What is the major cause of stomach flu?
Noroviruses are the main cause of nonbacterial gastroenteritis (stomach flu). It is not caused by the influenza virus (cold /flu virus). It is the second most frequent cause of illness behind only the common cold. There are as many as 23 million cases of gastroenteritis in the United States each year (Center for Disease Control report). Studies estimates that noroviruses account for more than 90% of nonbacterial gastroenteritis outbreaks. Also, noroviruses cause the majority of traveler’s diarrhea cases.
