title: Rhinoviruses are a major cause of wheezing and hospitalization in children less than 2 years of age.
abstract: BACKGROUND
  Human rhinoviruses (HRV) are now considered major respiratory pathogens. We sought to determine whether HRV are a cause of wheezing and/or hospitalization in children <2 years old.
  
  
  METHODS
  A polymerase chain reaction assay was used to screen for HRV infection in 4 categories of children <2 years old: (1) with symptoms of respiratory tract disease without wheezing; (2) with wheezing with or without other symptoms; (3) who were asymptomatic and; (4) who had a respiratory specimen submitted to a diagnostic laboratory. All specimens were collected between January and December 2004. Phylogenetic analyses were performed on most HRV isolates.
  
  
  RESULTS
  Twenty-eight (17%) of 165 children with symptoms of respiratory infection without wheezing; 21 (26.3%) of 80 children with wheezing; 3 (3%) of 93 asymptomatic children; and 47 (23.3%) of 202 children with specimens submitted to the diagnostic laboratory tested positive for HRV. The difference between the rates of infection in the asymptomatic group and in each of the 3 other categories was statistically significant (P </= 0.01). Among HRV-positive children with samples submitted to the diagnostic laboratory, 55% were hospitalized, which was similar to that observed for respiratory syncytial virus (52.7%) among children of a similar age group and time period (P = 0.85). Diverse groups of HRV were circulating during the 1-year study period.
  
  
  CONCLUSIONS
  HRV are important pathogens among children <2 years old and are responsible for a significant proportion of wheezing this age group. The hospitalization rates of HRV-positive children seem to be similar to that of respiratory syncytial virus.
authors.affiliation: Division of Infectious Diseases, Yale University School of Medicine, New Haven, CT.
authors.forename: Zofia
authors.initials: Z
authors.lastname: Piotrowska
authors.forename: Marietta
authors.initials: M
authors.lastname: Vázquez
authors.forename: Eugene D
authors.initials: ED
authors.lastname: Shapiro
authors.forename: Carla
authors.initials: C
authors.lastname: Weibel
authors.forename: David
authors.initials: D
authors.lastname: Ferguson
authors.forename: Marie L
authors.initials: ML
authors.lastname: Landry
authors.forename: Jeffrey S
authors.initials: JS
authors.lastname: Kahn
mesh_terms: D003627:Data Interpretation, Statistical; D006760:Hospitalization; D006801:Humans; D007223:Infant; D017720:Molecular Epidemiology; D010802:Phylogeny; D010850:Picornaviridae Infections / Q000503:physiopathology / Q000821:virology*; D012135:Respiratory Sounds / Q000209:etiology*; D012141:Respiratory Tract Infections / Q000503:physiopathology / Q000821:virology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012229:Rhinovirus / Q000235:genetics / Q000302:isolation & purification*; D017423:Sequence Analysis, RNA