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

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.

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.

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.