BEYOND DIARRHEA: FECAL-ORAL PATHOGEN TRANSMISSION AND ENVIRONMENTAL ENTEROPATHY IN IQUITOS, PERU

The importance of clean water and adequate sanitation is a widely recognized characteristic of healthy communities. Across the developing world, many communities are without this vital infrastructure, thereby vulnerable to enteric infections from pathogens that travel through the environment and may cause diarrhea. Looking beyond diarrhea, a more serious, long-lasting subclinical condition called environmental enteropathy (EE) may develop in the intestinal tract from enteropathogen exposure, which permanently alters the ability of the intestine to take up nutrients and the host to fight off infections. The first manuscript of this dissertation relates water and sanitation conditions in households to child EE biomarkers in stool, urine and serum. This study found that the water and sanitation conditions were associated with fecal markers for EE in a peri-urban community of Iquitos, Peru. The results provide preliminary evidence for the hypothesis that children under 24 months of age living in unsanitary conditions will have elevated levels of fecal EE markers for gut inflammation and gut permeability that lead to stunting. The second manuscript characterizes fecal contamination on household floors, an important transmission route for fecal pathogens that may greatly affect children under 24 months of age who spend a lot of time playing and eating off the floor. This study found that households with improved sanitation and cement floors in the kitchen area had reduced fecal contamination compared to those with unimproved sanitation and dirt floors. These findings suggest that the sanitation facilities of a home may impact the microbial load found on floors, contributing to the potential for household floors to serve as an indirect route of fecal pathogen transmission to children. The third and fourth manuscripts present saliva as a novel and minimally invasive specimen for use in community based studies to assess microbial pressure and pathogen-specific infections. The outcome measure of salivary secretory immunoglobulin A was found to be associated with the sanitation and household characteristics of children living in peri-urban Iquitos, Peru and demonstrated an important proof of concept for future water and sanitation interventions that this marker can differentiate between households within a community

The relationship between household sanitation and women’s experience of menstrual hygiene: Findings from a cross-sectional survey in Kaduna State, Nigeria

Global efforts to improve sanitation have emphasized the needs of women and girls. Managing menstruation is one such need, yet there is scarce research capturing current practices. This study investigated the relationships between household sanitation and women’s experience of menstrual management. Secondary analyses were undertaken on data from 1994 women and girls collected through the Performance Monitoring and Accountability 2020 survey in Kaduna, Nigeria. In multivariable models, women had higher odds of using the main household sanitation facility for menstrual management when they had access to a basic (OR = 1.76 95%CI 1.26–2.46) or limited (OR = 1.63 95%CI 1.08–2.48) sanitation facility, compared to an unimproved facility. Women with no household sanitation facility had higher odds of using their sleeping area (OR = 3.56 95%CI 2.50–5.06) or having no facility for menstrual management (OR = 9.86 95%CI 5.76–16.87) than women with an unimproved sanitation facility. Menstrual management locations were associated with ratings of their characteristics. Safely managed or basic sanitation facilities were not rated more favorably than unimproved facilities in privacy (OR = 1.02 95%CI 0.70–1.48), safety (OR = 1.45 95%CI 0.98–2.15), access to a lock (OR = 0.93 95%CI 0.62–1.37), or soap and water (OR = 1.04 95%CI 0.70–1.56). Women using their sleeping area had more favorable perceptions of their environment. Findings suggest household sanitation influences women’s choices for menstrual management, but that existing indicators for improvement are not sensitive to menstrual needs.SCOPU

A longitudinal study of household water, sanitation, and hygiene characteristics and environmental enteropathy markers in children less than 24 months in Iquitos, Peru

Funding Information: Financial support: The MAL-ED is carried out as a collaborative project supported by the Bill & Melinda Gates Foundation, the Foundation for the National Institutes of Health, and the National Institutes of Health, Fogarty International Center. While conducting this work, Natalie Exum was supported by The NSF IGERT Grant 1069213, The Osprey Foundation of Maryland Grant 1602030014, the Johns Hopkins Water Institute, Johns Hopkins Fisher Center Discovery Program Grant 010 KOS2015, The Kazuyoshi Kawata fund in Sanitary Engineering and Science, and the Dr. C. W. Kruse Memorial Fund Scholarship. Publisher Copyright: © 2018 by The American Society of Tropical Medicine and Hygiene.Peer reviewedPublisher PD

Water quality, weather and environmental factors associated with fecal indicator organism density in beach sand at two recreational marine beaches

Recent studies showing an association between fecal indicator organisms (FIOs) in sand and gastrointestinal (GI) illness among beachgoers with sand contact have important public health implications because of the large numbers of people who recreate at beaches and engage in sand contact activities. Yet, factors that influence fecal pollution in beach sand remain unclear. During the 2007 National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study, sand samples were collected at three locations (60 m apart) on weekend days (Sat, Sun) and holidays between June and September at two marine beaches — Fairhope Beach, AL and Goddard Beach, RI — with nearby publicly-owned treatment works (POTWs) outfalls. F+ coliphage, enterococci, Bacteroidales, fecal Bacteroides spp., and Clostridium spp. were measured in sand using culture and qPCR-based calibrator-cell equivalent methods. Water samples were also collected on the same days, times and transects as the 144 sand samples and were assayed using the same FIO measurements. Weather and environmental data were collected at the time of sample collection. Mean FIO concentrations in sand varied over time, but not space. Enterococci CFU and CCE densities in sand were not correlated, although other FIOs in sand were. The strongest correlation between FIO density in sand and water was fecal Bacteroides CCE, followed by enterococci CFU, Clostridium spp. CCE, and Bacteroidales CCE. Overall, the factors associated with FIO concentrations in sand were related to the sand–water interface (i.e., sand-wetting) and included daily average densities of FIOs in water, rainfall, and wave height. Targeted monitoring that focuses on daily trends of sand FIO variability, combined with information about specific water quality, weather, and environmental factors may inform beach monitoring and management decisions to reduce microbial burdens in beach sand

