People with norovirus are usually most contagious from the time diarrhea or vomiting starts until about 2 to 3 days after symptoms stop, even though the virus can stay in the stool for two weeks or more. That means someone can still pass the virus on even after feeling better.
Norovirus spreads very easily through tiny amounts of stool or vomit that get on hands, food, water, or surfaces. Because only a small amount of virus is enough to cause infection, close contact at home, school, daycare, or long-term care facilities can quickly lead to outbreaks
To lower the risk of spreading norovirus, it is important to stay home while sick and for about 72 hours after symptoms end, especially for children in school and adults who work around food or vulnerable people. Frequent handwashing with soap and water and careful cleaning of bathrooms and other soiled areas are key, as alcohol gel alone is not enough.
Anyone with severe, persistent, or worsening symptoms, especially babies, older adults, or people with other health problems, should be assessed by a general practitioner, gastroenterologist, or infectious disease specialist. Self-medication, particularly with antidiarrheals or antibiotics, should be avoided without medical advice.