Risk of Exposure to Fecal Contamination in 10 Neighborhoods Across Dhaka, Bangladesh

CL Moe, J Green, S Raj, Y Wang, N Amin, S Ali, M Rahman, I Hasan, Z Hasan, S Haque, G Joseph American Society of Tropical Medicine and Hygiene Conference (October 2018)

Dhaka, Bangladesh has experienced rapid population growth and challenges meeting sanitation service demands. Poor sanitation and fecal sludge management can lead to fecal contamination in the urban environment. To understand risk of exposure to fecal contamination, an assessment of 10 environmental pathways was conducted using the SaniPath Tool. Data were collected from 10 neighborhoods (6 low-income, 2 mixed-income, and 2 high-income) throughout Dhaka between April-June 2017. 1000 environmental samples were collected from shared latrines, public play areas, produce in markets, street food, open drains, flood waters, surface waters, bathing water, municipal water, and non-municipal water. Samples were analyzed using IDEXX-Colilert-24® Quanti-Tray/2000 to determine most probable number (MPN) of E. coli. Behavior surveys were conducted with households, school children, and community groups to understand interaction with the environment. Using Bayesian methods, the behavioral and microbiological data were used to estimate the percentage of the population exposed and mean dose of fecal exposure (E. coli) for each environmental pathway in each neighbourhood. For adults, consumption of raw produce was the dominant exposure pathway (i.e. makes greatest contribution to total exposure) in 6 of the 10 neighborhoods. The percentage of adults exposed to fecal contamination through ingestion of raw produce ranged from 78-99% and the mean dose ranged from 104.8 to 107.5 MPN of E. coli ingested/month. The most common dominant pathway of exposure amongst children (8/10 neighborhoods) was accidental ingestion of drain water from playing in, or passing through, open drains (up to 94% exposed; mean dose of 107.8 MPN of E. coli ingested/month). Ingestion of fecal contamination via produce and street food was a high risk throughout Dhaka, while exposure to fecal contamination via municipal drinking water was mainly greater risk for those living in the south of the city. These results can guide city-wide WASH programming to prioritize interventions aimed at dominant exposure pathways and increase the potential for public health impact.

SaniPath Project Launch: Kumasi, Ghana

In partnership with Training, Research and Networking for Development (TREND) Group, the SaniPath Project was launched in Kumasi, Ghana in July ’18. This project involves TREND conducting training of Kumasi Metropolitan Assembly (KMA) members and performing project management activities for a deployment in 4 neighborhoods throughout Kumasi. KMA will be conducting the fieldwork and collaborating with Kwame Nkrumah University of Science and Technology (KNUST) to perform laboratory analyses. These activities are part of the establishment of TREND as a SaniPath Training Hub for the West-African region.

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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