Norovirus is now the leading cause of acute gastroenteritis requiring medical care among U.S. children younger than 5 years of age, according to a report published online March 20 in the New England Journal of Medicine.
Now that rotavirus vaccines have dramatically reduced the number of acute gastroenteritis cases attributable to that organism, norovirus infections have taken over the lead in causing the disorder in the young U.S. pediatric population. Norovirus is responsible for an estimated 1 million health care visits each year for this age group, at an estimated cost approaching $300 million, said Daniel C. Payne, Ph.D., of the National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, and his associates.
Dr. Daniel Payne
"According to our estimation, by their fifth birthday, 1 in 278 U.S. 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," the investigators noted.
They studied the epidemiology of the infection because now that candidate norovirus vaccines are in development, "there is a need to directly measure the pediatric health care burden of norovirus-associated gastroenteritis."
Dr. Payne and his colleagues analyzed data from the New Vaccine Surveillance Network, which collects information on the medical care of children residing near Rochester, N.Y.; Nashville, Tenn.; and Cincinnati – a catchment population exceeding 141,000 children under age 5.
The researchers prospectively assessed cases of acute gastroenteritis treated at hospitals, emergency departments, and outpatient clinics during two successive 12-month surveillance periods between October 2008 and September 2010. There were 1,077 cases the first year and 820 the second year; the data from these were compared with data from 806 age-matched children attending well-child visits, who served as a control group.
The disease burden of norovirus infection was "consistently high" during both years, accounting for 20%-22% of cases of acute gastroenteritis. Norovirus was detected in 4% of healthy controls in 2009. The overall rate of medical attention for the infection was highest – 47% – among children aged 6-18 months, Dr. Payne and his associates reported (N. Engl. J. Med. 2013;368:1121-30).
This study was supported by the CDC. Dr. Payne reported that he did not have any conflicts of interest relevant to this study. His coauthors reported ties to GlaxoSmithKline, Merck, and Luminex Molecular Diagnostics.