title: Pneumonia and wheezing in the first year: An international perspective.
abstract: BACKGROUND
  The relationship between pneumonia and recurrent wheezing (RW) and the factors associated to pneumonia in wheezing and non-wheezing infants have not been compared between affluent and non-affluent populations.
  
  
  METHODS
  The International Study of Wheezing in Infants (EISL) is a large population-based cross-sectional study carried out in Latin America (LA) and Europe (EU). We used a validated questionnaire for identifying wheeze in the first year of life. The questionnaire also inquired about pneumonia diagnosis, together with other potentially related factors. Associations between both conditions and between potential risk/protective factors for pneumonia were tested by random-effects logit model and adjusting for all factors found previously associated to RW in this cohort.
  
  
  RESULTS
  Pneumonia and RW were strongly associated to each other in LA and EU (aOR 5.42; 95%CI: 4.87-6.04 and aOR 13.99; 95%CI: 9.61-20.36, respectively). Infant eczema was the most consistent risk factor of pneumonia in both continents, in the whole population and also among wheezers and non-wheezers (aOR ranging from 1.30; 95%CI: 1.11-1.52 to 2.65; 95%CI: 1.68-4.18); while breast feeding for at least 3 months was the most consistent protective factor (aOR ranging from 0.60; 95%CI: 0.51-0.71 to 0.76; 95%CI: 0.69-0.84). Factors associated to pneumonia were similar between continents among wheezers, but differed considerably among non-wheezers.
  
  
  CONCLUSIONS
  Pneumonia and RW are associated conditions sharing many risk/protective factors in EU and LA among wheezing infants, but not among non-wheezing infants. The association between pneumonia and RW could be due to shared pathophysiology or by diagnostic confusion between the two conditions.
authors: Paediatric Respiratory and Allergy Unit, "Virgen de la Arrixaca" University Children's Hospital, University of Murcia, Murcia, Spain.
authors: Luis
authors: L
authors: Garcia-Marcos
authors: Department of Paediatric Respiratory Medicine, Hospital El Pino, University of Santiago de Chile (USACH), Chile.
authors: Javier
authors: J
authors: Mallol
authors: Division of Allergy, Clinical Immunology and Rheumatology, Department of Paediatrics, Federal University of S, ã, o Paulo (UNIFESP), São Paulo, Brazil.
authors: Dirceu
authors: D
authors: Solé
authors: Princess Amalia Children's Clinic, Isala Klinieken, Zwolle, and UMCG Postgraduate School of Medicine, University Medical Centre Groningen, the Netherlands.
authors: Paul L P
authors: PL
authors: Brand
authors: Paediatric Respiratory and Allergy Unit, "Virgen de la Arrixaca" University Children's Hospital, University of Murcia, Murcia, Spain.
authors: Antonela
authors: A
authors: Martinez-Torres
authors: Paediatric Respiratory and Allergy Unit, "Virgen de la Arrixaca" University Children's Hospital, University of Murcia, Murcia, Spain.
authors: Manuel
authors: M
authors: Sanchez-Solis
mesh_terms: D001942:Breast Feeding; D003430:Cross-Sectional Studies; D003876:Dermatitis, Atopic / Q000453:epidemiology; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007223:Infant; D007843:Latin America / Q000453:epidemiology; D008297:Male; D011014:Pneumonia / Q000453:epidemiology*; D015995:Prevalence; D012135:Respiratory Sounds; D012307:Risk Factors; D011795:Surveys and Questionnaires
keywords: epidemiology; infant; pneumonia; wheezing