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Xi H, Ross KE, Hinds J, Molino PJ, Whiley H. Efficacy of chlorine-based disinfectants to control Legionella within premise plumbing systems. WATER RESEARCH 2024; 259:121794. [PMID: 38824796 DOI: 10.1016/j.watres.2024.121794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 06/04/2024]
Abstract
Legionella is an opportunistic waterborne pathogen that causes Legionnaires' disease. It poses a significant public health risk, especially to vulnerable populations in health care facilities. It is ubiquitous in manufactured water systems and is transmitted via inhalation or aspiration of aerosols/water droplets generated from water fixtures (e.g., showers and hand basins). As such, the effective management of premise plumbing systems (building water systems) in health care facilities is essential for reducing the risk of Legionnaires' disease. Chemical disinfection is a commonly used control method and chlorine-based disinfectants, including chlorine, chloramine, and chlorine dioxide, have been used for over a century. However, the effectiveness of these disinfectants in premise plumbing systems is affected by various interconnected factors that can make it challenging to maintain effective disinfection. This systematic literature review identifies all studies that have examined the factors impacting the efficacy and decay of chlorine-based disinfectant within premise plumbing systems. A total of 117 field and laboratory-based studies were identified and included in this review. A total of 20 studies directly compared the effectiveness of the different chlorine-based disinfectants. The findings from these studies ranked the typical effectiveness as follows: chloramine > chlorine dioxide > chlorine. A total of 26 factors were identified across 117 studies as influencing the efficacy and decay of disinfectants in premise plumbing systems. These factors were sorted into categories of operational factors that are changed by the operation of water devices and fixtures (such as stagnation, temperature, water velocity), evolving factors which are changed in-directly (such as disinfectant concentration, Legionella disinfectant resistance, Legionella growth, season, biofilm and microbe, protozoa, nitrification, total organic carbon(TOC), pH, dissolved oxygen(DO), hardness, ammonia, and sediment and pipe deposit) and stable factors that are not often changed(such as disinfectant type, pipe material, pipe size, pipe age, water recirculating, softener, corrosion inhibitor, automatic sensor tap, building floor, and construction activity). A factor-effect map of each of these factors and whether they have a positive or negative association with disinfection efficacy against Legionella in premise plumbing systems is presented. It was also found that evaluating the effectiveness of chlorine disinfection as a water risk management strategy is further complicated by varying disinfection resistance of Legionella species and the form of Legionella (culturable/viable but non culturable, free living/biofilm associated, intracellular replication within amoeba hosts). Future research is needed that utilises sensors and other approaches to measure these key factors (such as pH, temperature, stagnation, water age and disinfection residual) in real time throughout premise plumbing systems. This information will support the development of improved models to predict disinfection within premise plumbing systems. The findings from this study will inform the use of chlorine-based disinfection within premise plumbing systems to reduce the risk of Legionnaires disease.
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Affiliation(s)
- Hao Xi
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia; Enware Pty Ltd, Caringbah, NSW, Australia.
| | - Kirstin E Ross
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Jason Hinds
- ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, Australia; Enware Pty Ltd, Caringbah, NSW, Australia
| | | | - Harriet Whiley
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia; ARC Training Centre for Biofilm Research and Innovation, Flinders University, Bedford Park, SA, Australia
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Farina C, Cacciabue E, Averara F, Ferri N, Vailati F, Del Castillo G, Serafini A, Fermi B, Doniselli N, Pezzoli F. Water Safety Plan, Monochloramine Disinfection and Extensive Environmental Sampling Effectively Control Legionella and Other Waterborne Pathogens in Nosocomial Settings: The Ten-Year Experience of an Italian Hospital. Microorganisms 2023; 11:1794. [PMID: 37512966 PMCID: PMC10384652 DOI: 10.3390/microorganisms11071794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 07/10/2023] [Accepted: 07/12/2023] [Indexed: 07/30/2023] Open
Abstract
Legionella contamination control is crucial in healthcare settings where patients suffer an increased risk of disease and fatal outcome. To ensure an effective management of this health hazard, the accurate application of a hospital-specific Water Safety Plan (WSP), the choice of a suitable water disinfection system and an extensive monitoring program are required. Here, the ten-year experience of an Italian hospital is reported: since its commissioning, Legionellosis risk management has been entrusted to a multi-disciplinary Working Group, applying the principles of the World Health Organization's WSP. The disinfection strategy to prevent Legionella and other waterborne pathogens relies on the treatment of domestic hot water with a system ensuring the in situ production and dosage of monochloramine. An average of 250 samples/year were collected and analyzed to allow an accurate assessment of the microbiological status of water network. With the aim of increasing the monitoring sensitivity, in addition to the standard culture method, an optimized MALDI-ToF MS-based strategy was applied, allowing the identification of Legionella species and other relevant opportunistic pathogens. Data collected so far confirmed the effectiveness of this multidisciplinary approach: the fraction of positive samples never overcame 1% on a yearly basis and Legionnaires' Disease cases never occurred.
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Affiliation(s)
- Claudio Farina
- Microbiology and Virology Laboratory, ASST "Papa Giovanni XXIII", 24127 Bergamo, Italy
| | - Eleonora Cacciabue
- Health Care Coordination Offices, ASST "Papa Giovanni XXIII", 24127 Bergamo, Italy
| | - Franca Averara
- Department of Health Care Professions, ASST "Papa Giovanni XXIII", 24127 Bergamo, Italy
| | - Nadia Ferri
- Microbiology and Virology Laboratory, ASST "Papa Giovanni XXIII", 24127 Bergamo, Italy
| | - Francesca Vailati
- Microbiology and Virology Laboratory, ASST "Papa Giovanni XXIII", 24127 Bergamo, Italy
| | | | | | - Beatrice Fermi
- Sanipur S.p.A., 25020 Flero, Italy
- ESCMID Study Group for Legionella Infections (ESGLI), 4001 Basel, Switzerland
| | - Nicola Doniselli
- Sanipur S.p.A., 25020 Flero, Italy
- ESCMID Study Group for Legionella Infections (ESGLI), 4001 Basel, Switzerland
| | - Fabio Pezzoli
- Health Care Coordination Offices, ASST "Papa Giovanni XXIII", 24127 Bergamo, Italy
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Gea-Izquierdo E, Gil-de-Miguel Á, Rodríguez-Caravaca G. Legionella pneumophila Risk from Air–Water Cooling Units Regarding Pipe Material and Type of Water. Microorganisms 2023; 11:microorganisms11030638. [PMID: 36985212 PMCID: PMC10053303 DOI: 10.3390/microorganisms11030638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 02/27/2023] [Accepted: 02/28/2023] [Indexed: 03/06/2023] Open
Abstract
Legionellosis is a respiratory disease related to environmental health. There have been manifold studies of pipe materials, risk installations and legionellosis without considering the type of transferred water. The objective of this study was to determine the potential development of the causative agent Legionella pneumophila regarding air–water cooling units, legislative compliance, pipe material and type of water. Forty-four hotel units in Andalusia (Spain) were analysed with respect to compliance with Spanish health legislation for the prevention of legionellosis. The chi-square test was used to explain the relationship between material–water and legislative compliance, and a biplot of the first two factors was generated. Multiple correspondence analysis (MCA) was performed on the type of equipment, legislative compliance, pipe material and type of water, and graphs of cases were constructed by adding confidence ellipses by categories of the variables. Pipe material–type of water (p value = 0.29; p < 0.05) and legislative compliance were not associated (p value = 0.15; p < 0.05). Iron, stainless steel, and recycled and well water contributed the most to the biplot. MCA showed a global pattern in which lead, iron and polyethylene were well represented. Confidence ellipses around categories indicated significant differences among categories. Compliance with Spanish health legislation regarding the prevention and control of legionellosis linked to pipe material and type of water was not observed.
