title: Population-based surveillance for hospitalizations associated with respiratory syncytial virus, influenza virus, and parainfluenza viruses among young children.
abstract: OBJECTIVE
  Respiratory syncytial virus (RSV), influenza virus, and parainfluenza viruses (PIV) cause significant morbidity in young children. Although only influenza virus infection and illness is currently vaccine-preventable, vaccines are under development for RSV and PIV. We established a prospective, active population-based surveillance network to provide precise estimates of hospitalization rates for viral acute respiratory illness (ARI) in young children and to measure the potential impact of enhanced vaccine usage on these rates.
  
  
  METHODS
  Prospective, active population-based surveillance was conducted in young children who were hospitalized for ARI from October 1, 2000, to September 30, 2001, in Monroe County, New York (Rochester area) and Davidson County, Tennessee (Nashville area). Eligible children younger than 5 years were those who resided in surveillance counties and were hospitalized for febrile or acute respiratory illness. Viral culture and polymerase chain reaction identified viruses from nasal and throat samples obtained from all surveillance children. We measured population-based rates of hospitalization for RSV, influenza virus, and PIV as well as demographic, clinical, and risk factor assessment for each virus.
  
  
  RESULTS
  Of 812 eligible hospital admissions, 592 (73%) children were enrolled. Of the enrolled children, RSV was identified in 20%, influenza in 3%, PIV in 7%, other respiratory viruses in 36%, and no detectable virus in 39%. Population-based rates of ARI hospitalizations in children younger than 5 years were 18 per 1000. Virus-positive hospitalization rates per 1000 children were 3.5 for RSV, 1.2 for PIV, and 0.6 for influenza virus. Younger age (particularly <1 year), black and Hispanic race/ethnicity, male gender, and presence of chronic underlying illness were associated with higher hospitalization rates.
  
  
  CONCLUSIONS
  This study confirms that children younger than 5 years and particularly children younger than 1 year have a high burden of hospitalization from RSV, influenza, and PIV. The enhanced use of influenza vaccine and the development of RSV and PIV vaccines have the potential to reduce markedly the pediatric morbidity from ARIs.
authors.affiliation: National Immunization Program, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. miwane@cdc.gov
authors.forename: Marika K
authors.initials: MK
authors.lastname: Iwane
authors.forename: Kathryn M
authors.initials: KM
authors.lastname: Edwards
authors.forename: Peter G
authors.initials: PG
authors.lastname: Szilagyi
authors.forename: Frances J
authors.initials: FJ
authors.lastname: Walker
authors.forename: Marie R
authors.initials: MR
authors.lastname: Griffin
authors.forename: Geoffrey A
authors.initials: GA
authors.lastname: Weinberg
authors.forename: Charmaine
authors.initials: C
authors.lastname: Coulen
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Poehling
authors.forename: Laura P
authors.initials: LP
authors.lastname: Shone
authors.forename: Sharon
authors.initials: S
authors.lastname: Balter
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Hall
authors.forename: Dean D
authors.initials: DD
authors.lastname: Erdman
authors.forename: Karen
authors.initials: K
authors.lastname: Wooten
authors.forename: Benjamin
authors.initials: B
authors.lastname: Schwartz
mesh_terms: D017677:Age Distribution; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007251:Influenza, Human / Q000453:epidemiology*; D008297:Male; D009518:New York / Q000453:epidemiology; D009975:Orthomyxoviridae / Q000302:isolation & purification; D010252:Paramyxoviridae / Q000302:isolation & purification; D018184:Paramyxoviridae Infections / Q000453:epidemiology*; D011159:Population Surveillance; D011446:Prospective Studies; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology*; D012136:Respiratory Syncytial Viruses / Q000302:isolation & purification; D012307:Risk Factors; D013714:Tennessee / Q000453:epidemiology; D014765:Viral Vaccines
chemical_list: D014765:Viral Vaccines