Enhancing control of schistosomiasis in Niger: assessing morbidity in preschool-aged children, praziquantel treatment efficacy and cost implication for control INAUGURALDISSERTATION zur Erlangung der Würde eines Doktors der Philosophie vorgelegt der Philosophisch-Naturwissenschaftlichen Fakultät der Universität Basel von Amadou Garba Djirmay aus Niamey, Niger Basel, 2013 Genehmigt von der Philosophisch-Naturwissenschaftlichen Fakultät auf Antrag von Prof. Dr. Jürg Utzinger, Dr. David Rollinson Basel, den 20. September 2011 Prof. Dr. Martin Spiess Dekan der Philosophisch- Naturwissenschaftlichen Fakultät Table of contents Table of contents Table of contents .................................................................................................................. i List of tables ........................................................................................................................ v List of figures .................................................................................................................... vii List of abbreviations ........................................................................................................... ix Summary ............................................................................................................................ xi Zusammenfassung ............................................................................................................. xv Résumé ............................................................................................................................. xxi Acknowledgements ........................................................................................................ xxix 1. Introduction ............................................................................................................... 1 1.1. Schistosomiasis: biology and life cycle ............................................................... 1 1.2. Schistosomiasis distribution ................................................................................. 4 1.2.1. Schistosomiasis in the world ......................................................................... 4 1.2.2. Schistosomiasis in Niger ............................................................................... 5 1.3. Morbidity due to schistosomiasis ......................................................................... 6 1.3.1. Urogenital schistosomiasis ............................................................................ 7 1.3.2. Intestinal schistosomiasis .............................................................................. 8 1.4. Diagnostic of schistosomiasis .............................................................................. 9 1.4.1. Clinical diagnostic ........................................................................................ 9 1.4.2. Parasitological diagnostics ............................................................................ 9 1.4.3. Immunological diagnosis ............................................................................ 10 1.4.4. Other diagnostic methods ........................................................................... 10 1.4.5. Community diagnostic ................................................................................ 11 1.5. Schistosomiasis control ...................................................................................... 13 1.5.1. Preventive chemotherapy ............................................................................ 13 1.5.2. The move towards elimination .................................................................... 15 1.6. References .......................................................................................................... 15 2. Goals and objectives ................................................................................................ 33 2.1. Aim of the study ................................................................................................. 33 2.2. Specific objectives .............................................................................................. 33 3. Present and future schistosomiasis control activities with support from the ‘Schistosomiasis Control Initiative’ in West Africa ............................................... 35 3.1. Summary ............................................................................................................... 36 3.2. Introduction ........................................................................................................ 37 3.3. National schistosomiasis control programmes in Burkina Faso, Mali and Niger ............................................................................................................ 38 3.3.1. Distribution of the disease .......................................................................... 38 3.3.2. Objectives, targets and strategies of control programmes .......................... 38 3.4. Mass treatment and its impact ............................................................................ 38 3.5. Maintaining the benefits of mass treatment ....................................................... 43 3.5.1. The continuation of the treatment campaigns ............................................. 43 3.5.2. Villages targeted for control ....................................................................... 44 3.5.3. Additional control strategies ....................................................................... 45 3.5.4. Can we consider transmission control? ....................................................... 45 i Table of contents 3.6. Future: Integration of the programmes and the control of neglected tropical diseases ................................................................................................. 46 3.7. Conclusion .......................................................................................................... 46 3.8. Acknowledgements ............................................................................................ 47 3.9. References .......................................................................................................... 48 4. Schistosomiasis in infants and preschool-aged children: infection in a single Schistosoma haematobium and a mixed S. haematobium-S. mansoni foci of Niger .. 53 4.1. Abstract .............................................................................................................. 54 4.2. Introduction ........................................................................................................ 55 4.3. Materials and methods ....................................................................................... 56 4.3.1. Study area .................................................................................................... 56 4.3.2. Ethical consideration and treatment ............................................................ 57 4.3.3. Questionnaire survey .................................................................................. 58 4.3.4. Parasitological survey ................................................................................. 58 4.3.5. Statistical analysis ....................................................................................... 59 4.4. Results ................................................................................................................ 59 4.4.1. Characteristics of study population ............................................................ 59 4.4.2. Infection with S. haematobium .................................................................. 60 4.4.3. Infection with S. mansoni ........................................................................... 61 4.4.4. Co-infection with S. haematobium and S. mansoni ................................... 62 4.4.5. Risks factors for early childhood schistosome infections .......................... 62 4.5. Discussion .......................................................................................................... 65 4.6. Acknowledgements ............................................................................................. 70 4.7. References ........................................................................................................... 71 5. Efficacy and safety of two closely spaced doses of praziquantel against Schistosoma haematobium and S. mansoni and re-infection patterns in school-aged children in Niger ............................................................................................................. 75 5.1. Abstract ............................................................................................................... 76 5.2. Introduction ......................................................................................................... 77 5.3. Materials and methods ........................................................................................ 79 5.3.1. Study area ..................................................................................................... 79 5.3.2. Study design ................................................................................................. 80 5.3.3. Ethics statement and operational considerations .......................................... 80 5.3.4. Field and laboratory procedures ................................................................... 81 5.3.5. Treatment and monitoring of adverse events ............................................... 82 5.3.6. Statistical analysis