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This fact sheet answers frequently asked questions about norovirus.

Noroviruses are a group of viruses that cause diarrhea, vomiting and stomach pain. Norovirus is often called by other names such as viral gastroenteritis, stomach flu, and food poisoning. It is not related to the flu (influenza), which usually causes respiratory illness.

The basics

Who gets norovirus?

Anyone can develop this disease. You can find norovirus worldwide, it occurs only in humans. It is very common and spreads easily.

How does it spread?

You can find noroviruses in the stool or vomit of infected people. Noroviruses transfer to food, water, or surfaces when people touch food after using the bathroom and not washing their hands.

People become infected with norovirus by:

  • Eating food or drinking liquids contaminated by an infected person
  • Eating uncooked shellfish harvested from contaminated waters
  • Touching contaminated surfaces or objects and then touching your mouth or eating without washing your hands first


What are the symptoms?

Symptoms usually begin 1 to 2 days after exposure to the virus, but can occur as early as 12 hours after exposure. Common symptoms include nausea, diarrhea, vomiting, and stomach pain. Sometimes people may develop low-grade fever, chills, headache, muscle aches, and tiredness. The illness may come on suddenly, and it is possible to have norovirus infection many times. Sometimes people with norovirus have no symptoms at all, but can still pass the infection on to others.

How long does it last?

Most people recover in 1 to 2 days. Sometimes infected people lose fluids quickly and can become dehydrated. This is more likely to occur in very young children, the elderly or those with certain other health problems.

What should I do if I have these symptoms?

Drink plenty of fluids to avoid dehydration. Wash your hands often and contact your healthcare provider if you have any concerns.


How can I prevent norovirus infection?

  • Wash your hands often with soap and warm water, especially:
    • After using the bathroom
    • After changing diapers
    • Before preparing foods
    • Before eating
  • Be sure to wash your hands more often when someone in your household is sick
  • Clean and disinfect surfaces immediately after vomiting or diarrheal accidents
  • Cook food appropriately (especially shellfish)
  • Wash and/or peel fruits and vegetables before eating them
  • Avoid preparing food for others while you have symptoms and for at least 3 days after you recover

Should I stay home from work or school?

Yes. To prevent spreading the illness to others, a sick person should stay home until they have completely recovered. Under public health regulations, food handlers and healthcare workers must stay out of work for 72 hours after their symptoms have resolved.

Click here for norovirus information from the Centers for Disease Control and Prevention.

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