Device-Related Infections: Patient-Ready Bronchoscopes Found to be Contaminated Despite Cleaning and Disinfection

By Kelly M. Pyrek

As you may recall several years ago, a significant number of infections associated with contaminated bronchoscopes in a short time prompted the Food and Drug Administration (FDA) to issue a Safety Communication about microbial transmission and infection associated with bronchoscopes. The agency urged the strict adherence to sterile processing guidelines and pointed out that inadequate cleaning may result in the failure of high-level disinfection (HLD) or sterilization. The FDA also recommended that bronchoscopes with signs of damage be repaired or replaced, a recommendation from the American College of Chest Physicians and American Association for Bronchology to visually inspect bronchoscopes during reprocessing.

As Ofstead, Quick, et al. (2018) emphasize, "Implications of the FDA’s recommendations could be profound if bronchoscope durability is similar to other endoscopes, as researchers recently reported that 100 percent of ureteroscopes had defects after a mean of 19 uses, and 100 percent of gastrointestinal endoscopes developed defects within a few months."

Research published in the journal Chest and presented at the recent annual meeting of the Association of Professionals in Infection Control and Epidemiology (APIC) indicates that even when proper cleaning and disinfection protocols are followed, patient-ready reusable, flexible bronchoscopes were contaminated and damaged, and present a serious threat to patient safety.

As Ofstead, Quick, et al. (2018) assert, "Infections have been linked to inadequately-reprocessed flexible bronchoscopes, and recent investigations determined that pathogen transmission occurred even when bronchoscope cleaning and disinfection practices aligned with current guidelines." Their multi-site, prospective study involved direct observation of reprocessing methods for flexible bronchoscopes, multifaceted evaluations performed after manual cleaning and after high-level disinfection, and assessments of storage conditions. Visual inspections of ports and channels were performed using lighted magnification and borescopes. Contamination was detected using microbial cultures and tests for protein, hemoglobin, and adenosine triphosphate. Researchers assessed reprocessing practices, and storage cabinet cleanliness was evaluated by visual inspection and adenosine triphosphate tests.

The researchers examined 24 clinically used bronchoscopes, obtaining samples from consecutive bronchoscopes used in procedures during site visits. Site personnel performed reprocessing in accordance with their institutional practices. (Protocols for effectively reprocessing bronchoscopes are complex and include bedside pre-cleaning, leak testing, manual cleaning, and sterilization or high-level disinfection (HLD) followed by drying.) Microbial culture samples were harvested from ports and distal ends using sterile swabs moistened with sterile, deionized water. Biochemical tests for organic residue were conducted onsite in accordance with manufacturer instructions for use for detecting adenosine triphosphate (ATP), protein and hemoglobin, and luminometers measured ATP levels in samples from ports, insertion tubes, distal ends and channel effluent; hemoglobin and protein tests were performed using spectrophotometers. After bronchoscopes were sampled, re-reprocessed, and stored overnight, visual examinations were performed using a camera and borescopes; photographs were taken at predetermined locations and whenever unique irregularities were observed.

After manual cleaning, the researchers report that 100 percent of bronchoscopes had residual contamination. Protein was detected in samples from 100 percent of bronchoscopes post-manual cleaning and 100 percent post-HLD. Microbial growth was found in 14 (58 percent) fully reprocessed bronchoscopes, including mold, Stenotrophomonas maltophilia, and Escherichia coli/Shigella spp. Hemoglobin was detected on one manually-cleaned bronchoscope and no post-HLD bronchoscopes or negative controls. Hemoglobin levels in positive controls ranged from 0-3 µg/mL. Post-manual cleaning, the median ATP level was 31 RLU (range 17-170 RLU) for surfaces and 26 RLU (range 4-220 RLU) for effluent. Post-HLD, the median ATP level was 20 RLU (range 12-166 RLUs) for surfaces and 8 RLU (range 3-26 RLU) for effluent.

