Norovirus, a member of the Caliciviridae family, is a contagious RNA virus that causes gastroenteritis, a digestive system illness characterized by nausea, vomiting, and severe diarrhea. It's one of the most common causes of gastroenteritis, affecting people of all ages.

First identified in 1968 at a school in Ohio, norovirus can occur in summer or winter. This Caliciviridae virus can cause digestive disturbances and lead to acute gastroenteritis, an inflammation of the stomach and intestines. Symptoms in adults may include simultaneous diarrhea and vomiting.

As an RNA virus, norovirus undergoes mutations, resulting in different antigenic types. It spreads rapidly in enclosed and crowded environments such as schools, hospitals, restaurants, daycare centers, public transportation, or shopping malls, affecting all age groups. Its ability to survive in various environments means it can cause illness multiple times in the same individual.

Norovirus symptoms appear within 12 to 48 hours and can be severe. Norovirus outbreaks can lead to hospitalization. It is commonly transmitted through food and water and can cause infections in various parts of the body. The virus can survive on many surfaces for extended periods, leading to transmission through contact with these areas.

Recovery time varies depending on the individual's overall health and resilience, but the virus can be detected in stool samples for up to 6 weeks.