Illnesses caused by norovirus infections have several names, including:
- Stomach flu. This "stomach flu" is not related to the flu (or influenza), which is a respiratory illness caused by influenza virus.
- Viral gastroenteritis. This is the most common name for illness caused by norovirus. Gastroenteritis refers to an inflammation of the stomach and intestines.
- Acute gastroenteritis.
- Non-bacterial gastroenteritis.
- Food poisoning (although there are other causes of food poisoning).
- Calicivirus infection.
Noroviruses are not related to bacteria and parasites that can cause gastrointestinal illnesses. In addition, this is not a "new" virus, but interest in it is growing as more is learned about how frequently the virus causes illness in people.
Noroviruses are highly contagious and can spread easily from person to person. They are found in the stool or vomit of infected people. Transmission can happen in one of several ways, including:
- Eating food or drinking liquids that are contaminated with the virus
- 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 three days after recovery. Some people may be contagious for as long as two weeks after recovery. Therefore, it is particularly important for people to use good handwashing and other hygienic practices after they have recently recovered from a norovirus illness.