Persistence of organic residue and viable microbes on gastrointestinal endoscopes despite reprocessing in accordance with guidelinesCori L. Ofstead, MSPH1,2, Pritish K. Tosh, MD2, Hannah L. Yellin, BA,1 Evan M. Doyle, BS1, Catherine K. Rocco, RN, MSN, CNOR1, Todd H. Baron, MD3, Kavel H. Visrodia, MD4, Harry P. Wetzler, MD, MSPH1

1Ofstead & Associates, Inc., Saint Paul, MN; 2Division of Infectious Diseases, Mayo Clinic, Rochester, MN; 3Division of Gastroenterology & Hepatology, University of North Carolina, Chapel Hill, NC; 4Department of Internal Medicine, Mayo Clinic, Rochester, MN

3. Results 4. Conclusions

Citations 1. Alrabaa SF, et al. AJIC. Jun 2013; 41(6): 562-564.

2. Carbonne A, et al. Euro Surveillance. Dec 2010; 15(48):1-6.

3. Kovaleva J, et al. Endoscopy. Oct 2009; 41(10): 913-916

4. Frias M, et al. MMWR. Jan 2014; 62(51): 1051

5. SGNA. Standards of infection control in reprocessing. Gastroenterology Nursing; 2012:1-23.

6. AAMI. Chemical sterilization and high-level disinfection in health care facilities. 2013.

7. Alfa MJ, et al. AJIC. Nov 2012; 40(9):860-865.

8. Visrodia KH, et al. ICHE. Forthcoming 2014.

9. Rutala WA and Weber DJ. Guideline for disinfection and sterilization in healthcare facilities. CDC/HICPAC; 2008.

10. Petersen BT, et al. Multisociety guideline on reprocessing. GIE; Jun 2011;73(6):1075-1084.

100%

75%

50%

25%

0%

Endo

scop

es w

ithm

icro

bial

gro

wth

(%)

Bedside clean(n=13)

Manual clean(n=13)

HLD(n=11)

Storage(n=11)

92%

46%

64%

9%

MICROBIAL GROWTH

Figure 1: Viable microbes recovered from endoscopes after all steps of reprocessing

Note: Results represent findings from sampling after these reprocessing steps

100000

10000

1000

100

10

1

Mea

n AT

P (R

LUs)

Controlhandle

Distalend

Biopsyport

Auxiliarywater port

Suction/biopsychannel

Auxiliarywater channel

5483

31 3777

8741

99

29

233

26964

905

243 162381

25 19 19

4763

273

74 66

8 5 514

Bedside clean Manual clean HLD Storage

200 RLUs

Figure 3: ATP persisted through reprocessing on sampled endoscopes

RLUs (Relative light units); 200 RLUs (Validated benchmark for suction/biopsy channels after manual cleaning)

1. Introduction• Contaminated gastrointestinal (GI) endoscopes can transmit multi-drug

resistant organisms.1-4

• Guidelines state visual inspection is sufficient to verify effectiveness of cleaning.5,6

• Validated* rapid indicator tests can be used to detect organic residue on endoscopes.7,8

• Meticulous cleaning is necessary to remove debris that may interfere with disinfectants.9

• High-level disinfection (HLD) should inactivate microbes (except remnant spores).10

• This study evaluated residual contamination when reprocessing guideline adherence was confirmed via direct observation.

2. Methods• Setting: Large tertiary care GI center Dedicated reprocessing rooms

and technicians• Gastroscopes and colonoscopes: Clinically-used Controls (e.g., brand new)

• Guideline adherence monitored via direct observation

• Measures taken to prevent environmental contamination*

• Samples taken after: Bedside cleaning Manual cleaning HLD Overnight storage

• Multiple components evaluated

• Tests conducted: Visual inspection Aerobic cultures Rapid indicators: ATP Protein Hemoglobin Carbohydrate

DisclosuresThe study was conducted independently by researchers from Ofstead & Associates, Inc. and Mayo Clinic†. The study was supported in part with a research grant from 3M Company, which provided Clean-Trace™ Surface ATP, Clean-Trace™ Water ATP, Clean-Trace™ Surface Protein-High Sensitivity, Petrifilm™ Aerobic Plate Count, and other study materials. The sponsor did not have access to the data nor participate in writing the abstract or the content of this poster.

