Norovirus is a very contagious virus that causes vomiting and diarrhea. People of all ages can get infected and sick with norovirus.
People with norovirus illness can shed billions of norovirus particles. And only a few virus particles can make other people sick.
- Having direct contact with an infected person
- Consuming contaminated food or water
- Touching contaminated surfaces and then putting your unwashed hands in your mouth
You can get norovirus illness many times in your life because there are many different types of noroviruses. Infection with one type of norovirus may not protect you against other types. It is possible to develop immunity to (protection against) specific types. But, it is not known exactly how long immunity lasts. This may explain why so many people of all ages get infected during norovirus outbreaks. Also, whether you are susceptible to norovirus infection is also determined in part by your genes.
Learn more about symptoms of norovirus illness and dehydration.
Learn how norovirus spreads from person to person and through contaminated food, water, and surfaces.
Learn steps you can take to help protect yourself and others from getting infected with and sick from norovirus.
Learn how to relieve symptoms if you get norovirus illness.
Norovirus is sometimes called the stomach flu or stomach bug. However, norovirus illness is not related to the flu which is caused by influenza virus.