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Affiliation(s)
- Enrique Gea-Izquierdo
- Preventive Medicine and Public Health, Rey Juan Carlos University, 28922 Madrid, Spain
- Maria Zambrano Program, European Union, Spain
- Correspondence:
| | - Ángel Gil-de-Miguel
- Preventive Medicine and Public Health, Rey Juan Carlos University, 28922 Madrid, Spain
- CIBER of Respiratory Diseases (CIBERES), Instituto de Salud Carlos III, 28029 Madrid, Spain
| | - Gil Rodríguez-Caravaca
- Preventive Medicine and Public Health, Rey Juan Carlos University, 28922 Madrid, Spain
- Department of Preventive Medicine, Hospital Universitario Fundación Alcorcón, Universidad Rey Juan Carlos, 28922 Madrid, Spain
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Proctor C, Garner E, Hamilton KA, Ashbolt NJ, Caverly LJ, Falkinham JO, Haas CN, Prevost M, Prevots DR, Pruden A, Raskin L, Stout J, Haig SJ. Tenets of a holistic approach to drinking water-associated pathogen research, management, and communication. WATER RESEARCH 2022; 211:117997. [PMID: 34999316 PMCID: PMC8821414 DOI: 10.1016/j.watres.2021.117997] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 05/10/2023]
Abstract
In recent years, drinking water-associated pathogens that can cause infections in immunocompromised or otherwise susceptible individuals (henceforth referred to as DWPI), sometimes referred to as opportunistic pathogens or opportunistic premise plumbing pathogens, have received considerable attention. DWPI research has largely been conducted by experts focusing on specific microorganisms or within silos of expertise. The resulting mitigation approaches optimized for a single microorganism may have unintended consequences and trade-offs for other DWPI or other interests (e.g., energy costs and conservation). For example, the ecological and epidemiological issues characteristic of Legionella pneumophila diverge from those relevant for Mycobacterium avium and other nontuberculous mycobacteria. Recent advances in understanding DWPI as part of a complex microbial ecosystem inhabiting drinking water systems continues to reveal additional challenges: namely, how can all microorganisms of concern be managed simultaneously? In order to protect public health, we must take a more holistic approach in all aspects of the field, including basic research, monitoring methods, risk-based mitigation techniques, and policy. A holistic approach will (i) target multiple microorganisms simultaneously, (ii) involve experts across several disciplines, and (iii) communicate results across disciplines and more broadly, proactively addressing source water-to-customer system management.
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Affiliation(s)
- Caitlin Proctor
- Department of Agricultural and Biological Engineering, Division of Environmental and Ecological Engineering, Purdue University, West Lafayette, IN, USA
| | - Emily Garner
- Wadsworth Department of Civil & Environmental Engineering, West Virginia University, Morgantown, WV, USA
| | - Kerry A Hamilton
- School of Sustainable Engineering and the Built Environment and The Biodesign Centre for Environmental Health Engineering, Arizona State University, Tempe, AZ, USA
| | - Nicholas J Ashbolt
- Faculty of Science and Engineering, Southern Cross University, Gold Coast. Queensland, Australia
| | - Lindsay J Caverly
- Department of Pediatrics, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Charles N Haas
- Department of Civil, Architectural & Environmental Engineering, Drexel University, Philadelphia, PA, USA
| | - Michele Prevost
- Department of Civil, Geological and Mining Engineering, Polytechnique Montreal, Montreal, Quebec, Canada
| | - D Rebecca Prevots
- Epidemiology Unit, Laboratory of Clinical Immunology and Microbiology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, USA
| | - Amy Pruden
- Department of Civil & Environmental Engineering, Virginia Tech, Blacksburg, VA USA
| | - Lutgarde Raskin
- Department of Civil & Environmental Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Janet Stout
- Department of Civil & Environmental Engineering, University of Pittsburgh, and Special Pathogens Laboratory, Pittsburgh, PA, USA
| | - Sarah-Jane Haig
- Department of Civil & Environmental Engineering, and Department of Environmental & Occupational Health, University of Pittsburgh, Pittsburgh, PA, USA.
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Bavari S, Mirkalantari S, Masjedian Jazi F, Darban-Sarokhalil D, Golnari Marani B. Risk assessment and quantitative measurement along with monitoring of Legionella in hospital water sources. New Microbes New Infect 2022; 45:100948. [PMID: 35399198 PMCID: PMC8984627 DOI: 10.1016/j.nmni.2021.100948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/21/2021] [Accepted: 12/20/2021] [Indexed: 11/25/2022] Open
Abstract
Legionella spp. as a causative agent of Legionnaires' disease (LD) and an opportunistic pathogen creates a public health problem. Isolation and quantification of this bacteria from clinic water sources are essential for hazard appraisal and sickness avoidance. This study aimed at risk assessment and quantitative measurement along with Legionella monitoring in educational hospital water sources in Tehran, Iran. A cross-sectional study was carried out in 1 year. The conventional culture method was used in this study to isolate Legionella from water samples. The polymerase chain reaction (PCR) technique was used to confirm the identity of the isolates and ensure that they were all Legionella. Quantitative PCR (qPCR) was used to determine the count of bacteria, and HeLa cell culture was used to determine the invasion of isolates. A total of 100 water samples were collected and inoculated on GVPC (glycine, vancomycin, polymyxin, and cycloheximide) agar; 12 (12%) and 42 (42%) cases were culture and PCR positive, respectively. Percentage of Legionella presence in PCR-positive samples by the qPCR method in <103 GU/L, in about 103 and lower than 104 GU/L, and in 104 GU/L was 40.47 (17 cases), 4.76% (two cases), and 54.76% (23 cases), respectively. Invasion analysis revealed that five and four isolates had invaded HeLa cells more than twice and equally, respectively, and the others had a lower invasion than the reference strain. The findings revealed that the spread of LD in hospitals was linked to the water system. Given the importance of nosocomial infections in the medical community, establishing a hospital water monitoring system is the most effective way to control these infections, particularly Legionella infections.
