The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Thomas Clasen - One of the best experts on this subject based on the ideXlab platform.
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Assessing the association between thermotolerant coliforms in drinking water and Diarrhea: An analysis of individual-level data from multiple studies
Environmental Health Perspectives, 2016Co-Authors: James Hodge, Rachel Peletz, Simon M. Collin, Sophie Boisson, Howard H Chang, Thomas ClasenAbstract:BACKGROUND Fecally-contaminated drinking water is believed to be a major contributor to the global burden of Diarrheal disease and a leading cause of mortality among young children. However, recent systematic reviews and results from blinded studies of water quality interventions have raised questions about the risk associated with fecally-contaminated water, particularly as measured by thermotolerant coliform (TTC) bacteria, a WHO-approved indicator of drinking water quality. OBJECTIVES We investigated the association between TTC in drinking water and Diarrhea using data from seven previous studies. METHODS We obtained individual-level data from available field studies that measured TTC levels in household-drinking water and reported prevalence of Diarrhea among household members during the seven days prior to the visit. RESULTS The combined data set included Diarrhea prevalence on 26,518 individuals and 8,000 water samples from 4,017 households, yielding 45,052 observations. The odds of Diarrhea increased for each log10 increase in TTC/100ml by 18% (95% CI: 11-26%) for children 1000 TTC/100ml, respectively compared to
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field assessment of a novel household based water filtration device a randomised placebo controlled trial in the democratic republic of congo
PLOS ONE, 2010Co-Authors: Sophie Boisson, Mbela Kiyombo, Larry Sthreshley, Saturnin Tumba, Jacques Makambo, Thomas ClasenAbstract:Background: Household water treatment can improve the microbiological quality of drinking water and may prevent Diarrheal diseases. However, current methods of treating water at home have certain shortcomings, and there is evidence of bias in the reported health impact of the intervention in open trial designs. Methods and Findings: We undertook a randomised, double-blinded, placebo-controlled trial among 240 households (1,144 persons) in rural Democratic Republic of Congo to assess the field performance, use and effectiveness of a novel filtration device in preventing Diarrhea. Households were followed up monthly for 12 months. Filters and placebos were monitored for longevity and for microbiological performance by comparing thermotolerant coliform (TTC) levels in influent and effluent water samples. Mean longitudinal prevalence of Diarrhea was estimated among participants of all ages. Compliance was assessed through self-reported use and presence of water in the top vessel of the device at the time of visit. Over the 12-month follow-up period, data were collected for 11,236 person-weeks of observation (81.8% total possible). After adjusting for clustering within the household, the longitudinal prevalence ratio of diarrhoea was 0.85 (95% confidence interval: 0.61–1.20). The filters achieved a 2.98 log reduction in TTC levels while, for reasons that are unclear, the placebos achieved a 1.05 log reduction (p,0.0001). After 8 months, 68% of intervention households met the study’s definition of current users, though most (73% of adults and 95% of children) also reported drinking untreated water the previous day. The filter maintained a constant flow rate over time, though 12.4% of filters were damaged during the course of the study. Conclusions: While the filter was effective in improving water quality, our results provide little evidence that it was protective against Diarrhea. The moderate reduction observed nevertheless supports the need for larger studies that measure impact against a neutral placebo.
