A review published in 1993 investigated the transmission of infection caused by flexible gastrointestinal (GI) endoscopes and by broncoscopes.¹ The culmination of events reported from 1966 to July 1992 found nearly 400 infections had been transmitted by these instruments.

In the GI endoscopy-related infections, Salmonella species and Pseudomonas aeruginosa (P. aeruginosa) were repeatedly identified as the causative pathogens. Mycobacterium tuberculosis, atypical mycobacteria, and P. aeruginosa were the culprits of the 90 identified bronchoscopy-related infections.

The clinical spectrum of the infections calculated in this review ranged from asymptomatic colonization to death. The researchers clearly note that improper cleaning and disinfection, contamination by automatic washers, and the inability to thoroughly clean the scopes due to their complex channel and valve systems were the reasons for infection transmission.

To prevent endoscopic transmission of infections, recommended disinfection guidelines must be followed, the effectiveness of automatic washers must be carefully monitored, and improvements in endoscope design are needed to facilitate effective cleaning and disinfection, the authors warn.

This thought hasnt changed much since 1993, but still more must be done in the vast world of healthcare to ensure these steps are being taken properly.

For example, more than 1 million GI endoscopic procedures are performed each year in the United States,² and as Rachel L. Stricof, MT, MPH, an epidemiologist at the New York State Department of Health and member of the Society for Healthcare Epidemiology of America (SHEA) points out, endoscopic procedures are increasingly being performed in private practice settings and clinics.

These environments offer their own set of challenges. For example, a large problem in this type of setting, as Stricof notes, is that there are many of these individual or freestanding clinics and offices that do not have a centralized sterile processing department (SPD) as a part of the overall facility.

Thus, proper practices in the care of the scopes may not be carried out.

Depending upon the state regulations, private practice settings and clinics may not need to be accredited or regulated by an outside or governmental agency and therefore, the reprocessing methods and systems may not undergo the same degree of evaluation, oversight, and quality assurance as a hospital or accredited facility, she contends. Regardless of where a procedure is performed; standard, validated, and effective methods are critical to ensure patient safety.

A review from researchers out of Ohio State University, Columbus, reviewed 70 outbreaks of infection related to endoscopy and bronchoscopy. ³ What is interesting to note from this review is that the researchers point to inadequate decontamination practices as the leading cause of contamination of the scopes (equipment malfunction was No. 2).

A haunting reality relating to this topic was documented when a group of researchers at Johns Hopkins distributed a survey to practicing bronchoscopists concerning their individual knowledge on the recommended practices encircling the proper protocols for these instruments.4 The questions on the survey directly addressed infection control issues related to bronchoscopy and the specific reprocessing recommendations for the instrument.

The surveys were completed by medical directors of bronchoscopy suites (26 percent) and by attending bronchoscopists (74 percent) who had graduated from medical school a median of 22 years prior and had performed a median of 19 procedures per month.

Shockingly, an astounding 65 percent of respondents and 55 percent of directors were not familiar with national reprocessing recommendations and nearly 40 percent did not know the approach to reprocessing at their own institution.

Challenges Aplenty

William A. Rutala, PhD, MPH, professor in the division of infectious diseases of the Department of Medicine at the University of North Carolina, Chapel Hill, points out in a 2004 study² that, Flexible endoscopes, by virtue of the site of use, have a high bioburden of microorganisms after use.

He adds that the failure to employ appropriate cleaning, disinfection, and sterilization practices of endoscopes is the main culprit responsible for multiple nosocomial outbreaks and serious, sometimes life-threatening infections. Rutala further points out that a protocol that describes the meticulous manual cleaning process, the appropriate training and evaluation of personnel, and a solid quality assurance program should be adopted and enforced by each unit performing endoscopic reprocessing.

Stricof agrees with Rutala that systems must be in place to ensure equipment is reprocessed properly. She adds that the device also must be handled properly after reprocessing to ensure it does not become contaminated in storage or between procedures.

Stricof further notes, that the inherent complexity of the instruments with their long, narrow lumens, flexible joints, multiple channels, openings, and valves, pose significant reprocessing challenges.

Reprocessing requires meticulous cleaning and high-level disinfection or sterilization of internal channels, external surfaces, openings (ports), valves, and caps, she says, adding, that it is unfortunate that the current design of endoscopes are not able to withstand the heat and pressure associated with steam sterilization, which she says is the most safe and reliable method of sterilization.

Nyla Skee Japp, RN, PhD, ACSP, CSPDM, of Phoenix-based Infection Control Specialties and nurse manager of the central sterile processing department at Banner Desert Medical Center in Mesa, Ariz., agrees that endoscopes are concerning because of their complex structure. Cleaning, according to Japp, is the most vital part in the process because if the scope is not thoroughly cleaned it will not be disinfected or sterilized.

