Epidemiology and Prevention of Infections Related to Endoscopy

Microbiological characteristics, transmission routes, and mitigation measures in bronchoscope-associated investigations: Summary of Centers for Disease Control and Prevention (CDC) consultations, 2014-2022

In this summary of US Centers for Disease Control and Prevention (CDC) consultations with state and local health departments concerning their bronchoscope-associated investigations from 2014 through 2022, bronchoscope reprocessing gaps and exposure to nonsterile water sources appeared to be the major routes of transmission of infectious pathogens, which were primarily water-associated bacteria.

Cross-contamination rate of reusable flexible bronchoscopes: A systematic literature review and meta-analysis

Background

Bronchoscopy is generally a safe and efficient procedure. However, the risk of cross-contamination with reusable flexible bronchoscopes (RFB) has been detected in several outbreaks worldwide.

Aim

To estimate the average cross-contamination rate of patient-ready RFBs based on available published data.

Methods

We performed a systematic literature review in PubMed and Embase to investigate the cross-contamination rate of RFB. Included studies identified indicator organisms or colony forming units (CFU) levels, and total number of samples >10. The Contamination threshold was defined according to the European Society of Gastrointestinal Endoscopy and European Society of Gastrointestinal Endoscopy Nurse and Associates (ESGE-ESGENA) guidelines. To calculate the total contamination rate, a random effects model was applied. Heterogeneity was analysed via a Q-test and illustrated in a forest plot. Publication bias was analysed via the Egger’s regression test and illustrated in a funnel plot.

Results

Eight studies fulfilled our inclusion criteria. The random effects model included 2169 samples and 149 events (positive tests). The total RFB cross-contamination rate was 8.69% ± 1.86 (standard division [SD]) (95% confidence interval [CI]: 5.06–12.33%). The result showed significant heterogeneity of 90% and publication bias.

Discussion

Significant heterogeneity and publication bias is likely associated with varying methodology and aversion towards publishing negative findings, respectively. Based on the cross-contamination rate an infection control paradigm shift is needed to ensure patient safety. We recommend to follow the Spaulding classification and classify RFBs as critical items. Accordingly, infection control measures such as obligatory surveillance, and implementing single-use alternatives must be considered where feasible.

High Prevalence Rate of Microbial Contamination in Patient-Ready Gastrointestinal Endoscopes in Tehran, Iran: an Alarming Sign for the Occurrence of Severe Outbreaks

An alarmingly increasing number of outbreaks caused by contaminated gastrointestinal (GI) endoscopes are being reported as a particularly concerning issue. This study is the first large-scale multicenter survey to evaluate the contamination of GI endoscopes in Tehran, Iran. This multicenter study was conducted among 15 tertiary referral and specialized gastrointestinal settings. Reprocessed GI endoscopes were sampled by the sequence of the flush-brush-flush method. Bacterial and viral contamination, as well as antimicrobial resistance, were explored by culture and molecular assays. A total of 133 reprocessed and ready-to-use GI endoscopes were investigated. In phase I and phase II, 47% and 32%, respectively, of the GI endoscopes were determined to be contaminated. GI flora was the most prevalent contaminant isolated from GI endoscopes, in which the most predominant bacteria were Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae, in both phase I and II evaluations. The majority of the isolated bacteria in the current study were considered multidrug-resistant organisms (MDROs). More importantly, we recovered carbapenem-resistant nonfermentative Gram-negative bacilli (CRNFGNB), carbapenem-resistant Enterobacterales (CRE), extended-spectrum β-lactamase (ESBL)-producing Enterobacterales (ESBL-E), multidrug-resistant Clostridioides difficile, vancomycin-resistant Enterococcus (VRE), and drug-resistant Candida spp. Disconcertingly, our molecular assays revealed contamination of some reprocessed GI endoscopes with hepatitis B virus (HBV), hepatitis C virus (HCV), and even HIV. This multicenter study indicates a higher-than-expected contamination rate among reprocessed and ready-for-patient-use GI endoscopes, which suggests a higher-than-expected endoscopy-associated infection (EAI) risk, and potentially, morbidity and mortality rate, associated with endoscopy procedures in Tehran, Iran. IMPORTANCE In the light of severe outbreaks caused by multidrug-resistant microorganisms due to contaminated GI endoscopes, understanding to what extent GI endoscopes are inadequately reprocessed is crucial. Several studies assessed contamination of GI endoscopes with various outcomes across the world; however, the prevalence and risk factors of contaminated GI endoscopes and potential subsequent nosocomial spread are still unknown in Iran. The present study is the first large-scale multicenter survey to evaluate the microbial contamination of repossessed and ready-to-use GI endoscopes in Tehran, Iran. Our study showed a higher-than-expected contamination rate among reprocessed GI endoscopes, which suggests potential seeding of deadly but preventable outbreaks associated with endoscopy procedures in Iran. These results suggest that the current reprocessing and process control guidelines do not suffice in Iran. The current study is of particular importance and could provide insights into unrecognized and unidentified endoscopy-associated outbreaks in Iran.

