Cultural, social and economic influences on ongoing Schistosoma mansoni transmission, despite a decade of mass treatment, and the potential for change

Lead Research Organisation: University of Glasgow
Department Name: College of Medical, Veterinary, Life Sci


Schistosomiasis, commonly known as Bilharzia, is a parasitic disease which infects over 240 million people worldwide. Over 90% of these people live in poor rural communities in sub-Saharan Africa. The disease causes anaemia, abdominal pain, stunted growth and reduced cognitive development in children, and up to 200,000 deaths per year. Over 600 million people live in areas where they are at risk of infection. The eggs of the parasite Schistosoma mansoni, are excreted in human stool, hatch in fresh water and infect snails, where they reproduce asexually to produce 1000s of larvae (called cercariae) per day. These cercariae infect humans by directly burrowing through the skin, and developing into adult worms. The life-cycle is maintained by open defecation, or inadequate containment of human faeces, enabling eggs to reach fresh water sources, followed by contact with infected water through activities such as bathing, swimming, washing clothes or fishing.

Current control focuses on drug treatments given annually on a national scale to school children. However, despite over a decade of national control programmes in countries such as Uganda, high infection levels persist in hotspot areas. Drug treatment alone will not reduce the disease in these areas and additional interventions are needed. It is known that improved sanitation and access to clean safe water supplies can stop people from getting infected. However, many areas with the disease lack money and resources to improve sanitation and furthermore, when sanitation is improved, it is not always used. We do not fully understand what makes people alter water and sanitation focused behaviours even in the presence of good facilities.

Therefore, the project aims to understand better how people living in endemic communities manage their risk of schistosomiasis and how they might change their behaviour if additional resources were provided.

This project has two overlapping parts. In part one, we will work directly with communities who experience a lot of schistosomiasis to establish how people currently try to reduce the risk of infection for themselves and their families as well as the risk of passing those infections on through open defecation. We will work in three villages in Uganda using social science methods to observe people going about their everyday life. We will interview them in groups and individually about their understanding of the disease, its effects, how they get infected and their current and desired strategies for reducing infections in the whole community. These data will be used to build up a picture of high and low risk practices and perceptions of disease risk, and how practices and perceptions vary by gender, age, occupation and other factors.

In the second part, this information will be incorporated into household surveys to measure what is needed to change an individual's behaviour. Our methodologies allow us to quantify the ways in which people currently respond to the risks posed by schistosomiasis, and how they might respond if investments in washing, sanitation and hygiene resources in their communities were made. We will also use these models to show how human behaviour is influenced by an understanding of the lifecycle of the parasite, and by knowledge of other people's behaviour.

Our findings will help us identify "best bets" for investments likely to reduce transmission and re-infection which are likely to work in the long-term. Results will inform future research studies, where these interventions are tried out at village and regional levels. Together the programme of work we plan will inform us on how best to control and potentially eliminate bilharzia in given areas, helping to improve the health of children in infected communities.

Technical Summary

Over 240 million people are infected with schistosomiasis, which causes severe morbidity and reduces physical and cognitive development. Despite over a decade of mass drug administration (MDA) to reduce morbidity and aid disease elimination, hotspots of Schistosoma mansoni infections remain. MDA alone will not reduce transmission; additional interventions are required. S. mansoni transmission is linked to poor Water, Sanitation and Hygiene (WASH) conditions with parasite eggs excreted in human stool. This project aims to better understand how people living in endemic communities manage their risk of S. mansoni and how they might change their behaviour if additional resources were provided.

The work is divided into two work packages. WP1 will use rapid ethnographic appraisal to understand how people talk about S. mansoni and respond to on-going interventions such as MDA and WASH resources, how people's behaviour contributes to transmission and re-infection, and the social, economic and cultural barriers that prevent change. WP1 will provide data to WP2, which will estimate an averting behaviour model for risk reduction using count-data modelling. Our model will identify the associations between (i) household and individual characteristics (ii) attitudes to and knowledge of risks and (iii) the availability of local WASH resources with the extent to which measures to reduce their own and others' risks are taken. Next, a stated preference choice experiment will estimate the probability of take up and use of new WASH resources which could be provided (e.g. pit latrines, wash stations), as a function of both the characteristics of the intervention (e.g. cost, maintenance, location) and the characteristics of respondents.

