1
|
Fang Z, Zhou X, Liao H, Xu H. A meta-analysis of Legionella pneumophila contamination in hospital water systems. Am J Infect Control 2023; 51:1250-1262. [PMID: 37054892 DOI: 10.1016/j.ajic.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 03/31/2023] [Accepted: 04/01/2023] [Indexed: 04/15/2023]
Abstract
BACKGROUND Legionella pneumophila is a common cause of community-acquired pneumonia. We aimed to determine the pooled rates of L pneumophila contamination in the water environment of the hospital. METHODS We searched PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure, WangFang and Science Direct, The Cochrane Library, and Science Finder, for relevant studies published until December 2022. Stata 16.0 software was used to determine pooled contamination rates, publication bias, and subgroup analysis. RESULTS Forty-eight eligible articles with a total of 23,640 samples of water were evaluated, and the prevalence of L pneumophila was 41.6%. The results of the subgroup analysis showed that the pollution rate of L pneumophila in hot water (47.6%) was higher than that in other water bodies. The rates of L pneumophila contamination were higher in developed countries (45.2%), culture methods (42.3%), published between 1985 and 2015 (42.9%), and studies with a sample size of less than 100 (53.0%). CONCLUSIONS L pneumophila contamination in medical institutions is still very serious and should be paid attention to, especially in developed countries and hot water tanks.
Collapse
Affiliation(s)
- Zisi Fang
- School of Public Health, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Xiaocong Zhou
- School of Public Health, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Hui Liao
- School of Public Health, Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China
| | - Hong Xu
- Department of Environmental Health, Hangzhou Center for Disease Control and Prevention, Hangzhou, Zhejiang, China.
| |
Collapse
|
2
|
Krüger TIM, Herzog S, Mellmann A, Kuczius T. Impact of Chlorine Dioxide on Pathogenic Waterborne Microorganisms Occurring in Dental Chair Units. Microorganisms 2023; 11:1123. [PMID: 37317097 DOI: 10.3390/microorganisms11051123] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 04/21/2023] [Accepted: 04/22/2023] [Indexed: 06/16/2023] Open
Abstract
Bacterial contamination is a problem in dental unit water lines with the consequence of implementing regular disinfection. In this study, the short-term impact of chlorine dioxide (ClO2) treatment was investigated on the microorganisms Legionella pneumophila and L. anisa, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus. The environmental background was proven as an important factor regarding the tolerance to 0.4 mg/L ClO2 as saline and phosphate-buffered saline resulted in a higher bacterial reduction than tap water. Gram-positive microorganisms demonstrated higher robustness to ClO2 than Gram-negative, and microorganisms adapted to tap water showed increased stability compared to cultured cells. At high densities, substantial numbers of bacteria were able to withstand disinfection, whereby the use of 4.6 mg/L ClO2 increased the inactivation rate. A massive cell decrease occurred within the first 5 minutes with subsequent plateau formation or slowed cell reduction upon further exposure. This biphasic kinetics cannot be explained by a ClO2 depletion effect alone, because the probability of bacterial subpopulations with increased tolerance should be taken into account, too. Our results prove high disinfection efficiency to microorganisms that were rather found in correlation to the level of bacterial contamination and background solutions than the chosen concentration for ClO2 treatment itself.