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Yui S, Karia K, Ali S, Muzslay M, Wilson P. Thermal disinfection at suboptimal temperature of Pseudomonas aeruginosa biofilm on copper pipe and shower hose materials. J Hosp Infect 2021; 117:103-110. [PMID: 34428505 DOI: 10.1016/j.jhin.2021.08.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/13/2021] [Accepted: 08/17/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Hospital-acquired infections caused by Pseudomonas aeruginosa have been linked to contaminated shower systems in health care. Thermal disinfection, whereby colonized outlets are flushed with existing hot water supplies, is a commonly used method to disinfect contaminated systems. Temperatures of 60°C are recommended for inactivation of P. aeruginosa; however, this is often not achievable at outlets. AIM To investigate whether thermal disinfection at a suboptimal temperature (58°C) can effectively eradicate planktonic P. aeruginosa and biofilm adherent on copper piping and shower hoses. Exposure times of up to 60 min and efficacy of repeated cycles were evaluated. METHODS A type culture and an environmental strain of P. aeruginosa isolated from a hospital shower were tested. Planktonic bacteria and biofilm adhered to sections of copper pipe and shower hoses were exposed to water at 58°C for up to 60 min. Biofilms were tested with static water, flushing water and repeated cycles of disinfection. Remaining viable bacteria after disinfection were enumerated. FINDINGS Planktonic P. aeruginosa remained viable after up to 60 min of thermal disinfection. With static water, biofilm was removed from copper piping after 15 min, but remained viable in shower hoses for up to 60 min. With thermal flushing, biofilm was fully eradicated from copper piping after 2 min, but remained viable on shower hoses. Repeated cycles did not shorten thermal disinfection exposure times. CONCLUSION Thermal disinfection at 58°C was effective at eliminating biofilm on copper; however, biofilm on shower hoses remained viable after 60 min of exposure.
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Affiliation(s)
- S Yui
- Environmental Research Laboratory, University College London Hospital, London, UK.
| | - K Karia
- Environmental Research Laboratory, University College London Hospital, London, UK
| | - S Ali
- Environmental Research Laboratory, University College London Hospital, London, UK
| | - M Muzslay
- Environmental Research Laboratory, University College London Hospital, London, UK
| | - P Wilson
- Environmental Research Laboratory, University College London Hospital, London, UK
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Salinas MB, Fenoy S, Magnet A, Vaccaro L, Gomes TD, Hurtado C, Ollero D, Valdivieso E, Del Águila C, Pozuelo MJ, Izquierdo F. Are pathogenic Legionella non-pneumophila a common bacteria in Water Distribution Networks? WATER RESEARCH 2021; 196:117013. [PMID: 33813251 DOI: 10.1016/j.watres.2021.117013] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/16/2021] [Accepted: 03/04/2021] [Indexed: 05/22/2023]
Abstract
The present study analyzes at the national level, the presence of circulating Legionella in the artificial aquatic systems of different facilities of all of them state-owned centers throughout Spain for 12 months. 1754 water samples from various state-owned centers were collected from January to December 2014. Samples were collected from the cooling towers and evaporative condensers (CTC), and water distribution networks such as domestic hot water (DHW), cold water for human consumption (CW), sprinkler irrigation systems (SIS), fire sprinkler systems (FSS), and water from decorative fountains (DF). All these facilities are considered, according to current regulations, as potential amplifying systems for bacteria and possible sources of infection by the generation of droplets and aerosols. The isolation and counting of Legionella in water samples was carried out using microbiological culture following the international normative UNE-EN-ISO 11,731:2007 (ISO 11,731:1998) and UNE-EN ISO 8199:2008 (ISO 8199:2005).The quantification of Legionella colonization, the annual distribution, and the geographical distribution of the Legionella isolates recovered in the water were analyzed. Besides, molecular techniques were used for the characterization of the Legionella non-pneumophila isolates. Legionella was recovered from 15.79% of the analyzed water samples. High colonization was more frequently detected in water samples from CTC, DHW, CW, and DF. Regarding the geographic distribution, positive samples of Legionella were obtained in 14 of the 18 Spanish locations analyzed. Legionella non-pneumophila was the most prevalent and was isolated from water samples from 13 different geographical locations (72%). Legionella anisa and Legionella jordanis were the most frequently non-pneumophila species isolated. Legionella donaldsonii was isolated for the first time in the water distribution networks in Spain. Legionella pneumophila sg 2-14 was detected in 13 locations and Legionella pneumophila sg 1 in 11 locations. Therefore, our study concludes that the presence of Legionella pneumophila and Legionella non-pneumophila species in these systems can be a potential threat to public health and should be examined thoroughly with complementary techniques, such as molecular techniques as a screen for routine diagnosis.
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Affiliation(s)
- Mireya Beatriz Salinas
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Soledad Fenoy
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Angela Magnet
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Lucianna Vaccaro
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Thiago Ds Gomes
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Carolina Hurtado
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Dolores Ollero
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Elizabeth Valdivieso
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Carmen Del Águila
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - María José Pozuelo
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España
| | - Fernando Izquierdo
- Facultad de Farmacia, Universidad San Pablo-CEU, CEU Universities, Urbanización Montepríncipe, 28660 Boadilla del Monte, Madrid, España.
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Causes, Factors, and Control Measures of Opportunistic Premise Plumbing Pathogens—A Critical Review. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11104474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
This review critically analyses the chemical and physical parameters that influence the occurrence of opportunistic pathogens in the drinking water distribution system, specifically in premise plumbing. A comprehensive literature review reveals significant impacts of water age, disinfectant residual (type and concentration), temperature, pH, and pipe materials. Evidence suggests that there is substantial interplay between these parameters; however, the dynamics of such relationships is yet to be elucidated. There is a correlation between premise plumbing system characteristics, including those featuring water and energy conservation measures, and increased water quality issues and public health concerns. Other interconnected issues exacerbated by high water age, such as disinfectant decay and reduced corrosion control efficiency, deserve closer attention. Some common features and trends in the occurrence of opportunistic pathogens have been identified through a thorough analysis of the available literature. It is proposed that the efforts to reduce or eliminate their incidence might best focus on these common features.
