title: Virologically confirmed population-based burden of hospitalization caused by respiratory syncytial virus, adenovirus, and parainfluenza viruses in children in Hong Kong.
abstract: OBJECTIVE
  To determine virologically confirmed hospitalization rates associated with respiratory syncytial virus (RSV), adenovirus, and parainfluenza viruses in Hong Kong children.
  
  
  METHODS
  All patients <18 years of age living on Hong Kong Island (within Hong Kong SAR) admitted for a febrile acute respiratory infection to 1 of the 2 public hospitals on 1 fixed day of the week between October 2003 and September 2006 were prospectively recruited. Hong Kong Island has a known population denominator and these 2 hospitals managed 72.5% of all general pediatric admissions for this population. Nasopharyngeal aspirates were tested for RSV, adenovirus, and parainfluenzae types 1, 2, and 3 by direct antigen detection and culture.
  
  
  RESULTS
  The annual hospitalization rate for RSV in infants <6 months of age was 233.4 to 311.2 per 10,000. Parainfluenza type 3 had a hospitalization rate of 27.3 to 122.8 per 10,000 in the 1 to <2 years group. Adenovirus was associated with significant hospitalization in those 6 months to 1 year (25.9-77.8 per 10,000), and in those 2 to <5 years (38.1-59.2 per 10,000). The mean duration of hospitalization for RSV was 4.04 ± 2.61 days, significantly longer than the 3.12 ± 1.41 days for adenovirus and the 2.93 ± 2.54 days for parainfluenza infections (P = 0.013 and P = 0.038, respectively).
  
  
  CONCLUSIONS
  We documented that the overall pediatric hospitalization burden of RSV was high and comparable to that of influenza. The burden for all the studied viruses was mainly in previously healthy children <5 years of age.
authors.affiliation: Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, People's Republic of China.
authors.forename: Susan S
authors.initials: SS
authors.lastname: Chiu
authors.forename: Kwok-Hung
authors.initials: KH
authors.lastname: Chan
authors.forename: Hong
authors.initials: H
authors.lastname: Chen
authors.forename: Betty W
authors.initials: BW
authors.lastname: Young
authors.forename: Wilina
authors.initials: W
authors.lastname: Lim
authors.forename: Wilfred Hing-Sang
authors.initials: WH
authors.lastname: Wong
authors.forename: J S Malik
authors.initials: JS
authors.lastname: Peiris
mesh_terms: D000257:Adenoviridae Infections / Q000453:epidemiology* / Q000473:pathology; D000260:Adenoviruses, Human / Q000302:isolation & purification; D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D008297:Male; D009305:Nasopharynx / Q000821:virology; D018184:Paramyxoviridae Infections / Q000453:epidemiology* / Q000473:pathology; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology* / Q000473:pathology; D018113:Respiratory Syncytial Virus, Human / Q000302:isolation & purification; D018108:Respirovirus / Q000302:isolation & purification