Developing a locally viable water filtration method to provide safe drinking & bathing water from Lake Victoria in a Schistosoma mansoni endemic area.

strategic priority area:Water engineering. Design/optimisation of technologies relating to water resource management, treatment and distribution systems (including waste water and sewerage).
Keywords:WASH, filtration, disease, sustainable, schistosomiasis

Schistosomiasis is a neglected tropical disease infecting over 240 million people, mainly in sub-Saharan Africa, causing approximately 200,000 deaths a year and severe illness in millions of children and adults. Transmission is intrinsically linked to poverty, driven by poor water, sanitation and hygiene (WASH) conditions. Individuals acquire infections when they contact fresh water containing cercariae, the infective larval stage of the parasite, which burrow directly through the skin upon contact. Water contact occurs through behaviours such as water collection and bathing. Water contamination, and hence disease transmission through water contact, is high in areas with inadequate sanitation with the parasite eggs excreted in human urine and stool. Presently, mass drug administration is the main form of control, but improved WASH facilities are required to interrupt transmission and reduce reinfection. Biofiltration and slow sand filters are simple, cost effective biotechnologies available for drinking water purification. The complex biofilms that form within the biofilters breakdown nutrients and/or eliminate pathogens (such as viral and bacterial pathogens) to make the water safe for drinking. However, the biology is often not fully understood and therefore not fully optimised for efficiency or targeted removal of particular pathogens and/or contaminants. For example, slow sand filters would be expected to also remove parasites such as Schistosoma larval stages from the water. However, these technologies have yet to fully optimised and tested in Schistosoma endemic areas for the treatment of water to reduce schistosomiasis transmission and a range of other water borne contaminants.
This PhD will address questions surrounding the design, effectiveness, and uptake of a low-cost water filtration system to extract and treat lake water by passage using low cost, low energy biofilters to make it safe for drinking, bathing and other domestic uses. The project will involve 1) working in the laboratory in the UK to design, test and optimise the filtration methods using cercariae from laboratory life cycles. Field work in Uganda will focus on 2) identifying suitable, locally available materials for future local manufacturing, enhancing sustainability of future interventions, as well as 3) performing parasitological and epidemiological studies with households from endemic areas to assess filtration usage and reinfection levels in families with and without access to treated water.

The overarching aim is to develop a biofiltration system, by optimising the biology to remove Schistosoma and other water borne contaminants, that can logistically and affordably manufactured within endemic communities, to efficiently treat infectious lake water to make it safe for drinking, bathing and domestic use.
Specific objectives include:
1: Optimising the efficacy of slow-sand biofilters for the removing and/or inactivating schistosome cercariae in the laboratory
2: Performing qualitative surveys in communities to identify preferences for water filtration design and location
2: Identify materials and skills for the future manufacturing of low-cost filters using locally sourced materials and labour.
3: Monitor filtration usage and Schistosoma mansoni infection and reinfection levels in families in endemic communities in Uganda with access to the new filtration systems and those with no additional interventions.

Skills will be gained in environmental engineering and microbiology, parasitology, field epidemiology and with an understanding in social sciences, health economics and local manufacturing gained through our collaborators at the Ugandan Virus Research Institute.