The impact of school water, sanitation, and hygiene improvements on infectious disease using serum antibody detection

• Type of Material: Article
• Authors: Anna N. Chard, Emory; Victoria Trinies, Emory; Delynn M. Moss, National Center for Emerging and Zoonotic Infectious Diseases; Howard Chang, Emory University; Seydou Doumbia, University of Bamako Faculty of Medicine; Patrick Lammie, Emory University; Matthew Freeman, Emory University
• Language: English
• Date: 2018-04-16
• Publisher: Public Library of Science
• Publication Version: Final Published Version
• Copyright Statement: © 2018 Public Library of science. All Rights Reserved.
• License: Creative Commons Creative Commons CC0 1.0 Universal
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pntd.0006418
• Title of Journal or Parent Work: PLoS Neglected Tropical Diseases
• ISSN: 1935-2727
• Volume: 12
• Issue: 4
• Start Page: e0006418
• End Page: e0006418
• Grant/Funding Information: This study was supported by the Dubai Cares Foundation (http://www.dubaicares.ae/en).; Funding was acquired by MCF (no grant number given).; The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
• Research Categories: Health Sciences, Public Health; Biology, Biostatistics

Abstract

Background: Evidence from recent studies assessing the impact of school water, sanitation and hygiene (WASH) interventions on child health has been mixed. Self-reports of disease are subject to bias, and few WASH impact evaluations employ objective health measures to assess reductions in disease and exposure to pathogens. We utilized antibody responses from dried blood spots (DBS) to measure the impact of a school WASH intervention on infectious disease among pupils in Mali. Methodology/Principal findings: We randomly selected 21 beneficiary primary schools and their 21 matched comparison schools participating in a matched-control trial of a comprehensive school-based WASH intervention in Mali. DBS were collected from 20 randomly selected pupils in each school (n = 807). We analyzed eluted IgG from the DBS using a Luminex multiplex bead assay to 28 antigens from 17 different pathogens. Factor analysis identified three distinct latent variables representing vector-transmitted disease (driven primarily by dengue), food/water-transmitted enteric disease (driven primarily by Escherichia coli and Vibrio cholerae), and person-to-person transmitted enteric disease (driven primarily by norovirus). Data were analyzed using a linear latent variable model. Antibody evidence of food/water-transmitted enteric disease (change in latent variable mean (β) = -0.24; 95% CI: -0.53, -0.13) and person-to-person transmitted enteric disease (β = -0.17; 95% CI: -0.42, -0.04) was lower among pupils attending beneficiary schools. There was no difference in antibody evidence of vector-transmitted disease (β = 0.11; 95% CI: -0.05, 0.33). Conclusions/Significance: Evidence of enteric disease was lower among pupils attending schools benefitting from school WASH improvements than students attending comparison schools. These findings support results from the parent study, which also found reduced incidence of self-reported diarrhea among pupils of beneficiary schools. DBS collection was feasible in this resource-poor field setting and provided objective evidence of disease at a low cost per antigen analyzed, making it an effective measurement tool for the WASH field.