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1.
Environ Sci Technol ; 56(19): 13985-13995, 2022 10 04.
Artigo em Inglês | MEDLINE | ID: mdl-36125807

RESUMO

Over 2 billion people globally lack access to safely managed drinking water. In contrast to the household-level, manually implemented treatment products that have been the dominant strategy for gaining low-cost access to safe drinking water, passive chlorination technologies have the potential to treat water and reduce reliance on individual behavior change. However, few studies exist that evaluate the performance and costs of these technologies over time, especially in small, rural systems. We conducted a nonrandomized evaluation of two passive chlorination technologies for system-level water treatment in six gravity-fed, piped water systems in small communities in the hilly region of western Nepal. We monitored water quality indicators upstream of the treatment, at shared taps, and at households, as well as user acceptability and maintenance costs, over 1 year. At baseline, over 80% of tap samples were contaminated with Escherichia coli. After 1 year of system-level chlorination, only 7% of those same taps had E. coli. However, 29% of household stored water was positive for E. coli. Per cubic meter of treated water, the cost of chlorine was 0.06-0.09 USD, similar to the cost of monitoring technology installations. Safe storage, service delivery models, and reliable supply chains are required, but passive chlorination technologies have the potential to radically improve how rural households gain access to safely managed water.


Assuntos
Água Potável , Purificação da Água , Cloro , Escherichia coli , Halogenação , Humanos , Nepal , Microbiologia da Água , Qualidade da Água , Abastecimento de Água
2.
BMC Public Health ; 20(1): 1241, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32799826

RESUMO

BACKGROUND: Providing universal access to safe water, sanitation and hygiene (WASH) in remote Nepal remains challenging. We investigated WASH conditions and their association with children's nutritional status, intestinal parasitic infections and diarrhoea. METHODS: Data was collected through a cross-sectional survey of 1427 households, including questionnaires, observations, stool analysis, anthropometry, water quality measurements, and assessment of clinical signs of nutritional deficiencies. RESULTS: We found 55.5% of children were undernourished, 63.9% had clinical signs of nutritional deficiencies, 51.1% had intestinal parasitic infections and 52.2% had diarrhoea. Multivariate mixed logistic regression analysis revealed a statistically significant negative association between undernutrition and socio-economic level, with adjusted odds ratios (AOR) of 0.70 (95%-CI = 0.43-1.11) and 0.43 (95%-CI = 0.25-0.75) for high and intermediate levels compared to the lowest level. Undernutrition was negatively associated with regular deworming of children (AOR = 0.44, 95% CI = 0.20-0.94), food supplements (AOR = 0.57, 95% CI = 0.38-0.84), household's own food production (AOR = 0.67, 95% CI = 0.46-0.97) and personal hygiene (AOR = 0.83, 95% CI = 0.51-1.35). Nutritional deficiency was negatively associated with handwashing after cleaning a baby's bottom (AOR = 0.60, 95% CI = 0.40-0.92) and cleanliness of caregiver's hands (AOR = 0.61, 95% CI = 0.41-0.89) and positively associated with keeping animals inside the house overnight (AOR = 1.71, 95% CI = 1.17-2.51) and the presence of total coliforms in the drinking water source (AOR = 10.44, 95% CI = 1.61-67.4). Diarrhoea was positively associated with intermittent water supply (AOR = 2.72, 95% CI = 1.18-6.31) and the presence of a mud floor (AOR = 2.29, 95% CI = 1.20-4.37) and negatively associated with cleanliness of the toilet (AOR = 0.68, 95% CI = 0.47-0.98), and the cleanliness of children's hands (AOR = 0.62, 95% CI = 0.40-0.96). CONCLUSIONS: Our study found, more than half of the survey children were in a critical health condition. Results suggest that child health improvements are dependent on multiple public health improvements, including providing better nutrition, promoting adequate hygiene behaviour, such as handwashing, keeping the latrines clean, keeping the household environment free from animal faeces and assuring a reliable supply of safe water.


