Erfahrungsberichte zur Anwendung von Chlordioxid zur Inaktivierung von Legionella
Lin, Y.E.; Stout, J.E.; Yu, V.L. Controlling Legionella in
hospital drinking water: An evidence-based review of disinfection methods. Infect.
Control Hosp. Epidemiol. 2011, 32,
166–173. [Google Scholar] [CrossRef]
Abstract
Hospital-acquired
Legionnaires' disease is directly linked to the presence of Legionella in
hospital drinking water. Disinfecting the drinking water system is an effective
preventive measure. The efficacy of any disinfection measures should be
validated in a stepwise fashion from laboratory assessment to a controlled
multiple-hospital evaluation over a prolonged period of time. In this review,
we evaluate systemic disinfection methods (copper-silver ionization, chlorine
dioxide, monochloramine, ultraviolet light, and hyperchlorination), a focal
disinfection method (point-of-use filtration), and short-term disinfection
methods in outbreak situations (superheat-and-flush with or without
hyperchlorination). The infection control practitioner should take the lead in
selection of the disinfection system and the vendor. Formal appraisals by other
hospitals with experience of the system under consideration is indicated.
Routine performance of surveillance cultures of drinking water to detect
Legionella and monitoring of disinfectant concentrations are necessary to
ensure long-term efficacy.
Yusen E. Lin, PhD, MBA; Janet E. Stout, PhD; Victor L. Yu, MD
Published in: infection control and hospital epidemiology february 2011, vol. 32, no.2
Chlorine
Dioxide
Mechanism of action and
method of application. Chlorine dioxide
has been used for water treatment in Europe since the 1940s, and numerous
systems have been installed in the United States for Legionella disinfection.
Chlorine dioxide is a gas in solution that is typically generated on site at
the facility. Methods for producing chlorine dioxide include controlled mixing
of chemical precursors or electrochemical generation. A limited number of
controlled prospective evaluations have been published.
Field evaluation.
The first controlled field
evaluation in the United States was conducted in a hospital where cases of hospital-acquired
Legionnaires’ disease had occurred. During
the 15 months following the installation, the percentage of hot water outlets
with Legionella positivity significantly
decreased, from 23% to 12%, and the Legionella positivity
rate for cold water taps
approached 0%. The average chlorine dioxide residual measured at hot water taps
was 0.08 mg/L, which was 88% lower than that measured at the cold water reservoir
(0.68 mg/L). The mean chlorine dioxide residual
concentration at cold
water outlets was 0.33 mg/L. The reduction in the chlorine dioxide
concentration in the hot water (0.08 mg/L) may explain why complete eradication
was not achieved until after 20 months of
treatment.
In a 30-month prospective study, Zhang et al evaluated the efficacy of chlorine dioxide disinfection in a New York hospital.
The Legionella positivity rate for hot water outlets decreased from 60% to 10%. It required 18 months to achieve a significant reduction in the Legionella positivity rate for hot water outlets. No cases of hospital-acquired legionellosis were identified in the post disinfection period.
Significantly lower chlorine dioxide residual concentrations were detected in hot water (0.04 mg/L) than in cold water (0.3–0.5 mg/L).
Confirmatory reports.
An evaluation of chlorine dioxide disinfection
was conducted in a 1,000-bed hospital in the United Kingdom. After 2 years of
chlorine dioxide treatment (target concentration, 0.5 mg/L), the Legionella positivity rate remained unchanged, and 2
cases of hospital-acquired Legionnaires’ disease had occurred.
In
a northern United Kingdom hospital where hospital-acquired Legionnaires’ dis-
ease had occurred, chlorine
dioxide disinfection was initi- ated because of repeated failures with
hyperchlorination.
Chlorine dioxide at a concentration of 0.25–0.5 mg/L was minjected into the cold water supply. However, 3–5 mg/L of chlorine dioxide injected into the hot water supply was required to achieve a 0.25–0.5 mg/L residual concentration at hot water taps. After 3 years, Legionella was not detectable in the water system. It is note worthy that on 2 occasions when the chlorine dioxide concentration fell below 0.25 mg/ L because of mechanical failure, Legionella was detected in water samples within 4 days.
