Safety and Efficacy of Chlorine Dioxide for Legionella Control in a Hospital Water System

2007 ◽  
Vol 28 (8) ◽  
pp. 1009-1012 ◽  
Author(s):  
Zhe Zhang ◽  
Carole McCann ◽  
Janet E. Stout ◽  
Steve Piesczynski ◽  
Robert Hawks ◽  
...  
Keyword(s):  
Chlorine Dioxide ◽  
Environmental Protection Agency ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water System ◽  
Hot Water ◽  
Skilled Nursing ◽  
Legionnaires Disease ◽  
Hospital Acquired

In a 30-month prospective study, we evaluated the efficacy of chlorine dioxide to control Legionella organisms in a water distribution system of a hospital with 364 patient beds and 74 skilled nursing beds. The number of hot water specimens positive for Legionella organisms decreased from 12 (60%) of 20 to 2 (10%) of 20. An extended time (18 months) was needed to achieve a significant reduction in the rate of Legionella positivity among hot water specimens. At the time of writing, no cases of hospital-acquired Legionnaires disease have been detected at the hospital since the chlorine dioxide system was installed in January 2003. Use of chlorine dioxide was safe, based on Environmental Protection Agency limits regarding maximum concentrations of chlorine dioxide and chlorite.

Biofilm formation in a hot water system

2002 ◽  
Vol 46 (9) ◽  
pp. 95-101 ◽  
Author(s):  
L.K. Bagh ◽  
H.-J. Albrechtsen ◽  
E. Arvin ◽  
K. Ovesen
Keyword(s):  
Distribution System ◽  
Biofilm Formation ◽  
Water Distribution ◽  
Water Distribution System ◽  
Formation Rate ◽  
Water System ◽  
Hot Water ◽  
Water Tank ◽  
Number Of Bacteria

The biofilm formation rate was measured in situ in a hot water system in an apartment building by specially designed sampling equipment, and the net growth of the suspended bacteria was measured by incubation of water samples with the indigeneous bacteria. The biofilm formation rate reached a higher level in the hot water distribution system (2.1 d−1 to 2.3 d−1) than in the hot water tank (1.4 d−1 to 2.2 d−1) indicating an important area for surface associated growth. The net growth rate of the suspended bacteria measured in hot water from the top, middle and bottom of the hot water tank, in the sludge, or in the water from the distribution system was negligible. This indicated that bacterial growth took place on the inner surfaces in the hot water system and biofilm formation and detachment of bacteria could account for most of the suspended bacteria actually measured in hot water. Therefore, attempts to reduce the number of bacteria in a hot water system have to include the distribution system as well as the hot water tank.

Isolation of Legionella pneumophila from the Cold Water of Hospital Ice Machines: Implications for Origin and Transmission of the Organism

1985 ◽  
Vol 6 (4) ◽  
pp. 141-146 ◽  
Author(s):  
Janet E. Stout ◽  
Victor L. Yu ◽  
Paul Muraca
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Cold Water ◽  
Water System ◽  
Primary Source ◽  
Hot Water ◽  
Hospital Environment ◽  
Water Storage Tank

AbstractAlthough the mode of transmission of L. pneumophila is as yet unclear, the hot water distribution system has been shown to be the reservoir for Legionella within the hospital environment. In this report we identify a previously unrecognized reservoir for L. pneumophila within the hospital environment, ie, the cold water dispensers of hospital ice machines. The cold water dispensers of 14 ice machines were cultured monthly over a 1-year period. Positive cultures were obtained from 8 of 14 dispensers, yielding from 1 to 300 CFU/plate. We were able to link the positivity of these cold water sites to the incoming cold water supply by recovering L. pneumophila from the cold water storage tank, which is directly supplied by the incoming municipal water line. This was accomplished by a novel enrichment experiment designed to duplicate the conditions (temperature, sediment, stagnation, and continuous seeding) of the hot water system. Our data indicate that significant contamination of cold water outlets with L. pneumophila can occur. Although no epidemiologic link to disease was made, the fact that the primary source of a patient's drinking water is from the ice machines warrants further investigation of these water sources as possible reservoirs.

