Prevent the Spread of Norovirus

Noroviruses are a group of related viruses. Infection with these viruses affects the stomach and intestines and causes an illness called gastroenteritis (GAS-tro-en-ter-I-tis; inflammation of the stomach and intestines).

Anyone Can Get Norovirus

Anyone can be infected with noroviruses and get sick. Also, you can get norovirus illness more than once during your life. The illness often begins suddenly. You may feel very sick, with stomach cramping, throwing up, or diarrhea.
Noroviruses are the most common cause of gastroenteritis in the United States. CDC estimates that each year more than 20 million cases of acute gastroenteritis are caused by noroviruses. That means about 1 in every 15 Americans will get norovirus illness each year. Norovirus is also estimated to cause over 70,000 hospitalizations and 800 deaths each year in the United States.

Many Names, Same Symptoms

Norovirus Outbreaks

Oysters linked to norovirus outbreak in Washington State

FDA is warning consumers to not eat certain ASSI Brand frozen oysters following a norovirus outbreak in Washington State in October 2011
Norovirus outbreak strikes NBA in 2010

Overall, 21 players and three staff from 13 National Basketball Association (NBA) teams in 11 states were affected by a norovirus outbreak from November to December 2010
Impact of new norovirus strain on outbreaks

Norovirus caused the majority of acute gastroenteritis outbreaks in the United States from 2007 to 2010. However, a new strain that emerged in 2009 did not lead to more outbreaks.

You may hear norovirus illness called "food poisoning" or "stomach flu." It is true that food poisoning can be caused by noroviruses. But, other germs and chemicals can also cause food poisoning. Norovirus illness is not related to the flu (influenza), which is a respiratory illness caused by influenza virus.

Symptoms of norovirus infection usually include diarrhea, throwing up, nausea, and stomach cramping.
Other, less common symptoms may include low-grade fever, chills, headache, muscle aches, and general sense of fatigue.

Norovirus illness is usually not serious. Most people get better in 1 to 2 days. But, norovirus illness can be serious in young children, the elderly, and people with other health conditions; it can lead to severe dehydration, hospitalization and even death.

You may get dehydrated if you are not able to drink enough liquids to replace the fluids lost from throwing up or having diarrhea many times a day. Symptoms of dehydration include a decrease in urination, a dry mouth and throat, and feeling dizzy when standing up. Children who are dehydrated may also cry with few or no tears and be unusually sleepy or fussy.

The best way to prevent dehydration is to drink plenty of liquids. Oral rehydration fluids are the most helpful for severe dehydration. But other drinks without caffeine or alcohol can help with mild dehydration. However, these drinks may not replace important nutrients and minerals that are lost due to vomiting and diarrhea.

If you think you or someone you are caring for is severely dehydrated, contact your doctor. For more information on norovirus and dehydration, see How is viral gastroenteritis treated?

Norovirus Spreads Quickly

Norovirus can spread quickly from person to person in crowded, closed places like long-term care facilities, daycare centers, schools, hotels, and cruise ships. Noroviruses can also be a major cause of gastroenteritis in restaurants and catered-meal settings if contaminated food is served.

Norovirus and Food

Norovirus is a leading cause of disease from contaminated foods in the United States. Foods that are most commonly involved in foodborne norovirus outbreaks include leafy greens (such as lettuce), fresh fruits, and shellfish (such as oysters). However, any food item that is served raw or handled after being cooked can become contaminated with noroviruses.

The viruses are found in the vomit and stool of infected people. You can get it by

Eating food or drinking liquids that are contaminated with norovirus (someone gets stool or vomit on their hands, then touches food or drink).
Touching surfaces or objects contaminated with norovirus and then putting your hand or fingers in your mouth.
Having direct contact with a person who is infected with norovirus (for example, when caring for someone with norovirus or sharing foods or eating utensils with them).

People with norovirus illness are contagious from the moment they begin feeling sick until at least 3 days after they recover. But, some people may be contagious for even longer.

Norovirus: No Vaccine and No Treatment

There is no vaccine to prevent norovirus infection. Also, there is no drug to treat people who get sick from the virus. Antibiotics will not help if you have norovirus illness. This is because antibiotics fight against bacteria, not viruses. The best way to reduce your chance of getting norovirus is by following some simple tips.

Stop the Spread of Norovirus

Practice proper hand hygiene

Wash your hands carefully with soap and water, especially after using the toilet and changing diapers and always before eating or preparing food. If soap and water aren't available, use an alcohol-based hand sanitizer. These alcohol-based products can quickly reduce the number of germs on hands in some situations, but they are not a substitute for washing with soap and water.

Take care in the kitchen

Carefully wash fruits and vegetables, and cook oysters and other shellfish thoroughly before eating them.

Do not prepare food while infected

People with norovirus illness should not prepare food for others while they have symptoms and for 3 days after they recover from their illness (see Norovirus: Food Handlers).

Clean and disinfect contaminated surfaces

After throwing up or having diarrhea, immediately clean and disinfect contaminated surfaces by using a bleach-based household cleaner as directed on the product label. If no such cleaning product is available, you can use a solution made with 5 tablespoons to 1.5 cups of household bleach per 1 gallon of water.

Wash laundry thoroughly

Immediately remove and wash clothing or linens that may be contaminated with vomit or stool. Handle soiled items carefully—without agitating them—to avoid spreading virus. If available, wear rubber or disposable gloves while handling soiled clothing or linens and wash your hands after handling. The items should be washed with detergent at the maximum available cycle length and then machine dried.