An inter-disciplinary approach to understanding the contribution of household flooring to disease burden in rural Kenya

Lead Research Organisation: London Sch of Hygiene and Trop Medicine
Department Name: Infectious and Tropical Diseases


Access to adequate, safe and affordable housing plays a fundamental role in human health. This includes thorough limits our exposure to infectious diseases such as those that cause diarrhoea, which remains a leading cause of death in children under five. Conventional approaches to reducing environmental exposure to faecal pathogens include ensuring universal access to safe water and basic sanitation. Recent evidence has suggested that this alone may be insufficient to reduce the high levels of environmental contamination seen in poor rural communities, and that transformative cross-sectoral approaches will be required to see real impacts in child health. For example, these approaches fail to address the fact that most poor rural homes have rudimentary (earth, sand or dirt) floors that are difficult to sanitise, providing an ideal environment for the survival of faecal pathogens and other parasites. These floors can also host parasitic infections including intestinal nematodes and sand fleas, both of which are responsible for considerable morbidity and poor quality of life.

We propose to examine flooring and its impact on enteric and parasitic diseases in three culturally and environmentally diverse settings in Kenya, and aim to address two related questions:
1. What is the importance of household flooring as a driver of enteric and parasitic infection risk in rural communities, and does this vary across wider social and environmental contexts?
2. Can infection risk be mitigated by replacing existing rudimentary (earth, sand or dirt) floors with improved (sealed, washable and durable) materials, and what additional behaviour changes are required to ensure impact?

We expect that successful installation and ongoing maintenance of improved flooring will reduce the transmission of enteric and parasitic infections, by preventing direct exposure and through an intermediate effect of improved domestic hygiene. This will however be influenced by local context. A priority in each setting will therefore be to explore the interplay between domestic flooring, water and sanitation infrastructure, domestic hygiene behaviours, and the wider socio-cultural and environmental context.

Our planned approach involves comprehensive formative research, intervention development conducted in collaborative partnership with recipient communities and key stakeholders, and then implementation trials to test the effects, feasibility and acceptability of the resulting intervention. We will assess the impact of the intervention on a range of child health outcomes, including prevalence of enteric and intestinal worm infections, prevalence of tungiasis, and incidence of gastrointestinal illness. We will also monitor levels of environmental contamination, and explore the impact of the intervention on domestic routines and self-reported wellness. During implementation, we will work with recipients and stakeholders at community, regional and national level to assess the extent to which interventions are acceptable to target communities, feasible given existing resource constraints, and can be scaled-up across Kenya and elsewhere. This includes work undertaken to understand options for scale-up should the intervention prove successful.

This study is the first of its kind to comprehensively assess feasibility and effects of combining improved flooring technologies with tailored behaviour change programming on a wide range of parasitic and enteric outcomes. In doing so, we aim to provide important policy and technical guidance on the impact and effectiveness of new transformative approaches to community health. This is an important first step towards the establishment of transformative, community-driven and cross-sectoral approaches to building out water, sanitation and hygiene-related diseases.

Technical Summary

The quality and environmental context of housing provides important conduits through which social and environmental inequalities can translate into health inequity. We hypothesise that rudimentary flooring is an under-recognised contextual driver of health in poor rural communities, augmenting exposure to enteric and parasitic pathogens. This inter-disciplinary study seeks answer the question in what contexts does household flooring act as a driver of infection risk, and how can we intervene to mitigate this? We plan to work in three culturally and epidemiologically distinct settings across Kenya to evaluate enhanced flooring packages (EFPs) that include the provision of an improved floor, accompanied by a participant-informed behaviour change programme. In each site, formative research will focus on refining flooring specifications and technologies, and behaviour change needs. Participatory co-development approaches will then be used to design final intervention. Cluster randomised intervention trials will be used to assess the effects, feasibility and acceptability in each site. In total, 225 households will be randomised to receive the intervention or not. Primary outcomes include the prevalence of enteric infections, STH and tungiasis, assessed by repeat cross-sectional surveys. Secondary outcomes include incidence of gastrointestinal illness, environmental contamination and subjective wellbeing. A nested process evaluation will explore implementation fidelity and uptake, acceptability, feasibility and cost, whilst sustainability and scalability will be explored using an implementation science approach. Funders and governments still require clear policy and technical guidance on the impact and effectiveness of new transformative approaches to reducing the burden of diseases associated with poor water, sanitation and hygiene. This evaluation will be among the first to provide policy information on the potential impact of flooring improvements on community health.

Planned Impact

The proposed research has a number of potential direct beneficiaries, ranging from the global through the national to the individual level:

At the global level, a first beneficiary is the World Health Organization (WHO), and the proposed research has the ambition to challenge and change WHO's guidelines on sanitation and health. The WHO has recently published its strategy on WASH for accelerating and sustaining progress on neglected tropical diseases although these do not mention flooring. The proposed study seeks to move beyond conventional water and sanitation, and provide proof-of-principle for improving housing conditions to reduce transmission of multiple infections.

A second group of global beneficiaries are members of the global WASH sector, who are seeking guidance on next steps towards developing a broader, transformative WASH strategy that addresses wider environmental contamination. Third, looking to the housing sector, the majority of current research focuses on urban populations, and findings from this study would help to demonstrate market opportunities for investing in flooring for rural communities.

A fourth group of global beneficiaries are members of the global NTD coalition. Since the 2012 London Declaration brought this disparate community together, the focus of STH control has been through preventive chemotherapy and WASH has played a back seat. Demonstrating the importance of reducing environmental contamination to prevent reinfection may help change the approach to STH control.

The fifth group of global beneficiaries are funders, including the Bill & Melinda Gates Foundation, DFID and USAID, who are supporting national government to implement WASH-related interventions but are seeking new strategies and approaches. The proposed study will provide the first evidence as to the potential of reducing transmission through a flooring intervention, and the optimal strategy as to how this might be achieved. This evidence will help inform subsequent funding and resource allocation.

At the country level, the main beneficiary is the Government of Kenya (GoK), including the Ministries of Health and of Housing. The proposed study will inform the design and scaling-up of new WASH strategies not only Kenya, but also many other high burden countries. In 2009, the GoK launched its national school-based deworming programme (NSBDP), which successfully treated over 4.6 million preschool and school children in 2013. Notwithstanding these achievements, there are concerns that the school-based programme will need to continue indefinitely if allied WASH strategies cannot be developed to help reduce reinfection rates.

At the local level, communities will benefit from the study. Both intervention and control households will receive a new floor by the end of the study. In addition to the positive financial impact fo this, it should lead to health and wellbeing impacts including reduction in infection risk. CHWs will also benefit from the study as they will have the opportunity to broaden the scope of their activities and contribute to efforts to control tungaisis in their communities. We will work with the GoK to develop relevant training materials for CHWs, which could be readily adapted to other countries. Local masons will be trained and provided with a potential new means of income beyond the duration of the study.

A final group of beneficiaries are staff working on the project who will be able to develop a range of skills (e.g. project and finance management, communication, trial design and analysis, epidemiology) appropriate to their role in the project, which will be transferable to other work and sectors in the future. Specific individuals will also be able to gain training in clinical trials, monitoring and evaluation and epidemiology, and behavioural science including local students recruited under the LSHTM Collaborative Centre scheme which facilitates reduced fees and multi-site tuition.