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.

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.

scholarly journals Legionella Contamination in Hot Water of Italian Hotels

2005 ◽  
Vol 71 (10) ◽  
pp. 5805-5813 ◽  
Author(s):  
Paola Borella ◽  
Maria Teresa Montagna ◽  
Serena Stampi ◽  
Giovanna Stancanelli ◽  
Vincenzo Romano-Spica ◽  
...  
Keyword(s):  
Risk Factors ◽  
Legionella Pneumophila ◽  
Water Systems ◽  
Hot Water ◽  
Cross Sectional ◽  
Multicenter Survey ◽  
Multivariate Logistic Model ◽  
Legionnaires Disease ◽  
Building Characteristics

ABSTRACT A cross-sectional multicenter survey of Italian hotels was conducted to investigate Legionella spp. contamination of hot water. Chemical parameters (hardness, free chlorine concentration, and trace element concentrations), water systems, and building characteristics were evaluated to study risk factors for colonization. The hot water systems of Italian hotels were strongly colonized by Legionella; 75% of the buildings examined and 60% of the water samples were contaminated, mainly at levels of ≥103 CFU liter−1, and Legionella pneumophila was the most frequently isolated species (87%). L. pneumophila serogroup 1 was isolated from 45.8% of the contaminated sites and from 32.5% of the hotels examined. When a multivariate logistic model was used, only hotel age was associated with contamination, but the risk factors differed depending on the contaminating species and serogroup. Soft water with higher chlorine levels and higher temperatures were associated with L. pneumophila serogroup 1 colonization, whereas the opposite was observed for serogroups 2 to 14. In conclusion, Italian hotels, particularly those located in old buildings, represent a major source of risk for Legionnaires' disease due to the high frequency of Legionella contamination, high germ concentration, and major L. pneumophila serogroup 1 colonization. The possible role of chlorine in favoring the survival of Legionella species is discussed.

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.

scholarly journals Energy Conservation and the Promotion ofLegionella pneumophilaGrowth: The Probable Role of Heat Exchangers in a Nosocomial Outbreak

2016 ◽  
Vol 37 (12) ◽  
pp. 1475-1480 ◽  
Author(s):  
Emilie Bédard ◽  
Simon Lévesque ◽  
Philippe Martin ◽  
Linda Pinsonneault ◽  
Kiran Paranjape ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Water Samples ◽  
Heat Exchangers ◽  
Gel Electrophoresis ◽  
Water System ◽  
Pulsed Field Gel Electrophoresis ◽  
Hot Water ◽  
Nosocomial Outbreak ◽  
Hospital Acquired

OBJECTIVETo determine the source of aLegionella pneumophilaserogroup 5 nosocomial outbreak and the role of the heat exchanger installed on the hot water system within the previous year.SETTINGA 400-bed tertiary care university hospital in Sherbrooke, Canada.METHODSHot water samples were collected and cultured forL. pneumophilafrom 25 taps (baths and sinks) within wing A and 9 taps in wing B. Biofilm (5) and 2 L water samples (3) were collected within the heat exchangers forL. pneumophilaculture and detection of protists. Sequence-based typing was performed on strain DNA extracts and pulsed-field gel electrophoresis patterns were analyzed.RESULTSFollowing 2 cases of hospital-acquired legionellosis, the hot water system investigation revealed a large proportion ofL. pneumophilaserogroup 5 positive taps (22/25 in wing A and 5/9 in wing B). High positivity was also detected in the heat exchanger of wing A in water samples (3/3) and swabs from the heat exchanger (4/5). The outbreak genotyping investigation identified the hot water system as the source of infections. Genotyping results revealed that all isolated environmental strains harbored the same related pulsed-field gel electrophoresis pattern and sequence-based type.CONCLUSIONSTwo cases of hospital-acquired legionellosis occurred in the year following the installation of a heat exchanger to preheat hospital hot water. No cases were reported previously, although the sameL. pneumophilastrain was isolated from the hot water system in 1995. The heat exchanger promotedL. pneumophilagrowth and may have contributed to confirmed clinical cases.Infect. Control Hosp. Epidemiol.2016;1475–1480

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.

