EXCLUSIVE BREAST-FEEDING PROTECTS AGAINST BACTERIAL-COLONIZATION AND DAY-CARE EXPOSURE TO OTITIS-MEDIA

Objective. We followed a cohort (N = 306) of infants at well-baby visi ts in two suburban pediatric practices to assess the relation of exclu sive 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 breastfe eding, parental smoking, day care attendance, and family history was o btained at scheduled clinic visits. Tympanometric and otoscopic examin ations 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. Res ults. Between 6 and 12 months of age, cumulative incidence of first OM episodes increased from 25% to 51% in infants exclusively breastfed a nd from 54% to 76% in infants formula-fed from birth. peak incidence o f 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 wi th infants exclusively breast-fed for 6 months. In the logistic regres sion analysis, formula-feeding was the most significant predictor of A OM and OME episodes, although age at colonization with middle-ear path ogens and day care (outside the home) were significant competing risk factors. A hazard health model suggested additionally that breastfeedi ng, even for short durations (3 months), reduced onset of OM episodes in infancy. Conclusions. Modifiable factors in the onset of AOM and OM E episodes during the first 2 years of life include early age at colon ization (less than or equal to 3 months of age), day care outside the home, and not being breastfed.