Operational Implications of Trachomatous Trichiasis Prevalence Estimation and Pilot Guide for Assessing Trachomatous Trichiasis in Low Burden Areas Open Access

Plunkett, Elizabeth (2017)

Permanent URL: https://etd.library.emory.edu/concern/etds/bz60cx11w?locale=en


Introduction: Trachoma is the leading infectious cause of preventable blindness. To reach the goals of the Global Elimination of Trachoma by the year 2020 (GET 2020) initiative, global partnerships are implementing trachoma elimination activities in Mozambique and across the globe.

Objective: The purpose of this research is to investigate the operational implications of recalculating prevalence estimates of trachomatous trichiasis (TT); this study examined expected cases and surgical backlog estimates using population figures from various sources to provide information on methods related to calculating these figures. Critically analyzing the survey methods and figures used to calculate TT surgery backlog will allow a better assessment of methods and progress towards identifying and managing unknown TT cases. This research also aims investigate the process of implementation for a pilot guide for assessing trichiasis cases in low burden areas in Mozambique. This analysis, as well as approaches to case finding in Mozambique, will contribute towards the development of new methods for evaluating trachoma elimination activities and provide guidance to other countries faced with similar challenges in TT case finding and management activities.

Methods: Baseline prevalence surveys from three districts of Mozambique were analyzed to estimate TT prevalence at the enumeration unit (EU) and cluster level, and to estimate the expected TT surgical backlog. In depth interviews with key informants were conducted to document the implementation of a pilot guide for identifying TT cases.

Results: TT prevalence estimates calculated in this analysis using 2013 census data for weighting were much higher than those calculated in the original analysis. EU-level adjusted TT prevalence ranged from 1.25% (95% CI: 0.66, 2.37) in Namuno, to 1.35% (95% CI: 0.82, 2.23) in Balama, and 1.45% (95% CI: 0.87, 2.67) in Montepuez. Cluster level average TT prevalence ranged from 1.20% in Namuno, to 1.33% in Balama, and 1.59% in Montepuez. This increase in prevalence estimate calculations resulted in subsequent increases in TT surgical backlog estimates. The pilot guide for identifying TT cases in low burden areas was successfully piloted in all three districts and reflection on the implementation process yielded numerous suggestions for strengthening the guide before implementation in further districts.

Recommendations: As Mozambique moves toward elimination of trachoma as a public health problem and transitions trachoma program activities solely to the health system, clear and transparent methods for data analysis should be created and standardized to allow national program staff to support elimination objectives. This research and the pilot guide can serve as tools to support completion and submission of the WHO dossier for certification of elimination of trachoma as a public health program.

Table of Contents

Table of Contents

1. Introduction 1

1.1 Problem statement 1

1.2 Purpose statement 2

1.3 Research Goals 2

1.4 Significance statement 3

1.5 Definition of terms 3

2. Literature Review 5

2.1 Global Burden of Trachoma 5

2.1.1 Clinical description and epidemiology 5

2.1.2 Global Distribution and Morbidity 6

2.2 History of Trachoma Elimination 7

2.2.1 SAFE Strategy 8

2.2.2 Validation of elimination as a public health problem 10

2.3 Elimination Activities and Trachomatous Trichiasis 10

2.3.1 Survey Methodology 11

2.3.2 Recently Published Studies Measuring Country-specific Trachoma Disease Burden 12

2.3.5 TT elimination activities in areas with limited disease 15

2.4 Trachoma Elimination Activities in Mozambique 18

2.5 Summary of Problem and Relevance 21

3. Methods 22

3.1 Research Design 23

3.2 Population and Sample 26

3.3 Study Procedures 27

3.4 Plans for data analysis 30

3.5 Ethical Considerations 31

3.6 Limitations 31

4. Results 31

4.1 Trachoma Prevalence Survey Results 32

4.2 TT Surgery Backlog Estimates 37

4.3 Limitations 40

4.4 Pilot Guide Implementation 40

4.5 Summary 42

5. Discussion 43

5.1 TT Prevalence Estimates, Expected Cases and Surgical Backlog 43

5.2 Pilot Guide Implementation 46

5.2.1 Challenges and Successes 46

5.2.1 Guide Strengthening 49

6. Implications and Recommendations 50

References 53

Appendices 55

Appendix A. Template for the dossier documenting elimination of trachoma as a public health problem 55

Appendix B. Approaches for identifying trichiasis cases in low burden areas: Methods for evaluating trichiasis backlog and achieving elimination targets in 3 districts of Mozambique: Balama, Montepuez, and Namuno 62

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