Norovirus was responsible for about 20% of acute gastroenteritis seen in children seeking medical attention for the condition, according to a study published March 21 in The New England Journal of Medicine
For the study, Norovirus and Medically Attended Gastroenteritis in U.S. Children, researchers conducted active surveillance of laboratory-confirmed cases of norovirus among children aged 5 years or younger with acute gastroenteritis in hospitals, outpatient clinics, and emergency departments during 2009 and 2010.
Data showed that 21% of children seeking medical attention for acute gastroenteritis in 2009 (22%) and 2010 (20%) had norovirus. In contrast, rotovirus was confirmed in only 12% of children presenting with acute symptoms during these years.
When researchers extrapolated the findings for this population to the US at large, they found that norovirus infections are associated with nearly 1 million health care visits per year. They estimate that by their fifth birthday, 1 in 278 US children are hospitalized for norovirus infection, 1 in 14 are seen in the emergency department, and 1 in 6 are seen by outpatient care providers.
As uptake of rotavirus vaccines continues to reduce the incidence of that infection, the study authors note, norovirus infection has become the leading cause of medically attended acute gastroenteritis among US children younger than 5 years.