Noroviruses (Norwalk) are a family of viruses that commonly cause diarrheal illnesses or gastroenteritis in people. The illness often begins suddenly, 24 to 48 hours after exposure to the virus. The symptoms include:

• nausea
• vomiting
• diarrhea
• stomach cramps

In most healthy people, the symptoms typically last eight to 12 hours, with complete recovery after 48 hours. Symptoms may last longer in some people. Drink plenty of fluids to prevent dehydration. Contact your doctor if symptoms are severe or if you are concerned.

Norovirus is present in the stool and vomit of infected people. It is easily transmitted by contact with contaminated surfaces and objects.

The best protection is frequent hand washing. Use soap and warm water. If you cannot wash with soap and warm water, use an alcohol-based hand rub with an alcohol content of at least 70%.

• If you are sick, stay at home.
• Keep ill children home and minimize contact with family members to stop the illness from spreading.
• Pay extra attention to cleaning surfaces and utensils that the ill person has been in contact with.

The public's response to the presence of a gastrointestinal infection in the community plays a significant role in limiting the severity of the outbreak. If a health facility has an outbreak of norovirus, visitor restrictions will likely be posted at facility entrances. Admissions, transfers and discharges from the facility may be discontinued until the outbreak is over.