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.

Nosocomial Outbreak of Legionnaires' Disease: Molecular Epidemiology and Disease Control Measures

1987 ◽  
Vol 8 (2) ◽  
pp. 53-58 ◽  
Author(s):  
Jeffrey M. Johnston ◽  
Robert H. Latham ◽  
Frederick A. Meier ◽  
Jon A. Green ◽  
Rebecca Boshard ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cooling Tower ◽  
Water System ◽  
Hot Water ◽  
Control Measures ◽  
Laboratory Techniques ◽  
Legionnaires Disease ◽  
Water Holding ◽  
Methods Of Control

AbstractMolecular laboratory techniques were used to study the epidemiology of an outbreak of nosocomial Legionnaires' disease. All patient isolates were Legionella pneumophila serogroup 1 and showed identical plasmid profiles and reactions with serogroup-specific monoclonal antibodies. L pneumophila was also cultured from four of five cooling tower water samples; however, the isolate from only one tower was serogroup 1 of the same sub-type as patient isolates. Since the cases were temporally clustered and epidemiologically associated with exposure to cooling tower aerosols, the single cooling tower implicated by molecular analysis was the most likely source of the outbreak. Chlorination of cooling tower ponds has eradicated the epidemic strain. Since potable water also harbored the infecting organism and was the probable source for cooling tower contamination, decontamination of the hospital water system was also undertaken. Superchlorination of hot water holding tanks to 17 ppm on a weekly basis has effectively eradicated L pneumophila from the potable water system and appears to be a reasonable, simple, and relatively inexpensive alternative to previously described methods of control.

Sporadic Legionnaires' disease: the role of domestic electric hot-water tanks

2011 ◽  
Vol 140 (1) ◽  
pp. 172-181 ◽  
Author(s):  
S. F. DUFRESNE ◽  
M. C. LOCAS ◽  
A. DUCHESNE ◽  
C. RESTIERI ◽  
J. ISMAÏL ◽  
...  
Keyword(s):  
Potable Water ◽  
Water System ◽  
Water Systems ◽  
Pulsed Field Gel Electrophoresis ◽  
Hot Water ◽  
Clinical Isolates ◽  
Domestic Hot Water ◽  
Legionnaires Disease ◽  
Water Tanks

SUMMARYSporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated withLegionellaspp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the sameLegionellaisolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study.Legionellawas recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.

scholarly journals An approach for developing a national estimate of waterborne disease due to drinking water and a national estimate model application

2006 ◽  
Vol 4 (S2) ◽  
pp. 201-240 ◽  
Author(s):  
Michael Messner ◽  
Susan Shaw ◽  
Stig Regli ◽  
Ken Rotert ◽  
Valerie Blank ◽  
...  
Keyword(s):  
Drinking Water ◽  
Environmental Protection Agency ◽  
Water System ◽  
Credible Interval ◽  
The United States ◽  
Water Systems ◽  
Epidemiologic Studies ◽  
Incidence Rates ◽  
Waterborne Disease ◽  
Public Water Systems

In this paper, the US Environmental Protection Agency (EPA) presents an approach and a national estimate of drinking water related endemic acute gastrointestinal illness (AGI) that uses information from epidemiologic studies. There have been a limited number of epidemiologic studies that have measured waterborne disease occurrence in the United States. For this analysis, we assume that certain unknown incidence of AGI in each public drinking water system is due to drinking water and that a statistical distribution of the different incidence rates for the population served by each system can be estimated to inform a mean national estimate of AGI illness due to drinking water. Data from public water systems suggest that the incidence rate of AGI due to drinking water may vary by several orders of magnitude. In addition, data from epidemiologic studies show AGI incidence due to drinking water ranging from essentially none (or less than the study detection level) to a rate of 0.26 cases per person-year. Considering these two perspectives collectively, and associated uncertainties, EPA has developed an analytical approach and model for generating a national estimate of annual AGI illness due to drinking water. EPA developed a national estimate of waterborne disease to address, in part, the 1996 Safe Drinking Water Act Amendments. The national estimate uses best available science, but also recognizes gaps in the data to support some of the model assumptions and uncertainties in the estimate. Based on the model presented, EPA estimates a mean incidence of AGI attributable to drinking water of 0.06 cases per year (with a 95% credible interval of 0.02–0.12). The mean estimate represents approximately 8.5% of cases of AGI illness due to all causes among the population served by community water systems. The estimated incidence translates to 16.4 million cases/year among the same population. The estimate illustrates the potential usefulness and challenges of the approach, and provides a focus for discussions of data needs and future study designs. Areas of major uncertainty that currently limit the usefulness of the approach are discussed in the context of the estimate analysis.

