UNC Water and Health Conference

Presenter: Wolfgang Mairinger


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.

unc_sanipath_2019
.pptx
Download PPTX • 37.32MB

UNC Water and Health Conference

Presenter: Sydney Hubbard


Rapid urbanization has led to a sanitation crisis in many low- and middle-income countries (LMIC). Studies of exposure to fecal contamination through different pathways have been conducted in LMICs. However, it is not clear whether exposure to fecal indicators (e.g. E. coli) from these pathways is associated with health outcomes (e.g. infection/illness). In March 2014, SaniPath in collaboration with the Christian Medical College (CMC) of Vellore, India conducted a cross-sectional 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 using membrane filtration method. Spatial coordinates were also collected for each sample. From March 2010 - February 2012, the MAL-ED study, a multi-site project examining enteric infections, enteric dysfunction, and growth outcomes, enrolled a birth cohort of 190 children in Old Town, Vellore. At least 16 stool samples were collected from each child over two years of follow up and were tested for multiple bacterial and viral pathogens. Symptomatic illness was recorded. Geospatial data for Old Town, including open drains, water pipe network, open defecation areas, were extracted from shape files provided by CMC. Under the assumption that the urban environment and the exposure behaviors did not change dramatically between the close of the cohort in 2014 and the SaniPath assessment the same year, each child in the MALED study was linked with the closest environmental samples for each sample type from the SaniPath study. Spatial variables like the distance to the closest open defecation site, cumulative open drain/street/waterpipe lengths within a 100-meter radius, and the number of children also enrolled in the cohort within a 100-meter radius 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 infections 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 preliminary findings that connect health outcomes to environmental exposure pathways and spatial information indicate differential risk factors for bacterial infections, viral infections, and symptomatic enteric illness in children under 2. 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.


Sanitation Challenge for Ghana Participants (Photo Credit: sanitationchallenge4ghana.org)

The Sanitation Challenge for Ghana is a program established to promote innovation and partnerships between Metropolitan, Municipal, and District Assemblies (MMDAs) and private and non-state sector actors to improve liquid waste management in low-income urban households in Ghanaian cities with populations over 15,000. The Challenge was first launched in 2015 by the Government of Ghana and is supported by IMC Worldwide (UK Department of International Development), IRC Ghana, and WASHealth Solutions. The Challenge consisted of two stages in which MMDAs submitted their work to be evaluated alongside their peers. Stage 1 consisted of 139 MMDAs with 17 being invited to participate in the second and final stage of judging. Private and non-state actors were eligible for entry if they had or will be partnering with at least one of the 17 Stage 2 MMDAs on a project related to liquid waste management. SaniPath partners were selected for recognition at both stages of the Challenge and include Accra Metropolitan Assembly, Kumasi Metropolitan Assembly, and Training, Research, and Networking for Development (TREND). Accra Metropolitan Assembly and Kumasi Metropolitan Assembly were recognized during Stage 1 with honorary prizes as Metropolitan Assemblies who are conducting essential work to improve liquid waste management in their respective cities.

Kumasi Metropolitan Assembly receiving the 1st prize worth £400k for innovations in liquid waste management. Photo credit

During Stage 2, Kumasi Metropolitan Assembly was selected as the 1st prize recipient of £400k for their innovative work on addressing liquid waste management to transform livelihoods in the urban center of Kumasi. The following quote was provided by Sanitation Challenge for Ghana on the work Kumasi Metropolitan Assembly had conducted over the challenge period:

Kumasi Metropolitan Assembly – 1st winner, £400,000 for its innovative partnership with the private sector, use of aquaculture, skilled and knowledgeable staff and strong support and leadership commitment from the Mayor. Overall, the Assembly showed an outstanding commitment to all parts of the sanitation value chain.” – Sanitation Challenge for Ghana

SaniPath partner TREND receiving the Special Prize for private partners (photo credit: Habib Yakubu)

TREND was also recognized during Stage 2 of the challenge as a private partner to MMDAs whose work aims to improve liquid waste management across urban centers. TREND has facilitated trainings and managed the deployment of two SaniPath Exposure assessments, both in Accra and Kumasi, in late 2018. TREND was awarded $10,000 for their work as a SaniPath Training Hub and the capacity building and data collection work performed alongside Kumasi Metropolitan Assembly.