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Norovirus, previously called Norwalk virus, is a very contagious virus that spreads quickly and causes vomiting and diarrhea.  Norovirus is one of the most common causes of viral gastroenteritis (inflammation of the stomach and intestines) which is also sometimes called the “stomach flu” or “stomach bug” but is NOT related to the flu which is caused by influenza viruses.  Norovirus causes over half of foodborne illnesses and outbreaks such as on cruises or in nursing homes, schools or daycares.

Norovirus infections are NOT reportable in Orange County, unless associated with an outbreak (which should be reported immediately by phone (714-834-8180) to OCHCA Epidemiology).  Information and resources for schools and child cares with norovirus are available on the OCHCA Epidemiology School webpage

Frequently Asked Questions

Health Care Professionals

For more information, see the Centers for Disease Control (CDC) website

Last reviewed December 18, 2018