Date Published: October 11, 2017
Publisher: The American Society of Tropical Medicine and Hygiene
Author(s): Katharine Robb, Clair Null, Peter Teunis, Habib Yakubu, George Armah, Christine L. Moe.
Rapid urbanization has contributed to an urban sanitation crisis in low-income countries. Residents in low-income, urban neighborhoods often have poor sanitation infrastructure and services and may experience frequent exposure to fecal contamination through a range of pathways. There are little data to prioritize strategies to decrease exposure to fecal contamination in these complex and highly contaminated environments, and public health priorities are rarely considered when planning urban sanitation investments. The SaniPath Study addresses this need by characterizing pathways of exposure to fecal contamination. Over a 16 month period, an in-depth, interdisciplinary exposure assessment was conducted in both public and private domains of four neighborhoods in Accra, Ghana. Microbiological analyses of environmental samples and behavioral data collection techniques were used to quantify fecal contamination in the environment and characterize the behaviors of adults and children associated with exposure to fecal contamination. Environmental samples (n = 1,855) were collected and analyzed for fecal indicators and enteric pathogens. A household survey with 800 respondents and over 500 hours of structured observation of young children were conducted. Approximately 25% of environmental samples were collected in conjunction with structured observations (n = 441 samples). The results of the study highlight widespread and often high levels of fecal contamination in both public and private domains and the food supply. The dominant fecal exposure pathway for young children in the household was through consumption of uncooked produce. The SaniPath Study provides critical information on exposure to fecal contamination in low-income, urban environments and ultimately can inform investments and policies to reduce these public health risks.
Results of the SaniPath Study are presented in a series of articles and others that are in preparation.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.80 Future manuscripts will describe the quantitative assessment of exposure to fecal contamination in the public domain for both adults and children.
Previous studies of Accra have concluded that the open drains posed the greatest risk to public health.50 The SaniPath Study also observed substantial risk associated with any contact with open drains because of the magnitude of fecal contamination in these drains.64 However, for young children, our results indicate that the dominant exposure pathway was through food and demonstrate the critical link between poor sanitation and food safety. This has important implications for the “WASH sector” – that typically includes only water, sanitation, and hygiene and ignores food safety. Urban agriculture is a key contributor to the food supply in many cities in sub-Saharan Africa, and wastewater irrigation is a common practice.39 Yet, our study reveals that this exposure pathway combines high frequency of exposure and high “doses” of fecal contamination – making it a high-risk pathway that should be a priority for intervention (Wang and others, companion paper). Furthermore, produce can be a vehicle for fecal contamination to move across the city from poor urban neighborhoods into middle- upper-income neighborhoods due to the fact that markets may sell produce grown in these neighborhoods all over the city. Finally, the large proportion of adults and children that reported regularly consuming produce also points to a shift away from traditional diets among urban populations. This may be due in part to heavily reliance of poor populations on street-vended food with entrees that often included salads.81 Another shift in consumption habits is represented by the low rates of reported consumption of piped municipal water, a finding that was also observed by Stoler and others.82