Insights gained from WP1 and WP2 together will provide new, integrated, understanding of best-bet strategies for interventions to reduce the incidence and persistence of this debilitating disease, whilst building social science capacity in Uganda.

Planned Impact

Despite mass drug administration (MDA) schistosomiasis remains a major public health issue with over 240 million people infected in LMICs. Our research is driven by a desire to deliver impact in affected communities. The data it will generate will build a foundation for major advances in strategies to reduce transmission and re-infection rates, and will thus deliver benefits to a range of communities as explained below.

Domain 1 (D1): local residents in case-study villages: The major long-term impact of this work will be felt in Uganda and other LMICs where schistosomiasis is endemic. In the short term we will improve disease understanding and current MDA uptake in study villages. In the medium-term we will potentially reduce individual exposure/transmission levels where WASH choices already exist and, with research-informed investment, where they do not currently exist. Long term improved interventions will reduce transmission, enhancing health in Uganda and other LMICs. Any improvement in sanitation behaviours will also reduce soil-transmitted helminth, intestinal bacteria and viruses, and trachoma transmission.

D2: health policy community in Uganda: Co-I EMT MoH is directly involved in the programme management of schistosomiasis and soil-transmitted helminthiasis; findings can rapidly impact how national control teams discuss interventions with policy makers, including the Ministry of Education, as well as endemic communities. In the medium-term data will provide the basis for transmission and feasibility studies surrounding different interventions within Uganda. In the long term findings may improve the effectiveness of Uganda's public health control programmes and policy, by informing on how best to address improved WASH infrastructure with limited financing.

D3: international Neglected Tropical Diseases (NTDs) health policy community: Data generated in Uganda will be of interest to other endemic countries, including our Planned Partnership with Ghanaian researchers and policy makers (See Pathways to Impact). NGOs working in Uganda and other LMICs such as Sightsavers and World Vision aim to improve WASH facilities and practices and will be directly interested in our findings. With the active engagement in the discussions at the Workshop of Programme Managers from across SSA countries, potential impacts may start to reach other control programmes as well as being of interest to global policy makers and research funders.

D4: research capacity in Uganda: The project will strengthen scientific and economic collaborations between Uganda and the UK. We will build long-lasting relationships, facilitate bilateral knowledge exchange and allow early and mid-career UK-based researchers the opportunity to experience the value of working in a developing country. MoH technicians and MRC/UVRI RAs will develop multidiscipline transferable skillsets and will participate fully in analysis and publications. They will rapidly gain an increased network which can lead to new collaborations and subsequent research fellowships, projects, skills and knowledge.

D5: the international academic community: The Coalition for Operational Research for NTDs, the Global Schistosomiasis Alliance and WASH communities will be interested and influenced by our data. (see Academic Beneficiaries)

D6: media outlets in the UK: Given the £25 million pledged by DfID to control schistosomiasis and the accessibility of infectious disease understanding and compassion, members of the public in the UK and Uganda will be interested in our findings. (see Communications Plan)

Given the issues associated with maintained high infections, the time is ripe for a novel approach to better understand disease control, and for translating these findings into intervention programmes. Our research outputs can be capitalised upon by national and international public health policy makers aiming at improving human health in resource-poor settings.


