
The situation drew additional attention following reports of an outbreak aboard the international cruise ship MV Hondius. The World Health Organization has already launched an investigation.
On May 7, countries around the world took emergency measures to prevent further spread of hantavirus following the cruise ship outbreak, tracing passengers who had already disembarked before the virus was detected and anyone who had close contact with them afterwards. Experts stressed that infections remain extremely rare, but the outbreak has put health authorities on high alert.
The hantavirus outbreak investigation comes amid unresolved international negotiations. Earlier, WHO member states extended discussions on pathogen‑sharing rules that were supposed to take effect alongside a pandemic treaty adopted in 2025. Without approval of these rules, the treaty cannot enter into force.
