Long-Term Effects of Hospital Water Network Disinfection onLegionellaand Other Waterborne Bacteria in an Italian University Hospital

2014 ◽  
Vol 35 (3) ◽  
pp. 293-299 ◽  
Author(s):  
Beatrice Casini ◽  
Andrea Buzzigoli ◽  
Maria Luisa Cristina ◽  
Anna Maria Spagnolo ◽  
Pietro Del Giudice ◽  
...  

Objective and Design.Legionellacontrol still remains a critical issue in healthcare settings where the preferred approach to health risk assessment and management is to develop a water safety plan. We report the experience of a university hospital, where a water safety plan has been applied since 2002, and the results obtained with the application of different methods for disinfecting hot water distribution systems in order to provide guidance for the management of water risk.Interventions.The disinfection procedures included continuous chlorination with chlorine dioxide (0.4–0.6 mg/L in recirculation loops) reinforced by endpoint filtration in critical areas and a water treatment based on monochloramine (2-3 mg/L). Real-time polymerase chain reaction and a new immunoseparation and adenosine triphosphate bioluminescence analysis were applied in environmental monitoring.Results.After 9 years, the integrated disinfection-filtration strategy significantly reduced positive sites by 55% and the mean count by 78% (P< .05); however, the high costs and the occurrence of a chlorine-tolerant clone belonging toLegionella pneumophilaST269 prompted us to test a new disinfectant. The shift to monochloramine allowed us to eliminate planktonicLegionellaand did not require additional endpoint filtration; however, nontuberculous mycobacteria were isolated more frequently as long as the monochloramine concentration was 2 mg/L; their cultivability was never regained by increasing the concentration up to 3 mg/L.Conclusions.Any disinfection method needs to be adjusted/fine-tuned in individual hospitals in order to maintain satisfactory results over time, and only a locally adapted evidence-based approach allows assessment of the efficacy and disadvantages of the control measures.

Author(s):  
Maria Coniglio ◽  
Margherita Ferrante ◽  
Mohamed Yassin

The purpose of this study is to report the experience of the implementation and application of a 3-year Water Safety Plan (WSP) together with the secondary disinfection of water by monochloramine to control and prevent healthcare-associated legionellosis in an Italian hospital strongly colonized by Legionella. Risk assessment was carried out by the WSP team. The main critical control points focused on in developing the WSP for the control of Legionella was the water distribution system. A sampling plan for the detection of Legionella was implemented. A widespread contamination of the hot water distribution system by L. pneumophila sg5 was found. Results after 3 years of the continuous disinfection of hot water with monochloramine indicate the eradication of Legionella. The implementation and application of a WSP in a hospital, together with the disinfection of the water distribution system with monochloramine, can be effective in controlling the growth of Legionella and in preventing nosocomial legionellosis.


2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
G Noberasco ◽  
A Battaglini ◽  
F Grammatico ◽  
M Zacconi ◽  
A Battistini ◽  
...  

Abstract Background Legionella contamination of hospital water distribution system still remains a critical issue in healthcare settings, despite the disputed relationship between environmental legionella and hospital-acquired legionellosis. We report the experience of our 1200-beds hospital, where a new water safety plan (WSP) has been applied since 2017, and the results obtained with the application of different methods to control Legionella water contamination, especially in critical areas. Methods Policlinico San Martino is the referral tertiary acute-care university hospital in Liguria region, North-West Italy. It’s made of 21 buildings of different dimensions, 7 of which host high risk patients, according to Italian Guidelines for legionellosis prevention and control. A sampling plan for Legionella detection was implemented in 2017, focusing on the water network critical points. Different secondary disinfection procedures were used, including systemic (chlorine dioxide, monochloramine), focal (point-of-use filtration) and short-term methods (hyperchlorination), the last in case of contamination higher than 10^4 CFU/l. Results Respectively, during 2017 and 2018 a total of 201 and 119 hot water samples were collected, distributed among the 7 critical buildings of the hospital. Negative samples raised from 69.7% to 74.8%, while positive samples &gt;10^3 CFU/l (recommended cut-off for acute disinfection according to Italian guidelines) lowered from 21.9% to 9.2% of total samples. Out of 55 positive samples, Legionella sg 3 accounted for 98.2% of the total. Conclusions The new WSP determined a significant reduction of Legionella contamination of water distribution networks in our hospital critical buildings. The continuous surveillance of critical water system points provided evidence to elaborate an effective protocol for routine and extraordinary disinfection interventions, as result of a close collaboration between hospital hygiene unit and engineering and technical services. Key messages The implementation of an effective water safety plan and different disinfection procedures in hospital critical areas allow us to reduce and control the risk of hospital-acquired Legionella infection. Continuous surveillance cultures of drinking water to detect Legionella are necessary to adapt disinfection methods to local results.