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Field assessment of a novel household-based water filtration device: A randomised, placebo-controlled trial in the democratic Republic of Congo
PLoS ONE, 2010Co-Authors: Sophie Boisson, Mbela Kiyombo, Larry Sthreshley, Saturnin Tumba, Jacques Makambo, Thomas ClasenAbstract:Household water treatment can improve the microbiological quality of drinking water and may prevent Diarrheal diseases. However, current methods of treating water at home have certain shortcomings, and there is evidence of bias in the reported health impact of the intervention in open trial designs.We undertook a randomised, double-blinded, placebo-controlled trial among 240 households (1,144 persons) in rural Democratic Republic of Congo to assess the field performance, use and effectiveness of a novel filtration device in preventing Diarrhea. Households were followed up monthly for 12 months. Filters and placebos were monitored for longevity and for microbiological performance by comparing thermotolerant coliform (TTC) levels in influent and effluent water samples. Mean longitudinal prevalence of Diarrhea was estimated among participants of all ages. Compliance was assessed through self-reported use and presence of water in the top vessel of the device at the time of visit. Over the 12-month follow-up period, data were collected for 11,236 person-weeks of observation (81.8{%} total possible). After adjusting for clustering within the household, the longitudinal prevalence ratio of diarrhoea was 0.85 (95{%} confidence interval: 0.61–1.20). The filters achieved a 2.98 log reduction in TTC levels while, for reasons that are unclear, the placebos achieved a 1.05 log reduction (p,0.0001). After 8 months, 68{%} of intervention households met the study’s definition of current users, though most (73{%} of adults and 95{%} of children) also reported drinking untreated water the previous day. The filter maintained a constant flow rate over time, though 12.4{%} of filters were damaged during the course of the study. While the filter was effective in improving water quality, our results provide little evidence that it was protective against Diarrhea. The moderate reduction observed nevertheless supports the need for larger studies that measure impact against a neutral placebo.
Sophie Boisson - One of the best experts on this subject based on the ideXlab platform.
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Assessing the association between thermotolerant coliforms in drinking water and Diarrhea: An analysis of individual-level data from multiple studies
Environmental Health Perspectives, 2016Co-Authors: James Hodge, Rachel Peletz, Simon M. Collin, Sophie Boisson, Howard H Chang, Thomas ClasenAbstract:BACKGROUND Fecally-contaminated drinking water is believed to be a major contributor to the global burden of Diarrheal disease and a leading cause of mortality among young children. However, recent systematic reviews and results from blinded studies of water quality interventions have raised questions about the risk associated with fecally-contaminated water, particularly as measured by thermotolerant coliform (TTC) bacteria, a WHO-approved indicator of drinking water quality. OBJECTIVES We investigated the association between TTC in drinking water and Diarrhea using data from seven previous studies. METHODS We obtained individual-level data from available field studies that measured TTC levels in household-drinking water and reported prevalence of Diarrhea among household members during the seven days prior to the visit. RESULTS The combined data set included Diarrhea prevalence on 26,518 individuals and 8,000 water samples from 4,017 households, yielding 45,052 observations. The odds of Diarrhea increased for each log10 increase in TTC/100ml by 18% (95% CI: 11-26%) for children 1000 TTC/100ml, respectively compared to
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field assessment of a novel household based water filtration device a randomised placebo controlled trial in the democratic republic of congo
PLOS ONE, 2010Co-Authors: Sophie Boisson, Mbela Kiyombo, Larry Sthreshley, Saturnin Tumba, Jacques Makambo, Thomas ClasenAbstract:Background: Household water treatment can improve the microbiological quality of drinking water and may prevent Diarrheal diseases. However, current methods of treating water at home have certain shortcomings, and there is evidence of bias in the reported health impact of the intervention in open trial designs. Methods and Findings: We undertook a randomised, double-blinded, placebo-controlled trial among 240 households (1,144 persons) in rural Democratic Republic of Congo to assess the field performance, use and effectiveness of a novel filtration device in preventing Diarrhea. Households were followed up monthly for 12 months. Filters and placebos were monitored for longevity and for microbiological performance by comparing thermotolerant coliform (TTC) levels in influent and effluent water samples. Mean longitudinal prevalence of Diarrhea was estimated among participants of all ages. Compliance was assessed through self-reported use and presence of water in the top vessel of the device at the time of visit. Over the 12-month follow-up period, data were collected for 11,236 person-weeks of observation (81.8% total possible). After adjusting for clustering within the household, the longitudinal prevalence ratio of diarrhoea was 0.85 (95% confidence interval: 0.61–1.20). The filters achieved a 2.98 log reduction in TTC levels while, for reasons that are unclear, the placebos achieved a 1.05 log reduction (p,0.0001). After 8 months, 68% of intervention households met the study’s definition of current users, though most (73% of adults and 95% of children) also reported drinking untreated water the previous day. The filter maintained a constant flow rate over time, though 12.4% of filters were damaged during the course of the study. Conclusions: While the filter was effective in improving water quality, our results provide little evidence that it was protective against Diarrhea. The moderate reduction observed nevertheless supports the need for larger studies that measure impact against a neutral placebo.
