Multisociety guideline on reprocessing flexible gastrointestinal endoscopes: 2011

Tolerance of Pseudomonas aeruginosa in in-vitro biofilms to high-level peracetic acid disinfection

BACKGROUND

Biofilm has been suggested as a cause of disinfection failures in flexible endoscopes where no lapses in the decontamination procedure can be identified. To test this theory, the activity of peracetic acid, one of the widely used disinfectants in the reprocessing of flexible endoscopes, was evaluated against both planktonic and sessile communities of Pseudomonas aeruginosa.

AIM

To investigate the ability of P. aeruginosa biofilm to survive high-level peracetic acid disinfection.

METHOD

The susceptibility of planktonic cells of P. aeruginosa and biofilms aged 24, 48, 96, and 192 h to peracetic acid was evaluated by estimating their viability using resazurin viability and plate count methods. The biomass of the P. aeruginosa biofilms was also quantified using Crystal Violet assay. Planktonic cells of P. aeruginosa were treated with 5-30 ppm concentration of peracetic acid in the presence of 3.0 g/L of bovine serum albumin (BSA) for 5 min. Biofilms of P. aeruginosa were also treated with various peracetic acid concentrations (100-3000 ppm) for 5 min.

FINDINGS

Planktonic cells of P. aeruginosa were eradicated by 20 ppm of peracetic acid, whereas biofilms showed an age-dependent tolerance to peracetic acid, and 96 h biofilm was only eradicated at peracetic acid concentration of 2500 ppm.

CONCLUSION

Ninety-six-hour P. aeruginosa biofilm survives 5 min treatment with 2000 ppm of peracetic acid, which is the working concentration used in some endoscope washer-disinfectors. This implies that disinfection failure of flexible endoscopes might occur when biofilms build up in the lumens of endoscopes.

Surveillance of Endoscopes: Comparison of Different Sampling Techniques

OBJECTIVE To compare different techniques of endoscope sampling to assess residual bacterial contamination. DESIGN Diagnostic study. SETTING The endoscopy unit of an 1,100-bed university hospital performing ~13,000 endoscopic procedures annually. METHODS In total, 4 sampling techniques, combining flushing fluid with or without a commercial endoscope brush, were compared in an endoscope model. Based on these results, sterile physiological saline flushing with or without PULL THRU brush was selected for evaluation on 40 flexible endoscopes by adenosine triphosphate (ATP) measurement and bacterial culture. Acceptance criteria from the French National guideline (<25 colony-forming units [CFU] per endoscope and absence of indicator microorganisms) were used as part of the evaluation. RESULTS On biofilm-coated PTFE tubes, physiological saline in combination with a PULL THRU brush generated higher mean ATP values (2,579 relative light units [RLU]) compared with saline alone (1,436 RLU; P=.047). In the endoscope samples, culture yield using saline plus the PULL THRU (mean, 43 CFU; range, 1-400 CFU) was significantly higher than that of saline alone (mean, 17 CFU; range, 0-500 CFU; P<.001). In samples obtained using the saline+PULL THRU brush method, ATP values of samples classified as unacceptable were significantly higher than those of samples classified as acceptable (P=.001). CONCLUSION Physiological saline flushing combined with PULL THRU brush to sample endoscopes generated higher ATP values and increased the yield of microbial surveillance culture. Consequently, the acceptance rate of endoscopes based on a defined CFU limit was significantly lower when the saline+PULL THRU method was used instead of saline alone. Infect Control Hosp Epidemiol 2017;38:1062-1069.

Advances in Endoscope Reprocessing Technology and Its Impact on Pathogen Transmission

Pathogen transmissions via flexible endoscopes have been documented in the literature and have been historically related to human error or omission of steps in the reprocessing cycle. The 2008 Centers for Disease Control and Prevention report challenged manufacturers of automated endoscope reprocessors to improve and advance technology to automate more of the reprocessing steps. A review and synthesis of the literature following the 2008 Centers for Disease Control and Prevention report was performed to evaluate whether advances in reprocessing technology have occurred and whether these have had an impact on pathogen transmission via flexible endoscopes. The Iowa Model of Evidence-Based Practice to Promote Quality Care was used to guide the project. The literature search regarding pathogen transmission related to flexible endoscopes yielded 10 documents citing infections from 2008 to 2015. A total of 353 patients were identified as having been infected with a contaminated gastroscope, bronchoscope, or duodenoscope. An evaluation of reprocessing technology identified 3 automated endoscope reprocessors with enhanced capabilities and flushing devices intended to automate portions of the manual cleaning step.

