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Environmental Surveillance of Legionella spp. in an Italian University Hospital Results of 10 Years of Analysis. WATER 2021. [DOI: 10.3390/w13162304] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
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.
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Jinna S, Gaikwad UN. Environmental surveillance of Legionella pneumophila in distal water supplies of a hospital for early identification & prevention of hospital-acquired legionellosis. Indian J Med Res 2018; 147:611-614. [PMID: 30168494 PMCID: PMC6118141 DOI: 10.4103/ijmr.ijmr_527_17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Indexed: 11/04/2022] Open
Abstract
Background & objectives Legionella pneumophila, a ubiquitous aquatic organism is found to be associated with the development of the community as well as hospital-acquired pneumonia. Diagnosing Legionella infection is difficult unless supplemented with, diagnostic laboratory testing and established evidence for its presence in the hospital environment. Hence, the present study was undertaken to screen the hospital water supplies for the presence of L. pneumophila to show its presence in the hospital environment further facilitating early diagnosis and prevention of hospital-acquired legionellosis. Methods Water samples and swabs from the inner side of the same water taps were collected from 30 distal water outlets present in patient care areas of a tertiary care hospital. The filtrate obtained from water samples as well as swabs were inoculated directly and after acid buffer treatment on plain and selective (with polymyxin B, cycloheximide and vancomycin) buffered charcoal yeast extract medium. The colonies grown were identified using standard methods and confirmed for L. pneumophila by latex agglutination test. Results About 6.66 per cent (2/30) distal water outlets sampled were found to be contaminated with L. pneumophila serotype 2-15. Isolation was better with swabs compared to water samples. Interpretation & conclusions The study showed the presence of L. pneumophila colonization of hospital water outlets at low levels. Periodic water sampling and active clinical surveillance in positive areas may be done to substantiate the evidence, to confirm or reject its role as a potential nosocomial pathogen in hospital environment.
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Affiliation(s)
- Shihail Jinna
- Department of Microbiology, All India Institute of Medical Sciences, Raipur, India
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Wright J, Ruseska I, Athar M, Corbett S, Costerton J. Legionella pneumophila Grows Adherent to Surfaces in vitro and in situ. Infect Control Hosp Epidemiol 2016. [DOI: 10.2307/30144209] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
AbstractLegionella pneumophila continues to play a role in both community- and nosocomially-acquired pneumonia. We investigated the ability of L pneumophila to adhere to various types of materials such as those found in the hospital air-cooling and potable water distribution systems. Through the use of a unique sampling apparatus, we were able to regularly acquire planktonic and sessile samples and determine the numbers of bacteria present in both populations, in vitro and in situ.Portions of these apparatuses could be aseptically removed for examination by scanning electron microscopy, or for the determination of the number of viable adherent L pneumophila. The number of bacteria present in each sample was determined by direct plate count, with presumptive L pneumophila colonies being positively identified by direct fluorescent antibody staining techniques.The results demonstrated that not only are legionellae capable of colonizing various metallic and nonmetallic surfaces but that they are preferentially found on surfaces. Surface-adherent bacteria may play a profound role as a reservoir of these potential pathogens in aquatic environments. Furthermore, these results suggest that any comprehensive legionella monitoring program must include not only water samples but also an examination of the adherent populations.
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Environmental Cultures and Hospital-Acquired Legionnaires' Disease: A 5-Year Prospective Study in 20 Hospitals in Catalonia, Spain. Infect Control Hosp Epidemiol 2015. [DOI: 10.1017/s019594170007750x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractObjective:To determine whether environmental cultures forLegionellaincrease the index of suspicion for legionnaires' disease (LD).Design:Five-year prospective study.Setting:Twenty hospitals in Catalonia, Spain.Methods:From 1994 to 1996, the potable water systems of 20 hospitals in Catalonia were tested forLegionella, Cases of hospital-acquired LD and availability of an “in-house”Legionellatest in the previous 4 years were assessed. After the hospitals were informed of the results of their water cultures, a prospective 5-year-study was conducted focusing on the detection of new cases of nosocomial legionellosis and the availability and use of Legionella testing.Results:Before environmental cultures were started, only one hospital had conducted active surveillance of hospital-acquired pneumonia and usedLegionellatests includingLegionellaurinary antigen in all pneumonia cases. Only one other hospital had used the latter test at all. In six hospitals,Legionellatests had been completely unavailable. Cases of nosocomial LD had been diagnosed in the previous 4 years in only two hospitals. During prospective surveillance, 12 hospitals (60%) usedLegionellaurinary antigen testing in house and 11 (55%) found cases of nosocomial legionellosis, representing 64.7% (11 of 17) of those with positive water cultures. Hospitals with negative water cultures did not find nosocomial LD.Conclusions:The environmental study increased the index of suspicion for nosocomial LD. The number of cases of nosocomial LD increased significantly during the prospective follow-up period, and most hospitals began using theLegionellaurinary antigen test in their laboratories.
