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Many water sources in Nigeria are contaminated with pathogens. Several towns have witnessed outbreaks of enteric diseases due to poor hygienic standards of available drinking water. This research was undertaken to determine the spatiotemporal trends of waterborne diseases (WBDs) in Enugu, Nigeria using retrospective records from January 2013 to December 2016. A total of 18,495 individual reported cases of WBDs were analysed. The analysis showed an increasing temporal trend from 2013 to 2015, with a slight decrease in 2016. Typhoid fever had the highest frequency (48.9%) followed by diarrhoea (40%) and then dysentery (11.1%). The highest (88.9%) incidence of waterborne diseases per 10,000 peoples was from Enugu North followed by Enugu South (62.6%) and least was Enugu East (44.4%). Highest occurrence of typhoid fever and dysentery per 10,000 peoples was also found in Enugu North while Enugu East had the highest occurrence of diarrhoea in the four-yeartrends. WBDs were highest between January and March and least in July. The months with peak occurrence of WBDs falls within the dry season. The importance of having drinking water in both quality and quantity cannot be overestimated as portrayed in this study. Drinking water quality in Enugu urban is very poor especially during the dry season. This suggests a need for setting up a modality to tackle challenges of limited water supply during the dry seasons of the year and to educate the populace on household water treatment and storage method
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RESUMO Apresentam-se e discutem-se neste trabalho os resultados do monitoramento de esporos de bactérias aeróbias em uma estação de tratamento de água de ciclo completo em escala real. Os esporos foram removidos de forma consistente e efetiva ao longo das etapas do tratamento, somando cerca de 3 log em média no ciclo completo. A etapa de clarificação da água (decantação e filtração) foi a principal responsável pela remoção de esporos: 0,65 log na decantação e 1,71 log na filtração, em valores médios. Os esporos mostraram-se resistentes à cloração, mas ainda assim foi alcançada inativação média de 0,8 log. Infere-se que esporos de bactérias aeróbias são bons indicadores da eficiência do tratamento da água em ciclo completo (clarificação e desinfecção por cloração) e exibem potencial de uso como indicadores da remoção/inativação (clarificação e desinfecção por cloração) de cistos de Giardia e de remoção por clarificação de oocistos de Cryptosporidium.
ABSTRACT The results of monitoring aerobic spore-forming bacteria in a field-scale conventional water treatment plant are presented and discussed herein. Spores were consistently and effectively removed throughout the treatment steps, totaling approximately 3 log-unit complete removal. The clarification steps (sedimentation + filtration) accounted for most of the spore removal: 0.65 log by sedimentation and 1.71 log by filtration - average values. Although the spores proved to be rather resistant to chlorination, a 0.8 log-unit reduction by inactivation was achieved. It is suggested that spores of aerobic spore-forming bacteria are useful indicators for evaluating overall water treatment plant performance (clarification and disinfection by chlorination), and can potentially be used as removal/inactivation indicators (clarification and disinfection by chlorination) of Giardia cysts, and removal by clarification of Cryptosporidium oocysts.
