A Faecal Contamination Index for interpreting heterogeneous diarrhoea impacts of water, sanitation and hygiene interventions and overall, regional and country estimates of community sanitation coverage with a focus on low- and middle-income countries.

Paul R Hunter,Annette Prüss-Ustün,Jennyfer Wolf,Bruce Gordon,Kate Medlicott,Richard Johnston

doi:10.1016/j.ijheh.2018.11.005

Abstract

ObjectivesThe impact on diarrhoea of sanitation interventions has been heterogeneous. We hypothesize that this is due to the level of prevailing faecal environmental contamination and propose a Faecal Contamination Index (FAECI) of selected WASH indicators (objective 1). Additionally, we provide estimates of the proportion of the population living in communities above certain sanitation coverage levels (objective 2).MethodsObjective 1: Faecal contamination post-intervention was estimated from WASH intervention reports. WASH indicators composing the FAECI included eight water, sanitation and hygiene practice indicators, which were selected for their relevance for health and data availability at study- and country-level. The association between the estimated level of faecal environmental contamination and diarrhoea was examined using meta-regression. Objective 2: A literature search was conducted to identify health-relevant community sanitation coverage thresholds. To estimate total community coverage with basic sanitation in low- and middle-income countries, at relevant thresholds, household surveys with data available at primary sampling unit (PSU)-level were analysed according to the identified thresholds, at country-, regional- and overall level.ResultsObjective 1: We found a non-linear association between estimated environmental faecal contamination and sanitation interventions’ impact on diarrhoeal disease. Diarrhoea reductions were highest at lower faecal contamination levels, and no diarrhoea reduction was found when contamination increased above a certain level. Objective 2: Around 45% of the population lives in communities with more than 75% of coverage with basic sanitation and 24% of the population lives in communities above 95% coverage, respectively.ConclusionsHigh prevailing faecal contamination might explain interventions' poor effectiveness in reducing diarrhoea. The here proposed Faecal Contamination Index is a first attempt to estimate the level of faecal contamination in communities. Much of the world's population currently lives in faecally contaminated environments as indicated by low community sanitation coverage.

Highlights

Drinking water, sanitation and hygiene (WASH) interventions may amongst others provide community water access or household water connections, source or point-of-use water quality improvements, on-site sanitation or sewer connections, handwashing promotion or general hygiene education (Fewtrell et al, 2005)
From the World Health Organization (WHO)/UNICEF Joint Monitoring (JMP) data repository we identified a total of 111 countries for which survey microdata on use of basic sanitation services at primary sampling unit (PSU)-level were available
We propose a first attempt to estimate the level of faecel contamination in an intervention setting

Summary

Introduction

Sanitation and hygiene (WASH) interventions may amongst others provide community water access or household water connections, source or point-of-use water quality improvements, on-site sanitation or sewer connections, handwashing promotion or general hygiene education (Fewtrell et al, 2005). The SaniPath study, for example, has provided insights into pathways of exposure to faecal contamination, has revealed high levels of faecal environmental contamination in low-income settings and identified the consumption of contaminated food as the main fecal exposure pathway for children (Robb et al, 2017). Another example is faecally contaminated drinking water which can result from inadequate sanitation and hygiene and which has been shown to be a frequent problem even in so-called “improved” drinking water sources (Bain et al, 2014). Public and occupational settings might offer important additional exposure routes through for example contaminated soil and open drains (Antwi-Agyei et al, 2016; Berendes et al, 2018)

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