Influenza-Like Illness Responsible for Severe Exacerbations in Asthmatic Children During H1N1 Pandemic: A Survey Before Vaccination

• Published in: The Journal of asthma 2011-04, Vol.48 (3), p.224-227
• Main Authors: Mahut, Bruno, Refabert, Luc, Marchac, Valentine, Iniguez, Jean-Luc, Aubertin, Guillaume, Tamalet, Aline, Lebras, Marie-Noëlle, Troadec, Corinne, Chatellier, Gilles, Delclaux, Christophe
• Format: Article
• Language: English
• Subjects: Adrenal Cortex Hormones - therapeutic use; asthma; Asthma - complications; Asthma - drug therapy; Asthma - epidemiology; Child; Child, Preschool; childhood; exacerbation; Female; Hospitalization - statistics & numerical data; Humans; influenza; Influenza A Virus, H1N1 Subtype; Influenza Vaccines - administration & dosage; Influenza, Human - complications; Influenza, Human - epidemiology; Influenza, Human - prevention & control; Longitudinal Studies; Male; Pandemics; Paris - epidemiology; Suburban Population - statistics & numerical data; Surveys and Questionnaires; Vaccination
• ISSN: 0277-0903; 1532-4303
• DOI: 10.3109/02770903.2011.555032

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.