Microbiological effectiveness of locally produced ceramic filters for drinking water treatment in Cambodia

Low-cost options for the treatment of drinking water at the household level are being explored by the Cambodian government and non-governmental organizations (NGOs) working in Cambodia, where many lack access to improved drinking water sources and diarrhoeal diseases are the most prevalent cause of death in children under 5 years of age. The ceramic water purifier (CWP), a locally produced, low-cost ceramic filter, is now being implemented by several NGOs, and an estimated 100,000 + households in the country now use them for drinking water treatment. Two candidate filters were tested for the reduction of bacterial and viral surrogates for waterborne pathogens using representative Cambodian drinking water sources (rainwater and surface water) spiked with Escherichia coli and bacteriophage MS2. Results indicate that filters were capable of reducing key microbes in the laboratory with mean reductions of E. coli of approximately 99% and mean reduction of bacteriophages of 90–99% over >600 litres throughput. Increased effectiveness was not observed in filters with an AgNO₃ amendment. At under US$10 per filter, locally produced ceramic filters may be a promising option for drinking water treatment and safe storage at the household level.     

Child dysentery in the Limpopo Valley: a cohort study of water, sanitation and hygiene risk factors

The objective of this cohort study was to assess risk factors for child dysentery and watery diarrhoea. The study participants consisted of 254 children aged 12–24 months in rural South Africa and Zimbabwe in households where drinking water was collected from communal sources. The main outcome measure was the most severe diarrhoea episode: dysentery, watery diarrhoea or none. For dysentery, drinking water from sources other than standpipes had a relative risk ratio of 3.8 (95% CI 1.5–9.8). Poor source water quality, as indicated by Escherichia coli counts of 10 or more cfu 100 ml^-1, increased risk by 2.9 (1.5–5.7). There were no other significant risk factors for dysentery and none for watery diarrhoea. In this study, endemic dysentery is associated only with faecal contamination of source water. Sources other than standpipes, including improved groundwater, are of greater risk. Remediation of water quality by treatment at source or in the household will be required to achieve access to safe drinking water in accordance with the 7th Millennium Development Goal.     

Microbiologic effectiveness of boiling and safe water storage in South Sulawesi, Indonesia

In Indonesia, where diarrhea remains a major cause of mortality among children <5 years, the government promotes boiling of drinking water. We assessed the impact of boiling on water quality in South Sulawesi. We surveyed randomly selected households with at least one child <5 years old in two rural districts and tested source and stored water samples for Escherichia coli contamination. Among 242 households, 96% of source and 51% of stored water samples yielded E. coli. Unboiled water samples, obtained from 15% of households, were more likely to yield E. coli than boiled samples [prevalence ratios (PR) = 2.0, 95% confidence interval (CI) 1.7–2.5]. Water stored in wide-mouthed (PR = 1.4, 95% CI = 1.1–1.8) or uncovered (PR = 1.8, 95% CI = 1.3–2.4) containers, or observed to be touched by the respondent's hands (PR = 1.6, 95% CI = 1.3–2.1) was more likely to yield E. coli. A multivariable model showed that households that did not boil water were more likely to have contaminated stored water than households that did boil water (PR = 1.9, 95% CI = 1.5–2.3). Although this study demonstrated the effectiveness of boiling in reducing contamination, overall impact on water quality was suboptimal. Future studies are needed to identify factors behind the success of boiling water in Indonesia to inform efforts to scale up other effective water treatment practices.     

The effectiveness of large household water storage tanks for protecting the quality of drinking water

