scholarly journals Assessment of the Legionnaires’ disease outbreak in Flint, Michigan

2018 ◽  
Vol 115 (8) ◽  
pp. E1730-E1739 ◽  
Author(s):  
Sammy Zahran ◽  
Shawn P. McElmurry ◽  
Paul E. Kilgore ◽  
David Mushinski ◽  
Jack Press ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Census Tract ◽  
Water System ◽  
Disease Outbreak ◽  
Free Chlorine ◽  
Legionnaires Disease ◽  
Genesee County ◽  
Flint River ◽  
Boil Water Advisories

The 2014–2015 Legionnaires’ disease (LD) outbreak in Genesee County, MI, and the outbreak resolution in 2016 coincided with changes in the source of drinking water to Flint’s municipal water system. Following the switch in water supply from Detroit to Flint River water, the odds of a Flint resident presenting with LD increased 6.3-fold (95% CI: 2.5, 14.0). This risk subsided following boil water advisories, likely due to residents avoiding water, and returned to historically normal levels with the switch back in water supply. During the crisis, as the concentration of free chlorine in water delivered to Flint residents decreased, their risk of acquiring LD increased. When the average weekly chlorine level in a census tract was <0.5 mg/L or <0.2 mg/L, the odds of an LD case presenting from a Flint neighborhood increased by a factor of 2.9 (95% CI: 1.4, 6.3) or 3.9 (95% CI: 1.8, 8.7), respectively. During the switch, the risk of a Flint neighborhood having a case of LD increased by 80% per 1 mg/L decrease in free chlorine, as calculated from the extensive variation in chlorine observed. In communities adjacent to Flint, the probability of LD occurring increased with the flow of commuters into Flint. Together, the results support the hypothesis that a system-wide proliferation of legionellae was responsible for the LD outbreak in Genesee County, MI.

scholarly journals Legionnaires' Disease Outbreak at a Resort in Cozumel, Mexico

2016 ◽  
Vol 3 (3) ◽  
Author(s):  
Lee M. Hampton ◽  
Laurel Garrison ◽  
Jessica Kattan ◽  
Ellen Brown ◽  
Natalia A. Kozak-Muiznieks ◽  
...  
Keyword(s):  
United States ◽  
Potable Water ◽  
Water System ◽  
Disease Outbreak ◽  
Community Acquired Pneumonia ◽  
Health Departments ◽  
Medical Providers ◽  
Cozumel Island ◽  
European Working ◽  
Legionnaires Disease

Abstract Background.  A Legionnaires' disease (LD) outbreak at a resort on Cozumel Island in Mexico was investigated by a joint Mexico-United States team in 2010. This is the first reported LD outbreak in Mexico, where LD is not a reportable disease. Methods.  Reports of LD among travelers were solicited from US health departments and the European Working Group for Legionella Infections. Records from the resort and Cozumel Island health facilities were searched for possible LD cases. In April 2010, the resort was searched for possible Legionella exposure sources. The temperature and total chlorine of the water at 38 sites in the resort were measured, and samples from those sites were tested for Legionella. Results.  Nine travelers became ill with laboratory-confirmed LD within 2 weeks of staying at the resort between May 2008 and April 2010. The resort and its potable water system were the only common exposures. No possible LD cases were identified among resort workers. Legionellae were found to have extensively colonized the resort's potable water system. Legionellae matching a case isolate were found in the resort's potable water system. Conclusions.  Medical providers should test for LD when treating community-acquired pneumonia that is severe or affecting patients who traveled in the 2 weeks before the onset of symptoms. When an LD outbreak is detected, the source should be identified and then aggressively remediated. Because LD can occur in tropical and temperate areas, all countries should consider making LD a reportable disease if they have not already done so.

scholarly journals Building a Methodology for Assessing Service Quality under Intermittent Domestic Water Supply

