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Kunz JM, Hannapel E, Vander Kelen P, Hils J, Hoover ER, Edens C. Effects of the COVID-19 Pandemic on Legionella Water Management Program Performance across a United States Lodging Organization. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:6885. [PMID: 37835155 PMCID: PMC10572137 DOI: 10.3390/ijerph20196885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 09/21/2023] [Accepted: 09/27/2023] [Indexed: 10/15/2023]
Abstract
Legionella, the bacterium that causes Legionnaires' disease, can grow and spread in building water systems and devices. The COVID-19 pandemic impacted building water systems through reductions in water usage. Legionella growth risk factors can be mitigated through control measures, such as flushing, to address stagnation, as part of a water management program (WMP). A national lodging organization (NLO) provided WMP data, including Legionella environmental testing results for periods before and during the pandemic. The statistical analysis revealed an increased risk of water samples testing positive for Legionella during the pandemic, with the greatest increase in risk observed at the building's cold-water entry test point. Sample positivity did not vary by season, highlighting the importance of year-round Legionella control activities. The NLO's flushing requirements may have prevented an increased risk of Legionella growth during the pandemic. However, additional control measures may be needed for some facilities that experience Legionella detections. This analysis provides needed evidence for the use of flushing to mitigate the impacts of building water stagnation, as well as the value of routine Legionella testing for WMP validation. Furthermore, this report reinforces the idea that WMPs remain the optimal tool to reduce the risk of Legionella growth and spread in building water systems.
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Affiliation(s)
- Jasen M. Kunz
- Division of Foodborne, Waterborne, and Environmental Diseases, National Center for Emerging and Zoonotic Infectious Diseases, Centers for Disease Control and Prevention, Mailstop H24-11, 1600 Clifton Road, Atlanta, GA 30333, USA
| | - Elizabeth Hannapel
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Mailstop H24-6, 1600 Clifton Road, Atlanta, GA 30333, USA; (E.H.); (C.E.)
| | - Patrick Vander Kelen
- Division of Environmental Health Science and Practice, National Center for Environmental Health, Centers for Disease Control and Prevention, Mailstop S106-5, 4770 Buford Highway, Atlanta, GA 30341, USA; (P.V.K.); (E.R.H.)
| | - Janie Hils
- Division of Environmental Health Science and Practice, National Center for Environmental Health, Centers for Disease Control and Prevention, Mailstop S106-5, 4770 Buford Highway, Atlanta, GA 30341, USA; (P.V.K.); (E.R.H.)
- Oak Ridge Institute for Science and Education, P.O. Box 117, Oak Ridge, TN 37830, USA
| | - Edward Rickamer Hoover
- Division of Environmental Health Science and Practice, National Center for Environmental Health, Centers for Disease Control and Prevention, Mailstop S106-5, 4770 Buford Highway, Atlanta, GA 30341, USA; (P.V.K.); (E.R.H.)
| | - Chris Edens
- Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Mailstop H24-6, 1600 Clifton Road, Atlanta, GA 30333, USA; (E.H.); (C.E.)
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Radziminski C, White P. Cooling tower Legionella pneumophila surveillance results: Vancouver, Canada, 2021. JOURNAL OF WATER AND HEALTH 2023; 21:313-328. [PMID: 37338312 PMCID: wh_2023_154 DOI: 10.2166/wh.2023.154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2023]
Abstract
Cooling towers have been linked to Legionnaires' disease cases and outbreaks. Legionella pneumophila results (from a culture-based method) are presented for 557 cooling towers across the City of Vancouver, Canada for 2021. Results of 10 CFU/mL or greater (defined as exceedances) were reported for 30 cooling towers (5.4%), including six >1,000 CFU/mL, and L. pneumophila serogroup 1 (sg1) was identified in 17 of these cooling towers (out of 28 with serogroup-level analysis). The data indicate highly localised Legionella issues, with exceedances concentrated within 16 facilities, including two hospitals. In the 3 months preceding each cooling tower exceedance, the nearest municipal water sampling station had a free chlorine residual of at least 0.46 mg/L and a temperature of <20 °C. There was not a statistically significant correlation between the L. pneumophila concentration of a cooling tower in exceedance and the municipal water free chlorine residual, temperature, pH, turbidity or conductivity. There was a statistically significant negative correlation between the concentrations of L. pneumophila sg1 and other L. pneumophila serogroups in cooling towers. This unique dataset underscores the pivotal role of building owners and managers in preventing the growth of Legionella bacteria and the value of regulations to verify operations and maintenance practices.
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Affiliation(s)
- Christopher Radziminski
- City of Vancouver, Development, Buildings & Licensing, 515 W 10th Avenue, Vancouver, BC V5Z 4A8, Canada E-mail:
| | - Phillip White
- City of Vancouver, Development, Buildings & Licensing, 515 W 10th Avenue, Vancouver, BC V5Z 4A8, Canada E-mail:
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Nisar MA, Ross KE, Brown MH, Bentham R, Best G, Whiley H. Detection and quantification of viable but non-culturable Legionella pneumophila from water samples using flow cytometry-cell sorting and quantitative PCR. Front Microbiol 2023; 14:1094877. [PMID: 36793878 PMCID: PMC9922708 DOI: 10.3389/fmicb.2023.1094877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Accepted: 01/03/2023] [Indexed: 02/03/2023] Open
Abstract
Legionella pneumophila is a waterborne pathogen and, as the causative agent of Legionnaires' disease, a significant public health concern. Exposure to environmental stresses, and disinfection treatments, promotes the formation of resistant and potentially infectious viable but non-culturable (VBNC) Legionella. The management of engineered water systems to prevent Legionnaires' disease is hindered by the presence of VBNC Legionella that cannot be detected using the standard culture (ISO11731:2017-05) and quantitative polymerase reaction (ISO/TS12869:2019) methods. This study describes a novel method to quantify VBNC Legionella from environmental water samples using a "viability based flow cytometry-cell sorting and qPCR" (VFC + qPCR) assay. This protocol was then validated by quantifying the VBNC Legionella genomic load from hospital water samples. The VBNC cells were unable to be cultured on Buffered Charcoal Yeast Extract (BCYE) agar; however, their viability was confirmed through their ATP activity and ability to infect amoeba hosts. Subsequently, an assessment of the ISO11731:2017-05 pre-treatment procedure demonstrated that acid or heat treatment cause underestimation of alive Legionella population. Our results showed that these pre-treatment procedures induce culturable cells to enter a VBNC state. This may explain the observed insensitivity and lack of reproducibility often observed with the Legionella culture method. This study represents the first time that flow cytometry-cell sorting in conjunction with a qPCR assay has been used as a rapid and direct method to quantify VBNC Legionella from environmental sources. This will significantly improve future research evaluating Legionella risk management approaches for the control of Legionnaires' disease.