Many communities along the US-México border remain without infrastructure for water and sewage. Residents in these communities often collect and store their water in open 55-gallon drums. This study evaluated changes in drinking water quality resulting from an intervention that provided large closed water storage tanks (2,500-gallons) to individual homes lacking a piped water supply. After the intervention, many of the households did not change the source of their drinking water to the large storage tanks. Therefore, water quality results were first compared based on the source of the household's drinking water: store or vending machine, large tank, or collected from a public supply and transported by the household. Of the households that used the large storage tank as their drinking water supply, drinking water quality was generally of poorer quality. Fifty-four percent of samples collected prior to intervention had detectable levels of total coliforms, while 82% of samples were positive nine months after the intervention (p < 0.05). Exploratory analyses were also carried out to measure water quality at different points between collection by water delivery trucks and delivery to the household's large storage tank. Thirty percent of the samples taken immediately after water was delivered to the home had high total coliforms (>10 CFU/100 ml). Mean free chlorine levels dropped from 0.43 mg/l, where the trucks filled their tanks, to 0.20 mg/l inside the household's tank immediately after delivery. Results of this study have implications for interventions that focus on safe water treatment and storage in the home, and for guidelines regarding the level of free chlorine required in water delivered by water delivery trucks.     

Bacteriological assessment of drinking water supply options in coastal areas of Bangladesh

This study was conducted to assess the bacteriological quality of alternative drinking water supply options in southwest coastal areas of Bangladesh. A total of 90 water samples were collected during both dry and wet seasons from household based rainwater harvesting systems (RWHSs), community based rain water harvesting systems (CRWHSs), pond-sand filters (PSFs) and ponds. The samples were evaluated for faecal coliform, Escherichia coli and Heterotrophic Plate Count, as well as Vibrio cholerae, Salmonella spp., Shigella spp. and Pseudomonas spp. Physico-chemical parameters (pH, electrical conductivity, and color) were also examined. In addition, sanitary inspections were conducted to identify faecal contamination sources. All options showed varying degrees of indicator bacterial contamination. The median E. coli concentrations measured for RWHSs, CRWHSs, PSFs, and ponds were 16, 7, 11, and 488 cfu/100 ml during the wet season, respectively. Vibrio cholerae O1/O139, Salmonella and Shigella spp. were not found in any samples. However, Vibrio cholerae Non-O1/Non-O139 and Pseudomonas spp. were isolated from 74.4% and 91.1% of the water samples collected during the wet season. A maximum pH of 10.4 was found in CRWHSs. Estimation of the disease burden for all options in disability adjusted life years (DALYs) showed an increased disease burden during the wet season. According to sanitary inspections, poor maintenance and unprotected ponds were responsible for rainwater and PSF water contamination, respectively. The findings of the present study suggest that alternative drinking water supply options available in southwest coastal Bangladesh pose a substantial risk to public health.     

A post-implementation evaluation of ceramic water filters distributed to tsunami-affected communities in Sri Lanka

Sri Lanka was devastated by the 2004 Indian Ocean tsunami. During recovery, the Red Cross distributed approximately 12,000 free ceramic water filters. This cross-sectional study was an independent post-implementation assessment of 452 households that received filters, to determine the proportion still using filters, household characteristics associated with use, and quality of household drinking water. The proportion of continued users was high (76%). The most common household water sources were taps or shallow wells. The majority (82%) of users used filtered water for drinking only. Mean filter flow rate was 1.12 L/hr (0.80 L/hr for households with taps and 0.71 for those with wells). Water quality varied by source; households using tap water had source water of high microbial quality. Filters improved water quality, reducing Escherichia coli for households (largely well users) with high levels in their source water. Households were satisfied with filters and are potentially long-term users. To promote sustained use, recovery filter distribution efforts should try to identify households at greatest long-term risk, particularly those who have not moved to safer water sources during recovery. They should be joined with long-term commitment to building supply chains and local production capacity to ensure safe water access.     

Factors associated with post-treatment E. coli contamination in households practising water treatment: a study of rural Cambodia

The purpose of this study was to assess factors associated with Escherichia coli (E. coli) contamination in rural households in Cambodia that have adopted household water treatment. The following factors were significantly associated (α < 0.05) with apparent E. coli contamination: cleaning the drinking vessel with untreated water, not drying the cup (with a cloth), accessing treated water by the use of a scoop (ref: using a tap), having more than one untreated water storage container, having an untreated water storage container that appeared dirty on the outside, and cows living within 10 m of the household. This study provides further evidence confirming previous studies reporting an association between inadequate cleanliness of water storage containers and household drinking water contamination, and identifies practical recommendations statistically associated with reduced post-treatment E. coli contamination in the household setting in rural Cambodia.     

Microbial quality of water in rural communities of Trinidad.

