Quantifying Urban Sanitation Coverage and its Association with Fecal Contamination in Open Drain Systems in Accra, Ghana Öffentlichkeit

Abstract

Introduction: Poor sanitation coverage is a common issue in most low and middle income countries around the world today and is often associated with higher levels of fecal contamination in the environment. This study aims to analyze whether associations exist between sanitation coverage at the household level and fecal contamination in open drain systems in Accra, Ghana.

Methods: Household surveys (n = 750) and drain water samples (n = 163) were collected in 5 neighborhoods of Accra. Kulldorff's Bernoulli spatial scans were used to identify most-likely clusters of surveyed household sanitation characteristics (level of toilet containment, shared vs. unshared toilet, and frequency of public toilet use). Toilet containment refers to the safe disposal and physical separation of excreta from human contact. E. coli concentrations were quantified in drain water samples and regressed against sanitation characteristics, controlling for neighborhood, drain infrastructure, and rainfall.

Results: Compared to all other study neighborhoods, Ringway -- the neighborhood with the highest coverage of private sanitation use (vs. public sanitation use) -- had significantly lower E. coli concentrations in drain samples. Drain sample sites within 50 meters of clusters of high coverage of contained sanitation had, on average, 1.08 log10CFU/100mL lower E. coli concentrations than drains located outside of these clustered areas (p=0.003). Drains within 100 meters of clusters of low coverage of households that did not use public toilets had, on average, 1.19 log10CFU/100mL higher E. coli concentrations than all other drains located outside of these clustered areas (p=0.007).

Discussion: The results from this study provide some of the first evidence suggesting that clustering of contained sanitation and private toilet use, as opposed to public toilet use, may be associated with lower levels of fecal contamination in open drain systems, and conceivably the remaining proximal environment.

Table of Contents

I. Background/Literature Review...........................................................................1

A. Setting Up the Context................................................................................. 1

i. Diarrheal Disease............................................................................. 1

ii. WASH & Diarrheal Disease............................................................ 2

iii. Sanitation in Low- and Middle-Income Countries (LMICs)............ 4

iv. Diarrheal Disease & Sanitation in Context to Africa........................ 4

v. Urbanization & Sanitation................................................................ 5

vi. Urbanization and Sanitation Coverage in Accra............................... 6

B. Fecal Sludge Management (FSM)............................................................... 8

i. Fecal Waste Management & the Sustainable Development Goals (SGDs)....8

ii. FSM & Open Drain Systems........................................................... 9

C. Evaluation of Fecal Contamination............................................................. 11

i. Fecal Indicator Organisms............................................................. 11

ii. E. coli as a Contaminant................................................................. 11

D. Fecal Contamination Exposure Pathways.................................................. 12

i. Fecal-Oral Transmission Pathway................................................. 12

ii. Uncontained Toilets as an Environmental Exposure...................... 13

iii. Shared Sanitation as an Environmental Exposure.......................... 14

iv. Fecal Exposure Through Open Drain Systems in Accra................ 16

E. Impacts of Understanding Fecal Exposure Pathways................................ 17

II. Manuscript.................................................................................................. 19

A. Abstract...................................................................................................... 19

B. Introduction................................................................................................ 20

C. Methods..................................................................................................... 24

i. Study Area..................................................................................... 24

ii. Household Surveys........................................................................ 25

iii. Drain Sample Collection................................................................ 26

iv. Sanitation Coverage Quantification................................................ 27

v. Regression Modeling..................................................................... 29

vi. Assumptions.................................................................................. 30

vii. Analysis......................................................................................... 30

D. Results....................................................................................................... 32

i. Household Demographics & Environmental Characteristics.......... 32

ii. Spatial Sanitation Cluster Coverage............................................... 34

iii. Variation in E. coli Concentration in Drain Water by Neighborhood,

Drain Infrastructure, & Rainfall........................................................ 35

iv. Variation in E. coli Contamination in Drain Water......................... 36

E. Discussion................................................................................................. 38

F. Strengths/Limitations................................................................................. 44

G. References.................................................................................................. 47

H. Tables..................................................................................................... 62

I. Figures....................................................................................................... 69

J. Glossary..................................................................................................... 73

III. Future Directions...................................................................................... 75

IV. Appendix.................................................................................................. 76

A. IRB Approval............................................................................................ 76

B. Household Survey..................................................................................... 78

C. Drain Water: Environmental Drain Water and Processing Form................ 82

About this Master's Thesis

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• Permission granted by the author to include this thesis or dissertation in this repository. All rights reserved by the author. Please contact the author for information regarding the reproduction and use of this thesis or dissertation.

School	Rollins School of Public Health
Department	Epidemiology
Subfield / Discipline	Global Epidemiology - MPH & MSPH
Degree	MPH
Submission	Master's Thesis
Language	English
Research Field	Health Sciences, Public Health Environmental Health Health Sciences, Epidemiology
Stichwort	Sanitation coverage Urban sanitation Accra Fecal contamination E. coli Open drains
Committee Chair / Thesis Advisor	Kirby, Amy, Emory University
Committee Members	Berendes, David, Georgia Institute of Technology, School of Civil and Environmental Engineering
Partnering Agencies	University, college or educational institution (other than Emory)

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