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Affiliation(s)
- Muhammad Atif Nisar
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Kirstin E. Ross
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Melissa H. Brown
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Richard Bentham
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia
| | - Giles Best
- College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia,Flow Cytometry Facility, Flinders University, Bedford Park, SA, Australia
| | - Harriet Whiley
- College of Science and Engineering, Flinders University, Bedford Park, SA, Australia,*Correspondence: Harriet Whiley, ✉
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Gamage SD, Jinadatha C, Coppin JD, Kralovic SM, Bender A, Ambrose M, Decker BK, DeVries AS, Goto M, Kowalskyj O, Maistros AL, Rizzo V, Simbartl LA, Watson RJ, Roselle GA. Factors That Affect Legionella Positivity in Healthcare Building Water Systems from a Large, National Environmental Surveillance Initiative. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:11363-11373. [PMID: 35929739 DOI: 10.1021/acs.est.2c02194] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Legionella growth in healthcare building water systems can result in legionellosis, making water management programs (WMPs) important for patient safety. However, knowledge is limited on Legionella prevalence in healthcare buildings. A dataset of quarterly water testing in Veterans Health Administration (VHA) healthcare buildings was used to examine national environmental Legionella prevalence from 2015 to 2018. Bayesian hierarchical logistic regression modeling assessed factors influencing Legionella positivity. The master dataset included 201,146 water samples from 814 buildings at 168 VHA campuses. Overall Legionella positivity over the 4 years decreased from 7.2 to 5.1%, with the odds of a Legionella-positive sample being 0.94 (0.90-0.97) times the odds of a positive sample in the previous quarter for the 16 quarters of the 4 year period. Positivity varied considerably more at the medical center campus level compared to regional levels or to the building level where controls are typically applied. We found higher odds of Legionella detection in older buildings (OR 0.92 [0.86-0.98] for each more recent decade of construction), in taller buildings (OR 1.20 [1.13-1.27] for each additional floor), in hot water samples (O.R. 1.21 [1.16-1.27]), and in samples with lower residual biocide concentrations. This comprehensive healthcare building review showed reduced Legionella detection in the VHA healthcare system over time. Insights into factors associated with Legionella positivity provide information for healthcare systems implementing WMPs and for organizations setting standards and regulations.
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Affiliation(s)
- Shantini D Gamage
- National Infectious Diseases Service, Specialty Care Program Office, Veterans Health Administration, Department of Veterans Affairs (VA), Washington, D.C. 20571, United States
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States
| | - Chetan Jinadatha
- Department of Medicine, Central Texas Veterans Health Care System, Temple, Texas 76504, United States
- College of Medicine, Texas A&M University, Bryan, Texas 77807, United States
| | - John D Coppin
- Department of Research, Central Texas Veterans Health Care System, Temple, Texas 76504, United States
| | - Stephen M Kralovic
- National Infectious Diseases Service, Specialty Care Program Office, Veterans Health Administration, Department of Veterans Affairs (VA), Washington, D.C. 20571, United States
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States
- Cincinnati VA Medical Center, Cincinnati, Ohio 45220, United States
| | - Alan Bender
- Booz Allen Hamilton, McLean, Virginia 22102, United States
| | - Meredith Ambrose
- National Infectious Diseases Service, Specialty Care Program Office, Veterans Health Administration, Department of Veterans Affairs (VA), Washington, D.C. 20571, United States
| | - Brooke K Decker
- Division of Infectious Diseases, VA Pittsburgh Healthcare System, Pittsburgh, Pennsylvania 15240, United States
| | - Aaron S DeVries
- Minneapolis VA Healthcare System, Minneapolis, Minnesota 55417, United States
| | - Michihiko Goto
- Iowa City VA Health Care System, Iowa City, Iowa 52246, United States
- University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, United States
| | - Oleh Kowalskyj
- Office of Healthcare Engineering, Healthcare Environment and Facilities Program, Veterans Health Administration, VA, Washington, D.C. 20571, United States
| | - Angela L Maistros
- VA Capitol Health Care Network, Veterans Integrated Service Network (VISN) 5, Linthicum, Maryland 21090, United States
| | - Vincent Rizzo
- Office of Healthcare Engineering, Healthcare Environment and Facilities Program, Veterans Health Administration, VA, Washington, D.C. 20571, United States
| | - Loretta A Simbartl
- National Infectious Diseases Service, Specialty Care Program Office, Veterans Health Administration, Department of Veterans Affairs (VA), Washington, D.C. 20571, United States
| | - Richard J Watson
- Occupational Health and Safety Program Office, Veterans Health Administration, VA, Washington, D.C. 20571, United States
| | - Gary A Roselle
- National Infectious Diseases Service, Specialty Care Program Office, Veterans Health Administration, Department of Veterans Affairs (VA), Washington, D.C. 20571, United States
- Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267, United States
- Cincinnati VA Medical Center, Cincinnati, Ohio 45220, United States
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Walker JT, McDermott PJ. Confirming the Presence of Legionella pneumophila in Your Water System: A Review of Current Legionella Testing Methods. J AOAC Int 2021; 104:1135-1147. [PMID: 33484265 PMCID: PMC8378878 DOI: 10.1093/jaoacint/qsab003] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/18/2020] [Accepted: 12/18/2020] [Indexed: 12/24/2022]
Abstract
Legionnaires' disease has been recognized since 1976 and Legionella pneumophila still accounts for more than 95% of cases. Approaches in countries, including France, suggest that focusing risk reduction specifically on L. pneumophila is an effective strategy, as detecting L. pneumophila has advantages over targeting multiple species of Legionella. In terms of assays, the historically accepted plate culture method takes 10 days for confirmed Legionella spp. results, has variabilities which affect trending and comparisons, requires highly trained personnel to identify colonies on a plate in specialist laboratories, and does not recover viable-but-non-culturable bacteria. PCR is sensitive, specific, provides results in less than 24 h, and determines the presence/absence of Legionella spp. and/or L. pneumophila DNA. Whilst specialist personnel and laboratories are generally required, there are now on-site PCR options, but there is no agreement on comparing genome units to colony forming units and action limits. Immunomagnetic separation assays are culture-independent, detect multiple Legionella species, and results are available in 24 h, with automated processing options. Field-use lateral flow devices provide presence/absence determination of L. pneumophila serogroup 1 where sufficient cells are present, but testing potable waters is problematic. Liquid culture most probable number (MPN) assays provide confirmed L. pneumophila results in 7 days that are equivalent to or exceed plate culture, are robust and reproducible, and can be performed in a variety of laboratory settings. MPN isolates can be obtained for epidemiological investigations. This accessible, non-technical review will be of particular interest to building owners, operators, risk managers, and water safety groups and will enable them to make informed decisions to reduce the risk of L. pneumophila.
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Keserue HA, Cornillie N, Ehlert AK, Mills DC, Morger D, Piffaretti A, Schaffhauser DF, Schwyzer II. Validation of the Legionella pneumophila SG1 DETECT Kit for Quantification of Legionella pneumophila Serogroup 1 Bacteria in Potable Waters, Process Waters, and Surface Waters: AOAC Performance Tested MethodSM 052002. J AOAC Int 2021; 104:776-789. [PMID: 33609035 DOI: 10.1093/jaoacint/qsaa126] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 08/26/2020] [Indexed: 11/12/2022]
Abstract
The L.p.SG1 DETECT Kit is a rapid, quantitative method for the detection and enumeration of Legionella pneumophila serogroup 1 (L.p. SG1) bacteria from different water matrixes. The method is based on a combination of immunomagnetic separation (IMS) and flow cytometric (FCM) quantification. To this end, the method employs magnetic particles conjugated to anti-L.p. SG1 antibodies for the IMS of the target bacteria from environmental matrices and fluorescently labeled anti-L.p. SG1 antibodies for subsequent quantification by FCM. The IMS can be performed either manually with a magnetic rack (rqmicro.MIMS) or automated with the rqmicro.STREAM sample preparation instrument. Compared to the reference method ISO 11731:2017, which is based on culturing and enumeration of colony forming units (CFU) on agar plates, and can take up to 10 days until results are available, analysis with the L.p. SG1 DETECT Kit is culture-independent and delivers results within 2 h. This Performance Tested Method validation study demonstrates a robust method with recoveries exceeding 69%, inclusivity of 100%, exclusivity of 97.2%, and a shelf life of at least 6 months at 4°C or 40 days at 25°C. The Limit of Detection (LOD) was determined at 21 CFU/L and the Limit of Quantification (LOQ) at 80 CFU/L for potable water using the rqmicro.STREAM. The matrix study across three different types of water matrixes (potable, surface, and industrial process water), demonstrates superior repeatability and reproducibility, as well as equivalent or even superior detection of L.p. SG1 bacteria compared to the standard ISO 11731 method.
