Breast feeding as a determinant of severity in shigellosis. Evidence for protection throughout the first three years of life in Bangladeshi children.

Little is known about the effect of breast feeding upon the severity of illness due to specific diarrheal pathogens. Using a systematically sampled and evaluated population of children aged less than 3 years, who attended a diarrheal disease hospital in Bangladesh, the authors performed a case-control study that assessed whether breast feeding reduces the severity of illness in shigellosis. From 540 children presenting with shigellosis between 1980-1982, they created a group of cases (n = 53) with severe illness and controls (n = 487) with non-severe illness. Overall, the odds ratio relating breast feeding to the severity of shigellosis (0.49, p = 0.01) suggested a substantial mitigating effect of breast feeding upon clinical severity. The high degree of protection against severe shigellosis was evident for breast-fed children up to 35 months of age, as well as for children at high risk for death because of severe malnutrition or measles. Because shigellosis continues to account for substantial morbidity and mortality in children in developing countries, the results support prolonged breast feeding in these settings.