Quantitative assessment of exposure to fecal contamination in urban environment across nine cities in low-income and lower-middle-income countries and a city in the United States

• Type of Material: Article
• Authors: Yuke Wang, Emory University; Wolfgang Mairinger, Emory University; Suraja J. Raj, Emory University; Habib Yakubu, Emory University; Casey Siesel, Emory University; Jamie Green, Emory University; Sarah Durry, Emory University; George Joseph, The World Bank; Mahbubur Rahman, International Centre for Diarrhoeal Disease Research, Bangladesh; Nuhu Amin, International Centre for Diarrhoeal Disease Research, Bangladesh; Md. Zahidul Hassan, Data Analysis & Technical Assistance Ltd; James Wicken, WaterAid; Dany Dourng, WaterAid; Eugene Larbi, Training Research and Networking for Development (TREND); Lady Asantewa B. Adomako, Training Research and Networking for Development (TREND); Ato Kwamena Senayah, Training Research and Networking for Development (TREND); Benjamin Doe, Training Research and Networking for Development (TREND); Richard Buamah, Kwame Nkrumah University Science & Technology; Joshua Nii Noye Tetteh-Nortey, Kumasi Metropolitan Assembly; Gagandeep Kang, Christian Medical College; Arun Karthikeyan, Christian Medical College; Sheela Roy, Christian Medical College; Joe Brown, Georgia Institute of Technology; Bacelar Muneme, WE Consult; Seydina O. Sene, Initiative Prospective Agricole et Rurale (IPAR); Benedict Tuffuor, Training Research and Networking for Development (TREND); Richard K. Mugambe, Makerere University; Najib Lukooya Bateganya, Kampala Capital City Author; Trevor Surridge, Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH; Grace Mwanza Ndashe, Lusaka City Council; Kunda Ndashe, Lusaka Apex Medical University; Radu Ban, Bill & Melinda Gates Foundation; Alyse Schrecongost, Bill & Melinda Gates Foundation; Christine Moe, Emory University
• Language: English
• Date: 2021-11-26
• Publisher: Elsevier
• Publication Version: Final Published Version
• Copyright Statement: © 2021 The Authors. Published by Elsevier B.V.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.scitotenv.2021.151273
• Title of Journal or Parent Work: Science of the Total Environment
• Volume: 806
• Issue: Pt 3
• Start Page: 151273
• End Page: 151273
• Grant/Funding Information: We are grateful to Erica Coppel and Louis Boorstin for their insights in developing the SaniPath Study and the Bill & Melinda Gates Foundation for funding and supporting our work (grant OPP1016151).
• Keywords: Life Sciences & Biomedicine; Accra; Vegetables; Pathway; Escherichia coli; Environmental Sciences & Ecology; WASH; LLMIC; Fecal; Exposure assessment; Science & Technology; Transmission; Environmental Sciences; Multi-city; Young children; Ghana; Neighborhood; Water
• Research Categories: Health Sciences, Epidemiology; Engineering, Environmental; Health Sciences, Hygiene; Environmental Sciences

Abstract

Background During 2014 to 2019, the SaniPath Exposure Assessment Tool, a standardized set of methods to evaluate risk of exposure to fecal contamination in the urban environment through multiple exposure pathways, was deployed in 45 neighborhoods in ten cities, including Accra and Kumasi, Ghana; Vellore, India; Maputo, Mozambique; Siem Reap, Cambodia; Atlanta, United States; Dhaka, Bangladesh; Lusaka, Zambia; Kampala, Uganda; Dakar, Senegal. Objective Assess and compare risk of exposure to fecal contamination via multiple pathways in ten cities. Methods In total, 4053 environmental samples, 4586 household surveys, 128 community surveys, and 124 school surveys were collected. E. coli concentrations were measured in environmental samples as an indicator of fecal contamination magnitude. Bayesian methods were used to estimate the distributions of fecal contamination concentration and contact frequency. Exposure to fecal contamination was estimated by the Monte Carlo method. The contamination levels of ten environmental compartments, frequency of contact with those compartments for adults and children, and estimated exposure to fecal contamination through any of the surveyed environmental pathways were compared across cities and neighborhoods. Results Distribution of fecal contamination in the environment and human contact behavior varied by city. Universally, food pathways were the most common dominant route of exposure to fecal contamination across cities in low-income and lower-middle-income countries. Risks of fecal exposure via water pathways, such as open drains, flood water, and municipal drinking water, were site-specific and often limited to smaller geographic areas (i.e., neighborhoods) instead of larger areas (i.e., cities). Conclusions Knowledge of the relative contribution to fecal exposure from multiple pathways, and the environmental contamination level and frequency of contact for those “dominant pathways” could provide guidance for Water, Sanitation, and Hygiene (WASH) programming and investments and enable local governments and municipalities to improve intervention strategies to reduce the risk of exposure to fecal contamination.