Bactiquant Water Rapid Onsite Screening for Assessing Legionella Risk
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Bactiquant Water Rapid Onsite Screening for Assessing Legionella Risk Presented by Lisa Rogers
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Bactiquant Water Rapid Onsite Screening for Assessing Legionella Risk. Presented by Lisa Rogers. - PowerPoint PPT Presentation
Transcript of Bactiquant Water Rapid Onsite Screening for Assessing Legionella Risk
Bactiquant Water Rapid Onsite Screening
for Assessing Legionella Risk
Presented by Lisa Rogers
“Legionellosis emerged because of human alteration of the environment, since Legionella species are found in aquatic environments, and thrive in warm water and warm, damp places, such as cooling towers”
Legionella and the prevention of legionellosis, WHO 2007
World Wide• Since 1976, 35 outbreaks reported 2-800 cases
– 11 in NA (US/CA)– 14 in AUS/NZ– 10 in Europe
• Sources – 13 Cooling towers– 5 each, Spas/hot tub, DHW, AC, and 4 unknowns– Misc include potting mix, fountain, industrial systems
Year City Location Cause Cases Fatality rate
2012 Québec City, Canada Lower Québec City Possibly cooling towers 180 7 %
2012 Calp, Spain AR Diamante Beach Hotel Possibly solar water heating system for spa and DHW 18 17%
2012 Scotland SW of Edinburgh Possibly cooling towers 99 3%
2012 Chicago,Illinois JW Marriott Hotel Decorative Lobby Fountain 10 30%
2012 Auckland, NZ Unknown Water Source and/or AC 11 9%
2012 Stoke-on-Trent, UK Warehouse, Fenton Hot tub 19 5%
2012 Pittsburgh, PA VA Hospital unknown 22 27%
2013 Queensland, AUS Wesley Hospital NYD, probably hot water system. 2 50%
2013 Memphis,TN 24-Hour Fitness NYD probably pool or spa. 3 0%
2013 Milwaukee,WI Not yet determined Not yet determined, ongoing 20
2013 Reynoldsburg, OH Wesley Ridge Retirement Comm Potable water system, ongoing 44
2013 Warstein,Germany Warsteiner Brewery Air conditioning, ongoing 165
2013 Florence, AL Glenwood Nursing Home Unknown, still under investigation. 13
Concerns• CDC estimates 8,000 to 18,000 people are hospitalized
each year in the U.S. Mortality rate is approximately 15%• Legionella bacteria are found naturally in the environment• French study found that L. pneumophila can travel
airborne at least 6 km from its source• Norway study found high velocity, large drift & high
humidity in air scrubber… spread probably for >10 km• WHO estimates the cost savings to implement preventive
plans is $1-3M USD per life saved. (1200 x 1M= $1.2B)
Ideal Water Conditions• Temperatures between 20° and 50°C (68° - 122°F)• Optimal growth range is stagnant water 35° - 46°C [95° - 115°F]• pH between 5.0 and 8.5• Available iron and copper • Sediment/scaling promote growth of commensal microflora• Other micro-organisms including algae, flavobacteria,
and Pseudomonas, which supply essential nutrients for growth of Legionella or harbor the organism (amoebae, protozoa)
• Low biocide concentrations
Water Sampling GuidelinesTable III:7-1. COLONY FORMING UNITS (CFU) OF LEGIONELLA PER MILLILITER
Action Cooling Tower Domestic Water Humidifier
1 100 10 1
2 1,000 100 10
Action 1: Prompt cleaning and/or biocide treatment of the system.Action 2: Immediate cleaning and/or biocide treatment. Take prompt steps to prevent employee exposure.
Source : OSHA, 1999
CDC recently testified that there is no safe level !
Current Sampling StrategyCulture Plate Analysis • 3-5 days for HPC• 7-10 days for Legionella• Planktonic, highly variable, overloading,
background interferences PCR • fast but expensive
How BQW can helpRapid test can be performed in 15-30 mins Easy Sampling and Analysis
EPA ETV verified methodology
+
Bacteria-enzyme
Enzyme substrate Fluorescent compound released
Principle Method
Why is Bactiquant Technology interesting ?