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Background: A major health consequence of rapid population growth in urban areas is the increased pressure on existing overstretched water and sanitation services. This study of an expanding periurban neighbourhood of Yangon Region, Myanmar, aimed to ascertain the prevalence of acute diarrhoea in children under 5 years; to identify household sources of drinking-water; to describe purification and storage practices; and to assess drinking-water contamination at point-of-use. Methods: A survey of the prevalence of acute diarrhoea in children under 5 years was done in 211 households in February 2013; demographic data were also collected, along with data and details of sources of drinking water, water purification, storage practices and waste disposal. During March–August, a subset of 112 households was revisited to collect drinking water samples. The samples were analysed by the multiple tube fermentation method to count thermotolerant (faecal) coliforms and there was a qualitative determination of the presence of Escherichia coli. Results: Acute diarrhoea in children under 5 years was reported in 4.74% (10/211, 95% CI: 3.0–9.0) of households within the past two weeks. More than half of the households used insanitary pit latrines and 36% disposed of their waste into nearby streams and ponds. Improved sources of drinking water were used, mainly the unchlorinated ward reservoir, a chlorinated tube well or purified bottled water. Nearly a quarter of households never used any method for drinking-water purification. Ninety-four per cent (105/112) of water samples were contaminated with thermotolerant (faecal) coliforms, ranging from 2.2 colony-forming units (CFU)/100 mL (21.4%) to more than 1000 CFU/100 mL (60.7%). Of faecal (thermotolerant)-coliform-positive water samples, 70% (47/68) grew E. coli. Conclusion: The prevalence of acute diarrhoea reported for children under 5 years was high and a high level of drinking-water contamination was detected, though it was unclear whether this was due to contamination at source or at point-of-use. Maintenance of drinking-water quality in study households is complex. Further research is crucial to prove the cost effectiveness in quality improvement of drinking water at point-of-use in resource-limited settings. In addition, empowerment of householders to use measures of treating water by boiling, filtration or chlorination, and safe storage with proper handling is essential.
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The aim of this study was to detect arsenic concentrations in feed, well-water for drinking, eggs, and excreta of laying hens in arsenic-prone areas of Bangladesh and to assess the effect of arsenic-containing feed and well-water on the accumulation of arsenic in eggs and excreta of the same subject. One egg from each laying hen (n=248) and its excreta, feed, and well-water for drinking were collected. Total arsenic concentrations were determined by atomic absorption spectrophotometer, coupled with hydride generator. Effects of arsenic-containing feed and drinking-water on the accumulation of arsenic in eggs and excreta were analyzed by multivariate regression model, using Stata software. Mean arsenic concentrations in drinkingwater, feed (dry weight [DW]), egg (wet weight [WW]), and excreta (DW) of hens were 77.3, 176.6, 19.2, and 1,439.9 ppb respectively. Significant (p<0.01) positive correlations were found between the arsenic contents in eggs and drinking-water (r=0.602), drinking-water and excreta (r=0.716), feed and excreta (r=0.402) as well as between the arsenic content in eggs and the age of the layer (r=0.243). On an average, 55% and 82% of the total variation in arsenic contents of eggs and excreta respectively could be attributed to the variation in the geographic area, age, feed type, and arsenic contents of drinking-water and feed. For each week’s increase in age of hens, arsenic content in eggs increased by 0.94%. For every 1% elevation of arsenic in drinking-water, arsenic in eggs and excreta increased by 0.41% and 0.44% respectively whereas for a 1% rise of arsenic in feed, arsenic in eggs and excreta increased by 0.40% and 0.52% respectively. These results provide evidence that, although high arsenic level prevails in well-water for drinking in Bangladesh, the arsenic shows low biological transmission capability from body to eggs and, thus, the value was below the maximum tolerable limit for humans. However, arsenic in drinking-water and/or feed makes a significant contribution to the arsenic accumulations in eggs and excreta of laying hens.
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Diarrhoea is a hallmark of HIV infections in developing countries, and many diarrhoea-causing agents are often transmitted through water. The objective of the study was to determine the diversity and antibiotic susceptibility profiles of bacterial organisms isolated from samples of household drinking-water consumed by HIV-infected and AIDS patients. In the present study, household water stored for use by HIV-positive patients was tested for microbial quality, and isolated bacterial organisms were analyzed for their susceptibility profiles against 25 different antibiotics. The microbial quality of water was generally poor, and about 58% of water samples (n=270) were contaminated with faecal coliforms, with counts varying from 2 colony-forming unit (CFU)/100 mL to 2.4x104 CFU/100 mL. Values of total coliform counts ranged from 17 CFU/100 mL to 7.9x105/100 mL. In total, 37 different bacterial species were isolated, and the major isolates included Acinetobacter lwoffii (7.5%), Enterobacter cloacae (7.5%), Shigella spp. (14.2%), Yersinia enterocolitica (6.7%), and Pseudomonas spp. (16.3%). No Vibrio cholerae could be isolated; however, V. fluvialis was isolated from three water samples. The isolated organisms were highly resistant to cefazolin (83.5%), cefoxitin (69.2%), ampicillin (66.4%), and cefuroxime (66.2%). Intermediate resistance was observed against gentamicin (10.6%), cefepime (13.4%), ceftriaxone (27.6%), and cefotaxime (29.9%). Levofloxacin (0.7%), ceftazidime (2.2%), meropenem (3%), and ciprofloxacin (3.7%) were the most active antibiotics against all the microorganisms, with all recording less than 5% resistance. Multiple drug resistance was very common, and 78% of the organisms were resistant to three or more antibiotics. Education on treatment of household water is advised for HIV-positive patients, and measures should be taken to improve point-of-use water treatment as immunosuppressed individuals would be more susceptible to opportunistic infections.