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Stout JE, Muder RR, Mietzner S, Wagener MM, Perri MB, DeRoos K, Goodrich D, Arnold W, Williamson T, Ruark O, Treadway C, Eckstein EC, Marshall D, Rafferty ME, Sarro K, Page J, Jenkins R, Oda G, Shimoda KJ, Zervos MJ, Bittner M, Camhi SL, Panwalker AP, Donskey CJ, Nguyen MH, Holodniy M, Yu VL. Role of Environmental Surveillance in Determining the Risk of Hospital-Acquired Legionellosis: A National Surveillance Study With Clinical Correlations. Infect Control Hosp Epidemiol 2015; 28:818-24. [PMID: 17564984 DOI: 10.1086/518754] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 12/21/2006] [Indexed: 11/03/2022]
Abstract
Objective.Hospital-acquired Legionella pneumonia has a fatality rate of 28%, and the source is the water distribution system. Two prevention strategies have been advocated. One approach to prevention is clinical surveillance for disease without routine environmental monitoring. Another approach recommends environmental monitoring even in the absence of known cases of Legionella pneumonia. We determined the Legionella colonization status of water systems in hospitals to establish whether the results of environmental surveillance correlated with discovery of disease. None of these hospitals had previously experienced endemic hospital-acquired Legionella pneumonia.Design.Cohort study.Setting.Twenty US hospitals in 13 states.Interventions.Hospitals performed clinical and environmental surveillance for Legionella from 2000 through 2002. All specimens were shipped to the Special Pathogens Laboratory at the Veterans Affairs Pittsburgh Medical Center.Results.Legionella pneumophila and Legionella anisa were isolated from 14 (70%) of 20 hospital water systems. Of 676 environmental samples, 198 (29%) were positive for Legionella species. High-level colonization of the water system (30% or more of the distal outlets were positive for L. pneumophila) was demonstrated for 6 (43%) of the 14 hospitals with positive findings. L. pneumophila serogroup 1 was detected in 5 of these 6 hospitals, whereas 1 hospital was colonized with L. pneumophila serogroup 5. A total of 633 patients were evaluated for Legionella pneumonia from 12 (60%) of the 20 hospitals: 377 by urinary antigen testing and 577 by sputum culture. Hospital-acquired Legionella pneumonia was identified in 4 hospitals, all of which were hospitals with L. pneumophila serogroup 1 found in 30% or more of the distal outlets. No cases of disease due to other serogroups or species (L. anisa) were identified.Conclusion.Environmental monitoring followed by clinical surveillance was successful in uncovering previously unrecognized cases of hospital-acquired Legionella pneumonia.
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Affiliation(s)
- Janet E Stout
- VA Pittsburgh Healthcare System, Pittsburgh, PA, USA
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Sabrià M, Mòdol JM, Garcia-Nuñez M, Reynaga E, Pedro-Botet ML, Sopena N, Rey-Joly C. Environmental Cultures and Hospital-Acquired Legionnaires' Disease: A 5-Year Prospective Study in 20 Hospitals in Catalonia, Spain. Infect Control Hosp Epidemiol 2015; 25:1072-6. [PMID: 15636295 DOI: 10.1086/502346] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AbstractObjective:To determine whether environmental cultures forLegionellaincrease the index of suspicion for legionnaires' disease (LD).Design:Five-year prospective study.Setting:Twenty hospitals in Catalonia, Spain.Methods:From 1994 to 1996, the potable water systems of 20 hospitals in Catalonia were tested forLegionella, Cases of hospital-acquired LD and availability of an “in-house”Legionellatest in the previous 4 years were assessed. After the hospitals were informed of the results of their water cultures, a prospective 5-year-study was conducted focusing on the detection of new cases of nosocomial legionellosis and the availability and use of Legionella testing.Results:Before environmental cultures were started, only one hospital had conducted active surveillance of hospital-acquired pneumonia and usedLegionellatests includingLegionellaurinary antigen in all pneumonia cases. Only one other hospital had used the latter test at all. In six hospitals,Legionellatests had been completely unavailable. Cases of nosocomial LD had been diagnosed in the previous 4 years in only two hospitals. During prospective surveillance, 12 hospitals (60%) usedLegionellaurinary antigen testing in house and 11 (55%) found cases of nosocomial legionellosis, representing 64.7% (11 of 17) of those with positive water cultures. Hospitals with negative water cultures did not find nosocomial LD.Conclusions:The environmental study increased the index of suspicion for nosocomial LD. The number of cases of nosocomial LD increased significantly during the prospective follow-up period, and most hospitals began using theLegionellaurinary antigen test in their laboratories.