Gastrointestinal Endoscopy-Associated Infections: Update on an Emerging Issue

Over 17.7 million gastrointestinal (GI) endoscopic procedures are performed annually, contributing to 68% of all endoscopic procedures in the United States. Usually, endoscopic procedures are low risk, but adverse events may occur, including cardiopulmonary complications, bleeding, perforation, pancreatitis, cholangitis, and infection. Infections after the GI endoscopies most commonly result from the patient's endogenous gut flora. Although many studies have reported infection after GI endoscopic procedures, a true estimate of the incidence rate of post-endoscopy infection is lacking. In addition, the infection profile and causative organisms have evolved over time. In recent times, multi-drug-resistant microorganisms have emerged as a cause of outbreaks of endoscope-associated infections (EAI). In addition, lapses in endoscope reprocessing have been reported, with some but not all outbreaks in recent times. This systematic review summarizes the demographical, clinical, and management data of EAI events reported in the literature. A total of 117 articles were included in the systematic review, with the majority reported from North America and Western Europe. The composite infection rate was calculated to be 0.2% following GI endoscopic procedures, 0.8% following ERCP, 0.123% following non-ERCP upper GI endoscopic procedures, and 0.073% following lower GI endoscopic procedures. Pseudomonas aeruginosa was the most common culprit organism, followed by other Enterobacteriaceae groups of organisms and Gram-positive cocci. We have also elaborated different prevention methods such as antimicrobial prophylaxis, adequate sterilization methods for reprocessing endoscopes, periodic surveillance, and current evidence supporting their utilization. Finally, we discuss disposable endoscopes, which could be an alternative to reprocessing to minimize the chances of EAIs with their effects on the environmental and financial situation.

[Single-use products in endoscopy-from consumables to single-use scopes]

Clinically relevant infections triggered by the use of flexible endoscopes and respective consumables have become the focus of clinical and scientific interest in the literature. Endoscopy-associated infections can be assigned to one of two groups: (i) endogenous infections are triggered by the spread of the patient's own local flora and (ii) exogenous infections result from transmission of contaminated material or endoscopes. The number of reported infectious complications in flexible endoscopy is low but likely underestimated due to inadequate surveillance strategies and lack of clinical symptoms. To prevent exogenous infections, single-use endoscopes were brought to the market. Single-use bronchoscope have been part of routine clinical care for years, while single-use duodenoscopes have only recently been approved. The increased patient safety and economic costs were clearly evaluated for the single-use bronchoscopes, but this still needs to be studied for single-use duodenoscopes. The use of single-use endoscopes-at first glance-represents an additional financial burden on the healthcare system. However, in addition to the material costs of disposable endoscopes, the costs that are avoided by them (e.g., prolonged hospitalization, intensive care treatment, and follow-up interventions) must also be included in the overall calculation.

Risk Communication After Health Care Exposures: An Experimental Vignette Survey With Patients

Purpose. We investigated how health care systems should communicate with patients about possible exposures to blood-borne pathogens that may have occurred during their care. Our goal was to determine how best to communicate uncertain risk information in a way that would minimize harm to patients, maintain their trust, and encourage patients to seek follow-up treatment. Methods. Participants (N = 1103) were randomized to receive one of six vignette surveys; 997 (98.4%) responded. All vignettes described the same event, but differed by risk level and recommendations (lower risk v. higher risk) and by communication mode (telephone, letter, social media). We measured participants’ perceived risk of blood-borne infection, trust in the health care system, and shared decision making about next clinical steps. Open-ended questions were analyzed using grounded thematic analysis. Results. When the vignette requested patients to undergo testing and practice certain health behaviors (higher risk), participants’ likelihood of seeking follow-up testing for blood-borne pathogens and their understanding of health issues increased. Perceived trust was unaffected by risk level or communication processes. Qualitative data indicated a desire for telephone communication from providers known to the patient. Limitations. It is not clear whether higher risk language or objective risk levels in vignettes motivated patients’ behavioral intentions. Conclusion. Using higher risk language when disclosing large-scale adverse events increased participants’ willingness to seek follow-up care. Implications. Health care organizations’ disclosures should focus on the next steps to take after health care exposures. This communication should involve helping patients to understand their personal health issues better, make them feel that they know which steps to take following the receipt of this information, and encouraging them to seek follow-up infectious disease testing in order to better take care of themselves.

Enzymatic detergent reuse in gastroscope processing: a potential source of microorganism transmission

OBJECTIVE

to evaluate the potential contamination of enzymatic detergent from its reuse and to identify the microbiological profile in the solution used to clean gastrointestinal endoscopic devices.

METHOD

cross-sectional study based on microbiological analysis of 76 aliquots of 19 different enzymatic detergent solutions used to clean endoscopic devices. The aliquots were homogenized, subjected to Millipore® 0.45 µm membrane filtration and the presumptive identification of microorganisms was performed by biochemical-physiological methods according to previously established specific bacterial groups that are of clinical and epidemiological relevance.

RESULTS

the mean values, as well as the standard deviation and the median, of the enzymatic detergent microbial load increased as the solution was reused. There was a significant difference between the means of after first use and after fifth reuse. A total of 97 microorganisms were identified, with predominance of the coagulase-negative Staphylococcus, Pseudomonas spp., Klebsiella spp., Enterobacter spp. genus, and Escherichia coli species.

CONCLUSION

the reuse of the enzymatic detergent solution is a risk to the safe processing of endoscopic devices, evidenced by its contamination with pathogenic potential microorganisms, since the enzymatic detergent has no bactericidal property and can contribute as an important source for outbreaks in patients under such procedures.

