WGO Guideline—Endoscope Disinfection Update

Abstract

The WGO Guideline “Endoscope Disinfection” is intended for use by health providers and professionals who are involved in the use, cleaning, and maintenance of endoscopes and aims to support national societies, official bodies and individual endoscopy departments in developing local standards and protocols for reprocessing endoscopes. This updated Endoscope Disinfection Guideline addresses the recent outbreaks of multi-drug resistant organisms after endoscopy and proposes measures to reduce the risks of these outbreaks occurring. The recommendations are based on the consensus findings of an international multidisciplinary working group with expertise in microbiology, including biofilms, endoscope reprocessing, nursing, and gastroenterology, and with broad experience in developing national and international reprocessing guidelines. - First Name Country 1. Tony Speer (Chair) Australia 2. Michelle Alfa Canada 3. Alistair Cowen Australia 4. Dianne Jones Australia 5. Karen Vickery Australia 6. Helen Griffiths UK 7. Roque Sáenz Chile 8. Anton LeMair Netherlands GUIDELINES OR STANDARDS Reprocessing instructions are often called guidelines but are, in fact, a technical standard that sets out the minimum acceptable practice for reprocessing to deliver high-level disinfection of endoscopes. The distinction between the 2 terms is important. Medical guidelines usually address a narrow clinical question using population-based data, often results of randomized trials in a specific population, to guide the care of an individual patient.1 Standards are broader in the application and set out specifications and procedures designed to ensure products, services, and systems are safe, reliable, and consistently perform the way they were intended. The supporting evidence for a standard is based on science, technology, and experience rather than clinical trials. The standards governing reprocessing are based on the science of cleaning, disinfection, drying, and microbiology, and recommendations are supported by measurements of efficacy in models with artificial soils and/or a known inoculum of bacteria. The implementation of the appropriate standards for reprocessing should follow the general principles of good manufacturing practice (GMP). GMP is a set of regulations, codes, and guidelines for a manufacturing process, in this case reprocessing an endoscope to produce a high-level disinfected endoscope. These regulations cover both performances of reprocessing and quality control of the process. GMP is recognized worldwide for the control and management of manufacturing and quality control testing of pharmaceutical products and has evolved over the last 60 years in response to multiple well-publicized problems in the pharmaceutical industry.2 While the terms guidelines and standards are both used to describe instructions for endoscope reprocessing3,4 these instructions are best considered as a technical standard. General Principles in Endoscope Reprocessing The most important step in endoscope reprocessing is scrupulous manual cleaning before disinfection. Disinfection will fail if the cleaning has been inadequate.5–7 Manual cleaning must be undertaken by a person familiar with the structure of the endoscope and trained in cleaning techniques. Cleaning should begin immediately after the endoscope is used so that biological material does not dry and harden. Appropriate detergents and cleaning equipment should be used; in particular appropriate diameter brushes should be used for each channel. Cleaning should be followed by thorough rinsing to ensure all debris and detergents are removed before disinfection. Manual Cleaning Pre-Cleaning—Immediately after each procedure, with the endoscope still attached to the light source, the insertion tube should be wiped with a lint-free disposable cloth and the distal tip placed in a low foaming medical grade detergent solution and detergent aspirated through all channels, including the suction/biopsy channel. The air/water channels should be flushed with detergent, and then all channels flushed, including the jet channel if present, with water, then air, as per the manufacturer’s instructions. A specific valve may be required to flush the air/water channels with detergent. The endoscope should be removed from the light source and transported to the cleaning area in a closed container that avoids environmental contamination from drip or spill, and that clearly indicates that the endoscope within is contaminated. It is essential that the endoscope is not allowed to dry before further cleaning as this will make the removal of organic matter difficult or impossible. Endoscopes should be processed without delay within 30 minutes. Leak testing should be performed to check the integrity of all channels before further processing. All the valves and buttons should be removed and leak testing performed as per the manufacturer’s instructions. Buttons and valves should be brushed and disinfected, paying particular attention to internal surfaces and high-level disinfection or sterilization according to the original equipment manufacturer’s instructions. The endoscope should be placed in a detergent solution in a sink in the “dirty” section of the decontamination area and the outer surface washed. A low foaming medical grade detergent should be used at the appropriate dilution according to the manufacturer’s instructions. All accessible sections of the suction biopsy channel should be brushed according to the manufacturer's instructions for use, and each channel should be brushed until all debris is removed. The tip and handles and clean valve seats should be brushed and then cleaning adapters fitted and channels flushed with fresh detergent for the product specified time. The endoscope should be rinsed by draining the detergent from the sink, rinsing the outer surface with cold running tap water, then filling the sink with tap water and purging the channels with tap water using the cleaning adapters following