Duodenoscope hang time does not correlate with risk of bacterial contamination

BACKGROUND

Current professional guidelines recommend a maximum hang time for reprocessed duodenoscopes of 5-14 days. We sought to study the association between hang time and risk of duodenoscope contamination.

METHODS

We analyzed cultures of the elevator mechanism and working channel collected in a highly standardized fashion just before duodenoscope use. Hang time was calculated as the time from reprocessing to duodenoscope sampling. The relationship between hang time and duodenoscope contamination was estimated using a calculated correlation coefficient between hang time in days and degree of contamination on the elevator mechanism and working channel.

RESULTS

The 18 study duodenoscopes were cultured 531 times, including 465 (87.6%) in the analysis dataset. Hang time ranged from 0.07-39.93 days, including 34 (7.3%) with hang time ≥7.00 days. Twelve cultures (2.6%) demonstrated elevator mechanism and/or working channel contamination. The correlation coefficients for hang time and degree of duodenoscope contamination were very small and not statistically significant (-0.0090 [P = .85] for elevator mechanism and -0.0002 [P = 1.00] for working channel). Odds ratios for hang time (dichotomized at ≥7.00 days) and elevator mechanism and/or working channel contamination were not significant.

CONCLUSIONS

We did not find a significant association between hang time and risk of duodenoscope contamination. Future guidelines should consider a recommendation of no limit for hang time.

Guideline Implementation: Processing Flexible Endoscopes

The updated AORN "Guideline for processing flexible endoscopes" provides guidance to perioperative, endoscopy, and sterile processing personnel for processing all types of reusable flexible endoscopes and accessories in all procedural settings. This article focuses on key points of the guideline to help perioperative personnel safely and effectively process flexible endoscopes to prevent infection transmission. The key points address verification of manual cleaning, mechanical cleaning and processing, storage in a drying cabinet, determination of maximum storage time before reprocessing is needed, and considerations for implementing a microbiologic surveillance program. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

Korean Society of Gastrointestinal Endoscopy Guidelines for Endoscope Reprocessing

The Korean Society of Gastrointestinal Endoscopy (KSGE) issued guidelines for endoscope reprocessing for the first time in 1995, and the version of the guidelines was updated in August 2009, August 2012, and March 2015. Guidelines for endoscope reprocessing should be revised continuously, because new disinfectants and devices are developed and introduced. The current official version of the KSGE guidelines for endoscope reprocessing is explained herein to assist the reader in understanding the KSGE requirements for cleaning and disinfecting endoscopes.

Clinical Issues- March 2017

Using one flexible endoscope for an upper and lower gastrointestinal (GI) endoscopy procedure Key words: flexible endoscope, esophagogastroduodenoscopy, colonoscopy, enteroscope, risk assessment. Enhanced methods for processing flexible duodenoscopes Key words: flexible duodenoscopes, liquid chemical sterilization, ethylene oxide sterilization, low-temperature sterilization, risk assessment. Modification of the Spaulding classification Key words: Spaulding classification, critical items, semicritical items, mucous membranes, risk assessment. Flushing flexible endoscope lumens with alcohol Key words: flexible endoscopes, isopropyl alcohol, ethyl alcohol, fixative, risk assessment. Using chlorine dioxide wipes for nonchanneled flexible endoscopes Key words: nonchanneled flexible endoscopes, high-level disinfectant, chlorine dioxide, risk assessment.

Risk of infection transmission in curvilinear array echoendoscopes: results of a prospective reprocessing and culture registry

BACKGROUND AND AIMS

The complex design of the elevator mechanism in duodenoscopes has been recognized as a challenge for disinfection and recently implicated as a potential source of persistent bacterial contamination. Curvilinear array (CLA) echoendoscopes also have an elevator mechanism; however, there are no recommendations or data regarding the risk of persistent bacterial contamination of echoendoscopes. Here we hoped to determine the yield of microbial growth with routine bacterial surveillance cultures of reprocessed CLA echoendoscopes.

METHODS

Beginning in February 2015 to February 2016, CLA echoendoscopes at a single tertiary care center underwent prospective bacterial surveillance cultures after reprocessing. Any growth of gram-negative bacilli was considered to be critical. Echoendoscopes with a positive result underwent quarantine followed by repeat disinfection and culture.