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9
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Chambers ST, Slow S, Scott-Thomas A, Murdoch DR. Legionellosis Caused by Non- Legionella pneumophila Species, with a Focus on Legionella longbeachae. Microorganisms 2021; 9:291. [PMID: 33572638 PMCID: PMC7910863 DOI: 10.3390/microorganisms9020291] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 01/23/2021] [Accepted: 01/26/2021] [Indexed: 12/13/2022] Open
Abstract
Although known as causes of community-acquired pneumonia and Pontiac fever, the global burden of infection caused by Legionella species other than Legionella pneumophila is under-recognised. Non-L. pneumophila legionellae have a worldwide distribution, although common testing strategies for legionellosis favour detection of L. pneumophila over other Legionella species, leading to an inherent diagnostic bias and under-detection of cases. When systematically tested for in Australia and New Zealand, L. longbeachae was shown to be a leading cause of community-acquired pneumonia. Exposure to potting soils and compost is a particular risk for infection from L. longbeachae, and L. longbeachae may be better adapted to soil and composting plant material than other Legionella species. It is possible that the high rate of L. longbeachae reported in Australia and New Zealand is related to the composition of commercial potting soils which, unlike European products, contain pine bark and sawdust. Genetic studies have demonstrated that the Legionella genomes are highly plastic, with areas of the chromosome showing high levels of recombination as well as horizontal gene transfer both within and between species via plasmids. This, combined with various secretion systems and extensive effector repertoires that enable the bacterium to hijack host cell functions and resources, is instrumental in shaping its pathogenesis, survival and growth. Prevention of legionellosis is hampered by surveillance systems that are compromised by ascertainment bias, which limits commitment to an effective public health response. Current prevention strategies in Australia and New Zealand are directed at individual gardeners who use potting soils and compost. This consists of advice to avoid aerosols generated by the use of potting soils and use masks and gloves, but there is little evidence that this is effective. There is a need to better understand the epidemiology of L. longbeachae and other Legionella species in order to develop effective treatment and preventative strategies globally.
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Affiliation(s)
- Stephen T. Chambers
- Department of Pathology and Biomedical Science, University of Otago, Christchurch 8011, New Zealand; (S.S.); (A.S.-T.); (D.R.M.)
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Quero S, Párraga-Niño N, Garcia-Núñez M, Pedro-Botet ML, Gavaldà L, Mateu L, Sabrià M, Mòdol JM. The impact of pipeline changes and temperature increase in a hospital historically colonised with Legionella. Sci Rep 2021; 11:1916. [PMID: 33479467 PMCID: PMC7820426 DOI: 10.1038/s41598-021-81625-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 01/01/2021] [Indexed: 01/25/2023] Open
Abstract
Healthcare-related Legionnaires’ disease has a devastating impact on high risk patients, with a case fatality rate of 30–50%. Legionella prevention and control in hospitals is therefore crucial. To control Legionella water colonisation in a hospital setting we evaluated the effect of pipeline improvements and temperature increase, analysing 237 samples over a 2-year period (first year: 129, second year: 108). In the first year, 25.58% of samples were positive for Legionella and 16.67% for amoeba. Assessing the distance of the points analysed from the hot water tank, the most distal points presented higher proportion of Legionella colonisation and lower temperatures (nearest points: 6.4% colonised, and temperature 61.4 °C; most distal points: 50% and temperature 59.1 °C). After the first year, the hot water system was repaired and the temperature stabilised. This led to a dramatic reduction in Legionella colonisation, which was negative in all the samples analysed; however, amoeba colonisation remained stable. This study shows the importance of keeping the temperature stable throughout the circuit, at around 60 °C. Special attention should be paid to the most distal points of the circuit; a fall in temperature at these weak points would favour the colonisation and spread of Legionella, because amoeba (the main Legionella reservoir) are not affected by temperature.
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Affiliation(s)
- S Quero
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain. .,CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain. .,Institut d'Investigació i Innovació Parc Taulí, I3PT, Parc Taulí, 1, 08208, Sabadell, Barcelona, Spain.
| | - N Párraga-Niño
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain
| | - M Garcia-Núñez
- Infectious Diseases Unit, Fundació Institut d'Investigació Germans Trias I Pujol, Carretera de Can Ruti, Camí de les Escoles s/n, 08916, Badalona, Barcelona, Spain.,CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.,Institut d'Investigació i Innovació Parc Taulí, I3PT, Parc Taulí, 1, 08208, Sabadell, Barcelona, Spain
| | - M L Pedro-Botet
- CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.,Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
| | - L Gavaldà
- Hospital Universitari de Bellvitge-IDIBELL, Feixa Llarga, s/n., 08907, L'Hospitalet de Llobregat, Barcelona, Spain
| | - L Mateu
- Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
| | - M Sabrià
- CIBER de Enfermedades Respiratorias, CIBERES, Av. de Monforte de Lemos, 3-5, 28029, Madrid, Spain.,Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
| | - J M Mòdol
- Hospital Universitari Germans Trias i Pujol, Carretera de Canyet, s/n, 08916, Badalona, Barcelona, Spain
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Brigmon RL, Turick CE, Knox AS, Burckhalter CE. The Impact of Storms on Legionella pneumophila in Cooling Tower Water, Implications for Human Health. Front Microbiol 2020; 11:543589. [PMID: 33362725 PMCID: PMC7758282 DOI: 10.3389/fmicb.2020.543589] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 11/02/2020] [Indexed: 12/03/2022] Open
Abstract
At the U.S. Department of Energy’s Savannah River Site (SRS) in Aiken, SC, cooling tower water is routinely monitored for Legionella pneumophila concentrations using a direct fluorescent antibody (DFA) technique. Historically, 25–30 operating SRS cooling towers have varying concentrations of Legionella in all seasons of the year, with patterns that are unpredictable. Legionellosis, or Legionnaires’ disease (LD), is a pneumonia caused by Legionella bacteria that thrive both in man-made water distribution systems and natural surface waters including lakes, streams, and wet soil. Legionnaires’ disease is typically contracted by inhaling L. pneumophila, most often in aerosolized mists that contain the bacteria. At the SRS, L. pneumophila is typically found in cooling towers ranging from non-detectable up to 108 cells/L in cooling tower water systems. Extreme weather conditions contributed to elevations in L. pneumophila to 107–108 cells/L in SRS cooling tower water systems in July–August 2017. L. pneumophila concentrations in Cooling Tower 785-A/2A located in SRS A-Area, stayed in the 108 cells/L range despite biocide addition. During this time, other SRS cooling towers did not demonstrate this L. pneumophila increase. No significant difference was observed in the mean L. pneumophila mean concentrations for the towers (p < 0.05). There was a significant variance observed in the 285-2A/A Tower L. pneumophila results (p < 0.05). Looking to see if we could find “effects” led to model development by analyzing 13 months of water chemistry and microbial data for the main factors influencing the L. pneumophila concentrations in five cooling towers for this year. It indicated chlorine and dissolved oxygen had a significant impact (p < 0.0002) on cooling tower 785A/2A. Thus, while the variation in the log count data for the A-area tower is statistically greater than that of the other four towers, the average of the log count data for the A-Area tower was in line with that of the other towers. It was also observed that the location of 785A/2A and basin resulted in more debris entering the system during storm events. Our results suggest that future analyses should evaluate the impact of environmental conditions and cooling tower design on L. pneumophila water concentrations and human health.
