Bronchoscopy-related outbreaks and pseudo-outbreaks: A systematic review.

OBJECTIVE: To identify and report the pathogens and sources of contamination associated with bronchoscopy-related outbreaks and pseudo-outbreaks. DESIGN: Systematic review. SETTING: Inpatient and outpatient outbreaks and pseudo-outbreaks after bronchoscopy. METHODS: PubMed/Medline databases were searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, using the search terms "bronchoscopy," "outbreak," and "pseudo-outbreak" from inception until December 31, 2022. From eligible publications, data were extracted regarding the type of event, pathogen involved, and source of contamination. Pearson correlation was used to identify correlations between variables. RESULTS: In total, 74 studies describing 23 outbreaks and 52 pseudo-outbreaks were included in this review. The major pathogens identified in these studies were Pseudomonas aeruginosa, Mycobacterium tuberculosis, nontuberculous mycobacteria (NTM), Klebsiella pneumoniae, Serratia marcescens, Stenotrophomonas maltophilia, Legionella pneumophila, and fungi. The primary sources of contamination were the use of contaminated water or contaminated topical anesthetics, dysfunction and contamination of bronchoscopes or automatic endoscope reprocessors, and inadequate disinfection of the bronchoscopes following procedures. Correlations were identified between primary bronchoscope defects and the identification of P. aeruginosa (r = 0.351; P = .002) and K. pneumoniae (r = 0.346; P = .002), and between the presence of a contaminated water source and NTM (r = 0.331; P = .004) or L. pneumophila (r = 0.280; P = .015). CONCLUSIONS: Continued vigilance in bronchoscopy disinfection practices remains essential because outbreaks and pseudo-outbreaks continue to pose a significant risk to patient care, emphasizing the importance of stringent disinfection and quality control measures.

Adoption of Improved Reprocessing Decreased Microbiological Non-Compliance for Bronchoscopes.

BACKGROUND: In the past few decades, the inadequate reprocessing of bronchoscopes has been associated with several serious outbreaks caused by multidrug-resistant microorganisms. In this study we evaluated the improvement in the quality of reprocessing in a Bronchoscopy Unit (BU), after the introduction of a new procedure. METHODS: In 2019, observational and clinical audits were conducted in the BU. After the introduction of an improved procedure in 2020, a microbiological surveillance plan was implemented in 2021. RESULTS: In 2019, 13 of 22 bronchoscopes (59%) resulted as non-compliant, 18% as high concern organisms (HCO) and 36.4% as high microbial count (≥100 CFU/all channels) and HCO. The most frequent microorganisms were Staphylococcus aureus (38.5%) and NDM-producing Klebsiella pneumoniae (15.4%). The bronchoscopes were stored inside their transport cases, which in some cases were found to be contaminated by the same strains isolated on the bronchoscopes (Enterobacter gergoviae and Vibrio alginolyticus). In 2021, all 31 bronchoscopes were sampled at least three times and 13/99 (13.1%) resulted as non-compliant, mostly K. pneumoniae (4.04%). Contamination level increases weakly in bronchoscopes in use for more than 14 years (R = 0.32). CONCLUSIONS: The adoption of an improved reprocessing procedure decreased the non-compliance of bronchoscopes, increasing the quality of the process and patient safety.

Both microbiological surveillance and audit of procedures improve reprocessing of flexible bronchoscopes and patient safety.

BACKGROUND: Microbiological surveillance of bronchoscopes and automatic endoscope reprocessors (AERs)/washer disinfectors as a quality control measure is controversial. Experts also are divided on the infection risks associated with bronchoscopic procedures. OBJECTIVE: We evaluated the impact of routine microbiological surveillance and audits of cleaning/disinfection practices on contamination rates of reprocessed bronchoscopes. DESIGN: Audits were conducted of reprocessing procedures and microbiological surveillance on all flexible bronchoscopes used from January 2007 to June 2020 at a teaching hospital in France. Contamination rates per year were calculated and analyzed using a Poisson regression model. The risk factors for microbiological contamination were analyzed using a multivariable logistical regression model. RESULTS: In total, 478 microbiological tests were conducted on 91 different bronchoscopes and 57 on AERs. The rate of bronchoscope contamination significantly decreased between 2007 and 2020, varying from 30.2 to 0% (P < .0001). Multivariate analysis confirmed that retesting after a previous contaminated test was significantly associated with higher risk of bronchoscope contamination (OR, 2.58; P = .015). This finding was explained by the persistence of microorganisms in bronchoscopes despite repeated disinfections. However, the risk of persistent contamination was not associated with the age of the bronchoscope. CONCLUSIONS: Our results confirm that bronchoscopes can remain contaminated despite repeated reprocessing. Routine microbial testing of bronchoscopes for quality assurance and audit of decontamination and disinfection procedures can improve the reprocessing of bronchoscopes and minimize the rate of persistent contamination.