2021 ◽  
Vol 11 (3) ◽  
pp. 247-253
Author(s):  
Annunziata D’Orazio ◽  
Leo Poggi

The paper illustrates the design and drafting of the Water Safety Plan (WSP) of a health facility, particularly with regard to water intended for human consumption. The components already present in the water and sanitary system as well as the control measures already provided, are described and critically discussed. Following the hazards identification and risk assessment related to the plant, some corrective measures and actions that have been proposed and implemented, are discussed.


Author(s):  
Francesca Serio ◽  
Lucia Martella ◽  
Giovanni Imbriani ◽  
Adele Idolo ◽  
Francesco Bagordo ◽  
...  

Background: The quality of water for human consumption is an objective of fundamental importance for the defense of public health. Since the management of networks involves many problems of control and efficiency of distribution, the Water Safety Plan (WSP) was introduced to address these growing problems. Methods: WSP was applied to three companies in which the water resource assumes central importance: five water kiosks, a third-range vegetable processing company, and a residence and care institution. In drafting the plan, the terms and procedures designed and tested for the management of urban distribution systems were applied to safeguard the resource over time. Results: The case studies demonstrated the reliability of the application of the model even to small drinking-water systems, even though it involved a greater effort in analyzing the incoming water, the local intended use, and the possibilities for managing the containment of the dangers to which it is exposed. This approach demonstrates concrete effectiveness in identifying and mitigating the dangers of altering the quality of water. Conclusions: Thanks to the WSP applied to small drinking-water systems, we can move from management that is focused mainly on verifying the conformity of the finished product to the creation of a global risk assessment and management system that covers the entire water supply chain.


1987 ◽  
Vol 8 (9) ◽  
pp. 357-363 ◽  
Author(s):  
Richard M. Vickers ◽  
Victor L. Yu ◽  
S. Sue Hanna ◽  
Paul Muraca ◽  
Warren Diven ◽  
...  

AbstractWe conducted a prospective environmental study for Legionella pneumophila in 15 hospitals in Pennsylvania. Hot water tanks, cold water sites, faucets, and show-erheads were surveyed four times over a one-year period. Sixty percent (9/15) of hospitals surveyed were contaminated with L pneumophila. Although contamination could not be linked to a specific municipal water supplier, most of the contaminated supplies came from rivers. Parameters found to be significantly associated with contamination included elevated hot water temperature, vertical configuration of the hot water tank, older tanks, and elevated calcium and magnesium concentrations of the water (P < 0.05). This study suggests that L pneumophila contamination could be predicted based on design of the distribution system, as well as physicochemical characteristics of the water.


Author(s):  
Luna Girolamini ◽  
Silvano Salaris ◽  
Jessica Lizzadro ◽  
Marta Mazzotta ◽  
Maria Rosaria Pascale ◽  
...  

In this study, we aimed to associate the molecular typing of Legionella isolates with a culture technique during routine Legionella hospital environmental surveillance in hot water distribution systems (HWDSs) to develop a risk map able to be used to prevent nosocomial infections and formulate appropriate preventive measures. Hot water samples were cultured according to ISO 11731:2017. The isolates were serotyped using an agglutination test and genotyped by sequence-based typing (SBT) for Legionella pneumophila or macrophage infectivity potentiator (mip) gene sequencing for non-pneumophila Legionella species. The isolates’ relationship was phylogenetically analyzed. The Legionella distribution and level of contamination were studied in relation to temperature and disinfectant residues. The culture technique detected 62.21% of Legionella positive samples, characterized by L. pneumophila serogroup 1, Legionella non-pneumophila, or both simultaneously. The SBT assigned two sequence types (STs): ST1, the most prevalent in Italy, and ST104, which had never been isolated before. The mip gene sequencing detected L. anisa and L. rubrilucens. The phylogenetic analysis showed distinct clusters for each species. The distribution of Legionella isolates showed significant differences between buildings, with a negative correlation between the measured level of contamination, disinfectant, and temperature. The Legionella molecular approach introduced in HWDSs environmental surveillance permits (i) a risk map to be outlined that can help formulate appropriate disinfection strategies and (ii) rapid epidemiological investigations to quickly identify the source of Legionella infections.


