Hantavirus disease presents with two distinct clinical syndromes depending on which serotype caused the infection. Both share an early flu-like prodrome lasting 3 to 7 days, then diverge sharply: HPS progresses to cardiopulmonary failure; HFRS progresses to renal failure with bleeding. Incubation is 1 to 8 weeks.
Both syndromes begin similarly and are easily mistaken for influenza, COVID-19, viral gastroenteritis, dengue, leptospirosis, scrub typhus, or early sepsis. Typical features per CDC and WHO:
4 to 10 days after symptom onset, HPS rapidly transitions to the cardiopulmonary phase. The defining feature is non-cardiogenic pulmonary oedema with shock. CDC reports overall HPS case-fatality at 38 percent for Sin Nombre virus and 30 to 50 percent for Andes virus. Hallmarks:
HFRS classically progresses through five stages, each lasting hours to days. CFR depends on serotype: Hantaan and Dobrava-Belgrade 5 to 15 percent; Puumala under 1 percent.
| Stage | Features |
|---|---|
| Febrile (days 3–7) | Fever, flushing, conjunctival injection, petechial rash, retro-orbital pain |
| Hypotensive (hours to 2 days) | Vascular leak, shock, tachycardia, oliguria onset |
| Oliguric (days 2–10) | Acute kidney injury, fluid overload, haemorrhagic complications (epistaxis, haematemesis, intracranial bleed in severe cases) |
| Diuretic (days 4 onwards) | Polyuria as renal function recovers; fluid/electrolyte management critical |
| Convalescent (weeks) | Gradual return to baseline; some patients have persistent renal impairment |
Anyone with the prodromal symptoms above plus a credible exposure history — rural rodent contact, recent travel to an endemic area (see country pages), occupational exposure (camping, hunting, conservation, agricultural work, cleaning rodent-infested structures) — should seek urgent medical assessment. Early intensive supportive care, particularly for HPS, is the single strongest predictor of survival. There is no specific antiviral, but ribavirin has shown benefit in early HFRS (less in HPS).
Clinicians evaluating a suspected hantavirus case in 2026 should consider: influenza A and B, COVID-19, viral pneumonia, atypical bacterial pneumonia (Legionella, Mycoplasma), leptospirosis, dengue haemorrhagic fever, scrub typhus, severe sepsis, Plasmodium falciparum malaria, pulmonary embolism, and early HELLP syndrome in pregnancy. The hantavirus blood smear triad (thrombocytopenia, left shift, immunoblasts) plus haemoconcentration is highly suggestive.
Hantavirus Pulmonary Syndrome (HPS) · CFR 30 to 50 percent
Andes virus is the most lethal hantavirus serotype recognised in the Americas. It is endemic to the southern cone of South America and is the primary serotype implicated in the 202…
Read more on ANDV →Hantavirus Pulmonary Syndrome (HPS) · CFR approximately 38 percent
Sin Nombre virus is the principal cause of Hantavirus Pulmonary Syndrome in North America. First identified in 1993 during the Four Corners outbreak, it is carried by the deer mous…
Read more on SNV →Nephropathia Epidemica (mild HFRS) · CFR less than 1 percent
Puumala virus is the most common cause of hantavirus disease in Europe. It produces a milder renal-syndrome variant called nephropathia epidemica and is associated with cyclical ba…
Read more on PUUV →Haemorrhagic Fever with Renal Syndrome (HFRS) · CFR 5 to 15 percent
Hantaan virus is the prototype hantavirus and the most severe cause of HFRS in east Asia. South Korea licences a vaccine (Hantavax) targeting this serotype; no antiviral or vaccine…
Read more on HTNV →Haemorrhagic Fever with Renal Syndrome (HFRS, mild) · CFR 1 to 2 percent
Seoul virus circulates wherever its rat reservoirs do — effectively global. Outbreaks have been reported in pet-rat fanciers in the US and UK and in urban populations near port inf…
Read more on SEOV →Haemorrhagic Fever with Renal Syndrome (HFRS, severe) · CFR 10 to 12 percent
Dobrava-Belgrade virus causes the most severe form of HFRS in Europe, with case fatality rates approaching Hantaan virus levels. It is endemic across the Balkans, Slovenia, and par…
Read more on DOBV →Patients and clinicians frequently ask for a calendar-style view of how hantavirus disease unfolds. The pattern below is based on consolidated CDC, WHO, and ECDC clinical-course descriptions for Hantavirus Pulmonary Syndrome (HPS) caused by Sin Nombre virus and Andes virus, and Haemorrhagic Fever with Renal Syndrome (HFRS) caused by Hantaan, Puumala, and Dobrava-Belgrade virus. Individual courses vary widely.