Collapse
Affiliation(s)
| | - Susann Herzog
- Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany
| | - Alexander Mellmann
- Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany
| | - Thorsten Kuczius
- Institute of Hygiene, University Hospital Münster, Robert Koch-Straße 41, 48149 Münster, Germany
| |
Collapse
|
3
|
Lombardi A, Borriello T, De Rosa E, Di Duca F, Sorrentino M, Torre I, Montuori P, Trama U, Pennino F. Environmental Monitoring of Legionella in Hospitals in the Campania Region: A 5-Year Study. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2023; 20:ijerph20085526. [PMID: 37107807 PMCID: PMC10138562 DOI: 10.3390/ijerph20085526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 05/11/2023]
Abstract
Legionella is a pathogen that colonizes soils, freshwater, and building water systems. People who are most affected are those with immunodeficiencies, so it is necessary to monitor its presence in hospitals. The purpose of this study was to evaluate the presence of Legionella in water samples collected from hospitals in the Campania region, Southern Italy. A total of 3365 water samples were collected from January 2018 to December 2022 twice a year in hospital wards from taps and showers, tank bottoms, and air-treatment units. Microbiological analysis was conducted in accordance with the UNI EN ISO 11731:2017, and the correlations between the presence of Legionella and water temperature and residual chlorine were investigated. In total, 708 samples (21.0%) tested positive. The most represented species was L. pneumophila 2-14 (70.9%). The serogroups isolated were 1 (27.7%), 6 (24.5%), 8 (23.3%), 3 (18.9%), 5 (3.1%), and 10 (1.1%). Non-pneumophila Legionella spp. represented 1.4% of the total. Regarding temperature, the majority of Legionella positive samples were found in the temperature range of 26.0-40.9 °C. An influence of residual chlorine on the presence of the bacterium was observed, confirming that chlorine disinfection is effective for controlling contamination. The positivity for serogroups other than serogroup 1 suggested the need to continue environmental monitoring of Legionella and to focus on the clinical diagnosis of other serogroups.
Collapse
Affiliation(s)
- Annalisa Lombardi
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Tonia Borriello
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Elvira De Rosa
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Fabiana Di Duca
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Michele Sorrentino
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Ida Torre
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Paolo Montuori
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
| | - Ugo Trama
- General Directorate of Health, Campania Region, Centro Direzionale C3, 80143 Naples, Italy
| | - Francesca Pennino
- Department of Public Health, University “Federico II”, Via Sergio Pansini N° 5, 80131 Naples, Italy
- Correspondence:
| |
Collapse
|
4
|
Persistent contamination of a hospital hot water network by Legionellapneumophila. Int J Hyg Environ Health 2023; 250:114143. [PMID: 36907106 DOI: 10.1016/j.ijheh.2023.114143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 01/20/2023] [Accepted: 02/20/2023] [Indexed: 03/12/2023]
Abstract
OBJECTIVES We assessed the contamination with Legionella pneumophila (Lp) of the hot water network (HWN) of a hospital, mapped the risk of contamination, and evaluated the relatedness of isolates. We further validated phenotypically the biological features that could account for the contamination of the network. METHODS We collected 360 water samples from October 2017 to September 2018 in 36 sampling points of a HWN of a building from a hospital in France. Lp were quantified and identified with culture-based methods and serotyping. Lp concentrations were correlated with water temperature, date and location of isolation. Lp isolates were genotyped by pulsed-field gel electrophoresis and compared to a collection of isolates retrieved in the same HWN two years later, or in other HWN from the same hospital. RESULTS 207/360 (57.5%) samples were positive with Lp. In the hot water production system, Lp concentration was negatively associated with water temperature. In the distribution system, the risk of recovering Lp decreased when temperature was >55 °C (p < 10-3), the proportion of samples with Lp increased with distance from the production network (p < 10-3), and the risk of finding high loads of Lp increased 7.96 times in summer (p = 0.001). All Lp isolates (n = 135) were of serotype 3, and 134 (99.3%) shared the same pulsotype which is found two years later (Lp G). In vitro competition experiments showed that a 3-day culture of Lp G on agar inhibited the growth of a different pulsotype of Lp (Lp O) contaminating another HWN of the same hospital (p = 0.050). We also found that only Lp G survived to a 24h-incubation in water at 55 °C (p = 0.014). CONCLUSION We report here a persistent contamination with Lp of a hospital HWN. Lp concentrations were correlated with water temperature, season, and distance from the production system. Such persistent contamination could be due to biotic parameters such as intra-Legionella inhibition and tolerance to high temperature, but also to the non-optimal configuration of the HWN that prevented the maintenance of high temperature and optimal water circulation.