Comparative Genomic Analysis and Phenotypic Characterization of Bronchoscope-Associated Klebsiella aerogenes.

Bronchoscopes have been linked to outbreaks of nosocomial infections. The phenotypic and genomic profiles of bronchoscope-associated Klebsiella aerogenes isolates are largely unknown. In this work, a total of 358 isolates and 13 isolates were recovered from samples after clinical procedures and samples after decontamination procedures, respectively, over the five months. Antimicrobial susceptibility testing found seven K. aerogenes isolates exhibiting a low-level resistance to antimicrobial agents. Among seven K. aerogenes isolates, we found five sequence types (STs) clustered into three main clades. Collectively, this study described for the first time the phenotypic and genomic characteristics of bronchoscope-associated K. aerogenes.

Bronchoscopy during the COVID-19 pandemic: effect on current practices and strategies to reduce procedure-associated transmission.

Introduction: Bronchoscopy and related procedures have unambiguously been affected during the Corona Virus Disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome-Corona Virus-2 (SARS COV-2). Ordinary bronchoscopy practices and lung cancer services might have changed over this pandemic and for the years to come.Areas covered: This manuscript summarizes the utility of bronchoscopy in COVID-19 patients, and the impact of the pandemic in lung cancer diagnostic services, in view of possible viral spread during these We conducted a literature review of articles published in PubMed/Medline from inception to November 5th, 2020 using relevant terms.Expert opinion: Without doubt this pandemic has changed the way bronchoscopy and related procedures are being performed. Mandatory universal personal protective equipment, pre-bronchoscopy PCR tests, dedicated protective barriers and disposable bronchoscopes might be the safest and simpler way to perform even the most complicated procedures.

A Manufacturer and User Facility Device Experience Analysis of Upper Aerodigestive Endoscopy Contamination: Is Flexible Laryngoscopy Different?

OBJECTIVES/HYPOTHESIS: Several recent studies have observed a high incidence of duodenoscope microbial contamination and an association of contamination with healthcare-acquired infections. This study sought to quantify nasopharyngoscope microbial contamination relative to that of other endoscope categories and characterize the manufacturers, outcomes, and microbial profiles associated with these cases. STUDY DESIGN: Retrospective, cross-sectional study. METHODS: A total of 3,865 adverse events were collected from 2013 to 2019 using the US Food and Drug Administration Manufacturer and User Facility Device Experience database. The fraction of total device failures associated with contamination was quantified for nasopharyngoscopes, bronchoscopes, duodenoscopes, and gastroscopes. Odds ratios of nasopharyngoscope contamination compared to that of bronchoscopes, duodenoscopes, or gastroscopes were calculated, and significance was assessed by χ2 analysis. The Kruskal-Wallis test was used for nonparametric testing of significance. RESULTS: Nasopharyngoscope device failures were reported at an incidence of 0.646 per month; 34.1% involved contamination, comparable to the frequency observed for bronchoscopes (23.4%, P = .118), duodenoscopes (29.2%, P = .493), and gastroscopes (45.3%, P = .178). The frequency of device contamination was observed to be significantly higher for a particular endoscope manufacturer regardless of endoscope category (Kruskal-Wallis P = .021). In instances of contamination, nasopharyngoscopes were significantly less associated with patient harm or death than bronchoscope (odds ratio [OR] = 10.2) and duodenoscope (OR = 4.81) cases. CONCLUSIONS: Although the rates of contamination were comparable across all endoscope categories, nasopharyngoscope contamination was less commonly associated with patient harm or death. In an era of rising healthcare costs, determining adequate disinfection standards for nasopharyngoscopes and their impact on patient safety is crucial. LEVEL OF EVIDENCE: NA Laryngoscope, 131:598-605, 2021.

A pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, United Kingdom.

