Viral gastroenteritis (Gastro-Enter-eye,tiss), also called stomach flu, gastric flu, and stomach virus, is an infection caused by a variety of viruses that results in vomiting & diarrhea. Viruses that are known to cause gastroenteritis include the genus Rotavirus, the genus Norovirus, the genus Sapovirus, the family Adenovirus, and the family Astrovirus. The genus Rotavirus is the most common cause of diarrhea and sickness among infants and children worldwide. The genus Norovirus or the species Norwalk virus is the leading cause of gastroenteritis among adults in America, causing greater than 90% of outbreaks. These localized epidemics typically occur when groups of people spend time in close physical proximity to each other, such as on cruise ships, in hospitals, schools or in restaurants. People may remain infectious even after their diarrhea has ended.