May also be called: Norwalk virus; Norwalk-like virus

A norovirus (nor-uh-VY-rus) is a group of related viruses that can cause gastroenteritis (inflammation of the stomach and intestines).

More to Know

Noroviruses are the most common cause of gastroenteritis in the United States, affecting more than 20 million people each year. Infection with a norovirus can cause nausea, vomiting, diarrhea, stomach cramps, fatigue, and mild fever.

Noroviruses are highly contagious and often spread quickly in crowded, closed places like cruise ships, childcare centers, schools, and nursing homes. Noroviruses are spread through the vomit and feces of infected individuals. People can become infected with a norovirus by eating contaminated food, drinking contaminated water, or coming into contact with infected people or objects.

There is no specific treatment for norovirus infection. Although the condition is rarely serious, it can cause dehydration, which can lead to serious complications, especially in young children, the elderly, and people with weakened immune systems.

Keep in Mind

In most cases, norovirus infections will get better in a few days without treatment. People infected with a norovirus should make sure to drink plenty of fluids to prevent dehydration. Washing hands well and often can help stop the spread of noroviruses.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.