Outbreaks of fungal infections due to emerging and rare species are increasingly reported in healthcare settings. We investigated a pseudo-outbreak of Rhinocladiella similis in a bronchoscopy unit of a tertiary care teaching hospital in London, UK. We aimed to determine route of healthcare-associated transmission and prevent additional infections. From July 2018 through February 2019, we detected a pseudo-outbreak of R. similis isolated from bronchoalveolar lavage (BAL) fluid samples collected from nine patients who had undergone bronchoscopy in a multispecialty teaching hospital, during a period of 8 months. Isolates were identified by MALDI-TOF mass spectrometry. Antifungal susceptibility testing was performed by EUCAST broth microdilution. To determine genetic relatedness among R. similis isolates, we undertook amplified fragment length polymorphism analysis. To determine the potential source of contamination, an epidemiological investigation was carried out. We reviewed patient records retrospectively and audited steps taken during bronchoscopy as well as the subsequent cleaning and decontamination procedures. Fungal cultures were performed on samples collected from bronchoscopes and automated endoscope washer-disinfector systems. No patient was found to have an infection due to R. similis either before or after bronchoscopy. One bronchoscope was identified to be used among all affected patients with positive fungal cultures. Physical damage was found in the index bronchoscope; however, no fungus was recovered after sampling of the affected scope or the rinse water of automated endoscope washer-disinfectors. Use of the scope was halted, and, during the following 12-month period, Rhinocladiella species were not isolated from any BAL specimen. All pseudo-outbreak isolates were identified as R. similis with high genetic relatedness (>90% similarity) on ALFP analysis. The study emphasises the emergence of a rare and uncommon black yeast R. similis, with reduced susceptibility to echinocandins, in a bronchoscope-related pseudo-outbreak with a potential water-related reservoir. Our findings highlight the importance of prolonged fungal culture and species-level identification of melanised yeasts isolated from bronchoscopy samples. Possibility of healthcare-associated transmission should be considered when R. similis is involved in clinical microbiology samples.

Bronchoscope-Related "Superbug" Infections.

Several recent cases associating cleaned and high-level disinfected duodenoscopes with outbreaks of carbapenem-resistant Enterobacteriaceae (CRE) and related multidrug-resistant organisms (MDROs) may cause bronchoscopists, pulmonologists, and other stakeholders to inquire about the effectiveness of today's practices for reprocessing flexible bronchoscopes. The primary objectives of this study were to address this question and investigate the risk of bronchoscopes transmitting infections of CRE and related MDROs. The published literature and the US Food and Drug Administration's medical device database of adverse events were searched beginning in 2012, when endoscopy first emerged as a recognized risk factor for transmission of CRE. The Internet was also searched during this same time frame to identify other relevant cases. Several cases associating reprocessed bronchoscopes with infections of CRE or a related MDRO were identified. This study's findings suggest that bronchoscopes may pose an underrecognized potential for transmission of CRE and related MDROs, warranting greater public awareness, enhanced preventive measures, and updated reprocessing guidance. This study's data also suggest that the cleaning and high-level disinfection of bronchoscopes performed in accordance with published guidelines and manufacturer instructions may not always be sufficiently effective to eliminate this risk. Several factors were identified that can adversely affect a bronchoscope's reprocessing and pose a risk of transmission of these multidrug-resistant bacteria, including use of a damaged or inadequately serviced bronchoscope, and formation of an inaccessible biofilm. Recommendations are provided to improve the safety of flexible bronchoscopes, including supplementing their reprocessing with an enhanced measure such as sterilization when warranted, and strict adherence to a periodic servicing and maintenance schedule consistent with the bronchoscope manufacturer's instructions.

Bronchoscope-related Pseudomonas aeruginosa pseudo-outbreak attributed to contaminated rinse water.

BACKGROUND: Increased percentage of Pseudomonas aeruginosa from bronchoalveolar lavage fluid of patients in June 2016 was observed. P aeruginosa were also obtained from flexible bronchoscope and rinse water in the microbiological surveillance in June 2016. METHODS: Reprocessing procedure of bronchoscope was assessed, and environmental samples were collected. P aeruginosa isolates recovered from bronchoalveolar lavage fluid of patients between May and September 2016 and environment were characterized using multilocus sequence typing and pulsed-field gel electrophoresis. RESULTS: A novel multilocus sequence type (ST) of P aeruginosa was defined as ST 2387. ST671 and ST 2387 were both cultured from bronchoscopes and connecting tube in manual reprocessing cleaning equipment. One strain from a patient was indistinguishable from the clones obtained from the bronchoscope and connecting tube revealed by pulsed-field gel electrophoresis. Two strains from 2 patients from the burn intensive care unit were identical, and highly related to 2 other strains from the burn intensive care unit. The persistence of P aeruginosa in bronchoscopes, connecting tubes, and final rinse water was terminated by replacement of the connecting tube. CONCLUSIONS: We report a pseudo-outbreak of P aeruginosa associated with bronchoscope, for which connecting tube was the hidden reservoir for contaminating bronchoscopes. This highlights that effective measures are needed to control the bacterial load in final rinsing water to protect reusable equipment from contamination in reprocessing and cleaning.

