scientific fact file legionella contamination in...

SCIENTIFIC FACT FILE LEGIONELLA CONTAMINATION IN WATER SUPPLY SYSTEMS

AND APPLICATION OF ECAS-ANOLYTE

ECAS 4 S.R.L. | BOLOGNA | ITALY

____________________________________________________________________________________________SCIENTIFIC FACT FILE – LEGIONELLA CONTAMINATION IN WATER SUPPLY SYSTEMS AND APPLICATION OF ECAS-ANOLYTE

1

SCIENTIFIC FACT FILE LEGIONELLA CONTAMINATION IN WATER SUPPLY SYSTEMS AND APPLICATION OF ECAS-ANOLYTE

1 EFFICACY ASSESSMENT OF THE HYDROSTEL® WATER DISINFECTING SYSTEM - RELATED TO THE DECREASE OF LEGIONELLA CONTAMINATION IN A DRINKING WATER HEATING SYSTEM OF ST. MARIEN HOSPITAL IN BONN ____________________________________________________

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ST. PLEISCHL, M. EXNER, PUBLIC HEALTH AND HYGIENE INSTITUTE AT BONN UNIVERSITY, WHO COLLABORATING CENTRE FOR HEALTH PRO-MOTING WATER MANAGEMENT & RISK COMMUNICATION BONN, GERMANY MAY 2005

1.1 ABSTRACT ________________________________________________________________________________________________ 2 1.2 TABLES ___________________________________________________________________________________________________ 3

2 SANIFICATION OF DRINKING WATER BY MEANS OF ELECTRO-CHEMICAL ACTIVATION ____ 4

L. JATZWAUK, DRESDEN UNIVERSITY HOSPITAL DRESDEN, GERMANY MAY 2007

2.1 ABSTRACT ________________________________________________________________________________________________ 4 2.2 TABLES ___________________________________________________________________________________________________ 5

3 EVALUATION OF TWO DISINFECTION SYSTEMS FOR LEGIONELLA ERADICATION FROM A HOSPITAL WATER SUPPLY _____________________________________________________________

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L. FRANZIN, AMEDEO DI SAVOIA HOSPITAL, ASL TO2 TURIN, ITALY MAY 2008

3.1 ABSTRACT ________________________________________________________________________________________________ 6 3.2 TABLES ___________________________________________________________________________________________________ 7

4 IMPACT OF A NEW ELECTRO CHEMICAL ACTIVATION SYSTEM FOR WATER DISINFECTION ON LEGIONELLA PNEUMOPHILA ISOLATION IN HOSPITAL POTABLE WATER SYSTEMS _______

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J.M.RIVERA, PREVENTIVE MEDICINE DEPARTMENT, SCHOOL OF MEDI-CINE, UNIVERSIDAD COMPLUTENSE MADRID, SPAIN SEPTEMBER 2008

4.1 ABSTRACT ________________________________________________________________________________________________ 8 4.2 TABLES ___________________________________________________________________________________________________ 9

________________________________________________________________________________________ SCIENTIFIC FACT FILE – LEGIONELLA CONTAMINATION IN WATER SUPPLY SYSTEMS AND APPLICATION OF ECAS-ANOLYTE

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1.1 Abstract

Efficacy assessment of the Hydrostel® water disinfec-ting system - related to the decrease of Legionella

contamination in a drinking water heating system of St. Marien hospital in Bonn

St. Pleischl, M. Exner, Public Health and Hygiene Institute at Bonn University, WHO Collaborating Centre for Health Promoting Water Management & Risk Communication , Bonn,