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Affiliation(s)
- Miquel Sabrià
- Infectious Diseases Section, Hospital Universitari Germans Trias i Pujol, Universitat Autonoma de Barcelona, Badalona, Spain
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Ditommaso S, Giacomuzzi M, Gentile M, Moiraghi AR, Zotti CM. Effective environmental sampling strategies for monitoring Legionella spp contamination in hot water systems. Am J Infect Control 2010; 38:344-9. [PMID: 20083326 DOI: 10.1016/j.ajic.2009.09.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Revised: 09/25/2009] [Accepted: 09/29/2009] [Indexed: 10/20/2022]
Abstract
BACKGROUND The prevention and control of legionellosis in hospital settings involves environmental sampling, among other measures. The data yielded by sampling constitute an important means of risk assessment and provide a valid basis on which to plan remedial (cleansing and disinfection) and preventive (maintenance) interventions. This retrospective study had 2 objectives: (1) to evaluate the utility of biofilm sampling at distal sites and (2) to identify an efficient environmental sampling strategy. METHODS Samples of hot water and biofilm were collected between June 1999 and March 2008 from 41 hospitals in Italy's Piemonte region. We analyzed results of the samples (water and biofilm) taken from the same site and results of the water samples taken from the recirculation loop and water samples taken from the distal sites during the same sampling run. RESULTS Microbiological analysis was performed on 3910 pairs of samples (water/biofilm). In 81% of the pairs, the results were concordant; in 17% of the pairs, Legionella was isolated only from the water samples, and in only 2% of the pairs was Legionella isolated from the biofilm sample alone. Data from 299 sampling runs show that 79% (236) of results from the water samples taken from the recirculation loop and water samples taken from the distal sites during the same sampling run were concordant, and 21% (63) were discordant. CONCLUSIONS Our findings suggest that hospitals could safely adopt a simpler (water sampling only without biofilm sampling) and more efficient (monitoring of the entire system through sampling of recirculation loop water) environmental sampling policy.
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Chien S, Fong CM, Hsueh J, Lee TM, Ben RJ, Chou ST, Lin HH, Shih HY, Lin Y, Tseng LR, Chiang CS. Epidemiological investigation of a case of nosocomial Legionnaires' disease in Taiwan: implications for routine environmental surveillance. Clin Microbiol Infect 2010; 16:761-3. [DOI: 10.1111/j.1469-0691.2009.02890.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Mavridou A, Smeti E, Mandilara G, Pappa O, Plakadonaki S, Grispou E, Polemis M. Prevalence study of Legionella spp. contamination in Greek hospitals. INTERNATIONAL JOURNAL OF ENVIRONMENTAL HEALTH RESEARCH 2008; 18:295-304. [PMID: 18668417 DOI: 10.1080/09603120801966035] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Water and swab samples were collected from 13 hospitals and analyzed for Legionella counts. Legionella was detected in eight out of 13 hospitals and in 22 of 130 water and swab-collected samples. A total of 72.7% of the strains were L. pneumophila ser. 1, 22.7% were L. pneumophila ser. 2-14, and 4.5% did not belong to any of these groups. AFLP typing of the L. pneumophila ser. 1 strains generated two distinguishable AFLP types. There was no significant correlation to the sample type with Legionella recovery. Legionella isolation was more likely to occur in the cooling towers than the water system. Water temperatures of 30-40 degrees C seem to favor Legionella growth. Of the 265 serum samples taken from the medical and technical staff for the control of IgG titre, 89.4% were negative, 7.2% were positive, and for 3.4% the result was doubtful. No association between IgG titre and maximum observed level of Legionella occurrence was detected.
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Affiliation(s)
- Athena Mavridou
- Technological Educational Institution of Athens Athens, Greece.
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Yu PY, Lin YE, Lin WR, Shih HY, Chuang YC, Ben RJ, Huang WK, Chen YS, Liu YC, Chang FY, Yen MY, Liu CC, Ko WC, Lin HH, Shi ZY. The high prevalence of Legionella pneumophila contamination in hospital potable water systems in Taiwan: implications for hospital infection control in Asia. Int J Infect Dis 2008; 12:416-20. [DOI: 10.1016/j.ijid.2007.11.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2007] [Revised: 11/19/2007] [Accepted: 11/22/2007] [Indexed: 11/15/2022] Open
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Exner M, Kramer A, Kistemann T, Gebel J, Engelhart S. Wasser als Infektionsquelle in medizinischen Einrichtungen, Prävention und Kontrolle. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz 2007; 50:302-11. [PMID: 17334890 DOI: 10.1007/s00103-007-0156-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
New epidemiological and microbiological investigations using molecular typing methods to link patient and environmental strains demonstrate a strong association between water-borne pathogens and nosocomial infections. Avoiding patient exposure to these pathogens results in a decreased incidence of water-borne nosocomial infections. There remains a tremendous potential to reduce hospital acquired infections previously viewed as inevitable and unavoidable through intervention and preventive measures. The characteristics of water application in health care facilities, the vulnerability of patients, the spectrum of relevant pathogens and their ecologic aspects, legal issues and important measures for prevention and control are discussed.