Evaluating declarations of open defecation free status under the Swachh Bharat (‘Clean India’) Mission: repeated cross-sectional surveys in Rajasthan, India

The objective of this study is to investigate the open defecation trends in Rajasthan during the Swachh Bharat Mission from 2016 to 2018 and analyze the main household characteristics associated with household members to continued open defecation practices in households which had access to toilet facilities. Data cleaning and analysis files are available for reproducibility of the research using publicly available data downloadable from www.pma2020.org/

BEYOND DIARRHEA: FECAL-ORAL PATHOGEN TRANSMISSION AND ENVIRONMENTAL ENTEROPATHY IN IQUITOS, PERU

The importance of clean water and adequate sanitation is a widely recognized characteristic of healthy communities. Across the developing world, many communities are without this vital infrastructure, thereby vulnerable to enteric infections from pathogens that travel through the environment and may cause diarrhea. Looking beyond diarrhea, a more serious, long-lasting subclinical condition called environmental enteropathy (EE) may develop in the intestinal tract from enteropathogen exposure, which permanently alters the ability of the intestine to take up nutrients and the host to fight off infections. The first manuscript of this dissertation relates water and sanitation conditions in households to child EE biomarkers in stool, urine and serum. This study found that the water and sanitation conditions were associated with fecal markers for EE in a peri-urban community of Iquitos, Peru. The results provide preliminary evidence for the hypothesis that children under 24 months of age living in unsanitary conditions will have elevated levels of fecal EE markers for gut inflammation and gut permeability that lead to stunting. The second manuscript characterizes fecal contamination on household floors, an important transmission route for fecal pathogens that may greatly affect children under 24 months of age who spend a lot of time playing and eating off the floor. This study found that households with improved sanitation and cement floors in the kitchen area had reduced fecal contamination compared to those with unimproved sanitation and dirt floors. These findings suggest that the sanitation facilities of a home may impact the microbial load found on floors, contributing to the potential for household floors to serve as an indirect route of fecal pathogen transmission to children. The third and fourth manuscripts present saliva as a novel and minimally invasive specimen for use in community based studies to assess microbial pressure and pathogen-specific infections. The outcome measure of salivary secretory immunoglobulin A was found to be associated with the sanitation and household characteristics of children living in peri-urban Iquitos, Peru and demonstrated an important proof of concept for future water and sanitation interventions that this marker can differentiate between households within a community

Surface Sampling Collection and Culture Methods for Escherichia coli in Household Environments with High Fecal Contamination

Empiric quantification of environmental fecal contamination is an important step toward understanding the impact that water, sanitation, and hygiene interventions have on reducing enteric infections. There is a need to standardize the methods used for surface sampling in field studies that examine fecal contamination in low-income settings. The dry cloth method presented in this manuscript improves upon the more commonly used swabbing technique that has been shown in the literature to have a low sampling efficiency. The recovery efficiency of a dry electrostatic cloth sampling method was evaluated using Escherichia coli and then applied to household surfaces in Iquitos, Peru, where there is high fecal contamination and enteric infection. Side-by-side measurements were taken from various floor locations within a household at the same time over a three-month period to compare for consistency of quantification of E. coli bacteria. The dry cloth sampling method in the laboratory setting showed 105% (95% Confidence Interval: 98%, 113%) E. coli recovery efficiency off of the cloths. The field application demonstrated strong agreement of side-by-side results (Pearson correlation coefficient for dirt surfaces was 0.83 (p < 0.0001) and 0.91 (p < 0.0001) for cement surfaces) and moderate agreement for results between entrance and kitchen samples (Pearson (0.53, p < 0.0001) and weighted Kappa statistic (0.54, p < 0.0001)). Our findings suggest that this method can be utilized in households with high bacterial loads using either continuous (quantitative) or categorical (semi-quantitative) data. The standardization of this low-cost, dry electrostatic cloth sampling method can be used to measure differences between households in intervention and non-intervention arms of randomized trials

Use of Pathogen-Specific Antibody Biomarkers to Estimate Waterborne Infections in Population-Based Settings

Purpose of reviewThis review discusses the utility of pathogen-specific antibody biomarkers for improving estimates of the population burden of waterborne infections, assessing the fraction of infections that can be prevented by specific water treatments, and understanding transmission routes and the natural history and ecology of disease in different populations (including asymptomatic infection rates).Recent findingsWe review recent literature on the application of pathogen-specific antibody response data to estimate incidence and prevalence of acute infections and their utility to assess the contributions of waterborne transmission pathways. Advantages and technical challenges associated with the use of serum versus minimally invasive salivary antibody biomarkers in cross-sectional and prospective surveys are discussed. We highlight recent advances and challenges and outline future directions for research, development, and application of antibody-based and other immunological biomarkers of waterborne infections