A cross-sectional study was conducted in four rural communities of northeastern Trinidad to determine the microbial quality of water supply to households and that quality's relationship to source and storage device. Of the 167 household water samples tested, total coliforms were detected in 132 of the samples (79.0%), fecal coliforms in 102 (61.1%), and E. coli in 111 (66.5%). There were significant differences among the towns in the proportion of the samples contaminated with coliforms (P < 0.001) and E. coli (P < 0.001). Of 253 strains of E. coli studied, 4 (1.6%) were mucoid, 9 (3.6%) were hemolytic, and 37 (14.6%) were nonsorbitol fermenters. Of 69 isolates of E. coli tested, 10 (14.5%) were verocytotoxigenic. Twenty-eight (14.0%) of 200 E. coli isolates tested belonged to enteropathogenic serogroups. Standpipe, the most common water source, was utilized by 57 (34.1%) of the 167 households. Treated water (pipeborne in homes, standpipes, or truckborne) was supplied to 119 households (71.3%), while 48 households (28.7%) used water from untreated sources (rain, river/stream, or well) as their primary water supply. The type of household storage device was associated with coliform contamination. Water stored in drums, barrels, or buckets was more likely to harbor fecal coliforms (74.2% of samples) than was water stored in tanks (53.3% of samples), even after controlling for water source (P = 0.04). Compared with water from other sources, water piped into homes was significantly less likely to be contaminated with total coliforms (56.9% versus 88.8%, P < 0.001) and fecal coliforms (41.2% versus 69.8%, P < 0.01), even when the type of storage device was taken into account. However, fecal contamination was not associated with whether the water came from a treated or untreated source. We concluded that the drinking water in rural communities in Trinidad was grossly unfit for human consumption, due both to contamination of various water sources and during household water storage.     

Health gains from solar water disinfection (SODIS): evaluation of a water quality intervention in Yaounde, Cameroon

In developing countries, the burden of diarrhoea is still enormous. One way to reduce transmission of pathogens is by water quality interventions. Solar water disinfection (SODIS) is a low-cost and simple method to improve drinking water quality on household level. This paper evaluates the implementation of SODIS in slum areas of Yaoundé, Cameroon. Promoters trained 2,911 households in the use of SODIS. Two surveys with randomly selected households were conducted before (N = 2,193) and after (N = 783) the intervention. Using a questionnaire, interviewers collected information on the health status of children under five, on liquid consumption, hygiene and other issues. Prior to the intervention, diarrhoea prevalence amounted to 34.3% among children. After the intervention, it remained stable in the control group (31.8%) but dropped to 22.8% in the intervention group. Households fully complying with the intervention exhibited even less diarrhoea prevalence (18.3%) and diarrhoea risk could be reduced by 42.5%. Multivariate analyses revealed that the intervention effects are also observed when other diarrhoea risk factors, such as hygiene and cleanliness of household surroundings, are considered. According to the data, adoption of the method was associated with marital status. Findings suggest health benefits from SODIS use. Further promotional activities in low-income settings are recommended.     

Bacterial quality of drinking water stored in containers by boat households in Hue City, Vietnam

Objectives  To examine the bacterial quality of drinking water stored in containers by boat households in the river basin of Hue City, and associated factors. Methods  Ready-to-drink water stored in containers on boats was collected from 766 households. Escherichia coli (E. coli), total coliforms, and Enterobacteriaceae in the water were examined by the rehydratable dry-film plating method. Socioeconomic characteristics, water source, handling practices, and proficiency of disease prevention of individual households were assessed. Results   E. coli, over ten counts of total coliforms, and over ten counts of Enterobacteriaceae were detected in 25.7, 44.5, and 51.5% of 1-ml samples of ready-to-drink water stored in containers on the boats. Bacterial contamination of the water stored in containers by boat households was significantly associated with use of river water as a source of drinking water, non-boiling before storing containers for drinking, and limited proficiency in disease prevention regardless of the influence of socioeconomic characteristics of the households (P < 0.01, P < 0.05, P < 0.01, respectively). Conclusions  Bacterial contamination of ready-to-drink water stored by boat households was indicated. The households’ proficiency in disease prevention buffered contamination. A comprehensive health promotion program with a wide range of contents is required for the communities of boat households.     

