Quantification of exposure to fecal contamination in open drains in four neighborhoods in Accra, Ghana

Abstract

In low-income countries, rapid urbanization adds pressure to already stressed water and sanitation systems that are critical to the health of communities. Drainage networks, designed for stormwater but commonly used for disposing of waste, are rarely covered completely, allowing residents to easily come into contact with their contents. This study used spatial mapping, documentation of physical drain characteristics, microbiological analysis of drain samples, and behavioral observation to comprehensively examine drains as a route of exposure to fecal contamination in four low-income neighborhoods in Accra, Ghana. A stochastic model of six likely exposure scenarios was constructed to estimate children's exposure to drain water. Regardless of the age of the child, any exposure scenario considered resulted in exposure to a high level of fecal contamination. Fecal contamination levels in drains were high (Escherichia coli: geometric mean (GM), 8.60 cfu log 10 /100 mL; coliphage: GM, 5.56 pfu log 10 /100 mL), and did not differ by neighborhood or physical drain characteristics, indicating that frequency of contact with drains, and not drain type or location, drives exposure risk.To mitigate health risks associated with this exposure, drains should be covered, with priority given to large concrete and small to medium dirt-lined drains that children were most commonly observed entering.

Assessment of Fecal Exposure Pathways in Low-Income Urban Neighborhoods in Accra, Ghana: Rationale, Design, Methods, and Key Findings of the SaniPath Study

“…Data from this substudy contributed to an assessment of exposure to fecal contamination from open drains described by Gretsch and others. 64 …”

“…60–64 This section highlights and synthesizes the key study findings and summarizes the quantitative assessment of exposure to fecal contamination for young children within the household substudy. A detailed description of this analysis and results by Wang and others can be found in a companion article.…”

“…Quantitative assessment of the risk associated with contact with open drains for children under 13 years of age (based on structured observations and microbiological analyses) demonstrated that any contact was associated with a high exposure to fecal microbes because of the magnitude of contamination ( E. coli geometric mean = 4.5 × 10 8 CFU/100 mL, range = 4.5 × 10 6 –1.5 × 10 11 of drain water). 64 …”

Where Children Play: Young Child Exposure to Environmental Hazards during Play in Public Areas in a Transitioning Internally Displaced Persons Community in Haiti

“…While distinct mechanisms for fecal pathogen transmission through public and private exposure pathways were suggested decades ago [18], research on exposure risks has focused almost exclusively on household settings [8,19,20,21,22]. Research has established that young children are exposed to feces by placing contaminated objects and soil in their mouth in the household and yard [20,23,24,25]. Children’s hands are contaminated by feces when crawling, touching soil and objects on the ground [26], and touching animal feces [25].…”

The Influence of Household- and Community-Level Sanitation and Fecal Sludge Management on Urban Fecal Contamination in Households and Drains and Enteric Infection in Children

“…High coverage of toilets discharging directly into the local environment combined with ubiquitous presence of open drains was associated with higher concentrations of human-specific pathogens, for example, GII norovirus, in drains in this study 49. Although structured observations from other low-income, urban areas suggest contact with drains is not common for this age group, QMRAs suggest that enteric infection may occur after a single contact 14,15,50,51. Further, children likely have frequent contact with the floors and ground both inside and outside the household, as well as contact with caregivers or other family members, all of which may provide direct or indirect exposure to feces from the outside environment 50,52.…”