Overview of the SaniPath Exposure Assessment Process and Tool

The SaniPath Exposure Assessment Tool ("the Tool") aims to assess exposure to fecal contamination in urban, low-income settings. The Tool was developed by the Center for Global Safe Water at Emory University with funding from the Bill & Melinda Gates Foundation. The Tool guides users in collecting data on exposure to fecal contamination in urban and peri-urban neighborhoods and synthesizes the data for community, government, and service providers’ decision-making. The Tool is publicly available and is intended for non-governmental organizations, funders, and government institutions.

Background

Rapid urbanization has led to a growing sanitation crisis in urban and peri-urban areas of low-income countries. Currently, over half of the global population resides in urban areas, with cities in Asia and Africa projected to experience the greatest increase in population.¹ Rapid population growth in developing countries has outpaced existing infrastructure, including water and sanitation systems, leading increasing numbers of urban dwellers, especially those in informal settlements, to live in very polluted environments.^2-4 Despite the considerable sanitation needs of urban and peri-urban communities, there are little data to inform strategies to mitigate risks of fecal exposure in developing countries. Consequently there is a need for site-specific evidence to help make decisions about sanitation investments.

The SaniPath team conducted an in-depth assessment of exposure to fecal contamination in Accra, Ghana along multiple pathways. The data that were collected have helped to inform an understanding of the broken sanitation chain in urban, low-resource settings. In many situations, the ability of decision makers to characterize sanitation issues is limited to desk work or to relying on consultants to provide guidance. Therefore, the SaniPath Exposure Assessment Tool is designed to be accessible and understood by mid-level civil servants with a variety of scientific backgrounds (including environmental health officers, local government administrators, program managers, and lab technicians). The result is a “scaled-down” version of our in-depth assessment that can enable a wider audience to characterize sanitation in urban and peri-urban settings.

The SaniPath Exposure Assessment Tool methodology distinguishes itself from other methodologies in the following ways:

● It focuses on sanitation conditions and exposure to fecal contamination.

● It is designed specifically for use in high-density urban settlements.

● It includes environmental microbiology methods to quantify magnitude of fecal contamination in specific environmental pathways.

The objectives of the SaniPath Exposure Assessment Tool are to:

● Generate reliable data on exposure to fecal contamination in low-income, urban neighborhoods

● Synthesize these data for community, government, and service providers’ decision-making

The results of this assessment can be used to characterize a neighborhood or city according to a matrix of fecal exposure pathways. The outputs will serve as a simplified, but still informative, means of identifying priorities for sanitation investments or interventions. The Tool will allow the following two primary ways of comparing risks:

● Comparing neighborhoods (either aggregate risk or identify the biggest pathway risk for each neighborhood)

● Comparing pathways within a neighborhood

The exposure assessment is designed to be completed within one to three months, depending on number of neighborhoods selected for the assessment.

System Requirement Specifications

The SaniPath Exposure Assessment Tool uses a combination of printed paper forms and mobile data collection methods for conducting the preliminary assessment, surveys, sample collection, and sample processing.

To utilize mobile data collection, the user should have access to Android devices/tablets and must install the KoBoCollect application (KoBoToolBox, Harvard Humanitarian Initiative). Detailed instructions on installing the software and utilizing the mobile data collection tool are available in the mobile data collection folder of the SaniPath Tool Implementation Package.

All of the forms and surveys necessary to carry out the SaniPath exposure assessment are available as PDFs and can be downloaded and printed at from the SaniPath Google Drive folder. If your computer does not already have a PDF reader installed, Adobe Reader can be downloaded for free.

The Approach

The SaniPath Exposure Assessment Tool, as well as training materials and resources, are available at in the SaniPath Google Drive folder. The major components included in the SaniPath Folder are: (1) SaniPath Exposure Assessment Tool, which includes implementation guides; protocols for behavioral data collection, environmental sample collection, and laboratory analysis; mobile data collection instructions; and laboratory forms and behavioral surveys; and (2) Training guides and materials, which includes PowerPoint presentations and handouts for training enumerators and laboratory staff (3) Quality Control resources, which include a dashboard for monitoring data and other tools to ensure a deployment of the SaniPath Tool goes smoothly.

The exposure assessment methodology guides the user through various modules to plan, collect data, and analyze environmental samples. The methodology characterizes the behavior of adults and children in the public domain along ten different pathways:

• Surface water (rivers/lakes/ponds)
• Open drains
• Flood water
• Drinking water
• Public/community/shared latrines
• Raw Produce (vegetables)
• Street Food
• Bathing water
• Ocean water
• Soil

In addition, the methodology involves collecting and processing environmental samples from these same pathways. Each pathway listed above has an environmental sampling component to complement the behavioral data (with the exception of flood water because flood water samples are often difficult to collect). Soil samples from a variety of public locations are also included in environmental sampling. The Tool does not include pathways of exposure in the private domain or those strongly related to personal hygiene as they are less influenced by public intervention.

The behavioral and environmental microbiology results are then combined using a novel exposure risk profile method. The software will automatically conduct all analysis and produce graphical representations of the data.

The main outputs of the exposure assessment that users can expect to create includes data visualization that combines the environmental microbiological data and the behavioral data (how many people are exposed and how often) to quantify risks of key exposure pathways for comparison. The SaniPath Exposure Assessment Tool will generate risk profiles in the form of “people plots”. People plots show the proportion of people exposed to fecal contamination as well as the magnitude of exposure for each exposure pathway. The shade of red of the people plot corresponds with the level of exposure/dose (i.e. the darker the shade, the higher the exposure). The number of red people shows the proportion of population exposed to fecal contamination while grey people represents unexposed population. Other outputs of the Tool are key summary statistics of behavioral and environmental data, as well as information about behavior and access to sanitation facilities in the city.