Water ◽  
2018 ◽  
Vol 10 (9) ◽  
pp. 1164 ◽  
Author(s):  
Assia Mokssit ◽  
Bernard de Gouvello ◽  
Aurélie Chazerain ◽  
François Figuères ◽  
Bruno Tassin
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Distribution ◽  
Water System ◽  
Evaluation Framework ◽  
Domestic Water ◽  
Water Service ◽  
Quality Of Water ◽  
History Of

This document proposes a methodology for assessing the quality of water distribution service in the context of intermittent supply, based on a comparison of joint results from literature reviews and feedback from drinking water operators who had managed these networks, with standards for defining the quality of drinking water service. The paper begins by reviewing and proposing an analysis of the definition and characterization of intermittent water supply (IWS), highlighting some important findings. The diversity of approaches used to address the issue and the difficulty of defining a precise and detailed history of water supply in the affected systems broadens the spectrum of intermittency characterization and the problems it raises. The underlined results are then used to structure an evaluation framework for the water service and to develop improvement paths defined in the intermittent networks. The resulting framework highlights the means available to water stakeholders to assess their operational and management performance in achieving the improvement objectives defined by the environmental and socio-economic contexts in which the network operates. Practical examples of intermittent system management are collected from water system operators and presented for illustration purposes (Jeddah, Algiers, Port-au-Prince, Amman, Cartagena, Barranquilla, Mexico, Cancun, Saltillo, Mumbai, Delhi, Coimbatore …).

N-nitrosamine formation by monochloramine, free chlorine, and peracetic acid disinfection with presence of amine precursors in drinking water system

Chemosphere ◽  
2016 ◽  
Vol 153 ◽  
pp. 521-527 ◽  
Author(s):  
Danielle M. West ◽  
Qihua Wu ◽  
Ariel Donovan ◽  
Honglan Shi ◽  
Yinfa Ma ◽  
...  
Keyword(s):  
Drinking Water ◽  
Peracetic Acid ◽  
Water System ◽  
Free Chlorine ◽  
Drinking Water System

scholarly journals Contribution to study of the dependability of a drinking water system

2018 ◽  
Vol 38 (1) ◽  
pp. 11-18
Author(s):  
Djamila Boumelita ◽  
Lahbassi Ouerdachi ◽  
Nasr-Eddine Debbache
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Block Diagram ◽  
Water System ◽  
Spatial Modelling ◽  
Structural Aspect ◽  
Drinking Water System ◽  
Criticality Index ◽  
The City

AbstractIn order to ensure better availability of water resource to different users, we undertook a dependability study of system for drinking water supply. A real case study was done on the water supply network in the city of El Hadjarin Algeria. We started from the site modelling, which provided a calculation of a Hydraulic Criticality Index (HCI) in order to prioritize the importance of pipes in the network. Once the indices were calculated, a modelling procedure of reliability block diagram was applied. The objective was to study and analyse the existing network to measure the water availability problems and try to provide viable solutions. An action on the structural aspect and hardware may be required in order to ensure better availability of water and make the system more reliable. Spatial modelling is also proposed to be able to monitor different parts of the network where problems may occur.

INNOVATIVE WATER SUPPLY METHODS OF SMALL COMMUNITIES

2013 ◽  
Vol 3 (4S) ◽  
pp. 30-32
Author(s):  
Vyachaslav N ZENCOV ◽  
Vladimir D NAZAROV ◽  
Irina V LAPSHAKOVA ◽  
Venera F IMILOVA
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Consumption ◽  
Water System ◽  
Sewage Water ◽  
Biogenic Elements ◽  
Water Drainage ◽  
Small Communities ◽  
Circulating Water ◽  
Circulating Water System

The paper shows the effective way of water supply and water drainage of small communities which consists in the reuse of purified sewage for irrigation purposes. A circulating water system has been developed which has some advantages due to a more simple technological scheme, lower drinking water consumption from the source and the use of biogenic elements of sewage water.

