What is hantavirus: symptoms, transmission, treatment and risks
Public health editor
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Hantavirus is not a single virus but a whole family of them. Scientists first identified it during the Korean War in the 1950s. More than 3,000 UN soldiers fell ill with a mysterious hemorrhagic fever at that time.
The name comes from the Hantan River in Korea. That is where researchers first isolated the pathogen. But real worldwide attention came only in May 2026, after the cruise ship outbreak.
Types of hantaviruses
Scientists divide hantaviruses into two large groups based on geography. Old World strains live in Asia and Europe. New World strains are found in North and South America.
This division also determines the type of illness. Old World strains cause hemorrhagic fever with renal syndrome. Simply put, they attack the kidneys.
New World strains cause hantavirus pulmonary syndrome. This is far more dangerous — the virus destroys the lungs. A person literally suffocates as the blood vessels in the lungs stop working properly.
Major hantavirus strains
| Strain | Region | Disease type | Fatality rate | Human-to-human spread |
|---|---|---|---|---|
| Hantaan | Asia, Far East | Renal syndrome | 1-15% | No |
| Puumala | Europe, Russia | Renal syndrome | Below 1% | No |
| Seoul | Worldwide | Renal syndrome | 1-2% | No |
| Sin Nombre | North America | Pulmonary syndrome | 30-40% | No |
| Andes | South America | Pulmonary syndrome | 30-50% | Yes (rare) |
The Andes strain is unique. It is the only hantavirus capable of spreading between people. That is the strain found on the MV Hondius cruise ship in May 2026.
Symptoms of hantavirus in humans
Early signs can easily be mistaken for ordinary flu. A person develops fever, headache and muscle aches. Sometimes nausea or abdominal pain also appears.
But then the picture changes sharply. In the pulmonary form, shortness of breath can intensify within hours. Breathing becomes difficult, blood pressure drops. Without emergency hospital care, the situation can become critical very quickly.
The renal form develops more slowly. Lower back pain is added to the symptoms. Then urine output drops sharply — a signal that the kidneys are struggling.
How to tell hantavirus apart from flu and COVID-19
| Symptom | Hantavirus | Flu | COVID-19 |
|---|---|---|---|
| Fever | Yes | Yes | Yes |
| Cough | Late stage | Common | Common |
| Shortness of breath | Rapidly worsens | Rare | Possible |
| Lower back pain | Yes (renal form) | No | No |
| Loss of smell | No | No | Common |
How hantavirus spreads
The main source of infection is rodents. The virus lives in mice and voles without harming them. But a person only needs to inhale dust containing particles of their urine or droppings.
That is why farmers, campers and cabin owners are at the highest risk. They have more frequent contact with rodent habitats.
Person-to-person transmission is extremely rare. It is only possible with the Andes strain. And even then, doctors say it requires close and prolonged contact — for example, within a family or in a hospital room.
Transmission routes
| Route | Frequency | Conditions |
|---|---|---|
| Inhaling dust with rodent waste | Main route | Cleaning, farm work |
| Rodent bite | Rare | Direct contact |
| Human-to-human (Andes) | Very rare | Close prolonged contact |
| Contaminated surfaces | Possible | Surface contact |
Treatment and vaccines
There is no specific antiviral drug for hantavirus. There is also no commercial vaccine — though research is underway in the United States, Canada and China. All of it remains in early stages.
Treatment is supportive. In the pulmonary form, patients receive oxygen and may need mechanical ventilation. In the renal form, doctors manage fluid balance and may use dialysis when necessary.
The key rule is simple — the sooner hospital treatment begins, the higher the chances of survival. That is why anyone with suspected exposure to rodents should seek medical attention immediately.
How dangerous is hantavirus
The fatality rate depends on the strain and how quickly treatment starts. The mildest strain is Puumala — less than 1 percent. The most severe is Andes — up to 50 percent without treatment.
But context matters. Hantavirus infections are rare — about 150,000 to 200,000 cases are recorded worldwide each year. The vast majority are renal syndrome cases in Asia and Europe.
For an ordinary urban resident who does not handle rodents, the risk is essentially zero. Both WHO and CDC assess the global threat as low.
- Annual renal syndrome cases worldwide — 150,000-200,000
- Annual pulmonary syndrome cases — around 300 (Americas)
- Fatality rate for renal syndrome — 1-15%
- Fatality rate for pulmonary syndrome — 30-50%
- No vaccine, no specific antiviral treatment
Sources
- WHO: who.int/health-topics/hantavirus
- CDC: cdc.gov/hantavirus
- ECDC: ecdc.europa.eu/en/hantavirus-infection
- NIH: ncbi.nlm.nih.gov/books/NBK560682
- CDC Andes outbreak summary: cdc.gov/hantavirus/situation-summary