Norovirus Gastroenteritis: An Introduction
Norovirus gastroenteritis is an illness caused by a norovirus. The illness can result in
diarrhea, nausea, and vomiting. It is now thought that at least 50 percent of all foodborne outbreaks of gastroenteritis can be attributed to noroviruses.
Understanding Noroviruses
Noroviruses are a group of related RNA viruses that cause acute viral gastroenteritis (also known as the "
stomach flu") in humans. Norovirus was recently approved as the official genus name for the group of viruses previously described as "Norwalk-like viruses" (NLV).
Noroviruses are named after the original strain "Norwalk virus," which caused an outbreak of gastroenteritis in a school in Norwalk, Ohio, in 1968.
(Click Norovirus for more information on this group of related viruses.)
How Is Norovirus Gastroenteritis Spread?
Noroviruses are highly contagious and can spread easily from person to person. Noroviruses are found in the stool or vomit of infected people.
Norovirus transmission can happen in one of several ways, including:
- Eating foods or drinking liquids that are contaminated with norovirus
- Touching surfaces or objects contaminated with norovirus and then putting your hands in your mouth
- Having direct contact with another person who is infected and showing symptoms (for example, when caring for someone with the illness, or sharing foods or eating utensils with someone who is ill).
People infected with norovirus are usually contagious from the moment they begin feeling ill to at least 3 days after recovery. Some people may be contagious for as long as 2 weeks after recovery. Therefore, it is particularly important for people to use good hand washing and other hygienic practices after they have recently recovered from norovirus illness.