Transmission of pathogens, including Carbapenem Resistant Enterobacteriaceae (CRE), by inadequately reprocessed flexible endoscopes is well documented in scientific literature as well as popular media and is recognized as a serious risk to patients. Healthcare providers and administrators in many roles, Gastroenterology, Infection Prevention, Sterile Processing, Surgical Services, Executive Management, Risk Management, and more, are wrestling with difficult questions—How confident am I that my facility has adequate processes in place? What are our quality control measures? Are there steps we need to take to minimize the risk of CRE or other pathogen transmission from inadequately reprocessed duodenoscopes or other similarly complex flexible GI endoscopes?
The “scope” of the issue
What is clear right now is that there is no single root cause and no single “fix” for the challenges of endoscope reprocessing. Studies show that even with the best of intentions, current reprocessing guidelines are not always followed to the letter. A study published online Aug 5 in AJIC1 provides evidence that contamination remains even when observers document that each and every step is completed properly. Not only that, but this study showed that contamination remains even after cleaning (or multiple rounds of cleaning and disinfection) on colonoscopes and gastroscopes, and thus is a concern not limited to the duodenoscopes that are currently the focus of concern.
Even the oft-cited microbiological culturing is only a small piece of a complex microbiological puzzle, according to Alex Kallen of the CDC in the latest from USA Today.
“A negative [duodenoscope] culture should not be relied on to rule out a scope as a source of an outbreak,” says Kallen, the CDC official. “There doesn’t necessarily have to be a positive duodenoscope culture; it is more of a preponderance of evidence. … If you have other epidemiological links, the scope might well be the source.”1
Based on what we know today and solutions that are currently available, there are two steps that facilities can take to help mitigate risk and safeguard their patients.
We know that adequate cleaning, physical removal of clinical soil/bioburden, is imperative to effectively perform subsequent reprocessing steps. But how do you know whether an endoscope has been adequately cleaned? With the publication of AAMI ST91:2015 Flexible and semi-rigid endoscope processing in healthcare facilities, (recognized as a consensus standard by the U.S. FDA on 8/14/2015), new guidance is available related to cleaning verification. Section 12.4 – Verification and Monitoring of the Cleaning Process recommends that healthcare facilities:
- Implement a defined, documented process for verifying the efficacy of manual cleaning–this should include the types and number of scopes tested and the frequency of testing
- Routine monitoring should include visual inspection AND another method of cleaning verification (common methods available to healthcare facilities include ATP bioluminescence, protein, hemoglobin, carbohydrate)
- Use rapid cleaning indicators to monitor cleaning efficacy—weekly, preferably daily for each endoscope processed
Developing a quality control program that includes routine endoscope monitoring with a rapid cleaning indicator will generate immediately actionable data. 3M™ Clean-Trace™ ATP Monitoring System is a rapid cleaning monitor validated against established manual cleaning benchmarks (protein, hemoglobin, and bioburden) for endoscope channels. In 30 seconds, the Clean-Trace System is able to quantify the cleanliness of a surface or lumen sample using Adenosine triphosphate (ATP) bioluminescence. With the integrated software, you can focus your quality improvement efforts for cleaning processes, for example:
- Pinpoint individual endoscopes that are consistently failing to meet recommended thresholds.
- Use generated data to identify potential cleaning process issues, such as missed or inadequate bedside flushes, or the need to modify cleaning solutions.
- Document your quality assurance process and provide proof of adequately cleaned endoscopes to consistently deliver highest standard of care.
The case for sterilization
One recent CRE outbreak investigation revealed no lapses in reprocessing steps associated with cleaning and high level disinfection (HLD), leading investigators to the conclusion that the duodenoscopes had the “potential to remain contaminated with pathogenic bacteria even after recommended reprocessing is performed.”2
This and other evidence combine to cast doubt on the adequacy of high level disinfection for at least some types of flexible endoscopes. Despite the critical nature of the distinction between HLD and sterilization, there continues to be a great deal of confusion about, and misuse of, the two terms in discussions of endoscope reprocessing. Disinfection is defined by ANSI/AAMI ST58:2013 as a “process that kills pathogenic and other microorganisms by physical or chemical means. Disinfection destroys most recognized pathogenic microorganisms but not necessarily all microbial forms, such as bacterial spores.”
Today, the most common biocidal practice used for duodenoscopes and other flexible endoscopes is high level disinfection (HLD) using a liquid chemical disinfecting agent. Faster device reprocessing time and lower cost are the primary benefits of HLD.
In contrast, sterilization is defined as “a validated process used to render product free from viable microorganisms” (from ISO/TS 11139:2006 Sterilization of health care products — Vocabulary). Terminal sterilization and liquid chemical sterilization processes are required to kill all types of microorganisms including bacterial spores. Terminal sterilization cycles also include an extra margin of safety, referred to as the “overkill” process, which includes the time it takes to kill all spores and then doubles that time to create a sterilization cycle for a large margin of safety. A liquid chemical sterilization process does not have this margin of safety.
