title: Wheezing conditions in early childhood: prevalence and risk factors in the city of São Paulo, Brazil.
abstract: OBJECTIVE
  To investigate the prevalence and risk factors for wheezing disorders in early childhood in São Paulo, Brazil, the largest metropolitan area of South America.
  
  
  METHODS
  A population-based cross-sectional survey of 1132 children aged 6-59 months was carried out between 1995 and 1996 to obtain information on recent wheezing and on independent variables such as demographic, socioeconomic, environmental, maternal and nutritional variables and immunization status. Intestinal parasitic infections were diagnosed using standard techniques. Multiple unconditional logistic regression was used to describe associations between outcome and independent variables.
  
  
  RESULTS
  The prevalence of recent wheezing (one or more reported episodes in the past 12 months) was 12.5%; 93% of children with wheezing were also reported to have a medical diagnosis of asthma. Recent wheezing was associated with low per capita income, poor quality of housing, day-care attendance, low birth weight and infection with intestinal helminths.
  
  
  CONCLUSIONS
  Wheezing in early childhood in São Paulo, although more common than in most developing countries, remains less prevalent than in urban areas of industrialized countries. Low income and conditions associated with poverty (poor housing, low birth weight and parasitic infections) are some of the main risk factors for wheezing disorders among young children in this city.
authors.affiliation: Department of Nutrition, School of Public Health, University of São Paulo, Avenue Dr. Arnaldo 715, 01246-904, São Paulo, Brazil.
authors.forename: Maria Helena D
authors.initials: MH
authors.lastname: Benício
authors.forename: Marcelo U
authors.initials: MU
authors.lastname: Ferreira
authors.forename: Maria Regina A
authors.initials: MR
authors.lastname: Cardoso
authors.forename: Sílvia C
authors.initials: SC
authors.lastname: Konno
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Monteiro
mesh_terms: D001249:Asthma / Q000150:complications / Q000453:epidemiology*; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D003906:Developing Countries; D005260:Female; D006306:Health Surveys; D006801:Humans; D007223:Infant; D008297:Male; D015995:Prevalence; D012135:Respiratory Sounds / Q000209:etiology*; D012307:Risk Factors; D012959:Socioeconomic Factors; D014329:Tropical Climate; D014504:Urban Health / Q000706:statistics & numerical data*