Hantavirus explained: the old rodent virus behind the Dutch cruise ship cases

A scary virus story is easier to understand when you start in the right place.

Do not start on a cruise ship. Do not start in the Netherlands. Do not even start in 2026.

The story of hantavirus begins much earlier. It involves soldiers, field mice and an illness that puzzled doctors for decades.

The virus now in the news is linked to the m/v Hondius. This is a Dutch-flagged cruise ship. Passengers became very sick during a voyage. The trip began in Ushuaia, Argentina.

The World Health Organization (WHO) shared an update on 7 May 2026. They reported eight cases and three deaths. Five cases were confirmed as hantavirus.

The strain is Andes virus. This type is found in South America. It is unusual. Rare human-to-human spread can happen. This usually requires close and long contact.

That sounds alarming. It is a serious issue. But it is not a new pandemic.

What is hantavirus?

Rodents carry hantaviruses. These include mice, rats and voles. People get sick when they breathe in dirty dust. This dust holds urine, droppings or saliva from infected rodents.

The word “hantavirus” is not one disease. It is a virus family. Different types cause different illnesses.

Some types are common in Europe and Asia. They affect the kidneys. Other types in the Americas cause severe lung and heart disease. Andes virus is in this severe group.

The U.S. Centers for Disease Control and Prevention (CDC) explains more. Andes virus causes a severe lung illness. This is called hantavirus pulmonary syndrome. It is the only hantavirus known to spread between people. But this spread needs close contact with a sick person.

Where did hantavirus come from?

The name comes from the Hantan River in Korea.

Thousands of United Nations troops got sick during the Korean War. They had a strange illness. It caused fever, bleeding and kidney failure. Doctors called it Korean haemorrhagic fever.

The disease is likely much older. But modern science stepped in here. It started with soldiers and rodents near Korean fields.

In the 1970s, Korean virologist Ho Wang Lee and his team found the virus. They named it after the Hantan River. This gave the whole virus family its name: hantavirus.

So no, hantavirus is not new. But where and how it appears can be new.

The second shock: healthy people dying in the US

For a long time, hantaviruses were linked to Europe and Asia. They caused kidney disease there.

Then came 1993.

Doctors saw something scary in the US. This was in the Four Corners region. Young, healthy people got flu-like symptoms. Then they collapsed with severe breathing problems.

Investigators found the cause. It was a new hantavirus. Deer mice carried it. Scientists later named it Sin Nombre virus.

That outbreak changed science. It showed American hantaviruses could cause different problems. They could cause hantavirus pulmonary syndrome.

It also taught us a lesson. Outbreaks often start when humans disturb rodent spaces.

Andes virus: the South American strain

The virus on the Hondius is not Sin Nombre virus. It is Andes virus.

Andes virus lives in South America. It is common in Argentina and Chile. It causes severe lung and heart illness.

Wild rodents carry it. People catch it from infected rodents or dirty spaces.

Andes virus is special. It has one rare feature. It can spread from person to person.

But it does not spread like flu or COVID-19. You do not catch it easily in a shop or train. The CDC lists the real risks. These include direct physical contact. Spending long times in closed spaces is another risk. Contact with body fluids also spreads it.

This is why authorities trace close contacts. They are not telling the public to panic.

So what happened on the Hondius?

The exact chain of infection is still unknown. We know some details. We lack others.

The WHO said the ship left Ushuaia, Argentina, on 1 April 2026. It sailed through the remote South Atlantic. The WHO noted the first two cases travelled in South America first. This included Argentina.

The RIVM (National Institute for Public Health and the Environment) is the Dutch health agency. They tested the virus. Lab research showed it was the Andes variant.

This gives experts a big clue.

The most likely starting point is South America. Andes virus lives in rodents there. Exposure could have happened before boarding. It could have happened during travel or in a dirty space.

Once infected people boarded, the risk changed. Did they pass it to other passengers?

A cruise ship is a closed space. People eat and travel together. They sleep in cabins. They share spaces for weeks.

A virus has more chances to spread here. It just needs close contact.

Is it the same as hantavirus in the Netherlands?

No.

The Netherlands has hantaviruses. But they are different types. The RIVM lists Puumala virus, Seoul virus and Tula virus. These occur in the Netherlands.

Bank voles, rats and field voles carry them. The RIVM says Dutch infections are rare. Puumala is the most common local type.

Andes virus is very different. It comes from the Americas. It causes worse disease.

This detail matters. A Dutch ship does not mean a Dutch virus. The strain points straight to South America.

What symptoms does it cause?

The illness starts like a normal flu.

Early signs include fever, headache and muscle pain. People also report back pain, nausea and vomiting. Diarrhoea, cough and chest pain are common. Patients lose their appetite and struggle to breathe.

The CDC says symptoms take time to show. They appear 4 to 42 days after exposure.

This delay makes tracing hard. A person might feel fine for weeks.

Severe cases get worse fast. Flu symptoms turn into breathing trouble. Anyone with exposure and symptoms must call a doctor. This article is not medical advice. Do not use it to self-diagnose.

Does it spread before symptoms?

This is a vital question.

The CDC says people are normally infectious only when showing symptoms.

That fact changes the public risk. Viruses that spread silently are hard to stop. Andes virus is not like COVID-19.

Doctors only worry about sick cases and close contacts.

Why health officials are tracing contacts

Contact tracing looks scary. It makes people fear a big outbreak.

But tracing is just smart safety.

The WHO calls the ship cases serious. But they say the public risk is low. The European Centre for Disease Prevention and Control (ECDC) agrees. They say the risk in Europe is very low. People just need to follow basic safety rules.

In the Netherlands, the RIVM monitors contacts. This does not mean everyone is at risk. Only people with real exposure are watched.

Should people in the Netherlands worry?

Most people can relax. The public risk is low for three reasons.

First, Andes virus does not live in the Netherlands. It stays in the Americas.

Second, the RIVM tested three people on 8 May 2026. They had symptoms after flying with an infected person. All three tested negative for Andes virus.

Third, human spread is very rare. It mostly needs close contact with a sick person.

The event is tragic for the victims. But there is no reason for general panic.

How do people get infected?

The main danger is not a person. It is a dirty space.

People get sick by breathing in tiny particles. These come from dry rodent urine, droppings or saliva. This happens when you sweep a shed. It happens when you open a closed cabin. Cleaning a barn or moving nests can also release dust.

This is why safety focuses on cleaning methods. It is not about wearing masks in the street.

How to reduce risk

Are you cleaning a shed, garage or cabin? Do not sweep or vacuum first.

Open the windows. Wear gloves. Wet the dirty areas before wiping them. Disinfect the space. Throw away waste safely. Do not stir up dust.

The RIVM gives the same advice. Open closed rooms. Do not dry sweep droppings. Use wet cloths.

The rule is simple. Watch out for rodents first. Watch out for close contact second.

The real lesson from the Hondius case

This story is not about a brand-new virus.

It is about an old virus family. It is about a tough South American strain. It shows the risks of travel and cruise ships.

The virus has a long history. It includes the 1950s Korean War and the 1993 US outbreak. Now it includes a Dutch ship in the South Atlantic.

This history stops us from learning the wrong lesson.

The wrong lesson is: a new pandemic is here.

The right lesson is different. Rare animal viruses travel with people. Most do not spread easily. But they can cause big problems in the wrong place. A remote ship is a tough place for an outbreak.

Hantavirus is old. The ship cases are new. The general risk is low. But health workers must act fast and with care.