Collapse
|
5
|
Chlorine Dioxide: Friend or Foe for Cell Biomolecules? A Chemical Approach. Int J Mol Sci 2022; 23:ijms232415660. [PMID: 36555303 PMCID: PMC9779649 DOI: 10.3390/ijms232415660] [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: 10/26/2022] [Revised: 11/28/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022] Open
Abstract
This review examines the role of chlorine dioxide (ClO2) on inorganic compounds and cell biomolecules. As a disinfectant also present in drinking water, ClO2 helps to destroy bacteria, viruses, and some parasites. The Environmental Protection Agency EPA regulates the maximum concentration of chlorine dioxide in drinking water to be no more than 0.8 ppm. In any case, human consumption must be strictly regulated since, given its highly reactive nature, it can react with and oxidize many of the inorganic compounds found in natural waters. Simultaneously, chlorine dioxide reacts with natural organic matter in water, including humic and fulvic acids, forming oxidized organic compounds such as aldehydes and carboxylic acids, and rapidly oxidizes phenolic compounds, amines, amino acids, peptides, and proteins, as well as the nicotinamide adenine dinucleotide NADH, responsible for electron and proton exchange and energy production in all cells. The influence of ClO2 on biomolecules is derived from its interference with redox processes, modifying the electrochemical balances in mitochondrial and cell membranes. This discourages its use on an individual basis and without specialized monitoring by health professionals.
Collapse
|
6
|
Kermani M, Chegini Z, Mirkalantari S, Norzaee S. Assessment of the risk of Legionella pneumophila in water distribution systems in hospitals of Tehran city. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:842. [PMID: 36175694 DOI: 10.1007/s10661-022-10469-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Accepted: 09/10/2022] [Indexed: 06/16/2023]
Abstract
When a sensitive host inhales aerosols containing these bacteria, Legionella infection occurs. Therefore, monitoring and assessing Legionella in the environment and water distribution systems of such places are critical due to the prone population in hospitals. However, the health risks of Legionella bacteria in the environment are not adequately evaluated. In this study, for hospitalized patients, we performed a quantitative health risk assessment of Legionella in selected hospitals in Tehran city using two scenarios of shower and toilet faucet exposure. This study identified Legionella in 38 cases (38%) out of 100 samples collected from toilet faucets and showers in 8 hospitals. The information gathered was used for quantitative microbial risk assessment (QMRA). The microbial load transmitted by inhalation was calculated using the concentration of Legionella in water. Other exposure parameters (inhalation rate and exposure time) were obtained using information from other studies and the median length of hospital stay (3.6 days). The exponential model was used to estimate the risk of infection (γ = 0.06) due to Legionella pneumophila (L. pneumophila) inhalation for each exposure event. For the mean concentration obtained for Legionella (103 CFU/L), the risk of infection for toilet faucets and showers was in the range of 0.23-2.3 and 3.5-21.9, respectively, per 10,000 hospitalized patients. The results were compared with the tolerable risk level of infection determined by the US EPA and WHO. The risk values exceeded the WHO values for waterborne pathogens in hospitals in both exposure scenarios. As a result, our QMRA results based on monitoring data showed that despite using treated water (from distribution networks in the urban areas) by hospitals, 38% of the samples were contaminated with Legionella, and faucets and showers can be sources of Legionella transmission. Hence, to protect the health of hospitalized patients, the risk of Legionella infection should be considered.
Collapse
Affiliation(s)
- Majid Kermani
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran
| | - Zahra Chegini
- Department of Microbiology, School of Medicine, Hamadan University of Medical Sciences, Hamadan, Iran
| | - Shiva Mirkalantari
- Department of Microbiology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran.
| | - Samira Norzaee
- Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran.
- Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
7
|
Xu MY, Lin YL, Zhang TY, Hu CY, Tang YL, Deng J, Xu B. Chlorine dioxide-based oxidation processes for water purification:A review. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129195. [PMID: 35739725 DOI: 10.1016/j.jhazmat.2022.129195] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Revised: 05/14/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Chlorine dioxide (ClO2) has emerged as a broad-spectrum, safe, and effective disinfectant due to its high oxidation efficiency and reduced formation of organochlorinated by-products during application. This article provides an updated overview of ClO2-based oxidation processes used in water treatment. A systematic review of scientific information and experimental data on ClO2-based water purification procedures is presented. Concerning ClO2-based oxidation derivative problems, the pros and cons of ClO2-based combined processes are assessed and disinfection by-product (DBP) control approaches are proposed. The kinetic and mechanistic data on ClO2 reactivity towards micropollutants are discussed. ClO2 selectively reacts with electron-rich moieties (anilines, phenols, olefins, and amines) and eliminates certain inorganic ions and microorganisms with high efficiency. The formation of chlorite and chlorate during the oxidation process is a crucial concern when utilizing ClO2. Future applications include the combination of ClO2 with ferrous ions, activated carbon, ozone, UV, visible light, or persulfate processes. The combined process can reduce by-product generation while still ensuring ClO2 sterilization and disinfection. Overall, this research could provide useful information and new insights into the application of ClO2-based technologies.
Collapse
Affiliation(s)
- Meng-Yuan Xu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Yi-Li Lin
- Department of Safety, Health and Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung 824, Taiwan, ROC
| | - Tian-Yang Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Chen-Yan Hu
- College of Environmental and Chemical Engineering, Shanghai University of Electric Power, Shanghai 200090, PR China
| | - Yu-Lin Tang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China
| | - Jing Deng
- College of Civil Engineering, Zhejiang University of Technology, Hangzhou 310023, PR China
| | - Bin Xu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, PR China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, PR China.
| |
Collapse
|
8
|
Palcsó B, Kazsoki A, Herczegh A, Ghidán Á, Pinke B, Mészáros L, Zelkó R. Formulation of Chlorine-Dioxide-Releasing Nanofibers for Disinfection in Humid and CO 2-Rich Environment. NANOMATERIALS 2022; 12:nano12091481. [PMID: 35564190 PMCID: PMC9104377 DOI: 10.3390/nano12091481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/22/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022]
Abstract
Background: Preventing infectious diseases has become particularly relevant in the past few years. Therefore, antiseptics that are harmless and insusceptible to microbial resistance mechanisms are desired in medicine and public health. In our recent work, a poly(ethylene oxide)-based nanofibrous mat loaded with sodium chlorite was formulated. Methods: We tested the chlorine dioxide production and bacterial inactivation of the fibers in a medium, modeling the parameters of human exhaled air (ca. 5% (v/v) CO2, T = 37 °C, RH > 95%). The morphology and microstructure of the fibers were investigated via scanning electron microscopy and infrared spectroscopy. Results: Smooth-surfaced, nanoscale fibers were produced. The ClO2-producing ability of the fibers decreased from 65.8 ppm/mg to 4.8 ppm/mg with the increase of the sample weight from 1 to 30 mg. The effect of CO2 concentration and exposure time was also evaluated. The antibacterial activity of the fibers was tested in a 24 h experiment. The sodium-chlorite-loaded fibers showed substantial antibacterial activity. Conclusions: Chlorine dioxide was liberated into the gas phase in the presence of CO2 and water vapor, eliminating the bacteria. Sodium-chlorite-loaded nanofibers can be sources of prolonged chlorine dioxide production and subsequent pathogen inactivation in a CO2-rich and humid environment. Based on the results, further evaluation of the possible application of the formulation in face-mask filters as medical devices is encouraged.
