Prospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Endosc. Jan 16, 2018; 10(1): 51-55
Published online Jan 16, 2018. doi: 10.4253/wjge.v10.i1.51
Bacterial presence on flexible endoscopes vs time since disinfection
Katlin I Mallette, Peter Pieroni, Sonny S Dhalla
Katlin I Mallette, Sonny S Dhalla, Max Rady College of Medicine, University of Manitoba, Winnipeg, Manitoba R3E 3P5, Canada
Peter Pieroni, Diagnostic Services of Manitoba, Westman Laboratory, Department of Microbiology, Brandon Regional Health Centre, Brandon, Manitoba R7A 7H8, Canada
Sonny S Dhalla, Gastrointestinal Endoscopy Unit, Brandon Regional Health Centre, Brandon, Manitoba R7A 2B3, Canada
Author contributions: Mallette KI, Pieroni P and Dhalla SS participated in the design of the research and collection of data; Mallette KI conducted the data analysis and drafted the manuscript; Pieroni P and Dhalla SS assisted with the drafting of the manuscript; all authors read and approved the final manuscript.
Institutional review board statement: This study was reviewed and approved by the Gastrointestinal Endoscopy department administration at Brandon Regional Health Centre.
Informed consent statement: All patients provided written consent prior to the performed procedure; all data was anonymized prior to analysis.
Conflict-of-interest statement: Sonny S Dhalla is a member of the World Journal of Gastrointestinal Endoscopy Editorial Board. Katlin I Mallette and Peter Pieroni have no conflicts of interest to declare.
Data sharing statement: Complete dataset is available from the first author by e-mail at mallett4@myumanitoba.ca. No additional data is available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Sonny S Dhalla, MD, FRCSC, FACS, Gastrointestinal Endoscopy Unit, Brandon Regional Health Centre, 339 Princess Avenue, Brandon, Manitoba R7A 2B3, Canada. varsity@wcgwave.ca
Telephone: +1-204-7293727 Fax: +1-204-7289535
Received: July 10, 2017
Peer-review started: July 18, 2017
First decision: September 7, 2017
Revised: October 22, 2017
Accepted: November 10, 2017
Article in press: November 10, 2017
Published online: January 16, 2018
Processing time: 182 Days and 4 Hours
Abstract
AIM

To correlate the length of endoscope hang time and number of bacteria cultured prior to use.

METHODS

Prospectively, we cultured specimens from 19 gastroscopes, 24 colonoscopes and 5 side viewing duodenoscopes during the period of 2011 to 2015. A total of 164 results had complete data denoting date of cleansing, number of days stored and culture results. All scopes underwent initial cleaning in the endoscopy suite utilizing tap water, and then manually cleaned and flushed. High level disinfection was achieved with a Medivator© DSD (Medivator Inc., United States) automated endoscope reprocessor following manufacturer instructions, with Glutacide® (Pharmax Limited, Canada), a 2% glutaraldehyde solution. After disinfection, all scopes were stored in dust free, unfiltered commercial cabinets for up to 7 d. Prior to use, all scopes were sampled and plated on sheep blood agar for 48 h; the colony count was obtained from each plate. The length of endoscope hang time and bacterial load was analyzed utilizing unpaired t-tests. The overall percentage of positive and negative cultures for each type of endoscope was also calculated.

RESULTS

All culture results were within the acceptable range (less than 200 cfu/mL). One colonoscope cultured 80 cfu/mL after hanging for 1 d, which was the highest count. ERCP scopes cultured at most 10 cfu, this occurred after 2 and 7 d, and gastroscopes cultured 50 cfu/mL at most, at 1 d. Most cultures were negative for growth, irrespective of the length of hang time. Furthermore, all scopes, with the exception of one colonoscope which had two positive cultures (each of 10 cfu/mL), had at most one positive culture. There was no significant difference in the number of bacteria cultured after 1 d compared to 7 d when all scopes were combined (day 2: P = 0.515; day 3: P = identical; day 4: P = 0.071; day 5: P = 0.470; day 6: P = 0.584; day 7: P = 0.575). There was also no significant difference in the number of bacteria cultured after 1 day compared to 7 d for gastroscopes (day 2: P = 0.895; day 3: P = identical; day 4: P = identical; day 5: P = 0.893; day 6: P = identical; day 7: P = 0.756), colonoscopes (day 2: P = 0.489; day 4: P = 0.493; day 5: P = 0.324; day 6: P = 0.526; day 7: P = identical), or ERCP scopes (day 2: P = identical; day 7: P = 0.685).

CONCLUSION

There is no correlation between hang time and bacterial load. Endoscopes do not need to be reprocessed if reused within a period of 7 d.

Keywords: Bacteria; Endoscopy; Processing; Hang time; Colonoscopy; Endoscopic retrograde cholangiopancreatography; Gastroscopy

Core tip: Several cases of transmission of antibiotic resistant microbes have recently been reported, most notably carbapenem-resistant Enterobacteriaceae. However, according to our research, there does not appear to be a correlation between the number of days that an endoscope has been hanging and the bacterial load. Therefore, reprocessing of endoscopes is unnecessary prior to use, if they undergo cleaning according to guidelines, maintained in a ventilated, dust-free cabinet between use and the period of hang time does not exceed 7 d.