I think too many times because of the hurried environment of getting more patients done, shortcuts may be taken to save that precious commodity of time, she explains. The problem then of scrupulously hand cleaning with a brush and using copious rinsing of water to ensure biofilm is completely removed may not occur. Both rigid endoscopes and flexible endoscopes require special cleaning. Flexible scopes are very difficult to clean because of their numerous small channels and length. Having the right-sized cleaning brush is vital to cleaning the lumen. If the channels are not clean, it will not be disinfected or sterilized.

She continues, Because most scopes are unable to be put in the ultrasonic cleaner, bioburden absolutely can become an issue with the scope. There are six basic steps in cleaning scopes: pre-cleaning, leak testing, cleaning, disinfection/ sterilization, drying, and storing. All removal parts must be removed, soaked in enzymatic solution to begin the digestion of the protein, and then scrubbed with a brush to remove all the debris. All accessible channels must be brushed to remove particulate matter. Inspect what you have cleaned to ensure the scope is clean. All steps must be done in the correct order, and any shortcuts will lead to scopes not being properly cleaned thus, build-up of bioburden.

The other challenges with endoscopes are cleaning the accessory parts, she continues. The items that can be disassembled for cleaning must be disassembled for cleaning, disinfection, and sterilization. The accessory items that have internal moving parts pose a great challenge in preparation for sterilization. I also have concerns regarding the inspection of the flexible scopes ensuring that close attention is paid to the seams and body joints, she adds.

Bradley Catalone, PhD, senior manager of infection control at Olympus America Inc. points out that when it comes to cleaning and disinfection, everyone in the hospital, ambulatory surgery center (ASC) or private GI practice has an important role in ensuring that endoscopes are reprocessed and maintained.

He points out that the majority of improper endoscope reprocessing occurs during the manual cleaning stage. Cleaning is the most critical reprocessing step, removing more than 99 percent of the bioburden from the endoscope. Failure to properly clean endoscopes has considerable consequences for both the patient and the healthcare provider.

First and foremost, inadequate endoscope cleaning jeopardizes patient safety. Although pathogen transmission in endoscopy is rare, documented cases of pathogen transmission have been invariably linked to breaches in reprocessing, with the majority being associated with a failure to properly clean the endoscope according to manufacturers instructions. He offers the more common reprocessing deficiencies in the steps below.


  • Failure to reprocess unique channels (example: elevator wire or auxiliary water channel) 

  • Not using the proper adapter to reprocess the air/water channels 

  • Transporting the endoscope without using a closed container or with sharp accessories 

  • Delayed reprocessing, especially for procedures performed at night or on weekends 

Leak Testing 

  • Use of damaged water resistant cap

  • Overlooking pressurization of scope prior to immersion Incomplete angulation of the distal tip in all directions during leak test 

  • Not following the manufacturers guidelines for reprocessing a damaged scope 

Manual Cleaning 

  • Neglecting to dilute the detergent according to manufacturers specifications 

  • Reuse of disposable brushes and other accessories 

  • Failure to use manufacturers recommended cleaning adapters 

  • Use of damaged or improperly reprocessed cleaning adapters 

  • Using a sink or basin of insufficient dimensions 

  • High level disinfectant Inadequately testing the minimum effective concentration of high-level disinfectant according to manufacturers instructions (i.e., every cycle) 

  • Failure to maintain a log of high-level disinfectant use and endoscope reprocessing 


  • Oversight in removing all valves and caps when storing the endoscope 

  • Neglecting to ensure that scopes are hung with all locks in the free position 

  • Crowded and unsecured scope storage areas 

Scopes need to be leak tested after every procedure, and the condition of the water resistant cap must be checked with every use, he adds. Immediate bedside cleaning reduces the possibility of damage such as clogged nozzles and channels.

Other important factors Catalone mentions is proper handling and regular inspections. In general, be conscious of any surface with which a scope comes in contact, as it can be a potential source of insertion tube punctures and damage, he warns. Perform functionality and visual inspections of endoscopes prior to every procedure. An inspection of the functional aspects of the scope prior to each procedure will help to ensure that the scope is ready to be safely used.

Stephen M. Kovach, BS, director of education with Healthmark Industries readdresses Japps comments on the hurried pace in which those in healthcare work. He recognizes that the time factor for cleaning and inspection is challenging to the staff reprocessing these items. To do it right takes time, he says. Some items have to be taken apart and flushed; staff has to take the time to let the various cleaning solutions work; enzymes need time to break down the target soil; cleaning solution products are all different staff tend to use the lower time limit for soaking (when) at least five minutes is needed for soaking. Next is the verification of these items that they are clean, which can not be done visually.

Having a quality process in place to monitor the process is so important. This has to be done to help ensure items are safe to be used. Each medical facility has to work with infection control, risk management, and their staff to put in a program that works for their medical facility.