Collapse
Affiliation(s)
- Barnabás Palcsó
- University Pharmacy Department of Pharmacy Administration, Faculty of Pharmaceutical Sciences, Semmelweis University, Hőgyes Endre utca 7-9, H-1092 Budapest, Hungary; (B.P.); (A.K.)
| | - Adrienn Kazsoki
- University Pharmacy Department of Pharmacy Administration, Faculty of Pharmaceutical Sciences, Semmelweis University, Hőgyes Endre utca 7-9, H-1092 Budapest, Hungary; (B.P.); (A.K.)
| | - Anna Herczegh
- Department of Conservative Dentistry, Faculty of Dentistry, Semmelweis University, Szentkirályi utca 47, H-1088 Budapest, Hungary;
| | - Ágoston Ghidán
- Institute of Medical Microbiology, Faculty of Medicine, Semmelweis University, Nagyvárad tér 4, H-1089 Budapest, Hungary;
| | - Balázs Pinke
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary; (B.P.); (L.M.)
| | - László Mészáros
- Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3, H-1111 Budapest, Hungary; (B.P.); (L.M.)
- MTA-BME Research Group for Composite Science and Technology, Műegyetem rkp. 3, H-1111 Budapest, Hungary
| | - Romána Zelkó
- University Pharmacy Department of Pharmacy Administration, Faculty of Pharmaceutical Sciences, Semmelweis University, Hőgyes Endre utca 7-9, H-1092 Budapest, Hungary; (B.P.); (A.K.)
- Correspondence: ; Tel.: +36-1-2170927
| |
Collapse
|
9
|
Gattuso G, Rizzo R, Lavoro A, Spoto V, Porciello G, Montagnese C, Cinà D, Cosentino A, Lombardo C, Mezzatesta ML, Salmeri M. Overview of the Clinical and Molecular Features of Legionella Pneumophila: Focus on Novel Surveillance and Diagnostic Strategies. Antibiotics (Basel) 2022; 11:370. [PMID: 35326833 PMCID: PMC8944609 DOI: 10.3390/antibiotics11030370] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/07/2022] [Accepted: 03/08/2022] [Indexed: 12/04/2022] Open
Abstract
Legionella pneumophila (L. pneumophila) is one of the most threatening nosocomial pathogens. The implementation of novel and more effective surveillance and diagnostic strategies is mandatory to prevent the occurrence of legionellosis outbreaks in hospital environments. On these bases, the present review is aimed to describe the main clinical and molecular features of L. pneumophila focusing attention on the latest findings on drug resistance mechanisms. In addition, a detailed description of the current guidelines for the disinfection and surveillance of the water systems is also provided. Finally, the diagnostic strategies available for the detection of Legionella spp. were critically reviewed, paying the attention to the description of the culture, serological and molecular methods as well as on the novel high-sensitive nucleic acid amplification systems, such as droplet digital PCR.
Collapse
Affiliation(s)
- Giuseppe Gattuso
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Roberta Rizzo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Alessandro Lavoro
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Vincenzoleo Spoto
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Giuseppe Porciello
- Epidemiology and Biostatistics Unit, National Cancer Institute IRCCS Fondazione G. Pascale, 80131 Naples, Italy; (G.P.); (C.M.)
| | - Concetta Montagnese
- Epidemiology and Biostatistics Unit, National Cancer Institute IRCCS Fondazione G. Pascale, 80131 Naples, Italy; (G.P.); (C.M.)
| | - Diana Cinà
- Health Management of the “Cannizzaro” Emergency Hospital of Catania, 95126 Catania, Italy;
- Clinical Pathology and Clinical Molecular Biology Unit, “Garibaldi Centro” Hospital, ARNAS Garibaldi, 95123 Catania, Italy
| | - Alessia Cosentino
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Cinzia Lombardo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Maria Lina Mezzatesta
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| | - Mario Salmeri
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy; (G.G.); (R.R.); (A.L.); (V.S.); (A.C.); (C.L.); (M.L.M.)
