Lead author, Katherine Poehling, M.D., assistant professor of Pediatrics at the Monroe Carell Jr. Children's Hospital at Vanderbilt, says a four-year study of children seen in pediatrician's offices and children's hospitals, including Vanderbilt Children's, proved the flu has a tremendous impact on all children up to 5 years old.
"People in hospitals have long suspected that influenza brought in a lot of young children, but what we didn't realize is the number of outpatient visits the virus creates. We went to pediatrician's offices and tested children 6 months to 5 years and found that in a moderate flu season, one in six children seen actually had the flu. It was one in 16 during a mild flu season," said Poehling.
The flu was confirmed by nasal swab in 160 of the more than 3,300 children who had respiratory symptoms. While younger children accounted for most of the hospitalizations - 80 percent were under 2 years old -- the most surprising finding was that outpatient visits associated with the flu were up to 250 times more common than hospitalizations.
"And despite the common occurrence, few children were specifically diagnosed as having influenza," Poehling said. "That means as a community and a nation, we were not fully recognizing the burden of this potentially preventable virus."
The data on the burden of influenza in young children led the Advisory Committee on Immunization Practices (ACIP) to recommend that the CDC advise flu vaccinations for all children 6 months to 5 years.