Background: Exclusive breast-feeding reduces the risk of respiratory illness in infants younger than 6 months of age in developing countries by approximately half. We evaluated the effect of exclusive breast-feeding on respiratory illness with fever (RIF) in Bangladeshi infants in the context of a randomized maternal influenza immunization trial.
Methods: Infants in a maternal vaccine trial in Dhaka, Bangladesh, were prospectively assessed at weekly intervals for 6 months after birth for breast-feeding practices and RIF. We estimated the risk of an RIF episode for infants who were exclusively breast-fed the prior week compared with infants not exclusively breast-fed the prior week using generalized estimating equations.
Results: We followed a total of 331 infants from birth to 24 weeks of age. The median weeks infants were exclusively breast-fed was 15 (interquartile range, 6–21). The adjusted independent odds of respiratory illness for exclusively breast-fed infants compared with nonexclusively breast-fed infants was 0.59 (95% confidence interval: 0.45–0.77) for an RIF episode. After adjusting for exclusive breast-feeding, we confirmed the previous report that maternal immunization with influenza vaccine had an independent protective effect against RIF (odds ratio, 0.72; 95% confidence interval: 0.55–0.93). No significant difference in the protective effect of exclusive breast-feeding was seen by maternal influenza immunization status.
Conclusions: Exclusive breast-feeding during the first 6 months of life and maternal immunization with influenza vaccine independently and substantially reduced respiratory illness with fever in infants.
From the *Center for Health Research-Northwest, Kaiser Permanente, Portland, OR; †Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD; ‡Cincinnati Children’s Hospital Medical Center, Cincinnati, OH; §Rollins School of Public Health, Emory University; ¶Center for Health Research-Southeast, Kaiser Permanente, Atlanta, GA; and ‖ICDDR, B, Dhaka, Bangladesh.
Accepted for publication December 06, 2012.
The Mother’s Gift project was supported by the Bill and Melinda Gates Foundation, United States Agency for International Development cooperative agreement HRN-A-0096–90006–00; Wyeth Pharmaceuticals Inc (Madison, NJ), the Thrasher Research Fund, Aventis Pasteur (Swiftwater, PA), ICDDR, B, and the Bloomberg School of Public Health at Johns Hopkins University (Baltimore, MD). ICDDR, B, acknowledges with gratitude the commitment of donors to the Centre’s research efforts. EH was supported by the Department of Health and Human Services, National Institutes of Health, National Eye Institute Training Grant Number EY 07127 Clinical Trials Training Program in Vision Research. The authors have no other funding or conflicts of interest to disclose.
Address for correspondence: Emily Henkle, PhD, MPH, Oregon Health & Science University, 3375 SW Terwilliger Ave, Portland, OR 97239. E-mail: firstname.lastname@example.org.