Selections from Journal Watch Pediatrics and Adolescent medicine Copyright © 2006 Massachusetts Medical Society. All rights reserved.

Influenza: the burden of disease in children

▸ The burden of influenza infection in children is unknown. In a multisite cohort study, investigators prospectively enrolled children younger than 5 years who either had been hospitalized or who had presented to clinics and emergency departments in 2000–2004 with symptoms of acute respiratory tract infection or fever. Infection was confirmed by a positive polymerase-chain-reaction assay or viral culture for influenza A or B.

Among 2797 hospitalized children, 6% had laboratory-confirmed influenza. Infection was significantly more common in infants (age range, 0–5 months; 49%) than in older children (age range, 24–59 months; 20%). Among children aged 6 months and older, fewer than 25% of parents reported that their child had been vaccinated against influenza. Only 28% of confirmed cases had discharge diagnoses of influenza. The annual hospitalization rate associated with influenza averaged 0.9 per 1000 children and was significantly higher in infants than in older children (4.5 vs. 0.3 cases per 1000).

Among 1742 children seen in clinics or EDs, 16% had confirmed influenza. Infection was significantly less common in infants than in older children (7% vs. 52%). Among children aged 6 years and older, fewer than 30% of parents reported that their child had been vaccinated. Only 17% of confirmed cases had discharge diagnoses of influenza. During the 2002–2003 influenza season, influenza infection was associated with 50 clinic and 6 …