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Field assessment of a novel household-based water filtration device: A randomised, placebo-controlled trial in the democratic Republic of Congo
PLoS ONE, 2010Co-Authors: Sophie Boisson, Mbela Kiyombo, Larry Sthreshley, Saturnin Tumba, Jacques Makambo, Thomas ClasenAbstract:Household water treatment can improve the microbiological quality of drinking water and may prevent Diarrheal diseases. However, current methods of treating water at home have certain shortcomings, and there is evidence of bias in the reported health impact of the intervention in open trial designs.We undertook a randomised, double-blinded, placebo-controlled trial among 240 households (1,144 persons) in rural Democratic Republic of Congo to assess the field performance, use and effectiveness of a novel filtration device in preventing Diarrhea. Households were followed up monthly for 12 months. Filters and placebos were monitored for longevity and for microbiological performance by comparing thermotolerant coliform (TTC) levels in influent and effluent water samples. Mean longitudinal prevalence of Diarrhea was estimated among participants of all ages. Compliance was assessed through self-reported use and presence of water in the top vessel of the device at the time of visit. Over the 12-month follow-up period, data were collected for 11,236 person-weeks of observation (81.8{%} total possible). After adjusting for clustering within the household, the longitudinal prevalence ratio of diarrhoea was 0.85 (95{%} confidence interval: 0.61–1.20). The filters achieved a 2.98 log reduction in TTC levels while, for reasons that are unclear, the placebos achieved a 1.05 log reduction (p,0.0001). After 8 months, 68{%} of intervention households met the study’s definition of current users, though most (73{%} of adults and 95{%} of children) also reported drinking untreated water the previous day. The filter maintained a constant flow rate over time, though 12.4{%} of filters were damaged during the course of the study. While the filter was effective in improving water quality, our results provide little evidence that it was protective against Diarrhea. The moderate reduction observed nevertheless supports the need for larger studies that measure impact against a neutral placebo.
Stephen W. Gundry - One of the best experts on this subject based on the ideXlab platform.
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Short report: Use of ceramic water filtration in the prevention of Diarrheal disease: A randomized controlled trial in rural South Africa and Zimbabwe
American Journal of Tropical Medicine and Hygiene, 2008Co-Authors: Martella Du Preez, James A. Wright, Sibonginkosi Moyo, Natasha Potgieter, Ronan M Conroy, Stephen W. GundryAbstract:To determine the effectiveness of ceramic filters in reducing Diarrhea, we conducted a randomized con-trolled trial in Zimbabwe and South Africa, in which 61 of 115 households received ceramic filters. Incidence of non-bloody and bloody Diarrhea was recorded daily over 6 months using pictorial diaries for children 24–36 months of age. Poisson regression was used to compare incidence rates in intervention and control households. Adjusted for source quality, intervention household drinking water showed reduced Escherichia coli counts (relative risk, 0.67; 95% CI, 0.50–0.89). Zero E. coli were obtained for drinking water in 56.9% of intervention households. The incidence rate ratio for bloody Diarrhea was 0.20 (95% CI, 0.09–0.43; P < 0.001) and for non-bloody Diarrhea was 0.17 (95% CI, 0.08–0.38; P < 0.001), indicating much lower Diarrhea incidence among filter users. The results suggest that ceramic filters are effective in reducing Diarrheal disease incidence. Many people living in developing countries are still reliant on water of poor quality. Figures reported in 2004 by the Joint Monitoring Program showed that, of a population of 734.6 million in sub-Saharan Africa, 56% had no access to a water supply. 1 In South Africa, 34% of households did not have access to a water supply in 2000. 2 For children younger than 5 years of age in South Africa, Diarrhea is the third most important cause of death, after HIV/AIDS and low birth weight, representing 11% of all deaths in that age group.
