Effects of water, sanitation, handwashing and nutritional interventions on soil-transmitted helminth infections in young children: A cluster-randomized controlled trial in rural Bangladesh.

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TitleEffects of water, sanitation, handwashing and nutritional interventions on soil-transmitted helminth infections in young children: A cluster-randomized controlled trial in rural Bangladesh.
Publication TypeJournal Article
AuthorsErcumen A, Benjamin-Chung J, Arnold BF, Lin A, Hubbard AE, Stewart C, Rahman Z, Parvez SM, Unicomb L, Rahman M, Haque R, Colford JM, Luby SP
Abbrev. JournalPLoS Negl Trop Dis
JournalPLoS neglected tropical diseases
Year of Publication2019
Volume13
Issue5
Paginatione0007323
Publication Languageeng
KeywordsBangladesh, Children, Cluster randomized trial, MDA, Soil-transmitted helminth (STH), WaSH intervention
Abstract

BACKGROUND: Soil transmitted helminths (STH) infect >1.5 billion people. Mass drug administration (MDA) effectively reduces infection; however, there is evidence for rapid reinfection and risk of potential drug resistance. We conducted a randomized controlled trial in Bangladesh (WASH Benefits, NCT01590095) to assess whether water, sanitation, hygiene and nutrition interventions, alone and combined, reduce STH in a setting with ongoing MDA.

METHODOLOGY/PRINCIPAL FINDINGS: In 2012-2013, we randomized 720 clusters of 5551 pregnant women into water treatment, sanitation, handwashing, combined water+sanitation+handwashing (WSH), nutrition, nutrition+WSH (N+WSH) or control arms. In 2015-2016, we enrolled 7795 children, aged 2-12 years, of 4102 available women for STH follow-up and collected stool from 7187. We enumerated STH infections with Kato-Katz. We estimated intention-to-treat intervention effects on infection prevalence and intensity. Participants and field staff were not blinded; laboratory technicians and data analysts were blinded. Prevalence among controls was 36.8% for A. lumbricoides, 9.2% for hookworm and 7.5% for T. trichiura. Most infections were low-intensity. Compared to controls, the water intervention reduced hookworm by 31% (prevalence ratio [PR] = 0.69 (0.50,0.95), prevalence difference [PD] = -2.83 (-5.16,-0.50)) but did not affect other STH. Sanitation improvements reduced T. trichiura by 29% (PR = 0.71 (0.52,0.98), PD = -2.17 (-4.03,-0.38)), had a similar borderline effect on hookworm and no effect on A. lumbricoides. Handwashing and nutrition interventions did not reduce any STH. WSH and N+WSH reduced hookworm prevalence by 29-33% (WSH: PR = 0.71 (0.52,0.99), PD = -2.63 (-4.95,-0.31); N+WSH: PR = 0.67 (0.50,0.91), PD = -3.00 (-5.14,-0.85)) and marginally reduced A. lumbricoides. Effects on infection intensity were similar.

CONCLUSIONS/SIGNIFICANCE: In a low-intensity infection setting with MDA, we found modest but sustained hookworm reduction from water treatment and combined WSH interventions. Impacts were more pronounced on STH species with short vs. long-term environmental survival. Our findings suggest possible waterborne transmission for hookworm. Water treatment and sanitation improvements can augment MDA to interrupt STH transmission.

TRIAL REGISTRATION: NCT01590095.

PubMed URL

http://www.ncbi.nlm.nih.gov/pubmed/31050672?dopt=Abstract

DOI10.1371/journal.pntd.0007323
Link to full texthttps://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0007323