| |
Collapse
|
10
|
Abstract
Chlorine dioxide was produced by the reduction of chlorate with hydrogen peroxide in strongly acidic media. To avoid reaction interference during measuring procedures, UV spectra were acquired to monitor the chlorate reduction. This reduction led to the formation of chlorine dioxide and notable concentrations of chlorite and hypochlorous acid/chlorine, suggesting that the hydrogen peroxide:chlorate ratio is important. Once chlorates are transformed to chlorine dioxide, the surplus hydrogen peroxide promoted the further reaction of the chlorinated species down to less-important species. Moreover, chlorine dioxide was stripped with the outlet gas flow. A linear relationship was established between the amount of limiting reagent consumed and the maximum height of the absorption peak at 360 nm after testing with different ratios of hydrogen peroxide and chlorate, allowing calculations of the maximum amount of chlorine dioxide formed. To verify the reproducibility of the method, a test with four replicates was conducted in a hydrogen peroxide/chlorate solution where chlorine dioxide reduction was not promoted due to the presence of surplus chlorate in the reaction medium after the test. Results confirmed the efficient formation of this oxidant, with maximum concentrations of 8.0 ± 0.33 mmol L−1 in 400–450 min and a conversion percentage of 97.6%. Standard deviations of 0.14–0.49 mmol L−1 were obtained during oxidation (3.6–6.5% of the average), indicating good reproducibility.
Collapse
|
11
|
Jalili M, Ehrampoush MH, Zandi H, Ebrahimi AA, Mokhtari M, Samaei MR, Abbasi F. Risk assessment and disease burden of legionella presence in cooling towers of Iran's central hospitals. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:65945-65951. [PMID: 34327641 DOI: 10.1007/s11356-021-14791-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/27/2020] [Indexed: 06/13/2023]
Abstract
Regular monitoring and measurement of Legionella in tower water and preventive measures against contamination are particularly important in hospitals. This study aimed at risk assessment and disease burden because of legionella presence in cooling towers of Iran's central hospitals. Then its correlation with temperature, pH, turbidity, residual chlorine, and EC was investigated by the Pearson test. The health risk and burden of diseases caused by Legionella exposure were determined using QMRA and DALY models. Statistical analysis and modeling were performed in MATLAB2018. Of the total samples, 30-43% was infected with Legionella. The mean concentrations in hospital A and B were 5-102.5 ± 10 and 5-89.7 ± 0.7 CFU/L, respectively. Among environmental factors, turbidity and pH were the most effective factors in increasing and decreasing Legionella concentration, respectively. According to the QMRA model, the risks of Legionella infections and annual mortality in both hospitals were 0.2-0.3, 0-0.19, 2-2.9 × 10-5, and 0-0.7 × 10-5, respectively, which was higher than the acceptable risk range for Legionella (10-4-10-7). However, the trend of its change was negatively correlated with time (RB = - 0.77). According to the results, the concentration of Legionella and the exposure risk in both hospitals were higher than the permissible range, which is necessary to decrease to 0.1 current concentrations.
Collapse
Affiliation(s)
- Mahrokh Jalili
- Department of Environmental Health Engineering, Genetic and Environmental Adventures Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Student Research Committee, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
- Department of Environmental Health Engineering, Environmental Science and Technology Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mohammad Hassan Ehrampoush
- Department of Environmental Health Engineering, Genetic and Environmental Adventures Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Hengameh Zandi
- Department of Microbiology, School of Public Health, Research Center for Food Hygiene and Safety, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Ali Asghar Ebrahimi
- Department of Environmental Health Engineering, Genetic and Environmental Adventures Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mehdi Mokhtari
- Department of Environmental Health Engineering, Genetic and Environmental Adventures Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
| | - Mohammad Reza Samaei
- Department of Environmental Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fariba Abbasi
- Department of Environmental Health Engineering, School of Health, Shiraz University of Medical Sciences, Shiraz, Iran.
| |
Collapse
|
12
|
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.
Collapse
|
13
|
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.
