Influenza-associated pneumonia in children hospitalized with laboratory-confirmed influenza, 2003-2008

Pediatr Infect Dis J. 2010 Jul;29(7):585-90. doi: 10.1097/inf.0b013e3181d411c5.


Background: Pneumonia is one of the most common complications in children hospitalized with influenza. We describe hospitalized children with influenza-associated pneumonia and associated risk indicators.

Methods: Through Emerging Infections Program Network population based surveillance, children aged <18 years hospitalized with laboratory confirmed influenza with a chest radiograph during hospitalization were identified during the 2003-2008 influenza seasons. A case with radiologically confirmed influenza-associated pneumonia was defined as a child from the surveillance area hospitalized with: (1) laboratory-confirmed influenza and (2) evidence of new pneumonia on chest radiograph during hospitalization. Hospitalized children with pneumonia were compared with those without pneumonia by univariate and multivariate analysis.

Results: Overall, 2992 hospitalized children with influenza with a chest radiograph were identified; 1072 (36%) had influenza-associated pneumonia.When compared with children hospitalized with influenza without pneumonia, hospitalized children with influenza-associated pneumonia were more likely to require intensive care unit admission (21% vs. 11%, P < 0.01), develop respiratory failure (11% versus 3%, P < 0.01), and die(0.9% vs. 0.3% P 0.01). In multivariate analysis, age 6 to 23 months(adjusted OR: 2.1, CI: 1.6 -2.8), age 2 to 4 years (adjusted OR: 1.7, CI:1.3-2.2), and asthma (adjusted OR: 1.4, CI: 1.1-1.8) were significantly associated with influenza-associated pneumonia.

Conclusions: Hospitalized children with influenza-associated pneumonia were more likely to have a severe clinical course than other hospitalized children with influenza, and children aged 6 months to 4 years and those with asthma were more likely to have influenza-associated pneumonia.Identifying children at greater risk for influenza-associated pneumonia will inform prevention and treatment strategies targeting children at risk for influenza complications.

MeSH terms

  • Adolescent
  • Age Factors
  • Asthma / complications
  • Child
  • Child, Preschool
  • Female
  • Hospitalization*
  • Humans
  • Infant
  • Infant, Newborn
  • Influenza A virus / isolation & purification*
  • Influenza, Human / complications*
  • Male
  • Pneumonia, Bacterial / complications
  • Pneumonia, Bacterial / epidemiology*
  • Pneumonia, Bacterial / mortality
  • Pneumonia, Bacterial / pathology
  • Radiography, Thoracic
  • Respiratory Insufficiency / epidemiology
  • Risk Factors