Norovirus: What to Know

Published: March 11, 2024
Barbara Young
By Barbara Young, PharmD

Norovirus is a virus that easily passes from person to person and can cause severe gastrointestinal (GI) illness. An estimated 21 million cases or more occur in the United States each year, including over 70,000 hospitalizations and 800 deaths.

What is norovirus?
Norovirus is a contagious virus that causes severe GI symptoms. It takes only a very small number of these viruses to cause infection. Although norovirus occurs year-round, it is most common in the winter months of November through April.

What are the symptoms of norovirus?
The most noted symptoms are nausea, vomiting, and diarrhea, but other complaints may include abdominal pain and cramping, muscle aches, headache, and chills. People who become dehydrated by the loss of body fluids from vomiting and diarrhea may also experience fast heartbeat, dizziness, and dry skin and mouth.

How does norovirus spread?
Norovirus can cause infection when the virus enters the mouth and GI system. This can happen several ways:

  • Eating or drinking contaminated food or beverages
  • Direct contact with an infected person or from their vomit or feces (poop)
  • Touching surface with the virus and getting it into your mouth via unwashed hands

This virus is easily spread among all age groups and may result in severe illness or hospitalization in the very young, elderly, and in those who are immunocompromised. Common settings for norovirus outbreaks are in hospitals and other healthcare facilities, schools, colleges, military barracks, cruise ships, and resorts.

What should I do to treat norovirus?
The most important goal in treating norovirus is to avoid dehydration from loss of body fluids. Therefore, you should drink plenty of liquids to replace fluid lost from vomiting and diarrhea. Experts recommend drinking oral rehydration solutions such as Pedialyte®, rather than sports drinks such as Gatorade® which can often worsen diarrhea. Contact a doctor or get medical attention if you have signs of dehydration such as: fainting, confusion, lack of urination, rapid heartbeat, or fast breathing.

How can I prevent getting norovirus?
The #1 way to prevent getting norovirus is by handwashing. You need to wash your hands carefully for at least 20 seconds with soap and running water. Alcohol-based hand rubs may or may not be helpful to remove the virus from your hands.

In settings with norovirus illness, clean surfaces (such as bathroom sinks, toilets, tables, chairs, beds, and desks) with a diluted bleach solution (5 to 25 tablespoons of household bleach in a gallon of water). Leave the solution on the surface for at least 5 minutes and then wash with soap and water. Be sure to wear disposable gloves when cleaning. Also be sure to wash contaminated laundry that may have feces or vomit and wash your hands carefully after handling this laundry.

Food should be prepared safely. Wash fruits and vegetables well and cook oysters and other shellfish thoroughly to an internal temperature of at least 145°F. Kitchen areas and utensils should be cleaned and sanitized regularly. People that have norovirus should not prepare or serve food while they are ill and for at least 2 days after their symptoms go away.

Most people recover from a norovirus infection within 5 to 10 days. It is important to maintain hydration by drinking plenty of fluids or rehydrating solutions, especially for young children and elderly people. Handwashing and other hygiene measures are important to prevent the spread of the virus in family and group living situations.

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