Exploring strategies and approaches to schistosomiasis control and elimination - the role of basic and applied research

Bc. Enoch Mensah Boateng

Doctoral thesis

Abstract:

Schistosomiasis continues to exert debilitating effects and public health threat to over 240 million people with about 700 million people at risk of infection. The health and economic implications of this neglected tropical disease are devastating hence there is a need for the adoption of effective control and elimination strategies by endemic countries. However, a significant gap exists between schistosomiasis researchers and control program implementers. The thesis includes four studies: a literature review of the schistosomiasis situation in Ghana, two field-based studies of praziquantel mass drug administration efficacy using an alternative approach of xenomonitoring of snail intermediate hosts, as well as direct evaluation with human samples, and finally, an experimental study on SmM28B (S. mansoni ortholog of human glutamate carboxypeptidase II) and its role in the development and survival of the parasite. The thesis comprises an introduction that provides a foundation and aims for the studies, a literature review of the existing corpus of knowledge as well as knowledge gaps in the control of schistosomiasis, the above-mentioned four independent studies each addressing a particular aim, and an overall summary (general discussion with concluding remarks). The studies included in this thesis present insightful findings that are useful for schistosomiasis control. Numerous research and knowledge gaps have been identified in Ghana as a schistosomiasis endemic region, followed by suggestions for future actions to bridge these gaps to reach recent WHO targets and eliminate schistosomiasis as a public health problem. Xenomonitoring as one of the proposed approaches has been evaluated in Ghana for the first time and indicated a limited effect of praziquantel mass drug administration on schistosomiasis transmission in areas under study. Also, the short-term effectiveness of PZQ MDA was evaluated via immunological and parasitological methods. Among other findings, these three studies confirm the urgent need for alternative drugs and/or vaccine candidates. The investigation of S. mansoni M28B peptidase provided first-hand information about the expression and localization of SmM28B in the reproductive and digestive tissues/organs across all developmental stages of Schistosoma mansoni and identified its biological functions which set the stage for further translational studies.

Keywords

Schistosomiasis, Control, Mass Drug Administration, Monitoring, Evaluation, Xenomonitoring, Proteases, Schistosoma mansoni

Language used: English

Date on which the thesis was submitted / produced: 19. 9. 2024

Thesis defence

• Supervisor: RNDr. Jan Dvořák, Ph.D.
• Reader: Martin Horn, externi, Libor Mikeš, externi, Petra Matoušková, externi

Czech University of Life Sciences Prague

Faculty of Agrobiology, Food and Natural Resources

Doctoral programme:
Applied Zoology