Outbreaks of contaminated broncho-alveolar lavage related to intrinsically defective bronchoscopes

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.

Usefulness of linked data for infectious disease events: a systematic review

Surveillance is a key public health function to enable early detection of infectious disease events and inform public health action. Data linkage may improve the depth of data for response to infectious disease events. This study aimed to describe the uses of linked data for infectious disease events. A systematic review was conducted using Pubmed, CINAHL and Web of Science. Studies were included if they used data linkage for an acute infectious disease event (e.g. outbreak of disease). We summarised the event, study aims and designs; data sets; linkage methods; outcomes reported; and benefits and limitations. Fifty-four studies were included. Uses of linkage for infectious disease events included assessment of severity of disease and risk factors; improved case finding and contact tracing; and vaccine uptake, safety and effectiveness. The ability to conduct larger scale population level studies was identified as a benefit, in particular for rarer exposures, risk factors or outcomes. Limitations included timeliness, data quality and inability to collect additional variables. This review demonstrated multiple uses of data linkage for infectious disease events. As infectious disease events occur without warning, there is a need to establish pre-approved protocols and the infrastructure for data-linkage to enhance information available during an event.

Comparison of channel sampling methods and brush heads in surveillance culture of endoscope reprocessing: A propensity score matching and paired study

BACKGROUND

Endoscopy-related infections have caused multiple outbreaks. The importance of surveillance culture is gradually recognized, but sampling techniques are not consistent in many guidelines. It is unclear whether the Flush-Brush-Flush sampling method (FBFSM) is more sensitive than the conventional flush sampling method (CFSM) and whether different sampling brushes have different effects.

METHODS

The propensity score matching method was done with two matching ways, 1:1 nearest neighbor propensity score matching and full matching was used to analyze the surveillance culture data collected by FBFSM and CFSM. We fit a confounder-adjusted multiple generalized linear logistic regression model to estimate the marginal odds ratio (OR). A paired study was applied to compare the sampling effect of polyurethane foam (PU) head brush and polyamide (PA) head brush.

RESULT

From 2016 to 2020, 316 reprocessed endoscope samples were collected from all 59 endoscopy centers in Tianjin. About 279 (88.3%) reprocessed endoscopes met the threshold of Chinese national standards (<20 CFU/Channel). The qualified rate of reprocessed endoscopes sampling by CFSM (91.8%) and FBFSM (81.6%) was statistically different (p < 0.05). The adjusted OR by full matching for FBFSM was 7.98 (95% confidence interval: 3.35-21.78). Forty one pairs of colonoscopes, after reprocessing from 27 centers, were tested by PA and PU brushes, and no difference was found in microbial recovery.

CONCLUSION

FBFSM was confirmed to be a more sensitive sampling technique. PU and PA brushes had no significant difference in sampling effect.

A systematic review and cost effectiveness analysis of reusable vs. single-use flexible bronchoscopes

The cost effectiveness of reusable vs. single‐use flexible bronchoscopy in the peri‐operative setting has yet to be determined. We therefore aimed to determine this and hypothesised that single‐use flexible bronchoscopes are cost effective compared with reusable flexible bronchoscopes. We conducted a systematic review of the literature, seeking all reports of cross‐contamination or infection following reusable bronchoscope use in any clinical setting. We calculated the incidence of these outcomes and then determined the cost per patient of treating clinical consequences of bronchoscope‐induced infection. We also performed a micro‐costing analysis to quantify the economics of reusable flexible bronchoscopes in the peri‐operative setting from a high‐throughput tertiary centre. This produced an accurate estimate of the cost per use of reusable flexible bronchoscopes. We then performed a cost effectiveness analysis, combining the data obtained from the systematic review and micro‐costing analysis. We included 16 studies, with a reported incidence of cross‐contamination or infection of 2.8%. In the micro‐costing analysis, the total cost per use of a reusable flexible bronchoscope was calculated to be £249 sterling. The cost per use of a single‐use flexible bronchoscope was £220 sterling. The cost effectiveness analysis demonstrated that reusable flexible bronchoscopes have a cost per patient use of £511 sterling due to the costs of treatment of infection. The findings from this study suggest benefits from the use of single‐use flexible bronchoscopes in terms of cost effectiveness, cross‐contamination and resource utilisation.