PUMPS,GERMS AND STORAGE: THE IMPACT OF IMPROVED WATER CONTAINERS ON WATER QUALITY AND HEALTH

Applying a randomized controlled trial, we study the impact of improved water transport and storage containers on the water quality and health of poor rural households. The results indicate that improved household water infrastructure improves water quality and health outcomes in an environment where point‐of‐source water quality is good but where recontamination is widespread, leading to unsafe point‐of‐use drinking water. Moreover, usage rates of 88% after 7 months are encouraging with regard to sustainable adoption. Our estimates suggest that the provision of improved household water infrastructure could ‘keep clean water clean’ at a cost of only 5% of the costs of providing households with improved public water supply. Given the general consensus in the literature that recontamination of water from improved public sources is a severe public health problem, improved transport and storage technologies appear to be an effective low‐cost supplement to the current standard of financing public water supply for poor rural communities. Copyright © 2012 John Wiley & Sons, Ltd.     

'Hom': a simple point of use water treatment device

This study sought to explore a locally assembled ‘Hom’ point of use water treatment device by assessing aspects of its performance and possible effects of using it on compliant households and communities. The conceptual framework highlights poverty and environmental degradation as causes and consequences of one another, with ill-health caused by water-borne diseases reinforcing both to form a cycle. Whether or not the device would play a role in interrupting this cycle depends on its capabilities and acceptance, among other factors. Survey results indicated that the device is acceptable to 84% of respondents. Analysed data collected using questionnaires from 60 randomly sampled pilot device users revealed that it is useful to its users. Yield trials results led to the conclusion that one device unit could provide enough drinking water to satisfy the needs of a large representative household. Laboratory tests of water samples filtered with cartridges used for up to 10 years in the device found the water to be safe for drinking. It is concluded that the device is effective, environmentally friendly and useful to compliant households.     

Following the Water: A Controlled Study of Drinking Water Storage in Northern Coastal Ecuador

Background

To design the most appropriate interventions to improve water quality and supply, information is needed to assess water contamination in a variety of community settings, including those that rely primarily on unimproved surface sources of drinking water.

Objectives

We explored the role of initial source water conditions as well as household factors in determining household water quality, and how levels of contamination of drinking water change over time, in a rural setting in northern coastal Ecuador.

Methods

We sampled source waters concurrently with water collection by household members and followed this water over time, comparing Escherichia coli and enterococci concentrations in water stored in households with water stored under controlled conditions.

Results

We observed significant natural attenuation of indicator organisms in control containers and significant, although less pronounced, reductions of indicators between the source of drinking water and its point of use through the third day of sampling. These reductions were followed by recontamination in approximately half of the households.

Conclusions

Water quality improved after water was transferred from the source to household storage containers, but then declined because of recontamination in the home. Our experimental design allowed us to observe these dynamics by controlling for initial source water quality and following changes in water quality over time. These data, because of our controlled experimental design, may explain why recontamination has been reported in the literature as less prominent in areas or households with highly contaminated source waters. Our results also suggest that efforts to improve source water quality and sanitation remain important.     

An assessment of microbiological water quality of six water source categories in north-east Uganda

Target 7C of the Millennium Development Goals is to “halve, by 2015, the proportion of people without sustainable access to safe drinking water and basic sanitation”. However, the corresponding indicator measures the “proportion of population using an improved drinking water source”. This raises the question of whether “safe” and “improved” can be used interchangeably. This paper tests this hypothesis by comparing microbiological water quality in 346 different water sources across the District of Amuria in Uganda to each other and to defined standards, including the WHO drinking water standard of zero TTC per 100 ml, and the Ugandan national standard of 50 TTC per 100 ml. The water sources were grouped into six different categories: boreholes, protected springs, covered hand dug wells, open hand dug wells, open water and roofwater harvesting. The paper concludes that the ranking from the highest to the lowest microbiological quality water was: boreholes, protected springs and roofwater harvesting, open and covered hand dug wells, open water. It also concludes that sanitary surveys cannot be used to predict water quality precisely; however they are an essential component of the monitoring of safe water supplies.     