Hospital Characteristics Associated With Colonization of Water Systems byLegionellaand Risk of Nosocomial Legionnaires' Disease: A Cohort Study of 15 Hospitals

1999 ◽  
Vol 20 (12) ◽  
pp. 798-805 ◽  
Author(s):  
Jacob L. Kool ◽  
David Bergmire-Sweat ◽  
Jay C. Butler ◽  
Ellen W. Brown ◽  
Deborah J. Peabody ◽  
...  
Keyword(s):  
Drinking Water ◽  
San Antonio ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Control Measures ◽  
Chlorine Concentration ◽  
Urinary Antigen ◽  
Legionnaires Disease ◽  
Antigen Tests

AbstractObjective:To investigate an increase in reports of legionnaires' disease by multiple hospitals in San Antonio, Texas, and to study risk factors for nosocomial transmission of legionnaires' disease and determinants forLegionellacolonization of hospital hot-water systems.Setting:The 16 largest hospitals in the cities of San Antonio, Temple, and Austin, Texas.Design:Review of laboratory databases to identify patients with legionnaires' disease in the 3 years prior to the investigation and to determine the number of diagnostic tests forLegionellaperformed; measurement of hot-water temperature and chlorine concentration and culture of potable water forLegionella. Exact univariate calculations, Poisson regression, and linear regression were used to determine factors associated with water-system colonization and transmission ofLegionella.Results:Twelve cases of nosocomial legionnaires' disease were identified; eight of these occurred in 1996. The rise in cases occurred shortly after physicians started requestingLegionellaurinary antigen tests. Hospitals that frequently usedLegionellaurinary antigen tests tended to detect more cases of legionnaires' disease.Legionellawas isolated from the water systems of 11 of 12 hospitals in San Antonio; the 12th had just experienced an outbreak of legionnaires' disease and had implemented control measures. Nosocomial legionellosis cases probably occurred in 5 hospitals. The number of nosocomial legionnaires' disease cases in each hospital correlated better with the proportion of water-system sites that tested positive forLegionella (P=.07) than with the concentration ofLegionellabacteria in water samples (P=.23). Hospitals in municipalities where the water treatment plant used monochloramine as a residual disinfectant (n=4) and the hospital that had implemented control measures wereLegionella-free. The hot-water systems of all other hospitals (n=11) were colonized withLegionella. These were all supplied with municipal drinking water that contained free chlorine as a residual disinfectant. In these contaminated hospitals, the proportion of sites testing positive was inversely correlated with free residual chlorine concentration (P=.01). In all hospitals, hot-water temperatures were too low to inhibitLegionellagrowth.Conclusions:The increase in reporting of nosocomial legionnaires' disease was attributable to increased use of urinary antigen tests; prior cases may have gone unrecognized. Risk of legionnaires' disease in hospital patients was better predicted by the proportion of water-system sites testing positive forLegionellathan by the measured concentration ofLegionellabacteria. Use of monochloramine by municipalities for residual drinking water disinfection may help prevent legionnaires' disease.

Outbreak of Legionellosis in a tourist complex in Lanzarote concomitant with a treatment of the water system with megadoses of polyphosphates

1997 ◽  
Vol 35 (11-12) ◽  
pp. 307-309
Author(s):  
S. Crespí ◽  
J. Ferra
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water System ◽  
Drinking Water Supply ◽  
Water Supply Systems ◽  
Chemical Agents ◽  
High Doses ◽  
Supply Systems ◽  
Very High

Polyphosphates are the most universally used chemical agents in anticorrosion treatment of drinking water supply systems, as their addition is generally permitted by law because they lack toxicity at the recommended doses. In this work, we describe an outbreak of Legionellosis in a hotel in Lanzarote in 1993 where the water system had been treated with very high doses of polyphosphates.

