Quantitative assessment of fecal contamination in multiple environmental sample types in urban communities in Dhaka, Bangladesh using SaniPath microbial approach

• Type of Material: Article
• Authors: Nuhu Amin, International Center for Diarrhoeal Disease Research; Mahbubur Rahman, International Centre for Diarrhoeal Disease Research; Suraja Raj, Emory University; Shahjahan Ali, International Centre for Diarrhoeal Disease Research; Jamie Green, Emory University; Shimul Das, International Centre for Diarrhoeal Disease Research; Solaiman Doza, International Centre for Diarrhoeal Disease Research; Momenul H Mondol, International Centre for Diarrhoeal Disease Research; Yuke Wang, Emory University; Christine Moe, Emory University
• Language: English
• Date: 2019-12-16
• Publisher: Public Library Science
• Publication Version: Final Published Version
• Copyright Statement: © 2019 Amin et al.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1371/journal.pone.0221193
• Title of Journal or Parent Work: PLOS One
• Volume: 14
• Issue: 12
• Start Page: e0221193
• End Page: e0221193
• Grant/Funding Information: The study was financially supported by the Bill & Melinda Gates Foundation (grant no. 00010161) through the Rollins School of Public Health at Emory University.
• Keywords: SAFETY; EXPOSURE; QUALITY; STREET FOOD VENDORS; DRINKING-WATER; VEGETABLES; DEVELOPING-COUNTRIES; Science & Technology; ANIMAL FECES; Science & Technology - Other Topics; Multidisciplinary Sciences; ESCHERICHIA-COLI; HANDS
• Research Categories: Health Sciences, General; Health Sciences, Hygiene; Health Sciences, Medicine and Surgery

Abstract

This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Rapid urbanization has led to a growing sanitation crisis in urban areas of Bangladesh and potential exposure to fecal contamination in the urban environment due to inadequate sanitation and poor fecal sludge management. Limited data are available on environmental fecal contamination associated with different exposure pathways in urban Dhaka. We conducted a cross-sectional study to explore the magnitude of fecal contamination in the environment in low-income, high-income, and transient/floating neighborhoods in urban Dhaka. Ten samples were collected from each of 10 environmental compartments in 10 different neighborhoods (4 low-income, 4 high-income and 2 transient/floating neighborhoods). These 1,000 samples were analyzed with the IDEXX-Quanti-Tray technique to determine most-probable-number (MPN) of E. coli. Samples of open drains (6.91 log10 MPN/100 mL), surface water (5.28 log10 MPN/100 mL), floodwater (4.60 log10 MPN/100 mL), produce (3.19 log10 MPN/serving), soil (2.29 log10 MPN/gram), and street food (1.79 log10 MPN/gram) had the highest mean log10 E. coli contamination compared to other samples. The contamination concentrations did not differ between low-income and high-income neighborhoods for shared latrine swabs, open drains, municipal water, produce, and street foodsamples. E. coli contamination levels were significantly higher (p <0.05) in low-income neighborhoods compared to high-income for soil (0.91 log10 MPN/gram, 95% CI, 0.39, 1.43), bathing water (0.98 log10 MPN/100 mL, 95% CI, 0.41, 1.54), non-municipal water (0.64 log10 MPN/100 mL, 95% CI, 0.24, 1.04), surface water (1.92 log10 MPN/100 mL, 95% CI, 1.44, 2.40), and floodwater (0.48 log10 MPN/100 mL, 95% CI, 0.03, 0.92) samples. E. coli contamination were significantly higher (p<0.05) in low-income neighborhoods compared to transient/floating neighborhoods for drain water, bathing water, non-municipal water and surface water. Future studies should examine behavior that brings people into contact with the environment and assess the extent of exposure to fecal contamination in the environment through multiple pathways and associated risks.