Summary: This article, published in the Journal of Infectious Diseases in October 2009, documents further investigation into the result of the Kisumu Breastfeeding Study, in which infants of HIV-infected mothers who received antiretroviral therapy experienced high rates of diarrhea at weaning. To address this problem, mothers in the study were given safe water storage vessels, hygiene education, and bleach for household water treatment. The authors compared the incidence of diarrhea in infants enrolled before and after implementation of the intervention.