You are here : Diseases & Risks  >  Norovirus


Norovirus is a very contagious virus sometimes mistakenly called stomach flu. It is also one possible cause of "food poisoning."

You can get norovirus from an infected person, contaminated food or water, or by touching contaminated surfaces. The virus causes stomach pain, nausea, diarrhea and vomiting because your stomach or intestines or both to get inflamed (acute gastroenteritis).

Norovirus spreads easily and rapidly — especially in schools, child care settings, and assisted living facilities

The Snohomish Health District follows up on cases of gastrointestinal illnesses like norovirus when they might be part of a larger outbreak. If you think you got sick after eating in a restaurant or from well water or another water supply, please contact us. We also send out letters to notify parents in the case of outbreaks in schools and child care settings.

Norovirus symptoms

  • A sudden onset of illness, usually 24–48 hours after exposure

  • Vomiting and nausea 

  • Diarrhea and stomach cramps 

  • Headaches, chills, a low-grade fever, muscle aches, and tirednes

  • Symptoms lasting for 1 to 2 days    

The virus can be serious, especially for young children or older adults.

Preventing the spread of norovirus

There are no specific drugs or vaccines to treat or prevent norovirus. Taking the following precautions will help prevent the spread of the infection:

  • Wash hands after using the bathroom

  • Don't prepare food for others while sick - you can easily spread the virus

  • Keep children with symptoms home from school or child care and notify your child care provider of the illness

  • Take care in the kitchen, including washing fruits and vegetables thoroughly 

  • Clean and disinfect contaminated surfaces with a solution of bleach and water

  • Wash all clothes and linens soiled by vomit or fecal matter immediately

Contact us

Communicable Disease Surveillance & Response


Did you know?

Norovirus is the most common cause of acute gastroenteritis in the United Sates, causing 19–21 million illnesses, including up to 800 deaths, each year.