Transmission and course of the disease

Washing hands

Illustration: Johnér

Transmission and incubation time

The coronavirus spreads by droplet transmission, via direct contact and indirect contact. The virus is found in small droplets in the mouth and nose of an infected person and becomes airborne through sneezing or coughing, talking or singing.

The typical route of transmission occurs when you inhale the airborne virus or when your hands come into contact with the virus and you then touch your face. The virus is transferred by direct contact for example when a healthy person shakes hands with an infected person. The virus is transferred by indirect contact for example when an infected person with virus on their hands touches a door handle that is later touched by a healthy person.

Transmission occurs just when you turn ill and at the beginning of the course of the disease. There are clear indications that the risk of transmission is relatively high one to two days before the onset of symptoms. Contact tracing is therefore performed from 48 hours prior to the onset of symptoms.

Can the virus be transmitted by people who do not display any symptoms?

While the most typical route of transmission is via a person who displays symptoms, infection can also occur just prior to symptoms developing.

Incubation time

Very few people turn ill more than 8–9 days after being exposed to the virus. Quarantine time is therefore set at 10 days.

What should I do if I suspect that I am infected?

  • If you feel unwell, you should stay at home.
  • Read about the symptoms of coronavirus and testing.
  • If you are ill and in need of medical attention or individual health counselling, contact your doctor electronically or by telephone.
  • If you need urgent health assistance and cannot reach your doctor, you can call the emergency out-of-hours clinic (116 117).
  • In case of life-threatening illness or injury, call 113.

How to prevent transmission

Here's what you can do to prevent transmission:

  • Keep a distance of at least one metre to others.
  • Cough into a paper tissue or the crook of your elbow.
  • Wash hands frequently and thoroughly with soap and luke-warm water, or use an alcohol-based disinfectant.
  • Find alternatives to shaking hands and hugging.

Face masks

A face mask is recommended to help reduce the risk of transmission in situations where the level of infection is high. A face mask cannot replace the standard measures for infection control such as social distancing.

Read more about face masks.

Cleaning of surfaces and items

It is not known precisely for how long the virus can survive on surfaces. This will vary depending on the surface, temperature, sunlight and humidity. As the virus can be found on surfaces, washing of hands is the key preventive measure.

The Norwegian Directorate of Health has encouraged providers of public transport to perform extra cleaning of subway cars, buses, trams etc.

The Norwegian Directorate of Health is also encouraging extra cleaning of areas where many people frequent.

You may want to regularly clean items that are frequently touched, such as your mobile phone or the keyboard of your computer.

Limit the number of close contacts

It is recommended that we all limit our number of close contacts to allow for easier contact tracing by the municipalities.
If you are about to attend a social gathering or an event it is important that you stay up-to-date on the advice and rules that apply.

Course of the disease

The course of the disease can vary widely between individuals. Currently, the typical courses appear to be:

  • Mild course (this applies to the majority of those who turn ill, about eight out of ten): The symptoms pass within one to two weeks and there is rarely a need for treatment in the healthcare services.
  • Moderate course: After four to seven days with only mild symptoms, some people may experience breathing difficulties, worsening cough and a rising fever. If you experience breathing difficulties, you should contact your doctor. Some will need to be admitted to hospital.
  • Severe course: Similar to what is seen with the moderate course, but with a need for intensive care treatment. The patients may have symptoms for three to six weeks. Deaths do occur for some of those who turn seriously ill.

Information and knowledge about risk factors for a severe progression of COVID-19 is constantly growing. Admission to hospital, intensive care treatment and deaths are more common among the elderly and people with underlying diseases. The risk is increased with age and underlying diseases in particular. Younger persons without any known risk factors, can also experience a severe illness, but the risk is higher with underlying disease.

Treatment of coronavirus disease

There is no vaccine or specific treatment to cure the disease, but hospitals in Norway are registering patients with confirmed coronavirus infection in the Norwegian pandemic register (Norsk pandemiregister) to allow for improvements in treatment and follow-up.

See more information about the Norwegian pandemic register.