Hantavirus Survival Rate by Age — What the Published HPS Mortality Data Actually Show

The clearest evidence-based summary of hantavirus mortality across age groups, what changes the curve, and how the 2026 MV Hondius cluster is being managed inside this framework.

The Short Answer

Hantavirus pulmonary syndrome (HPS) in the Americas has an overall case-fatality rate of roughly 36%, according to published CDC surveillance data, which translates to an overall survival rate of about 64%. Andes virus outbreaks specifically in southern Argentina and Chile have historically reported case-fatality rates between 35% and 50%. By contrast, the Old World hantaviral syndrome — haemorrhagic fever with renal syndrome (HFRS), caused by Hantaan, Seoul, Puumala, and Dobrava viruses — has a much lower case-fatality rate, generally between 1% and 15% depending on the strain. The headline numbers conceal real variation by age, comorbidity, time-to-care, and access to advanced critical care including extracorporeal membrane oxygenation (ECMO).

HPS Survival Rate by Age Group (Published US and South American Series)

These approximate ranges synthesise CDC HPS surveillance summaries and published Andes virus cohort studies from Argentina and Chile. They should be read as rough benchmarks rather than precise estimates; the published confidence intervals around each number are wide because the underlying case counts are small.

Why Age Matters Less Than You Might Expect

For many infectious diseases — influenza, COVID-19, RSV — age is by far the dominant predictor of outcome. For hantavirus pulmonary syndrome, age matters but is not the dominant predictor. The dominant predictors are time from symptom onset to ICU-level care and access to mechanical ventilation and ECMO at a tertiary centre. A 70-year-old with comorbid heart disease who reaches an ECMO-capable centre within 24 hours of cardiopulmonary deterioration may have a better outcome than a 30-year-old who deteriorates at home in a rural area without immediate access to intensive care. This is why the WHO response to the 2026 MV Hondius cluster placed so much weight on getting passengers to ECMO-capable centres in Paris, Madrid, Atlanta, the Netherlands, Geneva, and Nebraska before any clinical conversion.

What ECMO Changes in the Curve

The most-cited Chilean Andes virus cohort reports survival on ECMO for severe HPS approaching 60%, compared with the 35-50% all-comers Andes virus case-fatality rate. The intuition is straightforward: the underlying pathology in HPS is a short-lived capillary leak that lasts four to seven days, and ECMO supports oxygenation and circulation through that window without the lung-injuring high airway pressures that conventional mechanical ventilation requires at this severity. Patients who reach ECMO before refractory shock develops do markedly better than those put on the circuit after several days of high-pressure ventilation. None of this changes the underlying virology; it changes the survival curve by buying time for the immune system to clear the virus.

The Andes Virus Versus North American Hantavirus Question

Sin Nombre virus, the dominant North American HPS-causing hantavirus, and Andes virus, the South American strain at the centre of the 2026 MV Hondius cluster, have broadly similar case-fatality rates in the published literature. Andes virus is unique because it is the only hantavirus species in which limited human-to-human transmission has been documented under conditions of close prolonged contact. That epidemiological feature does not appear to change the per-case severity once infection is established; the survival curves for symptomatic Andes virus HPS and symptomatic Sin Nombre virus HPS look similar at large enough sample sizes.

HFRS Survival Rates: A Different Disease, A Different Curve

The Eurasian hantaviruses — Hantaan, Seoul, Puumala, and Dobrava — cause a clinically different syndrome called haemorrhagic fever with renal syndrome (HFRS) rather than the pulmonary syndrome of New World hantaviruses. HFRS has substantially better survival overall. Puumala virus, common in Scandinavia, has a case-fatality rate often quoted under 1%. Seoul virus is roughly 1-2%. Hantaan virus in East Asia is more severe, with case-fatality rates historically between 5% and 15%. Dobrava virus in the Balkans is similar. The licensed Korean Hantavax vaccine targets Hantaan and Seoul virus and is not relevant to Andes virus or the Americas.

What This Means for the MV Hondius Cohort

The 11 published MV Hondius cases (as of WHO DON601, 13 May 2026) range across ages 30 to 70 and include both healthy passengers and individuals with comorbid disease, the most notable being the French woman in her 60s with asthma now on ECMO at Bichat Hospital in Paris. With three confirmed and probable deaths against 11 cases, the cluster's case-fatality rate of approximately 27% is, if anything, slightly below the historical Andes virus average — though the denominator is small and the situation is still evolving inside the WHO 42-day active monitoring window. The factor that has most clearly improved outcomes for this cluster is rapid recognition and triage to ECMO-capable centres at the time of disembarkation, exactly the operational pattern the published survival data would predict.

Reading Survival Rates Honestly

A case-fatality rate is a population statistic, not an individual prognosis. Two patients with the same age and the same strain can have very different outcomes based on time-to-care, baseline cardiopulmonary reserve, and the experience of the receiving centre. For an individual exposed to hantavirus, the right framing is not the population CFR but the personal action plan: know the prodromal symptoms, present urgently if they appear, name the suspicion at triage, and accept rapid escalation to an ICU at the first sign of respiratory or haemodynamic deterioration.