title: Risk factors for acute asthma in tropical America: a case-control study in the City of Esmeraldas, Ecuador.
abstract: BACKGROUND
  Despite the high asthma rates described in Latin America, asthma risk factors in poor urban settings are not well established. We investigated risk factors for acute asthma among Ecuadorian children.
  
  
  METHODS
  A matched case-control study was carried out in a public hospital serving a coastal city. Children with acute asthma were age- and sex-matched to non-asthmatics. A questionnaire was administered, and blood, as well as stool, and nasopharyngeal swabs were collected.
  
  
  RESULTS
  Sixty cases and 119 controls aged 5-15 were evaluated. High proportions of cases were atopic with population-attributable fractions for atopy of 68.5% for sIgE and 57.2% for SPT. Acute asthma risk increased with greater titers of mite IgE (3.51-50 kU/l vs. <0.70kU/l - OR 4.56, 95% CI 1.48-14.06, p = 0.008; >50kU/l vs. <0.70kU/l - OR 41.98, 95% CI: 8.97-196.39, p < 0.001). Asthma risk was significantly independently associated with bronchiolitis (adj. OR: 38.9, 95% CI 3.26-465), parental educational level (adj. OR 1.26, 95% CI: 1.08-1.46), and presence of sIgE (adj. OR: 36.7, 95% CI: 4.00-337), while a reduced risk was associated with current contact with pets (adj. OR: 0.07, 95% CI: 0.01-0.56). Rhinovirus infection was more frequent in cases (cases 35.6% vs. controls 7.8%, p = 0.002). None of the cases were on maintenance therapy with inhaled corticosteroids and most relied on emergency department for control.
  
  
  CONCLUSIONS
  A high proportion of children presenting to a public hospital with acute asthma were allergic to mite, particularly at high IgE titer. Poor asthma control resulted in overuse of emergency care.
authors.affiliation: Hospital 'Delfina Torres de la Concha', Esmeraldas, Esmeraldas Province, Ecuador.|Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador.|Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.
authors.forename: Cristina
authors.identifier: http://orcid.org/0000-0001-7924-518X
authors.initials: C
authors.lastname: Ardura-Garcia
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador.
authors.forename: Maritza
authors.initials: M
authors.lastname: Vaca
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador.
authors.forename: Gisela
authors.initials: G
authors.lastname: Oviedo
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sandoval
authors.affiliation: Asthma and Allergic Diseases Center, University of Virginia, Charlottesville, VA, USA.
authors.forename: Lisa
authors.initials: L
authors.lastname: Workman
authors.affiliation: Asthma and Allergic Diseases Center, University of Virginia, Charlottesville, VA, USA.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Schuyler
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY, USA.
authors.forename: Matthew S
authors.initials: MS
authors.lastname: Perzanowski
authors.affiliation: Asthma and Allergic Diseases Center, University of Virginia, Charlottesville, VA, USA.
authors.forename: Thomas A E
authors.initials: TA
authors.lastname: Platts-Mills
authors.affiliation: Laboratorio de Investigaciones FEPIS, Quinindé, Esmeraldas Province, Ecuador.|Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, UK.|Centro de Investigaciones en Enfermedades Infecciosas, Pontificia Universidad Católica del Ecuador, Quito, Ecuador.|Institute of Infection and Immunity, St George's University of London, London, UK.
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Cooper
mesh_terms: D000208:Acute Disease; D000293:Adolescent; D017677:Age Distribution; D000485:Allergens / Q000009:adverse effects / Q000276:immunology; D000818:Animals; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use; D001249:Asthma / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology* / Q000276:immunology; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D018450:Disease Progression; D004484:Ecuador / Q000453:epidemiology; D004636:Emergency Service, Hospital; D005260:Female; D006779:Hospitals, Public; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D007159:Immunologic Tests; D019570:Inhalation Exposure / Q000009:adverse effects; D019476:Insect Proteins / Q000276:immunology; D016015:Logistic Models; D008297:Male; D008925:Mites / Q000276:immunology; D015999:Multivariate Analysis; D016017:Odds Ratio; D011379:Prognosis; D012141:Respiratory Tract Infections / Q000453:epidemiology / Q000276:immunology / Q000821:virology; D012307:Risk Factors; D014504:Urban Health
chemical_list: D000485:Allergens; D018927:Anti-Asthmatic Agents; D015415:Biomarkers; D019476:Insect Proteins; D007073:Immunoglobulin E
keywords: Ecuador; acute asthma; atopy; tropics; urban