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Use of ceramic water filtration in the prevention of Diarrheal disease: a randomized controlled trial in rural South Africa and zimbabwe.
The American journal of tropical medicine and hygiene, 2008Co-Authors: Martella Du Preez, James A. Wright, Sibonginkosi Moyo, Natasha Potgieter, Ronan M Conroy, Stephen W. GundryAbstract:To determine the effectiveness of ceramic filters in reducing Diarrhea, we conducted a randomized controlled trial in Zimbabwe and South Africa, in which 61 of 115 households received ceramic filters. Incidence of non-bloody and bloody Diarrhea was recorded daily over 6 months using pictorial diaries for children 24-36 months of age. Poisson regression was used to compare incidence rates in intervention and control households. Adjusted for source quality, intervention household drinking water showed reduced Escherichia coli counts (relative risk, 0.67; 95% CI, 0.50-0.89). Zero E. coli were obtained for drinking water in 56.9% of intervention households. The incidence rate ratio for bloody Diarrhea was 0.20 (95% CI, 0.09-0.43; P < 0.001) and for non-bloody Diarrhea was 0.17 (95% CI, 0.08-0.38; P < 0.001), indicating much lower Diarrhea incidence among filter users. The results suggest that ceramic filters are effective in reducing Diarrheal disease incidence.
John M. Colford - One of the best experts on this subject based on the ideXlab platform.
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Coliform bacteria as indicators of Diarrheal risk in household drinking water: Systematic review and meta-analysis
PLoS ONE, 2014Co-Authors: Joshua S. Gruber, Ayse Ercumen, John M. ColfordAbstract:Abstract Background Current guidelines recommend the use of Escherichia coli (EC) or thermotolerant (“fecal”) coliforms (FC) as indicators of fecal contamination in drinking water. Despite their broad use as measures of water quality, there remains limited evidence for an association between EC or FC and Diarrheal illness: a previous review found no evidence for a link between Diarrhea and these indicators in household drinking water. Objectives We conducted a systematic review and meta-analysis to update the results of the previous review with newly available evidence, to explore differences between EC and FC indicators, and to assess the quality of available evidence. Methods We searched major databases using broad terms for household water quality and Diarrhea. We extracted study characteristics and relative risks (RR) from relevant studies. We pooled RRs using random effects models with inverse variance weighting, and used standard methods to evaluate heterogeneity and publication bias. Results We identified 20 relevant studies; 14 studies provided extractable results for meta-analysis. When combining all studies, we found no association between EC or FC and Diarrhea (RR 1.26 [95% CI: 0.98, 1.63]). When analyzing EC and FC separately, we found evidence for an association between Diarrhea and EC (RR: 1.54 [95% CI: 1.37, 1.74]) but not FC (RR: 1.07 [95% CI: 0.79, 1.45]). Across all studies, we identified several elements of study design and reporting (e.g., timing of outcome and exposure measurement, accounting for correlated outcomes) that could be improved upon in future studies that evaluate the association between drinking water contamination and health. Conclusions Our findings, based on a review of the published literature, suggest that these two coliform groups have different associations with Diarrhea in household drinking water. Our results support the use of EC as a fecal indicator in household drinking water.