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Affiliation(s)
- M Exner
- Institut für Hygiene und Offentliche Gesundheit der Universität Bonn, Bonn, BRD.
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Squier CL, Stout JE, Krsytofiak S, McMahon J, Wagener MM, Dixon B, Yu VL. A proactive approach to prevention of health care-acquired Legionnaires' disease: the Allegheny County (Pittsburgh) experience. Am J Infect Control 2005; 33:360-7. [PMID: 16061143 DOI: 10.1016/j.ajic.2005.01.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2004] [Accepted: 01/19/2005] [Indexed: 10/25/2022]
Abstract
BACKGROUND The Allegheny County Health Department (ACHD) in Pennsylvania distributed the first guidelines for prevention and control of health care-acquired Legionnaires' disease (LD) by 1995. The proactive approach advocated in the guidelines differed notably from that of the Centers for Disease Control and Prevention (CDC) by recommending routine environmental testing of the hospital water distribution system even when cases of health care-acquired Legionnaires' disease had never been identified. OBJECTIVES Our purpose was to (1) evaluate the impact of the ACHD guidelines on the Legionella diagnostic and preventive practices of health care facilities in Allegheny and surrounding counties and (2) compare the incidence of health care-acquired LD before and after issuance of the ACHD guidelines. METHODS CDC case reports of LD from 1991 to 2001 were tabulated and compiled by the ACHD Infectious Disease Unit and the Association for Professionals in Infection Control and Epidemiology, Inc, Three Rivers Chapter. A survey was distributed to 110 hospitals and long-term care facilities in the region. The results were analyzed as occurring either in the preguideline period (1991-1994) or postguideline period (1995-2001). RESULTS A significant decrease in the number of health care-acquired cases was demonstrated between the preguideline (33%) and postguideline (9%) periods (P=.0001). In contrast, community-acquired cases increased from 67% pre guideline to 91% post guideline. A total of 71% of the facilities were colonized with Legionella. Disinfection of the water distribution system was initiated by 44% of facilities. Use of urinary antigen testing significantly increased from 40% pre guideline to 79% post guideline (P=.0001). CONCLUSIONS Health care-acquired LD declined significantly after the issuance of guidelines for prevention and control of health care-acquired LD. The decline was associated with health care facilities performing routine environmental monitoring of their water distribution systems followed by the initiation of disinfection methods if indicated. Two unanticipated benefits were (1) cases of LD in the community and long-term care facilities were uncovered as a result of increased availability of Legionella tests and (2) litigation and unfavorable publicity involving ACHD hospitals ceased.
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Affiliation(s)
- Cheryl L Squier
- Association for Professionals in Infection Control and Epidemiology, Three Rivers Chapter, and Veterans Administration Pittsburgh Healthcare System, Pennsylvania, USA
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Exner M, Kramer A, Lajoie L, Gebel J, Engelhart S, Hartemann P. Prevention and control of health care-associated waterborne infections in health care facilities. Am J Infect Control 2005; 33:S26-40. [PMID: 15940114 DOI: 10.1016/j.ajic.2005.04.002] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The current article is a review of the public health risks attributable to waterborne pathogens in health care. The consequences of health care-associated infections (HAIs) are discussed. Not only are Legionella spp involved in HAIs, but also Pseudomonas aeruginosa, other gram-negative microorganisms, fungi, and amoeba-associated bacteria. This is particularly noteworthy among immunocompromised patients. New prevention strategies and control measures brought about through advanced planning, facility remodelling and reconstruction, disinfection, and filtration have resulted in a significant reduction of the incidence of waterborne HAIs. The positive consequences of a comprehensive multibarrier approach including prevention and control programs in health care facilities are discussed. Environmental cultures are now integrated within the infection control program of some European countries. In high-risk areas, the application of disposable sterile point-of-use filters for faucets and shower heads appears to be the practice of choice to efficiently control waterborne pathogens and to prevent infections.
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Affiliation(s)
- M Exner
- Institute for Hygiene and Public Health, University of Bonn, Bonn, Germany.