Terminal sterilization with ethylene oxide is validated and described in the IFUs for many models of endoscopes, including high-risk duodenoscopes. Ethylene Oxide (EO) is known to be gentle on instruments and is highly penetrating, making it ideal for complex devices such as long lumen flexible endoscopes. Modern EO sterilizers are engineered for safety and comply with occupational safety requirements.
The 3M™ Steri-Vac™ Sterilizer/Aerator GS series was introduced earlier this year. Though outdated concerns and misinformation continue to circulate, here are some facts about EO sterilization with the Steri-Vac Sterilizer GS series. It is:
- Safe for staff and the environment:
- Proven to be safe for staff when installed and operated according to instructions
- Engineered safety features including 100% EO single-dose cartridges and cycles run entirely under vacuum and aeration performed in locked chamber
- Available with a 3M™ Abator that converts EO exhaust into CO2 and water vapor with a conversion efficiency of 99+% – virtually eliminating emissions of EO to the environment
- Highly efficacious—as a gas, it can penetrate medical devices with complex components including long, narrow lumens, with no restrictions on the length or inner diameter of endoscope channels
- A traditional sterilization method that has been relied upon by healthcare, medical device, government and other industries for decades
As you know, the FDA, industry, professional organizations, and reprocessing experts are working diligently to understand the issues contributing to endoscope associated infections. In May 2015, a U.S. FDA panel convened to hear commentary on the topic. Dr. William Rutala, an internationally known expert in Infection Control and Epidemiology, presented the panel with a strong recommendation.
“To protect the public health we (FDA, industry, professional organizations) must shift endoscope reprocessing from HLD to sterilization. FDA should mandate that duodenoscopes (preferably all GI scopes) used in healthcare facilities be sterile by 2018.”4
As an outcome of that meeting, at the beginning of August, the FDA released FDA Safety Communication: Supplemental Measures to Enhance Duodenoscope Reprocessing which includes the use of Ethylene Oxide Sterilization as a listed supplemental endoscope processing measure. Although evidence is still being assembled, multiple facilities dealing with CRE outbreaks have reported adding Ethylene Oxide (EO) sterilization to their endoscope reprocessing protocol, and following the change, no further cases of CRE were identified (Illinois, Pennsylvania, California, Wisconsin3,5-7). Facilities with EO sterilizers can take action now. Facilities without on-site EO sterilizers should assess the feasibility of purchasing new equipment or consider outsourced EO sterilization.
Moving from HLD to sterilization is no small undertaking. The EO sterilization cycle time is much longer than the brief exposure time required for HLD. Additional endoscopes inventory may be required. When working with your leadership team, there are issues of risk assessment and cost that will require hard questions and diligent effort. Yet, your patients are counting on you to advocate on their behalf, to ensure they receive the highest standard of care, the care you would want for your own family.
Undoubtedly, this issue will continue to be discussed, studied, and debated because there are no easy answers. More data will help uncover the most effective modifications to current guidelines and design innovation may someday offer redesigned endoscopes or biofilm resistant surfaces. Until then, what we do know, and what should guide us, is the knowledge that doing nothing is NOT an option.
To learn more about this topic, download the white paper, “An Approach to Improving the Quality and Consistency of Flexible GI Endoscope Reprocessing.”
- Ofstead CL, Wetzler HP, Doyle EM, et al. Persistent contamination on colonoscopes and gastroscopes detected by biologic cultures and rapid indicators despite reprocessing performed in accordance with guidelines. AJIC 2015;43(8):794-801. doi:10.1016/j.ajic.2015.03.003.
- Eisler, Peter. Deadly infections from medical scopes go unreported, raising health risks. USA Today. August 5, 2015. http://www.usatoday.com/story/news/2015/08/05/duodenoscope-infections-not-reported/29988165/. Accessed August 25, 2015.
- Epstein L, Hunter JC, Arwady MA, et al. New Delhi Metallo-β-Lactamase–Producing Carbapenem-Resistant Escherichia coli Associated with Exposure to Duodenoscopes. JAMA. 2014;312(14):1447-1455. doi:10.1001/jama.2014.12720.
- Rutala WA. ERCP Scope: A Need to Shift from Disinfection to Sterilization? Presented at: Meeting of the U.S. FDA Medical Devices Advisory Committee Gastroenterology-Urology Devices Panel; May 14-15, 2015; Washington, D.C.
- McCool S, Muto CA, Querry A, et al. High Level Disinfection (HLD) Failure in Gastrointestinal Scopes with Elevator Channels – Is it Time to Switch to Ethylene Oxide (ETO) Sterilization? Poster presented at: IDWeek; October 8-12, 2014; Philadelphia, PA.
- UCLA statement on notification of patients regarding endoscopic procedures. UCLA Health Web site. https://www.uclahealth.org/news/ucla-statement-on-notification-of-patients-regarding-endoscopic-procedures Updated February 19, 2015. Accessed August 25, 2015.
- Smith ZL, Oh YS, Saeian K, et al. Transmission of carbapenem-resistant Enterobacteriaceae during ERCP: time to revisit the current reprocessing guidelines. Gastrointestinal Endoscopy. 2014;81(4):1041-1045. doi:10.1016/j.gie.2014.11.006.