Norovirus is a very common, and potentially serious, stomach “bug” or “stomach flu.” By taking steps to prevent it, you and your family can avoid the diarrhea, vomiting and stomach pain it causes for more than 20 million people every year. Norovirus can be especially dangerous for young children and older adults.

Norovirus is responsible for at least half of all severe stomach upset with diarrhea and vomiting. Also called food poisoning, norovirus is the leading cause of foodborne disease outbreaks in the United States. Norovirus is not related to influenza, although it’s often called “stomach flu.”

Although most people get better in one to three days, norovirus can quickly develop into a serious illness. It causes about 70,000 hospitalizations and more than 800 deaths every year. Most of the deaths are in young children and elderly people.

Norovirus spreads quickly, especially in areas like daycare centers, nursing homes, schools, cruise ships, and institutions such as prisons, hospitals or military encampments. It spreads through contact with a sick person who has it, eating food/beverages that have norovirus germs, or touching surfaces or things that have norovirus germs and then putting fingers in your mouth.

Although more common in the winter months, you can get norovirus any time of year. About a quarter of all cases are caused by food or water contamination. The rest of the cases are person-to-person contact or touching contaminated surfaces.


Symptoms usually develop within 12 to 48 hours after being exposed to norovirus. The norovirus infection causes inflammation of the stomach and intestines. This leads to diarrhea, vomiting and stomach pain or cramping. In addition to the stomach symptoms, fever, headache and body aches are also common.

Norovirus can quickly lead to dehydration and more serious illness. The symptoms of dehydration are dry mouth and throat, decrease in peeing, or feeling dizzy when standing up. Children who are dehydrated may cry with few or no tears, and be unusually sleepy or fussy.


Drink plenty of liquids to replace fluids that have been lost from throwing up and diarrhea. Sports drinks and other fluids without caffeine or alcohol can help with mild dehydration. But, these drinks may not replace important nutrients and minerals. Oral rehydration fluids that you can get over-the-counter are most helpful for dehydration.

In cases of severe dehydration, get the person to a doctor or hospital quickly. Intravenous (IV) fluids may have to be given to prevent complications and even save a life.

There is no vaccine to prevent norovirus, nor any medicine to specifically treat it. Because it is a virus, antibiotics have no effect on it. You can get it more than once and most people have it several times during their life.

Prevention tips

  1. 1. Wash hands frequently and carefully – for at least 20 seconds – with soap and running water, every time you:
  • Use the toilet
  • Change diapers
  • Before you eat or drink
  • Before handling or preparing food
  • After caring for a sick person

If soap and water are not available, use an alcohol-based hand sanitizer as a substitute. However, soap and water are far more effective against norovirus than hand sanitizer. Washing your hands frequently is the single-most important way to prevent the illness and prevent others from getting it.

  1. Do not prepare food or care for other people while you are sick, and for at least two days after your symptoms stop. The virus can still be in your body for weeks after you recover.
  2. 3. Isolate sick people from the rest of the family in a separate room, if possible. Limit their contact with healthy people. Never let sick people share food, silverware, or dishes with healthy people. Keep sick children away from where food is being handled and cooked. Stay home from work or school for at least two days after the end of symptoms. This can help protect others as well as prevent surface contamination. It is especially important to do this in areas where people live or work in close contact with each other.
  3. Disinfect contaminated surfaces (hard and nonporous) with a disinfectant that the Environmental Protection Agency (EPA) has registered as effective against norovirus. You can also use a chlorine bleach solution. Prepare it by adding 5 to 25 tablespoons of bleach to a gallon of clean water and mix. Use this within 24 hours to insure its effectiveness. It’s especially important to disinfect surfaces in bathrooms, kitchens and the sick person’s room. Be sure to disinfect high-touch areas such as door and appliance knobs, light switches and hand rails. Norovirus can stay on objects and surfaces and still infect people for weeks.
  4. Carefully wash fruits, vegetables and shellfish before eating or cooking. Thoroughly cook oysters and other seafood. Norovirus can survive temperatures as high as 140 degrees. It can also survive the quick steaming process that is often used to cook seafood and shellfish. The foods most commonly involved in norovirus outbreaks are leafy greens, lettuce, fresh fruits and shellfish.
  5. Food service workers should avoid cooking, handling or serving food and beverages while sick, and for up to two days after symptoms end. Always wear disposable gloves when handling or preparing food.
  6. Wash clothes, linens and towels immediately if they have been contaminated or may have been contaminated by touching the sick person. Handle soiled clothes carefully without agitating them. Wear disposable gloves while handling soiled items. Wash your hands after the clothes are in the washing machine. Use the longest available wash-cycle length and machine dry them.
  7. Be extra careful about cleanliness during and after exposure to norovirus. Norovirus can stay in your body for up to two weeks after symptoms end.