In an Italian hospital, chlorine dioxide was injected into the hospital water system at a concentration of 0.4–0.5 mg/L at the source, which resulted in a concentration of 0.2–0.3 mg/L at the water outlets. After 4 years of treatment, high concentrations of Legionella were still detected, and 12 cases of hospital-acquired Legionnaires’ disease had occurred. The authors concluded that chlorine dioxide was not useful.
In a Scottish hospital,hyperchlorination was ineffective in
eradicating L. pneumophila from the hospital
drinking water, and cases of hospital-acquired legionellosis occurred. Chlorine
dioxide at a concentration of 0.5 mg/L was injected into the cold water system.
L. pneumophila serogroup 1 was not detectable by week 6. However,
Legionella anisa persisted in low numbers. Investigators from Johns Hopkins University Hospital reported that chlorine dioxide disinfection reduced the L. anisa positivity rate after 17 months. There were caveats: a prolonged duration of treatment was necessary before the L. anisa positivity rate decreased significantly; it took 60 days to drop from 40% to 20% of water outlets and another 15 months to reach the 4% level achieved at the end of their study period.
Moreover, Legionnaires’ disease caused by L. anisa is extremely rare. In a survey from the French national Legionella surveillance network, 13.8% of environmental samples were positive for L. anisa and only 0.8% of patient samples were positive for L. anisa.
In a multicenter prospective study in-volving 20 hospitals across the United States, 45% of hospitals were colonized with L. anisa, but no infections caused by L. anisa were identified; thus, we do not recommend disinfection if L.anisa is the sole Legionella species isolated fromthe water.
Advantages and disadvantages.
Chlorine dioxide has superior penetration into biofilms than chlorine.
By-products, such as chlorite and chlorate, are not carcinogenic. Biocidal action is maintained over a wider range of pH than for chlorine and copper-silver ionization. Corrosive effects are much less than those of chlorine.
The limits of chlorine dioxide disinfection include the following.
First, a prolonged time is
necessary to demonstrate significant reductions in the Legionella positivity rate.
Second, the residual
concentration in hot water is low (!0.1mg/L) when the chlorine dioxide is
injected into the incoming cold water
at a concentration of 0.5–0.8 mg/L.
Third, reactions with organic material and corrosion scale in piping can cause rapid conversion of chlorine dioxide to its byproducts, chlorite and chlorate. These by-products may pose health risks for consumers. Fourth, corrosion of galvanized pipes can cause loss of chlorine dioxide by reaction with magnetite (Fe304); this may affect efficacy.
The major challenge for
chlorine dioxide is maintenance of an effective residual concentration (0.3–0.5
mg/L) throughout the drinking water system.
One New York hospital achieved a concentration of greater than 0.1 mg/L by direct injection into the hot water system (J.E.S., personal communication, 2010).
Chlorine dioxide is a
registered biocide with the EPA; it has set the maximum residual disinfectant
level for chlorine dioxide at 0.8 mg/L and set the maximum contaminant level for
chlorite at 1.0 mg/L.
Chlorite may cause
congenital cardiac defects and hemolytic anemia.
Chlorate is currently not regulated because of the lack of health data for setting maximum contaminant level.
The United Kingdom Drinking Water Inspectorate specifies a
maximum value of 0.5 mg/L for all oxidants in drinking water, which is the
combined concentration of chlorine dioxide, chlorite, and chlorate.
In 2004, the EPA
mandated that any healthcare facility adding a disinfectant to a water system
that serves at least 25 people is considered a public water system and must
comply with the Safe Drinking Water Act and Stage 1 Disinfection Byproducts
Rule.
All chlorine dioxide products used in hospitals must be registered with the EPA and certified by the American National Standards Institute and National Sanitation Foundation. Some states require regular monitoring of chlorine dioxide and chlorite levels. Such testing can be costly, and this expense is often overlooked.
