The effects of water and sanitation interventions in low and middle income countries

The effect of interventions on the incidence of disease is seldom linear. This is because one person’s risk affects another person’s risk. In the case of vaccination we refer to increasing then decreasing returns to scale as a ‘herd-effect’. It is likely that something similar applies to water and sanitation interventions and their effect on health. This project will proceed as follows:

1. Update systematic reviews of the effectiveness of water and sanitation interventions in low and middle income countries: a. Rural b. Urban
2. Refine published model of coverage and type of sanitation and water intervention on disease.
3. Populate models with data from systematic reviews undertaken in number 1).
4. Draw up proposal for further studies.

This PhD will be based in the NIHR Global Health Research Unit on Improving Health in Slums that is addressing health services in slums in 4 countries (Nigeria, Kenya, Pakistan, Bangladesh). The student will be embedded in an interdisciplinary, international team and have access to training programmes.

The methodology and techniques to be employed are as follows:

1) Overview of the literature on ‘herd-effects’ / ‘neighbourhood effects’ and risk of infection.
2) Update systematic reviews of water and sanitation interventions with health outcomes and classify by methodology of study e.g. cluster trials versus database studies versus non-experimental cohort studies.
3) Model effects by intervention intensity and coverage based on et Lilford et al 2016 http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)318487/fulltext
4) Design follow on studies.