Performance of Solar Domestic Hot Water Systems at the National Bureau of Standards—Measurements and Predictions

1983 ◽  
Vol 105 (3) ◽  
pp. 311-321 ◽  
Author(s):  
A. H. Fanney ◽  
S. A. Klein
Keyword(s):  
Heat Exchanger ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Time Interval ◽  
National Bureau ◽  
Domestic Hot Water ◽  
Direct System ◽  
System A ◽  
One Year

The thermal performance of six solar domestic hot water systems and a conventional hot water system have been carefully monitored by the National Bureau of Standards in Gaithersburg, Maryland. The system configurations include an evacuated-tube air system with a crossflow heat exchanger and two storage tanks, a single-tank direct system, a double-tank direct system, a single-tank indirect system with a wrap-around heat exchanger, a double-tank indirect system with a coil-in-tank heat exchanger, and a thermosyphon system. Results are presented for a one-year time interval commencing January 1980. This paper includes a detailed description of the hot-water systems, experimental test results, and comparisons with computer predictions using the f-chart method [1].

scholarly journals Outbreak of Legionnaires' disease at University Hospital, Nottingham. Epidemiology, microbiology and control

1993 ◽  
Vol 110 (1) ◽  
pp. 105-116 ◽  
Author(s):  
A. Colville ◽  
J. Crowley ◽  
D. Dearden ◽  
R. C. B. Slack ◽  
J. V. Lee
Keyword(s):  
Legionella Pneumophila ◽  
Copper Ions ◽  
Virulent Strain ◽  
Water System ◽  
Hot Water ◽  
University Hospital ◽  
Domestic Hot Water ◽  
Large Teaching Hospital ◽  
Legionnaires Disease ◽  
And Control

SUMMARYTwelve patients in a large teaching hospital contracted Legionnaires' disease over a period of 11 months. The source was a domestic hot water system in one of the hospital blocks, which was run at a temperature of 43 °C. Five different subtypes ofLegionella pneumophilaserogroup 1 have been isolated from water in different parts of the hospital, over a period of time. Only one subtype, Benidorm RFLP 14, was implicated in disease. Circumstantial evidence suggested that the outbreak may have been due to recent colonization of the hot water system with a virulent strain ofLegionella pneumophila. The outbreak was controlled by raising the hot water temperature to 60 °C, but careful surveillance uncovered two further cases in the following 30 months. Persistent low numbers ofLegionella pneumophilawere isolated from the domestic hot water of wards where Legionnaires' disease had been contracted, until an electrolytic unit was installed releasing silver and copper ions into this supply.

A simple method for the eradication ofLegionella pneumophilafrom potable water systems

1997 ◽  
Vol 43 (12) ◽  
pp. 1189-1196 ◽  
Author(s):  
Carmen Moreno ◽  
Isabel de Blas ◽  
Francisca Miralles ◽  
David Apraiz ◽  
Vicente Catalan
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cold Water ◽  
Tap Water ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Residual Chlorine ◽  
Water Heater ◽  
Simple Method

In this paper we describe a simple method, noncorrosive to pipes, for the eradication of Legionella pneumophila from potable water systems. This method is based on the systematic purging of the pipe networks with cold water containing 1 – 1.5 mg residual chlorine/L. In the hot water system, a new pipe bypassing the water heater was installed, whereas in the air conditioning system, the circuit is purged with water from the tap water system. The feasibility of this method was studied in two hotels in which the presence of Legionella was detected despite treatment of the water by the hyperchlorination method. The evolution of the presence of Legionella was studied by culture and polymerase chain reaction. Eighty samples from hotel A and sixty-seven samples from hotel B were analyzed during the time that the eradication method was applied. Our results showed that this method permitted the effective elimination of L. pneumophila after 5 months in hotel A and 7 months in hotel B.Key words: Legionella pneumophila, eradication.

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