Education is Critical

In a nutshell, the first line of defense for these scope-related infections is the proper education and training of central sterile (CS)/SPD personnel. (They) need to know and understand the manufacturers step-by-step recommendations, Stricof offers. Japp agrees, adding that CS/SPD staff must be trained to follow the manufacturer guidelines for cleaning, disinfection, and sterilization. In-services should be given initially by the manufacturer then reviewed with staff annually, with new staff in orientation, and as determined by the manager.

Kovach says education and training should be provided from the manufacturer of the equipment, from the manufacturer of the cleaning solution used, of the scope cleaning system used, and of the scope disinfection/sterilization equipment used. Moreover, any repair service that is used should review reports on a monthly basis of the facilitys repairs of scopes and instruments to help in reducing repairs and to ensure that equipment is being used in the correct manner.

Technology is dynamic and changing all the time. That is why all staff including physicians need to be updated (at least yearly, and all training should also be documented). New products are being introduced that help staff verify their process and should be used as help in the training. Also, hands-on training of the scopes and instruments and using various processes to test both equipment and staff for cleaning is important.

Doing it Right

Stricof warns that it is often difficult to implicate a scope on the basis of a single infection. Likewise, it may also prove challenging to isolate a single culprit scope in a cluster of infections. But, if a scope-related infection is suspected, infection control, clinical, and reprocessing staff should be notified at once and an investigation should be initiated. The steps involved in an investigation are multiple and may occur simultaneously, she says.

She adds that verifying the diagnosis, determining if others have been affected, attempting to identify the cause and instituting control measures to prevent further occurrences, conducting tests to determine if the source of the problem has been identified correctly, and ensuring that prevention measures are working, all are the beginning steps to take.

If possible, identify the explicit scope, evaluate reprocessing steps and determine if there has been a problem with the specific device or methods of reprocessing, she offers.

One good example of Stricofs advice can be found in the lessons learned from an outbreak that occurred at a New York Hospital.5 Over a three-month period in 1998, 18 patients were identified to have contracted imipenem-resistant P. aeruginosa (IRPA) following bronchoscopy procedures. All strains except one were found to be greater than 95 percent related.

The investigation included a review of clinical data, environmental cultures, the molecular analysis of all IRPA isolates, and special observation of the disinfection practices of the bronchoscopes.

The researchers found that a new automatic endoscope reprocessor (AER) for all endoscopes and bronchoscopes had just recently been installed. Inspection of the bronchoscope sterilization cycles revealed that incorrect connectors that join the bronchoscope suction channel to the processor were unknowingly being used; resulting in the obstruction of peracetic acid flow through the bronchoscope lumen. It is interesting to note that no malfunction warning was given and spore strips remained negative.

The researchers concluded that the similarity of diverse connectors contributed to the factors responsible for the outbreak. After appropriate connections were implemented, there was no further bronchoscope contamination. The hospital has since standardized its connectors for various scopes and automated processors.

Some type of monitoring and or testing should be done, Kovach asserts. I have seen a lot over the years both as a user and manufacturer. Many of the errors I see can be prevented with a good quality improvement program. The quality program relies upon both the staff observations and monitoring the complete process. Using product that helps you solve concerns like cleaning verification products that if used can help prevent concerns before they happen. Just waiting to have the government state you must test and monitor is not the answer.

Catalone also offers the following tips to help prevent incidents of infection:

  • Read, understand, and follow the manufacturers instructions and the guidance provided by professional organizations like ASGE, SGNA, etc.

  • Join and participate in organizations such as the SGNA or APIC 

  • Stay current by subscribing to and reading infection control-related magazines, literature, and journals 

  • Talk with co-workers and friends from other facilities; challenge the device manufacturers sales representatives, field engineers, and clinical specialists with questions and issues 

Overall, failure to properly clean endoscopes produces a myriad of avoidable consequences that drain resources from effective healthcare delivery and improving patient outcomes, Catalone notes. 


1. Spach DH, et al. Transmission of infection by gastrointestinal endoscopy and bronchoscopy. Ann Intern Med 1993: 118:117-128.

2. Rutala WA, Weber DJ. Reprocessing endoscopes: United States perspective. J Hosp Infect. 2004 Apr;56 Suppl 2:S27-39.

3. Seoane-Vazquez E, et. al. Exogenous endoscopy-related infections, pseudo-infections, and toxic reactions: clinical and economic burden. Curr Med Res Opin. 2006 Oct;22(10):2007-21.

4. Srinivasan A, et. al. Bronchoscope reprocessing and infection prevention and control: bronchoscopy-specific guidelines are needed. Chest. 2004 Jan;125(1):307-14.

5. Sorin M, et al. Nosocomial transmission of imipenem-resistant Pseudomonas aeruginosa following bronchoscopy associated with improper connection to the Steris System 1 processor. Infect Control Hosp Epidemiol. 2001 Jul;22(7):409-13.