Overview of Norovirus or the Cruise Ship Virus

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Norovirus is the number one cause of gastroenteritis, or stomach flu, in the United States. It is a highly contagious virus that causes inflammation in the stomach and intestines. It is also the most common cause of "food poisoning" in the US because it can easily contaminate and spread via food.

Norovirus is also known as Norwalk virus, or "the cruise ship virus," because of the multiple outbreaks that have occurred on cruise ships.

Girl holding her stomach while laying in bed
Renaud Philippe / EyeEm / Getty Images


Symptoms of norovirus are the same as symptoms of other types of stomach flu:

  • Vomiting
  • Diarrhea
  • Cramping/Stomach Pain
  • Nausea
  • Fever
  • Headache
  • Body Aches

When Are You Contagious?

Norovirus can be contagious before you start showing symptoms, and for as long as two weeks after you start to feel better. But it's most contagious while you're sick, and during the first three days after your symptoms subside.

Risk Factors

Norovirus sickens 19 to 21 million people a year and leads to approximately 570 to 800 deaths. Those at highest risk are young children and older adults. Both of these groups have immune systems that aren't as strong as those of older children or adults who are otherwise healthy, making it more difficult to recover from the symptoms, and leading to complications.

Possible Complications

The most common complication of a stomach virus is dehydration. If not treated, dehydration can be very serious. If you are unable to keep even small amounts of fluid down or have had very severe diarrhea (or both), you may be dehydrated. Severe dehydration may require medical treatment such as IV fluids or medications to help stop the vomiting. If you think you might be dehydrated due to vomiting or diarrhea, contact your healthcare provider.


Most people who get norovirus will not need any medical treatment. Typically, it's something that can be treated at home and will go away on its own.

If you are concerned about vomiting or you aren't sure what to do to treat it at home, this guide will take you through every step you need to take when you are vomiting.

Occasionally, a norovirus infection will be bad enough to require medical treatment. Although there is no medication that can kill or cure the infection, there are medications that can help stop or reduce vomiting so that you don't get dehydrated—or you can rehydrate if your body is already dehydrated. These medications are available only by prescription, so it's important to seek medical attention if you think it's something you need.


Because norovirus is so contagious, it can be hard to avoid. There is no vaccine to prevent it, and there is no medication to treat it. The best way protection we have against norovirus is good hand washing.

Always wash your hands after using the bathroom or changing diapers, before and after handling food, and before eating.

Norovirus can be found in the stool before you start showing any symptoms, and for as long as 2 weeks after you are feeling better.

Washing your hands well and frequently—especially if you think you could have been exposed to norovirus—is extremely important.

If you get sick, do not prepare food for others. This is important for people working in the food services industry because they come into contact with the food of so many other people. If you have a stomach bug—even if you aren't sure it's norovirus—recommendations are that you not return to preparing food for others for at least 2 to 3 days after you are feeling better. Good hand washing and hygiene practices are even more important in these environments where outbreaks can occur so easily.

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5 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Norovirus: Burden of Norovirus Illness in the U.S. Published 2019.

  2. Centers for Disease Control and Prevention. Norovirus: Symptoms. Published 2018.

  3. Centers for Disease Control and Prevention. Norovirus: Transmission. Published 2018.

  4. National Institute of Diabetes and Digestive and Kidney Diseases. Symptoms & Causes of Viral Gastroenteritis (“Stomach Flu”). Published 2018.

  5. National Institute of Diabetes and Digestive and Kidney Diseases. Treatment of Viral Gastroenteritis (“Stomach Flu”). Published 2018.