A systematic review and cost effectiveness analysis of reusable vs. single-use flexible bronchoscopes

The cost effectiveness of reusable vs. single‐use flexible bronchoscopy in the peri‐operative setting has yet to be determined. We therefore aimed to determine this and hypothesised that single‐use flexible bronchoscopes are cost effective compared with reusable flexible bronchoscopes. We conducted a systematic review of the literature, seeking all reports of cross‐contamination or infection following reusable bronchoscope use in any clinical setting. We calculated the incidence of these outcomes and then determined the cost per patient of treating clinical consequences of bronchoscope‐induced infection. We also performed a micro‐costing analysis to quantify the economics of reusable flexible bronchoscopes in the peri‐operative setting from a high‐throughput tertiary centre. This produced an accurate estimate of the cost per use of reusable flexible bronchoscopes. We then performed a cost effectiveness analysis, combining the data obtained from the systematic review and micro‐costing analysis. We included 16 studies, with a reported incidence of cross‐contamination or infection of 2.8%. In the micro‐costing analysis, the total cost per use of a reusable flexible bronchoscope was calculated to be £249 sterling. The cost per use of a single‐use flexible bronchoscope was £220 sterling. The cost effectiveness analysis demonstrated that reusable flexible bronchoscopes have a cost per patient use of £511 sterling due to the costs of treatment of infection. The findings from this study suggest benefits from the use of single‐use flexible bronchoscopes in terms of cost effectiveness, cross‐contamination and resource utilisation.

Duodenoscope-Associated Infections: Update on an Emerging Problem

The duodenoscope is among the most complex medical instruments that undergo disinfection between patients. Transmission of infection by contaminated scopes has remained a challenge since its inception. Notable risk factors for pathogen transmission include non-adherence to disinfection guidelines, encouragement of biofilm deposition due to complex design and surface defects and contaminated automated endoscope reprocessors. The most common infections following endoscopy are endogenous infections involving the patient's own gut flora. Exogenous infections, on the other hand, are associated with contaminated scopes and can theoretically be prevented by effective reprocessing. Pseudomonas aeruginosa is currently the most common organism isolated from contaminated endoscopes. Of note, reports of multidrug-resistant duodenoscopy-associated outbreaks have surfaced recently, many of which occurred despite adequate reprocessing. The FDA and CDC currently recommend comprehensive cleaning followed with at least high-level disinfection for reprocessing of flexible GI endoscopes. Reports of duodenoscope-related outbreaks despite compliance with established guidelines have prompted professional and government bodies to revisit existing guidelines and offer supplementary recommendations for duodenoscope processing. For the purposes of this review, we identified reports of duodenoscope-associated infections from 2000 till date. For each outbreak, we noted the organisms isolated, the number of cases reported, any possible explanations of contamination, and the measures undertaken to end each outbreak. We have also attempted to present an overview of recent developments in this rapidly evolving field.

Transmission of Mobile Colistin Resistance (mcr-1) by Duodenoscope

BACKGROUND

Clinicians increasingly utilize polymyxins for treatment of serious infections caused by multidrug-resistant gram-negative bacteria. Emergence of plasmid-mediated, mobile colistin resistance genes creates potential for rapid spread of polymyxin resistance. We investigated the possible transmission of Klebsiella pneumoniae carrying mcr-1 via duodenoscope and report the first documented healthcare transmission of mcr-1-harboring bacteria in the United States.

METHODS

A field investigation, including screening targeted high-risk groups, evaluation of the duodenoscope, and genome sequencing of isolated organisms, was conducted. The study site included a tertiary care academic health center in Boston, Massachusetts, and extended to community locations in New England.

RESULTS

Two patients had highly related mcr-1-positive K. pneumoniae isolated from clinical cultures; a duodenoscope was the only identified epidemiological link. Screening tests for mcr-1 in 20 healthcare contacts and 2 household contacts were negative. Klebsiella pneumoniae and Escherichia coli were recovered from the duodenoscope; neither carried mcr-1. Evaluation of the duodenoscope identified intrusion of biomaterial under the sealed distal cap; devices were recalled to repair this defect.

CONCLUSIONS

We identified transmission of mcr-1 in a United States acute care hospital that likely occurred via duodenoscope despite no identifiable breaches in reprocessing or infection control practices. Duodenoscope design flaws leading to transmission of multidrug-resistant organsisms persist despite recent initiatives to improve device safety. Reliable detection of colistin resistance is currently challenging for clinical laboratories, particularly given the absence of a US Food and Drug Administration-cleared test; improved clinical laboratory capacity for colistin susceptibility testing is needed to prevent the spread of mcr-carrying bacteria in healthcare settings.

Outbreak of Hospital Infection from Biofilm-embedded Pan Drug-resistant Pseudomonas aeroginosa, Due to a Contaminated Bronchoscope

Background

Colistin-resistant Pseudomonas aeruginosa (P. aeruginosa) has been defined as pandrug-resistant (PDR) strain. Outbreaks of PDR P. aeruginosa especially in pulmonary tract infections due to contaminated bronchoscopes have rarely been reported. The emergence of pandrug-resistant strains in both CF (Cystic Fibrosis) and non-CF clinical isolates over recent years remains of a great concern. Hospital wards contaminated with PDR P. aeruginosa infection, must be shot down until their eradication. Health Authorities must be informed immediately and infection control strategies must be implemented.

Aim

To report such an outbreak and modify the infection control strategy in an academic hospital in Ankara Turkey.

Methods

From October to December 2013, PDR-Pseudomonas aerogionsa were identified from bronchial cultures of 15 patients who had undergone bronchoscopy prior to the infection. Three batches of surveillance cultures were obtained from the environmental objects and healthcare workers related to the procedures. Pulsed-field gel electrophoresis (PFGE) was used for bacterial typing. Antimicrobial susceptibility was assessed by disc diffusion and E-test methods.

