Related Experiment Video
Updated: Apr 6, 2026
Flexible Colonoscopy in Mice to Evaluate the Severity of Colitis and Colorectal Tumors Using a Validated Endoscopic Scoring System
Published on: October 16, 2013
Persistent contamination on colonoscopes and gastroscopes detected by biologic cultures and rapid indicators despite
Cori L Ofstead1, Harry P Wetzler2, Evan M Doyle2
1Ofstead & Associates, Saint Paul, MN; Division of Infectious Diseases, Mayo Clinic, Rochester, MN.
Background:
Pathogens have been transmitted via flexible endoscopes that were reportedly reprocessed in accordance with guidelines.
Methods:
Researchers observed reprocessing activities to ensure guideline compliance in a large gastrointestinal endoscopy unit. Contamination was assessed immediately after bedside cleaning, manual cleaning, high-level disinfection, and overnight storage via visual inspection, aerobic cultures, and tests for adenosine triphosphate (ATP), protein, carbohydrate, and hemoglobin.
Results:
All colonoscopes and gastroscopes were reprocessed in accordance with guidelines during the study. Researchers collected and tested samples during 60 encounters with 15 endoscopes. Viable microbes were recovered from bedside-cleaned (92%), manually cleaned (46%), high-level disinfected (64%), and stored (9%) endoscopes. Rapid indicator tests detected contamination (protein, carbohydrate, hemoglobin, or ATP) above benchmarks on bedside-cleaned (100%), manually cleaned (92%), high-level disinfected (73%), and stored (82%) endoscopes. Visible residue was never observed on endoscopes, but it was often seen on materials used to sample endoscopes. Seven endoscopes underwent additional reprocessing in response to positive rapid indicators. Control endoscope channels were free of biologic residue and viable microbes.
Conclusion:
Despite reprocessing in accordance with US guidelines, viable microbes and biologic debris persisted on clinically used gastrointestinal endoscopes, suggesting current reprocessing guidelines are not sufficient to ensure successful decontamination.
Insights
Despite following reprocessing guidelines, flexible endoscopes remained contaminated with viable microbes and biologic debris. Current reprocessing protocols may be insufficient for complete decontamination, posing infection risks.
Area of Science:
- Infection Control
- Gastroenterology
- Medical Device Reprocessing
Background:
- Flexible endoscopes have been implicated in pathogen transmission, even when reprocessing guidelines were reportedly followed.
- Ensuring effective reprocessing of gastrointestinal endoscopes is critical for patient safety.
Purpose of the Study:
- To assess the effectiveness of current US reprocessing guidelines for flexible gastrointestinal endoscopes.
- To identify residual contamination on endoscopes after various reprocessing steps.
Main Methods:
- Researchers observed reprocessing activities in a large endoscopy unit to ensure guideline compliance.
- Contamination was assessed using visual inspection, aerobic cultures, and rapid indicator tests (ATP, protein, carbohydrate, hemoglobin) after bedside cleaning, manual cleaning, high-level disinfection, and storage.
Main Results:
- Viable microbes were recovered from endoscopes after bedside cleaning (92%), manual cleaning (46%), high-level disinfection (64%), and storage (9%).
- Rapid indicator tests detected significant contamination above benchmarks on endoscopes after bedside cleaning (100%), manual cleaning (92%), high-level disinfection (73%), and storage (82%).
- Visible residue was not observed on endoscopes, but was present on sampling materials, indicating unseen contamination.
Conclusions:
- Current US reprocessing guidelines for flexible gastrointestinal endoscopes are insufficient to ensure complete decontamination.
- Viable microbes and biologic debris persist on endoscopes even when guidelines are followed, highlighting a need for improved reprocessing strategies.
Related Concept Videos
01:30Cleaning, Sterilization, and Disinfection
Cleaning
The cleaning process usually involves using water with detergents or enzymatic cleaner and removing foreign material from objects and surfaces, including organic material such as body fluids or inorganic material like soil. Cleaning is performed before high-level disinfection and sterilization because foreign materials on the cover of the devices interfere with process...
01:17Transmission-based Precautions I: Contact, Enteric, and Droplets
Contact Precautions:
Contact precautions are the measures taken to prevent the transmission of infectious agents, especially epidemiologically important microorganisms such as MRSA or influenza, primarily transmitted through direct or indirect contact with an...
01:25Endoscopic Procedures II: Colonoscopy
01:26Standard Precaution
Hand hygiene is the most crucial means to prevent the transmission of disease. Employers are legally required to provide their workers with personal protective equipment (PPE) to minimize exposure or contact with...
01:30Methods of Sterilization II: Chemical Methods
Using chemical sterilization rather than heat to clean out equipment is recommended. It eradicates and removes all bacteria,...
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...