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Affiliation(s)
- Robin L Brigmon
- Savannah River National Laboratory, Environmental Science and Biotechnology Group, Aiken, SC, United States
| | - Charles E Turick
- Savannah River National Laboratory, Environmental Science and Biotechnology Group, Aiken, SC, United States
| | - Anna S Knox
- Savannah River National Laboratory, Environmental Science and Biotechnology Group, Aiken, SC, United States
| | - Courtney E Burckhalter
- Savannah River National Laboratory, Environmental Science and Biotechnology Group, Aiken, SC, United States
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12
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Exner M, Bhattacharya S, Gebel J, Goroncy-Bermes P, Hartemann P, Heeg P, Ilschner C, Kramer A, Ling ML, Merkens W, Oltmanns P, Pitten F, Rotter M, Schmithausen RM, Sonntag HG, Steinhauer K, Trautmann M. Chemical disinfection in healthcare settings: critical aspects for the development of global strategies. GMS HYGIENE AND INFECTION CONTROL 2020; 15:Doc36. [PMID: 33520601 PMCID: PMC7818848 DOI: 10.3205/dgkh000371] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Chemical disinfection is an indispensable means of preventing infection. This holds true for healthcare settings, but also for all other settings where transmission of pathogens poses a potential health risk to humans and/or animals. Research on how to ensure effectiveness of disinfectants and the process of disinfection, as well as on when, how and where to implement disinfection precautions is an ongoing challenge requiring an interdisciplinary team effort. The valuable resources of active substances used for disinfection must be used wisely and their interaction with the target organisms and the environment should be evaluated and monitored closely, if we are to reliable reap the benefits of disinfection in future generations. In view of the global threat of communicable diseases and emerging and re-emerging pathogens and multidrug-resistant pathogens, the relevance of chemical disinfection is continually increasing. Although this consensus paper pinpoints crucial aspects for strategies of chemical disinfection in terms of the properties of disinfectant agents and disinfection practices in a particularly vulnerable group and setting, i.e., patients in healthcare settings, it takes a comprehensive, holistic approach to do justice to the complexity of the topic of disinfection.
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Affiliation(s)
- Martin Exner
- Institute of Hygiene and Public Health, Bonn University, Bonn, Germany
| | | | - Jürgen Gebel
- Institute of Hygiene and Public Health, Bonn University, Bonn, Germany
| | | | - Philippe Hartemann
- Departement Environnement et Santé Publique S.E.R.E.S., Faculté de Médecine, Nancy, France
| | - Peter Heeg
- Institute of Medical Microbiology and Hygiene, University of Tübingen, Germany
| | - Carola Ilschner
- Institute of Hygiene and Public Health, Bonn University, Bonn, Germany
| | - Axel Kramer
- Institute of Hygiene and Environmental Medicine, University Medicine Greifswald, Germany
| | - Moi Lin Ling
- Infection Prevention & Control, Singapore General Hospital, Singapore
| | | | | | - Frank Pitten
- IKI – Institut für Krankenhaushygiene & Infektionskontrolle GmbH, Gießen, Germany
| | | | | | - Hans-Günther Sonntag
- Institute of Hygiene and Medical Microbiology, University of Heidelberg, Germany
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13
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Marchesi I, Paduano S, Frezza G, Sircana L, Vecchi E, Zuccarello P, Oliveri Conti G, Ferrante M, Borella P, Bargellini A. Safety and Effectiveness of Monochloramine Treatment for Disinfecting Hospital Water Networks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17176116. [PMID: 32842654 PMCID: PMC7503937 DOI: 10.3390/ijerph17176116] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/12/2020] [Accepted: 08/20/2020] [Indexed: 11/16/2022]
Abstract
The formation of potentially carcinogenic N-nitrosamines, associated with monochloramine, requires further research due to the growing interest in using this biocide for the secondary disinfection of water in public and private buildings. The aim of our study was to evaluate the possible formation of N-nitrosamines and other toxic disinfection by-products (DBPs) in hospital hot water networks treated with monochloramine. The effectiveness of this biocide in controlling Legionella spp. contamination was also verified. For this purpose, four different monochloramine-treated networks, in terms of the duration of treatment and method of biocide injection, were investigated. Untreated hot water, municipal cold water and, limited to N-nitrosamines analysis, hot water treated with chlorine dioxide were analyzed for comparison. Legionella spp. contamination was successfully controlled without any formation of N-nitrosamines. No nitrification or formation of the regulated DBPs, such as chlorites and trihalomethanes, occurred in monochloramine-treated water networks. However, a stable formulation of hypochlorite, its frequent replacement with a fresh product, and the routine monitoring of free ammonia are recommended to ensure a proper disinfection. Our study confirms that monochloramine may be proposed as an effective and safe strategy for the continuous disinfection of building plumbing systems, preventing vulnerable individuals from being exposed to legionellae and dangerous DBPs.
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Affiliation(s)
- Isabella Marchesi
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (S.P.); (G.F.); (P.B.); (A.B.)
- Correspondence: ; Tel.: +39-059-2055460
| | - Stefania Paduano
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (S.P.); (G.F.); (P.B.); (A.B.)
| | - Giuseppina Frezza
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (S.P.); (G.F.); (P.B.); (A.B.)
| | - Luca Sircana
- University Hospital Policlinico of Modena, Largo del Pozzo 71, 41124 Modena, Italy; (L.S.); (E.V.)
| | - Elena Vecchi
- University Hospital Policlinico of Modena, Largo del Pozzo 71, 41124 Modena, Italy; (L.S.); (E.V.)
| | - Pietro Zuccarello
- Environmental and Food Hygiene Laboratory (LIAA), Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, 95123 Catania, Italy; (P.Z.); (G.O.C.); (M.F.)
| | - Gea Oliveri Conti
- Environmental and Food Hygiene Laboratory (LIAA), Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, 95123 Catania, Italy; (P.Z.); (G.O.C.); (M.F.)
| | - Margherita Ferrante
- Environmental and Food Hygiene Laboratory (LIAA), Department of Medical and Surgical Sciences and Advanced Technologies “G.F. Ingrassia”, University of Catania, 95123 Catania, Italy; (P.Z.); (G.O.C.); (M.F.)
| | - Paola Borella
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (S.P.); (G.F.); (P.B.); (A.B.)
| | - Annalisa Bargellini
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy; (S.P.); (G.F.); (P.B.); (A.B.)
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14
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Paduano S, Marchesi I, Casali ME, Valeriani F, Frezza G, Vecchi E, Sircana L, Romano Spica V, Borella P, Bargellini A. Characterisation of Microbial Community Associated with Different Disinfection Treatments in Hospital hot Water Networks. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:E2158. [PMID: 32213901 PMCID: PMC7143765 DOI: 10.3390/ijerph17062158] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/20/2020] [Accepted: 03/22/2020] [Indexed: 12/16/2022]
Abstract
Many disinfection treatments can be adopted for controlling opportunistic pathogens in hospital water networks in order to reduce infection risk for immunocompromised patients. Each method has limits and strengths and it could determine modifications on bacterial community. The aim of our investigation was to study under real-life conditions the microbial community associated with different chemical (monochloramine, hydrogen peroxide, chlorine dioxide) and non-chemical (hyperthermia) treatments, continuously applied since many years in four hot water networks of the same hospital. Municipal cold water, untreated secondary, and treated hot water were analysed for microbiome characterization by 16S amplicon sequencing. Cold waters had a common microbial profile at genera level. The hot water bacterial profiles differed according to treatment. Our results confirm the effectiveness of disinfection strategies in our hospital for controlling potential pathogens such as Legionella, as the investigated genera containing opportunistic pathogens were absent or had relative abundances ≤1%, except for non-tuberculous mycobacteria, Sphingomonas, Ochrobactrum and Brevundimonas. Monitoring the microbial complexity of healthcare water networks through 16S amplicon sequencing is an innovative and effective approach useful for Public Health purpose in order to verify possible modifications of microbiota associated with disinfection treatments.
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Affiliation(s)
- Stefania Paduano
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.P.); (I.M.); (M.E.C.); (G.F.); (P.B.)
| | - Isabella Marchesi
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.P.); (I.M.); (M.E.C.); (G.F.); (P.B.)
| | - Maria Elisabetta Casali
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.P.); (I.M.); (M.E.C.); (G.F.); (P.B.)
- University Hospital Policlinico of Modena, 41124 Modena, Italy; (E.V.); (L.S.)
| | - Federica Valeriani
- Department of Movement, Human and Health Sciences, Public Health Unit, University of Rome ‘Foro Italico’, 00135 Rome, Italy; (F.V.); (V.R.S.)
| | - Giuseppina Frezza
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.P.); (I.M.); (M.E.C.); (G.F.); (P.B.)
| | - Elena Vecchi
- University Hospital Policlinico of Modena, 41124 Modena, Italy; (E.V.); (L.S.)
| | - Luca Sircana
- University Hospital Policlinico of Modena, 41124 Modena, Italy; (E.V.); (L.S.)
| | - Vincenzo Romano Spica
- Department of Movement, Human and Health Sciences, Public Health Unit, University of Rome ‘Foro Italico’, 00135 Rome, Italy; (F.V.); (V.R.S.)
| | - Paola Borella
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.P.); (I.M.); (M.E.C.); (G.F.); (P.B.)
| | - Annalisa Bargellini
- Department of Biomedical, Metabolic and Neural Sciences, Section of Public Health, University of Modena and Reggio Emilia, 41125 Modena, Italy; (S.P.); (I.M.); (M.E.C.); (G.F.); (P.B.)
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15
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Advances in Legionella Control by a New Formulation of Hydrogen Peroxide and Silver Salts in a Hospital Hot Water Network. Pathogens 2019; 8:pathogens8040209. [PMID: 31671765 PMCID: PMC6963979 DOI: 10.3390/pathogens8040209] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/24/2019] [Accepted: 10/25/2019] [Indexed: 01/22/2023] Open
Abstract
Legionella surveillance is an important issue in public health, linked to the severity of disease and the difficulty associated with eradicating this bacterium from the water environment. Different treatments are suggested to reduce Legionella risk, however long-term studies of their efficiency are lacking. This study focused on the activity of a new formulation of hydrogen peroxide and silver salts, WTP828, in the hospital hot water network (HWN) to contain Legionella contamination during two years of treatment. The effectiveness of WTP828 was tested measuring physical-chemical and microbiological parameters such as Legionella, Pseudomonas aeruginosa (P. aeruginosa), and a heterotopic plate count (HPC) at 36 °C. Legionella isolates were identified by serotyping and genotyping. WTP 828 induced a reduction in Legionella–positive sites (60% to 36%) and contamination levels (2.12 to 1.7 log10 CFU/L), with isolates belonging to L. pneumophila SG1 (ST1 and ST104), L. anisa and L. rubrilucens widely distributed in HWN. No relevant contamination was found for other parameters tested. The long-term effect of WTP828 on Legionella containment suggest the easy and safe application of this disinfectant, that combined with knowledge of building characteristics, an adequate environmental monitoring and risk assessment plan, become the key elements in preventing Legionella contamination and exposure.
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16
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Vincenti S, de Waure C, Raponi M, Teleman AA, Boninti F, Bruno S, Boccia S, Damiani G, Laurenti P. Environmental surveillance of Legionella spp. colonization in the water system of a large academic hospital: Analysis of the four-year results on the effectiveness of the chlorine dioxide disinfection method. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 657:248-253. [PMID: 30543973 DOI: 10.1016/j.scitotenv.2018.12.036] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 11/16/2018] [Accepted: 12/04/2018] [Indexed: 06/09/2023]
Abstract
The prevention of Legionella colonization of water systems is one of the goals of hospital management. Among chemical disinfection methods, chlorine dioxide (ClO2) has been largely used to control Legionella spp. in water systems. We performed a retrospective study to analyse data deriving from the surveillance plan of the water system in a large academic hospital in Rome (Italy) during the period August 2011 and August 2018. We collected the data deriving from the routine water samples used to monitor Legionella spp. colonization. Data from the water samples collected from 163 selected sampling points (hot water tanks, the return loop and distal outlets) was analysed using a life table analysis in order to investigate the duration of the effectiveness of the ClO2 method in eradicating Legionella spp. The colonization of the water sample by Legionella spp. was considered as the outcome. Our results show that in 81,59% of the sampling points Legionella spp. were never detected at four years of follow up. Chemical and physical characteristics of the water were also compared between the samples which were positive for Legionella spp. and those which were not. No association was found between these factors. The knowledge of the duration over time of the effectiveness of the ClO2 disinfection method could support decision-making processes in the framework of Risk Management activities in hospitals. Future studies could also be conducted in hospitals to compare the long-term cost-effectiveness of different Legionella spp. colonization prevention methods.