Findings

A total of 70 specimens were obtained during the first surveillance operation. One Colistin-resistant P. aeroginosa was isolated from a bronchoscope. Although the disinfection protocols for bronchoscope were revised and implemented, seven additional bronchial cases were identified thereafter. The pathogen was identified from two subsequent surveillance cultures and was not eliminated until Ethylene oxide sterilization was added to the disinfection protocol. PFGE revealed that all 15 isolates from the patients and the three isolates from the bronchoscope shared a common pattern with minor variance. XbaI restriction enzyme turned out better than SpeI in interpreting bacterial pulse types with BioNumerics 6.0. The most suitable cut off value for SpeI was above 80% Dice similarity while for XbaI above 95%Dice similarity with BioNumerics 6.0.

Conclusion

The outbreak of "Colistin" pan drug-resistant Pseudomonas aeroginosa was caused by a contaminated bronchoscope and was terminated by the implementation of a revised disinfection protocol for bronchoscope.

Endoscope drying and its pitfalls

Inadequate drying of endoscope channels is a possible cause of replication and survival of remaining pathogens during storage. The presence during storage of potentially contaminated water in endoscope channels may promote bacterial proliferation and biofilm formation. An incomplete drying procedure or lack of drying and not storing in a vertical position are the most usual problems identified during drying and endoscope storage. Inadequate drying and storage procedures, together with inadequate cleaning and disinfection, are the most important sources of endoscope contamination and post-endoscopic infection. Flexible endoscopes may be dried in automated endoscope reprocessors (AERs), manually, or in drying/storage cabinets. Flushing of the endoscope channels with 70-90% ethyl or isopropyl alcohol followed by forced air drying is recommended by several guidelines. Current guidelines recommend that flexible endoscopes are stored in a vertical position in a closed, ventilated cupboard. Drying and storage cabinets have a drying system that circulates and forces the dry filtered air through the endoscope channels. Endoscope reprocessing guidelines are inconsistent with one another or give no exact recommendations about drying and storage of flexible endoscopes. There is no conclusive evidence on the length of time endoscopes can be safely stored before requiring re-disinfection and before they pose a contamination risk. To minimize the risk of disease transmission and nosocomial infection, modification and revision of guidelines are recommended as required to be consistent with one another.

Early Assessment of the Likely Cost Effectiveness of Single-Use Flexible Video Bronchoscopes

BACKGROUND

Bronchoscopic procedures are common in the clinical setting, with estimates indicating 500,000 are undertaken per year in the USA alone. These procedures are generally regarded as safe. Unfortunately, a risk of cross-contamination between patients, with possible subsequent infection, is associated with the re-usable technology typically used in these procedures.

OBJECTIVE

Our objective was to conduct an early cost-effectiveness analysis (CEA) of single-use flexible video bronchoscope technology compared with the current reusable technology in a US hospital intensive care setting.

METHODS

We conducted a CEA to determine an incremental cost-effectiveness ratio (ICER), and constructed a decision analytic model based on the best available evidence from a literature search and a Delphi panel. We also conducted several one- and two-way sensitivity analyses and a probabilistic sensitivity analysis to illuminate the uncertainty associated with the estimates.

RESULTS

The literature search showed ample evidence of risk, albeit little of it was quantifiable. Estimates from the Delphi method found approximately a 3% risk of cross-contamination and approximately a 21% risk of subsequent infection. Pneumonia was estimated as the most likely manifestation of infection. The CEA showed a saving of $US118 per procedure and elimination of 0.7% of the risk of infection with the single-use technology. Relevant sensitivity analyses generally validated this result.

CONCLUSION

This study suggests that implementation of the single-use technology in the intensive care unit is cost effective in most scenarios. However, this result should be interpreted with caution because of the lack of certain knowledge on this particular topic.

Early Assessment of the Likely Cost Effectiveness of Single-Use Flexible Video Bronchoscopes

BACKGROUND

Bronchoscopic procedures are common in the clinical setting, with estimates indicating 500,000 are undertaken per year in the USA alone. These procedures are generally regarded as safe. Unfortunately, a risk of cross-contamination between patients, with possible subsequent infection, is associated with the re-usable technology typically used in these procedures.

OBJECTIVE

Our objective was to conduct an early cost-effectiveness analysis (CEA) of single-use flexible video bronchoscope technology compared with the current reusable technology in a US hospital intensive care setting.

METHODS

We conducted a CEA to determine an incremental cost-effectiveness ratio (ICER), and constructed a decision analytic model based on the best available evidence from a literature search and a Delphi panel. We also conducted several one- and two-way sensitivity analyses and a probabilistic sensitivity analysis to illuminate the uncertainty associated with the estimates.

RESULTS

The literature search showed ample evidence of risk, albeit little of it was quantifiable. Estimates from the Delphi method found approximately a 3% risk of cross-contamination and approximately a 21% risk of subsequent infection. Pneumonia was estimated as the most likely manifestation of infection. The CEA showed a saving of $US118 per procedure and elimination of 0.7% of the risk of infection with the single-use technology. Relevant sensitivity analyses generally validated this result.

CONCLUSION

This study suggests that implementation of the single-use technology in the intensive care unit is cost effective in most scenarios. However, this result should be interpreted with caution because of the lack of certain knowledge on this particular topic.