Application of stable isotope ratios in drinking water supply system of Ljubljana, Slovenia

2020 ◽  
Author(s):  
Polona Vreča ◽  
Klara Nagode ◽  
Tjaša Kanduč ◽  
Branka Bračič Železnik ◽  
Brigita Jamnik
Keyword(s):  
Drinking Water ◽  
Water Resources ◽  
Stable Isotope ◽  
Water Supply ◽  
Water System ◽  
Water Sources ◽  
Supply System ◽  
Stable Isotope Ratios ◽  
Isotopic Studies ◽  
Drinking Water Supply System

&lt;p&gt;The key to understand the deterioration of the quality of urban water resources is to know the impact of urbanization on the entire waterway, which can change dramatically during the extreme climatic events. Various geochemical parameters, including stable isotope ratios of light elements (H, O, C), represent an important tool to investigate water sources, transport routes, and the mixing of individual components of the water cycle. They are indispensable in urban hydrology, both for characterizing drinking water resources and for evaluating changes within a complex water system.&lt;/p&gt;&lt;p&gt;In Slovenia, the majority of the population is supplied with drinking water from groundwater. In Ljubljana, the capital city of Slovenia, groundwater represents the main drinking water resource. &amp;#160;Therefore, the knowledge and understanding of the groundwater vulnerability is important for the protection and management of water resources. In Ljubljana, the water is supplied through the central water system (WSS), more than 1.000 km long, according to the legislation and the latest standards from five different wellfields (Kle&amp;#269;e, Hrastje, Brest, Jar&amp;#353;ki prod and &amp;#352;entvid). Despite the established water protection areas, the water supply areas are exposed to the pressures of urbanization, industry, transport, agriculture and old environmental burdens, which are often unknown.&lt;/p&gt;&lt;p&gt;In the past, various short-term isotopic studies have been conducted and the Ljubljansko polje and Ljubljansko barje aquifers were characterized. In addition, the sources, paths and interactions of water were determined and the obtained data were used to improve the conceptual model.&lt;/p&gt;&lt;p&gt;However, isotopic studies of water circulation in the drinking water supply system (WSS), which would cover the simultaneous characterization of water sources and changes within the WSS, have not been performed so far. In order to assess the usefulness of isotopes more systematically, we performed the first more detail sampling of water from WSS of Ljubljana in autumn 2018. Sampling was carried out at 103 locations that were selected according to the type of facility in the WSS (i.e. 41 wells, 7 joint exits from water pumping station, 22 water reservoirs, 2 &amp;#160;water treatment locations, 13 fountains, and 19 taps) and according to 9 different WSS areas. Additional samples were collected on River Sava, important infiltration source of groundwater, and at outflow from Ljubljana central wastewater treatment plant. This contribution focuses on presentation of changes of different parameters (i.e. temperature, electrical conductivity, pH, total alkalinity, &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O, &amp;#948;&lt;sup&gt;2&lt;/sup&gt;H and &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C) in WSS of Ljubljana.&lt;/p&gt;

scholarly journals Identifying challenges in drinking water supplies: assessment of boil water advisories in Norway (2008–2019)

2021 ◽  
Author(s):  
Susanne Hyllestad ◽  
Svanhild Schipper Kjørsvik ◽  
Lamprini Veneti ◽  
Ettore Amato
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Distribution System ◽  
Supplementary Information ◽  
Water Supply Systems ◽  
Targeted Interventions ◽  
Public Media ◽  
Boil Water Advisories ◽  
Reporting Rates ◽  
Supply Systems

Abstract The issuing of boil water advisories (BWAs) is a widely used response to microbiological contamination events in drinking water supply systems, and may therefore serve as an indicator for the access to safe drinking water. To supplement data source on the overall status of water supply systems (WSSs) in Norway, we analysed public media reports published in Norway to assess trends, causes, geographical and seasonal distribution of BWAs issued during the period 2008–2019. We identified 1,108 BWA events increasingly reported over the study period but characterised by a decreasing trend in time with respect to duration. The two main frequent causes for BWA were detection of faecal indicator bacteria (42.6%) and risk of contaminants intrusion in the distribution system (21%). We observed higher reporting rates in summer and autumn compared with winter, and higher reporting rates in Northern and Eastern Norwegian regions compared with the Central region. The results of this study could serve as supplementary information to better understand the overall status among WSSs in Norway, particularly in case of recurrent BWA's events, as well as suggest the relevance of BWAs' monitoring in identifying risk factors and planning targeted interventions.

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