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Affiliation(s)
| | | | | | | | - Damien Morger
- rqmicro AG, Brandstrasse 24, 8952 Schlieren, Switzerland
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Toplitsch D, Platzer S, Zehner R, Maitz S, Mascher F, Kittinger C. Comparison of Updated Methods for Legionella Detection in Environmental Water Samples. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2021; 18:ijerph18105436. [PMID: 34069615 PMCID: PMC8161308 DOI: 10.3390/ijerph18105436] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 12/04/2022]
Abstract
The difficulty of cultivation of Legionella spp. from water samples remains a strenuous task even for experienced laboratories. The long incubation periods for Legionellae make isolation difficult. In addition, the water samples themselves are often contaminated with accompanying microbial flora, and therefore require complex cultivation methods from diagnostic laboratories. In addition to the recent update of the standard culture method ISO 11731:2017, new strategies such as quantitative PCR (qPCR) are often discussed as alternatives or additions to conventional Legionella culture approaches. In this study, we compared ISO 11731:2017 with qPCR assays targeting Legionella spp., Legionella pneumophila, and Legionella pneumophila serogroup 1. In samples with a high burden of accompanying microbial flora, qPCR shows an excellent negative predictive value for Legionella pneumophila, thus making qPCR an excellent tool for pre-selection of negative samples prior to work-intensive culture methods. This and its low limit of detection make qPCR a diagnostic asset in Legionellosis outbreak investigations, where quick-risk assessments are essential, and are a useful method for monitoring risk sites.
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Performance of Legiolert Test vs. ISO 11731 to Confirm Legionella pneumophila Contamination in Potable Water Samples. Pathogens 2020; 9:pathogens9090690. [PMID: 32842454 PMCID: PMC7560050 DOI: 10.3390/pathogens9090690] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 08/21/2020] [Accepted: 08/21/2020] [Indexed: 12/15/2022] Open
Abstract
Detection and enumeration of Legionella in water samples is of great importance for risk assessment analysis. The plate culture method is the gold standard, but has received several well-known criticisms, which have induced researchers to develop alternative methods. The purpose of this study was to compare Legionella counts obtained by the analysis of potable water samples through the plate culture method and through the IDEXX liquid culture Legiolert method. Legionella plate culture, according to ISO 11731:1998, was performed using 1 L of water. Legiolert was performed using both the 10 mL and 100 mL Legiolert protocols. Overall, 123 potable water samples were analyzed. Thirty-seven (30%) of them, positive for L. pneumophila, serogroups 1 or 2–14 by plate culture, were used for comparison with the Legiolert results. The Legiolert 10 mL test detected 34 positive samples (27.6%) and the Legiolert 100 mL test detected 37 positive samples, 27.6% and 30% respectively, out of the total samples analyzed. No significant difference was found between either the Legiolert 10 mL and Legiolert 100 mL vs. the plate culture (p = 0.9 and p = 0.3, respectively) or between the Legiolert 10 mL and Legiolert 100 mL tests (p = 0.83). This study confirms the reliability of the IDEXX Legiolert test for Legionella pneumophila detection and enumeration, as already shown in similar studies. Like the plate culture method, the Legiolert assay is also suitable for obtaining isolates for typing purposes, relevant for epidemiological investigations.
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Saad M, Chinerman D, Tabrizian M, Faucher SP. Identification of two aptamers binding to Legionella pneumophila with high affinity and specificity. Sci Rep 2020; 10:9145. [PMID: 32499557 PMCID: PMC7272621 DOI: 10.1038/s41598-020-65973-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Accepted: 05/13/2020] [Indexed: 12/21/2022] Open
Abstract
Legionella pneumophila (Lp) is a water borne bacterium causing Legionnaires’ Disease (LD) in humans. Rapid detection of Lp in water system is essential to reduce the risk of LD outbreaks. The methods currently available require expert skills and are time intensive, thus delaying intervention. In situ detection of Lp by biosensor would allow rapid implementation of control strategies. To this end, a biorecognition element is required. Aptamers are considered promising biorecognition molecules for biosensing. Aptamers are short oligonucleotide sequence folding into a specific structure and are able to bind to specific molecules. Currently, no aptamer and thus no aptamer-based technology exists for the detection of Lp. In this study, Systemic Evolution of Ligands through EXponential enrichment (SELEX) was used to identify aptamers binding specifically to Lp. Ten rounds of positive selection and two rounds of counter-selection against two Pseudomonas species were performed. Two aptamers binding strongly to Lp were identified with KD of 116 and 135 nM. Binding specificity of these two aptamers to Lp was confirmed by flow cytometry and fluorescence microscopy. Therefore, these two aptamers are promising biorecognition molecules for the detection of Lp in water systems.
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Affiliation(s)
- Mariam Saad
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada.,Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, J2S 2M2, Canada
| | - Deanna Chinerman
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada
| | - Maryam Tabrizian
- Department of Biomedical Engineering, Faculty of Medicine, McGill University, Montreal, Quebec, H3A 2B4, Canada.,Faculty of Dentistry, McGill University, Montreal, Quebec, H3A 2B4, Canada
| | - Sebastien P Faucher
- Department of Natural Resource Sciences, Faculty of Agricultural and Environmental Sciences, McGill University, Ste-Anne-de-Bellevue, Quebec, H9X 3V9, Canada. .,Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Université de Montréal, Faculté de Médecine Vétérinaire, Saint-Hyacinthe, Québec, J2S 2M2, Canada.