Collapse
|
14
|
Pereira A, Silva AR, Melo LF. Legionella and Biofilms-Integrated Surveillance to Bridge Science and Real-Field Demands. Microorganisms 2021; 9:microorganisms9061212. [PMID: 34205095 PMCID: PMC8228026 DOI: 10.3390/microorganisms9061212] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/28/2021] [Accepted: 05/31/2021] [Indexed: 11/16/2022] Open
Abstract
Legionella is responsible for the life-threatening pneumonia commonly known as Legionnaires’ disease or legionellosis. Legionellosis is known to be preventable if proper measures are put into practice. Despite the efforts to improve preventive approaches, Legionella control remains one of the most challenging issues in the water treatment industry. Legionellosis incidence is on the rise and is expected to keep increasing as global challenges become a reality. This puts great emphasis on prevention, which must be grounded in strengthened Legionella management practices. Herein, an overview of field-based studies (the system as a test rig) is provided to unravel the common roots of research and the main contributions to Legionella’s understanding. The perpetuation of a water-focused monitoring approach and the importance of protozoa and biofilms will then be discussed as bottom-line questions for reliable Legionella real-field surveillance. Finally, an integrated monitoring model is proposed to study and control Legionella in water systems by combining discrete and continuous information about water and biofilm. Although the successful implementation of such a model requires a broader discussion across the scientific community and practitioners, this might be a starting point to build more consistent Legionella management strategies that can effectively mitigate legionellosis risks by reinforcing a pro-active Legionella prevention philosophy.
Collapse
|
15
|
Abstract
BACKGROUND Legionnaires' disease (LD) occurs predominantly in adults and elderly people. Its incidence in Europe has been increasing in recent years. It is rare in younger age groups and prone to be reported as healthcare-associated infection with a higher risk of fatal outcome. Hospital-acquired LD is mostly associated with a colonized hospital water system. We describe 5 LD cases in a children's hospital in Slovakia, subsequent environmental investigation, control measures, and 5-year monitoring of Legionella colonization in hospital's water system. METHODS In 2014-2019, we tested clinical specimens from 75 hospitalized patients. Respiratory samples were cultured for Legionella, patient's urine was tested for Legionella urinary antigens, and the microagglutination test was used for serologic testing. Samples of water were collected in 2015-2019 and processed according ISO11731. RESULTS We identified 5 Legionella infections in 2014-2015. Median age of patients was 15 years. All were high-risk patients hospitalized for their underlying diseases. All patients required admission to intensive care unit, and artificial ventilation due to general deterioration and respiratory failure. Legionella pneumophila was isolated from 72% of water samples. Chlorine dioxide dosing into water system above 0.3 ppm caused significant decrease of Legionella concentration in water samples. Samples taken from outlets with antimicrobial filter installed were legionellae-negative. CONCLUSIONS Control measures led to decreased risk of infection, but not to eradication of Legionellae. It is necessary to extend the diagnostics for Legionella infection in hospitalized children with pneumonia, especially in hospitals with colonized water system.
Collapse
|
16
|
Bertolino G, Marras L, Sanna C, Carrucciu G, Schintu M, Coroneo V. Ten-Year Retrospective Analysis of Legionella Diffusion in Hospital Water Systems and Its Serogroup Seasonal Variation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1282:93-103. [PMID: 32030638 DOI: 10.1007/5584_2020_484] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION Legionella spp. are ubiquitous aquatic organisms found to be associated with community-acquired pneumoniae (CAP) as well as hospital-acquired pneumonia (HAP). Direct inhalation of aerosols from environmental colonisation is typically the source of infection. The aim of this study was to determine the level of colonisation in hospital water supply systems in order to assess the criticality of the water distribution network and strengthen preventive measures. METHODS From 2009 to 2018, 769 water samples were collected and then analysed according to the standard methods indicated in ISO11731-2:2004 and ISO11731:2017 for Legionella detection. RESULTS The samples were positive in 37.1% cases (n. 285) and negative in 62.9% cases (n. 484). The threshold of 10,000 CFU/L was exceeded in 15.1% cases and led to decolonisation as indicated by Italian and European ECDC guidelines. In the autumn-winter period SG1 showed a positivity of 41.2% (n. 40) with a decrease in the spring-summer period with 9.6% (n. 18) of positivity. In contrast, SG2-15 showed a positivity of 30.9% (n. 30) in autumn-winter, which tends to increase to 56.9% (n. 112) in spring-summer (p < 0.001). CONCLUSION Surprisingly, besides showing a seasonal trend already described previously in the literature, the positivity of our sample was not balanced even for serogroups in the two periods. This could be due to genetic differences and ecological niches to be further investigated that could also have links with the greater pathogenicity of SG1. Environmental microbiological surveillance and risk assessment should be performed more frequently and disinfection must be carried out, especially in health facilities where people are more susceptible to infections.