Contamination of single-use bronchoscopes in critically ill patients

Disposable bronchoscopes such as the Ambu aScope^TM 3 are marketed as 'single use' The risks of contamination from prolonged device storage before possible re-use are unknown. Following clinical bronchoscopy in patients whose lungs were mechanically ventilated, 20 aScope^TM 3's bronchoscopes received a standard 'social clean' and were then stored. Subsequent paired saline flush and swab samples were taken at time zero, and at 24 h and 48 h. Positive microbiological cultures were obtained from at least one time point from 16 of the 20 bronchoscopes. Pathogens considered at high risk of causing pneumonia were isolated from seven bronchoscopes, with significant quantities from six of them. Our study demonstrates that aScope^TM 3's should not be re-used on the same patient, as clinically significant growth of micro-organisms occurs frequently, despite adequate social cleaning. Culture of bronchoscopes themselves may be a potentially useful diagnostic tool in the context of pulmonary infection. Our data make it clear that these devices are single use and not single patient use.

Investigating the failure of repeated standard cleaning and disinfection of a Pseudomonas aeruginosa-infected pancreatic and biliary endoscope

Digestive endoscopy is an important technique for the diagnosis and treatment of digestive system disease. To assure medical safety, a digestive endoscope must be cleaned and disinfected before its use in an operation on the next patient. The most common treatment procedure on a digestive endoscope is high-level disinfection. The potential risk associated with digestive endoscopes is always the focus of endoscopic management in clinical practice. In this study, a polluted pancreatic and biliary endoscope after surgery was cleaned and disinfected multiple times with the standard procedure but still tested positive for Pseudomonas aeruginosa culture, which is very rare and has not been reported in China or abroad.

Public health response to a large-scale endoscopy infection control lapse in a nonhospital clinic

In 2011, a nonhospital endoscopy clinic in Ottawa, Ontario, was found to have numerous lapses in infection control procedures during an inspection by the College of Physicians and Surgeons of Ontario. The public was notified and patients who had undergone procedures at the clinic were offered testing for blood-borne pathogens. This article describes the procedure that was followed in response to the lapse, and reports the results of the tests for blood-borne pathogens as well as analyses conducted to determine whether any infections occurred as a result of the infection control lapse.

OBJECTIVE:

To determine whether transmission of blood-borne pathogens (BBPs) (hepatitis B virus [HBV], hepatitis C virus [HCV] and HIV) occurred as a result of endoscopy reprocessing failures identified during an inspection of a nonhospital endoscopy clinic in 2011.

METHODS:

The present analysis was a retrospective cohort study. Registered notification letters were mailed to 6992 patients who underwent endoscopy from 2002 to 2011 at one Canadian nonhospital endoscopy clinic, informing them of the infection control lapse and offering BBP testing. Multimedia communications and a telephone line supplemented notification. A retrospective study of patients with BBPs was performed with viral genetic testing and risk factor assessment for eligible patients. Risk for infection among patients whose procedure was within seven days of a known positive patient was compared with those whose procedure was performed more than seven days after a known postive patient. The seven-day period was selected as the period most likely to present a risk for transmission based on the documented cleaning procedures at the clinic and the available literature on virus survival.

RESULTS:

Ninety-five percent (6628 of 6992) of patients/estates were contacted and 5042 of 6728 (75%) living patients completed BBP testing. Three were newly diagnosed with HBV and 14 with HCV. Twenty-three and 48 tested positive for previously known HBV or HCV, respectively, 367 were immune to HBV due to natural infection and one was immune to HBV due to immunization. None tested positive for HIV. Sequencing did not reveal any relationships among the 46 unique case patients with viral genetic test results available. Ninety-three percent of patients reported alternative risk factors for BBP. An increased risk for infection among those who underwent a procedure within seven days of a known HBV or HCV case was not demonstrated.

CONCLUSIONS:

Endoscopy reprocessing failures were not associated with an increased risk for BBP among individuals tested.

Results from a Large-Scale Epidemiologic Look-Back Investigation of Improperly Reprocessed Endoscopy Equipment

Objective.

To determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission.

Design.

Retrospective cohort study.

Setting.

Four Veterans Affairs medical centers (VAMCs).

Patients.

Veterans who underwent colonoscopy and laryngoscopy (ear, nose, and throat [ENT]) procedures from 2003 to 2009.

Methods.

Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than 1 day prior to the case patient's procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.

Results.

Of 10,737 veterans who underwent endoscopy at 4 VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with 1 or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which 7 case patients and 8 proximate patients had sufficient viral load for further genetic testing. Only 2 of these cases, both of whom underwent laryngoscopy, and their 4 proximates agreed to further testing. None of the 4 remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the 2 case patients and 4 proximate patients ranged from 13.5% to 19.1%.

Conclusions.

Our investigation revealed that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.

Emergence of Glutaraldehyde-Resistant Pseudomonas aeruginosa

Objective.

In November 2009, routine sampling of endoscopes performed to monitor the effectiveness of the endoscope-cleaning procedure at our hospital detected Pseudomonas aeruginosa. Herein we report the results of the subsequent investigation.

Design and Methods.

The investigation included environmental cultures for source investigation, molecular analysis by pulsed-field gel electrophoresis (PFGE) to reveal the identity of the strains, and determination of the bactericidal activity of the glutaraldehyde-based disinfectant used for automated endoscope reprocessing. In addition, patient outcome was analyzed by medical chart review, and incidence rates of clinical samples with P. aeruginosa were compared.

Setting.

The University Hospital of Basel is an 855-bed tertiary care center in Basel, Switzerland. Approximately 1,700 flexible bronchoscopic, 2,500 gastroscopic, 1,400 colonoscopic, 140 endoscopic retrograde cholangiopancreatographic, and 140 endosonographic procedures are performed annually.