†Dr. Baron was affiliated with Mayo Clinic at the time of the study. * Additional information about tests, benchmarks, and results provided in a Frequently Asked Questions document available upon request

Case StudyRapid indicators identified persistent contamination on all study endoscopes. Extensive cleaning and disinfection measures were employed for one gastroscope (Figure 4).• Measures: Three rounds of manual cleaning Cleaning and HLD in a fully-automated

reprocessor Overnight soaking in enzymatic detergent Second round of HLD

• Contamination persisted on various components through multiple rounds of reprocessing:

Viable microbes (2 rounds) Protein (5 rounds) ATP >200 RLUs (all 6 rounds)

100000

10000

1000

100

10

1

ATP

(RLU

s)

Controlhandle

Distalend

Biopsyport

Suction/biopsychannel

646

5027 21 16 22

2792

223102

4126

126

14389

514315 439

100

307

2576

298 264110

311

42

Bedside clean Manual clean 1 Manual clean 2 Manual clean 3 Auto C & HLD Soaking & HLD

200 RLUs

Positivefor protein

Positive for microbial growth

Figure 4: Contamination persisted on one gastroscope despite extensive measures

Auto C & HLD (Cycle in an automated endoscope reprocessor that performs both cleaning and HLD); Soaking & HLD (Overnight soaking in enzymatic detergent followed by HLD)

100%

75%

50%

25%

0%

Cont

rol h

andl

es w

ithpr

otei

n re

sidu

e (%

)

Bedside clean(n=13)

Manual clean(n=12)

HLD(n=11)

Storage(n=9)

PROTEIN RESIDUE92%

75%

55%

78%

Figure 2: Protein persisted on control handles through all steps of reprocessing

• Residual endoscope contamination: Not reliably identified via visual inspection Detected by multiple tests Remained on multiple components Persisted despite guideline adherence Not eliminated by extensive reprocessing methods

• Viable microbes survived high-level disinfection

• Recommendations: Re-evaluate current endoscope reprocessing guidelines Conduct surveillance to ensure microbes are eliminated Use a routine rapid monitoring system to verify cleaning

Contamination persisted through reprocessing.

• 15 endoscopes sampled during 60 encounters:

Visual inspection of endoscopes (60) and sampling materials (496)

Aerobic cultures on 88 channel effluent samples (352 plates)

Rapid indicator tests on 438 components

• After manual cleaning, visible residue was: Not seen on endoscopes Observed on swabs or in effluent (31%)

• Cultures of channel effluent showed (Figure 1 and Table 1): No growth from controls Frequent growth after bedside cleaning Viable microbes present after HLD• Rapid indicators showed: Hemoglobin only after bedside cleaning (38%) Protein not eliminated by reprocessing (Figure 2) ATP levels commonly exceeded post-cleaning benchmark (Figures 3 and 4)

Extensive measures did not eliminate contamination (Figure 4)

Table 1: Bacteria identified in aerobic cultures of channel effluent

Organisms recoveredSteps of reprocessing

Bedside cleaning Manual cleaning HLD Storage

Bacillus

cereus/thuringiensis/mycoides 6

circulans 6

Escherichia coli 6

Enterococcus

casseliflavus 6

faecalis 6

gallinarum 6

Micrococcus luteus 6 6 6

Rhizobium radiobacter 6

Sphingomonas paucimobilis 6 6

Staphylococcus

epidermidis 6 6

hominis ssp hominis 6

warneri 6 6

Streptococcus

gordonii 6

haemolyticus 6

mitis/oralis 6

mitis/oralis/cristatus 6

ovis/parasanguinis/sanguinis 6

parasanguinis 6

pluranimalium 6

pluranimalium/Granulicatella adiacens 6

salivarius 6

vestibularis 6

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