RESULTS

During the study period, 540 cultures were obtained; 521 (96.5%) were primary cultures obtained from 18 CLA echoendoscopes. Twenty-two primary cultures (4.2%) were positive for gram-negative bacilli after high-level disinfection reprocessing. Eleven different bacteria were isolated: Klebsiella pneumoniae, Citrobacter freundii, Escherichia coli, Pseudomonas aeruginosa, Klebsiella oxytoca, Sphingomonas paucimobilis, Acinetobacter baumanii, Enterobacter cloacae, Hafnia alvei, Pseudomonas putida, and Stenotrophomonas maltophilia. Antibiotic sensitivity data on 19 of 24 bacteria (79.2%) isolated from positive primary cultures revealed no documented cases of carbapenem-resistant enterobacteriaceae, cephalosporin-resistant-Klebsiella, or multidrug-resistant Acinetobacter. There have been no documented cases of patient-to-patient transmission.

CONCLUSIONS

After following standard high-level disinfection and reprocessing, CLA echoendoscopes can remain culture positive for high-concern organisms. Recommendations regarding infection risk should take into consideration elevator-containing echoendoscopes in addition to duodenoscopes to ensure patient safety and endoscope reprocessing efficacy.

Prospective microbiologic evaluation of the forceps elevator in closed-channel duodenoscopes after reprocessing

BACKGROUND

Endoscopes are well-known sources of bacterial transmission in health care facilities offering endoscopy services. The association between multidrug-resistant bacterial infections in patients who had undergone an endoscopic retrograde cholangiopancreatography procedure with reprocessed duodenoscopes has been much discussed. Bacterial contamination of duodenoscopes has been attributed to difficulties with reprocessing these devices, specifically the distal end of the scope, which features a movable forceps elevator. In light of a recent Food and Drug Administration warning letter to Olympus regarding their closed-channel duodenoscope model TJF-Q180V, the aim of our study was to prospectively evaluate the efficacy and safety of our current reprocessing procedures with regard to the TJF-Q180V duodenoscope models used in our hospital.

METHODS

From August 2015-March 2016, we prospectively collected microbiologic surveillance samples from 6 TJF-Q180V model duodenoscopes in routine use at the Division of Gastroenterology and Hepatology using the ESwab collection system (COPAN Diagnostics Inc, Murrieta, CA).

RESULTS

A total of 237 microbiologic samples from the forceps elevator were obtained during the survey period. None of the samples yielded microorganism growth.

CONCLUSION

These findings suggest that when following a diligent and validated reprocessing standard in accordance with manufacturer's recommendations, closed-channel endoscope models can still be used. Nevertheless, validated adaptions of current closed-channel duodenoscope models are needed to allow for simple and safe reprocessing. Furthermore, comprehensive postmarket surveillance needs to be established.

Multidepartmental Response to a Duodenoscope Used on a CRE Patient: A Case Study

Transmission of carbapenem-resistant Enterobacteriaceae (CRE) via duodenoscopes, specialized endoscopes used during endoscopic retrograde cholangiopancreatography (ERCP) procedures, has attracted media attention since early 2015. This attention has placed increasing focus on the reprocessing of duodenoscopes. Current reprocessing recommendations for these endoscopes require either high-level disinfection or ethylene oxide sterilization. While reprocessing duodenoscopes, staff at endoscopy locations within the Mercy health system perform a single high-level disinfection cycle that is preceded by two cycles of manual cleaning. The Mercy system has 37 locations for gastrointestinal endoscopic procedures and nine that can accommodate patients requiring ERCP. In early 2016, the Mercy Oklahoma City location performed an ERCP on a patient known prior to the case to be a carrier of CRE. After the case, multiple departments located in both the Oklahoma City and St. Louis facilities partnered to culture and sterilize the duodenoscope used in that case to ensure its safety for use on subsequent patients. This case study presents the situation and discusses culturing of endoscopes. In light of the evidence presented, the importance of enhanced communication and cooperation to achieve patient safety should be paramount to all other factors.

Is a chlorine dioxide wiping procedure suitable for the high-level disinfection of nasendoscopes?

BACKGROUND

Nasendoscopes are widely used in the outpatient ENT setting. Their reprocessing requires high-level disinfection (HLD). Recently, a wiping procedure using chlorine dioxide (ClO₂) has been proposed as an alternative to HLD traditional procedures.

OBJECTIVE

To assess the effectiveness of the HLD wiping procedure versus soaking procedure on a contaminated nasendoscope.

METHOD

A nasendoscope was contaminated with four strains of bacteria and Bacillus subtilis spores. After HLD either with the wiping procedure or with the soaking procedure (PA), the reduction of the initial contamination was determined.

FINDINGS

The wiping procedure with ClO₂ displayed more than 5 log reduction for vegetative bacteria after 30 s contact time (CT) and 4 log reduction on B. subtilis spores after 2 min CT. The soaking procedure with PA displayed similar results on planktonic bacteria after 10 min CT but the log reduction of B. subtilis remained below 4.

