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Bronchoscopy-Related Infections and Pseudoinfections -- New York, 1996 and 1998

Bronchoscopy is a useful diagnostic technique that can be performed safely by trained specialists when the bronchoscopes in both inpatient and ambulatory-care settings are reprocessed properly to prevent transmission of infection. The New York State Department of Health received reports of three clusters of culture-positive bronchoscopy specimens obtained in 1996 and 1998 from patients at local health-care facilities. This report summarizes the results of investigations of these clusters, which indicated involvement of Mycobacterium tuberculosis, M. intracellulare, or imipenem-resistant Pseudomonas aeruginosa. Between patient uses, bronchoscopes had been cleaned, visually inspected, leak tested, and processed by STERIS System 1 processors (STERIS, Mentor, Ohio)*.

Cluster 1

During November-December 1996, bronchial specimens from five patients at a health-care facility yielded M. tuberculosis with the same restriction fragment length polymorphism (RFLP) pattern suggesting a common source. The index case-patient had tuberculosis with persistent acid-fast bacillus (AFB) smear- and culture-positive specimens. The four subsequent case-patients had no clinical evidence of tuberculosis, although one had a positive tuberculin skin test 6 weeks postbronchoscopy and was treated with isoniazid. Investigators concluded that all specimens from the four patients were contaminated but could not determine whether contamination occurred during the bronchoscopy or in the mycobacteriology laboratory. Specimens from three of the four case-patients were processed in the laboratory on the same day as the index case-patient's specimen.

The bronchoscopies were performed using three Olympus BF-P20D (Olympus America, Inc., Melville, New York) bronchoscopes, each processed in the same STERIS System 1 processor. Cultures from all three bronchoscopes, taken 5 weeks after the last case procedure, were negative. The same cleaning brushes used on all three bronchoscopes also were culture negative. Investigators identified an inconsistency between the disinfection/sterilization procedures recommended in the STERIS manual and those followed by the facility personnel--the biopsy port cap was not replaced before loading for cleaning in the STERIS System 1 processor. The bronchoscope manufacturer did not provide recommendations for processing in the STERIS System 1, but the manual suggests removal of the biopsy port cap before cleaning and replacing it immediately before the next use. At the investigators' request, the STERIS device testing program performed pressure and flow studies with the biopsy port cap removed and observed a 50% flow reduction and a 25% flow pressure reduction. Therefore, STERIS could not assure bronchoscope sterility when the biopsy port cap was not replaced before processing, as specified in the STERIS manual.

Cluster 2

During March-April 1998, an increase in positive bronchial specimens for M. avium-intracellulare (MAI) occurred among patients in an ambulatory surgery unit (ASU) at a health-care facility. Seven cases without clinical evidence of MAI were identified over a 2-month period compared with two MAI cases during the preceding 8 months. All seven patients had undergone bronchoscopy in the same ASU with the same bronchoscope. Typing by polymerase chain reaction restriction enzyme analysis indicated that all of the isolates from the ASU bronchoscopy-associated patients were M. intracellulare (nontypable), and all of the isolates from the environmental and control patients with previously diagnosed atypical mycobacterial disease were M. avium. Mycobacterial cultures of the implicated bronchoscope, taken 12 days after diagnosis of the last MAI case, were negative.

The bronchoscope used was an Olympus BF-P20D model and was processed in a STERIS System 1. Olympus connectors were used for processing the bronchoscope in the STERIS System 1 rather than the connector kit and methods specifically developed by STERIS.

Cluster 3

During August-October 1998, 18 patients (11 inpatients and seven outpatients) at a health-care facility had bronchial specimens that grew imipenem-resistant P. aeruginosa (IRPA). None of the 18 patients had IRPA isolated from sputum cultures obtained before bronchoscopy. At least three patients had persistent infection with IRPA with an associated clinical illness postbronchoscopy. All but one of the isolates from the 18 patients had identical DNA patterns by pulsed-field gel electrophoresis analysis.