Germany

May 2005

Background: The highly ramified and extended water piping of St. Marien Hospital in Bonn has been periodically inspected for Legionella in the past. The concentration of Legionella found in the hot water system repeatedly exceeded the recommendations contained in DVGW W 551; in order to temporarily reduce the concentration of Legionella, the hot water systems were periodi-cally heated to hot temperature; the issuance of hot water (over 70°C) from all taps in order to eli-minate all contaminations was not possible for logistic reasons. Since continuous temperature in-crease was not feasible for economic and technical reasons, it was chosen to adopt a Hydrostel-WDS positioned in the cold water station of the hospital to lower the concentration of Legionella to under the recommended threshold of 100 cfu/100 ml. Methods: According to the manufacturer’s indications, the water disinfection system (WDS) produces an active substance called “Anolyte“ (Hydrostel procedure) which is injected in a con-centration by volume of 0.3 - 0.8% into the water subjected to the treatment. Anolyte is produced on-site by means of an electrochemical method from a 0.5% sodium chloride solution previously produced using a saturated solution of salt and softened water. Anolyte is collected in a back-up container (to provide for the system needs) and then injected into the pipes by a piston membrane dispensing pump according to the amount of water subjected to the treatment. The dispensing operation is monitored by a contact water meter. By means of the implemented control functions (electrical conductivity, electrical current constancy), the manufacturer ensures the correct opera-tion of the 0.5% sodium chloride solution and the production of Anolyte.

Results: A decrease in the concentration of Legionella at all taps was found immediately af-ter installing the disinfecting system in the drinking water heating system of the central buil-ding/paediatric ward. Follow-up measurements performed after one month and after three mon-ths confirmed the success of the intervention. It was suggested to keep the Hydrostel WDS running in the building in the future and to monitor system efficiency at longer intervals. The positioning of the system in the cold water station was too far away from the target, i.e. the drinking water hea-ting system of the central building/paediatric ward. As per §11 of the “Trinkwasserverordnung 2001” [German Drinking Water Code], the required concentrations of Anolyte in the cold water would not be allowed on the long term. Alternatively, a possible treatment with a lower concentration of Anolyte for a longer time was deemed not advisable due to the waiting time and the high concen-tration of Legionella. After starting up the Hydrostel WDS system, efficiency with considerably lower concentrations of Anolyte were obtained, supporting the initial hypothesis of being able to provide appropriate metering by using two separate systems. A decrease in concentration is currently in progress to ensure a maximum value of 0.3 mg/l of free chlorine at all taps as determined by the “Trinkwasserverordnung 2001”. According to our experience, this objective is feasible: long-term success will be validated by further controls.

Conclusions: As this analysis shows, it was possible to considerably decrease the concentra-tions of Legionella bacteria in the hot water piping of the central building/paediatric ward by means of 0.2 - 0.5 mg/l concentrations of Anolyte (measured as free chlorine).


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1.2 Tables

1.2.1 Table - Results of Legionella monitoring in St.Marien Hospital during the installation of the

water disinfection system Hydrostel®.

1.2.2 Figure - Graphical representation of table from above, regarding detected amounts of

Legionella.

4th floor Hildegard 3rd floor Elisabeth

Ground Intensive 3rd floor Michael

2nd floor Josef Sterilization

3rd floor Winfried General Circulation

Circulation Ped.

0

5.000

10.000

15.000

20.000

25.000

31.03

.04

30.04

.04

31.05

.04

30.06

.04

31.07

.04

31.08

.04

30.09

.04

31.10

.04

30.11

.04

31.12

.04

31.01

.05

28.02

.05

31.03

.05

Datecfu/

100mL °C cfu/100mL °C cfu/




100mL °C31.03.04 1.400 58 1.400 5019.05.04 2.600 55 3.600 5030.09.04 4.400 43 3.100 46 4.800 54 4.800 54 0 52 1.400 52 0 52 1.030 5206.10.0413.10.04 7.900 44 460 56 60 56 2.400 5220.10.04 23.000 38 320 55 9 55 3.500 4928.10.04 133 49 470 5209.11.04 22.400 43 370 53 17 54 6.800 5318.11.04 6.400 44 0 5502.12.04 2.900 42 7.300 43 7.600 46 2.200 53 0 5316.12.04 13.400 43 10.100 43 14.400 47 3.500 53 0 5301.01.0513.01.05 0 44 1 46 0 48 0 56 0 58 0 4809.02.05 0 57 0 58 1 48 0 56 0 57 0 5113.04.05 0 57 0 58 6 54 7 57 0 58 123 50 1 50 9 54 17 52

Building Antonio Technical room

startup of the unit on the general cold water supply

transfer of the unit to the hot water circulation line of pediatric ward

general circulation circulation ped.

