What is norovirus?

Norovirus is the term for a group of viruses that causes severe vomiting and diarrhea. It is very common and very easy to spread (contagious). It can spread through infected people, contaminated food, or contaminated surfaces. While many people call norovirus “the stomach flu,” it has no relation to the flu (influenza).

What causes norovirus?

People can become infected with norovirus in many ways. You can get the virus through close contact with someone who is sick, by touching contaminated surfaces and then touching your mouth, or by eating or drinking contaminated foods or water.

Norovirus is the biggest cause of illness from contaminated food in the U.S. The virus typically spreads when an infected food worker touches food before serving it. Sometimes certain foods, including oysters and other seafood, are naturally contaminated with norovirus.

What are the symptoms of norovirus?

Norovirus can make you feel very sick. Symptoms usually appear 12 to 48 hours after your exposure to the virus and last 2 or 3 days. These symptoms can appear suddenly and include:

Last reviewed by a Cleveland Clinic medical professional on 01/25/2018.


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