Collapse
Affiliation(s)
- Giacomo Bertolino
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy. .,Pharmaceutical Department, ATS Sardegna, ASSL Cagliari, Cagliari, Italy.
| | - Luisa Marras
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Clara Sanna
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Gerolamo Carrucciu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Marco Schintu
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| | - Valentina Coroneo
- Department of Medical Sciences and Public Health, University of Cagliari, Cagliari, Italy
| |
Collapse
|
17
|
Vertova A, Miani A, Lesma G, Rondinini S, Minguzzi A, Falciola L, Ortenzi MA. Chlorine Dioxide Degradation Issues on Metal and Plastic Water Pipes Tested in Parallel in a Semi-Closed System. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16224582. [PMID: 31752399 PMCID: PMC6888174 DOI: 10.3390/ijerph16224582] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 11/14/2019] [Accepted: 11/15/2019] [Indexed: 11/16/2022]
Abstract
Chlorine dioxide (ClO2) has been widely used as a disinfectant in drinking water in the past but its effects on water pipes have not been investigated deeply, mainly due to the difficult experimental set-up required to simulate real-life water pipe conditions. In the present paper, four different kinds of water pipes, two based on plastics, namely random polypropylene (PPR) and polyethylene of raised temperature (PERT/aluminum multilayer), and two made of metals, i.e., copper and galvanized steel, were put in a semi-closed system where ClO2 was dosed continuously. The semi-closed system allowed for the simulation of real ClO2 concentrations in common water distribution systems and to simulate the presence of pipes made with different materials from the source of water to the tap. Results show that ClO2 has a deep effect on all the materials tested (plastics and metals) and that severe damage occurs due to its strong oxidizing power in terms of surface chemical modification of metals and progressive cracking of plastics. These phenomena could in turn become an issue for the health and safety of drinking water due to progressive leakage of degraded products in the water.
Collapse
Affiliation(s)
- Alberto Vertova
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy; (A.V.); (G.L.); (S.R.); (A.M.); (L.F.)
| | - Alessandro Miani
- Department of Environmental Science and Policy (ESP), Università degli Studi di Milano, Via Celoria 2-20133 Milan, Italy;
- Italian Society of Environmental Medicine (SIMA), Via Monte Leone 2-20149 Milan, Italy
| | - Giordano Lesma
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy; (A.V.); (G.L.); (S.R.); (A.M.); (L.F.)
- CRC Materiali Polimerici (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy
| | - Sandra Rondinini
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy; (A.V.); (G.L.); (S.R.); (A.M.); (L.F.)
| | - Alessandro Minguzzi
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy; (A.V.); (G.L.); (S.R.); (A.M.); (L.F.)
| | - Luigi Falciola
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy; (A.V.); (G.L.); (S.R.); (A.M.); (L.F.)
- Italian Society of Environmental Medicine (SIMA), Via Monte Leone 2-20149 Milan, Italy
| | - Marco Aldo Ortenzi
- Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy; (A.V.); (G.L.); (S.R.); (A.M.); (L.F.)
- CRC Materiali Polimerici (LaMPo), Department of Chemistry, Università degli Studi di Milano, Via Golgi 19-20133 Milan, Italy
- Correspondence: ; Tel.: +39-0250314135
| |
Collapse
|