Hantavirus Death Rate — Case-Fatality by Strain
Hantavirus case-fatality rate (CFR) varies dramatically by strain. The most lethal strains kill 30-50% of confirmed cases; the mildest kill under 1%. This page summarises the CFR data, explains why outcomes vary so widely, and lists the factors that most affect survival.
Case-fatality rate by serotype
| Serotype | Syndrome | Case-fatality rate | Survival rate | Key factor |
|---|---|---|---|---|
| Sin Nombre (SNV) | HPS | 36-38% | 62-64% | Early ICU, ECMO availability |
| Andes (ANDV) | HPS | 30-50% | 50-70% | ECMO halves mortality |
| Hantaan (HTNV) | HFRS (severe) | 5-15% | 85-95% | Early ribavirin, dialysis |
| Dobrava-Belgrade (DOBV) | HFRS (severe) | 5-12% | 88-95% | Bleeding control, dialysis |
| Bayou (BAYV) | HPS | ~33% | ~67% | Sporadic cases, regional |
| Laguna Negra (LANV) | HPS | ~12% | ~88% | Mostly mild presentations |
| Choclo (CHOV) | HPS (mild) | ~10% | ~90% | Generally less severe HPS |
| Puumala (PUUV) | HFRS (mild) | <1% | >99% | Self-limiting in most |
| Seoul (SEOV) | HFRS (mild) | <1% | >99% | Mild course |
| Tula (TULV) | HFRS (mild, rare) | <1% | >99% | Rare clinical cases |
What determines hantavirus mortality
Mortality varies among patients infected with the same strain. The factors with the strongest evidence:
- Time to ICU admission. Every hour of delay increases mortality. Patients admitted before respiratory symptoms have substantially better outcomes than those admitted after.
- ECMO availability. Cohort studies from Chile, Argentina, and the USA show veno-venous ECMO halves HPS mortality in patients with refractory hypoxia.
- Fluid management. Aggressive crystalloid resuscitation worsens non-cardiogenic pulmonary oedema. Restrictive fluids plus vasopressor-first haemodynamic support is now standard.
- Age. Older patients have higher mortality, partly due to lower cardiac reserve.
- Pre-existing conditions. Hypertension, diabetes, and chronic kidney disease increase HFRS mortality. Chronic lung disease increases HPS mortality.
- Strain. See the table above — strain choice dominates all other prognostic factors.
- Time from symptom onset to diagnosis. Misdiagnosis as influenza, COVID-19, atypical pneumonia, or appendicitis delays treatment and worsens outcomes.
Hantavirus death rate compared to other diseases
| Disease | Case-fatality rate (typical) |
|---|---|
| Rabies (untreated) | ~100% |
| Ebola virus disease (untreated) | 40-90% |
| Andes virus HPS | 30-50% |
| Sin Nombre virus HPS | 36-38% |
| Untreated MERS | ~35% |
| SARS (original) | ~10% |
| Hantaan virus HFRS | 5-15% |
| Yellow fever (severe form) | 20-50% |
| Influenza H5N1 (human) | ~50% |
| COVID-19 (Omicron era) | ~0.1-1% |
| Puumala virus HFRS | <1% |
| Seasonal influenza | <0.1% |
Global hantavirus deaths per year
Estimating global hantavirus mortality is hampered by underreporting in some regions, particularly Russia and rural China. Best-available figures:
- China: 200-500 deaths per year (mostly Hantaan HFRS).
- Russia: 50-200 deaths per year (Puumala-dominant in European Russia; Hantaan in the Far East).
- South Korea: 5-15 deaths per year (Hantavax has reduced this substantially).
- Americas total: 200-400 deaths per year combining HPS in the USA, Mexico, Argentina, Chile, Brazil, Paraguay, Bolivia.
- Europe total: 5-30 deaths per year (Puumala is mild; DOBV more severe but localised).
- Global total estimate: 500-1,200 deaths per year.
How HORIZON tracks hantavirus mortality
Every authoritative-source update (WHO DON, ECDC CDTR, PAHO, national ministry) is ingested every 15 minutes. Death counts are surfaced on the homepage and per-country and per-incident pages, with the source's NATO Admiralty Scale reliability rating visible. The open dataset exposes the full historical series under CC BY 4.0.
Open the live hantavirus outbreak map →
Frequently asked questions
What is the death rate for hantavirus?
Case-fatality varies sharply by strain. Sin Nombre virus HPS: 36-38%. Andes virus HPS: 30-50%. Puumala virus HFRS: under 1%. Hantaan virus HFRS: 5-15%. Seoul virus HFRS: under 1%. Dobrava-Belgrade virus HFRS: 5-12%. The dominant strain in the 2026 MV Hondius outbreak is Andes virus.
How deadly is the MV Hondius hantavirus outbreak?
The MV Hondius cluster involves Andes virus, with case-fatality rate of 30-50%. Live outcome data is tracked on the incident page. Survival is strongly dependent on early ICU admission and access to ECMO for severe cases.
Is hantavirus the deadliest virus in the world?
Hantavirus is not the deadliest — Ebola virus, rabies (untreated), Nipah virus, and Marburg virus all have higher case-fatality rates in untreated patients. But hantavirus has the highest case-fatality rate among viruses currently active in the Americas, and the highest of any virus regularly encountered by travellers in Patagonia or the US Southwest.
Why does Andes virus kill so many people?
Andes virus deteriorates rapidly: 12-48 hours from cough to respiratory failure. The pulmonary oedema is non-cardiogenic and capillary-leak driven, which means aggressive fluid resuscitation makes it worse. Without early ICU admission and ideally ECMO, survival is poor. Case-fatality drops substantially in centres with ECMO capacity.
How does hantavirus mortality compare to COVID-19?
Hantavirus Pulmonary Syndrome has 30-50% case-fatality. COVID-19 has approximately 1% case-fatality overall (varies by age and variant). Hantavirus is roughly 30-50x more lethal per case but vastly less common — global hantavirus deaths per year are in the low thousands; COVID-19 global deaths peaked in the millions.
Has the hantavirus death rate changed over time?
Yes — modestly. Earlier outbreaks (Four Corners 1993) had higher case-fatality (~50%) because the disease was unrecognised and ICU strategies hadn't been adapted. Modern care with restrictive fluids, lung-protective ventilation, vasopressor-first haemodynamic support, and ECMO has reduced SNV HPS case-fatality to 36-38%. ECMO availability is the single biggest modifiable factor.
What proportion of hantavirus deaths occur before hospital admission?
About 15-25% of fatal HPS cases die before reaching definitive critical care. The pre-hospital deaths are largely driven by misdiagnosis (atypical pneumonia, influenza, COVID-19) and rapid deterioration during the prodromal phase. Cases identified and admitted early to ICU have substantially better outcomes.
Do hantavirus survivors fully recover?
Most do, but not all. About 70-80% return to baseline function over 6-12 months. The remainder have persistent pulmonary function reduction (HPS), proteinuria or hypertension (HFRS), exercise intolerance, or post-ICU psychological symptoms. Pulmonary rehabilitation can recover most of the deficit.
Which country has the lowest hantavirus death rate?
Finland and Sweden — because their dominant strain is Puumala virus (HFRS with case-fatality under 1%). South Korea also has low mortality because of the Hantavax vaccine programme in agricultural workers.
Is hantavirus 100% fatal if untreated?
No. Even untreated hantavirus disease has variable outcomes depending on serotype and host. Puumala HFRS resolves spontaneously in most patients with no specific treatment. Sin Nombre and Andes HPS have ~40-60% mortality even without treatment. With modern intensive care, mortality drops by half or more.