the manufacturer’s instructions. The channels should be purged with air to remove rinse water. Disinfection High-level disinfection is performed in an Automatic Flexible Endoscope Reprocessor (AFER) that should comply with the relevant national standard or be approved by the Food and Drug Administration (FDA). The AFER may or may not have an automated cleaning and disinfection cycle. All connectors should be specifically designed for each endoscope model. All channels should be connected at the start and end of a cycle. The detachable components, including the air/water and suction valves, can be steam sterilized or reprocessed with the endoscope if the ability of the AFER to clean and/or disinfect these detachable components is validated by the AFER manufacturer. After high-level disinfection, the endoscope is rinsed in the AFER with bacteria-free water produced by sub-micron filters. Water quality should be checked regularly. Manual high-level disinfection is another option that is effective when performed by well-trained, dedicated reprocessing staff supplied with appropriate personal protective equipment. The endoscope should be immersed in disinfectant, and all channels are filled with disinfectant solution, and the buttons and valves should be immersed in the disinfectant. The instrument should be soaked for the required time at the required temperature and concentration as specified by the disinfectant manufacturer. All channels should be purged with air to remove the disinfectant, the exterior of the endoscope rinsed and the channels flushed with bacteria-free water, with the volume required for the specific disinfectant used, to remove any traces of disinfectant. Drying Endoscopes should be dried after each procedure by purging the water from the channels with compressed air, then flushing the channels with alcohol, followed by forced air drying. Alcohol flush facilitates drying and is a useful adjunct to disinfection because of its bactericidal effects.8 The use of alcohol may not be permitted in some countries (France, UK) because of concerns about variant Creutzfeldt-Jakob disease. The endoscope should be stored in a forced air-drying cabinet to supplement drying. If an endoscope is used infrequently, it is reasonable to store it separately hanging vertically in a purpose-built cabinet as opposed to a forced air storage/drying cabinet, and then reprocess the endoscope before the next patient use. Endoscopes should be dried completely before hanging. Accessories The water bottle should be changed after each endoscopy session and steam sterilized. The water bottle should be filled with sterile water immediately before use. Documentation All essential steps of endoscope reprocessing should be documented for quality assurance and for patient tracing if necessary. OUTBREAKS The recent reports of outbreaks of multi-drug resistant organisms (MDROs) after endoscopy, particularly carbapenem-producing Enterobacteriacae (CPE), have focused critical attention on the efficacy and safety of reprocessing protocols. CPE has become established in the hospital environment and may cause clinical infections with substantial morbidity and mortality because of their antibiotic resistance. Outbreaks of CPE after endoscopy have been reported in several countries often after ERCP9 but also following bronchoscopy,10 gastroscopy,11–13, and flexible cystoscopy.14,15 Often, microbiological surveillance identifies a single source for an outbreak of MDROs that can be traced to a culprit endoscope that has transmitted genetically similar bacteria on multiple occasions despite reprocessing. MDROs may also be transmitted sporadically by endoscopes without a single source being identified by genetic studies. In case-control studies of hospital inpatients, a recent endoscopy, including gastroscopy, bronchoscopy, and ERCP, was a significant risk factor for acquiring MDRO colonization/infection.13,16–18. The risk of transmitting infection at endoscopy is underestimated; a risk of 1 in 1.8 million is often quoted.19 The correlation of an infection with a previous endoscopy is difficult to establish confidently, and if established, is not always reported to authorities and is seldom published.20,21 The paucity of reports from less developed countries is likely to be due to failure of detection and reporting rather than a true absence. Cultures of patient-ready endoscopes provide a better estimate of the problem.22 Cultures of endoscopes performed immediately before a procedure and for routine microbiological surveillance suggest that at least 2-4% of endoscopes, including gastroscopes, colonoscopes, and duodenoscopes are transmitting bacteria.23–26 Transmission of antibiotic-sensitive enteric bacteria at gastroscopy and colonoscopy rarely causes clinical illness; however, transmitted bacteria may colonize the patient.27,28 The recent outbreaks were only identified because of the distinctive features of the CPE, the antibiotic resistance.29 CPE is acting as a marker of transmission, and the emergence of CPE has exposed long-standing flaws in endoscope reprocessing.30 Many of the problems associated with recent outbreaks are well recognized problems from the past, including breaches of cleaning and disinfection protocols, often failure to dry before storage, and occult endoscope defects that compromise cleanability. However, there are also outbreaks where cleaning and disinfection were performed according to guidelines, and the manufacturer can find no fault in the endoscope. Recent publications have found that current reprocessing standards do not provide a reasonable level of safety and effectiveness.31–34 In response to outbreaks, the FDA’s May 2015 Advisory Panel35 encouraged facilities to consider supplemental measures, including double reprocessing between patients, ethylene oxide sterilization, or the use of a liquid sterilant processing system. About 15 months after these recommendations were made, a survey of providers performing ERCP in the USA found 63% of centers performed double