Results.

P. aeruginosa was detected in samples obtained from endoscopes in November 2009 for the first time since the initiation of surveillance in 2006. It was found in the rinsing water and in the drain of 1 of the 2 automated endoscope reprocessors. PFGE revealed 2 distinct P. aeruginosa strains, one in each reprocessor. The glutaraldehyde-based disinfectant showed no activity against the 2 pseudo-outbreak strains when used in the recommended concentration under standard conditions. After medical chart review, 6 patients with lower respiratory tract and bloodstream infections were identified as having a possible epidemiological link to the pseudo-outbreak strain.

Conclusions.

This is the first description of a pseudo-outbreak caused by P. aeruginosa with reduced susceptibility to an aldehyde-based disinfectant routinely used in the automated processing of endoscopes.

Results from a Large-Scale Epidemiologic Look-Back Investigation of Improperly Reprocessed Endoscopy Equipment

Objective.

To determine whether improper high-level disinfection practices during endoscopy procedures resulted in bloodborne viral infection transmission.

Design.

Retrospective cohort study.

Setting.

Four Veterans Affairs medical centers (VAMCs).

Patients.

Veterans who underwent colonoscopy and laryngoscopy (ear, nose, and throat [ENT]) procedures from 2003 to 2009.

Methods.

Patients were identified through electronic health record searches and serotested for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B virus (HBV). Newly discovered case patients were linked to a potential source with known identical infection, whose procedure occurred no more than 1 day prior to the case patient's procedure. Viral genetic testing was performed for case/proximate pairs to determine relatedness.

Results.

Of 10,737 veterans who underwent endoscopy at 4 VAMCs, 9,879 patients agreed to viral testing. Of these, 90 patients were newly diagnosed with 1 or more viral bloodborne pathogens (BBPs). There were no case/proximate pairings found for patients with either HIV or HBV; 24 HCV case/proximate pairings were found, of which 7 case patients and 8 proximate patients had sufficient viral load for further genetic testing. Only 2 of these cases, both of whom underwent laryngoscopy, and their 4 proximates agreed to further testing. None of the 4 remaining proximate patients who underwent colonoscopy agreed to further testing. Mean genetic distance between the 2 case patients and 4 proximate patients ranged from 13.5% to 19.1%.

Conclusions.

Our investigation revealed that exposure to improperly reprocessed ENT endoscopes did not result in viral transmission in those patients who had viral genetic analysis performed. Any potential transmission of BBPs from colonoscopy remains unknown.

Klebsiella spp. in endoscopy-associated infections: we may only be seeing the tip of the iceberg

PURPOSE

Two endoscopy-associated nosocomial outbreaks caused by carbapenemase-producing Klebsiella pneumoniae (CPKP) were recently observed in two German hospitals. In this study, we performed a systematic search of the medical literature in order to elucidate the epidemiology of Klebsiella spp. in endoscopy-associated outbreaks.

METHODS

Medline, the Outbreak Database ( http://www.outbreak-database.com ) and reference lists of articles extracted from these databases were screened for descriptions of endoscopy-associated nosocomial outbreaks. The data extracted and analysed were: (1) the type of medical department affected; (2) characterisation of pathogen to species and conspicuous resistance patterns (if applicable); (3) type of endoscope and the grade of its contamination; (4) number and the types of infections; (5) actual cause of the outbreak.

RESULTS

A total of seven nosocomial outbreaks were identified, of which six were outbreaks of endoscopic retrograde cholangiopancreatography-related infections and caused by contaminated duodenoscopes. Including our own outbreaks in the analysis, we identified one extended-spectrum beta-lactamase-producing K. pneumoniae strain and six CPKP strains. Insufficient reprocessing after the use of the endoscope was the main reason for subsequent pathogen transmission.

CONCLUSIONS

There were only two reports of nosocomial outbreaks due to Klebsiella spp. in the first three decades of endoscopic procedures, but seven additional outbreaks of this kind have been reported within the last 4 years. It is very likely that many of such outbreaks have been missed in the past because this pathogen belongs to the physiological gut flora. However, with the emergence of highly resistant (carbapenemase-producing) strains, strict adherence to infection control guidelines is more important than ever.

Transmission of infection by flexible gastrointestinal endoscopy and bronchoscopy

Flexible endoscopy is a widely used diagnostic and therapeutic procedure. Contaminated endoscopes are the medical devices frequently associated with outbreaks of health care-associated infections. Accurate reprocessing of flexible endoscopes involves cleaning and high-level disinfection followed by rinsing and drying before storage. Most contemporary flexible endoscopes cannot be heat sterilized and are designed with multiple channels, which are difficult to clean and disinfect. The ability of bacteria to form biofilms on the inner channel surfaces can contribute to failure of the decontamination process. Implementation of microbiological surveillance of endoscope reprocessing is appropriate to detect early colonization and biofilm formation in the endoscope and to prevent contamination and infection in patients after endoscopic procedures. This review presents an overview of the infections and cross-contaminations related to flexible gastrointestinal endoscopy and bronchoscopy and illustrates the impact of biofilm on endoscope reprocessing and postendoscopic infection.

Outbreak of ertapenem-resistant Enterobacter cloacae urinary tract infections due to a contaminated ureteroscope

BACKGROUND

Outbreaks of urinary tract infections (UTIs) due to contaminated ureteroscopes have been rarely reported.

