title: Adolescent asthma after rhinovirus and respiratory syncytial virus bronchiolitis.
abstract: OBJECTIVE
  Asthma risk is increased after bronchiolitis in infancy. Recent studies have suggested that the risk may be dependent on the causative virus. The aim of the study was to evaluate the asthma risk in adolescence in subjects hospitalized for rhinovirus or respiratory syncytial virus (RSV) bronchiolitis in infancy.
  
  
  METHODS
  At the median age of 16.5 years, a questionnaire was sent to 96 study subjects hospitalized for bronchiolitis at <24 months of age and since then prospectively followed-up. Sixty-seven (70%) returned the fulfilled questionnaire. RSV and rhinovirus etiology of bronchiolitis had been studied in serum and respiratory samples obtained on admission in infancy. The occurrence of asthma was compared between former bronchiolitis patients and population controls recruited for this study in adolescence.
  
  
  RESULTS
  Doctor-diagnosed asthma was present in 30% of former bronchiolitis patients and in 5% of controls (OR 7.9, 95% CI 3.3-19.3). The respective figures for self-reported asthma were 64% and 11% (OR 14.7, 95% CI 7.2-30.0). Self-reported asthma was more common in the former rhinovirus than RSV patients (83.3% vs. 47.6%, P = 0.023, mixed infections included; 81.3% vs. 50%, P = 0.067, mixed infections excluded).
  
  
  CONCLUSIONS
  Patients hospitalized for RSV and rhinovirus bronchiolitis at <24 months of age had an increased asthma risk at 15-18 years of age compared with population controls. Within the former bronchiolitis group, the risk of self-reported asthma was higher after non-RSV versus RSV and after rhinovirus versus non-rhinovirus bronchiolitis.
authors.affiliation: Department of Pediatrics, Kuopio University and Kuopio University Hospital, Kuopio, Finland.
authors.forename: Marja
authors.initials: M
authors.lastname: Ruotsalainen
authors.forename: Mari K
authors.initials: MK
authors.lastname: Hyvärinen
authors.forename: Eija
authors.initials: E
authors.lastname: Piippo-Savolainen
authors.forename: Matti
authors.initials: M
authors.lastname: Korppi
mesh_terms: D000293:Adolescent; D001249:Asthma / Q000453:epidemiology*; D001990:Bronchiolitis, Viral / Q000453:epidemiology* / Q000821:virology; D016022:Case-Control Studies; D005260:Female; D005387:Finland / Q000453:epidemiology; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D008297:Male; D010850:Picornaviridae Infections / Q000453:epidemiology*; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology*; D012136:Respiratory Syncytial Viruses; D012229:Rhinovirus; D012307:Risk Factors; D011795:Surveys and Questionnaires