Visible irregularities were observed in 100 percent of bronchoscopes, including retained fluid; brown, red, or oily residue; scratches; damaged insertion tubes and distal ends; and filamentous debris in channels. Reprocessing practices were substandard at two of three sites visited.

As Ofstead, Quick, et al. (2018) observe, "The source of contamination found on bronchoscopes at study sites is unknown, and there are several potential conduits for contamination. Direct exposure to pathogens during procedures is common given the patient populations, and reprocessing quality was poor in two of the three sites. Damaged bronchoscopes were in use at all sites, and previous studies have shown that damaged endoscope surfaces may foster the formation of biofilm. Results of tests done on a new bronchoscope at Site C in this study suggest contaminants were introduced to the bronchoscope during manual cleaning, as microbial growth and high levels of protein were detected after initial cleaning (before any clinical use). Cross-contamination from dirty environmental surfaces could explain the presence of gastrointestinal bacteria in bronchoscopes, as all sites reprocessed bronchoscopes in AERs also used for gastrointestinal endoscopes. Site B had intentionally disabled the cleaning cycle on their AERs to save time (approximately 20 minutes per cycle). This presumably had a negative impact on reprocessing effectiveness and possibly fostered the accumulation of biofilm in their AERs. The study protocol did not include performing additional tests needed to assess the impact of this breach, and further research will be necessary to determine the prevalence and impact of disabling AER cycles … Results of tests done on a new bronchoscope at Site C in this study suggest contaminants were introduced to the bronchoscope during manual cleaning, as microbial growth and high levels of protein were detected after its initial cleaning. Storage conditions could also have contaminated reprocessed bronchoscopes, as visual inspections and ATP tests determined that storage cabinets were not clean. Other researchers recently reported that similar bacteria were detected on settle plates placed inside storage cabinets and in samples taken from fully reprocessed duodenoscopes stored in the cabinets for 24 to 72 hours. Guidelines currently recommend cleaning storage cabinets regularly to reduce the risk of re-contaminating reprocessed endoscopes. Additionally, nursing staff at Sites B and C were observed handling and transporting patient-ready bronchoscopes with bare hands, potentially exposing bronchoscopes to contaminants."

Speaking at the most recent APIC annual meeting and presenting the results of the study published in Chest, Cori Ofstead, MSPH, principal of Ofstead & Associates, Inc., reminded the audience, "We have been looking at the effectiveness of reprocessing for about 10 years now; we have done studies in nine states and we have looked at the reprocessing of more than 900 scopes and we have looked at them from head to toe." She added, "When you think about bronchoscopy and you ponder whether it deserves a lot of attention when it comes to reprocessing effectively, we have to think about what we are using them for and who we are using them on. They are used for procedures that are routine and often very quick, such as assisting with intubation or removing a foreign object, and for diagnostic procedures, very often doing biopsies, and it becomes very important that we don't have any contaminated scopes. We have done a lot of work with GI scopes and I thought colonoscopes would be as bad as it gets in terms of gooey things and then we started doing traces and watching procedures and the bronchoscope procedures are really messy; you can do a colonoscopy and have no blood, but the bronchoscopes are messy and often they will be draining pus or fluid and secretions, resecting tumors strictures or performing ablation-type procedures and placing stents or valves and doing advanced procedures with these scopes."

In her presentation at APIC, Ofstead emphasized the continuance of breaches in protocols. "In theory and accordance with the IFUs, bronchoscopes are supposed to be reprocessed starting immediately after use; and the first thing that is supposed to happen is a bedside pre-cleaning as soon as that bronchoscope comes out of the patient's body," Ofstead says. "When that's done, they should be transported to a reprocessing area where they would undergo a leak test and then they would be thoroughly cleaned and rinsed off. After that, they are supposed to get a visual inspection to make sure that you got all the gunk off, and that is supposed to be performed with lighted magnification. The guidelines from AAMI and AORN now recommend that there also be biological testing for cleaning verification, so because the scope is black and you can't see inside of it, you must do something to make sure that the cleaning you did in the dark, so to speak, actually worked. Once you verify that it is clean, and if it's not clean, you clean it again, then it would either be sterilized or high-level disinfected and dried before storage. In some of the guidelines it is also specified that it should get a visual inspection right before use. I caution people that we often boil down the steps into this short, compact list that sounds easy but what we know when we go in to perform audits there are numerous steps when following the guidelines and depending on the scope, there might be 100 to 140 steps they must do and they generally must do them in an order that is specific. So, it's a lot to remember."