disinfection and 12% ethylene oxide sterilization.36 However, these additional measures are expensive and time-consuming, and ethylene oxide sterilization is not readily available.33 Subsequent to this advice, a randomized trial comparing the 3 reprocessing protocols, standard high-level disinfection, double high-level disinfection, and ethylene oxide sterilization, concluded that these enhanced disinfection methods did not provide additional protection against contamination.33 Another randomized trial found double high-level disinfection was no better than standard high-level disinfection.37 It is increasingly recognized that biofilms on endoscopes compromise cleaning and disinfection.34,38,39 The conditions reported as causes of outbreaks facilitate biofilm formation and growth; these include inadequate cleaning, inadequate drying, occult endoscope defects, including channel damage and breaches of reprocessing protocols. Biofilm prevention and control are core problems in reprocessing that are addressed in these guidelines The changes proposed can be broadly summarized as follows: Cleaning—carefully follow the manufacturers’ updated reprocessing instructions specific for each model of endoscope. Drying—improved drying with an alcohol flush and 10 minutes of forced air after each procedure. Endoscopes should be stored in a forced-air drying cabinet. Occult endoscope defects—routine endoscope maintenance to identify and repair defects. Routine channel replacement to reduce the prevalence of occult defects and maintain a smooth cleanable channel surface. Breaches of reprocessing protocols—Establish a multidisciplinary committee to develop and implement reprocessing protocols and to perform quality control of training, the process and outcomes. NEW RECOMMENDATIONS Recommended Changes to Reprocessing and Storage Prompt attention to cleaning, disinfection, and complete drying reduces the growth of established biofilm and prevents bacteria from forming new biofilm (Table 1). TABLE 1 - Specific Recommendations for Reprocessing and Storage Activity Recommendations Precleaning Precleaning must be carried out IMMEDIATELY after use. Cleaning Cleaning (manual or using an AFER with an FDA or National approved cleaning cycle) must be carried out PROMPTLY* within 30 minutes after precleaning. Always follow the most up to date manufacturer’s specific instructions for cleaning for each model of endoscope. Disinfection After manual cleaning of the endoscope, machine or manual high-level disinfection must be undertaken promptly. Endoscopes should be thoroughly rinsed with bacteria-free water after disinfection. Alcohol flush and forced-air drying After disinfection by any means the endoscope must have prompt alcohol flush and forced-air for 10 minutes and in an approved forced air storage/drying Drying cabinet Endoscopes must in approved forced air-drying until next patient use. surveillance surveillance of endoscopes and at appropriate to local conditions and endoscopes for maintenance and consider the instrument channel 2 years or according to as by the endoscope are considered in these means within 30 endoscope may be used on another patient after the forced-air drying but it must be placed the cabinet if not immediately used for another patient section on Drying indicates flexible endoscope Recommended Changes for 2 TABLE 2 - Specific Recommendations for ERCP of procedures the of ERCP procedures performed is to this clinical staff and dedicated staff reprocessing duodenoscopes who are of and have undertaken specific in the particular problems associated with cleaning, and endoscope for surveillance surveillance of duodenoscopes protocols that include from the distal with surveillance with organisms of should be for there is an staff appropriate risk of MDRO in their of duodenoscopes for instrument channels and at least on as by the endoscope should be to using the and that has been validated by indicates multi-drug resistant Endoscope Drying It is critical that drying is performed following manual or AFER of AFER manufacturer endoscopes should have a alcohol flush and forced-air channel drying for 10 minutes. drying endoscopes should be to an approved endoscope forced air storage/drying cabinet, and air drying This should until the endoscope is used or the has should comply with the relevant National or with the Storage for Endoscopes If the can be used for another patient procedure after the forced air drying or before the drying in the cabinet is to CPE Transmission in the CPE is through the the of is often through of or bacteria are found in hospital and also found in and an outbreak of an MDRO after ERCP found the culprit MDRO in and in the water used to rinse the before for prevention and control of CPE surveillance and and environmental should implement national and local infection control multi-drug resistant guidelines. that with reduces of (Table TABLE 3 - Recommendations to CPE Transmission Recommendations CPE of the CPE of CPE that known CPE are to the endoscopy at the CPE or at who are to be should be last on the and in from with use of a or a and procedure after the endoscopy procedure as per specific protocols for cleaning of standards and should comply with the national standards to the risks of from in or of from control procedures The emergence of CPE is another to follow standard infection control procedures including and the use of appropriate personal protective equipment and for each should provide and of with and environmental cleaning and CPE indicates carbapenem-producing AFER Water quality should be appropriate for the water should be according to an established and the internal sub-micron as per the manufacturer’s instructions for use. GUIDELINES recommendations for reprocessing are set out in international and national Recent guidelines from and the have been updated to the and the manufacturer’s These guidelines will the of national and guidelines. In all health are according to in low and countries have increasingly focused on The of endoscopy