The importance of an uncontaminated water supply and proper sanitation in controlling enteric infections, as well as contributing to poverty eradication, has been recognized by the international community. Although sanitation appears to be no less effective as a public health measure than water supply improvements, targets for improving sanitation worldwide are not being met, and there is a lack of rigorous evidence demonstrating the effectiveness of sanitation programs in preventing disease in large populations. Barreto et al. evaluated the impact of a sanitation program implemented throughout the city of Salvador in Bahia State, Brazil, on infection with Ascaris lumbricoides, Trichuris trichuria, and Giardia duodenalis in two cross-sectional studies of children aged 1