Effects of single and integrated water, sanitation, handwashing, and nutrition interventions on child soil-transmitted helminth and Giardia infections: A cluster-randomized controlled trial in rural Kenya

Abstract

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...

The WASH Benefits and SHINE trials: interpretation of WASH intervention effects on linear growth and diarrhoea

“…The combined WASH and water chlorination interventions reduced Ascaris infection by 18-22% but 18% of children who received the WASH interventions were still infected with Ascaris. 51 None of the WASH interventions reduced…”

“…Finally, 39% of mothers reported that their child had consumed soil in the previous week. 51 In the SHINE trial in Zimbabwe, the WASH intervention reduced maternal-reported child geophagia by 63% but 27% of children in the WASH group still ingested faecalcontaminated soil. The WASH inter vention had a very small effect on total parasite infections but had no effect on carriage of bacterial or viral enteropathogens using molecular diagnostics.…”

Intestinal Parasitic Infection and Its Associated Factors Among Primary School Students in Ethiopia; a Systematic Review and Meta-Analysis

“…More than 550 million school children live in areas where intestinal parasitic infections (IPI) are endemic with 450 million of the illnesses occurring in sub-Saharan Africa (2,(4)(5)(6)(7). Parasitic infections are among the most preventable neglected tropical infections in humans (8).…”

Ruminant Fecal Contamination of Drinking Water Introduced Post-Collection in Rural Kenyan Households

“…This study was conducted among households enrolled in a large-scale randomized controlled trial of water, sanitation, handwashing, and nutrition interventions in rural Kenya (WASH Benefits Kenya). The trial found that the water intervention (chlorination) improved microbial water quality as measured by E. coli, but none of the interventions reduced E. coli contamination on child hands or on sentinel toy balls [38], and none of the interventions reduced child diarrhea or improved child growth [39]. The study investigators concluded that the interventions were not able to sufficiently reduce fecal contamination in the household environment [40]; one potential explanation is that animal feces were a substantial source of fecal contamination in study households [38].…”