Central building

4th floor Hildegard 3rd floor Elisabeth Ground Intensive 3rd floor Michael 2nd floor Josef sterilization 3rd floor Winfried


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2.1 Abstract

Sanification of drinking water by means of electro-chemical activation

L. Jatzwauk, Dresden University Hospital, Dresden, Germany

May 2007

Background: The University Hospital Dresden because of the positioning of the buildings in a pavilion system is using for years several different methods of decontamination of hot water sys-tems. Besides thermal disinfection, the combination of UV rays with ultrasound, filtration at the point of use of drinking water as well as electrolytic process is used.

Methods: In the present case, despite several thermal decontamination, colony counts of Legionella pneumophila were repeatedly on over 1,000 KBE/100ml in the hot water system of the hospital for neurology, building 62. The isolates were to associate to different serogroups, including serogroup 1 with increased virulence. For the intervention in the affected two-story, ten-year old building with 45 beds, a decontamination system based on membrane cell electrolysis (DVGW W229) was installed August 11th, 2006. This system (Hydrostel® WDS) produced from a saline solution by means of electrochemical activation in a membrane electrolysis cell an antimicrobial con-centrate, containing sodium hypochlorite and hypochlorous acid. Composition of the concentrate according to the manufacturer: HOCl (hypochlorous acid) 225 mg / l, O3 (ozone) 0.15 mg / l, H2O2 (hydrogen peroxide) <0.1 mg / l

Results: Within a week of the procedure a significant reduction in colony counts of Legionel-la pneumophila at the water-outlets (defined samples in the showers and sinks on both floors) was achieved, which however appeared increase slightly afterwards. This may be explained by the fact that contaminated biofilm plates were breaking up. However, this contamination disappeared entirely in the course of the experiment by maintaining the concentration of the disinfectant con-stant. After about 8 weeks the detection of Legionella in 100ml of tap water was negative. This condition has remained now unchanged for half a year. Technical problems on the piping were not repor-ted. Patients and staff tolerated the temporary slightly higher chlorine smell. Chemical analysis con-firm the compliance of the water with the drinking water regulation 2001*.

Conclusions: The results show a clear reduction and eradication of microbial contamination of Legionella in the water system after about two months after starting up the unit. * limits of chlorine by german legislation of drinking water: 1.2 mg/L for the injection (exception up to 0.6 mg/L), 0.1 – 0.3 mg/L at the point of use (exception up to 0.6 mg/L)


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2.2 Tables

2.2.1 Table - Samples for Legionella detection, values cfu/100ml, in the building 62, Hospital for

Neurology, University Hospital Dresden, Medical Faculty Carl-Gustav Garus. Period No-vember 2005 to October 2006, starting-up of Hydrostel apparatus 11.08.2006.

2.2.2 Figure - Graphical representation of above shown table.

02.11.05 15.11.05 01.12.05 09.02.06 15.06.06 02.08.06 16.08.06 23.08.06124 Sh before flushing 200 100 10.000 1.000 0 100124 Sh after flushing 600 200 3.300 300 0 0134 Sh before flushing 100 100 200 0 300 0 0 0134 Sh after flushing 800 1100 500 700 1.100 500 0 4134 Si before flushing 1200 100 0 4 0 0 0134 Si after flushing 1400 600 1.500 300 200 0 10061 Si before flushing 100 1.000 300 700 100 10 20061 Si after flushing 1600 300 600 700 200 2 200

