Water, Worms and Weird Diseases: Water Quality Variability and Pediatric Health Outcomes in Northern Coastal Ecuador Open Access

Fanny, Sanemba Aya (2016)

Permanent URL: https://etd.library.emory.edu/concern/etds/wd375w82q?locale=en


Background: poor water quality (WQ) is known to contribute to poor health outcomes such as diarrhea and soil transmitted helminth (STH) infections. However, studies attempting to link WQ and waterborne illnesses often find conflicting results while studies of interventions that aim at reducing water contamination successfully show that improved water quality decreases waterborne illness risk. Experts argue that this contrast can be explained by study design and the variability of microbial indicators.

Purpose: this study intended to: 1) characterize the factors that influence WQ within households (i.e. rural vs urban setting, water source, intermittent water supply, storage, and treatment), 2) determine the association between WQ, diarrhea and STH infections, 3) compare intra- and inter- household WQ variability in order to help guide potential new WQ standards, and inform better study designs.

Methods: a field study was conducted in the district of Quinindé, Ecuador. Survey data and water samples were collected during household visits. WQ was measured using E.coli (EC) and total coliforms (TC) as bacterial indicators. Non-parametric tests, linear and logistic regression were used for data analysis.

Results: River water had the highest contamination but all other sources of water were also contaminated. Rural households that do not have access to improved municipal water sources had significantly higher contamination (EC:1.17 log10 MPN/100 mL , TC: 2.87 log10 MPN/100 mL) than urban households (EC:0.90 log10 MPN/100 mL, TC: 2.49 log10 MPN/100 mL). Boiled water was strongly associated with lower contamination when compared to untreated water (EC: β=-0.73, p<0.0001; TC: β=-0.87, p=0.0002). Storage was a strong predictor for higher contamination (EC: β=0.33, p=0.0014; TC: β=0.62, p<0.0001). For households that used potable water, intermittent water supply was linked with higher rates of storage (OR=2.2, p=0.01). Both diarrhea (OR=1.1, p=0.0475) and STH infections (OR=1.16, p<0.0001) were associated with higher contamination levels. EC was a more accurate microbial indicator than TC. WQ variability was greater within rural households.

Conclusions: WQ measurements and factors that pose a contamination risk such as storage, water source and treatment should be incorporated into new water safety and risk assessment measures for more accurate monitoring of progress made towards universal access to safe water.

Table of Contents

Chapter 1: Introduction 1

Introduction and rationale 1

Problem statement 2

Purpose statement 3

Significance statement 4

Definition of terms 5

Chapter 2: Literature review 7

Burden of disease 7

International efforts around water, hygiene and sanitation 9

MDG target 7c and JMP monitoring 10

Is the mission really accomplished? MDG criticism and skepticism 11

Less than optimal access 13

Household water storage and its effects on water quality 15

Water quality variability and reliability of indicator organisms 18

Does clean water really matter? Evidence supporting efforts for clean water 20

Summary 22

Chapter 3: Materials and methods 24

Introduction 24

Population and sample 24

Research design 26

Procedures 26

Instruments 27

Data Analysis 28

Ethical Considerations 28

Limitations and delimitations 29

Chapter 4: Results 30

Descriptive statistics 30

Factors affecting water quality 33

Geographical location 33

Intermittent water supply 34

Storage 36

Source 37

Treatment 38

Simple linear regression 39

Multiple linear regression 40

Factors leading to water storage 43

Factors predicting diarrhea 44

Water quality and STH infection 44

Intra- versus inter- household water quality variability 45

Water quality measurements variability based on microbial indicator 48

Chapter 5: Discussion 49

Factors affecting water quality 49

Factors predicting water storage 52

Factors predicting diarrhea 53

Factors predicting STH infection 53

Intra- versus inter-household water quality variability 54

Water quality measurements variability based on microbial indicators 54

Limitations and future directions 55

Conclusion 57

Recommendations 57

Literature Cited 60

Appendix A: Questionnaire form for surveys 64

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