CONCLUSION

The ClO₂ wiping procedure showed bactericidal and sporicidal efficacy on a contaminated nasendoscope in a shorter time compared to the PA soaking procedure. Thus, ClO₂ wiping procedure might be considered as an alternative to the traditional HLD procedure for nasendoscopes.

Duodenoscopy related infection risk and duodenoscope cleaning and disinfection

With the development of minimally invasive techniques, duodenoscope, as an instrument for diagnosis and treatment of pancreaticobiliary diseases, has been gradually applied in clinical practice. Iatrogenic infection caused by duodenoscopy is a well-documented complication, which has gained extensive attention especially in duodenoscope cleaning and disinfecting. It has been postulated that the complexity in design of duodenoscope makes cleaning difficult and poses a risk for nosocomial infections. As such, it is of positive practical significance to analyze the factors that affect cleaning and disinfecting and to take effective measures to do them better, in order to prevent nosocomial infection. This paper briefly reviews the cleaning and sterilizing of duodenoscope and the risk of infection associated with duodenoscopy.

Current Practice of Duodenoscope Reprocessing

Numerous outbreaks of duodenoscope-associated transmission of multi-drug resistant bacteria have recently been reported. Unlike prior episodes of endoscope-transmitted infections, the latest outbreaks have occurred despite strict adherence to duodenoscope reprocessing guidelines. The current standard for all flexible endoscope reprocessing includes pre-cleaning, leak testing, an additional manual cleaning step, and high-level disinfection. When these steps are strictly followed, the risk of infection transmission during endoscopy is exceedingly rare. However, due to its complex design, the duodenoscope may not be able to be adequately disinfected using the current reprocessing standards. Supplemental measures to enhance scope reprocessing have subsequently been recommended to reduce the infection risk in patients undergoing endoscopic retrograde cholangiopancreatography. These methods are likely short-term solutions that have yet to be validated regarded their effectiveness. Additional approaches to monitor the quality of duodenoscope reprocessing may also be useful. Ultimately, a definitive, yet logistically feasible, method of duodenoscope reprocessing is required to ensure the safety of our patients.

Complications of diagnostic colonoscopy, upper endoscopy, and enteroscopy

Endoscopy is an inherent and an invaluable tool in every gastroenterologist's armamentarium. The prerequisite for quality and safety remains foremost. Adverse events should be minimized and proactive steps should taken before, during and after the endoscopic procedure. Upper endoscopy and colonoscopy are part of basic endoscopy and their major complications will be reviewed here, together with those of enteroscopy. The most common of all endoscopy related complications are cardiopulmonary and thus they will be addressed in detail first. Colonoscopy's major complications are bleeding and perforation. Their epidemiology, mechanisms/risk factors, diagnosis, treatment and prevention will be addressed. The incidence of both of these complications increases significantly with polypectomy. Thus clinical judgment and experience in both polypectomy techniques and the ways to treat these complications, especially with the advanced endoscopic options advanced in the last decade, are of paramount importance. Post-polypectomy syndrome, infection and gas explosion are less frequent and will be reviewed briefly. Bleeding and perforation are upper endoscopy's major complications as well. Advances in endoscopic techniques in recent years offer endoscopic treatment instead of directly resorting to surgery, as was used to be the case and still is if the first fails. Enteroscopy is generally a more advanced procedure and overall complication rate is often quoted as 1%, most of them have been attributed to the passage of the overtube. Perforation and bleeding are the major complications, and a unique upper enteroscopy-associated complication is pancreatitis.

Developing the Pediatric Gastrointestinal Endoscopy Unit: A Clinical Report by the Endoscopy and Procedures Committee

There is significant variability in the design and management of pediatric endoscopy units. Although there is information on adult endoscopy units, little guidance is available to the pediatric endoscopy practitioner. The purpose of this clinical report, prepared by the NASPGHAN Endoscopy and Procedures Committee, is to review the important considerations for setting up an endoscopy unit for children. A systematic review of the literature was undertaken in the preparation of this report regarding the design, management, needed equipment, motility setup, billing and coding, and pediatric specific topics.

A pilot study on using chlorine dioxide gas for disinfection of gastrointestinal endoscopes

OBJECTIVES

This pilot study of employing chlorine dioxide (CD) gas to disinfect gastrointestinal endoscopes was conducted to meet the expectations of many endoscopy units in China for a high-efficiency and low-cost disinfectant.