Assuntos
Diarreia/epidemiologia , Higiene , Enteropatias Parasitárias/epidemiologia , Estado Nutricional , Saúde da População Rural/estatística & dados numéricos , Saneamento/estatística & dados numéricos , Abastecimento de Água/estatística & dados numéricos , Adulto , Cuidadores/estatística & dados numéricos , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Nepal/epidemiologia
3.
Environ Sci Technol ; 53(5): 2852-2861, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30689351

RESUMO

Sustainable Development Goal (SDG) Indicator 6.2.1 requires household handwashing facilities to have soap and water, but there are no guidelines for handwashing water quality. In contrast, drinking water quality guidelines are defined: water must be "free from contamination" to be defined as "safely managed" (SDG Indicator 6.1.1). We modeled the hypothesized mechanism of infection due to contaminated handwashing water to inform risk-based guidelines for microbial quality of handwashing water. We defined two scenarios that should not occur: (1) if handwashing caused fecal contamination, indicated using Escherichia coli, on a person's hands to increase rather than decrease and (2) if hand-to-mouth contacts following handwashing caused an infection risk greater than an acceptable threshold. We found water containing <1000 E. coli colony-forming units (CFU) per 100 mL removes E. coli from hands with>99.9% probability. However, for the annual probability of infection to be <1:1000, handwashing water must contain <2 × 10-6 focus-forming units of rotavirus, <1 × 10-4 CFU of Vibrio cholerae, and <9 × 10-6 Cryptosporidium oocysts per 100 mL. Our model suggests that handwashing with nonpotable water will generally reduce fecal contamination on hands but may be unable to lower the annual probability of infection risks from hand-to-mouth contacts below 1:1000.


Assuntos
Desinfecção das Mãos , Qualidade da Água , Escherichia coli , Higiene , Sabões
4.
Clin Infect Dis ; 61 Suppl 7: S716-25, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26602299

RESUMO

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.


Assuntos
Sistemas de Informação Geográfica , Saneamento , Análise Espacial , Abastecimento de Água , Características da Família , Feminino , Humanos , Lactente , Masculino , População Rural , Zimbábue
5.
Environ Sci Technol ; 46(11): 5736-43, 2012 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-22545817

RESUMO

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.


Assuntos
Diarreia/microbiologia , Monitoramento Ambiental , Características da Família , Fezes/microbiologia , Saneamento , Microbiologia do Solo , Contagem de Colônia Microbiana , Produtos Agrícolas/microbiologia , Enterococcus/crescimento & desenvolvimento , Escherichia coli/genética , Escherichia coli/crescimento & desenvolvimento , Genes Bacterianos/genética , Humanos , Análise de Sequência de DNA , Propriedades de Superfície , Tanzânia
6.
Artigo em Inglês | MEDLINE | ID: mdl-32218157

RESUMO

Accurate assessments of drinking water quality, household hygenic practices, and the mindset of the consumers are critical for developing effective water intervention strategies. This paper presents a microbial quality assessment of 512 samples from household water storage containers and 167 samples from points of collection (POC) in remote rural communities in the hilly area of western Nepal. We found that 81% of the stored drinking water samples (mean log10 of all samples = 1.16 colony-forming units (CFU)/100 mL, standard deviation (SD) = 0.84) and 68% of the POC samples (mean log10 of all samples = 0.57 CFU/100 mL, SD = 0.86) had detectable E. coli. The quality of stored water was significantly correlated with the quality at the POC, with the majority (63%) of paired samples showing a deterioration in quality post-collection. Locally applied household water treatment (HWT) methods did not effectively improve microbial water quality. Among all household sanitary inspection questions, only the presence of livestock near the water storage container was significantly correlated with its microbial contamination. Households' perceptions of their drinking water quality were mostly influenced by the water's visual appearance, and these perceptions in general motivated their use of HWT. Improving water quality within the distribution network and promoting safer water handling practices are proposed to reduce the health risk due to consumption of contaminated water in this setting.


