Rotavirus is a virus that causes gastroenteritis (inflammation of the stomach and intestines). The rotavirus disease causes severe watery diarrhea, often with vomiting, fever, and abdominal pain. In babies and young children, it can lead to dehydration (loss of body fluids). Rotavirus is the leading cause of severe diarrhea in infants and young children worldwide. Globally, it causes more than a half a million deaths each year in children younger than 5 years of age.
Rotavirus was also the leading cause of severe diarrhea in U.S. infants and young children before rotavirus vaccine was introduced for U.S. infants in 2006. Prior to that, almost all children in the United States were infected with rotavirus before their 5th birthday. Each year in the United States in the pre-vaccine period, rotavirus was responsible for more than 400,000 doctor visits; more than 200,000 emergency room visits; 55,000 to 70,000 hospitalizations; and 20 to 60 deaths in children younger than 5 years of age.