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O'Neill E, Humphreys H. Surveillance of hospital water and primary prevention of nosocomial legionellosis: what is the evidence? J Hosp Infect 2005; 59:273-9. [PMID: 15749313 DOI: 10.1016/j.jhin.2004.09.031] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Hospital-acquired Legionnaires' disease may be sporadic or may occur as part of an outbreak. As Legionella spp. are ubiquitous in many water systems, it is not surprising that hospital water may be colonized with Legionella pneumophila and other species. However, there is some controversy about the relationship between the presence of legionella in hospital water systems and nosocomial legionellosis. Primary prevention, i.e. measures to prevent legionella in a hospital or healthcare facility with no previous documented cases of nosocomial legionellosis, includes heightened awareness of hospital-acquired Legionnaires' disease with appropriate laboratory diagnostic facilities, and ensuring that the water system is well designed and maintained in accordance with national standards, e.g. the circulating hot water is maintained above 55 degrees C. Secondary prevention, i.e. preventing further cases occurring when a case has been confirmed, should include an investigation to exclude the hospital water system as a source. However, the necessity to sample hospital water routinely to detect legionella outside of outbreaks, i.e. as a component of primary prevention, is unclear. Some studies demonstrate a clear link but others do not. Differences between the patient populations studied, the methods of laboratory diagnosis of clinical cases, the analysis of hospital water and differences in the design of hospital water systems may partly explain this. Whilst further research, probably in the form of multi-centred prospective trials, is needed to confirm the relationship between environmental legionella and hospital-acquired legionellosis, including establishing the relative importance of L. pneumophila group 1 vs. non-group 1 and other Legionella spp., each hospital should consider the spectrum of patients at particular risk locally. Centres with transplant units or other patients with significant immunosuppression should, in the interim, consider routine sampling for legionella in hospital water in addition to other control measures. Therefore, infection control teams must work closely with hospital engineering and technical services departments and hospital management, as well as ensuring that physicians and others have a heightened awareness of hospital-acquired legionellosis.
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Affiliation(s)
- E O'Neill
- Department of Clinical Microbiology, Royal College of Surgeons in Ireland, Dublin, Ireland.
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Stout JE, Yu VL. Experiences of the first 16 hospitals using copper-silver ionization for Legionella control: implications for the evaluation of other disinfection modalities. Infect Control Hosp Epidemiol 2003; 24:563-8. [PMID: 12940575 DOI: 10.1086/502251] [Citation(s) in RCA: 105] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND AND OBJECTIVES Hospital-acquired legionnaires' disease can be prevented by disinfection of hospital water systems. This study assessed the long-term efficacy of copper-silver ionization as a disinfection method in controlling Legionella in hospital water systems and reducing the incidence of hospital-acquired legionnaires' disease. A standardized, evidence-based approach to assist hospitals with decision making concerning the possible purchase of a disinfection system is presented. DESIGN The first 16 hospitals to install copper-silver ionization systems for Legionella disinfection were surveyed. Surveys conducted in 1995 and 2000 documented the experiences of the hospitals with maintenance of the system, contamination of water with Legionella, and occurrence of hospital-acquired legionnaires' disease. All were acute care hospitals with a mean of 435 beds. RESULTS All 16 hospitals reported cases of hospital-acquired legionnaires' disease prior to installing the copper-silver ionization system. Seventy-five percent had previously attempted other disinfection methods including superheat and flush, ultraviolet light, and hyperchlorination. By 2000, the ionization systems had been operational from 5 to 11 years. Prior to installation, 47% of the hospitals reported that more than 30% of distal water sites yielded Legionella. In 1995, after installation, 50% of the hospitals reported 0% positivity, and 43% still reported 0% in 2000. Moreover, no cases of hospital-acquired legionnaires' disease have occurred in any hospital since 1995. CONCLUSIONS This study represents the final step in a proposed 4-step evaluation process of disinfection systems that includes (1) demonstrated efficacy of Legionella eradication in vitro using laboratory assays, (2) anecdotal experiences in preventing legionnaires' disease in individual hospitals, (3) controlled studies in individual hospitals, and (4) validation in confirmatory reports from multiple hospitals during a prolonged time (5 to 11 years in this study). Copper-silver ionization is now the only disinfection modality to have fulfilled all four evaluation criteria.