METHODS

An experimental prototype with an active circulation mode was designed to use CD gas to disinfect gastrointestinal endoscopes. One type of testing device composed of polytetrafluoroethylene (PTFE) tubes (2 m long, inner diameter 1 mm) and bacterial carrier containers was used to simulate the channel of the endoscope. PTFE bacterial carriers inoculated with Bacillus atrophaeus with or without organic burden were used to evaluate the sporicidal activity of CD gas. Factors including exposure dosage, relative humidity (RH), and flow rate (FR) influencing the disinfection effect of CD gas were investigated. Moreover, an autoptic disinfecting test on eight real gastrointestinal endoscopes after clinical use was performed using the experimental prototype.

RESULTS

RH, exposure dosage, organic burden, and the FR through the channel significantly (P<0.05) affected the disinfection efficacy of CD gas for a long and narrow lumen. The log reduction increased as FR decreased. Treatment with 4 mg/L CD gas for 30 min at 0.8 L/min FR and 75% RH, resulted in complete inactivation of spores. Furthermore, all eight endoscopes with a maximum colony-forming unit of 915 were completely disinfected. The cost was only 3 CNY (0.46 USD) for each endoscope.

CONCLUSIONS

The methods and results reported in this study could provide a basis for further studies on using CD gas for the disinfection of endoscopes.

Risk factors associated with the transmission of carbapenem-resistant Enterobacteriaceae via contaminated duodenoscopes

BACKGROUND AND AIMS

The duodenoscopes used to perform ERCP have been implicated in several outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) infection. The risk factors for CRE transmission via contaminated duodenoscopes remain unclear.

METHODS

In this retrospective, single-center, case-control study, all patients who underwent ERCP with either 1 of 2 contaminated duodenoscopes were evaluated. We compared the patients who acquired CRE (active infection or colonization) with those who did not.

RESULTS

Between October 3, 2014, and January 28, 2015, a total of 125 procedures were performed on 115 patients by using either of the contaminated duodenoscopes. Culture data were available for 104 of the 115 exposed patients (90.4%). Among these patients, 15 (14.4%) became actively infected (n = 8, 7.7%) or colonized (n = 7, 6.7%) with CRE. On univariate analysis, recent antibiotic exposure (66.7% vs 37.1%; P = .046), active inpatient status (60.0% vs 28.1%; P = .034), and a history of cholangiocarcinoma (26.7% vs 3.4%; P = .008) were patient characteristics associated with an increased risk of CRE infection. Biliary stent placement (53.3% vs 22.5%; P = .024) during ERCP was a significant procedure-related risk factor. After adjusting for cholangiocarcinoma, biliary stent placement (odds ratio 3.62; 95% confidence interval, 1.12-11.67), and active inpatient status (odds ratio 3.74; 95% confidence interval, 1.15-12.12) remained independent risk factors for CRE transmission.

CONCLUSIONS

In patients undergoing ERCP with a contaminated duodenoscope, biliary stent placement, a diagnosis of cholangiocarcinoma, and active inpatient status are associated with an increased risk of CRE transmission.

Simulated-use validation of a sponge ATP method for determining the adequacy of manual cleaning of endoscope channels

Background

The objective of this study was to validate the relative light unit (RLU) cut-off of adequate cleaning of flexible colonoscopes for an ATP (adenosine tri-phosphate) test kit that used a sponge channel collection method.

Methods

This was a simulated-use study. The instrument channel segment of a flexible colonoscope was soiled with ATS (artificial test soil) containing approximately 8 Log₁₀Enterococcus faecalis and Pseudomonas aeruginosa/mL. Full cleaning, partial cleaning and no cleaning were evaluated for ATP, protein and bacterial residuals. Channel samples were collected using a sponge device to assess residual RLUs. Parallel colonoscopes inoculated and cleaned in the same manner were sampled using the flush method to quantitatively assess protein and bacterial residuals. The protein and viable count benchmarks for adequate cleaning were <6.4 ug/cm² and <4 Log₁₀ cfu/cm².

Results

The negative controls for the instrument channel, over the course of the study remained low with on average 14 RLUs, 0.04 ug/cm² protein and 0.025 Log₁₀ cfu/cm². Partial cleaning resulted in an average of 6601 RLUs, 3.99 ug/cm², 5.25 Log₁₀ cfu/cm²E. faecalis and 4.48 Log₁₀ cfu/cm²P. aeruginosa. After full cleaning, the average RLU was 29 (range 7–71 RLUs) and the average protein, E. faecalis and P. aeruginosa residuals were 0.23 ug/cm², 0.79 and 1.61 Log₁₀ cfu/cm², respectively.

Conclusions

The validated cut-off for acceptable manual cleaning was set at ≤100 RLUs for the sponge collected channel ATP test kit.

