American Society of Tropical Medicine and Hygiene 2019

November 20-24, 2019


Yuke Wang, Sydney Hubbard, Gagandeep Kang, Suraja Raj, Habib Yakubu, Arun Karthikeyan, Senthil Kumar, Venkata R. Mohan, Christine Moe

Emory University, Atlanta, GA, United States, Christian Medical College of Vellore, India, Vellore, India


Rapid urbanization has led to a sanitation crisis in many low- and middle income countries (LMIC). In March 2014, SaniPath in collaboration with the Christian Medical College (CMC) of Vellore, India conducted an exposure assessment in Old Town, a dense, urban unplanned settlement in Vellore. A total of 191 samples were collected from open drains, drinking water, public latrines, soil, raw produce, bathing water, child handrinse, and toy feeding spoon rinse and analyzed for E. coli. From March 2010 - February 2012, the MAL-ED study, a multi-site project examining enteric and growth outcomes enrolled a birth cohort of 190 children in Old Town. Multiple stool samples were collected from each child over two years of follow up and tested for bacterial and viral pathogens. Symptomatic illness was recorded. Each child in the MAL-ED study was linked with the closest environmental samples from the SaniPath study. Spatial variables, like the distance to the closest open defecation site, were generated. Generalized linear models were used with the bacterial infection rate, viral infection rate, and symptomatic illness rate as outcomes and environmental fecal contamination from different pathways and spatial variables as covariates. E. coli concentration from the closest public latrine and the distance to the closest open defecation site were significant predictors of bacterial infection rate in children. The sum of the open drain lengths within a 100-meter radius of the child, as well as the sum of street lengths within a 100-meter radius of the child, were significant predictors of viral infections in children. The E. coli concentration of the closest piped water was the only significant predictor of symptomatic illness in children. These results highlight the need for safe excreta management in dense, urban settings to prevent bacterial infections, while contaminated drinking water seems to be a major driver of symptomatic illness in this population. Human congestion, as proxied by summative surrounding street lengths and open drains, is a key risk factor for viral infection.

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The WHO and UNICEF position paper Implications of recent WASH and nutrition studies for WASH policy and practice summarized three high-quality studies in the WASH sector that resulted in little or no impact on reducing childhood diarrhea and stunting. The paper aimed to contextualize the findings and distill the implications for future WASH investments.


The report highlighted that oftentimes fecal contamination of produce is not considered when designing and implementing interventions despite prior evidence that this is a dominant exposure pathway in many settings. The paper cites SaniPath as the source of this important piece of evidence.

The evidence generated through SaniPath's work is increasing awareness about this major exposure pathway and contributing to influential position papers such as this one. The data generated from deployments is encouraging policies and practices to address food safety issues that arise from fecal contamination along the value chain.

UNC Water and Health Conference

Presenter: Habib Yakubu


Periodically, resource-challenged municipal governments in urban areas of low-income countries face decisions on how to set priorities for sanitation investments and focus resources for impact. This is primarily due to their lack of knowledge of existing innovative evidence- based sanitation tools. SaniPath exposure assessment tool evaluates the public health risks from poor sanitation and unsafe fecal sludge management in low-income urban areas. It has been deployed in 43 neighborhoods in 9 cities ; Accra, Ghana; Vellore, India; Maputo, Mozambique; Siem Reap, Cambodia; Dhaka, Bangladesh; Atlanta, United States; Lusaka, Zambia; Kampala, Uganda and Kumasi; Ghana. The most recent shit flows diagram indicates that only an estimated 45% of the fecal sludge is treated. Four neighborhoods of varying geographic and socio economic characteristics were selected for the deployment of the SaniPath tool based on extensive engagement with Kumasi Metropolitan Assembly (KMA). Trained environmental health assistants collected environmental samples and behavior data from multiple pathways in Moshie Zongo, Dakodwom, Fante Newtown and Ahodwo. The nine pathways investigated were; river water, street food, raw produce, drinking water, bathing water, open drain water, soil, public latrines and floodwater. The unit of analysis of the tool is exposure to fecal contamination. Exposure is a measurement of the average amount of E.coli ingested per month (dose) and the percent of the population exposed to fecal contamination per pathway. The most common dominant exposure pathway for children across all the four neighborhoods was open drains. A large percent of the child population was exposed, ranging from 85% to 95% and a high average dose between 10^6 to 10^8 colony forming units (CFU). For adults, the most dominant pathway varied across all the four Page 50 of 56 neighborhoods. Raw produce was the most common dominant pathway in Moshie Zongo, with 78% of the adult population exposed, and a high dose of >10^7. Bathing water was the most dominant pathway in Fante Newtown; with 81% of the population exposed and a high dose of >10^7. Open drains was the most dominant pathway in Ahodwo and Dakodwom with population exposed >61% and high dose values > 10^6. KMA has used this information to take immediate action in two neighborhoods. Firstly, they investigated the source of contamination of a surface water and sanctioned the property owner who had illegally connected directly a shared latrine’s fecal waste into a community river. Secondly, KMA rolled out a school hygiene program to educate primary school students on good hygiene practices within their school compound, in public spaces around open drains and in school toilets. There are other ongoing plans to use the results to inform their sanitation planning, practice and investments. These actions, show that with commitment and access to evidence based sanitation tools, municipal governments in urban areas are capable of using evidence based sanitation tools to prioritize and focus their sanitation investments.


SaniPath Training Hub Evidence to Action
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