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Affiliation(s)
- Sara Vincenti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Chiara de Waure
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Matteo Raponi
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy.
| | - Adele Anna Teleman
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Federica Boninti
- Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Stefania Bruno
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Stefania Boccia
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Gianfranco Damiani
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy
| | - Patrizia Laurenti
- Institute of Public Health, Section of Hygiene, Università Cattolica del Sacro Cuore, Largo Francesco Vito 1, 00168 Roma, Italy; Fondazione Policlinico Universitario A. Gemelli IRCCS, Largo Francesco Vito 1, 00168 Roma, Italy
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17
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Sanli NO. Evaluation of biocidal efficacy of Chloramine T trihydrate on planktonic and sessile bacteria in a model cooling tower water system. WATER SCIENCE AND TECHNOLOGY : A JOURNAL OF THE INTERNATIONAL ASSOCIATION ON WATER POLLUTION RESEARCH 2019; 79:526-536. [PMID: 30924807 DOI: 10.2166/wst.2019.076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A model cooling tower system was experimentally seeded with Legionella pneumophila and real industrial cooling tower (CT) water has been run at the closest to full-scale system operating conditions. The water/biofilm samples were taken from the model system monthly, and the effectiveness of the different concentrations of Chloramine T trihydrate biocide was evaluated in terms of its ability to control both planktonic/sessile microbial populations. Although Chloramine T is a recommended commercial formulation for disinfecting CTs, there is a lack of published data on the efficacy of this compound against both planktonic and sessile populations in the cooling tower. Biocide response in both sessile/planktonic bacteria counts varied according to months. Tested biocide concentrations provided the clean tower conditions by reducing the concentration of heterotrophic plate count (HPC) below <104 cfu mL-1, L. pneumophila <10 cfu mL-1 and of adenosine triphosphate (ATP) values <300 relative light units (RLU), after 1, 3 and 24 h of exposure, during a 6-month period. There were no statistically significant differences in efficacy between concentrations in terms of reduction in the number of bacteria, decrease in ATP value and viability. The results revealed that Chloramine T can effectively control biofouling in cooling systems according to the limit values of the successful control program.
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Affiliation(s)
- Nazmiye Ozlem Sanli
- Section of Fundamental and Industrial Microbiology, Department of Biology, Faculty of Science, Istanbul University, Vezneciler, Fatih, 34134 Istanbul, Turkey E-mail: ;
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18
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Oh Y, Noga R, Shanov V, Ryu H, Chandra H, Yadav B, Yadav J, Chae S. Electrically heatable carbon nanotube point-of-use filters for effective separation and in-situ inactivation of Legionella pneumophila. CHEMICAL ENGINEERING JOURNAL (LAUSANNE, SWITZERLAND : 1996) 2019; 366:21-26. [PMID: 31275054 PMCID: PMC6604856 DOI: 10.1016/j.cej.2019.02.054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Despite municipal chlorination and secondary disinfection, opportunistic waterborne pathogens (e.g., Legionella spp.) persist in public and private water distribution systems. As a potential source of healthcare-acquired infections, this warrants development of novel pathogen removal and inactivation systems. In this study, electrically heatable carbon nanotube (CNT) point-of-use (POU) filters have been designed to remove and inactivate Legionella pneumophila in water. The CNT/polymer composite membranes effectively removed Legionella (> 99.99%) (i.e., below detection limit) and were able to inactive them on the membrane surface at 100% efficiency within 60 s using ohmic heating at 20 V. The novel POU filters could be used as a final barrier to provide efficient rejection of pathogens and thereby simultaneously eliminate microorganisms in public and private water supplies.
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Affiliation(s)
- Yoontaek Oh
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, U.S.A
| | - Ryan Noga
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, U.S.A
| | - Vesselin Shanov
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, U.S.A
| | - Hodon Ryu
- National Risk Management Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH 45268, U.S.A
| | - Harish Chandra
- Microbial Pathogenesis and Immunotoxicology Laboratory, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267, U.S.A
| | - Brijesh Yadav
- Microbial Pathogenesis and Immunotoxicology Laboratory, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267, U.S.A
| | - Jagjit Yadav
- Microbial Pathogenesis and Immunotoxicology Laboratory, Department of Environmental Health, University of Cincinnati, Cincinnati, OH 45267, U.S.A
| | - Soryong Chae
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, OH 45221, U.S.A
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19
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Bonetta S, Pignata C, Bonetta S, Meucci L, Giacosa D, Marino E, Gorrasi I, Gilli G, Carraro E. Effectiveness of a neutral electrolysed oxidising water (NEOW) device in reducing Legionella pneumophila in a water distribution system: A comparison between culture, qPCR and PMA-qPCR detection methods. CHEMOSPHERE 2018; 210:550-556. [PMID: 30029147 DOI: 10.1016/j.chemosphere.2018.07.053] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 07/09/2018] [Accepted: 07/10/2018] [Indexed: 05/22/2023]
Abstract
Disinfection of hot water systems is critical for reducing Legionnaires' disease in high-risk buildings. The use of neutral electrolysed oxidising water (NEOW) is a promising method for the control of microorganisms in hot water systems. However, full-scale evaluations of the efficacy of NEOW devices to control Legionella pneumophila are currently lacking. The aim of this study was to assess the effectiveness of a NEOW device in reducing L. pneumophila in a hotel water network. Water samples (n = 67) were collected from different sites of a hotel distribution system before and after the installation of the NEOW device at the 1st, 4th, 8th and 12th week. Detection of L. pneumophila was performed comparing culture, qPCR and PMA-qPCR methods. Total bacterial counts (22 °C and 37 °C), Pseudomonas spp. and physico-chemical parameters were also monitored. The NEOW treatment resulted in a reduction of the amount of L. pneumophila positive samples (-32%) and of the number of heavily contaminated points (>104 CFU/L and >103 CFU/L) (-100% and -96%, respectively). Treatment maintained L. pneumophila at low levels (<102 CFU/L), which do not require specific intervention measures. The effectiveness of the disinfection system was also confirmed by PMA-qPCR (p < 0.001). The use of PMA resulted in a signal decrease in almost all samples upon the disinfection treatment. The NEOW disinfection device appears to be a promising approach to reduce the colonisation of hot water systems by L. pneumophila; however, further investigations are needed to ascertain its efficiency over longer time periods.
