title: Exclusive breastfeeding protects against bacterial colonization and day care exposure to otitis media.
abstract: OBJECTIVE
  We followed a cohort (N = 306) of infants at well-baby visits in two suburban pediatric practices to assess the relation of exclusive breastfeeding, and other environmental exposures, to episodes of acute otitis media (AOM) and otitis media with effusion (OME).
  
  
  METHODS
  Detailed prospective information about the exclusiveness of breastfeeding, parental smoking, day care attendance, and family history was obtained at scheduled clinic visits. Tympanometric and otoscopic examinations were used in the diagnosis of otitis media (OM). Nasopharyngeal cultures were performed at 1-6 months, and at 8, 10, 12, 15, 18, and 24 months of age to detect colonization with middle-ear pathogens.
  
  
  RESULTS
  Between 6 and 12 months of age, cumulative incidence of first OM episodes increased from 25% to 51% in infants exclusively breastfed and from 54% to 76% in infants formula-fed from birth. Peak incidence of AOM and OME episodes was inversely related to rates of breastfeeding beyond 3 months of age. A twofold elevated risk of first episodes of AOM or OME was observed in exclusively formula-fed infants compared with infants exclusively breast-fed for 6 months. In the logistic regression analysis, formula-feeding was the most significant predictor of AOM and OME episodes, although age at colonization with middle-ear pathogens and day care (outside the home) were significant competing risk factors. A hazard health model suggested additionally that breastfeeding, even for short durations (3 months), reduced onset of OM episodes in infancy.
  
  
  CONCLUSIONS
  Modifiable factors in the onset of AOM and OME episodes during the first 2 years of life include early age at colonization (</=3 months of age), day care outside the home, and not being breastfed.
authors.affiliation: Department of Pediatrics, Children's Hospital, School of Medicine and Biomedical Sciences, State University of New York, Buffalo, NY 14209, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Duffy
authors.forename: H
authors.initials: H
authors.lastname: Faden
authors.forename: R
authors.initials: R
authors.lastname: Wasielewski
authors.forename: J
authors.initials: J
authors.lastname: Wolf
authors.forename: D
authors.initials: D
authors.lastname: Krystofik
mesh_terms: D000208:Acute Disease; D000328:Adult; D000367:Age Factors; D000704:Analysis of Variance; D001942:Breast Feeding; D002656:Child Day Care Centers; D015331:Cohort Studies; D015169:Colony Count, Microbial; D005260:Female; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000009:adverse effects; D007231:Infant, Newborn; D016015:Logistic Models; D008297:Male; D009305:Nasopharynx / Q000382:microbiology; D010033:Otitis Media / Q000517:prevention & control*; D010034:Otitis Media with Effusion / Q000517:prevention & control*; D016016:Proportional Hazards Models; D012008:Recurrence; D012307:Risk Factors