Cases of rotavirus-associated acute gastroenteritis have declined since the introduction of rotavirus vaccines, but the burden of norovirus-associated acute gastroenteritis in children remains to be assessed.
Dr Daniel Payne and colleagues conducted active surveillance for laboratory-confirmed cases of norovirus among children younger than 5 years of age with acute gastroenteritis in hospitals, emergency departments, and outpatient clinical settings.
The children resided in 1 of 3 U.S. counties during the years 2009 and 2010.
Fecal specimens were tested for norovirus and rotavirus.
|The virus was also detected in 4% of healthy controls in 2009|
|New England Journal of Medicine|
The researchers calculated population-based rates of norovirus-associated acute gastroenteritis, and reviewed billing records to determine medical costs.
These data were extrapolated to the U.S. population of children younger than 5 years of age.
The team detected norovirus in 21% of young children seeking medical attention for acute gastroenteritis in 2009 and 2010, with norovirus detected in 22% in 2009, and 20% in 2010.
The virus was also detected in 4% of healthy controls in 2009.
The research team identified rotavirus in 12% of children with acute gastroenteritis in 2009 and 2010.
The respective rates of hospitalization, emergency department visits, and outpatient visits for the norovirus were 9, 147, and 368 per 10,000 children younger than 5 years of age in 2009, and 6, 134, and 260 per 10,000 in 2010.
The estimated cost per episode was $3,918, $435, and $151, respectively, in 2009.
Nationally, the team estimate that the average numbers of annual hospitalizations, emergency department visits, and outpatient visits due to norovirus infection in 2009 and 2010 among U.S. children in this age group exceeded 14,000, 281,000, and 627,000, respectively.
The cost was more than $273 million in treatment each year.
Dr Payne and colleagues concluded, "Since the introduction of rotavirus vaccines, norovirus has become the leading cause of medically attended acute gastroenteritis in U.S. children and is associated with nearly 1 million health care visits annually."