Cost.
One hospital estimated the cost of engineering
measures for chlorine dioxide disinfection to be approximately,$50,000 per
year.
The annual cost for operation and maintenance of 2 chlorine dioxide units for a 438-bed hospital was approximately $34,000 per year. Installation costs were not included, because the hospital leased the chlorine dioxide units and hospital personnel installed the equipment. The annual cost for monitoring the chlorine dioxide residual concentration and the chlorite level in the hospital water system ranged from $3,000 to $5,000, with a total annual cost of $40,000.
Summary.
Chlorine dioxide is a
promising disinfection modality; however, it has not yet fulfilled the 4
criteria required for validation of efficacy (Table 1).
We are optimistic that the challenges for chlorine dioxide disinfection will be overcome. For now, we would recommend it in circumstances that favor efficacy, including a smaller secondary distribution system, a low cold water temperature, nongalvanized piping, and low total organic carbon content in the hospital water.
In future published
studies, chlorine dioxide concentrations in concert with Legionella positivity
rate should be reported.
Given the many vendors offering varying types of chlorine dioxide generators and the marginal success experienced by so many hospitals, recommendations and assessments from other hospitals with experience with chlorine dioxide would seem mandatory.
++++++++++++++++++++++++++++
Legionella control by chlorine dioxide in hospital water system
Zhang, Z.; Mccann, C.; Hanrahan, J.; Jencson, A.; Joyce, D.; Fyffe, S.; Piesczynski, S.; Hawks, R.; Stout, J.E. Legionella control by chlorine dioxide in hospital water systems. J. Am. Water Work. Assoc. AWWA 2009, 101, 117–127. [Google Scholar] [CrossRef]
https://awwa.onlinelibrary.wiley.com/doi/10.1002/j.1551-8833.2009.tb09894.x
Peer Reviewed
Legionella control by chlorine dioxide in hospital water
systems
Zhe Zhang,Carole McCann
(Deceased),Jennifer Hanrahan,Annette Jencson,Daniel Joyce,Steven Fyffe,Steve
Piesczynski,Robert Hawks,Janet E. Stout,Victor L. Yu,Radisav D. Vidic
First published: 01 May 2009 First published: 01 May 2009
https://doi.org/10.1002/j.1551-8833.2009.tb09894.x
Citations: 17
Abstrakt
Diese Studie bewertete
die Sicherheit und Wirksamkeit von Chlordioxid (ClO2), das in die eingehende
Hauptwasserleitung eingespeist wurde, um Legionella-Bakterien in zwei
Krankenhauswassersystemen zu bekämpfen. In beiden Krankenhäusern A und B sank
die Positivität aller distalen Abflüsse (Waschbecken und Duschen) für
Legionellen nach der ClO2-Behandlung von 60 % auf ≤ 10 %. In Krankenhaus B
wurde die Keimzahl der heterotrophen Platten in heißem Wasser nach der
ClO2-Behandlung von 15.400 KBE/ml auf 2.900 KBE/ml reduziert. Die mittleren
Konzentrationen von ClO2 und Chlorit (ClO2 -) in kaltem und heißem Wasser
überstiegen nicht die maximale Restdesinfektionskonzentration von 0,8 mg/l bzw.
die maximale Schadstoffkonzentration von 1,0 mg/l. In diesen beiden
Krankenhäusern wurden in der Zeit nach der Desinfektion keine Fälle von
medizinisch erworbener Legionellose festgestellt. Die Studie zeigt, dass ClO2
ein vielversprechendes Desinfektionsmittel ist, um nicht nur Legionellen, sondern
auch andere Mikroorganismen im Trinkwasser zu bekämpfen
· Environmental Management of Legionella in Domestic Water Systems: Consolidated and Innovative Approaches for Disinfection Methods and Risk Assessment, Microorganisms, 10.3390/microorganisms9030577, 9, 3, (577), (2021)
· Legionella: A Promising Supplementary Indicator of Microbial Drinking Water Quality in Municipal Engineered Water Systems, Frontiers in Environmental Science, 10.3389/fenvs.2021.684319, 9, (2021)
· Control of Legionella in hospital potable water systems, Decontamination in Hospitals and Healthcare, 10.1016/B978-0-08-102565-9.00004-2, (71-100), (2020).
