Comparison of SaniPath exposure assessments in low-income urban areas in eight countries

American Society of Tropical Medicine and Hygiene 2019

November 20-24, 2019

Wolfgang Mairinger, Yuke Wang, Suraja Raj, Habib Yakubu, Casey Siesel, Jamie Green, Sarah Durry, Christine Moe

Emory University, Atlanta, GA, United States

The SaniPath exposure assessment tool compares risks of exposure to fecal contamination in urban environments across multiple exposure pathways. The tool has been deployed in 39 neighborhoods in 8 cities: Accra, Ghana, Vellore, India; Maputo, Mozambique; Siem Reap, Cambodia; Dhaka, Bangladesh; Atlanta, United States; Lusaka, Zambia; and Kampala, Uganda. Ten exposure pathways were investigated (open drains, ocean water, surface water, floodwater, public latrines, soil, bathing water, raw produce, drinking water, and street food) through behavior surveys and environmental sample analyses. Exposure was expressed as monthly dose (average amount of fecal contamination ingested as measured by E. coli colony-forming units [CFU]) and the percent of population exposed to fecal contamination for each pathway. Magnitude of fecal contamination, frequency of exposure behavior, and estimated fecal exposures were compared across pathways, neighborhoods and cities. The most common dominant exposure pathways for adults were raw produce, open drains, and street food and for children were open drains, produce, and floodwater. For produce, the dose was usually very high (>106 CFU/ month), and a large percent of the population was exposed (>80%). For street food, average E. coli concentration ranged from 101.3 CFU/serving in one neighborhood in Lusaka, Zambia to 105.5 CFU/serving in one neighborhood in Dhaka, Bangladesh. Exposure to open drains resulted in high doses (>104 CFU/month), but the population exposed varied (5%-92%) even within the same city. Exposure to fecal contamination via floodwater, usually affected a high percent of population (>80%) but had variable doses (102.5-1010 CFU/month). Both dose and percent of population exposed varied for public latrines and municipal piped water. This information can help city governments choose effective interventions to reduce the risk of exposure to fecal contamination. Widespread risks from contaminated produce and street food within and across cities underscore the link between excreta management and food safety and need for global action.

Fecal Exposure Assessment in Informal Settlements and Formal Neighborhoods of Siem Reap, Cambodia

J Green, S Raj, Y Wang, D Duong, M Yakushima, S Chhun, H Yakubu, J Michiel, J Wicken, CL Moe

UNC Water and Health Conference (October 2017)

At the 2017 UNC Water and Health Conference in Chapel Hill, North Carolina, Jamie Green presented a poster on an assessment of Exposure to Fecal Contamination in Informal Settlements and Formal Neighborhoods of Siem Reap, Cambodia. The CGSW’s Sanipath Tool was used to assess the risk of exposure to fecal contamination in 5 environmental pathways in 5 neighborhoods (3 formal and 2 informal settlements). Overall, there were large variations in exposure risks within formal neighborhoods and informal settlements. Results show that raw produce posed one of the greatest risks of exposure to fecal contamination across all five neighborhoods (100% of adults exposed to dose ranging from 7.59E05 to 1.78E07 CFU/month from produce). Participants in all neighborhoods reported bottled water and well water as main sources of drinking water, while few reported drinking municipal water. No E. coli was found in municipal water, while bottled water and well water had moderate amount of E. coli. The lowest dose of exposure for floodwater was found in the only neighborhood with a drainage system (4.79E02 CFU/month). Results from this study provide evidence for decision makers to prioritize efforts to reduce exposure to fecal contamination in Siem Reap.

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