Duodenoscope-Associated Bacterial Infections: A Review and Update

OPINION STATEMENT

Physicians depend on the use of flexible endoscopes for delivery of vital care that is morbidity sparing compared to surgical alternatives. Iatrogenic infection is a well-documented complication of therapeutic endoscopy. Recent emergence of unique antimicrobial resistance patterns and molecular "fingerprinting" of bacteria harken a new era in duodenoscope-related infections which occur in spite of compliance with device manufacturer-recommended protocols for high-level disinfection (HLD). Further studies suggest that these protocols are likely inadequate. Endoscopic retrograde cholangiopancreatography (ERCP) remains critical in the provision of minimally invasive diagnostic, therapeutic, and palliative care for patients with pancreaticobiliary disease. This manuscript reviews the history of duodenoscope-related infections, current challenges to scope reprocessing, and recommendations from regulatory agencies.

Hygiene: The Looming Achilles Heel in Endoscopy

BACKGROUND

Since the late 1970s there have been sporadic reports of nosocomial infections linked to endoscopic procedures. Infections by multidrug-resistant organisms (MDRO) have an increasing impact on healthcare systems worldwide. Since 2010 outbreaks involving MDRO have been reported as a result of endoscopic retrograde cholangiopancreatography (ERCP) from the USA, France, Germany and the Netherlands.

METHODS

This article evaluates the recent outbreaks and developments and demonstrates a structural approach to how to prevent future infections. Current national and international guidelines were used as a basis for discussions.

RESULTS

In some cases insufficient cleaning or drying supported the outbreak. In the majority of cases, outbreaks occurred despite the apparently appropriate reprocessing protocols being in use. Microlesions were identified on a number of endoscopes, which supported the growth of bacteria and represented a vehicle for the transmission of infectious material. National official bodies responded with warnings. Manufacturers informed their customers accordingly. Separate, purpose-designed reprocessing rooms and a sufficient number of competent staff provide the structural quality for a safe reprocessing. The process quality includes a thorough cleaning of all endoscope channels and crucial instrument components, followed by an automated and validated reprocessing procedure. Strict adherence to manufacturers' recommendations is essential. The outcome quality should be evaluated by regular audits, validation of reprocessing procedures and microbiological surveillance. If outbreaks occur, a close co-operation with official bodies and manufacturers is essential.

CONCLUSION

Health care professionals and manufacturers should be aware of their responsibility to ensure patient safety. A structural approach is key in prevention of endoscopy-associated infections.

Clinical Practice Guidelines for Endoscope Reprocessing

Gastrointestinal endoscopy is effective and safe for the screening, diagnosis, and treatment of gastrointestinal disease. However, issues regarding endoscope-transmitted infections are emerging. Many countries have established and continuously revise guidelines for endoscope reprocessing in order to prevent infections. While there are common processes used in endoscope reprocessing, differences exist among these guidelines. It is important that the reprocessing of gastrointestinal endoscopes be carried out in accordance with the recommendations for each step of the process.

Endoscope Reprocessing: Update on Controversial Issues

Several issues concerning endoscope reprocessing remain unresolved based on currently available data. Thus, further studies are required to confirm standard practices including safe endoscope shelf life, proper frequency of replacement of some accessories including water bottles and connecting tubes, and microbiological surveillance testing of endoscopes after reprocessing. The efficacy and cost-effectiveness of newer technology that allows automated cleaning and disinfection is one such controversial issue. In addition, there are no guidelines on whether delayed reprocessing and extended soaking may harm endoscope integrity or increase the bioburden on the external or internal device surfaces. In this review, we discuss the unresolved and controversial issues regarding endoscope reprocessing.

Recent Update on Microbiological Monitoring of Gastrointestinal Endoscopes after High-Level Disinfection

Endoscopy-related infections are important contributors to nosocomial infections. Endoscope reprocessing according to standard guidelines ensures high-level disinfection and prevents endoscopy-related infections. Microbiological surveillance may help in monitoring the effectiveness of gastrointestinal endoscope disinfection. The process involves microbial cultures and non-culture methods such as bioburden assays, adenosine triphosphate (ATP) bioluminescence, and quantitative polymerase chain reactions (PCRs). Surveillance culturing to monitor endoscopes after reprocessing has been recommended by a majority of organizations. Bioburden assays, ATP bioluminescence, and quantitative PCRs provide rapid and reliable measures. Each institution will have to try to establish its own surveillance guidelines.