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Clark J (2022) Reconciling Egg- and Antigen-Based Estimates of Schistosoma mansoni Clearance and Reinfection: A Modeling Study. in Clinical infectious diseases : an official publication of the Infectious Diseases Society of America

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Faust CL (2020) Schistosomiasis Control: Leave No Age Group Behind. in Trends in parasitology

Description Schistosomiasis affects over 240 million people globally, the majority in sub-Saharan Africa. In Uganda, high infection rates exist in communities on the shores of Lake Victoria. Mass drug administration delivered by village health teams is the mainstay of schistosomiasis control in these communities. However, treatment uptake remains suboptimal and people are often rapidly reinfected post-treatment. We investigated the sources of schistosomiasis information in three lake shore communities and how messages are passed on and perceived by community members as well as people's perceptions of schistosomiasis disease, symptoms, transmission and control. We also wanted to know how people living in three endemic communities in Mayuge District-Uganda manage their risk of schistosomiasis infection and how they might change their behaviour if additional resources were provided.

A rapid ethnographic appraisal that included transect walks, observations, individual and group discussions were the methods of data collection. Data was analysed thematically using iterative categorisation. Data was collected from Sept 2017-March 2018 in three lake shore communities in Mayuge district, Eastern Uganda. Discrete choice experiments were then undertaken, designed using the data from the rapid ethnographic appraisals to gain a quantitative understanding of people's qualitative preferences for waster and sanitation based interventions and how much they would be willing to work or willing to pay for each of these different interventions.

1. We found that the main sources of schistosomiasis information included health workers at government facilities, village health teams and radio programmes produced by the Ministry of Health.
2. These messages described the signs and symptoms of the disease, but did not attend to the side effects of praziquantel use.
3. Despite these interventions, we found that the main cause and transmission link was unclear to most participants and that translation of schistosomiasis into the term local language 'ekidada' increased, rather than reduced, confusion about the cause(s) of schistosomiasis.

Understanding of the disease, symptoms and transmission:
1. There is some awareness of schistosomiasis, But knowledge is uneven and often confused.
2. The main cause and transmission link was unclear
3. Messages described the signs and symptoms of the disease. But confusion exists with symptoms of other NTDs such as elephantiasis, trachoma and hookworm.
4. Extended stomachs and thinness were correctly identified as schistosomiasis symptoms, but these were also identified as symptoms of other conditions.
5. Earlier presenting symptoms such as lethargy, diarrhoea and abdominal pain were not understood to be schistosomiasis.

Current ways people reduce their infection risks:
1. The primary, no-cost preventative measure was minimising water contact but observations revealed this did not occur.
2. Other measures such as buying water from safe sources, boiling or filtering it, and leaving it in the sun were considered excessively costly in temporal and financial terms to be practical.
3. Not everyone had access to a private latrine, and many participants stated they did not use public latrines because they were too expensive, too dirty, or too far away when they needed them.
4. Open defecation was common and this was explained mainly in terms of tribal and occupational, culture, or lack of morals, rather than in terms of latrine access.

Preferences for interventions:
Risk to self interventions in order of most popular to least popular:
Tap 10 jerry cans
Lake filtration- potable
Tap 2 jerry cans
Sensitise: VHT talks
Sensitise: Public radio
Sensitise: Murals
Each new landing sites
Lake filtration- non-potable

Risk to self interventions in order of most popular to least popular:
Fines introduced for open defecation anywhere
Fines introduced for open defecation within 30 metres from lake
New latrines built at: 5min from home
New latrines built at: The Lake
New latrines built at: Market
Maintain to high standard

Risk to self interventions: Strongly preferred safe water sources.(e.g. taps and filtrated water sites) but these were for water that was also safe to drink. Water only safe for bathing was not valued highly.
Risk to other interventions: Community members showed a strong preference for the introduction of fines for open defecation followed by new and accessible latrines.
A significant proportion of respondents were ignoring the payment aspects, therefore making it difficult to assess exact willingness to pay and work values for interventions.

This study highlighted gaps in schistosomiasis messaging and understanding. We recommend mass drug administration to be complimented by effective and evidence-based messaging on schistosomiasis transmission, prevention and treatment but also be sensitive to local issues of language and context in order to increase effectiveness.

