Therefore, you can infect others without getting sick.

Many people think it sounds strange. How can you infect others when you don’t have symptoms yourself? Here are nine questions and answers about asymptomatic infection.

Didrik F. Vestrheim is Chief Physician in the Department of Vaccine and Infection Control at FHI. We have asked you to answer why many people may be infected with the coronavirus, but without developing symptoms of the disease.

Among those examined, the most common infection is now in the 20-39 age group.

But many young people have weak or even no symptoms. The latter is called asymptomatic disease.

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1. What exactly is an asymptomatic disease?

We distinguish between two categories: In one, the entire disease progresses without symptoms or without the infected person feeling ill. In the second, the person has no symptoms in the first part of the course of the disease and has symptoms later. When we talk about infection by asymptomatic people, it applies to both categories.

2. How common is it?

For covid-19, we don’t yet know how common it is or if there are differences between age groups. It may appear that between 20 and 40 percent of cases are asymptomatic.

Isn’t it strange that I’m sick without feeling sick?

It can vary from person to person. In some people, the infection may be so mild that it does not feel sick. Others may have some symptoms that they also struggle with as usual. These symptoms can mask the symptoms of Covid-19.

In infectious diseases, it is not known how many people carry the disease without symptoms. To find out more about how many people have an asymptomatic infection, many of them should be examined. healthy population.

4. What is particularly difficult?

A basic measure to reduce infection is for all patients with symptoms to stay home. But before one develops symptoms, it is not possible. Much of the work with infection tracking and quarantine is aimed at this goal. People who have been exposed to the infection and are defined as close contact should be quarantined.

As infection in the community increases, the likelihood of meeting people with asymptomatic disease increases. Therefore, it is important to keep your distance, even from people without known illnesses. Distance is the most important measure to limit infection.

5. Are people without symptoms less contagious than others when they cough?

We estimate that a person is most contagious in the early part of the disease course. Then the amount of virus in the body increases rapidly and symptoms appear. One can be contagious just before symptoms appear. People with a completely asymptomatic course of the disease are likely to be less contagious. Or they can be contagious for a short period of time. But we still do not have a certain knowledge of this.

6. What happens in the body in case of asymptomatic infection?

When infected, the virus enters cells in the respiratory tract. This is where the multiplication of the virus begins. The body responds, among other things, with an inflammatory reaction. Several common symptoms of infectious diseases are due to such a reaction. When the infection is asymptomatic, we expect the inflammatory response to be milder.

7. How do you know if you have an asymptomatic infection?

Tests that detect infection will also detect infection in people without symptoms of Covid-19. People who do not have symptoms are tested in the same way. The way to detect the infection is the same.

8. How important is it to find these people?

Anyone who suspects they are infected should get tested. You don’t need to have symptoms. We also want to find infection in those who do not have the typical symptoms of the disease. It is useful for quickly advancing infection detection work and finding close contacts. Then further spread is prevented.

9. Do the tests tell where you are in the course of the disease?

The tests that are used are called PCR (“polymerase chain reaction test”). CRP does not differentiate between how active the disease is in the body. PCR can be positive, even if you only have residues of the virus in your body and you are no longer contagious. But it is possible to grow the virus sample. Then you will find out if there is virus residue or an active virus. The method is only used in very special cases.