What you need to know about norovirus

Norovirus is a type of viral infection that causes gastroenteritis — an inflammation of the lining of the intestines that leads to nausea, vomiting and diarrhea. It’s extremely contagious, and outbreaks are common.

What are the symptoms of norovirus? How long do symptoms last?

The most common symptoms of norovirus are nausea, vomiting, diarrhea and abdominal pain. Sometimes people may have fevers as well. Typically, symptoms last 24 to 72 hours.

How long is norovirus contagious?

People are most contagious while they’re sick and up to two days after symptoms subside.

How can I prevent norovirus?

The best way to prevent infection or to prevent spread to others is to practice good hand hygiene. Wash hands before eating or before preparing food and after using the restroom. Norovirus can also be transmitted by contaminated food, so it’s recommended to wash fruits and vegetables thoroughly before consuming. Shellfish should be cooked thoroughly. (There have been recent outbreaks of norovirus related to raw oysters.)

Who’s at risk for getting norovirus?

Because norovirus is so contagious, outbreaks occur commonly where people live in close proximity (nursing homes, restaurants, cruise ships, schools, childcare centers). While most people recover from norovirus, certain groups are at higher risk for complications — usually dehydration from profuse diarrhea or inability to keep down fluids. Groups that may be at higher risk are infants, the elderly and those who are immunocompromised.

Is the norovirus the same as the stomach flu?

The term "stomach flu" is usually a generic term for gastroenteritis (an illness that causes vomiting and diarrhea). Many viruses, including norovirus, can cause gastroenteritis. It’s important to note that norovirus is not related to the influenza virus (the "flu").

How do I know I’m sick from norovirus and not something else, like Shigella or other bacteria?

Many different types of viruses and bacteria can cause gastroenteritis, so it can often be difficult to distinguish between norovirus and these other types of infection. Since most of these infections usually resolve on their own in a few days, testing for specific pathogens is usually not necessary.

How do I treat norovirus at home? Should I go to the doctor for norovirus?

If you (or a child) are sick with norovirus, you should stay home from work or school while you’re sick and for two days after symptoms resolve. In most instances, symptoms improve on their own in a few days and it’s not necessary to see a doctor. Because it’s a virus, antibiotics aren’t effective against norovirus, and there’s no specific treatment. It must run its course. It’s recommended to contact your health care provider if symptoms last beyond a few days, if there are signs of dehydration (inability to keep down liquids, low urine output, lethargy) or for severe symptoms (such as bloody diarrhea or severe abdominal pain).