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Affiliation(s)
- Janet E Stout
- Special Pathogens Laboratory, Veterans Affairs Medical Center, Pittsburg, Pennsylvania 15240, USA
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Craven DE. Progress in the battle against nosocomial legionnaires' disease: shedding light on shades of gray. Infect Control Hosp Epidemiol 2003; 24:560-2. [PMID: 12940574 DOI: 10.1086/502255] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Yamamoto N, Kubota T, Tateyama M, Koide M, Nakasone C, Tohyama M, Shinzato T, Higa F, Kusano N, Kawakami K, Saito A. Isolation of Legionella anisa from multiple sites of a hospital water system: the eradication of Legionellacontamination. J Infect Chemother 2003; 9:122-5. [PMID: 12825109 DOI: 10.1007/s10156-002-0228-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
For the prevention of nosocomial cases of legionellosis in the Ryukyu University Hospital neonatal wards, we examined nine shower units and a sink tap water unit for the presence of Legionella, over a 6-year period. We isolated Legionella-like organisms (LLO) from showerheads by culturing sediments from the water samples on buffered charcoal yeast extracts (BCYE). We used DNA-DNA hybridization to determine that the organisms were L. anisa. A fingerprinting technique called random amplified polymorphism DNA (RAPD) also showed that all the organisms were identical at the genome level. Replacement of the shower heads harboring colonies of L. anisa prevented further contamination. Nosocomial cases of legionellosis have not been reported from the wards during the period of this survey. This is the first description of the isolation of L. anisa from multiple sites within a hospital, and RAPD analysis suggests that these may be the spread of a single clone.
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Affiliation(s)
- Natsuo Yamamoto
- First Department of Internal Medicine, University of the Ryukyus, Okinawa, Japan.
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Sabria M, Yu VL. Hospital-acquired legionellosis: solutions for a preventable infection. THE LANCET. INFECTIOUS DISEASES 2002; 2:368-73. [PMID: 12144900 DOI: 10.1016/s1473-3099(02)00291-8] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Hospital-acquired Legionnaires' disease has been reported from many hospitals since the first outbreak in 1976. Although cooling towers were linked to the cases of Legionnaires' disease in the years after its discovery, potable water has been the environmental source for almost all reported hospital outbreaks. Microaspiration is the major mode of transmission in hospital-acquired Legionnaires' disease; showering is not a mode of transmission. Since the clinical manifestations are non-specific, and specialised laboratory testing is required, hospital-acquired legionellosis is easily underdiagnosed. Discovery of a single case of hospital-acquired Legionnaires' disease is an important sentinel of additional undiscovered cases. Routine environmental culture of the hospital water supply for legionella has proven to be an important strategy in prevention. Documentation of legionella colonisation in the water supply would increase physician index of suspicion for Legionnaires' disease and the necessity for in-house legionella test methods would be obvious. Legionella is a common commensal of large-building water supplies. Preventive maintenance is commonly recommended; unfortunately, this measure is ineffective in minimising legionella colonisation of building water supplies. Copper-silver ionisation systems have emerged as the most successful long-term disinfection method for hospital water disinfection systems. There is a need for public-health agencies to educate the public and media that discovery of cases identifies those hospitals as providers of superior care, and that such hospitals are not negligent.
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Affiliation(s)
- Miguel Sabria
- Hospital Universitario Germans Trias I Pujol and the Autonomous University of Barcelona, Badalona, Spain
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Stout JE, Yu VL. Legionella in the hospital water supply: a plea for decision making based on evidence-based medicine. Infect Control Hosp Epidemiol 2001; 22:670-2. [PMID: 11842984 DOI: 10.1086/501842] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Yu VL. Resolving the Controversy on Environmental Cultures for Legionella: A Modest Proposal. Infect Control Hosp Epidemiol 1998. [DOI: 10.2307/30142013] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Goetz AM, Stout JE, Jacobs SL, Fisher MA, Ponzer RE, Drenning S, Yu VL. Nosocomial legionnaires' disease discovered in community hospitals following cultures of the water system: seek and ye shall find. Am J Infect Control 1998; 26:8-11. [PMID: 9503106 DOI: 10.1016/s0196-6553(98)70054-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The reservoir for hospital-acquired legionnaires' disease is the water distribution system. The Allegheny County (Pa.) Health Department recommended environmental cultures for all health care facilities for the prevention of hospital-acquired Legionella infection including facilities with no known cases of legionnaires' disease. METHODS Environmental cultures of hot water tanks, faucets, and showerheads were performed in six health care facilities according to health department guidelines. If hot water tanks, faucets, or showerheads yielded Legionella, monitoring with Legionella culture and urinary antigen was performed for all cases of nosocomial pneumonia. RESULTS Legionella was isolated from the water distribution system in 83% (five of six) of facilities. Three facilities dropped out of the study; two decided to disinfect the water and one had no Legionella in the water system. The other three facilities all discovered cases of legionnaires' disease during the 1-year study period after introduction of Legionella testing. L. pneumophilia, serogroups 1, 3, and 5, caused 12 cases of hospital-acquired legionnaires' disease. Positive diagnostic tests included: 10 of 12 (83%) urinary antigen, 6 of 8 (75%) respiratory cultures, and 2 of 5 (40%) serology. Molecular typing confirmed that the source of infection was the water supply in two hospitals. CONCLUSION Routine environmental cultures for Legionella in the water distribution system are recommended even if the hospital had not previously recognized cases of hospital acquired legionnaires' disease. The Allegheny County Health Department guidelines were inexpensive to implement and resulted in the discovery of cases that would have otherwise been undiagnosed.
