Endoscope disinfection and its pitfalls--requirement for retrograde surveillance cultures
A J Buss1, M H Been, R P Borgers
1Department of Medical Microbiology, University Medical Centre Groningen, Groningen, The Netherlands. a.j.buss@mmb.umcg.nl
Background And Study Aims:
Several endoscopy-related outbreaks of infection have been reported in recent years. For early recognition of inadequate disinfection of endoscopes we designed a microbiological surveillance system to evaluate the efficacy of the cleaning and disinfection procedure, and to trace disinfection problems to individual endoscopes or washer-disinfectors.
Methods:
Our surveillance protocol included anterograde and retrograde sampling, a decision algorithm, genetic fingerprinting, and scanning electron microscopy.
Results:
Over a period of 29 months we found an increasing number of patient-ready endoscopes testing positive for Candida species other than albicans, especially C. parapsilosis. These yeasts were also isolated from the washer-disinfectors. The number of positive tests for Candida species varied from 1 out of 21 to 14 out of 27 samples from nine frequently used endoscopes. The number of colony-forming units per milliliter ranged from 1 - 10 to 3000 for endoscopes and 0.002 to 0.06 for the washer disinfectors. DNA fingerprinting was not able to discriminate different strains within C. parapsilosis.
Conclusions:
Our protocol was able to detect a structural problem in the endoscope disinfection process. Retrograde sampling was crucial for this purpose, because it has much higher sensitivity than anterograde sampling. Endoscopes with damaged working channels are probably the source of the contamination problem with Candida species.
Insights
A new microbiological surveillance system detected Candida species contamination on endoscopes and washer-disinfectors. Damaged endoscope channels were identified as the likely source of recurring disinfection failures.
Area of Science:
- Infection control in healthcare settings
- Microbiology of medical devices
Background:
- Endoscope-related infections pose a significant risk.
- Previous outbreaks highlight the need for effective disinfection monitoring.
Purpose of the Study:
- To develop and evaluate a microbiological surveillance system for endoscope disinfection.
- To identify sources of contamination in the cleaning and disinfection process.
Main Methods:
- Utilized anterograde and retrograde sampling techniques.
- Implemented a decision algorithm and genetic fingerprinting.
- Employed scanning electron microscopy for detailed analysis.
Main Results:
- Detected increasing contamination of patient-ready endoscopes with non-albicans Candida species, particularly C. parapsilosis.
- Candida species were also isolated from washer-disinfectors.
- Retrograde sampling demonstrated higher sensitivity in detecting contamination.
Conclusions:
- The developed surveillance protocol effectively identified a structural issue in endoscope disinfection.
- Damaged working channels in endoscopes are implicated as the primary source of Candida contamination.
- Retrograde sampling is a critical method for sensitive detection of endoscope contamination.
Related Concept Videos
01:26Urine Studies II: Urine Culture and Sensitivity Test
01:28Endoscopic Procedures III: Video Capsule Endoscopy
01:26Endoscopic Procedures IV: Sigmoidoscopy and Laproscopy
Sigmoidoscopy
Sigmoidoscopy is a diagnostic procedure that uses a flexible sigmoidoscope equipped with a light source and camera to examine the rectum and sigmoid colon. The procedure involves inserting the tube through the anus...
01:25Endoscopic Procedures II: Colonoscopy
01:29Need for Obtaining Pure Cultures
01:29Endoscopic Procedures I: Esophagogastroduodenoscopy
During an EGD, the endoscope can be used to: