title: Influenza and parainfluenza associated pediatric ICU morbidity.
abstract: OBJECTIVE
  To investigate if morbidity in young children admitted to a pediatric intensive care unit (PICU with a laboratory proven diagnosis of influenza and parainfluenza infection) had increased.
  
  
  METHODS
  Retrospective study from January 2003 through December 2009 was carried out. Every child in the PICU with a laboratory-confirmed influenza or parainfluenza infection was included.
  
  
  RESULTS
  18 influenza (influenza A =13 and influenza B = 5) and 17 parainfluenza admissions were identified over the 7-year period. Parainfluenza type 3 (n = 9) was the commonest subtype of parainfluenza infection. The median age of children admitted with influenza was higher than parainfluenza (4.5 vs 1.7 years, p = 0.044). Admissions associated with proven influenza and parainfluenza infections accounted for 2% of PICU annual admissions. There was only one death in 2003. 51% of these patients required ventilatory support, 45% received systemic corticosteroids, and 91% received initial broad spectrum antibiotic coverage. Bacterial co-infections were identified in 25% of these patients. The incidence of influenza admissions had not increased significantly in 2009 (H1N1 pandemic) when compared with 2003 (SARS epidemic) (p = 0.3). There were only two PICU cases of pandemic H1N1 in 2009 and both survived. The annual incidence of severe PICU cases of influenza and parainfluenza were 0.94 and 0.88 per 100,000 children per annum, respectively.
  
  
  CONCLUSIONS
  Pandemic H1N1, influenza and parainfluenza viruses may be associated with significant childhood morbidity and PICU admissions.
authors.affiliation: Department of Pediatrics, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong SAR, China. ehon@hotmail.com
authors.forename: Kam Lun
authors.initials: KL
authors.lastname: Hon
authors.forename: Ting Fan
authors.initials: TF
authors.lastname: Leung
authors.forename: Kam Lau
authors.initials: KL
authors.lastname: Cheung
authors.forename: Pak Cheung
authors.initials: PC
authors.lastname: Ng
authors.forename: Paul Kay Sheung
authors.initials: PK
authors.lastname: Chan
mesh_terms: D002675:Child, Preschool; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000453:epidemiology*; D015278:Intensive Care Units, Pediatric / Q000706:statistics & numerical data*; D008297:Male; D010224:Parainfluenza Virus 3, Human; D018184:Paramyxoviridae Infections / Q000453:epidemiology*; D012141:Respiratory Tract Infections / Q000453:epidemiology* / Q000821:virology; D010253:Respirovirus Infections / Q000453:epidemiology; D012189:Retrospective Studies