29Background. Helminth and protozoan infections affect >1 billion children globally. Improved 30 water, sanitation, handwashing, and nutrition could be more sustainable control strategies for 31 parasite infections than mass drug administration (MDA), while providing other quality of life 32 benefits.
33Methods and Findings. We enrolled geographic clusters of pregnant women into a cluster-34 randomized controlled trial that tested six interventions: disinfecting drinking water(W),
35improved sanitation(S), handwashing with soap(H), combined WSH, improved nutrition(N), and 36 combined WSHN. We assessed intervention effects on parasite infections by measuring Ascaris 37 lumbricoides, Trichuris trichiura, hookworm, and Giardia duodenalis among individual children 38 born to enrolled mothers and their older siblings (ClinicalTrials.gov NCT01704105). We collected 39 stool specimens from 9077 total children in 622 clusters, including 2346 children in control, 40 1117 in water, 1160 in sanitation, 1141 in handwashing, 1064 in WSH, 1072 in nutrition, and 41 1177 in WSHN. In the control group, 23% of children were infected with Ascaris lumbricoides, 42 1% with Trichuris trichuria, 2% with hookworm and 39% with Giardia duodenalis. After two 43 years of intervention exposure, Ascaris infection prevalence was 18% lower in the water 44 treatment arm (95% confidence interval (CI) 0%, 33%), 22% lower in the WSH arm (CI 4%, 37%), 45 and 22% lower in the WSHN arm (CI 4%, 36%) compared to control. Individual sanitation, 46 handwashing, and nutrition did not significantly reduce Ascaris infection on their own, and 47 integrating nutrition with WSH did not provide additional benefit. Trichuris and hookworm were 48 rarely detected, resulting in imprecise effect estimates. No intervention reduced Giardia. 49 Reanalysis of stool samples by quantitative polymerase chain reaction (qPCR) confirmed the 50 reductions in Ascaris infections measured by microscopy in the WSH and WSHN groups. Lab 51 technicians and data analysts were blinded to treatment assignment, but participants and 52 3 sample collectors were not blinded. The trial was funded by the Bill & Melinda Gates Foundation 53 and USAID. 54 Conclusions. Our results suggest integration of improved water quality, sanitation, and 55 handwashing could contribute to sustainable control strategies for Ascaris infections, 56 particularly in similar settings with recent or ongoing deworming programs. Water treatment 57 alone was similarly effective to integrated WSH, providing new evidence that drinking water 58 should be given increased attention as a transmission pathway for Ascaris. 59 60 61 countries 62 63 64 estimated to affect 1.45 billion people(1), while Giardia has been cited as the most common 69 enteropathogen in low-income countries(2). STH and Giardia infections can result in poor 70 absorption of nutrients and weight loss(3,4). There is some evidence that STH and Giardia 71 infections, even when asymptomatic, may contribute to growth faltering and impaired cognitive 72 develop...