Norovirus is a very contagious gastrointestinal illness that can affect anyone. You can get the virus from an infected person, contaminated food or water, or by touching contaminated surfaces. The virus causes your stomach or intestines or both to get inflamed. This leads to stomach pain, nausea, diarrhea and vomiting.

Anyone can become infected with norovirus and get sick, even if they've had it before. Norovirus can be very serious, especially for young children and older adults.

Norovirus is the most common cause of acute gastroenteritis in the United States. Each year, it causes 19-21 million illnesses and contributes to 56,000-71,000 hospitalizations and 570-800 deaths. Norovirus is also the most common cause of foodborne-disease outbreaks in the United States.

You may hear norovirus illness called "food poisoning" or "stomach flu." Food poisoning can be caused by noroviruses; however, other germs, toxins, and chemicals can also cause food poisoning. Norovirus illness is not related to the flu (influenza), which is a respiratory illness caused by influenza virus.

What are the symptoms of norovirus?

Norovirus causes inflammation of the stomach or intestines or both, which is called acute gastroenteritis. The most common symptoms include diarrhea, vomiting, nausea, and abdominal pain. Other symptoms can include fever, headache, and body aches. Symptoms of norovirus can lead to dehydration. Symptoms of dehydration include decreased urination, dry mouth and throat, and feeling dizzy when standing up. Children who are dehydrated may cry with few or no tears, and be unusually sleepy or fussy.

Most people with norovirus illness get better within 1 to 3 days.

How is norovirus spread?

Norovirus is transmitted through contact with vomit or feces of infected individuals. The virus is usually spread by:

• eating food or drinking liquids that are contaminated with norovirus,
• touching surfaces or objects contaminated with norovirus then putting your fingers in your mouth, or
• having contact with someone who is infected with norovirus (e.g., caring for or sharing food or eating utensils with someone with norovirus).

Norovirus can spread quickly in places like childcare centers, nursing homes, schools, and cruise ships. Most norovirus outbreaks happen from November to April in the United States.

What is the treatment for norovirus?

There is no specific drug to treat people with norovirus illness. There also is no vaccine to prevent norovirus infection. Norovirus cannot be treated with antibiotics because it is caused by a virus, not a bacteria.

People with norovirus should drink plenty of liquids to help prevent dehydration. Dehydration can lead to serious problems, so it is important to contact a healthcare provider if you think you or someone you are caring for is severely dehydrated.

How can the spread of norovirus be prevented?

      Wash your hands carefully with soap and water, especially after using the toilet or changing diapers. Always wash your hands before eating, preparing or handling food.

      Wash fruits and vegetables before eating them.

      Cook seafood thoroughly. Norovirus outbreaks can be caused by seafoods, such as oysters, that were contaminated at their source.

      When you are sick, do not prepare food for others. The North Dakota Department of Health requires that food handlers with norovirus illness must be excluded from work for at least 48 hours after their symptoms stop.

      Do not provide care for others while you are sick and for at least two days after your symptoms stop. This also applies to sick employees in settings such as schools and daycares. 

      Clean and disinfected contaminated surfaces. After throwing up or having diarrhea, immediately clean and disinfect contamianted surfaces. Use a chlorine bleach solution with a concentration of 1000-5000 ppm (5-25 tablespoons of household bleach [5.25%] per gallon of water) or other disinfectant registered as effective against norovirus by the Environmental Protection Agency (EPA).

   Wash laundry thoroughly. Immediately remove and wash clothes or linens that may be contaminated with vomit or stool. You should:

• handle soiled items carefully without agitating them,
• wear rubber or disposable gloves while handling soiled items and wash your hands after, and
• wash the items with detergent at the maximum available cycle length then machine dry them.

For additional information on norovirus:

     Online Gastrointestinal (GI) Outbreak Reporting Form for Institutions

      Norovirus Fact Sheet (PDF)

      Norovirus in Healthcare Facilities (PDF)

      Key Infection Control Recommendations for the Control of Norovirus Outbreaks in Healthcare Settings (PDF)

      Norovirus Toolkit for Healthcare Settings (CDC website)

      Guidelines for the Prevention and Control of Norovirus Gastroenteritis Outbreaks in Healthcare Settings, 2011 (CDC website) 

      Updated Norovirus Outbreak Management and Disease Prevention Guidelines (CDC MMWR, March 4, 2011 / 60(RR03);1-15)

      EPA's Registered Antimicrobial Products Effective Against Norovirus (EPA website)