30.08.06 06.09.06 13.09.06 20.09.06 27.09.06 11.10.06 18.10.06 25.10.06124 Sh before flushing 300 0 1 0 100 0 0 0124 Sh after flushing 28 0 0 0 400 0 0 0134 Sh before flushing 100 0 0 0 0 0 0 0134 Sh after flushing 100 0 0 0 100 0 0 0134 Si before flushing 400 0 0 0 200 0 0 0134 Si after flushing 400 0 0 0 100 0 0 061 Si before flushing 2.800 1.400 7 0 200 0 0 061 Si after flushing 1.500 100 1 0 400 0 0 0

124 Shower

HYDROSTEL UNIT

INSTALLATION

Sink

124 Shower

Room Place Sample

134Shower

Sink

O61 Sink

134Shower

Sink

O61

124$Sh$before$flushing$

124$Sh$a3er$flushing$

134$$Sh$before$flushing$

134$Sh$a3er$flushing$

134$Si$before$flushing$

134$Si$a3er$flushing$

61$Si$before$flushing$

61$Si$a3er$flushing$

0$

100$

200$

300$

400$

500$

02.11.05$

15.11.05$

01.12.05$

09.02.06$

15.06.06$

02.08.06$

16.08.06$

23.08.06$

30.08.06$

06.09.06$

13.09.06$

20.09.06$

27.09.06$

11.10.06$

18.10.06$

25.10.06$

Building(62(+(Legionella(/100(ml(


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3.1 Abstract

Evaluation of two disinfection systems for Legionella eradication from a hospital water supply

L. Franzin, Amedeo di Savoia Hospital, ASL TO2, Turin, Italy

May 2008

Background: Nosocomial infections are prevented using control measures against Legionel-la proliferation in water distribution system. However complete elimination of the bacteria is difficult to achieve with any disinfection approach. In this study we evaluated th efficacy of two conti-nuous systemic methods to eradicate Legionella from a hospital water supply.

Methods: System 1 is electrochemical activated water containing sodium hypochlorite (neutral ECAS-Anolyte); system 2 is solution of hydrogen peroxide and silver *. These continuous dis-infection systems were installed in a hospital in two ditinct water suplies after hot water tank and before hot water distribution. Seven points of each water system were chosen for the study. Two samplings were performed before systems installation; after didinfection, 8 samplings were periodi-cally performed for 5 months. A total of 70 samples were analysed for each system. Culture was performed following a standard quantitative protocol (detection limit 20 cfu/L). Samples (5L) were concentrated by filtration. Aliquots (0.1 mL) of the untreated, heattreated and acid.washed sus-pensions were plated on BCYE, BMPA and MWY. The plates were incubated at 37°C for 15 days and Legionella colonies typed.

Results: System 1. Samples from water supply 1 showed Legionella contamination of 60-180 cfu/L in hot water tank and of 300-16000 cfu/L in distal points. After starting a continuous disinfec-tion treatment (free chlorine 0.3 – 1.2 mg/L, mean 0.6 mg/L) all samples were negative. System 2. Samples from water supply 2 showed 180-24000 cfu/L. After starting the disinfection, at the level of 2 mg/L of hydrogen peroxide, the contamination was 20-15000 cfu/L; during the obser-vation period the product showed variable concentrations and only in the second-last sampling, with higher concentration of product, the culture was negative. The colonization appeared again in the last sampling up to 600 cfu/L.

Conclusions: System 1 was effective in eradicating Legionella from hospital water supply in this experiment, with free chlorine concentration > 0.2 mg/L (level suggested by italian legislation 0.2 mg/L **). System 2 based on hydrogen peroxide and silver was not efficient at the concentrati-on proposed by manufacturer in this study. For systemic disinfection madalities the disinfectant le-vels must be carefully monitored. * not permitted by german legislation of drinking water for continuous treatment ** limits of chlorine by german legislation of drinking water: 1.2 mg/L for the injection (exception up to 0.6 mg/L), 0.1 – 0.3 mg/L at the point of use (exception up to 0.6 mg/L)


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3.2 Tables

After the six-month research at one of the twelve hot water circuits of the large Hospital of Asti, as documented by the above report, the medical management decided to install the ECAS-Anolyte system on all hot water systems. The works were realized in October-November 2008. The experiences and current samplings were published in November 2009 at a congress of the ISS (Instituto Superiore di Sanita / National Institute of Health ) at Rome by R.Broda, Health Department, Hospital of Asti and F. Migliarina, technical management, Hospital of Asti, entitled "Prevention and control of legionellosis: experiences from the hospi-tal of Asti". Following a brief summary of the results:

3.2.1 Table 1. Amount of Legionella in hot water supply line, hot water return line and on defined points of use in the building in the period October 2008 – June 2009.

