Thorax 65:1004-1009 doi:10.1136/thx.2009.115188
  • Paediatric lung disease

International prevalence of recurrent wheezing during the first year of life: variability, treatment patterns and use of health resources

  1. the EISL Study Group
  1. 1Department of Pediatric Respiratory Medicine, Hospital El Pino, University of Santiago de Chile (USACH), Santiago, Chile
  2. 2Pediatric Respiratory and Allergy Units, Virgen de la Arrixaca University Children's Hospital, University of Murcia, and CIBER of Epidemiology and Public Health (CIBERESP), Murcia, Spain
  3. 3Division of Allergy, Clinical Immunology and Rheumatology, Department of Pediatrics, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
  4. 4Department of Pediatric Pulmonology, Isala Clinic, Zwolle, The Netherlands
  1. Correspondence to Professor Javier Mallol, P O Box 23 Correo 9, Santiago, Chile; jmallol{at}
  • Received 11 February 2009
  • Accepted 29 July 2010
  • Published Online First 20 September 2010


Background Recurrent wheezing (RW) during the first year of life is a major cause of respiratory morbidity worldwide, yet there are no studies on its prevalence at an international level. A study was undertaken to determine the prevalence of RW in infants during their first year of life in affluent and non-affluent localities.

Methods This international population-based study was performed in random samples of infants aged 12–15 months from 17 centres in Latin America and Europe. It uses a validated questionnaire answered by parents at the primary care health clinics where infants attend for growth/development monitoring and/or vaccine administration.

Results Among the 30 093 infants surveyed, 45.2% (95% CI 44.7% to 45.8%) had at least one episode of wheezing and 20.3% (95% CI 19.8% to 20.7%) had RW. The mean prevalence of RW in Latin American and European centres was 21.4% (95% CI 20.9% to 21.9%) and 15.0% (95% CI 14.0% to 15.9%), respectively (p<0.001). There was significant morbidity associated with RW in terms of severe episodes (59.4%), visits to the emergency department (71.1%) and hospital admissions (26.8%); 46.1% used inhaled corticosteroids.

Conclusions The prevalence of RW in infants during the first year of life is high and varies between localities. A significant proportion of infants progress to a more severe condition which results in high use of health resources (visits to emergency department and hospitalisations). The prevalence of RW is lower and less severe in European than in Latin American centres, suggesting there is a higher risk for the disease in developing areas.


  • Members of the EISL Study Group are listed at the end of the paper.

  • EISL Study Group Manuel Baeza-Bacab, (México, Mérida); Álvaro Madeiro Leite, Olívia Costa Bessa (Brazil Fortaleza); Elaine Xavier Prestes (Brazil, Belem); Emanuel Sarinho, Décio Medeiros (Brazil, Recife); Paulo Camargos, María Jussara Fernández-Fontes, Wilson Rocha (Brazil, Bello Horizonte); Dirceu Solé, Caroline Della Bianca (Brazil, São Paulo); Nelson Rosario Herberto Chong (Brazil, Curitiba); Gilberto B Fischer (Brazil, Porto Alegre); Eduardo Cepeda (Colombia, Barranquilla); Oscar Aldrey, Arnaldo Capriles (Venezuela, Caracas); Javier Mallol, Viviana Aguirre, Alejandro Gallardo (Chile, Santiago); Mario Calvo (Chile, Valdivia); Luis García-Marcos, Antonela Martínez-Torres, Virginia Pérez-Fernández, (España, Murcia); Carlos González-Díaz, Andrés González Hermosa (España, Bilbao); Ángel López-Silvarrey Varela (España, La Coruña); María Morales Suárez-Varela (España, Valencia); Paul L P Brand, Chantal A N Visser (Zwolle, The Netherlands).

  • Competing interests None.

  • Patient consent Parents or guardians who agreed to participate in the study filled in the questionnaire after reading and signing a fully informed written consent form.

  • Ethics approval This study was conducted with the approval of the Scientific Ethics Committee, Chilean Ministry of Health, Southern Metropolitan Area of Santiago de Chile (Chile), the Ethics Committee of the University of Murcia (Spain) for all Spanish centres, and the respective Ethics Committees for the rest of the participating centres.

  • Provenance and peer review Not commissioned; externally peer reviewed.