兰州市家庭饮用水状况的调查

目的了解兰州市家庭饮用水状况,为进一步指导家庭科学饮水及开发优质饮用水提供一定的参考依据。方法于2005年3—5月,对兰州市8个区县居民进行饮用水的选择及饮用状况问卷调查。结果共调查问卷1000份,收回有效问卷832份。调查结果显示,饮用自来水的有543户,占65.3%。饮用桶装水（矿泉水和纯净水）的家庭有248户,占29.8%,其中,饮用矿泉水的96户,占调查总数的11.5%;饮用纯净水的152户,占调查总数的18.3%。饮用深度处理水的41户,占4.9%。自来水用户最优先考虑的是饮水的“饮用方便”、“价格合理”、“水质安全”。桶装水用户最优先考虑的是饮水的“饮用方便”、“健康要求”、“口感好”。深度处理水用户最优先考虑的是饮水的“水质安全”、“口感好”、“健康要求”。桶装水用户中,高学历家庭所占比例为64.1%（159/248）,高于低学历家庭[35.9%（89/248）]。饮用自来水的家庭所占的构成比随着月收入的升高而降低。月收入〈8000元的家庭,饮用桶装水的构成比随着月收入的升高而升高;月收入≥8000元的家庭,饮用桶装水所占的构成比有所下降,而饮用深度处理水的家庭所占的构成比升高较多。兰州市饮用桶装水家庭可接受的价格为7.2元/桶。其中,矿泉水可接受的价格为7.3元/桶,略高于纯净水（7.2元/桶）。结论兰州市家庭选择的饮用水类型主要为自来水。被调查者的学历、月收入以及饮用水的价格对其选择饮用水类型具有一定的影响。     

安阳市某社区居民家庭饮用水类型调查

[目的]调查安阳市居民家庭饮用水类型,为今后开展饮用水卫生工作,指导群众科学选择饮用水提供依据.[方法]2009年7～9月对某社区居民进行饮用水类型的问卷调查.[结果]调查381户,居民饮用水类型以自来水+自动售水机构成比较高,占29.7％,选择不同类型饮用水考虑的前3个因素:饮用方便、口感好、卫生,高学历、经济状况好...     

Is fecal contamination of drinking water after collection associated with household water handling and hygiene practices? A study of urban slum households in Hyderabad, India

Water-borne illness, primarily caused by fecal contamination of drinking water, is a major health burden in the state of Andhra Pradesh, India. Currently drinking water is treated at the reservoir level and supplied on alternate days, necessitating storage in households for up to 48 hrs. We hypothesized that fecal contamination occurs principally during storage due to poor water handling. In this study we tested for coliform bacteria in water samples collected at distribution points as household storage containers were filled, and then tested containers in the same households 24–36 hours after collection. We also conducted an observational survey to make an assessment of water handling and hygiene. Ninety-two percent (47/51) of samples tested at supply points were adequately chlorinated and bacterial contamination was found in two samples with no residual chlorine. Samples collected from household storage containers showed an increase in contamination in 18/50 houses (36%). Households with contaminated stored samples did not show significant differences in demographics, water handling, hygiene practices, or sanitation. Nevertheless, the dramatic increase in contamination after collection indicates that until an uninterrupted water supply is possible, the point at which the biggest health impact can be made is at the household level.     

Faecal contamination of drinking water in a Brazilian shanty town: importance of household storage and new human faecal marker testing

Worldwide, contaminated drinking water poses a major health threat, particularly to child development. Diarrhoea represents a large part of the water-related disease burden and enteric infections have been linked to nutritional and growth shortfalls as well as long-term physical and cognitive impairment in children. Previous studies detailed the frequency of infection and the consequences for child health in a shanty town in north-east Brazil. To determine the frequency of contaminated water, we measured faecal contamination in primary drinking water samples from 231 randomly selected households. Risk for contamination was compared across source and storage types. Nearly a third of the study households (70/231: 30.3%) had contaminated drinking water; the source with the highest frequency of contamination was well water (23/24: 95.8%). For tap water, the type of storage had a significant effect on the susceptibility to contamination (c²=12.090; p=0.007). The observed pattern of contamination demonstrated the relative potential contributions of both source and storage. With evidence that supports the inclusion of source and storage in water quality surveys, this study, like others, suggests that contaminated drinking water in storage vessels may be an important factor for the documented diarrhoea disease burden in the Brazilian shanty town.     

