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Norovirus Infection

Norovirus Infection Quick Overview

  • Norovirus is a virus that causes nausea, vomiting, and diarrhea, known as acute gastroenteritis or "stomach flu."
  • Norovirus is the most common cause of food-borne disease outbreaks in the U.S.
  • Norovirus is highly contagious and often occurs in outbreaks where people are in close contact, such as dorms, cruise ships, or nursing homes.
  • Symptoms of norovirus typically last for one to three days.
  • Norovirus infection typically resolves on its own with an excellent prognosis. The elderly, people with suppressed immune systems, and those with chronic health conditions may develop complications.
  • There is no vaccine currently available to prevent norovirus infection.
  • Because there are multiple strains of the virus and the fact that the body does not produce a strong immune response to the infection, experts believe it is possible to contract norovirus infection more than once in a lifetime.
  • No specific treatment is generally required for norovirus, but it is important to maintain good hydration.
  • Hand washing and good hygienic practices are key to preventing the spread of norovirus infection. Proper cooking and handling of food supplies can prevent outbreaks.

What Is Norovirus?

Norovirus is a common viral infection that causes a person to develop a rapid onset of nausea, vomiting, diarrhea, and occasionally stomach cramping (all symptoms of gastroenteritis). In addition, the person may feel tired, have muscle aches, a headache, and a low-grade fever (less than 101 F) with chills. The symptoms last about one to two days. Although no long-term problems persist or develop with this viral infection, dehydration (loss of body water) may be significant enough to require medical treatment.

Norovirus was probably first noticed by Dr. J. Zahorsky in 1929 and termed "winter vomiting disease." In 1968 in Norwalk, Ohio, there was an outbreak of gastroenteritis thought to be caused by a virus. The virus was termed the Norwalk agent (also termed particle or virus). It was classified as a "small round virus" and later, after genetic studies, classified as a member of the family Caliciviridae, with a single strand of RNA for its genome. The name of the genus, Norovirus, was approved in 2002 by an international committee.

Researchers suggest norovirus is responsible for about 50% of all outbreaks of gastroenteritis in the U.S. and about 90% of epidemic nonbacterial gastroenteritis outbreaks worldwide. It is the most common cause of outbreaks of food-borne illness in the U.S. Most outbreaks or epidemics occur in places where people come together in close contact (for example, dorms, hospitals, prisons, cruise ships, schools, and nursing homes). Norovirus infections are transmitted from person to person, by contaminated food and water, and by contact with norovirus-contaminated surfaces. One recent outbreak of norovirus occurred in Yellowstone National Park during the summer of 2013. A touring group apparently brought the virus into the area and over 200 individuals came down with the disease.

Medically Reviewed by a Doctor on 11/17/2017

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How are infections with noroviruses treated?

You treat gastroenteritis caused by noroviruses by managing complications until it passes. Dehydrationcaused by diarrhea and vomiting is the most common complication. Do not use medicines, including antibioticsand other treatments, unless your doctor recommends them.

To prevent dehydration, take frequent sips of a rehydration drink (such as Pedialyte). Try to drink a cup of water or rehydration drink for each large, loose stool you have. Soda and fruit juices have too much sugar and not enough of the important electrolytesthat are lost during diarrhea, and they should not be used to rehydrate. In cases of severe dehydration, fluids may need to be replaced through an IV (intravenously).


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