Pseudo-outbreak of Mycobacterium fortuitum in a hospital bronchoscopy unit

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.

Environmental Sources and Transmission of Nontuberculous Mycobacteria

The field of environmental nontuberculous mycobacteria (NTM) is benefiting from a new era of genomics that has catapulted our understanding of preferred niches, transmission, and outbreak investigations. The ability to forecast environmental features that promote or reduce environmental NTM prevalence will greatly improve with coordinated environmental sampling and by elevating the necessity for uniform disease notifications. Studies that synergize environmental biology, isolate notifications, and comparative genomics in prospective, longitudinal studies, particularly during climate changes and weather events, will be useful to solve longstanding NTM public health quandaries.

Pseudo-outbreak of Mycobacterium lentiflavum at a general hospital in Japan

BACKGROUND

Mycobacterium lentiflavum is a slow-growing nontuberculous mycobacterium that is widely distributed in soil and water systems, but it is sometimes pathogenic to humans. Although cases of M. lentiflavum infections are rare, 22 isolates of M. lentiflavum were identified at a single hospital in Japan. We suspected a nosocomial outbreak; thus, we conducted transmission pattern and genotype analyses.

METHODS

Cases of M. lentiflavum isolated at Kushiro City General Hospital in Japan between May 2020 and April 2021 were analyzed. The patient samples and environmental culture specimens underwent whole-genome sequencing (WGS). Additionally, we retrospectively collected clinical data from patient medical records.

RESULTS

Altogether, 22 isolates of M. lentiflavum were identified from sputum and bronchoalveolar lavage samples. Clinically, the instances with M. lentiflavum isolates were considered contaminants. In the WGS analysis, 19 specimens, including 18 patient samples and 1 environmental culture from the hospital's faucet, showed genetic similarity. The frequency of M. lentiflavum isolation decreased after we prohibited the use of taps where M. lentiflavum was isolated.

CONCLUSIONS

WGS analysis identified that the cause of M. lentiflavum pseudo-outbreak was the water used for patient examinations, including bronchoscopy.

A narrative review of nontuberculous mycobacterial pulmonary disease: microbiology, epidemiology, diagnosis, and management challenges

INTRODUCTION

Nontuberculous mycobacteria (NTM) are a diverse group of mycobacterial species that are ubiquitous in the environment. They are opportunistic pathogens that can cause a range of diseases, especially in individuals with underlying structural lung disease or compromised immune systems.

AREAS COVERED

This paper provides an in-depth analysis of NTM infections, including microbiology, environmental sources and transmission pathways, risk factors for disease, epidemiology, clinical manifestations and diagnostic approaches, guideline-based treatment recommendations, drugs under development, and management challenges.

EXPERT OPINION

Future approaches to the management of NTM pulmonary disease will require therapies that are well tolerated, can be taken for a shorter time period and perhaps less frequently, have few drug-drug interactions, and are active against the various strains of pathogens. As the numbers of infections increase, such therapies will be welcomed by clinicians and patients.

Systematic Review and Cost-Consequence Analysis of Ambu aScope 5 Broncho Compared with Reusable Flexible Bronchoscopes: Insights from Two US University Hospitals and an Academic Institution

OBJECTIVE

The aim of this study was to perform a systematic review, meta-analysis and cost-consequence analysis of the single-use bronchoscope, Ambu aScope^TM 5 Broncho, in relation to reusable flexible bronchoscopes (RFB) available within three high procedure volume university hospitals and academic institutions in the USA.

METHODS

The primary outcome was incremental cost and the secondary outcome was incremental cross-infection risk of use for both the single-use flexible bronchoscope (SUFB) and RFBs. Cost estimates included capital, repair, and reprocessing costs derived from a prospective observational micro-costing approach within three large university hospitals and academic institutions. All costs were valued in 2022 US dollars (USD). A meta-analysis based on literature covering cross-contamination and infection from 2010 to 2020 investigated cross-infection risk following bronchoscopy procedures with RFBs. Capital costs were discounted at 3% over 5-8 years. All parameters were evaluated using both univariate deterministic and probabilistic sensitivity analyses.