Assuntos
Água Potável , Purificação da Água , Qualidade da Água , Escherichia coli , Humanos , Nepal , População Rural , Microbiologia da Água , Abastecimento de Água
7.
Nat Microbiol ; 5(6): 787-795, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32467623

RESUMO

Antimicrobial resistance (AMR) is a growing public health challenge that is expected to disproportionately burden lower- and middle-income countries (LMICs) in the coming decades. Although the contributions of human and veterinary antibiotic misuse to this crisis are well-recognized, environmental transmission (via water, soil or food contaminated with human and animal faeces) has been given less attention as a global driver of AMR, especially in urban informal settlements in LMICs-commonly known as 'shanty towns' or 'slums'. These settlements may be unique hotspots for environmental AMR transmission given: (1) the high density of humans, livestock and vermin living in close proximity; (2) frequent antibiotic misuse; and (3) insufficient drinking water, drainage and sanitation infrastructure. Here, we highlight the need for strategies to disrupt environmental AMR transmission in urban informal settlements. We propose that water and waste infrastructure improvements tailored to these settings should be evaluated for their effectiveness in limiting environmental AMR dissemination, lowering the community-level burden of antimicrobial-resistant infections and preventing antibiotic misuse. We also suggest that additional research is directed towards developing economic and legal incentives for evaluating and implementing water and waste infrastructure in these settings. Given that almost 90% of urban population growth will occur in regions predicted to be most burdened by the AMR crisis, there is an urgent need to build effective, evidence-based policies that could influence massive investments in the built urban environment in LMICs over the next few decades.


Assuntos
Anti-Infecciosos/farmacologia , Doenças Transmissíveis/epidemiologia , Doenças Transmissíveis/transmissão , Resistência Microbiana a Medicamentos , Exposição Ambiental , Saúde da População Urbana , Reforma Urbana , Doenças Transmissíveis/tratamento farmacológico , Doenças Transmissíveis/microbiologia , Meio Ambiente , Humanos , Saneamento , Águas Residuárias
8.
Artigo em Inglês | MEDLINE | ID: mdl-31652957

RESUMO

Uganda was among the first countries in Africa that pioneered Water Safety Plan (WSP) development and implementation, with the first WSP dating back to 2002. The objective of this study was to assess WSP status in Uganda, focusing on the experience of the National Water and Sewerage Corporation (NWSC), in order to understand the factors that influenced it and strategies for scaling-up. This study consisted of a review of documentation for 20 WSPs, 42 interviews, a focus group discussion and four field visits. Results show that the development of the 20 WSPs over the last 15 years was largely incomplete and diverse. Most of the WSPs focused on system assessment and improvement, but failed to include WSP monitoring, verification and management. The monitoring of control measures was implemented in nine of the 20 systems, while verification took place in the form of internal (5/20) and external (2/20) auditing. The main barriers identified to WSP implementation were inadequate training, team composition and deployment, mistaken perception and inability to evaluate WSP effectiveness. Conversely, the main enabling factors were management commitment, public health responsibility, good customer relations, financial availability and reliable laboratories. These findings suggest a need for more institutionalization of WSPs with improved coordination across stakeholder groups.