· Successful Prevention of Nosocomial Legionellosis by Best Water Management adopting an integrated system of pre-filters, filters, pipe protecting products, remote control and chlorine dioxide-based disinfection system, Journal of Hospital Infection, 10.1016/j.jhin.2020.05.002, (2020)
· Knowledge gaps and risks associated with premise plumbing drinking water quality, AWWA Water Science, 10.1002/aws2.1177, 2, 3, (2020).
· Legionnaires’ Disease in Pediatric Patients, Control Measures and 5-Year Follow-up, Pediatric Infectious Disease Journal, 10.1097/INF.0000000000002781, 39, 11, (990-994), (2020).
· Legionellosis and Recent Advances in Technologies for Legionella Control in Premise Plumbing Systems: A Review, Water, 10.3390/w12030676, 12, 3, (676), (2020).
· Assessment of the Legionnaires’ disease outbreak in Flint, Michigan, Proceedings of the National Academy of Sciences, 10.1073/pnas.1718679115, 115, 8, (E1730-E1739), (2018)
· Methodological approaches for monitoring opportunistic pathogens in premise plumbing: A review, Water Research, 10.1016/j.watres.2017.03.046, 117, (68-86), (2017).
· Efficacy of chlorine dioxide disinfection to non-fermentative Gram-negative bacilli and non-tuberculous mycobacteria in a hospital water system, Journal of Hospital Infection, 10.1016/j.jhin.2016.01.005, 93, 1, (22-28), (2016).
· Water Safety and Legionella in Health Care, Infectious Disease Clinics of North America, 10.1016/j.idc.2016.04.004, 30, 3, (689-712), (2016).
· Evaluation of a New Monochloramine Generation System for Controlling Legionella in Building Hot Water Systems , Infection Control & Hospital Epidemiology, 10.1086/678418, 35, 11, (1356-1363), (2016).
· The impact of material surface roughness and temperature on the adhesion of Legionella pneumophila to contact surfaces , International Journal of Environmental Health Research, 10.1080/09603123.2014.963035, 25, 5, (469-479), (2014)
· Maintaining Legionella control in building water systems, Journal AWWA, 10.5942/jawwa.2014.106.0147, 106, 10, (24-32), (2014).
· Probiotic Approach to Pathogen Control in Premise Plumbing Systems? A Review, Environmental Science & Technology, 10.1021/es402455r, 47, 18, (10117-10128), (2013)
· Comprehensive Evaluation of Biological Growth Control by Chlorine-Based Biocides in Power Plant Cooling Systems Using Tertiary Effluent, Environmental Engineering Science, 10.1089/ees.2012.0502, 30, 6, (324-332), (2013).
· Legionellae in engineered systems and use of quantitative microbial risk assessment to predict exposure, Water Research, 10.1016/j.watres.2011.12.022, 46, 4, (921-933), (2012).
+++++++++++++++++++++++++++++++++++++++++++++++
3. Effectiveness of different methods to control legionella in the water supply: Ten-year experience in an Italian university hospital
Marchesi, I.;
Marchegiano, P.; Bargellini, A.; Cencetti, S.; Frezza, G.; Miselli, M.;
Borella, P. Effectiveness of different methods to control legionella in the
water supply: Ten-year experience in an Italian university hospital. J.
