The Presence of a Specific Genotype of Legionella pneumophila Serogroup 1 in a Hospital and Municipal Water Distribution System over a 12-year Period

2004 ◽  
Vol 36 (6-7) ◽  
pp. 417-423 ◽  
Author(s):  
Johan Darelid ◽  
Sverker Bernander ◽  
Kerstin Jacobson ◽  
Sture Löfgren
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Municipal Water

Determination of cast iron pipe wall decay coefficient for combined chlorine in a municipal water distribution system

2015 ◽  
Vol 42 (4) ◽  
pp. 250-258 ◽  
Author(s):  
Megan J. Liu ◽  
Stephen Craik ◽  
David Z. Zhu
Keyword(s):  
Water Quality ◽  
Cast Iron ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Quality Model ◽  
Quality Model ◽  
Decay Coefficient ◽  
Municipal Water

Predicting disinfectant concentrations in water distribution systems using water quality models requires the input of the wall decay coefficient of the disinfectant. In this study, field water sampling data was integrated with network hydraulic and water quality model simulations of a section of the municipal water distribution system in the City of Edmonton, composed of predominantly cast iron piping, to determine a wall decay coefficient for combined chlorine (chloramine). Unique combined chlorine wall decay coefficients that provided the best fit of model-predicted chlorine concentrations to the field data were determined at two temperatures. Using the determined wall decay coefficients, the water quality model can be used to predict combined chlorine concentrations.

scholarly journals Massive outbreak of viral gastroenteritis associated with consumption of municipal drinking water in a European capital city

2009 ◽  
Vol 137 (12) ◽  
pp. 1713-1720 ◽  
Author(s):  
D. WERBER ◽  
D. LAUŠEVIĆ ◽  
B. MUGOŠA ◽  
Z. VRATNICA ◽  
L. IVANOVIĆ-NIKOLIĆ ◽  
...  
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Control Measures ◽  
Capital City ◽  
Viral Gastroenteritis ◽  
Total Size ◽  
Municipal Water Supply ◽  
Municipal Water ◽  
Large Outbreak

SUMMARYOn 24 August 2008, an outbreak alert regarding cases of acute gastroenteritis in Podgorica triggered investigations to guide control measures. From 23 August to 7 September, 1699 cases were reported in Podgorica (population 136 000) and we estimated the total size of the outbreak to be 10 000–15 000 corresponding to an attack rate of ~10%. We conducted an age- and neighbourhood-matched case-control study, microbiologically analysed faecal and municipal water samples and assessed the water distribution system. All cases (83/83) and 90% (89/90) of controls drank unboiled chlorinated municipal water [matched odds ratio (mOR) 11·2, 95% confidence interval (CI), 1·6–∞]. Consumption of bottled water was inversely associated with illness (mOR 0·3, 95% CI 0·1–0·8). Analyses of faecal samples identified six norovirus genotypes (21/38 samples) and occasionally other viruses. Multiple defects in the water distribution system were noted. These results suggest that the outbreak was caused by faecally contaminated municipal water. It is unusual to have such a large outbreak in a European city especially when the municipal water supply is chlorinated. Therefore, it is important to establish effective multiple-barrier water-treatment systems whenever possible, but even with an established chlorinated supply, sustained vigilance is central to public health.

Treatment of aLegionella pneumophila-Colonized Water Distribution System Using Copper-Silver Ionization and Continuous Chlorination

1999 ◽  
Vol 20 (6) ◽  
pp. 426-428 ◽  
Author(s):  
Amaya Biurrun ◽  
Luis Caballero ◽  
Carmen Pelaz ◽  
Elena León ◽  
Alberto Gago
Keyword(s):  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Cold Water ◽  
Conventional Methods

AbstractThe detection in April 1997 of a case of nosocomial legionellosis in our hospital led to the discovery that both our hot- and cold-water circuits were heavily colonized withLegionella pneumophila. Conventional methods for eradication of the organisms were unsuccessful, so a copper-silver (Cu-Ag) ionization system and a continuous chlorination system were installed. Five months later, the number of colonized sites decreased from an initial 58.3% to 16.7%.