| Day post-exposure | HPS course | HFRS course |
|---|---|---|
| 0-6 | Asymptomatic incubation. No detectable illness. | Asymptomatic incubation. |
| 7-21 | Possible mild fever in some cases; usually still asymptomatic. | Asymptomatic. Mean incubation 12-21 days. |
| 21-35 | Most patients become symptomatic. Sudden fever >38.5°C, severe muscle pain in thighs and lower back, headache, GI upset. | Febrile phase begins. Headache, fever, abdominal pain, conjunctival haemorrhage, petechial rash. |
| +3 to +5 days from onset | Prodrome continues. Cough may begin. Tachypnoea, mild hypoxia. Blood smear shows thrombocytopenia. | Hypotensive phase: BP crashes, shock risk, oliguria starts. |
| +5 to +10 days from onset | Cardiopulmonary phase. Rapid-onset non-cardiogenic pulmonary oedema, severe hypoxia, circulatory shock. ICU admission essential. Survival depends on early ECMO availability for severe cases. | Oliguric phase: AKI, fluid overload, haemorrhagic complications. Dialysis often required. |
| +10 to +21 days from onset | Convalescence in survivors. Pulmonary function gradually recovers; some patients have persistent restrictive defects. | Diuretic phase, then convalescence. Renal function usually recovers but can leave lasting impairment. |
| Weeks to months | Chronic fatigue, exercise intolerance, mild persistent restrictive lung physiology. Most survivors return to baseline by 6-12 months. | Possible persistent hypertension (Puumala). Most patients recover full renal function. |
Paediatric hantavirus is rare but disproportionately severe when it occurs. CDC case-series data and the Brazilian Ministry of Health 2022 review indicate children under 16 with HPS:
Any child with a febrile illness plus a household exposure to a recently ill adult who travelled to or lives in an ANDV-endemic area (southern Chile, Argentina, Magallanes, Aysén) should be evaluated for hantavirus exposure even if the child has had no direct rodent contact.
The early hantavirus prodrome is virtually indistinguishable from influenza or COVID-19. The key discriminator is the rapid progression to severe pulmonary oedema in HPS, or to oliguria and haemorrhage in HFRS. Use the table below for differential reasoning, but never as a substitute for medical assessment — see hantavirus vs COVID-19 and hantavirus vs influenza for fuller pages.
| Feature | Hantavirus (HPS) | Influenza A/B | COVID-19 | Bacterial pneumonia |
|---|---|---|---|---|
| Incubation | 1-6 weeks | 1-4 days | 2-14 days | 1-3 days |
| Onset | Sudden, severe | Sudden | Gradual to sudden | Gradual |
| Fever | High (39-40°C) | High (38-40°C) | Moderate-high | High |
| Muscle pain | Severe, thighs/back | Diffuse | Variable | Mild |
| GI symptoms | Common, prominent | Occasional | Common in some variants | Rare |
| Cough | Late, with hypoxia | Common, early | Common, dry | Productive, early |
| Thrombocytopenia | Universal | Rare | Mild if any | Rare |
| Mortality | 30-50% (HPS) | <0.1% | ~1% | 5-10% (severe) |
If you have a credible recent exposure (travel to MV Hondius itinerary, rodent-infested cabin/shed cleanout, agricultural work in endemic area) and develop ANY of the following, treat as a medical emergency and call your national emergency number (999 in the UK, 911 in North America, 112 across the EU, 000 in Australia, 131 in Argentina):
Mention hantavirus exposure explicitly when speaking to dispatch. Most emergency medicine clinicians will not consider hantavirus on their initial differential without that prompt.