An investigation of Stenotrophomonas maltophilia-positive culture caused by fiberoptic bronchoscope contamination.

BACKGROUND: Stenotrophomonas maltophilia (SMA) is present in hospital environments and has been one of the pathogens that cause nosocomial contamination and infections. To investigate the occurrence of Stenotrophomonas maltophilia (SMA) in bronchoscope lavage fluid (BALF) among 25 cases treated in the Division of Infection and to trace the contamination source and transmission route. METHODS: 25 cases of SMA positive BALF occurring from May 11 to August 10, 2018 were tested for drug sensitivity. Environmental hygiene conditions were investigated to identify the source of contamination and the route of transmission. RESULTS: BALF associated SMA was in all cases sensitive to minocycline, levofloxacin and chloramphenicol and resistant to ceftazidime and imipenem. 92.3% of samples were sensitivity to compound sulfamethoxazole. Investigation of environmental hygiene parameters revealed SMA growing on the inner wall of the fiberoptic bronchoscope as a likely source of contamination. CONCLUSION: Incomplete cleaning and sterilization of the fiberoptic bronchoscope led to SMA nosocomial contamination. Strict sterilization procedures are required to prevent and control nosocomial contamination.

Bronchoscope-associated clusters of multidrug-resistant Pseudomonas aeruginosa and carbapenem-resistant Klebsiella pneumoniae.

OBJECTIVE: Recovery of multidrug-resistant (MDR) Pseudomonas aeruginosa and Klebsiella pneumoniae from a cluster of patients in the medical intensive care unit (MICU) prompted an epidemiologic investigation for a common exposure. METHODS: Clinical and microbiologic data from MICU patients were retrospectively reviewed, MICU bronchoscopes underwent culturing and borescopy, and bronchoscope reprocessing procedures were reviewed. Bronchoscope and clinical MDR isolates epidemiologically linked to the cluster underwent molecular typing using pulsed-field gel electrophoresis (PFGE) followed by whole-genome sequencing. RESULTS: Of the 33 case patients, 23 (70%) were exposed to a common bronchoscope (B1). Both MDR P. aeruginosa and K. pneumonia were recovered from the bronchoscope's lumen, and borescopy revealed a luminal defect. Molecular testing demonstrated genetic relatedness among case patient and B1 isolates, providing strong evidence for horizontal bacterial transmission. MDR organism (MDRO) recovery in 19 patients was ultimately linked to B1 exposure, and 10 of 19 patients were classified as belonging to an MDRO pseudo-outbreak. CONCLUSIONS: Surveillance of bronchoscope-derived clinical culture data was important for early detection of this outbreak, and whole-genome sequencing was important for the confirmation of findings. Visualization of bronchoscope lumens to confirm integrity should be a critical component of device reprocessing.

Mycobacterium avium pseudo-outbreak associated with an outpatient bronchoscopy clinic: Lessons for reprocessing.

We identified a pseudo-outbreak of Mycobacterium avium in an outpatient bronchoscopy clinic following an increase in clinic procedure volume. We terminated the pseudo-outbreak by increasing the frequency of automated endoscope reprocessors (AER) filter changes from quarterly to monthly. Filter changing schedules should depend on use rather than fixed time intervals.

Microbiological surveillance of flexible bronchoscopes after a high-level disinfection with peracetic acid: preliminary results from an Italian teaching hospital.

BACKGROUND: Flexible bronchoscopes are heat labile, complex and difficult to clean, and some nosocomial outbreaks related to bronchoscopy have been reported in literature. The aim of our study was to determine, through a systematic monitoring, whether bronchoscopes' cleaning and disinfection procedures have been correctly adopted by health operators. METHODS: We conducted a 19 months-long prospective study in the Unit of Pulmonology at Careggi Teaching Hospital (Florence, Italy), analyzing endoscopes that were reprocessed through a high-level disinfection procedure. Samples collection was performed weekly by two trained operators. Results were organized in a database and then exported for descriptive and inferential statistical analysis. RESULTS: From February 2016 to September 2017 we collected 218 samples from bronchoscopes' valves (N=109) and from their inner channels (N=109). Staphylococci were found in 34 samples (15.69% of all samples). Pseudomonas was found in 11 samples (5.04% of all samples). Pseudomonas aeruginosa wasn't found in any sample. CONCLUSIONS: Our results came out to be better than similar studies in literature and demonstrated that a correct endoscopes' hygiene should be part of a more complex strategy of surveillance and control of healthcare-associated infections. However, a continuous monitoring of endoscopes could provide a wider view about this problem, and more reliable results.

Hospital bronchoscopy-related pseudo-outbreak caused by a circulating Mycobacterium abscessus subsp. massiliense.