农村家庭储水现状与风险因素研究

目的 了解农村家庭储水卫生现状及影响家庭储水水质的风险因素.方法 于2007年采用分层多阶段随机抽样方法抽取东、中、西部8个省的8个县40个乡镇,对农户的家庭储水现状进行现场调查,对存储前、后的水质进行比较分析,并采用Logistic回归对影响家庭储水水质的风险因素进行筛选.结果 有95.05%的农户采用专门的储水器盛装饮用水.储水器材质以搪瓷和塑料的居多,分别占40.53%和34.19%.取水容器材质主要以塑料制品为主,占62.31%.经过储存后饮用水中的菌落总数、总大肠菌群和耐热大肠菌群合格率明显下降,差异均有统计学意义(P＜0.05).Logistic回归分析显示,储水器周围存在污染源、外部不清洁、储水器破裂泄漏、储水器无盖或盖不严(清洁)、不经常清洗储水器、取水器皿暴露和储水时间过长是造成水中菌落总数超标的主要因素.各地居民均存在有饮用生水的情况,占60.11%,有89.11%的农户对目前的饮用水满意或基本满意.结论 农村家庭储水条件较差,是影响农村饮水安全性的主要风险因素.

Abstract：

Objective To know the present situation of household storage water quality and the influencing factors. Methods A total of 40 villages and towns in the eight counties of eight provinces in the east, middle and west of China were selected for the survey according to multilevel stratification random sampling in 2007. Water quality was tested and compared before and after storage. The logistic regression was used to screen the influencing factors. Results 95.50% of families used specially designed containers to store drinking water. Most households water storage tanks were made of enamelware and plastic,accounted for 40.53% and 34.19% respectively. Most water-fetching utensils were made of plastic, accounted for 62.31% of the total survey. Significant increase of bacteria count, total coliform,thermotolerant coliform was observed compared with the water quality of before storage (P<0.05). The logistic regression showed that the source pollution,uncleanness of the outer parts of containers,fracture or leakage of storage containers,the lidless storage container,the untight/unclean lid,seldom cleaning-up of the storage container, the exposure of fetching water utensils and overtime storage were the main risk factors which resulted in the bacteria count exceeding the standard limits. Most farmers have the habit of drinking raw water,accounted for 60.11%. 89.11% of farmers were very or partially satisfied with the drinking water quality. Conclusion The dinking water quality at household storage level is poor and there are some risk factors influencing storage drinking water quality, safe storage of household drinking water is an important issue in drinking water safety in rural areas in China.     

Bacterial indicators of risk of diarrhoeal disease from drinking-water in the Philippines

Inadequate measures of water quality have been used in many studies of the health effects associated with water supplies in developing countries. The present 1-year epidemiological-microbiological study evaluated four bacterial indicators of tropical drinking-water quality (faecal coliforms, Escherichia coli, enterococci and faecal streptococci) and their relationship to the prevalence of diarrhoeal disease in a population of 690 under-2-year-olds in Cebu, Philippines. E. coli and enterococci were better predictors than faecal coliforms of the risk of waterborne diarrhoeal disease. Methods to enumerate E. coli and enterococci were less subject to interference from the thermotolerant, non-faecal organisms that are indigenous to tropical waters. Little difference was observed between the illness rates of children drinking good quality water (less than 1 E. coli per 100 ml) and those drinking moderately contaminated water (2-100 E. coli per 100 ml). Children drinking water with greater than 1000 E. coli per 100 ml had significantly higher rates of diarrhoeal disease than those drinking less contaminated water. This threshold effect suggests that in developing countries where the quality of drinking-water is good or moderate other transmission routes of diarrhoeal disease may be more important; however, grossly contaminated water is a major source of exposure to faecal contamination and diarrhoeal pathogens.