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Rhoads WJ, Bradley TN, Mantha A, Buttling L, Keane T, Pruden A, Edwards MA. Residential water heater cleaning and occurrence of Legionella in Flint, MI. WATER RESEARCH 2020; 171:115439. [PMID: 31940510 DOI: 10.1016/j.watres.2019.115439] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Revised: 12/13/2019] [Accepted: 12/22/2019] [Indexed: 06/10/2023]
Abstract
After the Federal emergency in Flint, MI was declared in early 2016 in response to elevated lead-in-water and incidence of Legionnaires' disease, concerns arose that contaminants in residential water heaters could continue to contribute to poor quality tap water. Here, a comprehensive field survey of residential water heaters (n = 30) and associated water quality was conducted and the subsequent effects of an aggressive manual water heater clean-out was determined, including draining the tank and removing sediments via brushing and flushing. Before cleaning, inorganics accumulated in the tank sediments did not serve as a source of metals measured at hot water outlets. After cleaning, hardness- (calcium, magnesium, silica) and corrosion-associated inorganics (lead, iron, copper, aluminum, zinc) decreased by 64% in samples from sediment cleanout drain valves. Culturable L. pneumophila was only detected in 1 home (3.3%) prior to cleaning and 2 homes (6.7%) after cleaning, thus quantitative polymerase chain reaction was used to quantify potential effects on unculturable strains despite the limitation of differentiating live and dead cells. After the cleaning protocol, Legionella spp. and L. pneumophila gene numbers decreased or remained non-detectable in 83% and 98% of samples, respectively. Homes with less than 0.4 mg/L influent free chlorine tended to have quantifiable Legionella spp. gene numbers in water entering the home and had elevated L. pneumophila and Legionella spp. gene numbers throughout the home plumbing. Also, Legionella spp. and L. pneumophila gene numbers were highest for water heaters set at or below ∼42 °C and significantly decreased >51 °C, consistent with Legionella's preferred temperature range. Examination of the only home that had culturable L. pneumophila both before and after the cleaning protocol revealed that the organism was culturable from several sample locations throughout the home, including in water representative of the water main. Notably, the home was located in close proximity to McLaren Hospital, where an outbreak of Legionnaires disease was reported, and the water heater had a setpoint within the Legionella growth range of 44.2 °C. Considering that other factors were more strongly associated with Legionella occurrence and water heater sediment was not detectably mobilizing to tap water, it was concluded that water heater cleaning had some benefits, but was not an overarching factor contributing to possible human health risks.
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Affiliation(s)
- William J Rhoads
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA.
| | - Taylor N Bradley
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Anurag Mantha
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Lauren Buttling
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Tim Keane
- Legionella Risk Management, Chalfont, PA, USA
| | - Amy Pruden
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA
| | - Marc A Edwards
- Virginia Tech, Civil and Environmental Engineering, Blacksburg, VA, USA.
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11
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Ahmed S, Liwak-Muir U, Walker D, Zoldowski A, Mears A, Golovan S, Mohr S, Lem P, Harder C. Validation and in-field testing of a new on-site qPCR system for quantification of Legionella pneumophila according to ISO/TS 12869:2012 in HVAC cooling towers. JOURNAL OF WATER AND HEALTH 2019; 17:237-253. [PMID: 30942774 DOI: 10.2166/wh.2019.252] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Legionella pneumophila, found in engineered water systems such as HVAC cooling towers, poses a significant public health risk. Culture, though routinely used to quantify L. pneumophila, has several disadvantages including long turnaround time, low sensitivity, and inter-laboratory variability. In this study, we validated the performance of an on-site quantitative polymerase chain reaction (qPCR) detection system for L. pneumophila in accordance with International Standards Organization Technical Specification 12869:2012. We evaluated specificity, limit of detection and quantification, and calibration curve linearity. Additionally, we evaluated whole system recovery and robustness using samples taken from taps and evaporative cooling towers. We then compared the system's performance against laboratory culture and laboratory qPCR across 53 cooling towers in a 12-week in-field study. We found that concordance between on-site qPCR and culture was both laboratory- and site/sample-dependent. Comparison of laboratory qPCR with on-site qPCR revealed that laboratory results were highly variable and showed little concordance. Some discordance may be explained by time delay between sample collection and testing ('shipping effect') which may lead to inaccurate reporting. Overall, our study highlights the value of on-site qPCR detection of L. pneumophila, demonstrates that laboratories are prone to misreporting results due to shipping effects, and reveals significant discordance between laboratory qPCR and culture.
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Affiliation(s)
- Shaimaa Ahmed
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Urszula Liwak-Muir
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Danielle Walker
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Agnes Zoldowski
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Alan Mears
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Sergey Golovan
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Steve Mohr
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Paul Lem
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
| | - Chris Harder
- Spartan Bioscience Inc., 2934 Baseline Road, Suite 500, Ottawa, ON K2H 1B2, Canada E-mail:
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Environmental Validation of Legionella Control in a VHA Facility Water System. Infect Control Hosp Epidemiol 2018; 39:259-266. [PMID: 29397802 DOI: 10.1017/ice.2017.318] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVES We conducted this study to determine what sample volume, concentration, and limit of detection (LOD) are adequate for environmental validation of Legionella control. We also sought to determine whether time required to obtain culture results can be reduced compared to spread-plate culture method. We also assessed whether polymerase chain reaction (PCR) and in-field total heterotrophic aerobic bacteria (THAB) counts are reliable indicators of Legionella in water samples from buildings. DESIGN Comparative Legionella screening and diagnostics study for environmental validation of a healthcare building water system. SETTING Veterans Health Administration (VHA) facility water system in central Texas. METHODS We analyzed 50 water samples (26 hot, 24 cold) from 40 sinks and 10 showers using spread-plate cultures (International Standards Organization [ISO] 11731) on samples shipped overnight to the analytical lab. In-field, on-site cultures were obtained using the PVT (Phigenics Validation Test) culture dipslide-format sampler. A PCR assay for genus-level Legionella was performed on every sample. RESULTS No practical differences regardless of sample volume filtered were observed. Larger sample volumes yielded more detections of Legionella. No statistically significant differences at the 1 colony-forming unit (CFU)/mL or 10 CFU/mL LOD were observed. Approximately 75% less time was required when cultures were started in the field. The PCR results provided an early warning, which was confirmed by spread-plate cultures. The THAB results did not correlate with Legionella status. CONCLUSIONS For environmental validation at this facility, we confirmed that (1) 100 mL sample volumes were adequate, (2) 10× concentrations were adequate, (3) 10 CFU/mL LOD was adequate, (4) in-field cultures reliably reduced time to get results by 75%, (5) PCR provided a reliable early warning, and (6) THAB was not predictive of Legionella results. Infect Control Hosp Epidemiol 2018;39:259-266.
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Llewellyn AC, Lucas CE, Roberts SE, Brown EW, Nayak BS, Raphael BH, Winchell JM. Distribution of Legionella and bacterial community composition among regionally diverse US cooling towers. PLoS One 2017; 12:e0189937. [PMID: 29261791 PMCID: PMC5738086 DOI: 10.1371/journal.pone.0189937] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 12/05/2017] [Indexed: 11/19/2022] Open
Abstract
Cooling towers (CTs) are a leading source of outbreaks of Legionnaires' disease (LD), a severe form of pneumonia caused by inhalation of aerosols containing Legionella bacteria. Accordingly, proper maintenance of CTs is vital for the prevention of LD. The aim of this study was to determine the distribution of Legionella in a subset of regionally diverse US CTs and characterize the associated microbial communities. Between July and September of 2016, we obtained aliquots from water samples collected for routine Legionella testing from 196 CTs located in eight of the nine continental US climate regions. After screening for Legionella by PCR, positive samples were cultured and the resulting Legionella isolates were further characterized. Overall, 84% (164) were PCR-positive, including samples from every region studied. Of the PCR-positive samples, Legionella spp were isolated from 47% (78), L. pneumophila was isolated from 32% (53), and L. pneumophila serogroup 1 (Lp1) was isolated from 24% (40). Overall, 144 unique Legionella isolates were identified; 53% (76) of these were Legionella pneumophila. Of the 76 L. pneumophila isolates, 51% (39) were Lp1. Legionella were isolated from CTs in seven of the eight US regions examined. 16S rRNA amplicon sequencing was used to compare the bacterial communities of CT waters with and without detectable Legionella as well as the microbiomes of waters from different climate regions. Interestingly, the microbial communities were homogenous across climate regions. When a subset of seven CTs sampled in April and July were compared, there was no association with changes in corresponding CT microbiomes over time in the samples that became culture-positive for Legionella. Legionella species and Lp1 were detected frequently among the samples examined in this first large-scale study of Legionella in US CTs. Our findings highlight that, under the right conditions, there is the potential for CT-related LD outbreaks to occur throughout the US.