Computational framework for evaluating risk trade-offs in costs associated with Legionnaires’ Disease risk, energy, and scalding risk for hospital hot water systems

2021 ◽  
Author(s):  
Ashley Heida ◽  
Alexis Mraz ◽  
Mark Hamilton ◽  
Mark Weir ◽  
Kerry A Hamilton
Keyword(s):  
Legionella Pneumophila ◽  
Disease Risk ◽  
Disease Outbreaks ◽  
Febrile Illness ◽  
Water Systems ◽  
Hot Water ◽  
Computational Framework ◽  
Trade Offs ◽  
Pontiac Fever ◽  
Legionnaires Disease

Legionella pneumophila are bacteria that when inhaled cause Legionnaires’ Disease (LD) and febrile illness Pontiac Fever. As of 2014, LD is the most frequent cause of waterborne disease outbreaks due...

scholarly journals Evaluating the use and intent of drinking water advisories in Atlantic Canada

Water Policy ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 908-924
Author(s):  
Kaycie Lane ◽  
Graham Gagnon
Keyword(s):  
Risk Management ◽  
Drinking Water ◽  
Water System ◽  
Water Systems ◽  
Alternative Methods ◽  
Atlantic Canada ◽  
Water Safety ◽  
Proactive Management ◽  
Management Measures ◽  
Over Time

Abstract Drinking water advisories (DWAs) are used as a tool for identifying water safety concerns in many jurisdictions. Evidence from previous research demonstrates a lack of improvement in water system operations over time, with an increase in the total number of DWAs in place. DWAs are predominantly issued due to operational concerns within a water system, implying a lack of proactive management measures for preventable issues. Therefore, DWAs represent a chronic issue for many water systems, particularly those lacking resources to implement operational improvements. This study explores DWA characteristics in Atlantic Canada, including frequency and duration, focusing on municipal and private water systems. Seasonality was identified as a trend in DWA issuance in Nova Scotia, and reasons for DWA issuance are largely unchanged over time. Neither of these identified concerns has led to a change in DWA reporting or issuance procedures. Additionally, this study identifies a lack of a common reporting format, leading to the proposal of a template of minimum characteristics for future DWA reporting. Overall, this study highlights deficiencies in the DWA issuance process as a water safety measure and suggests alternative methods for risk management in water systems to alleviate the persistence and prevalence of DWAs in Canada.

scholarly journals Evaluation of Legionella spp. Colonization in Residential Buildings Having Solar Thermal System for Hot Water Production

2020 ◽  
Vol 17 (19) ◽  
pp. 7050
Author(s):  
Michele Totaro ◽  
Anna Laura Costa ◽  
Lorenzo Frendo ◽  
Sara Profeti ◽  
Beatrice Casini ◽  
...  
Keyword(s):  
Cold Water ◽  
Disease Risk ◽  
Residential Buildings ◽  
Water Systems ◽  
Hot Water ◽  
Solar Thermal ◽  
Water Production ◽  
Systems Maintenance ◽  
Legionnaires Disease ◽  
Cold Water Temperature

Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires’ disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires’ disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.

