Norovirus is the name of a group of viruses that is a common cause of viral gastroenteritis ("stomach flu") outbreaks. Norovirus is not related to flu or influenza. Although people who have norovirus infection may feel very sick for several days, the illness is seldom serious. Norovirus outbreaks are common during the winter months, when people are indoors and in close contact.


Symptoms often begin suddenly within 12 to 48 hours after exposure to norovirus. Most people get better within one or two days and have no long-term health effects from the illness, though dehydration (loss of fluids) may ocur and may result in hospitalization.

Symptoms include:


Norovirus is found in the stool and vomit of infected people. It is very contagious and usually spread person-to-person, or by contaminated food. People can become infected with the virus by:

Norovirus can spread quickly in places with close living quarters, such as childcare centers, long-term care facilities, and cruise ships. People who work in these types of facilities should carefully follow steps to prevent the spread of infection when caring for children or residents who may have a norovirus infection. People infected with norovirus are contagious from the moment they begin feeling ill to, at least, three (3) days after symptoms end.


You can decrease your chance of becoming ill with norovirus, or of spreading norovirus to others by following these recommendations:


Norovirus outbreaks (not individual cases) are reportable to Public Health. Health care and long term care facilities should report suspected or confirmed norovirus outbreaks to Public Health by calling 538-2840 in Oroville or 891-2732 in Chico.


CDPH Norovirus (Norwalk Virus)

CDC Respiratory and Enteric Viruses Branch - Norovirus


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