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Affiliation(s)
- Anna C. Llewellyn
- Laboratory Leadership Service, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
- Pneumonia Response and Surveillance Laboratory, Respiratory Disease Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Claressa E. Lucas
- Pneumonia Response and Surveillance Laboratory, Respiratory Disease Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Sarah E. Roberts
- Pneumonia Response and Surveillance Laboratory, Respiratory Disease Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Ellen W. Brown
- Pneumonia Response and Surveillance Laboratory, Respiratory Disease Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Bina S. Nayak
- Water Quality Division, Pinellas County Utilities, Largo, FL, United States of America
| | - Brian H. Raphael
- Pneumonia Response and Surveillance Laboratory, Respiratory Disease Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
| | - Jonas M. Winchell
- Pneumonia Response and Surveillance Laboratory, Respiratory Disease Branch, Centers for Disease Control and Prevention, Atlanta, GA, United States of America
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Veenendaal HR, Brouwer-Hanzens AJ, van der Kooij D. Incubation of premise plumbing water samples on Buffered Charcoal Yeast Extract agar at elevated temperature and pH selects for Legionella pneumophila. WATER RESEARCH 2017; 123:439-447. [PMID: 28689128 DOI: 10.1016/j.watres.2017.06.077] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Revised: 05/30/2017] [Accepted: 06/26/2017] [Indexed: 06/07/2023]
Abstract
Worldwide, over 90% of the notified cases of Legionnaires' disease are caused by Legionella pneumophila. However, the standard culture medium for the detection of Legionella in environmental water samples, Buffered Charcoal Yeast Extract (BCYE) agar of pH 6.9 ± 0.4 with or without antimicrobial agents incubated at 36 ± 1 °C, supports the growth of a large diversity of Legionella species. BCYE agar of elevated pH or/and incubation at elevated temperature gave strongly reduced recoveries of most of 26 L. non-pneumophila spp. tested, but not of L. pneumophila. BCYE agar of pH 7.3 ± 0.1, incubated at 40 ± 0.5 °C (BCYE pH 7.3/40 °C) was tested for selective enumeration of L. pneumophila. Of the L. non-pneumophila spp. tested, only L. adelaidensis and L. londiniensis multiplied under these conditions. The colony counts on BCYE pH 7.3/40 °C of a L. pneumophila serogroup 1 strain cultured in tap water did not differ significantly from those on BCYE pH 6.9/36 °C when directly plated and after membrane filtration and showed repeatability's of 13-14%. By using membrane filtration L. pneumophila was detected in 58 (54%) of 107 Legionella-positive water samples from premise plumbing systems under one or both of these culture conditions. The L. pneumophila colony counts (log-transformed) on BCYE pH 7.3/40 °C were strongly related (r2 = 0.87) to those on BCYE pH 6.9/36 °C, but differed significantly (p < 0.05) by a mean of - 0.12 ± 0.30 logs. L. non-pneumophila spp. were detected only on BCYE pH 6.9/36 °C in 49 (46%) of the samples. Hence, BCYE pH 7.3/40 °C can facilitate the enumeration of L. pneumophila and their isolation from premise plumbing systems with culturable L. non-pneumophila spp., some of which, e.g. L. anisa, can be present in high numbers.
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Affiliation(s)
- Harm R Veenendaal
- KWR Watercycle Research Institute, PO Box 1072, 3430 BB, Nieuwegein, The Netherlands
| | | | - Dick van der Kooij
- KWR Watercycle Research Institute, PO Box 1072, 3430 BB, Nieuwegein, The Netherlands.
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15
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Kuhn P, Thiem S, Steinert M, Purvis D, Lugmayr V, Treutlein U, Plobner L, Leiser RM, Hust M, Dübel S. Human Anti-Lipopolysaccharid (LPS) antibodies against Legionella with high species specificity. Hum Antibodies 2017; 26:29-38. [PMID: 28582852 DOI: 10.3233/hab-170318] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Legionella are Gram-negative bacteria that are ubiquitously present in natural and man-made water reservoirs. When humans inhale aerosolized water contaminated with Legionella, alveolar macrophages can be infected, which may lead to a life-threatening pneumonia called Legionnaires' disease. Due to the universal distribution of Legionella in water and their potential threat to human health, the Legionella concentration in water for human use must be strictly monitored, which is difficult since the standard detection still relies on lengthy cultivation and analysis of bacterial morphology. In this study, an antibody against L. pneumophila has been generated from the naïve human HAL antibody libraries by phage-display for the first time. The panning was performed on whole bacterial cells in order to select antibodies that bind specifically to the cell surface of untreated Legionella. The bacterial cell wall component lipopolysaccharide (LPS) was identified as the target structure. Specific binding to the important pathogenic L. pneumophila strains Corby, Philadelphia-1 and Knoxville was observed, while no binding was detected to seven members of the families Enterobacteriaceae, Pseudomonadaceae or Clostridiaceae. Production of this antibody in the recombinant scFv-Fc format using either a murine or a human Fc part allowed the set-up of a sandwich-ELISA for detection of Legionella cells. The scFv-Fc construct proved to be very stable, even when stored for several weeks at elevated temperatures. A sensitivity limit of 4,000 cells was achieved. The scFv-Fc antibody pair was integrated on a biosensor, demonstrating the specific and fast detection of L. pneumophila on a portable device. With this system, 10,000 Legionella cells were detected within 35 min. Combined with a water filtration/concentration system, this antibody may be developed into a promising reagent for rapid on-site Legionella monitoring.
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Affiliation(s)
- Philipp Kuhn
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany
- YUMAB GmbH, Rebenring, Braunschweig, Germany
| | - Stefanie Thiem
- Institute for Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
- Department of Animal Breeding and Genetics, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Michael Steinert
- Institute for Microbiology, Technische Universität Braunschweig, Braunschweig, Germany
- Helmholtz Center for Infection Research, Braunschweig, Germany
| | | | | | | | | | | | - Michael Hust
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Stefan Dübel
- Biotechnology and Bioinformatics, Institute for Biochemistry, Technische Universität Braunschweig, Braunschweig, Germany
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Gamage SD, Ambrose M, Kralovic SM, Roselle GA. Water Safety and Legionella in Health Care: Priorities, Policy, and Practice. Infect Dis Clin North Am 2017; 30:689-712. [PMID: 27515143 DOI: 10.1016/j.idc.2016.04.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Health care facility water distribution systems have been implicated in the transmission of pathogens such as Legionella and nontuberculous mycobacteria to building occupants. These pathogens are natural inhabitants of water at low numbers and can amplify in premise plumbing water, especially if conditions are conducive to their growth. Because patients and residents in health care facilities are often at heightened risk for opportunistic infections, a multidisciplinary proactive approach to water safety is important to balance the various water priorities in health care and prevent water-associated infections in building occupants.
