Current information about the hantavirus

What types of hantaviruses are present in the Netherlands?

In the Netherlands, there are 3 types of hantaviruses that can cause disease in humans. These are transmitted to humans by different species of rodents:

• Puumala virus: transmitted by bank voles.
• Seoul virus: transmitted by wild or pet rats.
• Tula virus: transmitted by field voles.

How do I recognise hantavirus?

Most people do not become ill from the 3 hantaviruses that occur in the Netherlands. In 90% of cases, people do not develop symptoms. When someone does get ill, symptoms are often flu-like. The severity of symptoms can vary by virus and individual.

In the Netherlands, Puumala virus infection is the most common. Usually, people do not get ill from this virus. If people do get ill, the symptoms are usually mild, such as:

• muscle pain
• headache
• fever
• nausea

Sometimes, people get more severe symptoms. In those cases, the kidneys or liver can become slightly inflamed. A person may then suffer from:

• high fever
• vomiting
• pain in the abdomen and sides
• poor vision

The Seoul virus also does not usually make people ill, or they get mild, flu-like symptoms. In rare cases, more serious symptoms may occur, such as liver inflammation, weakened muscles in the legs and lower back pain. In very rare cases, the Seoul virus can lead to kidney failure or fever with internal bleeding.

Little is known about the Tula virus in humans. There is only one known case, a 12-year-old boy in Switzerland who was bitten by a rodent. He suffered from fever, nail disease and skin rash.

Some hantaviruses have a more severe disease course

In the rest of Europe, other hantaviruses also occur. In most cases, these cause similar symptoms. A variant that occurs in the Balkan countries (the Dobrava virus) often causes a more severe disease progression. The mortality rate from hantaviruses in Europe is very low (less than 1%).

How do I get a hantavirus infection?

Hantaviruses are spread by rodents. They do not get sick themselves, but they can infect other rodents and humans. Even rodents that look healthy may carry the virus. The viruses are in the faeces, urine and saliva of infected rodents. The viruses can survive there for 2 weeks, even when the faeces, urine or saliva have dried up. Dried material can form dust particles (aerosols) that can become airborne. When people inhale these dust particles, they can contract the virus. This can happen when someone sweeps the floor in a barn, but also in (or near) a forest, field, camping site or garden.

People can also contract the virus through a bite from an infected rodent or from eating food contaminated by rodents.

The time between getting infected and getting ill varies by type of virus and can take between a few days to 60 days. The incubation period is usually 2 to 4 weeks.
Have you had a hantavirus infection? In that case, you will have built up antibodies for the type of hantavirus that made you ill. You can still contract other types of hantavirus.

Is the hantavirus transmissible from human to human?

The hantaviruses found in Europe and Asia cannot be transmitted from person to person. This also applies to most hantaviruses in North and South America.

There are indications that it may be possible for the Andes virus to be transmitted from person to person. There are only a few examples of this. Moreover, this only happens when people have very close contact with each other.

Who can become ill from a hantavirus?

Anyone can catch a hantavirus, although the chance of that is very small. Some people are more likely to get ill from a hantavirus:

• people who work in the forest or live near a forest or fields, and farmers
• people who enter a room where there are or have been a lot of mice or rats. For example, old houses, barns or holiday homes that have not been used for a while.
• People who keep rats or often come into contact with wild or pet rats.
• People who professionally have a lot of contact with rats and mice or their urine/faeces are more likely to get ill. They are subject to additional measures to prevent disease: See: Cautions when working with wild, live rats (in Dutch).

Adults become ill or sometimes very ill from hantavirus infections more often than children.

How do I prevent myself from getting a hantavirus infection?

There is no vaccination against hantaviruses.

You can prevent hantavirus infections by avoiding rodents and their hiding places. Always store food waste properly, for example in closed containers, to prevent pests from accessing the food.

In rooms that have been closed for a long time, mice and rats may have created nests. You must ventilate these areas well. Open the windows and doors for at least half an hour and leave the room yourself.

If you do find mice or rat nests, droppings or dead rats or mice in the home, you should remove everything with a wet cloth, put it in a rubbish sack and tie it up. This rubbish sack can be disposed of with the household waste. Always wear gloves when touching dead animals, droppings or nest residues.

After you remove everything, clean the area thoroughly with soap and water. Then disinfect the site thoroughly with a solution of 250 ml of bleach in 10 litres of water. Let it soak in for 5 minutes and then rinse it with water.

It is best to wet nests, droppings and dead animals found outside before removing them.

Caution: never use a vacuum cleaner or broom to clean up nests, droppings or dead animals. This can cause the dust to become airborne, allowing the virus to spread.

Can hantavirus be treated?

People with hantavirus infections usually recover completely by themselves. This may take several weeks. If the kidneys stop working properly, hospitalisation is required.

How common is hantavirus in the Netherlands?

Hantaviruses are found all over the world. The types that occur in Europe cause hundreds of patients a year. In the Netherlands, hantavirus infection is diagnosed occasionally. The types of hantaviruses found in the Netherlands are Puumala virus, Tula virus and Seoul virus. The Puumala virus is the most common and causes most cases in patients. As a rule, Puumala virus infections do not usually cause any symptoms. Only 1 in 10 infected people gets symptoms. The disease course is relatively mild. Often, patients only experience flu-like symptoms (muscle pain, headache, fever, nausea) but a hantavirus infection can also be more severe. In case of acute kidney failure, hospitalisation is necessary.

Can a person with hantavirus go to childcare, school or work?

The Andes virus (a type of hantavirus) can be transmitted from person to person during prolonged and close contact. People who are (possibly) infected with the Andes virus should therefore not have contact with other persons.

The risk of people infecting each other with any of the other hantaviruses, such as Puumala virus, Tula virus or Seoul virus, is negligible. Someone with a hantavirus infection caused by any of these particular hantaviruses can, if they feel well, go to work, childcare or school.