A quarantine process for the resolution of duodenoscope-associated transmission of multidrug-resistant Escherichia coli

BACKGROUND

Because of their complex design, duodenoscopes have been long recognized to be difficult to fully disinfect and may play a role in transmission of bacteria between patients. Recent reports of duodenoscope-associated carbapenem-resistant enterobacteriaceae transmission have confirmed these suspicions. An outbreak of a multidrug resistant strain of Escherichia coli was recently reported at our institution. Herein we report the results of our investigation and the process improvements that we deployed in an effort to contain the outbreak.

METHODS

A full investigation into the environment, endoscopists, infection control practices, high-level disinfection process as well as endoscopes was undertaken in conjunction with the local county health authority and the Centers for Disease Control and Prevention. Duodenoscopes were cultured and quarantined for 48 hours until negative cultures were obtained. Ergonomic changes were made to the endoscope reprocessing area, duodenoscopes were returned for routine maintenance, and surveillance cultures were obtained from all patients undergoing ERCP.

RESULTS

Between November 2012 and August 2013, 32 patients were found to harbor 1 of 2 clonal strains of multidrug-resistant E coli, all of whom had undergone ERCP or duodenoscopy. A total of 1149 ERCPs were performed during this time period. Seven patients died within 31 days of the organism being identified in culture, 16 patients died overall by March 2015. The exact contribution of E coli to death is unclear because most patients had underlying late-stage malignancy or other severe medical comorbidities. No breach in high-level disinfection protocol or infection control practices was identified. The clonal strain of E coli was identified in culture on 4 of 8 duodenoscopes, 3 of which required critical repairs despite lack of obvious malfunction. The defect rate in high-level disinfection of duodenoscopes was 2% over a 1-year period. The implemented quality improvements, subsequent to which 1625 ERCPs have been performed, were successful in halting the outbreak.

CONCLUSIONS

The existing manufacturer-recommended high-level disinfection protocols for duodenoscopes are inadequate. Although the ultimate solution may be a design change to the instrument, the timeline for such a change appears long and potentially difficult to exact. In the interim, a reliable method to ensure that bacterial pathogens are not present on the duodenoscope after high-level disinfection is needed.

Persistent contamination on colonoscopes and gastroscopes detected by biologic cultures and rapid indicators despite reprocessing performed in accordance with guidelines

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.

Infectious diseases linked to cross-contamination of flexible endoscopes

Flexible endoscopes are widely used to examine, diagnose, and treat medical disorders. While the risk of endoscopy-related transmission of infection is estimated to be very low, more health care-associated infections are related to contaminated endoscopes than to any other medical device. Flexible endoscopes can get highly contaminated with microorganisms, secretions and blood during use. The narrow lumens and multiple internal channels make the cleaning of flexible endoscopes a complex and difficult task. Despite the availability of international, national and local endoscope reprocessing guidelines, contamination and transmission of microorganisms continue to occur. These transmissions are mostly related to the use of defective equipment, endoscope reprocessing failures, and noncompliance with recommended guidelines. This article presents an overview of publications about case reports and outbreaks related to contamination of flexible endoscopes.

Complications during colonoscopy: prevention, diagnosis, and management

Colonoscopy is largely performed in daily clinical practice for both diagnostic and therapeutic purposes. Although infrequent, different complications may occur during the examination, mostly related to the operative procedures. These complications range from asymptomatic and self-limiting to serious, requiring a prompt medical, endoscopic or surgical intervention. In this review, the complications that may occur during colonoscopy are discussed, with a particular focus on prevention, diagnosis, and therapeutic approaches.

Evaluation of the Quality of Reprocessing of Gastrointestinal Endoscopes

OBJECTIVES

To evaluate the quality of gastrointestinal endoscope reprocessing and discuss the advantages of microbiological surveillance testing of these endoscopes.

METHODS

Retrospective analysis of the results of endoscope sampling performed from October 1, 2006, through December 31, 2014, in a gastrointestinal endoscopy unit of a teaching hospital equipped with 89 endoscopes and 3 automated endoscope reprocessors, with an endoscopy quality assurance program in place. The compliance rate was defined as the proportion of the results classified at target or alert levels according to the French guidelines. A multivariate analysis (logistic regression) was used to identify the parameters influencing compliance.

RESULTS

A total of 846 samples were taken. The overall compliance rate was 86% and differed significantly depending on the sampling context (scheduled or not scheduled), the type of endoscope, and the season. No other parameter was associated with compliance. A total of 118 samples carried indicator microorganisms such as Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Enterobacteriaceae, and Candida sp.

CONCLUSION

The systematic use of an automated endoscope reprocessor does not provide totally satisfactory compliance. Microbiological surveillance is indispensable to monitor reprocessing, reinforce good practices (endoscopes, reprocessing units), and detect endoscopes requiring early technical maintenance.