HW SUPPLY 27.10.08 22.12.08 23.03.09 22.06.09BOIL 1 100 100 100 100BOIL 2 100 100 100 100BOIL 3 100 100 100 100BOIL 4 100 100 100 100BOIL 5 100 100 100 100BOIL 6 100 100 100 100BOIL 7 100 100 100 100BOIL 8 3200 100 100 100BOIL 9 170000 100 100 100BOIL 10 400 100 100 100BOIL 11.1 700 100 100 100BOIL 11.2 200 100 100 100

HW RETURN 27.10.08 22.12.08 23.03.09 22.06.09BOIL 1 100 100 100 100BOIL 2 100 100 100 100BOIL 3 100 100 100 100BOIL 4 2000 2000 2000 100BOIL 5 4000 89 89 100BOIL 6 4500 4500 100 100BOIL 7 600 100 100 100BOIL 8 3300 100 100 100BOIL 9 200000 100 100 3000BOIL 10 17000 100 100 1000BOIL 11.1 3100 100 100 350BOIL 11.2 1600 130 130 100

0"

2000"

4000"

6000"

8000"

10000"

27.10.08" 22.12.08" 23.03.09" 22.06.09"

ufc/L&

Hot&Water&Supply&

BOIL"1"

BOIL"2"

BOIL"3"

BOIL"4"

BOIL"5"

BOIL"6"

BOIL"7"

BOIL"8"

BOIL"9"

BOIL"10"

BOIL"11.1"

BOIL"11.2" 0"

2000"

4000"

6000"

8000"

10000"

27.10.08" 22.12.08" 23.03.09" 22.06.09"

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BOIL"2"

BOIL"3"

BOIL"4"

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BOIL"6"

BOIL"7"

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BOIL"9"

BOIL"10"

BOIL"11.1"

BOIL"11.2"

0"

10000"

20000"

30000"

40000"

50000"

27/10/2008" 22/12/2008" 23/03/2009" 22/06/2009"

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Sampling&Point2of2use&Hot&Water&Distribu<on&&&&

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Cam."mort."

OSOO4"

OM019"

ONOO2"

3Q037"

40050"

OQ057"

ORO36"

OQ016"

SR025"

0D137"

0B020"

3B054"

4D049"

4F023"

3F030"

1F080"

3P050"

1R065"

4R040"

3R058"


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4.1 Abstract

Impact of a new electro chemical activation system for water disinfection on Legionella pneumophila isola-

tion in hospital potable water systems.

J.M.Rivera, Preventive Medicine Department, School of Medicine, Universidad Complutense, Madrid, Spain

September 2008

Background: Since the discovery in 1985 that hospital-acquired legionnaires’ disease usually arises through the potable water supply, nearly all hospital outbreaks have been linked to potable water, and nosocomial cases linked to cooling water have all-but disappeared. However noso-comial legionellosis can be underestimated because the rapid diagnostic test for Legionella is spe-cific for serogroup 1, not detecting cases produced by serogroups 2-14. In previous studies, Le-gionella pneumophila serogroups 2-14 was responsible for the seasonality observed in Legionella detection in potable water systems with low chlorine levels as predictive parameter of isolation, whereas L. pneumophila serogroup 1 was responsible for the seasonality in Legionella detection in cooling towers where temperature was the predictive parameter of isolation. Since a) hospitals whose water supplies are not colonized by Legionella will not have cases of nosocomial legionello-sis, b) hospital-acquired legionnaires’ disease arises through the potable water supply, c) low chlo-rine levels are associated with high isolation rate in these systems, and d) serogroups 2-14 are re-sponsible for seasonality in isolation rate in these systems, it seems logical to explore new methods increasing chorine levels to prevent future seasonality isolation waves for these serogroups.

