Background Helminth and protozoan infections affect more than 1 billion children globally. Improving water quality, sanitation, handwashing, and nutrition could be more sustainable control strategies for parasite infections than mass drug administration, while providing other quality of life benefits. Methods and findings We enrolled geographic clusters of pregnant women in rural western Kenya into a cluster-randomized controlled trial (ClinicalTrials.gov NCT01704105) that tested 6 interventions: water treatment, improved sanitation, handwashing with soap, combined water treatment, sanitation, and handwashing (WSH), improved nutrition, and combined WSH and nutrition (WSHN). We assessed intervention effects on parasite infections by measuring Ascaris lumbricoides , Trichuris trichiura , hookworm, and Giardia duodenalis among children born to the enrolled pregnant women (index children) and their older siblings. After 2 years of intervention exposure, we collected stool specimens from 9,077 total children aged 2 to 15 years in 622 clusters, including 2,346 children in an active control group (received household visits but no interventions), 1,117 in the water treatment arm, 1,160 in the sanitation arm, 1,141 in the handwashing arm, 1,064 in the WSH arm, 1,072 in the nutrition arm, and 1,177 in the WSHN arm. In the control group, 23% of children were infected with A . lumbricoides , 1% with T . trichiura , 2% with hookworm, and 39% with G . duodenalis . The analysis included 4,928 index children (median age in years: 2) and 4,149 older siblings (median age in years: 5); study households had an average of 5 people, <10% had electricity access, and >90% had dirt floors. Compared to the control group, Ascaris infection prevalence was lower in the water treatment arm (prevalence ratio [PR]: 0.82 [95% CI 0.67, 1.00], p = 0.056), the WSH arm (PR: 0.78 [95% CI 0.63, 0.96], p = 0.021), and the WSHN arm (PR: 0.78 [95% CI 0.64, 0.96], p = 0.017). We did not observe differences in Ascaris infection prevalence between the control group and the arms with the individual interventions sanitation (PR: 0.89 [95% CI 0.73, 1.08], p = 0.228), handwashing (PR: 0.89 [95% CI 0.73, 1.09], p = 0.277), or nutrition (PR: 86 [95% CI 0.71, 1.05], p = 0.148). Integrating nutrition with WSH did not provide additional benefit. Trichuris and hookworm were rarely detected, resulting in imprecise effect estimates. No intervention reduced Giardia . Reanalysis of stool samples by quantitative polymera...

Improved sanitation has been associated with a reduced prevalence of soil-transmitted helminth (STH) infection and has been hypothesized to prevent fecal contamination from spreading throughout the household environment. We evaluated the effect of providing households with a pit latrine with a plastic slab and drophole cover, child feces management tools, and associated behavioral messaging on reducing STH eggs in household soil. We collected soil samples from 2107 households (898 control and 1209 improved sanitation intervention households) that were enrolled in the WASH Benefits cluster randomized controlled trial in rural Kenya and performed a post-intervention analysis after two years of intervention exposure. Following a pre-specified analysis plan, we combined all households that received the sanitation intervention into one group for comparison to control households. The prevalence of STH eggs in soil was 18.9% in control households and 17.0% in intervention households. The unadjusted prevalence ratio of total STH eggs in the intervention groups compared to the control group was 0.94 (95% CI: 0.78–1.13). The geometric mean concentration was 0.05 eggs/g dry soil in control households and intervention households. Unadjusted and adjusted models gave similar results. We found use of a shared latrine, presence of a roof over the sampling area, and the number of dogs owned at baseline was associated with an increased prevalence of STH eggs in soil; the presence of a latrine that was at least 2 years old and a latrine with a covered drophole was associated with a reduction in the prevalence of STH eggs in soil. Soil moisture content was also associated with an increased prevalence of STH eggs in soil. Our results indicate that an intervention designed to increase access to improved latrines and child feces management tools may not be enough to impact environmental occurrence of STH in endemic areas where latrine coverage is already high.

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...