Stakeholder meetings were held with community members and district officials, to further discuss the DCE results and identify facilitators and barriers for different interventions as well as an improved understanding on who should fund these interventions.The order of preference for the different interventions changed in discussions with groups, with interventions that benefitted the whole communities becoming more popular then the results from the individual based DCEs showed. Stakeholder meetings also highlighted that governments and/or districts should pay for the interventions but the community members where willing to pay or work for their upkeep.
Exploitation Route Recommendations:
Mass drug administration should be complimented by effective and evidence-based messages on schistosomiasis transmission, prevention and treatment but also be sensitive to local issues of language and context in order to increase effectiveness.
Improved availability of safe drinking water is key and highly valued.
In addition to MDA, WASH interventions of construction and maintaining latrines in easily accessible locations from either the market or place of abode.
Creating open defecation free communities by penalising open defecation and health education.
Interventions should be paid for by the district or national government, but community members are happy to pay or work for their maintainence.

Data are already being used to parameterise models in a follow on grant, the EPSRC grant.
Sectors Environment,Healthcare

Description Constructing Covid-19: Understandings, Attitudes and Health-Related Practices in Rural Uganda
Amount £20,009 (GBP)
Organisation Government of Scotland 
Department Scottish Funding Council
Sector Public
Country United Kingdom
Start 08/2020 
End 08/2021
Description ERC Consolidator Grant
Amount € 2,496,000 (EUR)
Funding ID 101045464 
Organisation European Research Council (ERC) 
Sector Public
Country Belgium
Start 04/2023 
End 03/2028
Description Lord Kelvin Adam Smith PhD studentship
Amount £70,900 (GBP)
Organisation University of Glasgow 
Sector Academic/University
Country United Kingdom
Start 10/2017 
End 09/2021
Description Mathematical tools to inform sustainable interventions against schistosomiasis in Uganda
Amount £458,099 (GBP)
Funding ID EP/T003618/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 10/2019 
End 09/2021
Description RSE Research Grant
Amount £10,000 (GBP)
Funding ID 1765 
Organisation Royal Society of Edinburgh (RSE) 
Sector Charity/Non Profit
Country United Kingdom
Start 12/2021 
End 11/2022
Title Impacts of host gender on Schistosoma mansoni risk in rural Uganda-A mixed methods approach 
Description Time to reinfection and microsatellite data for epidemiological and genetic analyses 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
Description MRC Uganda Virus Research Institute 
Organisation Medical Research Council (MRC)
Department MRC/UVRI and LSHTM Research Unit Uganda
Country Uganda 
Sector Academic/University 
PI Contribution MRC/UVRI are co-investigators on my MRC GCRF FA. We provide guidance and research support from all Glasgow PI and Co-Is.I have paid for my flight from other grants and combined visits to the MRC with ongoing work funded elsewhere. We provide capacity strengthening to two RAs employed by the grant at MRC/UVRI
Collaborator Contribution The main contributions are scientific, and are extensive, with social science knowledge, trainging and experience. The co-I from MRC/UVRI provides guidance and support free of charge. Vehicles are made available to us and we only pay a per diem for the driver.
Impact This is very much a multi disciplinary collaboration, combining social sciences, with my ongoing epidemiology, population genetics and diagnostics work.
Start Year 2017
Description Vector Control Division, Ministry of Health, Uganda 
Organisation Ministry of Health, Uganda
Country Uganda 
Sector Public 
PI Contribution During this MRC project: Co-investigators on my MRC GCRF FA.We work closely with VCD, MoH training technicians in economics discrete choice experiments (DCE) and working with them in the field to perform the DCE surveys.
Collaborator Contribution During this MRC project: The training took place in VCD buildings, and was co-organised by VCD technicians, taking up their time.
Impact Multi disciplinary: National and international policy, field epidemiology, parasitology, malacology, anthroplogy, economics, engineering - sanitation solutions.
Description Acting for Health Workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact An Acting for Health and International Society for Neglected Tropical Diseases employee joined us in Uganda for 10 days from 28th February 2018 to run an Acting for Health workshop with 16 members of the community where my MRC GCRF and ERC starting grant are being undertaken. Information that hs been gained during the early stages of the MRC GCRF grant have identified some key areas of misunderstanding about the transmission of bilharzia. This project was aimed at both engaging the community about hte research we are undertaking and providing feedback on some of our early findings to increase the impact of te research. A 5 day workshop was undertaken and then the 16 individuals involved put on a play for the community which was attended by at least 50-100 individuals including the village Chairman through to 10s of primary school children.
Year(s) Of Engagement Activity 2018
Description Community feedback sessions led by LS and EN 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Feedback presentations were given to the three communities on the WP1 results to large community gatherings of approximately 200 plus each.
Year(s) Of Engagement Activity 2019
Description Stakeholder meetings in communities, district and at the national and via zoom the international level. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Stakeholder meetings in communities, district and at the national level in person, and via zoom at an international level. These ran through the whole of February and March 2021 and were led by Moses Arinaitwe from the Vector Control Division, Ministry of Health, and Sande Silvester from the Uganda Virus Research Institute. These stakeholder meetings were redesigned due to Covid, with extensive in put from Dr Lamberton, Dr Pickering and Lazaaro Mujumbusi from the MRC project and assisted by Dr Alonso and Dr Janouskova from the EPSRC project. Extensive (one per day) interactive workshops with fisherfolk, students, women, opinion leaders were held in each of the three study communities. groups of 8-12 people per workshop.