Adolfo Lutz Institute in Sao Paolo State performs mycobacterial identification for many healthcare units, and in 2008 identified a possible outbreak involving patients submitted to bronchoscopy at the same hospital. This study aimed to analyse the clonality of isolates. Mycobacterium abscessus subsp. massiliense isolated from 28 patients, water from one bronchoscope and water from four automated endoscope reprocessing machines presented high similarity by pulsed-field gel electrophoresis. This strain was not found in the water supply, and it was hypothesized that an infected patient contaminated the bronchoscope, with further false-positive cultures from subsequent patients.

Effectiveness of Reprocessing for Flexible Bronchoscopes and Endobronchial Ultrasound Bronchoscopes.

BACKGROUND: 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. This multisite, prospective study evaluated the effectiveness of real-world bronchoscope reprocessing methods, using a systematic approach. METHODS: This 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 (ATP). Researchers assessed reprocessing practices, and storage cabinet cleanliness was evaluated by visual inspection and ATP tests. RESULTS: Researchers examined 24 clinically used bronchoscopes. After manual cleaning, 100% of bronchoscopes had residual contamination. Microbial growth was found in 14 fully reprocessed bronchoscopes (58%), including mold, Stenotrophomonas maltophilia, and Escherichia coli/Shigella species. Visible irregularities were observed in 100% 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. CONCLUSIONS: 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.

Contamination of single-use bronchoscopes in critically ill patients.

Disposable bronchoscopes such as the Ambu aScopeTM 3 are marketed as 'single use' The risks of contamination from prolonged device storage before possible re-use are unknown. Following clinical bronchoscopy in patients whose lungs were mechanically ventilated, 20 aScopeTM 3's bronchoscopes received a standard 'social clean' and were then stored. Subsequent paired saline flush and swab samples were taken at time zero, and at 24 h and 48 h. Positive microbiological cultures were obtained from at least one time point from 16 of the 20 bronchoscopes. Pathogens considered at high risk of causing pneumonia were isolated from seven bronchoscopes, with significant quantities from six of them. Our study demonstrates that aScopeTM 3's should not be re-used on the same patient, as clinically significant growth of micro-organisms occurs frequently, despite adequate social cleaning. Culture of bronchoscopes themselves may be a potentially useful diagnostic tool in the context of pulmonary infection. Our data make it clear that these devices are single use and not single patient use.

Disposable Bronchoscope Model for Simulating Endoscopic Reprocessing and Surveillance Cultures.

BACKGROUND Endoscope-associated infections are reported despite following proper reprocessing methods. Microbiological testing can confirm the adequacy of endoscope reprocessing. Multiple controversies related to the method and interpretation of microbiological testing cultures have arisen that make their routine performance a complex target. OBJECTIVE We conducted a pilot study using disposable bronchoscopes (DBs) to simulate different reprocessing times and soaking times and to compare high-level disinfection versus ethylene oxide sterilization. We also reviewed the time to reprocessing and duration of the procedures. METHODS Bronchoscopes were chosen because an alternative disposable scope is commercially available and because bronchoscopes are more prone to delays in processing. Disposable bronchoscopes were contaminated using a liquid bacterial suspension and were then incubated for 1-4 hours. Standard processing and high-level disinfection were performed on 36 endoscopes. Ethylene oxide sterilization was performed on 21 endoscopes. Endoscope cultures were performed using the standard "brush, flush, brush" technique. RESULTS After brushing was performed, a final water-flush culture procedure was the most effective method of detecting bacterial persistence on the disposable scopes. Klebsiella pneumoniae was the most commonly recovered organism after reprocessing. Ethylene oxide sterilization did not result in total elimination of viable bacteria. CONCLUSION Routine endoscopy cultures may be required to assess the adequacy of endoscopic processing. Infect Control Hosp Epidemiol 2017;38:136-142.

Mycobacterial contamination of bronchoscopes: Challenges and possible solutions in low resource settings.

The use of bronchoscopes has increased in tuberculosis (TB) diagnostics to circumvent the diagnostic challenges that are associated with low sputum volume and smear-negative TB. In healthcare facilities situated in low income countries that have a high burden of TB, adequate decontamination of bronchoscopes is a challenge and often overlooked to save on time and costs. This amplifies the risk of outbreaks and pseudo-outbreaks due to Mycobacterium tuberculosis and nontuberculosis mycobacteria. In this minireview, we review published literature of contaminated bronchoscopes causing pseudo-outbreaks of M. tuberculosis and nontuberculosis mycobacteria in an effort to determine common sources, and possible mitigation strategies in low-resource settings.