What is the mortality rate of hantavirus?

Mortality varies sharply by virus species. Andes virus and Sin Nombre virus, which cause hantavirus pulmonary syndrome (HPS), have a case fatality rate (CFR) of 30-40%. The Eurasian variants causing hemorrhagic fever with renal syndrome (HFRS) — Puumala, Hantaan, Seoul — have lower CFR: Puumala 0.1-1%, Seoul ~1-2%, Hantaan 5-15%. The MV Hondius cluster involves Andes virus, the most lethal strain. Of the 8 cases reported as of 7 May 2026, 3 have died — a 37.5% case fatality rate consistent with historical Andes virus statistics. There is no specific antiviral treatment; supportive intensive care (oxygen, ventilation, ECMO) is the standard of care and improves outcomes when initiated early.