Kovaleva (2015) reminds us of the risks associated with bronchoscopy; she writes, "The exogenous microorganisms most frequently associated with transmission of infection during bronchoscopy are Pseudomonas aeruginosa and mycobacteria. These microorganisms can be transmitted from previous patients or contaminated reprocessing equipment by contaminated endoscopes or accessory equipment. Exogenous infection should be prevented by strict endoscope disinfection procedures. During the period 1970-2012, 48 outbreaks of exogenous bronchoscopy-related infections and cross-contaminations involving 198 infected patients were reported in the literature. Several outbreaks of bronchoscopy-related transmission of multidrug-resistant P. aeruginosa and carbapenemase-producing Klebsiella pneumoniae have been published during the past few years."

She points to the need for scrupulous reprocessing of bronchoscopes: " Accurate reprocessing of flexible bronchoscopes is a multistep procedure involving cleaning followed by sterilization or high-level disinfection (HLD) with further rinsing and drying before storage. Most flexible bronchoscopes belong to semi-critical devices which contact mucous membranes during use and have a moderate degree of infection risk if contaminated at the time of use. They should receive at least HLD resulting in elimination of all vegetative bacteria, mycobacteria, fungi, and viruses, except for small numbers of bacterial spores. Flexible bronchoscopes used for therapeutic purposes in sterile body cavities belong to critical devices and should be sterilized after each procedure to eliminate all forms of microbiological life, including bacterial spores. Due to their material composition, most flexible bronchoscopes cannot be steam sterilized. They tolerate ethylene oxide and hydrogen peroxide plasma sterilization, which are expensive, can destroy mechanical properties of instruments and are not preferred by most institutions. Accurate endoscope drying and storage are crucial, whereas a humid environment facilitates microbial growth during storage. The final drying steps greatly reduce the risk of remaining pathogens as well as the possibility of recontamination of the endoscope by waterborne microorganisms such as Pseudomonas spp. and Acinetobacter spp. According to the literature, endoscopes stay bacterium free after prolonged storage if an adequate drying procedure is applied. The most common factor associated with microbial transmission is inadequate cleaning and disinfection of flexible bronchoscopes (60 percent of outbreaks). These outbreaks were related to inadequate manual cleaning and brushing, use of contaminated endoscope accessories, use of inappropriate disinfectants with low and intermediate potency, and resistance of microorganisms to disinfectants. Use of the contaminated or defective automated endoscope reprocessors (AERs) and contaminated water for rinsing of the endoscope channels after disinfection were associated with 33 percent of outbreaks. Insufficient drying and inadequate storage resulted in 29 percent of outbreaks, design limitations and defective bronchoscopes in 14 percent of outbreaks. It is important that contamination of flexible bronchoscopes was detected in 65 percent of outbreaks.

Kovaleva (2015) adds, "Modern bronchoscopes contain multiple channels and ports which are difficult to clean and disinfect and allow for the collection of organic material and the forming of biofilms. A biofilm is an assemblage of microbial cells attached to a surface and enclosed in a matrix of exopolymeric substances. Biofilms are extremely difficult to remove, show increased resistance to disinfectants and antibiotics and can result in failure of reprocessing of endoscopes and outbreaks of endoscopy-related infections. Two outbreaks of bronchoscopy-related infection and cross-contamination of P. aeruginosa, Mycobacterium chelonae and Methylobacterium mesophilicum involving 28 patients were attributed to contaminated AERs with the presence of biofilm deposits on the internal plumbing."