scholarly journals KESEPANCARAN (HOMOLOGI) LEGIONELLA PNEUMOPHILA JARINGAN DISTRIBUSI AIR DAN PNEUMONIA NOSOKOMIAL

2018 ◽  
Vol 16 (1) ◽  
pp. 1
Author(s):  
Noormartany .
Keyword(s):  
New Species ◽  
16S Rrna ◽  
Nosocomial Pneumonia ◽  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Base Sequence ◽  
A New Species

L. pneumophila is one of the nosocomial pneumonia causes that contaminated hospital water distribution system. The aim of this study was to determine the homology between L. pneumophila 16S rRNA base sequence found in the water distribution systemand the sequence derived from the sputum of nosocomial pneumonia patients identified at RSHS Bandung as well as the homology of L. pneumophila 16S rRNA found in the same system network. The study also include the nosocomial pneumonia patients at RSHSBandung with L. pneumophila from GenBank. The research using descriptive bioinformatics BLAST method by comparative analyticapproach, which performed from April 2006 to February 2008. The material consists of 60 biofilm samples from water distributionsystem and pneumonia nosocomial patient’s sputum is positive L.pneumophila from water distribution system in her/his room. Inthe result was found: out of the 60 biofilm samples from the water distribution system, there are seven (7) L. pneumophila positivePCR and culture. During the 12 months of observation, there is only one (1) out of 31 pneumonia nosocomial patients with positively L. pneumophila PCR and culture. The conclusion so far can be mentioned that: The water distribution system in RSHS for patient roomsmay become the source for nosocomial pneumonia transmission of L. pneumophila and also was detected a new species of L. pneumophilathat is genetically different from that has been found in GenBank.

scholarly journals Accumulation and Fate of Microorganisms and Microspheres in Biofilms Formed in a Pilot-Scale Water Distribution System

2005 ◽  
Vol 71 (2) ◽  
pp. 706-712 ◽  
Author(s):  
Jonas Långmark ◽  
Michael V. Storey ◽  
Nicholas J. Ashbolt ◽  
Thor-Axel Stenström
Keyword(s):  
In Situ Hybridization ◽  
Fluorescence In Situ Hybridization ◽  
Residence Time ◽  
Legionella Pneumophila ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Pilot Scale ◽  
Microbial Pathogens

ABSTRACT The accumulation and fate of model microbial “pathogens” within a drinking-water distribution system was investigated in naturally grown biofilms formed in a novel pilot-scale water distribution system provided with chlorinated and UV-treated water. Biofilms were exposed to 1-μm hydrophilic and hydrophobic microspheres, Salmonella bacteriophages 28B, and Legionella pneumophila bacteria, and their fate was monitored over a 38-day period. The accumulation of model pathogens was generally independent of the biofilm cell density and was shown to be dependent on particle surface properties, where hydrophilic spheres accumulated to a larger extent than hydrophobic ones. A higher accumulation of culturable legionellae was measured in the chlorinated system compared to the UV-treated system with increasing residence time. The fate of spheres and fluorescence in situ hybridization-positive legionellae was similar and independent of the primary disinfectant applied and water residence time. The more rapid loss of culturable legionellae compared to the fluorescence in situ hybridization-positive legionellae was attributed to a loss in culturability rather than physical desorption. Loss of bacteriophage 28B plaque-forming ability together with erosion may have affected their fate within biofilms in the pilot-scale distribution system. The current study has demonstrated that desorption was one of the primary mechanisms affecting the loss of microspheres, legionellae, and bacteriophage from biofilms within a pilot-scale distribution system as well as disinfection and biological grazing. In general, two primary disinfection regimens (chlorination and UV treatment) were not shown to have a measurable impact on the accumulation and fate of model microbial pathogens within a water distribution system.

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