Sara J. Marks

Fecal Contamination and Diarrheal Pathogens on Surfaces and in Soils among Tanzanian Households with and without Improved Sanitation

Little is known about the extent or pattern of environmental fecal contamination among households using low-cost, on-site sanitation facilities, or what role environmental contamination plays in the transmission of diarrheal disease. A microbial survey of fecal contamination and selected diarrheal pathogens in soil (n = 200), surface (n = 120), and produce samples (n = 24) was conducted in peri-urban Bagamoyo, Tanzania, among 20 households using private pit latrines. All samples were analyzed for E. coli and enterococci. A subset was analyzed for enterovirus, rotavirus, norovirus GI, norovirus GII, diarrheagenic E. coli, and general and human-specific Bacteroidales fecal markers using molecular methods. Soil collected from the house floor had significantly higher concentrations of E. coli and enterococci than soil collected from the latrine floor. There was no significant difference in fecal indicator bacteria levels between households using pit latrines with a concrete slab (improved sanitation) versus those without a slab. These findings imply that the presence of a concrete slab does not affect the level of fecal contamination in the household environment in this setting. Human Bacteroidales, pathogenic E. coli, enterovirus, and rotavirus genes were detected in soil samples, suggesting that soil should be given more attention as a transmission pathway of diarrheal illness in low-income countries.

Community Participation and Water Supply Sustainability Evidence from Handpump Projects in Rural Ghana

We investigate the extent to which different forms of community participation explain variation in handpump sustainability using data collected from 200 rural communities in Ghana. Data sources include household surveys, engineering assessments of water points, and interviews with water committees and village leaders. The depth of community members’ involvement in project planning is positively associated with handpump sustainability, whereas the breadth of community participation is not. All else held constant, handpump sustainability is enhanced by household members’ involvement in management-related decisions, but is compromised when households are responsible for technical decisions.

Fecal indicator bacteria contamination of fomites and household demand for surface disinfection products: a case study from Peru.

Surface-mediated disease transmission is understudied in developing countries, particularly in light of the evidence that surface concentrations of fecal bacteria typically exceed concentrations in developed countries by 10- to 100-fold. In this study, we examined fecal indicator bacterial contamination of dinner plates at 21 households in four peri-urban communities in the Peruvian Amazon. We also used surveys to estimate household use of and demand for surface disinfectants at 280 households. Despite detecting total coliform, enterococci, and Escherichia coli on 86%, 43%, and 24% of plates sampled, respectively, less than one-third of households were regularly using bleach to disinfect surfaces. Among non-users of bleach, only 3.2% of respondents reported a new demand for bleach, defined as a high likelihood of using bleach within the next year. This study highlights the potential for marketing approaches to increase use of and demand for surface disinfectants to improve domestic hygiene.

Using Geographic Information Systems and Spatial Analysis Methods to Assess Household Water Access and Sanitation Coverage in the SHINE Trial

Access to water and sanitation are important determinants of behavioral responses to hygiene and sanitation interventions. We estimated cluster-specific water access and sanitation coverage to inform a constrained randomization technique in the SHINE trial. Technicians and engineers inspected all public access water sources to ascertain seasonality, function, and geospatial coordinates. Households and water sources were mapped using open-source geospatial software. The distance from each household to the nearest perennial, functional, protected water source was calculated, and for each cluster, the median distance and the proportion of households within <500 m and >1500 m of such a water source. Cluster-specific sanitation coverage was ascertained using a random sample of 13 households per cluster. These parameters were included as covariates in randomization to optimize balance in water and sanitation access across treatment arms at the start of the trial. The observed high variability between clusters in both parameters suggests that constraining on these factors was needed to reduce risk of bias.

Socio-environmental drivers of sustainable adoption of household water treatment in developing countries

Household water treatment (HWT) can effectively reduce exposure to unsafe drinking water at home. Understanding the characteristics of target groups who successfully adopt HWT, such as perception about water quality and usefulness of HWT, income, or parental education, is essential for enhancing the adoption of HWT in developing countries. The objective of this study is to analyze the interactions between such socio-environmental characteristics, rather than a single characteristic, in order to explain the adoption of HWT. Five socio-environmental characteristics and behavior determinants were analyzed using Qualitative Comparative Analysis (QCA) from 41 case studies in Africa, Asia, and South America. Results show that there is no single characteristic that alone explains the adoption of HWT. QCA identified five pathways leading to high adoption of HWT. Perceived threat due to bad water quality is a pre-condition for three of the pathways. However, perceived threat does not alone explain adoption of HWT and must be accompanied by other conditions. Households connected to piped water schemes can also be potential HWT adopters as long as they perceive poor tap water quality. Finally, households who are able to afford the full cost of HWT tend to adopt it only when they neither have prior experience with HWT nor a connection to a piped scheme. Our findings therefore highlight the necessity to analyze interactions between socio-environmental characteristics of households and behavior determinants in order to determine the adoption of HWT.Household water treatment: understanding usageHousehold water treatments (HWT)—such as boiling, chlorination and filtration—are proven approaches to ensure access to drinking water in areas that do not have access to a centralized safe water supply, such as in developing countries. However, several socio-environmental factors are known to affect the adoption of HWT, including education level and local culture influencing a person’s willingness and ability to pay for HWT. A team led by Luuk Rietveld from TU Delft in the Netherlands now finds that no single socio-environmental characteristic influences HWT uptake and, instead, an interplay exists between multiple factors. It is found that adoption of HWT is greatest when no existing treatment facilities are available, and that the perceived risk of water being dangerous to drink is an important factor in HWT uptake.