AIM

To report such an outbreak at a regional teaching hospital in southern Taiwan.

METHODS

From October to December 2010, ertapenem-resistant Enterobacter cloacae were identified from urine cultures of 15 patients who had undergone ureteroscopy prior to the infection. Three batches of surveillance cultures were obtained from the environmental objects and healthcare workers related to the procedures. Pulsed-field gel electrophoresis (PFGE) was used for bacterial typing. Antimicrobial susceptibility was assessed by disc diffusion and E-test methods. Polymerase chain reaction and sequencing were used to analyse β-lactamase genes.

FINDINGS

A total of 70 specimens were obtained during the first surveillance operation. One ertapenem-resistant E. cloacae was isolated from a ureteroscope. Although the disinfection protocols for ureteroscopes were revised and implemented, seven additional UTI cases were identified thereafter. The pathogen was identified from two subsequent surveillance cultures and was not eliminated until ethylene oxide sterilization was added to the disinfection protocol. PFGE revealed that all 15 isolates from the patients and the three isolates from the ureteroscope shared a common pattern with minor variance. Most isolates were resistant to gentamicin, levofloxacin, ceftriaxone, ceftazidime, and ertapenem. All isolates were susceptible to amikacin, imipenem, and meropenem. SHV-12 and IMP-8 genes were simultaneously identified in 16 of the 18 isolates.

CONCLUSION

The outbreak of ertapenem-resistant E. cloacae was caused by a contaminated ureteroscope and was terminated by the implementation of a revised disinfection protocol for ureteroscopes.

Assessing the risk of disease transmission to patients when there is a failure to follow recommended disinfection and sterilization guidelines

Medical devices that enter body tissues should be sterile, whereas devices that contact mucous membranes should be high-level disinfected between patients. Failure to ensure proper cleaning and sterilization or disinfection may lead to patient-to-patient transmission of pathogens. This paper describes a protocol that can guide an institution in managing potential disinfection and sterilization failures.

Current status of cleaning and disinfection for gastrointestinal endoscopy in China: a survey of 122 endoscopy units

BACKGROUND

Adequate compliance with the existing guidelines for cleaning and disinfection of gastrointestinal endoscopes and accessories is necessary to obtain high-level disinfection and prevent pathogen transmission.

AIM

To investigate cleaning and disinfection practice in China.

METHODS

A questionnaire with 21 questions concerning gastrointestinal endoscopy reprocessing was sent by e-mail to 189 endoscopy units in China.

RESULTS

One hundred and twenty-two (80.39%) of the 189 units responded. Compared with the low-workload units (<5000 procedures/year), the high-workload units (≥5000 procedures/year) had a significantly higher number of gastrointestinal endoscopes (25.8 ± 3.6 vs. 4.7 ± 1.8, p < 0.01) and the higher possessing rate of automated endoscope reprocessors (43.9% vs. 3.1%, p<0.01). Glutaraldehyde was the most commonly employed disinfectant (88.5%) in all the units. In 23/122 (18.8%) units, the exposure time to glutaraldehyde was <45 min in the case of infectious disease patients. Eighty-six of 122 (70.5%) units reused disposable materials, of which 21/86 (24.4%) reused disposable forceps and disposable polypectomy hooks, and 2/86 (1.6%) reused disposable injection needles intermittently.

CONCLUSION

Although gastrointestinal endoscopy has developed rapidly in China in the past decade, there is still room for improvement in the practice of endoscopy reprocessing, especially in middle-sized and small cities.

Reprocessing in digestive endoscopy units in Lombardy: results of a regional survey

BACKGROUND AND AIM

Inadequate disinfection of endoscopes and associated instrumentation can result in transmission of infections to patients. The aim of this study is to assess cleaning and disinfection practice in gastrointestinal endoscopy units in public and private institutions in the Lombardy region.

METHODS

We drafted a questionnaire which we e-mailed to all gastrointestinal centers in Lombardy.

RESULTS

A total of 79 centers responded (77%). All endoscopy units perform manual cleaning before disinfection. Automated endoscope reprocessors are available in 84.4% of the centers. Glutaraldehyde-based disinfectants are the most common employed (67% of centers). The time of exposure to the disinfectant is of 10 min in only 9.8% of the centers. The majority of endoscopy units modify their disinfection procedures in the case of infectious disease patients. In 59% of centers disposable material is only used once. In 37% of the endoscopy units instruments are dried with propanol.

CONCLUSIONS

The data collected suggest that cleaning and disinfection practices have improved in recent years, and that there is a good compliance with standard guidelines. There is still room for improvement in equipment, disinfection protocols, and traceability of instruments in order to improve safety for patients and staff.

Inconsistencies in endoscope-reprocessing and infection-control guidelines: the importance of endoscope drying

INTRODUCTION

Endoscope reprocessing is a multi-stepped process that renders a contaminated endoscope safe for reuse. Its steps include meticulous cleaning, complete immersion in a liquid chemical sterilant (LCS) or disinfectant to achieve high-level disinfection (or "liquid sterilization"), water rinsing, and proper handling and storage. Surveys and reports indicate that not all health-care facilities dry their endoscopes after reprocessing. Endoscope drying can be easily, quickly, and inexpensively achieved by flushing the endoscope's internal channels, and wiping its external surfaces, with 70-90% ethyl or isopropyl alcohol, to facilitate drying after reprocessing, followed by compressed or forced air.

