CID: 00636012 Mapping of Schistosomiasis and Soil- transmitted helminths in Yemen, and the push for elimination CID: 00636012 Master of Public Health (General) MPH Date: 31st August 2014 Word Count: 10,852 words Page 1 of 116 CID: 00636012 Acknowledgements First of all, I would like to thank my supervisors for their support and advice throughout the duration of this project. Their patience, constructive feedback and suggestions provided during the planning and development of this work has been very much appreciated. I am grateful for their invaluable guidance on report writing and on the analysis of data with the statistical and mapping software. Special thanks to the lecturers and staff under the Imperial College London School of Public Health for their teachings and constant help over the course of the MPH programme. I am also most grateful to my family, friends and fellow students under the MPH programme for their support and encouragement during the preparation of this project. Finally, I would like to extend my thanks to the prevalence mapping teams, supervisors and programme managers under the National Schistosomiasis Control Programme, Sana’a University and the Ministry of Public Health and Population in Yemen for their hard work and dedication in the planning, implementation and monitoring of the data collection survey, and without whom this project would not have been possible. Page 2 of 116 CID: 00636012 Table of Contents Acknowledgements .............................................................................................................. 2 Table of Contents ................................................................................................................ 3 List of Tables ....................................................................................................................... 5 List of Figures ...................................................................................................................... 6 List of Abbreviations ............................................................................................................ 7 Abstract ................................................................................................................................ 9 1 Introduction ..................................................................................................................... 11 1.1 Schistosomiasis ........................................................................................................ 11 1.2 The Schistosomiasis Control Initiative ...................................................................... 13 1.3 Yemen National Schistosomiasis Control Programme ............................................. 15 1.4 Prevalence Mapping ................................................................................................. 17 1.4.1 Introduction to Mapping ...................................................................................... 17 1.4.2 Baseline Prevalence Mapping ............................................................................ 17 1.4.3 Prevalence Re-mapping ..................................................................................... 20 2 Methods .......................................................................................................................... 22 2.1 Prevalence Re-mapping survey ................................................................................ 22 2.1.1 Mapping strategy ................................................................................................ 22 2.1.2 Survey methods ................................................................................................. 25 2.1.3 Ethical considerations ........................................................................................ 28 2.2 Data analysis ............................................................................................................ 28 3 Results ............................................................................................................................ 30 3.1 Re-mapping Survey .................................................................................................. 30 3.2 Prevalence ................................................................................................................ 31 3.2.1 Schistosomiasis .................................................................................................. 31 3.2.2 Soil-transmitted helminths .................................................................................. 34 Page 3 of 116 CID: 00636012 3.2.3 Anaemia ............................................................................................................. 37 4 Discussion ...................................................................................................................... 41 4.1 Limitations and recommendations for improvement ................................................. 48 4.2 The road to elimination ............................................................................................. 50 5 Conclusions .................................................................................................................... 55 6 References ..................................................................................................................... 56 7 Appendices ..................................................................................................................... 60 Appendix 1: Recommended dose-pole for the mass drug administration of praziquantel for treatment of schistosomiasis ..................................................................................... 60 Appendix 2: Targeted districts and dates on which teams started the re-mapping survey in Yemen ........................................................................................................................ 61 Appendix 3: Suggested Data Collection (paper case report) forms ............................... 62 Appendix 4: Yemen prevalence re-mapping team members and responsibilities .......... 65 Appendix 5: Prevalence re-mapping supervisory field visit evaluation form ................... 66 Appendix 6: Planned and actual total numbers sampled by each team at the end of the prevalence re-mapping survey in Yemen ....................................................................... 70 Appendix 7: Map of the population distribution of Yemen ............................................... 71 Appendix 8: Prevalence of schistosomiasis, soil-transmitted helminths and anaemia in Yemen ............................................................................................................................ 72 Table of the prevalence of schistosomiasis, soil-transmitted helminths and anaemia by governorate in Yemen (2014) ...................................................................................... 72 Table of the prevalence of schistosomiasis by district in Yemen (2014) ..................... 73 Table of the prevalence of soil-transmitted helminths by district in Yemen (2014) ...... 85 Table of the prevalence of anaemia by district in Yemen (2014) ................................. 97 Classification of 332 districts by level of severity of the prevalence of severe anaemia in Yemen ................................................................................................................... 109 Appendix 9: Prevalence maps of disease distribution in Yemen .................................. 110 Appendix 10: Maps of distribution of water bodies in Yemen ....................................... 116 Page 4 of 116 CID: 00636012 List of Tables Table 1: Type, species and global distribution of SCH ...................................................... 11 Table 2: Classification of districts and corresponding treatment approach for schistosomiasis at school and community level in Yemen ................................................. 20 Table 3: Classification of districts according to risk category for schistosomiasis in Yemen ........................................................................................................................................... 23 Table 4: Classification of districts according to risk category for STHs in Yemen following WHO recommendations ..................................................................................................... 23 Table 5: Classification of anaemia severity at sea level based on measured haemoglobin concentrations by age group .............................................................................................. 24 Table 6: Adjustments to measured haemoglobin concentrations according to altitude in metres above sea level ...................................................................................................... 24 Table 7: Public health significance of anaemia by WHO recommended categories and corresponding prevalence ranges ...................................................................................... 25 Table 8 : Classification of 332 sampled districts by risk category for schistosomiasis infection in Yemen ............................................................................................................. 31 Table 9: Classification of 332 sampled districts by risk category for S. mansoni and S. haematobium infection in Yemen ....................................................................................... 33 Table 10 : Average prevalence of Ascaris infection in four governorates