In summary, at the start of February 2021, Moses and Sande mobilised each community. They then spent 6 days in total in each community, holding one workshop a day with different groups ( fisherfolk, School-aged children, women, opinion leaders and then a fifth day of a combined group) with 8-12 people. These workshops started with a short presentation of the MRC background, introducing schisto, the life cycle, and also the aims and methods of the study and the WP1 results. followed by an interactive workshop on the participants views on interventions for reducing risk to self (RTS) and risk to others (RTO), with a list of the interventions that the WP2 worked on. As a group they ordered these by what they think are the most popular/might be the best to put in place. This order was photographed and compared to our findings from the discrete choice experiment from WP2. After discussion of these, the top two RTS and RTO were chosen for further discussion with open ended questions such as:
1. How could these be put in place?
2. Who do you think should pay for these?
3. Who do you think should be responsible for maintaining these?
4. How much do you think you would pay for each of these in money/month or time/week
5. If time, what kind of work would you be interested/ happy to do for this? For putting in, or maintaining.
6. What type of work would you not do?

Then for each of these 4 interventions (2 RTS 2 RTO) they discussed facilitators and barriers in turn, in a conversational, workshop manner. Each person was asked in order around the room to suggest a barrier, until the group ran out of suggestions. These were then photographed. and then reordered by group consensus and photographed again. they then discussed facilitators for that intervention before moving on to the next intervention.
After the meeting all attendees were asked in private what % of people they thought would take up each intervention and how much did they think it would cost to put these into place. These individual level data will help inform the priors for the models being run in the EPSRC.

At the end of the five intense workshops, Sande and Moses gave a larger feedback session to a group of no more than 200 people (Covid-19 limits) with a more detailed presentation on a projector. This included more details on methods, numbers etc. and the full results of the WP1 and WP2, with plenty of time for questions.

The exact same format of hte workshops were held with the district and national stakeholders to assess difference between the hierarchies and to provide full feedback of the project to all. The national meetings included zooms and finally a full international meeting will be held at the end of March.

Sande and Moses reported excellent levels of involvement and a strong desire for change. qualitative and quantitative analysis is ongoing of impact, with decisions on what to model in the EPSRC project and applications for intervention trials being strongly influenced by these workshop sessions.
Year(s) Of Engagement Activity 2021