title: Influenza-like illness responsible for severe exacerbations in asthmatic children during H1N1 pandemic: a survey before vaccination.
abstract: BACKGROUND
  Asthma seems to be the more prevalent underlying condition in patients hospitalized for H1N1-related flu.
  
  
  METHODS
  A prospective survey was conducted during the early phase of H1N1 pandemic in France in asthmatic children before vaccination to assess whether severe exacerbations in childhood asthma are associated with influenza-like illness (ILI, the definition of H1N1-related flu in a pandemic). Eight pediatricians in primary care distributed in three localities (Paris, south suburb, and west suburb) conducted the survey (4 weeks/locality from week 36 to 47). At each visit, the pediatrician filled a questionnaire entering the information regarding asthma treatment, severe exacerbation (at least 3 days' use of systemic corticosteroids), and ILI (temperature ≥37.8°C, cough, and/or sore throat, in the absence of a known cause other than influenza) during the past 3 weeks.
  
  
  RESULTS
  The survey included 1155 asthmatic children (mean age [SD]: 7.5 years [4.1]); almost all visits were scheduled (99%). A severe exacerbation was recorded in 121 children [10.5%; 95% confidence interval (CI): 8.7-12.2%], which was concomitant with ILI in 20 children (16.5%; 95% CI: 9.9-23.2%), whereas 1034 children did not exhibit any exacerbation. In these latter children, 40 ILI were observed (3.9%; 95% CI: 2.7-5.0%), which constituted a significantly lesser percentage as compared with children with both exacerbation and ILI (p < .0001). This result remained significant in each locality. Overall, 60/1155 (5.2%; 95% CI: 3.9-6.5%) asthmatic children had an ILI.
  
  
  CONCLUSIONS
  Our survey shows that severe exacerbation and ILI are strongly associated during the H1N1 pandemic in asthmatic children.
authors.affiliation: Cabinet La Berma, Antony, France.
authors.forename: Bruno
authors.initials: B
authors.lastname: Mahut
authors.forename: Luc
authors.initials: L
authors.lastname: Refabert
authors.forename: Valentine
authors.initials: V
authors.lastname: Marchac
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Iniguez
authors.forename: Guillaume
authors.initials: G
authors.lastname: Aubertin
authors.forename: Aline
authors.initials: A
authors.lastname: Tamalet
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Lebras
authors.forename: Corinne
authors.initials: C
authors.lastname: Troadec
authors.forename: Gilles
authors.initials: G
authors.lastname: Chatellier
authors.forename: Christophe
authors.initials: C
authors.lastname: Delclaux
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D001249:Asthma / Q000150:complications* / Q000188:drug therapy / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007252:Influenza Vaccines / Q000008:administration & dosage; D007251:Influenza, Human / Q000150:complications* / Q000453:epidemiology* / Q000517:prevention & control; D008137:Longitudinal Studies; D008297:Male; D058873:Pandemics; D010297:Paris / Q000453:epidemiology; D013383:Suburban Population / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014611:Vaccination
chemical_list: D000305:Adrenal Cortex Hormones; D007252:Influenza Vaccines