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treating water with chlorine at point of use to improve water quality and reduce child Diarrhea in developing countries a systematic review and meta analysis
American Journal of Tropical Medicine and Hygiene, 2007Co-Authors: Benjamin F Arnold, John M. ColfordAbstract:We conducted a systematic review of all studies that measured Diarrheal health impacts in children and the impact on water quality of point-of-use chlorine drinking water treatment. Twenty-one relevant studies were identified from > 856 screened abstracts. Data were extracted and combined using meta-analysis to provide summary estimates of the intervention effect. The intervention reduced the risk of child Diarrhea (pooled relative risk: 0.71, 0.58-0.87) and it reduced the risk of stored water contamination with Escherichia coli (pooled relative risk: 0.20, 0.13-0.30). A major finding from this review is that nearly all trials on this topic have been short (median length was 30 weeks). Although not statistically significant, we observed an attenuation of the intervention's reduction of child Diarrhea in longer trials. Future studies with multi-year follow-up are required to assess the long-term acceptability and sustainability of health impacts shown by the shorter trials identified in this review.
Martella Du Preez - One of the best experts on this subject based on the ideXlab platform.
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Short report: Use of ceramic water filtration in the prevention of Diarrheal disease: A randomized controlled trial in rural South Africa and Zimbabwe
American Journal of Tropical Medicine and Hygiene, 2008Co-Authors: Martella Du Preez, James A. Wright, Sibonginkosi Moyo, Natasha Potgieter, Ronan M Conroy, Stephen W. GundryAbstract:To determine the effectiveness of ceramic filters in reducing Diarrhea, we conducted a randomized con-trolled trial in Zimbabwe and South Africa, in which 61 of 115 households received ceramic filters. Incidence of non-bloody and bloody Diarrhea was recorded daily over 6 months using pictorial diaries for children 24–36 months of age. Poisson regression was used to compare incidence rates in intervention and control households. Adjusted for source quality, intervention household drinking water showed reduced Escherichia coli counts (relative risk, 0.67; 95% CI, 0.50–0.89). Zero E. coli were obtained for drinking water in 56.9% of intervention households. The incidence rate ratio for bloody Diarrhea was 0.20 (95% CI, 0.09–0.43; P < 0.001) and for non-bloody Diarrhea was 0.17 (95% CI, 0.08–0.38; P < 0.001), indicating much lower Diarrhea incidence among filter users. The results suggest that ceramic filters are effective in reducing Diarrheal disease incidence. Many people living in developing countries are still reliant on water of poor quality. Figures reported in 2004 by the Joint Monitoring Program showed that, of a population of 734.6 million in sub-Saharan Africa, 56% had no access to a water supply. 1 In South Africa, 34% of households did not have access to a water supply in 2000. 2 For children younger than 5 years of age in South Africa, Diarrhea is the third most important cause of death, after HIV/AIDS and low birth weight, representing 11% of all deaths in that age group.
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Use of ceramic water filtration in the prevention of Diarrheal disease: a randomized controlled trial in rural South Africa and zimbabwe.
The American journal of tropical medicine and hygiene, 2008Co-Authors: Martella Du Preez, James A. Wright, Sibonginkosi Moyo, Natasha Potgieter, Ronan M Conroy, Stephen W. GundryAbstract:To determine the effectiveness of ceramic filters in reducing Diarrhea, we conducted a randomized controlled trial in Zimbabwe and South Africa, in which 61 of 115 households received ceramic filters. Incidence of non-bloody and bloody Diarrhea was recorded daily over 6 months using pictorial diaries for children 24-36 months of age. Poisson regression was used to compare incidence rates in intervention and control households. Adjusted for source quality, intervention household drinking water showed reduced Escherichia coli counts (relative risk, 0.67; 95% CI, 0.50-0.89). Zero E. coli were obtained for drinking water in 56.9% of intervention households. The incidence rate ratio for bloody Diarrhea was 0.20 (95% CI, 0.09-0.43; P < 0.001) and for non-bloody Diarrhea was 0.17 (95% CI, 0.08-0.38; P < 0.001), indicating much lower Diarrhea incidence among filter users. The results suggest that ceramic filters are effective in reducing Diarrheal disease incidence.