can be from the of the services, the and the of The emergence of CPE has the risk of infections after endoscopy and the of inadequate reprocessing. The of an infection with CPE are substantial in both developed and low and The risk of transmitting CPE on the prevalence of CPE in for endoscopy quality of reprocessing and of repair of the endoscopes. and hospital should the local prevalence of CPE to implement appropriate risk must the principles of reprocessing and be of the risk to when there is failure of endoscope should to an previous of maintenance and and that are or have a previous should be reported that inadequate to 2 duodenoscopes to an outbreak and the of endoscope and Endoscope reprocessing should be by a multidisciplinary committee reprocessing is on by The of is best by a multidisciplinary committee including infection control and and most The committee should use a process to and the of a quality management for both the and the process as by the Standards and The recent of the of and of and quality for endoscope and should be developed in with relevant The committee must be up to date with recent publications and internal to ensure reprocessing with recent recommendations from and In low and there may be a of and a in trained guidelines should be to specific and quality control should start with measures as of process and with guidelines should be over surveillance that is expensive and If are a local multidisciplinary committee should the and make a based on a risk by local to consider include to a with and the for a trial of a outbreaks of MDROs after endoscopy, may become and no clinical only to develop infections to months with mortality reported as as a single of CPE is transmitted from 1 endoscope on multiple occasions despite reprocessing. This is best by a biofilm on the endoscope bacteria from cleaning and disinfection and acting as a for of Biofilm In the of an outbreak of a following bronchoscopy, it was considered that biofilm forming in difficult to endoscopy channels to this A the surfaces of endoscope channels with and the of biofilm often in surface studies have also found biofilm on endoscope and on culprit endoscopes in reports of Biofilm is a of bacteria attached to a surface and to each by an in a biofilm have than bacteria of the biofilms are often resistant to used at reprocessing CPE are in 1 by of standard a safety for these However, biofilm the of the multiple of and biofilm are difficult for the disinfectant to of do not the bacteria within in biofilm that in defects on endoscope channel surfaces are also by organic debris and difficult to with standard reprocessing based on from models using artificial soils and bacteria to be using models bacteria in biofilm or Biofilm attached to the surface of an endoscope channel as a of and bacteria in biofilms can their and be transmitted to and a of facilitate biofilm growth and of bacteria. The of biofilm growth and the of complete drying after reprocessing has been in the evidence indicates of endoscopes still in channels after AFER alcohol a drying and in a the endoscope of particularly the channels storage, must be a in endoscopes cleaning and provide a for biofilms to defects may be identified by including defects in the and and the Occult defects that do not with endoscope are difficult to identify without the endoscope or using as a of channels in working endoscopes has found and defects on the channel of channel surfaces biofilm in these that culprit endoscopes have found occult defects, including and routine and maintenance reduce the use of endoscopes with defects that compromise Endoscope and national guidelines routine are difficult to clean and In to the as the of for ERCP, and the performed also to the risk of and infection from bacteria transmitted the procedure. The of contamination of as by surveillance is similar to the of contamination of and patient and the performed are in the of outbreaks after The risks of outbreaks are best addressed by specific changes to cleaning and disinfection of duodenoscopes as well as to reprocessing protocols for all endoscopes. The manufacturers’ updated cleaning protocols are an important in reprocessing. of a quality assurance of found that implementation of the new cleaning protocols the of However, manufacturers’ surveillance studies have found with important Drying The reprocessing step of drying has often been or carried out and is to A survey in the of reprocessing in endoscopy performing found that of the centers did not comply with the and did not use forced air to dry are with another and do not always the for Recent studies have found in up to of endoscope channels after reprocessing and drying, drying guidelines to Alfa and in a that if duodenoscopes were after reprocessing there was growth of and Drying for 10 minutes with forced air this in all duodenoscopes of an alcohol flush followed by forced air drying outbreaks of infections after ERCP in the recent studies have that alcohol flush followed by 10 minutes of forced air drying was effective than alcohol flush followed by a time of forced air endoscopes should be stored in a drying cabinet and evidence that of flexible endoscopes facilitates drying, the for and protection from environmental This is supported by a of surveillance of patient-ready endoscopes, including gastroscopes, colonoscopes, and found that the of drying the risk of endoscope In a a forced-air drying cabinet dried endoscopes and growth with a standard The science of reprocessing is including clinical and randomized trials undertaken in response to the publications of outbreaks of CPE, is being Endoscope to endoscope and new reprocessing instructions. drying and cleaning are in the are updated of reprocessing guidelines in response to the of These and recent guidelines a multidisciplinary committee with a of and expertise to new as it is and and reprocessing guidelines that are appropriate to the and patient reprocessing is to patient safety in

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