Norovirus Infection



A group of viruses cause this infection. They can spread through:

  • Water that is not clean, such as lakes, swimming pools, wells, and water stored on cruise ships
  • Raw or poorly steamed shellfish, such as clams and oysters
  • Food and drinks made by people who have the infection and do not wash their hands well after using the bathroom
  • Surfaces, such as a door knob

The viruses can also spread by being around someone who is sick.

Risk Factors

Any person who ingests the virus is at risk of getting this infection. It is more common in young children and older adults.

This infection is common in crowded settings such as:

  • Cruise ships
  • Restaurants
  • Nursing homes
  • Hospitals
  • Child care centers
  • Hotels



A person with a norovirus infection may have:

  • Nausea
  • Vomiting
  • Diarrhea
  • Belly pain
  • Fever

These symptoms often appear within 24 to 48 hours of getting the virus. They often last about two to three days.


The doctor will ask about symptoms and health history. A physical exam will be done. This is often enough to make the diagnosis.

Stool tests may be done if the doctor wants to find out which virus is causing the infection.



Infections caused by a virus cannot be treated with antibiotics. The infection will go away on its own. Symptoms can be managed with:

  • Supportive care, such as drinking plenty of fluids
  • Medicines to ease pain, such as acetaminophen


To lower the risk of this problem:

  • Practice proper hand washing.
  • Handle and prepare food safely.
  • Avoid people who are sick.
  • Clean and disinfect surfaces.

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.

Edits to original content made by Denver Health.