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Affiliation(s)
- A M Goetz
- Veterans Administration Medical Center and Legionella Study Group, Pittsburgh, PA 15240, USA
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Goetz A, Yu VL. Copper-silver ionization: cautious optimism for Legionella disinfection and implications for environmental culturing. Am J Infect Control 1997; 25:449-51. [PMID: 9437481 DOI: 10.1016/s0196-6553(97)90065-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Affiliation(s)
- J E Stout
- Veterans Affairs Medical Center and the University of Pittsburgh, PA 15240, USA
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Affiliation(s)
- D E Craven
- Department of Medicine, Boston University School of Medicine, USA
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Tablan OC, Anderson LJ, Arden NH, Breiman RF, Butler JC, McNeil MM. Guideline for Prevention of Nosocomial Pneumonia. Infect Control Hosp Epidemiol 1994. [DOI: 10.2307/30147436] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Matulonis U, Rosenfeld CS, Shadduck RK. Prevention of Legionella Infections in a Bone Marrow Transplant Unit: Multifaceted Approach to Decontamination of a Water System. Infect Control Hosp Epidemiol 1993. [DOI: 10.2307/30105124] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Yu VL, Liu Z, Stout JE, Goetz A. Legionella Disinfection of Water Distribution Systems: Principles, Problems, and Practice. Infect Control Hosp Epidemiol 1993. [DOI: 10.2307/30105123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Reinthaler FF, Sattler J, Schaffler-Dullnig K, Weinmayr B, Marth E. Comparative study of procedures for isolation and cultivation of Legionella pneumophila from tap water in hospitals. J Clin Microbiol 1993; 31:1213-6. [PMID: 8501221 PMCID: PMC262906 DOI: 10.1128/jcm.31.5.1213-1216.1993] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
For the isolation and cultivation of Legionella pneumophila from tap water in hospitals, we compared different media and selection techniques. A second part of the study compared the L. pneumophila yields from different water samples at identical sites. A total of 210 water samples (500 ml each) were collected from two selected sites in each of 21 hospitals. Warm water samples were collected after flow times of 0, 5, 10, and 15 min; in addition, one cold water sample was collected. Filtration was used to concentrate all samples. Following filtration, 0.1 and 1 ml each of untreated samples, heat-treated samples (3 min, 59 degrees C), and acid-treated samples (pH 2.2, 15 min) were spread onto the selective media MWY (SR 118; Oxoid) and BMPA alpha (SR 111; Oxoid), and samples from 12 hospitals were also spread onto GVPC medium (SR 152; Oxoid). A total of 72 (34%) of the 210 samples from 12 hospitals were positive. With respect to the positive Legionella cultures, there was no significant difference between the selective media MWY, BMPA alpha, and GVPC. With the BMPA alpha supplement, more samples were positive following heat treatment (P < 0.05) or acid treatment (P < 0.05) than without any further treatment. For the maximum yield of Legionella colonies with minimum additional microbial flora, acid treatment was the most effective, and by all methods, the GVPC supplement was the most selective. For routine water tests in hospitals for differentiating between systemic and local contamination, acid treatment of the concentrated samples, the use of different selective media, and the correct selection of sampling sites are recommended.
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Woo AH, Goetz A, Yu VL. Transmission of Legionella by respiratory equipment and aerosol generating devices. Chest 1992; 102:1586-90. [PMID: 1424896 DOI: 10.1378/chest.102.5.1586] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Affiliation(s)
- A H Woo
- Veterans Administration Medical Center, Pittsburgh 15240
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Nosocomial Legionnaires' disease: Clinical and radiographic patterns. Can J Infect Dis 1992; 3:253-60. [PMID: 22416200 DOI: 10.1155/1992/582736] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/1991] [Accepted: 08/09/1991] [Indexed: 11/17/2022] Open
Abstract
From 1981 to 1991, 55 patients (33 males, 22 females, mean age 58.6 years) with nosocomial Legionnaires' disease were studied. The mortality rate was 64%. One-half of the patients developed nosocomial Legionnaires' disease within three weeks of admission. A surprising clinical feature was the low rate of findings of consolidation on physical examination, despite the fact that 52% of patients had this finding on chest radiograph. More than one-half of patients had pre-existing lung disease, rendering a radiographic diagnosis of pneumonia due to Legionella pneumophila impossible in 16% of cases despite microbiological confirmation. Nineteen per cent of patients who had blood cultures done had a pathogen other than L pneumophila isolated, suggesting dual infection in at least some of the patients. When the clinical and radiographic findings were combined it was noted that 40% of patients had one of three patterns suggestive of nosocomial Legionnaires' disease: rapidly progressive pneumonia, lobar opacity and multiple peripheral opacities. However, in 60% of patients there were no distinctive features.