Effect of heat flushing on the concentrations of Legionella pneumophila and other heterotrophic microbes in hot water systems of apartment buildings

1996 ◽  
Vol 42 (8) ◽  
pp. 811-818 ◽  
Author(s):  
Outi M. Zacheus ◽  
Pertti J. Martikainen
Keyword(s):  
Water Temperature ◽  
Legionella Pneumophila ◽  
Heterotrophic Bacteria ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Circulating Water ◽  
Heterotrophic Microbes ◽  
Before And After ◽  
Circulating Water System

The decontamination of Legionella pneumophila and other heterotrophic microbes by heat flushing in four legionellae-positive hot water systems was studied. Before the decontamination procedure, the concentration of legionellae varied from 3.0 × 10−3 to 3.5 × 10−5 cfu/L and the hot water temperature from 43.6 to 51.5 °C. During the contamination the temperature was raised to 60–70 °C. All taps and showers were cleaned from sediments and flushed with hot water twice a day for several minutes. The decontamination lasted for 2–4 weeks. In a few weeks the heat-flushing method reduced the concentration of legionellae below the detection limit (50 cfu/L) in the hot circulating water system just before and after the heat exchanger. The high hot water temperature also decreased the viable counts of heterotrophic bacteria, fungi, and total microbial cells determined by the epifluorescent microscopy. However, the eradication of legionellae failed in a water system where the water temperature remained below 60 °C in some parts of the system. After the decontamination, the temperature of hot water was lowered to 55 °C. Thereafter, all the studied hot water systems were recolonized by legionellae within a few months, showing that the decontamination by heat flushing was temporary. Also, the contamination of other bacteria increased in a few months to the level before decontamination.Key words: legionellae, hot water system, decontamination, water temperature, heterotrophic bacteria.

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.

Comparison between Energy Performance of Building and Investments to the Renewable Energy Sources

2014 ◽  
Vol 1020 ◽  
pp. 518-523
Author(s):  
Martin Kovac ◽  
Katarina Knizova
Keyword(s):  
Renewable Energy Sources ◽  
Water System ◽  
Energy Performance ◽  
Water Systems ◽  
Hot Water ◽  
Operating Costs ◽  
Energy Sources ◽  
Domestic Hot Water ◽  
Know How ◽  
The Subject

The subject of the paper is to calculate the energy performance of building in proposed variants. The differences in the variants are in the using of conventional and renewable sources for heating and domestic hot water system. Target of the second part of paper is to know, how much money we need to invest into the proposed variants for heating and domestic hot water systems and how much money will by the user paying for operating costs. The conclusion of the paper describes the payback periods of proposed variants.

scholarly journals Introduction of Monochloramine into a Municipal Water System: Impact on Colonization of Buildings by Legionella spp

2006 ◽  
Vol 72 (1) ◽  
pp. 378-383 ◽  
Author(s):  
Matthew R. Moore ◽  
Marsha Pryor ◽  
Barry Fields ◽  
Claressa Lucas ◽  
Maureen Phelan ◽  
...  
Keyword(s):  
Potable Water ◽  
Sampling Site ◽  
Water System ◽  
Water Source ◽  
Water Systems ◽  
Hot Water ◽  
County Government ◽  
Single Family ◽  
Pinellas County ◽  
Municipal Water

ABSTRACT Legionnaires' disease (LD) outbreaks are often traced to colonized potable water systems. We collected water samples from potable water systems of 96 buildings in Pinellas County, Florida, between January and April 2002, during a time when chlorine was the primary residual disinfectant, and from the same buildings between June and September 2002, immediately after monochloramine was introduced into the municipal water system. Samples were cultured for legionellae and amoebae using standard methods. We determined predictors of Legionella colonization of individual buildings and of individual sampling sites. During the chlorine phase, 19 (19.8%) buildings were colonized with legionellae in at least one sampling site. During the monochloramine phase, six (6.2%) buildings were colonized. In the chlorine phase, predictors of Legionella colonization included water source (source B compared to all others, adjusted odds ratio [aOR], 6.7; 95% confidence interval [CI], 2.0 to 23) and the presence of a system with continuously circulating hot water (aOR, 9.8; 95% CI, 1.9 to 51). In the monochloramine phase, there were no predictors of individual building colonization, although we observed a trend toward greater effectiveness of monochloramine in hotels and single-family homes than in county government buildings. The presence of amoebae predicted Legionella colonization at individual sampling sites in both phases (OR ranged from 15 to 46, depending on the phase and sampling site). The routine introduction of monochloramine into a municipal drinking water system appears to have reduced colonization by Legionella spp. in buildings served by the system. Monochloramine may hold promise as community-wide intervention for the prevention of LD.

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