Gastroenterological Endoscopy. Группа авторов

and 23 outbreaks during ERCP (89 patients).²² Most identified outbreaks, involving 85% or more of patient cases, were attributed to deficiencies in cleaning and disinfection of endoscopes or water bottles, or contaminated AERs.¹⁵ The predominant organisms involved were Helicobacter pylori, Salmonella, hepatitis C virus, and Pseudomonas aeruginosa. Undoubtedly, publication and other public reporting mechanisms significantly underrepresent the likely occurrences of disease transmission during endoscopy. More recently, numerous outbreaks involving patient-to-patient transmission of multidrug-resistant organisms (MDROs) have been reported to occur following ERCP, as discussed in the following.

      6.3.1 Transmission by Endoscopes with Elevators

      Multiple cases of P. aeruginosa cholangitis after ERCP were recog nized many years ago.²³ They were attributed to insufficient drying of the endoscope at the end of the procedure day, and largely eradicated by use of an alcohol flush and forced air drying between procedures. Multiple episodes of duodenoscope transmission of carbapenem-resistant enterobacteriaceae (CRE) or other MDROs were published or publicly acknowledged in the 2013–2015 time frame, some having occurred up to 5 years earlier.^{24,25,26,27,28,29} As of early 2016, approximately 25 outbreaks have infected at least 250 patients, with at least 20 deaths.³⁰ When closely evaluated, most centers appear to have been adhering to HLD guidelines, without shortfalls in practice or equipment. The risk appears to be related to the challenge of cleaning and disinfection in tight crevices surrounding the elevator mechanism and its actuation cable. Several studies suggest further risk from wear and degradation with routine use.^29,31 The U.S. FDA and others have provided a series of mandatory, advisable, and future interventions to prevent such episodes in the future (

Table 6.4).^15,23,32,33 The role of routine servicing based on time or procedure numbers remains unknown. Limited case reports and culture studies suggest similar risk of persistent contamination after reprocessing of echoendoscopes.^34,35

      6.3.2 Failure or Breach in Reprocessing

      On occasion, endoscopy unit staff identify inappropriate or incomplete reprocessing for one or more endoscopes. Breaches in reprocessing are not uncommon; however, transmission of an infectious agent is far less so, due to variations in prevalence and infectivity of significant organisms, immune clearance of the gut, and the degree to which the lapse in reprocessing reduced the likely clearance of pathogens. An organized approach is useful for addressing the shortfall in reprocessing. Steps include investigating the risk to patients, communicating with appropriate local and regulatory groups, and potentially undertaking a notification and call-back program for exposed patients. Several algorithms have been described to accomplish the necessary elements.^36,37 Both the scope of breaches in reprocessing and nuance regarding the nature of the breach may influence the institutions’ decisions regarding patient notification. In the current era, most guidance advises informing patients and serologic or culture testing are selectively based on the perceived risk.

Table 6.4 Means toward reducing risk in complex instruments

1. Ensuring quality of endoscope reprocessing

• Optimal training, oversight, and competency evaluation of existing processes

• Endoscope culture after HLD and quarantine until return of negative cultures

• Selective endoscope culture following use in MDRO (+) patient and quarantine until return of negative cultures

• Surveillance culture of endoscopes intermittently for quality assurance of HLD process

• Routine or intermittent surveillance testing of bioburden (e.g., ATP) for QA of washing processes before HLD

2. Enhanced or alternative approaches to reprocessing

• Routine per procedure ETO sterilization following HLD

• Selective or intermittent ETO sterilization, for suspicion of biofilm (culture positivity) or following use in patient carrying MDRO

• Routine use of double cycles of washing + HLD after each procedure (wash→ HLD→ wash→ HLD)

• “Liquid sterilization” using peracetic acid

3. Identification of high-risk patients to guide use of alternative endoscope reprocessing

• Routine surveillance for CRE and/or other MDROs (via PCR or culture and sensitivity) by anal swab in all patients undergoing ERCP → with subsequent intensified/alternative reprocessing if positive

4. Potential new technologies

• Alternative designs for endoscopes that harbor elevators or other complex functions:

• Enhanced access for cleaning—removable tips

• Tolerance to high-temperature autoclaving

• Single-use disposable components

• New modalities for precleaning and/or washing

• New low-temperature sterilization technologies

Abbreviations: ATP, adenosine triphosphate; CRE, carbapenem-resistant enterobacteriaceae; ERCP, endoscopic retrograde cholangiopancreatography; ETO, ethylene oxide; HLD, high-level disinfection; MDRO, multidrug-resistant organism; PCR, polymerase chain reaction; QA, quality assurance.

Source: Adapted from Petersen,^23 Rutala and Weber,^15 and FDA.^32,33

      6.3.3 Unusual Organisms

      Almost all contaminating organisms are efficiently eradicated if they can be adequately exposed to standard means of cleaning (by mechanical action and detergents) and HLD employing appropriate germicides. In contrast, prions are transmissible infectious agents that are highly resistant to commonly employed methods of HLD and sterilization. They are the etiologic agent of a variety of extremely rare, and lethal, spongiform encephalopathies, which predominantly infect tissues of the central nervous system, such as Creutzfeldt–Jacob disease (CJD), kuru, and others. While prions can be inactivated by more intense application of nonstandard cleaning agents and sterilization parameters, many guidelines advise against reuse of medical devices that are exposed to nervous system tissues of patients with CJD.³⁸

      6.4 Design and Oversight of Reprocessing Facilities

      The recent clusters of infection attributed to persistent contamination despite apparent adherence to current reprocessing guidelines have prompted renewed emphasis on reprocessing facility design, unit leadership, and training and supervision of reprocessing staff. All of these issues are assessed during accreditation evaluation. Facility design is more standardized than in the past. Designs routinely incorporate expectations for sufficient air exchanges to avoid exposure of staff to reprocessing fumes and chemicals, and floor plans that enable instrument flow from dirty to clean, with avoidance of crossover to dirty areas often carefully evaluated.

      Quality performance in most settings is highly dependent on the tenor and expectations set by the leadership and administrative staff of the organization. Recent infection outbreaks have prompted the U.S. FDA and accreditation agencies to further emphasize these issues. Training, competency testing, repeated continuing oversight of performance, and documentation of both administrative and technical steps are all highlighted in recent FDA and Centers for Disease Control and Prevention (CDC) guidance.^7,39

      References

      [1] Petersen BT. Gaining perspective on reprocessing of GI endoscopes. Gastrointest Endosc. 1999; 50(2):287–291

      [2] Petersen BT, Chennat J, Cohen J, et al. Multisociety guideline on reprocessing flexible GI endoscopes: 2016 update. Gastrointest Endosc. 2017; 85(2):282–294

      [3] Gastroenterologic Society of Australia. Clinical Update: Infection Control in Clinical Endoscopy. 3rd ed. Melbourne: Gastroenterologic Society of Australia; 2010

      [4] Beilenhoff U, Neumann CS, Rey JF, et al; ESGE Guidelines Committee. European Society of . Gastrointestinal Endoscopy. European Society of Gastroenterology