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Human and Animal Schistosomiasis and Fascioliasis in a Mobile Pastoralist Setting at Lake Chad: a One Health Approach

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Human and Animal Schistosomiasis and Fascioliasis in a Mobile Pastoralist Setting at Lake Chad: a One Health Approach Human and animal schistosomiasis and fascioliasis in a mobile pastoralist setting at Lake Chad: A One Health approach INAUGURALDISSERTATION zur Erlangung der Würde eines Doktors der Philosophie vorgelegt der Philosophisch-Naturwissenschaftlichen Fakultät der Universität Basel von Helena Pia Greter aus Luzern (LU) Basel, 2018 Originaldokument gespeichert auf dem Dokumentenserver der Universität Basel edoc.unibas.ch Genehmigt von der Philosophisch-Naturwissenschaftlichen Fakultät auf Antrag von Prof. Dr. Jakob Zinsstag und Prof. Dr. Robert Bergquist. Basel, 23. Februar 2016 Prof. Dr. Jörg Schibler Dekan For the people of Lake Chad Table of contents Table of contents ...................................................................................................................................... I List of Figures .......................................................................................................................................... III List of Tables ........................................................................................................................................... VI List of Abbreviations ............................................................................................................................. VIII Acknowledgements ................................................................................................................................ IX Summary .............................................................................................................................................. XIII Résumé ................................................................................................................................................. XVI 1. Introduction ................................................................................................................................. 1 1.1. Neglected parasite infections in humans and animals ............................................................ 1 1.2. Trematode biology .................................................................................................................. 2 1.3. Human and animal trematode infections: burden, diagnosis and treatment ........................ 4 1.4. Study area: Chad and Lake Chad ............................................................................................. 9 1.5. Mobile pastoralism at Lake Chad .......................................................................................... 12 1.6. Human and animal health in Chad ........................................................................................ 14 1.7. Underlying concepts of this research project ....................................................................... 15 1.8. Identified research gaps, aims and objectives ...................................................................... 20 1.9. Field activities: planned procedures and unforeseen challenges ......................................... 22 1.10. Collaborating Partners ....................................................................................................... 23 2. Outline of Thesis ........................................................................................................................ 24 3. The benefits of ‘One Health’ for pastoralists in Africa .............................................................. 25 4. Human and animal health surveys among pastoralists ............................................................ 31 5. Prevalence of Fasciola gigantica infection in slaughtered animals in south-eastern Lake Chad area in relation to husbandry practices and seasonal water levels ...................................................... 42 6. Human and animal trematode infections in a mobile pastoralist setting at Lake Chad: added value of a One Health approach beyond zoonotic diseases research .................................................. 54 7. Treatment of human and livestock helminth infections in a mobile pastoralist setting at Lake Chad: Attitudes to health and analysis of active pharmaceutical ingredients of locally available anthelminthic drugs .............................................................................................................................. 66 I 8. Rapid re-infection with Fasciola gigantica in cattle 6 months after triclabendazole treatment in a mobile pastoralist setting at Lake Chad ......................................................................................... 83 9. Validation of a point-of-care circulating cathodic antigen urine cassette test for Schistosoma mansoni diagnosis in the Sahel, and potential cross-reaction in pregnancy ........................................ 95 10. All that is blood is not schistosomiasis: experiences with reagent strip testing for urogenital schistosomiasis with special consideration to very-low prevalence settings ..................................... 102 11. The spatial and seasonal distribution of Bulinus truncatus, Bulinus forskalii and Biomphalaria pfeifferi, the intermediate host snails of schistosomiasis, in N’Djamena, Chad ................................. 118 12. Discussion and conclusions ..................................................................................................... 133 References ........................................................................................................................................... 147 Appendix 1: The mobile pastoralists of Lake Chad .................................................................................. i Appendix 2: Impressions from the bench and the field ........................................................................... v Appendix 3: IOHC Poster Award ............................................................................................................. vii Appendix 4: Report in the SNSF Magazine HORIZONS, 2014, No 101, p. 29-31 ................................... viii II List of Figures Figure 1.1. The life cycle of the human blood flukes, illustrated here for Schistosoma haematobium and S. mansoni , is comparable to the life cycle of S. bovis, which infects ruminants . ........................... 2 Figure 1.2. Adult Schistosoma flukes, here S. bovis in slaughtered cattle , live in the mesenteric veins (left). The spindle-shaped egg of S. bovis has a characteristic terminal spine (right). (Photos: A. A. Batil, H. Greter)........................................................................................................................................ 3 Figure 1.3. Life cycle of Fasciola gigantica . (Photos: W. Moser, fileshare.org, H. Greter) ..................... 4 Figure 1.4. Global distribution of Schistosoma species causing human schistosomiasis. (Colley, D. G. et al. (2014). The Lancet) ............................................................................................................................. 5 Figure 1.5. World map highlighting countries where schistosomiasis has been eliminated (green color), is close to elimination (yellow color) or where national control programs or some preventive chemotherapy are in place (orange color). Marked in red are countries where schistosomiasis is endemic and national control programs are not yet implemented (Rollinson, 2013). .......................... 6 Figure 1.6. Global distribution of Schistosoma species which affect livestock (Over et al. 1992). ......... 7 Figure 1.7. Distribution of Fasciola gigantica and F. hepatica in Africa (adapted, Over et al. 1992). .... 8 Figure 1.8. Distribution of human fascioliasis worldwide, latest year available (WHO, 2015). .............. 9 Figure 1.9. Chad is situated in central Africa. The red circle indicates the study area on the eastern shore of Lake Chad. ............................................................................................................................... 10 Figure 1.10. Map showing Lake Chad at its largest surface area (grey, 1972) and at its smallest size (light blue, 1987). During the last decades, the lake seems to be slowly increasing in size. ................ 11 Figure 1.11. Moving patters over one year of Fulani (blue), Arab (green) and Gorane (red) mobile pastoralists at the south-eastern shores of Lake Chad. The size of the dot indicates the duration of the stay at one specific site. By comparing the three movement patterns, clearly distinct land usage patterns can be seen for the three ethnic groups (Jean-Richard et al. 2014f). .................................... 14 Figure 1.12. Scheme showing the planned research at the human-animal-environment levels within the One Health approach. The project includes a Chadian and a Swiss MSc thesis as well as the PhD thesis presented here. ........................................................................................................................... 17 Figure 1.13. Synopsis of the dynamic processes involved in human and animal schistosomiasis and fascioliasis transmission in the social-ecological system in the study area on the eastern shores of Lake Chad. These basic data will allow for development of a mathematical transmission model....... 18 Figure 1.14. Stakeholder meeting at the start of the project, which took place in N’Djamena, 15.-16. March 2013. (Photo: W. Moser)............................................................................................................ 20 Figure 5.1. Fasciola gigantica from a cow in the south-eastern Lake Chad area.................................. 45 Figure
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