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Affiliation(s)
- Shantini D Gamage
- National Infectious Diseases Service, Specialty Care Services, Patient Care Services, Veterans Health Administration, Department of Veterans Affairs (VA), 810 Vermont Avenue, NW, Washington, DC 20420, USA; Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, OH 45267, USA.
| | - Meredith Ambrose
- National Infectious Diseases Service, Specialty Care Services, Patient Care Services, Veterans Health Administration, Department of Veterans Affairs (VA), 810 Vermont Avenue, NW, Washington, DC 20420, USA
| | - Stephen M Kralovic
- National Infectious Diseases Service, Specialty Care Services, Patient Care Services, Veterans Health Administration, Department of Veterans Affairs (VA), 810 Vermont Avenue, NW, Washington, DC 20420, USA; Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, OH 45267, USA; Medical Service, Cincinnati VA Medical Center, 3200 Vine Street, Cincinnati, OH 45220, USA
| | - Gary A Roselle
- National Infectious Diseases Service, Specialty Care Services, Patient Care Services, Veterans Health Administration, Department of Veterans Affairs (VA), 810 Vermont Avenue, NW, Washington, DC 20420, USA; Division of Infectious Diseases, Department of Internal Medicine, University of Cincinnati College of Medicine, 3230 Eden Avenue, Cincinnati, OH 45267, USA; Medical Service, Cincinnati VA Medical Center, 3200 Vine Street, Cincinnati, OH 45220, USA
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17
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Wang H, Bédard E, Prévost M, Camper AK, Hill VR, Pruden A. Methodological approaches for monitoring opportunistic pathogens in premise plumbing: A review. WATER RESEARCH 2017; 117:68-86. [PMID: 28390237 PMCID: PMC5693313 DOI: 10.1016/j.watres.2017.03.046] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 03/19/2017] [Accepted: 03/22/2017] [Indexed: 05/06/2023]
Abstract
Opportunistic premise (i.e., building) plumbing pathogens (OPPPs, e.g., Legionella pneumophila, Mycobacterium avium complex, Pseudomonas aeruginosa, Acanthamoeba, and Naegleria fowleri) are a significant and growing source of disease. Because OPPPs establish and grow as part of the native drinking water microbiota, they do not correspond to fecal indicators, presenting a major challenge to standard drinking water monitoring practices. Further, different OPPPs present distinct requirements for sampling, preservation, and analysis, creating an impediment to their parallel detection. The aim of this critical review is to evaluate the state of the science of monitoring OPPPs and identify a path forward for their parallel detection and quantification in a manner commensurate with the need for reliable data that is informative to risk assessment and mitigation. Water and biofilm sampling procedures, as well as factors influencing sample representativeness and detection sensitivity, are critically evaluated with respect to the five representative bacterial and amoebal OPPPs noted above. Available culturing and molecular approaches are discussed in terms of their advantages, limitations, and applicability. Knowledge gaps and research needs towards standardized approaches are identified.
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Affiliation(s)
- Hong Wang
- State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Emilie Bédard
- Department of Civil Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Michèle Prévost
- Department of Civil Engineering, Polytechnique Montreal, Montreal, QC, Canada
| | - Anne K Camper
- Center for Biofilm Engineering and Department of Civil Engineering, Montana State University, Bozeman, MT 59717, USA
| | - Vincent R Hill
- Waterborne Disease Prevention Branch, Centers for Disease Control and Prevention, 1600 Clifton Road NE, Atlanta, GA 30329, USA
| | - Amy Pruden
- Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
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18
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Whiley H. Legionella Risk Management and Control in Potable Water Systems: Argument for the Abolishment of Routine Testing. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2016; 14:E12. [PMID: 28029126 PMCID: PMC5295263 DOI: 10.3390/ijerph14010012] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 12/20/2016] [Accepted: 12/22/2016] [Indexed: 01/05/2023]
Abstract
Legionella is an opportunistic pathogen of public health significance. One of the main sources of Legionella is potable water systems. As a consequence of aging populations there is an increasing demographic considered at high risk for Legionellosis and, as such, a review of the guidelines is required. Worldwide, Legionella has been detected from many potable water sources, suggesting it is ubiquitous in this environment. Previous studies have identified the limitations of the current standard method for Legionella detection and the high possibility of it returning both false negative and false positive results. There is also huge variability in Legionella test results for the same water sample when conducted at different laboratories. However, many guidelines still recommend the testing of water systems. This commentary argues for the removal of routine Legionella monitoring from all water distribution guidelines. This procedure is financially consuming and false negatives may result in managers being over-confident with a system or a control mechanism. Instead, the presence of the pathogen should be assumed and focus spent on managing appropriate control measures and protecting high-risk population groups.
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Affiliation(s)
- Harriet Whiley
- Health and the Environment, School of the Environment, Flinders University, GPO Box 2100, Adelaide 5001, Australia.
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19
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Culture positivity and bacterial burden thresholds for Legionella in hospital water: Proceed with caution. Am J Infect Control 2016; 44:730. [PMID: 26851195 DOI: 10.1016/j.ajic.2015.11.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 11/05/2015] [Indexed: 11/23/2022]
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20
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Parr A, Whitney EA, Berkelman RL. Legionellosis on the Rise: A Review of Guidelines for Prevention in the United States. JOURNAL OF PUBLIC HEALTH MANAGEMENT AND PRACTICE 2015; 21:E17-26. [PMID: 25203696 PMCID: PMC4519350 DOI: 10.1097/phh.0000000000000123] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
CONTEXT Reported cases of legionellosis more than tripled between 2001 and 2012 in the United States. The disease results primarily from exposure to aerosolized water contaminated with Legionella. OBJECTIVE To identify and describe policies and guidelines for the primary prevention of legionellosis in the US. DESIGN An Internet search for Legionella prevention guidelines in the United States at the federal and state levels was conducted from March to June 2012. Local government agency guidelines and guidelines from professional organizations that were identified in the initial search were also included. SETTING Federal, state, and local governing bodies and professional organizations. RESULTS Guidelines and regulations for the primary prevention of legionellosis (ie, Legionnaires' disease and Pontiac fever) have been developed by various public health and other government agencies at the federal, state, and local levels as well as by professional organizations. These guidelines are similar in recommending maintenance of building water systems; federal and other guidelines differ in the population/institutions targeted, the extent of technical detail, and support of monitoring water systems for levels of Legionella contamination. CONCLUSIONS Legionellosis deserves a higher public health priority for research and policy development. Guidance across public health agencies for the primary prevention of legionellosis requires strengthening as this disease escalates in importance as a cause of severe morbidity and mortality. We recommend a formal and comprehensive review of national public health guidelines for prevention of legionellosis.
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Affiliation(s)
- Alyssa Parr
- Center for Public Health Preparedness and Research, Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, Georgia
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21
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McCoy WF, Rosenblatt AA. HACCP-Based Programs for Preventing Disease and Injury from Premise Plumbing: A Building Consensus. Pathogens 2015; 4:513-28. [PMID: 26184325 PMCID: PMC4584270 DOI: 10.3390/pathogens4030513] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 07/04/2015] [Accepted: 07/06/2015] [Indexed: 12/22/2022] Open
Abstract
Thousands of preventable injuries and deaths are annually caused by microbial, chemical and physical hazards from building water systems. Water is processed in buildings before use; this can degrade the quality of the water. Processing steps undertaken on-site in buildings often include conditioning, filtering, storing, heating, cooling, pressure regulation and distribution through fixtures that restrict flow and temperature. Therefore, prevention of disease and injury requires process management. A process management framework for buildings is the hazard analysis and critical control point (HACCP) adaptation of failure mode effects analysis (FMEA). It has been proven effective for building water system management. Validation is proof that hazards have been controlled under operating conditions and may include many kinds of evidence including cultures of building water samples to detect and enumerate potentially pathogenic microorganisms. However, results from culture tests are often inappropriately used because the accuracy and precision are not sufficient to support specifications for control limit or action triggers. A reliable negative screen is based on genus-level Polymerase Chain Reaction (PCR) for Legionella in building water systems; however, building water samples with positive results from this test require further analysis by culture methods.