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Microbially-unsafe water is still a major concern in most developing countries. Although many water-purification methods exist, these are expensive and beyond the reach of many people, especially in rural areas. Ayurveda recommends the use of copper for storing drinking-water. Therefore, the objective of this study was to evaluate the effect of copper pot on microbially-contaminated drinking-water. The antibacterial effect of copper pot against important diarrhoeagenic bacteria, including Vibrio cholerae O1, Shigella flexneri 2a, enterotoxigenic Escherichia coli, enteropathogenic E. coli, Salmonella enterica Typhi, and Salmonella Paratyphi is reported. When drinking-water (pH 7.83±0.4; source: ground) was contaminated with 500 CFU/mL of the above bacteria and stored in copper pots for 16 hours at room temperature, no bacteria could be recovered on the culture medium. Recovery failed even after resuscitation in enrichment broth, followed by plating on selective media, indicating loss of culturability. This is the first report on the effect of copper on S. flexneri 2a, enteropathogenic E. coli, and Salmonella Paratyphi. After 16 hours, there was a slight increase in the pH of water from 7.83 to 7.93 in the copper pots while the other physicochemical parameters remained unchanged. Copper content (177±16 ppb) in water stored in copper pots was well within the permissible limits of the World Health Organization. Copper holds promise as a point-of-use solution for microbial purification of drinking-water, especially in developing countries.
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Although many African countries, along the equator, receive a great amount of rainfall and possess a dense hydrographic network, access to drinking-water remains a great challenge. In many households, water is used for various purposes, including domestic and crafts activities. According to the World Health Organization, an estimated four billion cases of diarrheoa occurs worldwide, of which 88% are ascribed to unsafe drinking-water. This study aimed at evaluating health risks in the usage of contaminated drinking-water and its relationship with the prevalence of diarrhoeal diseases in Yaoundé, Cameroon. In this cross-sectional epidemiological design, 3,034 households with children aged less than five years were investigated. Households were selected from among 20 representative neighbourhoods out of 105 that made up the city. The study revealed a diarrheoa prevalence of 14.4% (437 diarrheoa cases out of 3,034 children tested). Among various risk factors examined, water-supply modes and quality of drinking-water were statistically associated with diarrheoa cases. Moreover, levels of diarrheoa attacks varied considerably from one neighbourhood to the other. The spatial analysis helped determine neighbourhoods of higher and lower prevalence of diarrheoa in the city.
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In-house contamination of drinking-water is a persistent problem in developing countries. This study aimed at identifying critical points of contamination and determining the extent of recontamination after water treatment. In total, 81 households were visited, and 347 water samples from their current sources of water, transport vessels, treated water, and drinking vessels were analyzed. The quality of water was assessed using Escherichia coli as an indicator for faecal contamination. The concentration of E. coli increased significantly from the water source [median=0 colony-forming unit (CFU)/100 mL, interquartile range (IQR: 0-13)] to the drinking cup (median=8 CFU/100 mL; IQR: 0-550; n=81, z=-3.7, p<0.001). About two-thirds (34/52) of drinking vessels were contaminated with E. coli. Although boiling and solar disinfection of water (SODIS) improved the quality of drinking-water (median=0 CFU/100 mL; IQR: 0-0.05), recontamination at the point-of-consumption significantly reduced the quality of water in the cups (median=8, IQR: 0-500; n=45, z=-2.4, p=0.015). Home-based interventions in disinfection of water may not guarantee health benefits without complementary hygiene education due to the risk of posttreatment contamination.