Methods: A total of 363 samples were collected from unfiltered taps from potable water sys-tems of Residencia Cantabria (Santander, Spain) from the 1st of January, 2005 to the 30th of Sep-tember, 2008. The water disinfectant apparatus (Hydrostel; Idrovital S.r.l, Empoli, Fi, Italy) was in-stalled on the 23th of September 2007 and consisted in a completely automatic system for the pro-duction of an aqueous solution of NaOCl (sodium hypochlorite) from water and NaCl (99.5% purity) through an electrolysis procedure (Electro Chemical Activation System).

Results: This field single-centre study explores the efficacy of an electro chemical activation system (installed on 23/September/2007) for Legionella disinfection of hospital potable water sys-tems. Samples (n=363) were collected from taps (1/January/2005-30/September/2008): 250 pre-installation and 113 post-installation. Chlorine levels were higher (p<0.001) post-installation (0.55 ± 0.41 versus 1.19 ± 0.44 ppm). A total of 138 (38.0%) samples were positive for L. pneumophila; 111 (80.4%) of them belonging to serogroups 2-14. Post-installation, the isolation rate was significantly lower (46.8% vs. 18.6%; p<0.001, odds ratio= 0.26; 95%CI= 0.15-0.44) due to the significant (p<0.001; odds ratio= 0.25; 95%CI = 0.14-0.45) reduction in L. pneumophila serogroups 2-14 from 38.4% to 13.3%. Mean colony counts were significantly (p<0.001) lower (2.84 log10 cfu versus 3.32 log10 cfu) post-installation. When comparing isolation rates by season, a significant decrease in isolation rates was obtained post-installation in spring (44.4% vs 0.0%; p<0.001), summer (80.0% vs. 25.0%; p=0.003) and autumn (72.0% vs 28.9%; p=0.018), but not in winter (18.5%, vs. 11.8% p=0.688), where the isola-tion rate was lower. The seasonal wave constructed with pre-installation data was significantly de-creased post-installation by decreasing isolation rates in summer and autumn to rates similar to those found in winter pre-installation. The results obtained in this study show the efficacy of the elec-tro chemical activation system in reducing Legionella isolation rates from distal sites (countering its increase in spring, summer and autumn) to a minimum, by significantly increasing chlorine levels.

Conclusions: The present field study evaluates in a single hospital the effect of the imple-mentation of a new automatic method for disinfection of Legionella from the hospital water supply as the main route for hospital-acquired legionellosis nowadays. The new system produced signifi-cant changes post- installation in physico-chemical variables in taps samples, affecting isolation rate and bacterial concentration.


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4.2 Tables

4.2.1 Table - Yearly and seasonal distribution of samples collected, of total positive samples and

of samples positive to L. pneumophila serogroup 1 (S1) and serogroups 2-14 (S2-14).

4.2.2 Figure - Percentage of positive isolates by seasons (winter-W-, spring-SP-, summer-SU- and

autumn-A-) before and after installation (black line) of the electrolytic device.

Winter Spring Summer Autumn Winter Spring Summer AutumnSamples 30 30 20 16 27 27 25 8

S1 0 2 4 4 2 0 1 0S2-14 5 8 12 3 3 12 20 8Total 5 10 16 7 5 12 21 8

Winter Spring Summer Autumn Winter Spring Summer AutumnSamples 23 17 27 35 17 32 12 17

S1 3 6 2 3 1 0 1 1S2-14 8 10 7 9 1 0 2 3S2-14 11 13* 9 12 2 0 3** 4**

* 3 samples yielded L. pneumophila S1 and S2-14.** Samples yielded from POU not more in use and partly detached from main water supply ( no chlorine detection)

2005 2006

2007 2008

scientific fact file legionella contamination in...

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