Cytopathogenicity and molecular subtyping ofLegionella pneumophilaenvironmental isolates from 17 hospitals

2008 ◽  
Vol 137 (2) ◽  
pp. 188-193 ◽  
Author(s):  
M. GARCIA-NUÑEZ ◽  
M. L. PEDRO-BOTET ◽  
S. RAGULL ◽  
N. SOPENA ◽  
J. MORERA ◽  
...  
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Cytopathic Effect ◽  
Water Distribution System ◽  
Water Reservoir ◽  
Pfge Pattern ◽  
Contaminated Water ◽  
Legionnaires Disease ◽  
Hospital Acquired

SUMMARYThe cytopathogenicity of 22Legionella pneumophilaisolates from 17 hospitals was determined by assessing the dose of bacteria necessary to produce 50% cytopathic effect (CPED50) in U937 human-derived macrophages. All isolates were able to infect and grow in macrophage-like cells (range log10CPED50: 2·67–6·73 c.f.u./ml). Five groups were established and related to the serogroup, the number of PFGE patterns coexisting in the same hospital water distribution system, and the possible reporting of hospital-acquired Legionnaires' disease cases.L. pneumophilaserogroup 1 isolates had the highest cytopathogenicity (P=0·003). Moreover, a trend to more cytopathogenic groups (groups 1–3) in hospitals with more than one PFGE pattern ofL. pneumophilain the water distribution system (60%vs. 17%) and in hospitals reporting cases of hospital-acquired Legionnaires' disease (36·3%vs. 16·6%) was observed. We conclude that the cytopathogenicty of environmentalL. pneumophilashould be taken into account in evaluating the risk of a contaminated water reservoir in a hospital and hospital acquisition of Legionnaires' disease.

scholarly journals Outbreak of Legionnaires' disease in a nursing home, Slovenia, August 2010: preliminary report

2010 ◽  
Vol 15 (39) ◽  
Author(s):  
A Trop Skaza ◽  
L Beskovnik ◽  
A Storman ◽  
S Ursic ◽  
B Groboljsek ◽  
...  
Keyword(s):  
Nursing Home ◽  
Distribution System ◽  
Preliminary Report ◽  
Water Distribution ◽  
Water Distribution System ◽  
Source Of Infection ◽  
Dead End ◽  
Probable Source ◽  
Legionnaires Disease

We report an outbreak of Legionnaires' disease in a nursing home in Slovenia in August 2010 affecting 15 of 234 residents. To date, Legionnaires' disease has been confirmed in four patients. Further serum analyses and genotyping of isolates are ongoing. The building's water distribution system with dead end sections has been identified as the probable source of infection.

scholarly journals Hot Water Distribution System Program Documentation and Comparison to Experimental Data

2007 ◽  
Author(s):  
Evelyn Baskin ◽  
William G Craddick ◽  
Roberto Lenarduzzi ◽  
Robert L Wendt ◽  
Professor Keith A. Woodbury
Keyword(s):  
Experimental Data ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Hot Water ◽  
System Program

scholarly journals THE ANALYSIS OF WATER SPEED INFLUENCE IN HOT-WATER DISTRIBUTION SYSTEM ON THE AMOUNT OF HEAT LOSS

2021 ◽  
Vol 2021 (1) ◽  
pp. 23-28
Author(s):  
Peter Kapalo ◽  
◽  
Khrystyna Kozak ◽  
Khrystyna Myroniuk ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Ventilation System ◽  
Hot Water ◽  
Graphical Form ◽  
Hot Water Supply System

One of the main tasks around the world is to reduce energy consumption with constant consumer comfort. The hot water supply system uses a significant part of thermal energy and requires no less attention than the heating or ventilation system. The amount of heat loss from hot water distribution systems is of great importance for the energy consumption of buildings. In winter, part of this heat is used for space heating, in summer they are unused and is considered as lost heat. For this reason, this paper considers the influence of water velocity in the pipe, pipe size, and water temperature on the total heat losses in the insulated hot-water distribution system. The data are presented in tabular and graphical form. A graph of the dependence of the amount of heat loss on the temperature and velocity of hot water is obtained.

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