METHODS

The medical literature was reviewed to evaluate the importance of endoscope drying to the prevention of disease transmission. Several national and international endoscope-reprocessing and infection-control guidelines and a public health advisory were also reviewed and compared for consistency and to evaluate the emphasis each places on endoscope drying. If a guideline recommends endoscope drying, this study clarified whether this step is recommended after reprocessing throughout the day (i.e., between patient procedures), before storage, or both. These guidelines were also reviewed to determine whether any of them recommend reprocessing endoscopes before the first patient of the day.

RESULTS

This review identified several published reports and clinical studies that demonstrate the significant contribution of endoscope drying to the prevention of disease transmission. This review also identified significant differences and inconsistencies regarding the emphasis different published guidelines and a public health advisory place on endoscope drying. Some guidelines recommend drying the endoscope after completion of every reprocessing cycle, both throughout the day and before storage, while others deemphasize its importance and recommend endoscope drying only before storage, if at all. Instead of recommending endoscope drying before storage, some guidelines recommend reprocessing endoscopes before the first patient of the day.

DISCUSSION AND CONCLUSION

The finding that several guidelines are inconsistent with one another and that some are remiss and fail to recommend endoscope drying is of concern. Endoscope drying is as important to the prevention of nosocomial infection as cleaning and high-level disinfection (or "liquid sterilization"). Whereas wet or inadequately dried endoscopes pose an increased risk of contamination and have been associated with transmission of waterborne microorganisms and nosocomial infection, thoroughly dried (and properly cleaned and high-level disinfected) endoscopes have not been linked to nosocomial infection. Moreover, inconsistent guidelines can confuse reprocessing staff members and result in noncompliance, variations in the standard of care, and ineffective reprocessing. To minimize the risk of disease transmission and nosocomial infection, modification and revision of guidelines are recommended as required to be consistent with one another and to unconditionally recommend endoscope drying after completion of every reprocessing cycle, both between patient procedures and before storage, no matter the label claim of the LCS or disinfectant, the label claim of the automated reprocessing system, or the microbial quality of the rinse water. According to the medical literature, adoption of this recommendation may reduce the importance of not only monitoring the microbial quality of the rinse water, but also reprocessing endoscopes before the first patient of the day, both of which can be costly practices that a few guidelines recommend.

Current issues in endoscope reprocessing and infection control during gastrointestinal endoscopy

The purpose of this article is to review the evidence regarding transmission of infection during gastrointestinal endoscopy, factors important in endoscope reprocessing and infection control, areas to focus on to improve compliance, and recent developments and advances in the field.

Endoscope disinfection using chlorine dioxide in an automated washer-disinfector

Although 2% glutaraldehyde is often the first-line agent for endoscopic disinfection, its adverse reactions are common among staff and it is less effective against certain mycobacteria and spore-bearing bacteria. Chlorine dioxide is a possible alternative and an automated washer-disinfector fitted with this agent is currently available. This study was conducted to evaluate the effectiveness of chlorine dioxide in endoscopic disinfection after upper gastrointestinal examination. In vitro microbicidal properties of chlorine dioxide solutions were examined at high (600 ppm) and low (30 ppm) concentrations against various microbes including Pseudomonas aeruginosa, Helicobacter pylori, Mycobacterium avium-intracellulare and Bacillus subtilis in the presence or absence of bovine serum albumin (BSA). Immediately following endoscopic procedures and after application to the automated reprocessor incorporating chlorine dioxide at 30 ppm for 5 min, endoscopic contamination with infectious agents, blood, H. pylori ureA gene DNA and HCV-RNA was assessed by cultivation, sensitive test tape, polymerase chain reaction (PCR) and reverse transcriptase-PCR analysis, respectively. Chlorine dioxide at 30 ppm has equivalent microbicidal activity against most microbes and faster antimicrobial effects on M. avium-intracellulare and B. subtilis compared with 2% glutaraldehyde, but contamination with BSA affected the microbicidal properties of chlorine dioxide. Endoscopic contamination with microbes, blood and bacterial DNA was eliminated after application of the automated reprocessor/chlorine dioxide system. Thus, chlorine dioxide is a potential alternative to glutaraldehyde. The use of automated reprocessors with compatibility to chlorine dioxide, coupled with thorough pre-cleaning, can offer effective, faster and less problematic endoscopic disinfection.

Unusual implication of biopsy forceps in outbreaks of Pseudomonas aeruginosa infections and pseudo-infections related to bronchoscopy

Between January and April 2003, a sudden increase in positive respiratory tract specimens for Pseudomonas aeruginosa was observed in an intensive care unit of the University Teaching Hospital of Montpellier, France. Most of the strains were cultured from bronchoalveolar lavage fluid samples, suggesting that bronchoscopic procedures could be implicated. The relationships between isolates were investigated by antibiotyping and pulsed-field gel electrophoresis. Both phenotypic and molecular markers allowed identification of two consecutive nosocomial outbreaks of respiratory infections related to two different bronchoscopes. These two outbreaks implicated nine and seven patients, respectively. Four of these 16 patients had true infections and recovered with antibiotic therapy. Inspection of both bronchoscopes revealed a damaged internal channel caused by defective biopsy forceps. These defects led to improper cleaning and disinfection of the bronchoscopes despite adherence to all current reprocessing procedures. The two outbreaks were controlled after replacing the inner channels of the bronchoscopes and switching from use of re-usable to disposable biopsy forceps. These outbreaks emphasize the need to establish surveillance procedures for detecting contamination of bronchoscopes, and the importance of recording each endoscopic procedure to facilitate further investigations if needed.