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

• Published in: PLoS medicine 2019-06, Vol.16 (6), p.e1002841
• Main Authors: Pickering, Amy J, Njenga, Sammy M, Steinbaum, Lauren, Swarthout, Jenna, Lin, Audrie, Arnold, Benjamin F, Stewart, Christine P, Dentz, Holly N, Mureithi, MaryAnne, Chieng, Benard, Wolfe, Marlene, Mahoney, Ryan, Kihara, Jimmy, Byrd, Kendra, Rao, Gouthami, Meerkerk, Theodora, Cheruiyot, Priscah, Papaiakovou, Marina, Pilotte, Nils, Williams, Steven A, Colford, Jr, John M, Null, Clair
• Format: Article
• Language: English
• Subjects: Adolescent; Animals; Ascariasis; Ascaris; Biology and Life Sciences; Charities; Child; Child nutrition; Child, Preschool; Children; Children & youth; Clinical trials; Cognitive development; Combined water; Control; Demographic aspects; Dirt; Disease transmission; Drinking water; Ecology and Environmental Sciences; Engineering; Environmental engineering; Epidemiology; Feces; Female; Funding; Giardia; Giardiasis; Giardiasis - epidemiology; Giardiasis - prevention & control; Giardiasis - transmission; Hand Disinfection - methods; Hand Disinfection - trends; Handwashing; Health aspects; Health education; Helminthiasis; Helminths; Household sanitation; Households; Humans; Infection; Infection control; Infections; Intervention; Low income groups; Male; Medical research; Medicine and Health Sciences; Microscopy; Nutrition; Nutrition Assessment; Parasitic diseases; Polymerase chain reaction; Poverty; Pregnancy; Pregnant women; Prevention; Protozoa; Public health; Public relations; Quality of life; Randomization; Research centers; Retirement benefits; Rural Population - trends; Sanitation; Sanitation - methods; Sanitation - trends; Siblings; Soil - parasitology; Supervision; Sustainability; Technicians; Treatment Outcome; Water; Water Purification - methods; Water quality; Water treatment; Women
• ISSN: 1549-1676; 1549-1277; 1549-1676
• DOI: 10.1371/journal.pmed.1002841

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. 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, 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 polymerase chain reaction confirmed the red