Hosp. Infect. 2011, 77, 47–51. [Google Scholar] [CrossRef] [PubMed]
https://www.journalofhospitalinfection.com/article/S0195-6701(10)00405-6/references
Effectiveness of different methods to control
legionella in the water supply: Ten-year experience in an Italian university
hospital
- January 2011 The Journal of hospital
infection 77(1):47-51 DOI:10.1016/j.jhin.2010.09.012 PubMed
Authors:
Isabella Marchesi Università degli Studi di Modena e Reggio
EmiliaPatrizia Marchegiano Polyclinic of Modena Annalisa BargelliniUniversità degli Studi di Modena e Reggio
Emilia S Cencetti G Frezza M Miselli Paola Borella Università degli Studi di Modena e Reggio
Emilia
Abstract
We report our ten-year experience of hyperchlorination, thermal shock, chlorine dioxide, monochloramine, boilers and point-of-use filters for controlling legionella contamination in a hospital hot water distribution system.
Shock disinfections were associated with a return to pretreatment contamination levels within one or two months. We found that chlorine dioxide successfully maintained levels at <100 cfu/L, whilst preliminary experiments gave satisfactory results with monochloramine.
No contamination was observed applying point-of-use filters and electric boilers at temperatures of >58°C and no cases of nosocomial legionellosis were detected in the ten-year observation period.
Our performance ranking in reducing legionella contamination was filter, boiler, chlorine dioxide, hyperchlorination and thermal shock. Chlorine dioxide was the least expensive procedure followed by thermal shock, hyperchlorination, boiler and filter. We suggest adopting chlorine dioxide and electric boilers in parallel.
+++++++++++++++++++++++++++++++++++++++
4.
o Long-term effects of hospital water network disinfection on Legionella and other waterborne bacteria in an Italian University Hospital.
Casini, B.; Buzzigoli,
A.; Cristina, M.L.; Spagnolo, A.M.; DelGiudice, P.; Brusaferro, S.; Poscia, A.;
Moscato, U.; Valentini, P.; Baggiani, A.; et al. Long-term effects of hospital
water network disinfection on Legionella and other waterborne bacteria in an
Italian University Hospital. Infect. Control Hosp. Epidemiol. 2014, 35,
293–299. [Google Scholar] [CrossRef]
https://pubmed.ncbi.nlm.nih.gov/24521596/
Infect Control Hosp Epidemiologie Epub 2014 Feb 3.
Beatrice Casini 1, Andrea Buzzigoli, Maria Luisa Cristina, Anna Maria Spagnolo, Pietro Del Giudice, Silvio Brusaferro, Andrea Poscia, Umberto Moscato, Paola Valentini, Angelo Baggiani, Gaetano Privitera
Affiliations expand PMID: 24521596
DOI: 10.1086/675280
Abstract
Objective and design:
Legionella control
still remains a critical issue in healthcare settings where the preferred
approach to health risk assessment and management is to develop a water safety
plan. We report the experience of a university hospital, where a water safety
plan has been applied since 2002, and the results obtained with the application
of different methods for disinfecting hot water distribution systems in order
to provide guidance for the management of water risk.
Interventions:
The disinfection
procedures included continuous chlorination with chlorine dioxide (0.4-0.6 mg/L
in recirculation loops) reinforced by endpoint filtration in critical areas and
a water treatment based on monochloramine (2-3 mg/L). Real-time polymerase
chain reaction and a new immunoseparation and adenosine triphosphate
bioluminescence analysis were applied in environmental monitoring.
Results: After 9 years, the integrated disinfection-filtration strategy significantly reduced positive sites by 55% and the mean count by 78% (P < .05); however, the high costs and the occurrence of a chlorine-tolerant clone belonging to Legionella pneumophila ST269 prompted us to test a new disinfectant.
The shift to
monochloramine allowed us to eliminate planktonic Legionella and did not
require additional endpoint filtration; however, nontuberculous mycobacteria
were isolated more frequently as long as the monochloramine concentration was 2
mg/L; their cultivability was never regained by increasing the concentration up
to 3 mg/L.
Conclusions:
Any disinfection method
needs to be adjusted/fine-tuned in individual hospitals in order to maintain
satisfactory results over time, and only a locally adapted evidence-based
approach allows assessment of the efficacy and disadvantages of the control
measures.
Keine Kommentare:
Kommentar veröffentlichen