The Centers for Disease Control and Prevention (CDC) says norovirus is the most common cause of acute gastroenteritis in the U.S.  Each year, norovirus causes 19 to 21 million cases of acute gastroenteritis in the U.S.


On Friday, two school districts reported the effects of the rapidly contagious gastrointestinal virus see hundreds of kids infected and out of school.

In Greeley, CO, health officials in Weld County reported that some 166 Shawsheen Elementary school students were out on Friday due to norovirus infection.

In an update from Reno, NV, Washoe County officials say 17 schools and 3 daycare facilities have been affected by norovirus encompassing some 776 ill students as of Friday. Two schools have been taken off the outbreak list, leaving the number active at 15.

Norovirus spreads by contact with an infected person, by touching a contaminated surface, or eating contaminated food or water. The most common symptoms are diarrhea, vomiting, nausea, and stomach pain. Other symptoms include fever, headache, and body aches. The incubation period for norovirus can be anywhere from 12-48 hours after exposure.

There are no medications to prevent or cure norovirus. One of the most common complications from norovirus is dehydration. It is important to stay hydrated by drinking water or sports drinks. If an individual becomes too dehydrated, seek medical help.

With colder weather coming, people will be inside and in close company. To prevent the spread of norovirus, the Weld County Health Department recommends the following:

• Practice proper hand hygiene. Wash your hands carefully with warm soapy water, especially after using the toilet and changing diapers. Always wash hands before eating and preparing or handling food. “It’s important to realize many disinfectant products, including hand sanitizers, are not effective at killing norovirus,” said Mark Wallace, MD, Executive Director of the Health Department. “Washing frequently with warm soapy water works best.”

• Do not prepare food or care for others if you are sick. You should not prepare food for others or provide care while you are sick and for at least 2 to 3 days after you recover. This also applies to sick workers in settings such as schools, restaurants, and daycare centers where they may expose people to norovirus. Students should also not return to school until at least 48 hours after they begin to feel well.

• Clean and disinfect contaminated surfaces. After vomiting or having diarrhea, immediately clean and disinfect contaminated surfaces. Use a chlorine bleach solution of 1/3 cup chlorine per 1 gallon of water.

• Wash laundry thoroughly. Immediately remove and wash clothes or linens that may be contaminated with vomit or feces. Wear rubber or disposable gloves while handling soiled items and wash items with detergent at the maximum available cycle length and at the highest temperature, including machine drying at the highest temperature.