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.

Comparison of Two Culture Methods for Use in Assessing Microbial Contamination of Duodenoscopes

Recent outbreaks of carbapenem-resistant Enterobacteriaceae infections associated with duodenoscopes used for endoscopic retrograde cholangiopancreatography have highlighted the challenge of cleaning and high-level disinfection of these instruments. The Food and Drug Administration has suggested that duodenoscope surveillance by microbiological culturing, along with strict adherence to reprocessing protocols, may help reduce the risk of duodenoscope-associated infection transmission. We developed and validated an effective, user-friendly duodenoscope sampling and culture protocol and compared its performance to the interim Centers for Disease Control and Prevention-recommended guidelines. Our protocol resulted in a 65% recovery rate for Gram-negative organisms, demonstrating a 2-fold increased recovery rate compared to the CDC method. The implementation of this protocol may increase the feasibility of duodenoscope surveillance for microbiology laboratories and endoscopy departments.

Infectious diseases linked to cross-contamination of flexible endoscopes

Flexible endoscopes are widely used to examine, diagnose, and treat medical disorders. While the risk of endoscopy-related transmission of infection is estimated to be very low, more health care-associated infections are related to contaminated endoscopes than to any other medical device. Flexible endoscopes can get highly contaminated with microorganisms, secretions and blood during use. The narrow lumens and multiple internal channels make the cleaning of flexible endoscopes a complex and difficult task. Despite the availability of international, national and local endoscope reprocessing guidelines, contamination and transmission of microorganisms continue to occur. These transmissions are mostly related to the use of defective equipment, endoscope reprocessing failures, and noncompliance with recommended guidelines. This article presents an overview of publications about case reports and outbreaks related to contamination of flexible endoscopes.

Caveat Emptor: The Role of Suboptimal Bronchoscope Repair Practices by a Third-Party Vendor in a Pseudo-Outbreak ofPseudomonasin Bronchoalveolar Lavage Specimens

Objective.

To describe a pseudo-outbreak associated with loose bronchoscope biopsy ports caused by inadequate bronchoscope repair practices by third-party vendors and to alert healthcare personnel to assess bronchoscope repair practices.

Design.

Outbreak investigation.

Setting.

A 925-bed tertiary care hospital in Baltimore, Maryland.

Patients.

Patients who underwent bronchoscopy with certain bronchoscopes after they had been repaired by a third-party vendor.

Methods.

An epidemiologic investigation was conducted to determine the cause ofPseudomonas putidagrowth in 4 bronchoalveolar lavage (BAL) specimens within a 3-day period in May 2008. All bronchoscopes were inspected, and cultures were obtained from bronchoscopes and the environment. Bronchoscope cleaning and maintenance practices were reviewed. Microbiologic results from BAL specimens and medical records were reviewed to find additional cases.

Results.

All 4 case patients had undergone bronchoscopy with one of 2 bronchoscopes, both of which had loose biopsy ports. Bronchoscope cultures grewP. putida, Pseudomonas aeruginosa,andStenotrophomonas.TheP. putidastrains from the bronchoscopes matched those from the patients. Specimens from 12 additional patients who underwent bronchoscopy with these bronchoscopes grewP. putida, P. aeruginosa,orStenotrophomonas.No patients developed clinical signs or symptoms of infection, but 7 were treated with antibiotics. Investigation revealed that the implicated bronchoscopes had been sent to an external vendor for repair; examination by the manufacturer revealed irregularities in repairs and nonstandard part replacements.

Conclusions.

Third-party vendors without access to proprietary information may contribute to mechanical malfunction of medical devices, which can lead to contamination and incomplete disinfection.

Infect Control Hosp Epidemiol2012;33(3):224-229

Klebsiella spp. in endoscopy-associated infections: we may only be seeing the tip of the iceberg

PURPOSE

Two endoscopy-associated nosocomial outbreaks caused by carbapenemase-producing Klebsiella pneumoniae (CPKP) were recently observed in two German hospitals. In this study, we performed a systematic search of the medical literature in order to elucidate the epidemiology of Klebsiella spp. in endoscopy-associated outbreaks.