Most HPS and HFRS survivors return to baseline function over 6-12 months, but persistent sequelae are documented:
See the dedicated questions is hantavirus contagious, hantavirus mortality rate, and hantavirus incubation period for the full answers. Quick versions:
The first symptoms of hantavirus appear 1-8 weeks after exposure and begin with a flu-like prodrome: high-grade fever (39-40°C), severe muscle pain especially in the thighs and lower back, headache, fatigue, nausea, vomiting, and abdominal pain. The prodrome lasts 3-7 days before the disease progresses to either Hantavirus Pulmonary Syndrome (HPS) or Haemorrhagic Fever with Renal Syndrome (HFRS) depending on the strain.
Hantavirus symptoms appear 1-8 weeks after exposure, with most cases becoming symptomatic 2-4 weeks post-exposure. The median incubation period for Sin Nombre virus is approximately 14 days. Andes virus has a slightly longer documented range (7-39 days, median 14). Anyone with a recent credible exposure should self-monitor for up to 45 days to be safe.
Hantavirus prodromal symptoms include severe muscle pain (myalgia) in the thighs, hips, and lower back that patients consistently describe as worse than influenza. Headache and abdominal pain are also common. In the late pulmonary phase of HPS, air hunger and chest tightness are distressing. In HFRS, retro-orbital pain (behind the eyes) and loin pain are characteristic.
The hantavirus haematological triad is: (1) thrombocytopenia (platelet count below 150,000/µL), (2) left-shifted white-cell count, and (3) circulating immunoblasts. When all three are present in a febrile patient with rapid pulmonary deterioration, hantavirus pulmonary syndrome should be the leading diagnosis until ruled out.
Yes. The prodromal symptoms of hantavirus and COVID-19 overlap heavily: fever, fatigue, muscle aches, headache, GI symptoms. The discriminating features that should prompt hantavirus testing are: rapid progression to non-cardiogenic pulmonary oedema with hypotension (HPS); thrombocytopenia on bloods; relevant exposure history (rodent contact, travel to endemic area, MV Hondius itinerary). HORIZON's symptom-comparison page covers this in detail.
Hantavirus infection can produce a subclinical or mild flu-like illness that resolves without diagnosis, particularly for Puumala virus (PUUV) which has a case-fatality rate under 1% and includes a substantial fraction of mild and asymptomatic infections. For Sin Nombre and Andes virus, clinically apparent infection is almost always severe.
Paediatric hantavirus infection is rare but disproportionately severe. Children present with the same prodrome but often more prominent GI symptoms that can be mistaken for appendicitis or gastroenteritis. Progression to the cardiopulmonary phase is typically faster than in adults (median day 3 vs day 5), and mortality has historically been higher in some case series due to lower cardiac reserve and delayed recognition.
HPS rarely causes a rash. HFRS classically presents with petechiae (small red-purple haemorrhagic spots) on the soft palate, in the axillae, and across the chest, alongside conjunctival injection that appears as marked redness of the eye whites. The petechial rash is a key clinical sign supporting HFRS over other tropical febrile illnesses.
Call 999 (UK), 911 (US/Canada), 112 (EU), 000 (Australia), or 131 (Argentina) if you have credible recent exposure plus any of: shortness of breath, chest tightness, confusion, blue or grey lips/fingertips, inability to keep fluids down with fever, unexplained bleeding, or a sharp drop in urine output. Always mention hantavirus exposure explicitly to dispatch.
Most HPS and HFRS survivors return to baseline function over 6-12 months. Persistent sequelae are documented: reduced pulmonary diffusing capacity (DLCO) after HPS, minor proteinuria after HFRS, and post-ICU fatigue or psychological symptoms in 20-30% of severe cases. Puumala-virus HFRS has been linked to long-term hypertension in some Scandinavian cohorts.