• Culture-independent technique• Quantification of a naturally occuring hydrolase enzyme activity
present in bacteria• High specificity to bacteria, little background interference• Use of fluorescence technology = high sensitivity• Concentration Step = increased sensitivity and significant reduction
in detection time
Laboratory Comparison BQW
1
10
100
1000
10000
100000
1000000
10000000
1 10 100 1000 10000 100000 1000000
BactiQuant analysis result (fu/ml)
HP
C -
DS
6222
(cfu
/ml)
EPA ETV Report Excerpt Table 2: Linearity: BQ Value vs Concentration
Test Organism
Concentration Range
(CFU/mL)
Range of Average BQ
valuesSlope Y-
intercept
Coefficient of Determination
(R2)
Lake Water Indigenous
Bacteria
3.7 x 102 to 6.0 x 103
1542 to 15607 2.38 2243 0.9138
Lake Water Indigenous Bacteria -
without 1:5 dilution
3.7 x 102 to 3.0 x 103
1542 to 11106 3.55 739 0.9689
P. aeruginosa ATCC 27853
8.7 x 102 to 8.0 x 103 868 to 7655 0.95 -136 0.9923
Source Battelle / US EPA -2011
EPA ETV Study Excerpt
High reproducibility
Source Battelle / US EPA -2011
Test IterationAdjusted Fluorescence (fu)
8.0 x 103 CFU/mL
4.7 x 103
CFU/mL2.1 x 103 CFU/mL
8.7 x 102
CFU/mL
1 11392 6128 2799 1249
2 12332 6074 2710 1247
3 11376 6012 2559 1297
4 11513 6508 2768 1437
5 11614 6256 2945 1375
Average 11645 6196 2756 1321
Standard deviation 396 196 140 83
RSD (%) 3.4 3.2 5.1 6.3
EPA ETV Report Excerpt
Test Iteration
BQV Fluorescence (flu)Indigenous Bacteria from Lake
Water(3.7 x 102 CFU/mL)
P. aeruginosa ATCC 27853(4.7 x 103 CFU/mL)
Analyst 1 Analyst 2 Analyst 1 Analyst 2
Average 2363 2225 6888 6691
Standard deviation 152 57 333 93
RSD (%) 6.4 2.6 4.8 1.4
RPD (%) 6.0 2.9
Table 3. Bactiquant®-test Repeatability and Inter-Assay Reproducibility
Table 3 summarizes the repeatability and inter-assay reproducibility results for Bactiquant®-test using two bacterial cultures in water. Two different people analyzed 4 samples of each culture, using different fluorometers.
CASE STUDIES
Critical care facility, Courtesy of Clinical Microbiology Institute, Viborg Hospital, Denmark 2006.
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63 65 67 690
1
2
3
4
5
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7
BQ
Legionella pneumophila serotype 2-14
X-axis Sample No. (1-70)Y-axis Log10(adjusted fluorescence) and Log10(cfu) Legionella pneumophila serotype 2-14
BQ value 10
BQ value 100
BQ value 1000
Australia Case Study• Wesley Hospital, Queensland: 2 cases, 1 death• 5 Building, 560 bed facility• Heat Treatment for 2 weeks @ 70C ( 158F)• Over 3000 samples collected BQ, Legionella,
HPC• 13 days to reopen, 29 days fully operational• BQ used to screen, verify cleaning efficacy and
validate post treatment
104 110 114 135 226 226 Dirty
237A 237B 285 315 316 609 L6 Endo Int 2
0
500
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4000
4500
Comparison between Pre-Treatment (Blue), and Post Treatement samples collected on the 26/9 (Red) and the 30/9 (Green)
Pre-TreatementPost Treatement (26/9)Post Treatement (30/9)
Room Number
BQ H
eter
otro
phic
Micr
obia
l Equ
ival
ent
(cfu
/mL)
9/25/2013 11:00
9/26/2013 12:00
9/26/2013 13:00
9/26/2013 14:30
9/26/2013 16:00
9/26/2013 17:00
9/26/2013 18:30
9/30/2013 12:00
9/30/2013 13:30
9/30/2013 14:30
9/30/2013 16:30
9/30/2013 18:00
0
200
400
600
800
1000
1200
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Mains water 1
Mains water 2
Sample
BQ E
quiv
alen
t cfu
/ml
Excerpt from: The Australian Hospital Engineer, September 2013
“CETEC made use of the Bactiquant® water technology for the rapid screening of total bacterial loading within the potable water network. This technology allowed CETEC in under an hour to obtain results superior to plate count for the network. The ability to obtain rapid results as compared to 4 to 10 day timeframe for conventional
methods presented significant time, logistical and financial savings.”
New Studies The Danish Health Institute has started a two year project now with multiple sites looking at pre-screening as well as post treatment efficacy. Hopefully, some results from that study will be forthcoming later this year.
Pros and Cons
• Rapid onsite testing aids in identifying hotspots• Validate the efficacy of cleaning methods• Monitor for changes in system quickly• HPC nor BQW a perfect predictor of Legionella• Not a substitute for direct Legionella analysis
THANK YOU FOR LISTENING!
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