Why do water quality monitoring programs succeed or fail? A qualitative comparative analysis of regulated testing systems in sub-Saharan Africa

Background Water quality testing is critical for guiding water safety management and ensuring public health. In many settings, however, water suppliers and surveillance agencies do not meet regulatory requirements for testing frequencies. This study examines the conditions that promote successful water quality monitoring in Africa, with the goal of providing evidence for strengthening regulated water quality testing programs. Methods and findings We compared monitoring programs among 26 regulated water suppliers and surveillance agencies across six African countries. These institutions submitted monthly water quality testing results over 18 months. We also collected qualitative data on the conditions that influenced testing performance via approximately 821 h of semi-structured interviews and observations. Based on our qualitative data, we developed the Water Capacity Rating Diagnostic (WaterCaRD) to establish a scoring framework for evaluating the effects of the following conditions on testing performance: accountability, staffing, program structure, finances, and equipment & services. We summarized the qualitative data into case studies for each of the 26 institutions and then used the case studies to score the institutions against the conditions captured in WaterCaRD. Subsequently, we applied fuzzy-set Qualitative Comparative Analysis (fsQCA) to compare these scores against performance outcomes for water quality testing. We defined the performance outcomes as the proportion of testing Targets Achieved (outcome 1) and Testing Consistency (outcome 2) based on the monthly number of microbial water quality tests conducted by each institution. Our analysis identified motivation & leadership, knowledge, staff retention, and transport as institutional conditions that were necessary for achieving monitoring targets. In addition, equipment, procurement, infrastructure, and enforcement contributed to the pathways that resulted in strong monitoring performance. Conclusions Our identification of institutional commitment, comprising motivation & leadership, knowledge, and staff retention, as a key driver of monitoring performance was not surprising: in weak regulatory environments, individuals and their motivations take-on greater importance in determining institutional and programmatic outcomes. Nevertheless, efforts to build data collection capacity in low-resource settings largely focus on supply-side interventions: the provision of infrastructure, equipment, and training sessions. Our results indicate that these interventions will continue to have limited long-term impacts and sustainability without complementary strategies for motivating or incentivizing water supply and surveillance agency managers to achieve testing goals. More broadly, our research demonstrates both an experimental approach for diagnosing the systems that underlie service provision and an analytical strategy for identifying appropriate interventions.

Assessing the Impact of a Risk-Based Intervention on Piped Water Quality in Rural Communities: The Case of Mid-Western Nepal

Ensuring universal access to safe drinking water is a global challenge, especially in rural areas. This research aimed to assess the effectiveness of a risk-based strategy to improve drinking water safety for five gravity-fed piped schemes in rural communities of the Mid-Western Region of Nepal. The strategy was based on establishing community-led monitoring of the microbial water quality and the sanitary status of the schemes. The interventions examined included field-robust laboratories, centralized data management, targeted infrastructure improvements, household hygiene and filter promotion, and community training. The results indicate a statistically significant improvement in the microbial water quality eight months after intervention implementation, with the share of taps and household stored water containers meeting the international guidelines increasing from 7% to 50% and from 17% to 53%, respectively. At the study endline, all taps had a concentration of <10 CFU Escherichia coli/100 mL. These water quality improvements were driven by scheme-level chlorination, improved hygiene behavior, and the universal uptake of household water treatment. Sanitary inspection tools did not predict microbial water quality and, alone, are not sufficient for decision making. Implementation of this risk-based water safety strategy in remote rural communities can support efforts towards achieving universal water safety.

Water supply in rural communities

In this chapter we present an exchange systems approach to evaluate the potential of water markets to provide sustainable and equitable access for all. The approach is sourced from marketing theory, which in turn is constructed on a social exchange and general systems theory platform (Bagozzi, 1978; Layton, 2007). The exchange systems concept offers a systemic view of exchange that allows for the integration of broader economic and social considerations into the design of water markets. We illustrate different types of exchange systems to offer the reader a broader perspective on water markets. Such a perspective can enable new thinking in how water provision systems can contribute to improved human health. We begin with a general introduction to the marketing exchange concept and subsequently trace its evolution to exchange systems.