Assuntos
Água Potável/normas , Guias como Assunto , Saúde Pública/normas , Gestão da Segurança/normas , Abastecimento de Água/normas , Humanos , Uganda
9.
Int J Hyg Environ Health ; 222(5): 847-855, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31047815

RESUMO

About 20 Million (73%) people in Nepal still do not have access to safely managed drinking water service and 22 million (79%) do not treat their drinking water before consumption. Few studies have addressed the combination of socio-economic characteristics and psychosocial factors that explain such behaviour in a probabilistic manner. In this paper we present a novel approach to assess the usage of household water treatment (HWT), using data from 451 households in mid and far-western rural Nepal. We developed a Bayesian belief network model that integrates socio-economic characteristics and five psychosocial factors. The socio-economic characteristics of households included presence of young children, having been exposed to HWT promotion in the past, level of education, type of water source used, access to technology and wealth level. The five psychosocial factors capture households' perceptions of incidence and severity of water-borne infections, attitudes towards the impact of poor water quality on health, water treatment norms and the knowledge level for performing HWT. We found that the adoption of technology was influenced by the psychosocial factors norms, followed by the knowledge level for operating the technology. Education, wealth level, and being exposed to the promotion of HWT were the most influential socio-economic characteristics. Interestingly, households who were connected to a piped water scheme have a higher probability of HWT adoption compared to other types of water sources. The scenario analysis revealed that interventions that only target single socio-economic characteristics do not effectively boost the probability of HWT practice. However, interventions addressing several socio-economic characteristics increase the probability of HWT adoption among the target groups.


Assuntos
Purificação da Água/métodos , Teorema de Bayes , Comportamento , Estudos Transversais , Características da Família , Humanos , Nepal , Psicologia , Fatores Socioeconômicos , Microbiologia da Água , Abastecimento de Água
10.
J Vis Exp ; (145)2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30958456

RESUMO

Incubators are essential for a range of culture-based microbial methods, such as membrane filtration followed by cultivation for assessing drinking water quality. However, commercially available incubators are often costly, difficult to transport, not flexible in terms of volume, and/or poorly adapted to local field conditions where access to electricity is unreliable. The purpose of this study was to develop an adaptable, low-cost and transportable incubator that can be constructed using readily available components. The electronic core of the incubator was first developed. These components were then tested under a range of ambient temperature conditions (3.5 °C - 39 °C) using three types of incubator shells (polystyrene foam box, hard cooler box, and cardboard box covered with a survival blanket). The electronic core showed comparable performance to a standard laboratory incubator in terms of the time required to reach the set temperature, inner temperature stability and spatial dispersion, power consumption, and microbial growth. The incubator set-ups were also effective at moderate and low ambient temperatures (between 3.5 °C and 27 °C), and at high temperatures (39 °C) when the incubator set temperature was higher. This incubator prototype is low-cost (< 300 USD) and adaptable to a variety of materials and volumes. Its demountable structure makes it easy to transport. It can be used in both established laboratories with grid power or in remote settings powered by solar energy or a car battery. It is particularly useful as an equipment option for field laboratories in areas with limited access to resources for water quality monitoring.


Assuntos
Custos e Análise de Custo , Incubadoras/economia , Laboratórios , Eletricidade , Temperatura , Fatores de Tempo
11.
Artigo em Inglês | MEDLINE | ID: mdl-30065180

RESUMO

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.


Assuntos
Água Potável/normas , Guias como Assunto , Medição de Risco/normas , Microbiologia da Água/normas , Purificação da Água/normas , Qualidade da Água/normas , Abastecimento de Água/normas , Humanos , Nepal , População Rural
12.
Int J Hyg Environ Health ; 221(6): 907-920, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29861398

RESUMO

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.


Assuntos
Monitoramento Ambiental/legislação & jurisprudência , Qualidade da Água , Abastecimento de Água/legislação & jurisprudência , África Subsaariana , Regulamentação Governamental , Humanos , Liderança , Motivação , Inquéritos e Questionários , Poluição da Água/análise
13.
Am J Trop Med Hyg ; 89(5): 869-72, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24019431

RESUMO

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.


Assuntos
Desinfetantes/provisão & distribuição , Desinfecção/estatística & dados numéricos , Fômites/microbiologia , Higiene/educação , Enterobacteriaceae , Enterococcus , Escherichia coli , Características da Família , Fezes/microbiologia , Humanos , Peru
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