Endoscope storage time: assessment of microbial colonization up to 21 days after reprocessing

BACKGROUND

Insufficient data exist for how long endoscopes can be stored after reprocessing. Concern about possible microbial colonization has led to various recommendations for reprocessing intervals among institutions, with many as short as 5 days. A significant cost savings could be realized if it can be demonstrated that endoscopes may be stored for as long as 21 days without risk of clinically significant contamination.

OBJECTIVE

To demonstrate whether flexible endoscopes may be stored for as long as 21 days after reprocessing without colonization by pathogenic microbes.

DESIGN

Prospective, observational study.

SETTING

Tertiary care center.

ENDOSCOPES

Four duodenoscopes, 4 colonoscopes, and 2 gastroscopes.

INTERVENTION

Microbial testing of endoscope channels.

MAIN OUTCOME MEASUREMENTS

Culture results at days 0, 7, 14, and 21.

RESULTS

There were 33 positive cultures from 28 of the 96 sites tested (29.2% overall contamination rate). Twenty-nine of 33 isolates were typical skin or environmental contaminants, thus clinically insignificant. Four potential pathogens were cultured, including Enterococcus, Candida parapsilosis, α-hemolytic Streptococcus, and Aureobasidium pullulans; all were likely clinically insignificant as each was only recovered at 1 time point at 1 site, and all grew in low concentrations. There were no definite pathogenic isolates.

LIMITATIONS

Single center.

CONCLUSION

Endoscopes can be stored for as long as 21 days after standard reprocessing with a low risk of pathogenic microbial colonization. Extension of reprocessing protocols to 21 days could effect significant cost savings.

High-level disinfection of gastrointestinal endoscope reprocessing

High level disinfection (HLD) of the gastrointestinal (GI) endoscope is not simply a slogan, but rather is a form of experimental monitoring-based medicine. By definition, GI endoscopy is a semicritical medical device. Hence, such medical devices require major quality assurance for disinfection. And because many of these items are temperature sensitive, low-temperature chemical methods, such as liquid chemical germicide, must be used rather than steam sterilization. In summarizing guidelines for infection prevention and control for GI endoscopy, there are three important steps that must be highlighted: manual washing, HLD with automated endoscope reprocessor, and drying. Strict adherence to current guidelines is required because compared to any other medical device, the GI endoscope is associated with more outbreaks linked to inadequate cleaning or disinfecting during HLD. Both experimental evaluation on the surveillance bacterial cultures and in-use clinical results have shown that, the monitoring of the stringent processes to prevent and control infection is an essential component of the broader strategy to ensure the delivery of safe endoscopy services, because endoscope reprocessing is a multistep procedure involving numerous factors that can interfere with its efficacy. Based on our years of experience in the surveillance of culture monitoring of endoscopic reprocessing, we aim in this study to carefully describe what details require attention in the GI endoscopy disinfection and to share our experience so that patients can be provided with high quality and safe medical practices. Quality management encompasses all aspects of pre- and post-procedural care including the efficiency of the endoscopy unit and reprocessing area, as well as the endoscopic procedure itself.

Correlation between the growth of bacterial biofilm in flexible endoscopes and endoscope reprocessing methods

BACKGROUND

The purpose of this article was to investigate bacterial biofilm formed on endoscopes and to explore the possible correlation between endoscope reprocessing procedures and bacterial biofilm growth on endoscope channels.

METHODS

Sixty-six endoscope suction and biopsy channels and 13 water and air channels were collected from 66 hospitals throughout China. Scanning electron microscopy was used to observe biofilm growth on the internal surface of these channels. Questionnaires were mailed to 66 endoscopy centers to investigate reprocessing procedures for endoscopes.

RESULTS

Obvious biofilm growth was detected on 36 suction and biopsy channels (36/66, 54.6%) and 10 water and air channels (10/13, 76.9%). The percentage of manual cleaning in group B (n = 36, without detection of biofilms) was 92.3% (33/36), whereas it was 50.0% (15/30) in group A (n = 30, with detection of biofilms). Follow-up of group A (n = 30) showed that no biofilm was detected, whereas biofilm was detected in group B. The difference was statistically significant (P = .001). The proportion of detergent reuse in group B was 92.3% (33/36), and it was 61.5% in group A (18/30) (P = .005). The proportion of alcohol-air drying in group B was 38.9% (14/36), and it was 76.7% (23/30) in group A (P = .002).

CONCLUSION

The formation of endoscopic biofilm during clinical practice may be related to reuse of detergent, manual cleaning, and incomplete drying.