METHODS

Medline, the Outbreak Database ( http://www.outbreak-database.com ) and reference lists of articles extracted from these databases were screened for descriptions of endoscopy-associated nosocomial outbreaks. The data extracted and analysed were: (1) the type of medical department affected; (2) characterisation of pathogen to species and conspicuous resistance patterns (if applicable); (3) type of endoscope and the grade of its contamination; (4) number and the types of infections; (5) actual cause of the outbreak.

RESULTS

A total of seven nosocomial outbreaks were identified, of which six were outbreaks of endoscopic retrograde cholangiopancreatography-related infections and caused by contaminated duodenoscopes. Including our own outbreaks in the analysis, we identified one extended-spectrum beta-lactamase-producing K. pneumoniae strain and six CPKP strains. Insufficient reprocessing after the use of the endoscope was the main reason for subsequent pathogen transmission.

CONCLUSIONS

There were only two reports of nosocomial outbreaks due to Klebsiella spp. in the first three decades of endoscopic procedures, but seven additional outbreaks of this kind have been reported within the last 4 years. It is very likely that many of such outbreaks have been missed in the past because this pathogen belongs to the physiological gut flora. However, with the emergence of highly resistant (carbapenemase-producing) strains, strict adherence to infection control guidelines is more important than ever.

Transmission of infection by flexible gastrointestinal endoscopy and bronchoscopy

Flexible endoscopy is a widely used diagnostic and therapeutic procedure. Contaminated endoscopes are the medical devices frequently associated with outbreaks of health care-associated infections. Accurate reprocessing of flexible endoscopes involves cleaning and high-level disinfection followed by rinsing and drying before storage. Most contemporary flexible endoscopes cannot be heat sterilized and are designed with multiple channels, which are difficult to clean and disinfect. The ability of bacteria to form biofilms on the inner channel surfaces can contribute to failure of the decontamination process. Implementation of microbiological surveillance of endoscope reprocessing is appropriate to detect early colonization and biofilm formation in the endoscope and to prevent contamination and infection in patients after endoscopic procedures. This review presents an overview of the infections and cross-contaminations related to flexible gastrointestinal endoscopy and bronchoscopy and illustrates the impact of biofilm on endoscope reprocessing and postendoscopic infection.

Evidence-based spectrum of antimicrobial activity for disinfection of bronchoscopes

Summary

Processing of bronchoscopes after a physical examination has to eliminate all micro-organisms that could have contaminated the endoscope and that may harm the following patient. The aim of this analysis is to define those micro-organisms that may contaminate the bronchoscope during the examination and that may cause disease in other patients.

Methods

Research of literature and analysis of laboratory data.

Results

During the passage of the respiratory tract the bronchoscope will be contaminated by the physiological flora of oral cavity, nasopharynx, trachea, bronchi, and pulmonary tissues. Whilst the oral cavity, the nasopharynx and the pharynx are the habitat for a great variety of bacteria the lower respiratory tract is virtually free of micro-organisms. However, in ventilated patients trachea and bronchi can become colonized as the result of bypassing the cleansing effect of the ciliated epithelium. In addition all agents that can cause bronchitis or pneumonia in immunocompromised or otherwise healthy individuals are potential contaminants of bronchoscopes. These microorganisms include bacteria, mycobacteria, yeasts and moulds, enveloped and non-enveloped viruses and rarely parasites.

The bronchoscopic procedure can result in epithelial injury with subsequent bleeding. Therefore, all blood-borne pathogens, e.g. HIV or HBV are also potential contaminants of the bronchoscope.

There are several reports of transmission of micro-organisms due to incomplete or faulty cleaning and disinfection procedures of bronchoscopes. These incidents include nearly all classes of micro-organisms but not parasites or viruses. However, the incubation period of viruses can be long and the association between bronchoscopy and infection may be obscure.

Endospore forming micro-organisms and parasites are not part of the normal flora of the respiratory tract and may rarely cause disease, usually only in severely immunocompromised patients, but transmission of such organisms by bronchoscopy has never been reported.

Conclusion

The antimicrobial activity of the disinfection process, including chemical disinfectants for endoscopes has to include bacteria, fungi and viruses. Sporicidal activity may be only warranted in specific patient populations, i.e. after bronchoscopy of suspected anthrax patients or before examination of severely immunocompromised patients.