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Affiliation(s)
- William F McCoy
- Phigenics, LLC, 1701 Quincy Ave., Suite 32, Naperville, IL 60540, USA.
| | - Aaron A Rosenblatt
- Gordon & Rosenblatt, LLC, 45 Rockefeller Plaza, 20th Floor, New York, NY 10111, USA.
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22
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Omiccioli E, Schiavano GF, Ceppetelli V, Amagliani G, Magnani M, Brandi G. Validation according to ISO/TS 12869:2012 of a molecular method for the isolation and quantification of Legionella spp. in water. Mol Cell Probes 2015; 29:86-91. [DOI: 10.1016/j.mcp.2014.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
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23
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Demirjian A, Lucas CE, Garrison LE, Kozak-Muiznieks NA, States S, Brown EW, Wortham JM, Beaudoin A, Casey ML, Marriott C, Ludwig AM, Sonel AF, Muder RR, Hicks LA. The Importance of Clinical Surveillance in Detecting Legionnaires' Disease Outbreaks: A Large Outbreak in a Hospital With a Legionella Disinfection System—Pennsylvania, 2011–2012. Clin Infect Dis 2015; 60:1596-602. [DOI: 10.1093/cid/civ153] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 02/15/2015] [Indexed: 11/13/2022] Open
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Mercante JW, Winchell JM. Current and emerging Legionella diagnostics for laboratory and outbreak investigations. Clin Microbiol Rev 2015; 28:95-133. [PMID: 25567224 PMCID: PMC4284297 DOI: 10.1128/cmr.00029-14] [Citation(s) in RCA: 214] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Legionnaires' disease (LD) is an often severe and potentially fatal form of bacterial pneumonia caused by an extensive list of Legionella species. These ubiquitous freshwater and soil inhabitants cause human respiratory disease when amplified in man-made water or cooling systems and their aerosols expose a susceptible population. Treatment of sporadic cases and rapid control of LD outbreaks benefit from swift diagnosis in concert with discriminatory bacterial typing for immediate epidemiological responses. Traditional culture and serology were instrumental in describing disease incidence early in its history; currently, diagnosis of LD relies almost solely on the urinary antigen test, which captures only the dominant species and serogroup, Legionella pneumophila serogroup 1 (Lp1). This has created a diagnostic "blind spot" for LD caused by non-Lp1 strains. This review focuses on historic, current, and emerging technologies that hold promise for increasing LD diagnostic efficiency and detection rates as part of a coherent testing regimen. The importance of cooperation between epidemiologists and laboratorians for a rapid outbreak response is also illustrated in field investigations conducted by the CDC with state and local authorities. Finally, challenges facing health care professionals, building managers, and the public health community in combating LD are highlighted, and potential solutions are discussed.
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Affiliation(s)
- Jeffrey W Mercante
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - Jonas M Winchell
- Pneumonia Response and Surveillance Laboratory, Respiratory Diseases Branch, U.S. Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Flanders WD, Kirkland KH, Shelton BG. Effects of holding time and measurement error on culturing Legionella in environmental water samples. WATER RESEARCH 2014; 62:293-301. [PMID: 24963890 DOI: 10.1016/j.watres.2014.05.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 05/09/2014] [Accepted: 05/19/2014] [Indexed: 06/03/2023]
Abstract
Outbreaks of Legionnaires' disease require environmental testing of water samples from potentially implicated building water systems to identify the source of exposure. A previous study reports a large impact on Legionella sample results due to shipping and delays in sample processing. Specifically, this same study, without accounting for measurement error, reports more than half of shipped samples tested had Legionella levels that arbitrarily changed up or down by one or more logs, and the authors attribute this result to shipping time. Accordingly, we conducted a study to determine the effects of sample holding/shipping time on Legionella sample results while taking into account measurement error, which has previously not been addressed. We analyzed 159 samples, each split into 16 aliquots, of which one-half (8) were processed promptly after collection. The remaining half (8) were processed the following day to assess impact of holding/shipping time. A total of 2544 samples were analyzed including replicates. After accounting for inherent measurement error, we found that the effect of holding time on observed Legionella counts was small and should have no practical impact on interpretation of results. Holding samples increased the root mean squared error by only about 3-8%. Notably, for only one of 159 samples, did the average of the 8 replicate counts change by 1 log. Thus, our findings do not support the hypothesis of frequent, significant (≥= 1 log10 unit) Legionella colony count changes due to holding.
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Affiliation(s)
- W Dana Flanders
- Department of Epidemiology, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
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26
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Krageschmidt DA, Kubly AF, Browning MS, Wright AJ, Lonneman JD, Detmer MJ, McCoy WF. A comprehensive water management program for multicampus healthcare facilities. Infect Control Hosp Epidemiol 2014; 35:556-63. [PMID: 24709725 DOI: 10.1086/675822] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Develop and implement an effective program for hazard analysis and control of waterborne pathogens at a multicampus hospital with clinics. DESIGN A longitudinal study. Several-year study including analysis of results from monitoring and tests of 26 building water systems. SETTING Outpatient and inpatient healthcare facilities network. METHODS The hazard analysis and critical control point (HACCP) process was used to develop a water management program (WMP) for the hospital campuses. The HACCP method systematically addressed 3 questions: (1) What are the potential waterborne hazards in the building water systems of these facilities? (2) How are the hazards being controlled? (3) How do we know that the hazards have been controlled? Microbiological and chemical tests of building water samples were used to validate the performance of the WMP; disease surveillance data further validated effective hazard control. RESULTS Hazard analysis showed that waterborne pathogens were generally in good control and that the water quality was good in all facilities. The hospital network has had several legionellosis cases that were identified as presumptive hospital acquired, but none was confirmed or substantiated by water testing in follow-up investigations. Building water system studies unrelated to these cases showed that pressure tanks and electronic automatic faucets required additional hazard control. CONCLUSIONS Application of the HACCP process for long-term building water systems management was practical and effective. The need for critical control point management of temperature, flow, and oxidant (chlorine) residual concentration was emphasized. The process resulted in discovery of water system components requiring additional hazard control.
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Abstract
Legionella is ubiquitous in freshwater systems worldwide and can also be found in soil. Legionellosis may be caused by inhalation of aerosolized water or soil particles containing Legionella. Isolation of Legionella from the environment is an essential step in outbreak investigation and may also be performed within the context of a hazard analysis and control risk management plan. Culture remains the gold standard for detection of Legionella in environmental samples. Specific properties of environmental sites that could be a source of Legionella contamination, collection of samples from such sites, and procedures for culture of these samples for Legionella are described in this chapter.
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Affiliation(s)
- Natalia A Kozak
- Centers for Disease Control and Prevention, Atlanta, GA, USA.
