title: Influenza-associated pneumonia in children hospitalized with laboratory-confirmed influenza, 2003-2008.
abstract: 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.
authors.affiliation: Epidemic Intelligence Service, Centers forDisease Control and Prevention , Atlanta, GA, USA. fdawood@cdc.gov
authors.forename: Fatimah S
authors.initials: FS
authors.lastname: Dawood
authors.forename: Anthony
authors.initials: A
authors.lastname: Fiore
authors.forename: Laurie
authors.initials: L
authors.lastname: Kamimoto
authors.forename: Mackenzie
authors.initials: M
authors.lastname: Nowell
authors.forename: Arthur
authors.initials: A
authors.lastname: Reingold
authors.forename: Kem
authors.initials: K
authors.lastname: Gershman
authors.forename: James
authors.initials: J
authors.lastname: Meek
authors.forename: James
authors.initials: J
authors.lastname: Hadler
authors.forename: Kathryn E
authors.initials: KE
authors.lastname: Arnold
authors.forename: Patricia
authors.initials: P
authors.lastname: Ryan
authors.forename: Ruth
authors.initials: R
authors.lastname: Lynfield
authors.forename: Craig
authors.initials: C
authors.lastname: Morin
authors.forename: Joan
authors.initials: J
authors.lastname: Baumbach
authors.forename: Shelley
authors.initials: S
authors.lastname: Zansky
authors.forename: Nancy M
authors.initials: NM
authors.lastname: Bennett
authors.forename: Ann
authors.initials: A
authors.lastname: Thomas
authors.forename: William
authors.initials: W
authors.lastname: Schaffner
authors.forename: David
authors.initials: D
authors.lastname: Kirschke
authors.forename: Lyn
authors.initials: L
authors.lastname: Finelli
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001249:Asthma / Q000150:complications; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D009980:Influenza A virus / Q000302:isolation & purification*; D007251:Influenza, Human / Q000150:complications*; D008297:Male; D018410:Pneumonia, Bacterial / Q000150:complications / Q000453:epidemiology* / Q000401:mortality / Q000473:pathology; D013902:Radiography, Thoracic; D012131:Respiratory Insufficiency / Q000453:epidemiology; D012307:Risk Factors