RESULTS

In high-volume hospitals, RFBs were cost minimizing compared to SUFBs. Probabilistic sensitivity analysis showed that RFBs were cost saving in 88% of iterations. Univariate analyses illustrated sensitivity of the base-case result to the procedure volume. Data from sensitivity analyses suggest that the two interventions are cost neutral at a break-even point of 756 procedures per year or 46 procedures per bronchoscope per year.

CONCLUSION

Assuming equivalent clinical performance, single-use flexible bronchoscopes are not cost minimizing when including the costs associated with cross-infection in high-volume US university hospitals and academic institutions. Overall, the benefits of conversion from RFBs to SUFBs are dependent on the annual procedure volume of individual hospitals, expected cross-infection risk, and purchase price of the aScope 5 Broncho.

Mitigation of nontuberculous mycobacteria in hospital water: challenges for infection prevention

PURPOSE OF REVIEW

The purpose of this review is to summarize recent literature on nontuberculous mycobacteria in water of healthcare systems. Despite improvement in identification techniques and emergence of infection prevention and control programs, nontuberculous mycobacteria remain present in hospital water systems, causing outbreaks and pseudo-outbreaks in healthcare settings.

RECENT FINDINGS

Waterborne outbreaks and pseudo-outbreaks of nontuberculous mycobacteria continue to affect hospitals. Improvements in methods of identification and investigation, including MALDI-TOF and whole genome sequencing with evaluation of single nucleotide polymorphisms, have been used successfully in outbreak and pseudo-outbreak investigations. Recent studies have shown control of outbreaks in immunocompromised patients through the use of sterile water for consumption, as well as control of pseudo-outbreaks by using sterile water for procedures. Construction activities have been implicated in outbreaks and pseudo-outbreaks of nontuberculous mycobacteria. Water management programs are now required by the Joint Commission, which will likely improve water risk mitigation.

SUMMARY

Improvement in detection and identification of nontuberculous mycobacteria has led to increasing recognition of waterborne outbreaks and pseudo-outbreaks. Water management programs are of vital importance in infection prevention.

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.

Non-Tuberculous Mycobacteria: Molecular and Physiological Bases of Virulence and Adaptation to Ecological Niches

Non-tuberculous mycobacteria (NTM) are paradigmatic colonizers of the total environment, circulating at the interfaces of the atmosphere, lithosphere, hydrosphere, biosphere, and anthroposphere. Their striking adaptive ecology on the interconnection of multiple spheres results from the combination of several biological features related to their exclusive hydrophobic and lipid-rich impermeable cell wall, transcriptional regulation signatures, biofilm phenotype, and symbiosis with protozoa. This unique blend of traits is reviewed in this work, with highlights to the prodigious plasticity and persistence hallmarks of NTM in a wide diversity of environments, from extreme natural milieus to microniches in the human body. Knowledge on the taxonomy, evolution, and functional diversity of NTM is updated, as well as the molecular and physiological bases for environmental adaptation, tolerance to xenobiotics, and infection biology in the human and non-human host. The complex interplay between individual, species-specific and ecological niche traits contributing to NTM resilience across ecosystems are also explored. This work hinges current understandings of NTM, approaching their biology and heterogeneity from several angles and reinforcing the complexity of these microorganisms often associated with a multiplicity of diseases, including pulmonary, soft-tissue, or milliary. In addition to emphasizing the cornerstones of knowledge involving these bacteria, we identify research gaps that need to be addressed, stressing out the need for decision-makers to recognize NTM infection as a public health issue that has to be tackled, especially when considering an increasingly susceptible elderly and immunocompromised population in developed countries, as well as in low- or middle-income countries, where NTM infections are still highly misdiagnosed and neglected.