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Keserue H, Baumgartner A, Felleisen R, Egli T. Rapid detection of total and viable Legionella pneumophila in tap water by immunomagnetic separation, double fluorescent staining and flow cytometry. Microb Biotechnol 2012; 5:753-63. [PMID: 23062200 PMCID: PMC3815896 DOI: 10.1111/j.1751-7915.2012.00366.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
We developed a rapid detection method for Legionella pneumophila (Lp) by filtration, immunomagnetic separation, double fluorescent staining, and flow cytometry (IMS-FCM method). The method requires 120 min and can discriminate 'viable' and 'membrane-damaged' cells. The recovery is over 85% of spiked Lp SG 1 cells in 1 l of tap water and detection limits are around 50 and 15 cells per litre for total and viable Lp, respectively. The method was compared using water samples from house installations in a blind study with three environmental laboratories performing the ISO 11731 plating method. In 53% of the water samples from different taps and showers significantly higher concentrations of Lp were detected by flow cytometry. No correlation to the plate culture method was found. Since also 'viable but not culturable' (VNBC) cells are detected by our method, this result was expected. The IMS-FCM method is limited by the specificity of the used antibodies; in the presented case they target Lp serogroups 1-12. This and the fact that no Lp-containing amoebae are detected may explain why in 21% of all samples higher counts were observed using the plate culture method. Though the IMS-FCM method is not yet fit to completely displace the established plating method (ISO 11731) for routine Lp monitoring, it has major advantages to plating and can quickly provide important insights into the ecology of this pathogen in water distribution systems.
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Affiliation(s)
- Hans‐Anton Keserue
- Swiss Federal Institute for Aquatic Science and Technology (Eawag)Überlandstrasse 133, PO Box 611, CH‐8600, Dübendorf, Switzerland
- Federal Office of Public Health (FOPH)Schwarzenburgstrasse 165, CH‐3003, Bern, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH ZurichUniversitätsstrasse 16, 8092, Zurich, Switzerland
| | - Andreas Baumgartner
- Federal Office of Public Health (FOPH)Schwarzenburgstrasse 165, CH‐3003, Bern, Switzerland
| | - Richard Felleisen
- Federal Office of Public Health (FOPH)Schwarzenburgstrasse 165, CH‐3003, Bern, Switzerland
| | - Thomas Egli
- Swiss Federal Institute for Aquatic Science and Technology (Eawag)Überlandstrasse 133, PO Box 611, CH‐8600, Dübendorf, Switzerland
- Institute of Biogeochemistry and Pollutant Dynamics (IBP), ETH ZurichUniversitätsstrasse 16, 8092, Zurich, Switzerland
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McCoy WF, Downes EL, Leonidas LF, Cain MF, Sherman DL, Chen K, Devender S, Neville MJ. Inaccuracy in Legionella tests of building water systems due to sample holding time. WATER RESEARCH 2012; 46:3497-3506. [PMID: 22560149 DOI: 10.1016/j.watres.2012.03.062] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2011] [Revised: 03/27/2012] [Accepted: 03/28/2012] [Indexed: 05/31/2023]
Abstract
Most Legionella culture tests are performed on building water samples that have been shipped to analytical laboratories for analysis. Significant (≥ 1 log₁₀ unit) changes in results were observed in 52% of held samples (6 h or longer, ambient temperature) drawn from building water systems in a 42-sample initial survey. It was not practical to use the spread plate protocol for on-site "t = 0" cultures in a larger, more diverse survey of thousands of building water systems. Two thousand four hundred twenty-one (2421) building water samples were split for on-site analysis using a field culture protocol and then also cultured after overnight shipment to the lab for analysis with the standardized spread plate method. Legionella test results from building water system samples are usually interpreted as ≥ a numerical detection or action limit. Therefore, binary statistical analyses were calculated by setting t = 0 culture results to "true". Overall in this survey, 10.4% of water samples sent to the laboratory for analysis returned either false-positive or false-negative results. The overall positive predictive value of results was poor (36%). Most (83%) false-positive results were returned from utility water systems. Most (74%) false-negative results were returned from potable water systems. These inaccuracies have serious implications in regard to interpretation and use of Legionella test results. The overall negative predictive value of results was excellent (99%) and also it was good (92%) for results from a polymerase chain reaction (PCR) assay that can be therefore used as a negative screening method.
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Affiliation(s)
- William F McCoy
- Phigenics, LLC, 1701 Quincy Ave., Suite 32, Naperville, IL 60540, USA
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Molecular survey of the occurrence of Legionella spp., Mycobacterium spp., Pseudomonas aeruginosa, and amoeba hosts in two chloraminated drinking water distribution systems. Appl Environ Microbiol 2012; 78:6285-94. [PMID: 22752174 DOI: 10.1128/aem.01492-12] [Citation(s) in RCA: 170] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The spread of opportunistic pathogens via public water systems is of growing concern. The purpose of this study was to identify patterns of occurrence among three opportunistic pathogens (Legionella pneumophila, Mycobacterium avium, and Pseudomonas aeruginosa) relative to biotic and abiotic factors in two representative chloraminated drinking water distribution systems using culture-independent methods. Generally, a high occurrence of Legionella (≥69.0%) and mycobacteria (100%), lower occurrence of L. pneumophila (≤20%) and M. avium (≤33.3%), and rare detection of Pseudomonas aeruginosa (≤13.3%) were observed in both systems according to quantitative PCR. Also, Hartmanella vermiformis was more prevalent than Acanthamoeba, both of which are known hosts for opportunistic pathogen amplification, the latter itself containing pathogenic members. Three-minute flushing served to distinguish distribution system water from plumbing in buildings (i.e., premise plumbing water) and resulted in reduced numbers of copies of Legionella, mycobacteria, H. vermiformis, and 16S rRNA genes (P < 0.05) while yielding distinct terminal restriction fragment polymorphism (T-RFLP) profiles of 16S rRNA genes. Within certain subgroups of samples, some positive correlations, including correlations of numbers of mycobacteria and total bacteria (16S rRNA genes), H. vermiformis and total bacteria, mycobacteria and H. vermiformis, and Legionella and H. vermiformis, were noted, emphasizing potential microbial ecological relationships. Overall, the results provide insight into factors that may aid in controlling opportunistic pathogen proliferation in real-world water systems.
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Eight years of Legionnaires' disease transmission in travellers to a condominium complex in Las Vegas, Nevada. Epidemiol Infect 2012; 140:1993-2002. [PMID: 22214820 DOI: 10.1017/s0950268811002779] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Travel is a risk factor for Legionnaires' disease. In 2008, two cases were reported in condominium guests where we investigated a 2001 outbreak. We reinvestigated to identify additional cases and determine whether ongoing transmission resulted from persistent colonization of potable water. Exposures were assessed by matched case-control analyses (2001) and case-series interviews (2008). We sampled potable water and other water sources. Isolates were compared using sequence-based typing. From 2001 to 2008, 35 cases were identified. Confirmed cases reported after the cluster in 2001-2002 were initially considered sporadic, but retrospective case-finding identified five additional cases. Cases were more likely than controls to stay in tower 2 of the condominium [matched odds ratio (mOR) 6·1, 95% confidence interval (CI) 1·6-22·9]; transmission was associated with showering duration (mOR 23·0, 95% CI 1·4-384). We characterized a clinical isolate as sequence type 35 (ST35) and detected ST35 in samples of tower 2's potable water in 2001, 2002, and 2008. This prolonged outbreak illustrates the importance of striving for permanent Legionella eradication from potable water.
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