Argentina hantavirus outbreak 2026 records highest fatality rate
Argentina has reported 45 confirmed hantavirus cases in 2026, the highest number since systematic surveillance began. The disease has caused 33 deaths, a 31.4% case‑fatality rate—the most lethal season in recent history.
Cases are concentrated in Buenos Aires, Salta, Santa Fe, Jujuy, Río Negro, Entre Ríos and Chubut. Buenos Aires accounts for about half of the deaths, while Salta shows the highest incidence. The majority of patients are men aged 20‑49, with a median age of 36.
The outbreak was amplified by the Andes variant, the only hantavirus strain that spreads between people via respiratory droplets. A notable cluster occurred on the cruise ship MV Hondius, which left Ushuaia on 1 April with 147 passengers and crew from 23 nationalities; eight infections and three deaths were linked to the ship. The World Health Organization issued an alert, and the Argentine Institute Malbrán dispatched teams to Tierra del Fuego to capture rodents and collect samples under strict biosafety protocols.
In the rural and peri‑urban areas of Buenos Aires province, 18 cases and seven deaths have been confirmed, prompting local health authorities to warn of continued transmission beyond the usual seasonal window.