159 research outputs found

    Data Gaps in Evidence-Based Research on Small Water Enterprises in Developing Countries

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    This paper assess the literature on small water enterprises -- water delivery operations that predominantly provide water at the community level. A research agenda is recommended to advance knowledge on effective SWE service

    Airborne Multidrug-Resistant Bacteria Isolated from a Concentrated Swine Feeding Operation

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    The use of nontherapeutic levels of antibiotics in swine production can select for antibiotic resistance in commensal and pathogenic bacteria in swine. As a result, retail pork products, as well as surface and groundwaters contaminated with swine waste, have been shown to be sources of human exposure to antibiotic-resistant bacteria. However, it is unclear whether the air within swine operations also serves as a source of exposure to antibiotic-resistant bacterial pathogens. To investigate this issue, we sampled the air within a concentrated swine feeding operation with an all-glass impinger. Samples were analyzed using a method for the isolation of Enterococcus. A total of 137 presumptive Enterococcus isolates were identified to species level using standard biochemical tests and analyzed for resistance to erythromycin, clindamycin, virginiamycin, tetracycline, and vancomycin using the agar dilution method. Thirty-four percent of the isolates were confirmed as Enterococcus, 32% were identified as coagulase-negative staphylococci, and 33% were identified as viridans group streptococci. Regardless of bacterial species, 98% of the isolates expressed high-level resistance to at least two antibiotics commonly used in swine production. None of the isolates were resistant to vancomycin, an antibiotic that has never been approved for use in livestock in the United States. In conclusion, high-level multidrug-resistant Enterococcus, coagulase-negative staphylococci, and viridans group streptococci were detected in the air of a concentrated swine feeding operation. These findings suggest that the inhalation of air from these facilities may serve as an exposure pathway for the transfer of multidrug-resistant bacterial pathogens from swine to humans

    The role of packaged water in meeting global targets on improved water access

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    Packaged water (as either refill, bottled, or sachet water) has become an important element of water security in many low- and middle-income countries, owing to poor reliability and lack of piped water infrastructure. However, over time and across countries, the Demographic and Health Surveys monitoring program has inconsistently classified packaged water components as either improved or unimproved. Using data collected as part of the Performance Monitoring and Accountability 2020 (PMA2020) surveys on water options in nine study geographies across eight countries, we identified five geographies where packaged water constituted one of several options for 5% or more of users. In this study, four scenarios were designed in which packaged water components were variously classified as either improved or unimproved. Unimproved water use was highest in scenarios where sachet or refill water was classified as an unimproved source. Across the four scenarios, the difference in the use of unimproved water as the main option was highest (65%) in Nigeria (Lagos). That difference increased to 78% when considering all regular options. The development of these scenarios highlights the importance of classifying a source as improved or unimproved in the overall metric that indicates progress at national and international levels.IS

    Analytic regularity for a singularly perturbed system of reaction-diffusion equations with multiple scales: proofs

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    We consider a coupled system of two singularly perturbed reaction-diffusion equations, with two small parameters 0<ϵμ10< \epsilon \le \mu \le 1, each multiplying the highest derivative in the equations. The presence of these parameters causes the solution(s) to have \emph{boundary layers} which overlap and interact, based on the relative size of ϵ\epsilon and % \mu. We construct full asymptotic expansions together with error bounds that cover the complete range 0<ϵμ10 < \epsilon \leq \mu \leq 1. For the present case of analytic input data, we derive derivative growth estimates for the terms of the asymptotic expansion that are explicit in the perturbation parameters and the expansion order

    High-risk water and sanitation practices: evidence of underreporting from eight countries

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    Water and sanitation indicators in the erstwhile Millennium Development Goals (MDGs) failed to capture high-risk practices such as unimproved water consumption and open defecation undertaken on a regular basis. In conjunction with local partners, we used a mobile platform to implement representative randomized household surveys in eight countries across Asia and Africa (n=245,054) to quantify the presence and magnitude of such underreporting. Our study identified the use of high-risk practices as a regular option to be greater than their use as the main option. Across the study areas, this consistent underreporting amounted to 26 million (unimproved water) and 50 million (open defecation) people not being targeted for suitable policy interventions. A deeper analysis of Ghana shows poor and rural households are more likely to engage in high-risk practices. Current metrics inflate water and sanitation progress, and need to be adapted for the complex world we live in

    Lower Prevalence of Antibiotic-Resistant Enterococci on U.S. Conventional Poultry Farms that Transitioned to Organic Practices

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    Background: In U.S. conventional poultry production, antimicrobials are used for therapeutic, prophylactic, and nontherapeutic purposes. Researchers have shown that this can select for antibiotic-resistant commensal and pathogenic bacteria on poultry farms and in poultry-derived products. However, no U.S. studies have investigated on-farm changes in resistance as conventional poultry farms transition to organic practices and cease using antibiotics

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

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    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

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

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    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

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

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    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
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