Cultural, social and economic influences on ongoing S. mansoni transmission and the potential for change

MRC Global Challenges Research Fund (GCRF) Foundation Award
PI: Poppy Lamberton

Over 240 million people are infected with schistosomiasis in lower and middle income countries (LMICs), of whom over 90% are in sub-Saharan Africa (SSA). Schistosomiasis is second only to malaria among parasitic diseases in its socio-economic and public-health importance. Transmission is linked to poverty, driven by poor water, sanitation and hygiene (WASH) conditions. The disease causes severe long-term morbidity, and reduces physical and cognitive development, exacerbating the poverty cycle. The World Health Organization (WHO) recommends >75% of school-aged children be regularly treated with praziquantel to prevent morbidity and ultimately eliminate the disease as a public health problem. However continual reinfection and transmission occur, even after treatment. Infection hotspots which are not reducing are reported. In Uganda, we have observed mean infection intensities that are now higher after a decade of mass drug administration (MDA) than at baseline. MDA and school-based interventions alone will not reduce these hotspots. Broader, more integrated, ‘biosocial’ approaches are needed to control disease.

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Our project aims identify ‘best bets’ across possible combinations of interventions to reduce Schistosoma mansoni transmission and exposure over the long term. These best bets will be partly based on a series of potential infrastructural investments (e.g. washing stations, locally managed pit latrines and/or provision of safe bathing water) and partly on a quantification of behavioural factors which facilitate such investments being taken up and used. The best bets will be sensitive to differences in socio-economic status and, crucially, will take account of the need to ensure that existing practices are reduced or altered in a way which effectively reduce transmission and exposure.

Our University of Glasgow team includes Lucy Pickering and Sally Wyke from the Institute of Health and Well Being, College of Social Sciences and Poppy Lamberton and Nick Hanley from the Institute of Biodiversity, Animal Health and Comparative Medicine, College of Medicine, Veterinary and Life Sciences. We are working in close collaboration with Janet Seeley at the MRC Ugandan Research Institute, Uganda and Edridah Tukahebwa at the Vector Control Division, Ministry of Health, Uganda, with Agnes Ssali, Edith Nalwadda, and Lazaro Mujumbusi employed as anthropologists on the project.

Our aim is to provide a strong, locally-informed, behaviourally-consistent foundation for the design and feasibility of complex interventions to reduce transmission of this debilitating disease. We are building on existing knowledge to understand how people living in endemic areas manage their risk of S. mansoni infection and transmission (Work Package 1 (WP1)) and how they might change their behaviour if additional resources were provided (WP2). We are using rapid ethnographic appraisals (REAs), focus groups, participation, observations etc combined with stated-preference choice models to understand how people might change their behaviour. Keila Meginnis is using these data to build behaviour choice experiments to test our qualitative results in a quantitative manner. Results will lead to further grant applications for intervention trials and implementation of a new, more effective strategy to address this vital health challenge in Africa.

A University of Glasgow Lord Kelvin Adam Smith PhD student Suzan Trienekens, works on an interdisciplinary project that overlaps between this MRC GCRF anthropology and economics project with the ERC SCHISTO_PERSIST project. Suzan is using rapid ethnographic appraisals and other field sociology techniques to understand where children who are either not infected, or who are rapidly reinfected post treatment contact the water. Suzan will then collect snails from these areas and shed them for S. mansoni cercariae. She will compare the genotypes of these cercariae to miracidia characterised in SCHISTO_PERSIST to understand which parts of the community are driving reinfection in these water bodies.