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Affiliation(s)
- Sara Bonetta
- Department of Public Health and Pediatrics, University of Torino, Piazza Polonia 94, 10126, Torino, Italy.
| | - Cristina Pignata
- Department of Public Health and Pediatrics, University of Torino, Piazza Polonia 94, 10126, Torino, Italy
| | - Silvia Bonetta
- Department of Public Health and Pediatrics, University of Torino, Piazza Polonia 94, 10126, Torino, Italy
| | - Lorenza Meucci
- Società Metropolitana Acque Torino S.P.A, C.so XI Febbraio 14, 10152, Torino, Italy
| | - Donatella Giacosa
- Società Metropolitana Acque Torino S.P.A, C.so XI Febbraio 14, 10152, Torino, Italy
| | - Elena Marino
- Società Metropolitana Acque Torino S.P.A, C.so XI Febbraio 14, 10152, Torino, Italy
| | - Ilaria Gorrasi
- Department of Public Health and Pediatrics, University of Torino, Piazza Polonia 94, 10126, Torino, Italy
| | - Giorgio Gilli
- Department of Public Health and Pediatrics, University of Torino, Piazza Polonia 94, 10126, Torino, Italy
| | - Elisabetta Carraro
- Department of Public Health and Pediatrics, University of Torino, Piazza Polonia 94, 10126, Torino, Italy
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20
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Trnková K, Kotrbancová M, Špaleková M, Fulová M, Boledovičová J, Vesteg M. MALDI-TOF MS analysis as a useful tool for an identification of Legionella pneumophila, a facultatively pathogenic bacterium interacting with free-living amoebae: A case study from water supply system of hospitals in Bratislava (Slovakia). Exp Parasitol 2017; 184:97-102. [PMID: 29225047 DOI: 10.1016/j.exppara.2017.12.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/20/2017] [Accepted: 12/05/2017] [Indexed: 01/30/2023]
Abstract
Legionellae, i.e. Legionella pneumophila, are human bacterial hydrophilic facultative pathogens causing pneumonia (Legionnaires' disease). Free-living amoebae (FLA) can serve as natural hosts and thus as reservoirs of many amoebae-resistant bacteria. An encysted amoeba can contribute to the resistance of intracellular L. pneumophila to various chemical and physical treatments. Humans can be infected by droplets containing bacteria from an environmental source or human-made devices such as shower heads, bathtubs, air-conditioning units or whirlpools. In this study, we were investigating the presence of FLA and L. pneumophila in plumbing systems of healthcare facilities in Bratislava (Slovakia) by standard diagnostic methods, while the presence of L. pneumophila was verified also by MALDI-TOF MS (matrix-assisted laser desorption/ionization time-of-flight mass spectrometry) analysis. The results showed the occurrence of L. pneumophila and FLA in 62.26% and 66.4% of samples taken from four paediatric clinics, respectively. Both standard methods and MALDI-TOF MS showed comparable results and they can be successfully applied for the identification of L. pneumophila strains in environmental samples. Our approach could be useful for further monitoring, prevention and decreasing risk of Legionella infection also in other hospitals.
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Affiliation(s)
- Katarína Trnková
- Department of the Environment, Faculty of Natural Sciences, Matej Bel University, Tajovského 55, 974 01 Banská Bystrica, Slovakia.
| | - Martina Kotrbancová
- Institute of Epidemiology, Faculty of Medicine, Comenius University Bratislava, Špitálska 24, 813 72 Bratislava, Slovakia.
| | - Margita Špaleková
- Institute of Epidemiology, Faculty of Medicine, Comenius University Bratislava, Špitálska 24, 813 72 Bratislava, Slovakia.
| | - Miriam Fulová
- Institute of Epidemiology, Faculty of Medicine, Comenius University Bratislava, Špitálska 24, 813 72 Bratislava, Slovakia.
| | - Jana Boledovičová
- Children's Faculty Hospital and Clinic, Limbová 1, 833 40, Bratislava, Slovakia.
| | - Matej Vesteg
- Department of Biology and Ecology, Faculty of Natural Sciences, Matej Bel University, Tajovského 40, 974 01 Banská Bystrica, Slovakia.
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Prussin AJ, Schwake DO, Marr LC. Ten Questions Concerning the Aerosolization and Transmission of Legionella in the Built Environment. BUILDING AND ENVIRONMENT 2017; 123:684-695. [PMID: 29104349 PMCID: PMC5665586 DOI: 10.1016/j.buildenv.2017.06.024] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Legionella is a genus of pathogenic Gram-negative bacteria responsible for a serious disease known as legionellosis, which is transmitted via inhalation of this pathogen in aerosol form. There are two forms of legionellosis: Legionnaires' disease, which causes pneumonia-like symptoms, and Pontiac fever, which causes influenza-like symptoms. Legionella can be aerosolized from various water sources in the built environment including showers, faucets, hot tubs/swimming pools, cooling towers, and fountains. Incidence of the disease is higher in the summertime, possibly because of increased use of cooling towers for air conditioning systems and differences in water chemistry when outdoor temperatures are higher. Although there have been decades of research related to Legionella transmission, many knowledge gaps remain. While conventional wisdom suggests that showering is an important source of exposure in buildings, existing measurements do not provide strong support for this idea. There has been limited research on the potential for Legionella transmission through heating, ventilation, and air conditioning (HVAC) systems. Epidemiological data suggest a large proportion of legionellosis cases go unreported, as most people who are infected do not seek medical attention. Additionally, controlled laboratory studies examining water-to-air transfer and source tracking are still needed. Herein, we discuss ten questions that spotlight current knowledge about Legionella transmission in the built environment, engineering controls that might prevent future disease outbreaks, and future research that is needed to advance understanding of transmission and control of legionellosis.
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Affiliation(s)
- Aaron J. Prussin
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
- Corresponding Author:
| | - David Otto Schwake
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Linsey C. Marr
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA, 24061, USA
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Application of Hydrogen Peroxide as an Innovative Method of Treatment for Legionella Control in a Hospital Water Network. Pathogens 2017; 6:pathogens6020015. [PMID: 28420075 PMCID: PMC5488649 DOI: 10.3390/pathogens6020015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 12/14/2022] Open
Abstract
Objectives: To evaluate the effectiveness of hydrogen peroxide (HP) use as a disinfectant in the hospital water network for the control of Legionella spp. colonization. Methods: Following the detection of high levels of Legionella contamination in a 136-bed general hospital water network, an HP treatment of the hot water supply (25 mg/L) was adopted. During a period of 34 months, the effectiveness of HP on Legionella colonization was assessed. Legionella was isolated in accordance with ISO-11731 and identification was carried out by sequencing of the mip gene. Results: Before HP treatment, L. pneumophila sg 2–15 was isolated in all sites with a mean count of 9950 ± 8279 cfu/L. After one-month of HP treatment, we observed the disappearance of L. pneumophila 2–15, however other Legionella species previously not seen were found; Legionellapneumophila 1 was isolated in one out of four sampling sites (2000 cfu/L) and other non-pneumophila species were present in all sites (mean load 3000 ± 2887 cfu/L). Starting from September 2013, HP treatment was modified by adding food-grade polyphosphates, and in the following months, we observed a progressive reduction of the mean load of all species (p < 0.05), resulting in substantial disappearance of Legionella colonization. Conclusion: Hydrogen peroxide demonstrated good efficacy in controlling Legionella. Although in the initial phases of treatment it appeared unable to eliminate all Legionella species, by maintaining HP levels at 25 mg/L and adding food-grade polyphosphates, a progressive and complete control of colonization was obtained.
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