2012 ◽  
Vol 12 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Ernest Mayr ◽  
Aditya Lukas ◽  
Wolfgang Aichlseder ◽  
Reinhard Perfler

The Water Safety Plan (WSP) is considered the preferred approach to ensure drinking water safety by the World Health Organization (WHO). This approach ideally requires extensive scientific and technical input from a multidisciplinary team of experts. However, in small- and medium-sized municipalities in Austria, financial and personnel resources are usually of very limited availability. Therefore, a spreadsheet based WSP tool was designed to facilitate the implementation of the WSP approach at these small supply units. The WSP tool comprises the relevant national Austrian guidelines, which include the key components of the WSP by the WHO. The tool provides an overview of the required steps, explains how to carry out each step and guides the user through the three key components: system and hazards assessment, control measures and operational monitoring, and management. The practical application of the WSP tool was tested at 12 water utilities over a period of three months. After this period, the tool was improved based on collected feedback from the water utilities.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2304
Author(s):  
Giovanna Deiana ◽  
Antonella Arghittu ◽  
Marco Dettori ◽  
Maria Dolores Masia ◽  
Maria Grazia Deriu ◽  
...  

The occurrence of Legionella spp. in the water distribution systems of large hospitals and other healthcare facilities is considered particularly dangerous, due to the critical nature of the hospitalized patients. The aim of this study is to present a pluri-annual environmental surveillance in a large university hospital assessing the prevalence of Legionella spp. and underlining its variability over the years. The samples of water were collected in accordance with the Italian National Guidelines and the sampling sites considered in this study were selected favoring wards with very high-risk patients and with patients at increased risk. The laboratory analyzed a total of 305 water samples deriving from 24 different sampling points. Legionella spp. were detected in 39.4% of samples, the majority of which were contaminated by Legionella pneumophila serogroups 2–14 (68.7%). Statistically significant differences were found among different seasons with a linear trend in positive proportion from summer to spring. Several experimental interventions to prevent and reduce Legionella colonization were attempted, but there is no a definitive method for the complete eradication of this microorganism. The permanent monitoring of hospital water distribution systems is fundamental to preventing the potential risk of nosocomial Legionellosis and to implementing procedures to minimize the risk of Legionella spp. colonization.


2015 ◽  
Vol 71 ◽  
pp. 244-256 ◽  
Author(s):  
Emilie Bédard ◽  
Stéphanie Fey ◽  
Dominique Charron ◽  
Cindy Lalancette ◽  
Philippe Cantin ◽  
...  

2018 ◽  
Vol 2018 ◽  
pp. 1-5 ◽  
Author(s):  
Maria A. Kyritsi ◽  
Varvara A. Mouchtouri ◽  
Anna Katsiafliaka ◽  
Foteini Kolokythopoulou ◽  
Elias Plakokefalos ◽  
...  

Healthcare-associated Legionnaires’ disease often leads to fatal respiratory tract infection among hospitalized patients. In this report, three cases of Legionnaires’ disease among patients in two different hospitals (Hospital A and Hospital B) were investigated. After conducting an epidemiologic and environmental investigation, the water distribution systems (WDSs) were identified as the possible source of infection, as Legionella pneumophila serogroup 1 (Lp1) was isolated from both clinical and environmental samples. Patients received aerosol therapy with nebulizers during their hospitalization. Based on the results of the investigation, the hospitals’ infection control committees reviewed their policies for Legionnaires’ disease prevention and implemented control measures focusing on using sterile fluids for aerosol treatments.


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