Kovaleva (2015) acknowledges that routine microbiological testing for endoscopes and AERs remains a controversial issue in many guidelines: "Microbiological surveillance of endoscope reprocessing has been recommended by several medical specialist organizations but there are no standards for the frequency of testing intervals of surveillance cultures. It is appropriate to trace contaminations of endoscopes and to prevent contaminations and infections in patients after endoscopic procedures. The use of environmental endoscope culturing is a rapid and simple method to monitor the effectiveness of standard reprocessing procedures. Contaminated bronchoscopes have been linked to many outbreaks of device-related nosocomial infections. The true incidence of bronchoscopy-related infections is unknown because of inadequate surveillance or no surveillance at all. Endoscopy-related infections can cause serious harm and can give rise to concerns over these procedures by physicians and patients. A continuous search for ways to improve the disinfection process and to construct such endoscopes that the risk of biofilm formation will be reduced, remains warranted."

"There is a grand debate going on about whether we should be high-level disinfecting versus sterilizing all scopes and certainly bronchoscopes are at the top of the list of how we should be doing things," Ofstead remarked during her presentation at APIC. "Almost wherever you go, people are doing HLD for bronchoscopes and I think it is important to start thinking about this with critically. My stance is that this should be classified as a critical device and should be sterilized."

As Ofstead, Quick, et al. (2018) emphasize, "Damaged and contaminated bronchoscopes were in use at all sites. Inadequate reprocessing practices may have contributed to bioburden found on bronchoscopes. However, even when guidelines were followed, high-level disinfection was not effective. A shift toward the use of sterilized bronchoscopes is recommended. In the meantime, quality management programs and updated reprocessing guidelines are needed."

Ofstead continues, "We know that contamination accumulates over time and creates biofilm. We know this happens under the best circumstances and there have been numerous reprocessing failures associated with bronchoscopy. We know all the steps that are supposed to be done, just don't happen much of the time. And because the patients undergoing bronchoscopy are extremely high risk, this becomes more problematic than using a dirty colonoscope, for example, because the colon can handle exposure to pathogens. But the patients receiving bronchoscopy often are critically ill, immunosuppressed, and unfortunately we know there are a whole lot of outbreaks and colonization associated with contaminated bronchoscopes."

Ofstead pointed to a recent study in which Sarmand, et al. (2018) found that following bronchoscopy, seven colonized patients underwent a change in their flora. "I think patients undergoing bronchoscopy are at an extremely high risk of infection and if we are using a scope and we are not sterilizing it, we are introducing pathogens into their lungs. In our study, we found that not only were scopes not sterile, but they weren't even clean -- patient-ready scopes were not clean. And they were not free of pathogens, and I think IPs must get in there because if these are being handled by the GI suite, that isn't good enough. We need to have an IP presence there, we need to get those quality assurance programs in place, and think about how we can move toward sterilization."

Ofstead emphasized the importance of optimizing system-wide policies that move toward the use of sterilized bronchoscopes. Additionally, she urged APIC attendees to address the following issues that may be contributing to risk:
- The co-mingling of GI endoscopes and bronchoscopes
- The use of lubricants that cannot be removed
- Water-quality issues in the reprocessing department
- Inadequate bedside pre-cleaning
- Delayed reprocessing
- Reprocessing protocol for evenings and weekends


Kovaleva J. Transmission of infection by flexible bronchoscopy. Sept. 2, 2015. Accessible at:

Ofstead CL, Quick MR, Wetzler HP, Eiland JE, Heymann OL, Sonetti DA and Ferguson S. Effectiveness of reprocessing for flexible bronchoscopes and endobronchial ultrasound bronchoscopes. Chest. May 2018.

Ofstead CL, Wetzler HP, Heymann OL, Johnson EA, Eiland JE, Shaw MJ. Longitudinal assessment of reprocessing effectiveness for colonoscopes and gastroscopes: Results of visual inspections, biochemical markers, and microbial cultures. Am J Infect Control. 2017;45(2):e26-e33.