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Goetz A, Yu VL. Screening for nosocomial legionellosis by culture of the water supply and targeting of high-risk patients for specialized laboratory testing. Am J Infect Control 1991; 19:63-6. [PMID: 2053713 DOI: 10.1016/0196-6553(91)90040-j] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Marrie TJ, MacDonald S, Clarke K, Haldane D. Nosocomial legionnaires' disease: lessons from a four-year prospective study. Am J Infect Control 1991; 19:79-85. [PMID: 2053716 DOI: 10.1016/0196-6553(91)90043-c] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
We studied all cases of nosocomial pneumonia at our 800-bed tertiary care hospital from September 1983 to September 1987. Of the 813 cases of nosocomial pneumonia, 31 (3.8%) were definite (isolation of organism or fourfold rise in titer) and 21 (2.5%) were possible cases (single or stable antibody titer of greater than or equal to 1:256) of legionnaires' disease. The definite cases involved a more severe form of pneumonia and a significantly higher mortality rate--64% versus 14% (p less than 0.0009) compared with the possible cases. Despite attempted comprehensive surveillance, only four (13%) of the definite cases of legionnaires' disease were found that would not have been diagnosed if the study were not ongoing. The yield from adequate (4- to 6-week convalescent serum samples) serologic testing was 5%, whereas the yield from sputum culture was 11%. We conclude that targeted surveillance of immunosuppressed patients with nosocomial pneumonia by culture of respiratory tract secretions for Legionella pneumophila is adequate for monitoring for the presence of legionnaires' disease in a hospital.
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Affiliation(s)
- T J Marrie
- Department of Medicine, Dalhousie University, Halifax, Nova Scotia, Canada
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Vickers RM, Stout JE, Yu VL. Failure of a diagnostic monoclonal immunofluorescent reagent to detect Legionella pneumophila in environmental samples. Appl Environ Microbiol 1990; 56:2912-4. [PMID: 2275536 PMCID: PMC184863 DOI: 10.1128/aem.56.9.2912-2914.1990] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Three commercial diagnostic fluorescein-labeled antibodies, one monoclonal and two polyclonal, were compared to evaluate their abilities to detect Legionella pneumophila in environmental samples. The monoclonal conjugate failed to detect L. pneumophila in the 12 environmental samples studied by direct immunofluorescence. In contrast, the two polyclonal conjugates detected L. pneumophila in all 12 samples by both direct and indirect immunofluorescence. However, isolates recovered by culture from the 12 samples demonstrated equal immunofluorescence with all three conjugates. The reason for the failure of the monoclonal antibody to detect L. pneumophila in the environmental samples remains unknown. Laboratories considering the use of the monoclonal conjugate to screen environmental samples for L. pneumophila should be aware of this finding.
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Affiliation(s)
- R M Vickers
- Special Pathogens Section, Veterans Administration Medical Center, Pittsburgh, Pennsylvania
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Chow JW, Yu VL. Antibiotic studies in pneumonia. Pitfalls in interpretation and suggested soluions. Chest 1989; 96:453-6. [PMID: 2491417 DOI: 10.1378/chest.96.3.453] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Affiliation(s)
- J W Chow
- Department of Medicine, University of Pittsburgh School of Medicine 15261
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Wright JB, Ruseska I, Athar MA, Corbett S, Costerton JW. Legionella pneumophila grows adherent to surfaces in vitro and in situ. Infect Control Hosp Epidemiol 1989; 10:408-15. [PMID: 2794466 DOI: 10.1086/646062] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Legionella pneumophila continues to play a role in both community- and nosocomially-acquired pneumonia. We investigated the ability of L pneumophila to adhere to various types of materials such as those found in the hospital air-cooling and portable water distribution systems. Through the use of a unique sampling apparatus, we were able to regularly acquire planktonic and sessile samples and determine the numbers of bacteria present in both populations, in vitro and in situ. Portions of these apparatuses could be aseptically removed for examination by scanning electron microscopy, or for the determination of the number of viable adherent L pneumophila. The number of bacteria present in each sample was determined by direct plate count, with presumptive L pneumophila colonies being positively identified by direct fluorescent antibody staining techniques. The results demonstrated that not only are legionellae capable of colonizing various metallic and nonmetallic surfaces but that they are preferentially found on surfaces. Surface-adherent bacteria may play a profound role as a reservoir of these potential pathogens in aquatic environments. Furthermore, these results suggest that any comprehensive legionella monitoring program must include not only water samples but also an examination of the adherent populations.
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Affiliation(s)
- J B Wright
- Department of Biological Sciences, University of Calgary, Alberta, Canada
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