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Technical and social performances of an arsenic-removal technology—the sono arsenic filter—in rural areas of Bangladesh were investigated. Results of arsenic field-test showed that filtered water met the Bangladesh standard (<50 μg/L) after two years of continuous use. A questionnaire was administrated among 198 sono arsenic filter-user and 230 non-user families. Seventy-two percent of filters (n=198) were working at the time of the survey. Another 28% of the filters were abandoned due to breakage. The abandonment percentage (28%) was lower than other mitigation options currently implemented in Bangladesh. Households were reluctant to repair the broken filters on their own. High cost, problems with maintenance of filters, weak sludge-disposal guidance, and slow flow rate were the other demerits of the filter. These results indicate that the implementation approaches of the sono arsenic filter suffered from lack of ownership and long-term sustainability. Continuous use of arsenic-contaminated tubewells by the non-user households demonstrated the lack of alternative water supply in the survey area. Willingness of households to pay (about 30%) and preference of household filter (50%) suggest the need to develop a low-cost household arsenic filter. Development of community-based organization would be also necessary to implement a long-term, sustainable plan for household-based technology.
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O trabalho visa avaliar a efetividade da fluoretação da água de consumo nos sistemas da microrregião de Araçatuba (SP) por meio de 5.157 análises de flúor realizadas no período de 2001 a 2005. Os dados foram analisados com relação ao tipo de manancial e à estrutura dos sistemas, representada pela população dos municípios e tipo de administração. Verificou-se que 51,6 por cento das amostras não atenderam ao padrão de fluoretação e que o maior percentual de atendimento ocorreu nos sistemas operados pela Sabesp (69 por cento), seguidos pelos Grandes (52,1 por cento), estatisticamente semelhantes aos Médios (51,4 por cento), e pelos Pequenos (28 por cento). Sistemas que utilizam água superficial apresentaram desempenho estatisticamente superior ao padrão (60 por cento) em relação aos que utilizam água subterrânea (42,9 por cento). Dentre os últimos, os que exploram o aquífero Guarani foram superiores (52,3 por cento) aos outros (46,6 por cento).
This paper focuses on the drinking-water fluoridation process in Araçatuba region water supply systems by means of 5.157 fluoride concentration data from 2001 to 2005. These data were studied based on the water source, the administration and the structure of the water supply system, according to the population of the county and the type of management. Almost half of samples did not comply the fluoridation standard and the higher compliance was verified in the water supply systems operated by Sabesp (69 percent), followed by the group of Large counties (52 percent), statistically similar to the Medium ones (51.4 percent), and better than the Small ones (28 percent). The systems with surface intakes showed statistically higher performance in the compliance to the standard (60 percent) compared to the ones that use groundwater (42.9 percent). In this last group, those that explore the Guarani aquifer were superior (52.3 percent) than the others (46.6 percent).
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Humans , Drinking Water , Health Education/economics , Vulnerable Populations/education , Water Pollution , MexicoABSTRACT
Objective:To provide the methodology reference for the drinking water quality prediction.Methods:A predictive model of drinking water quality was established by wavelet neural network.The monthly average concentration of potassium permanganate in Chongqing,one drinking water quality parameter,was predicted by the model,and the predictive results were compared with BP neural network.Results:RMSE and MAPE were applied to evaluate the predictive results.The research indicated that the precision of WNN model was superior to that of BP neural network model.Conclusion:The WNN model has better precision for drinking water quality prediction.