In July 1998, the facility began processing bronchoscopes and other endoscopes using a STERIS System 1 processor. The facility used Pentax (Pentax, Orangeburg, New York) and Olympus bronchoscopes but did not document the specific bronchoscope used on each patient. Neither the Pentax nor the Olympus bronchoscopes were connected to the STERIS System 1 in accordance with the STERIS manufacturer's recommendations. The person responsible for cleaning and disinfecting the endoscopes had received training at the STERIS Corporation; however, the specific scopes used at the facility were not demonstrated during the training.

Reported by: RL Stricof, MPH, MJ Oxtoby, MD, PF Smith, MD, State Epidemiologist, New York State Dept of Health. MA McGarry, Wadsworth Center, Albany; V Hay, W Rietsema, MD, N Rogers, S Segal-Maurer, MD, S Marks, JJ Rahal, MD, New York. G Prodhom, MD, Institute of Microbiology, Lausanne, Switzerland. Office of Surveillance and Biometrics, Center for Devices and Radiological Health, Food and Drug Administration. Hospital Infections Program, National Center for Infectious Diseases; and an EIS Officer, CDC.

Editorial Note:

The number of bronchoscopy procedures performed in the United States reached an estimated 497,000 in 1996 (1). Although reported infectious complications caused by bronchoscopy are rare (2), the incidence is probably underestimated, with many episodes unrecognized or unreported. Most reported bronchoscopy-related outbreaks or pseudo-outbreaks have been associated with inadequate cleaning and disinfection procedures (3-9).

The findings in this report identified additional problems related to using automated reprocessing machines. Conflicting recommendations for disinfection/ sterilization exist between bronchoscope and reprocessor system manufacturers. Some individual bronchoscope models are not compatible with certain automated reprocessing systems. However, users may not be aware of these incompatibilities unless they make a device-specific inquiry to the manufacturers. Personnel using automated reprocessing machines in these clusters did not receive adequate device-specific training, and the wrong set up or connector systems were used. Inadequate documentation in the third cluster about which bronchoscope was used in which patient prevented traceback of the culture-positive respiratory specimens to a particular bronchoscope.

Bronchoscopes are designed with small lumens, multiple ports with obtuse angles, and linings vulnerable to damage and subsequent biofilm formation, presenting obstacles to proper cleaning and disinfection or sterilization. Manual cleaning and sterilization with chemical agents, such as glutaraldehyde, is the reprocessing method most widely recommended by bronchoscopy equipment manufacturers; however, this process is laborious, time consuming, and poses a chemical contact risk to health-care workers. Thus, many health-care facilities use automated reprocessing machines. These machines can become colonized and cause bronchoscopy-related outbreaks or pseudo-outbreaks (5-8).

To address the challenges of reprocessing bronchoscopes, all users should comply with guidelines for cleaning and disinfection/sterilization (2,10). The following additional steps should be taken to reduce bronchoscopy-related infections or pseudo-infections. First, bronchoscope users should obtain and review model-specific reprocessing protocols from both bronchoscope and automated reprocessing system manufacturers. Second, bronchoscope and reprocessor system manufacturers should collaborate to develop and validate device- and model-specific high-level disinfection or sterilization protocols. Third, user education should include on-site training and observation during the set up of each bronchoscope model to clarify device- and model-specific differences in procedure. Fourth, instruction manuals provided by both bronchoscopy equipment and automated reprocessing system manufacturers should address procedural differences among varying models of bronchoscopes and highlight proper connector system(s) to be used with their machine. Fifth, connector systems should be clearly labeled (e.g., color coded) to ensure proper selection and use. Finally, quality-control procedures should be developed in each health-care facility to include visual inspection of the bronchoscope, regular testing for bronchoscope integrity, maintenance, and surveillance for unusual clusters of organisms.

Under the Safe Medical Devices Act of 1990, facilities are required to report to the Food and Drug Administration (FDA) instances when endoscopes (including bronchoscopes) and endoscope reprocessing systems may have caused or contributed to serious injury or a patient's death. Questions concerning this mandatory reporting requirement can be directed to FDA's Center for Devices and Radiological Health, Office of Surveillance and Biometrics, telephone (310) 827-0360. In addition, health-care workers are requested to report bronchoscopy-related colonization episodes, infection, or pseudoinfection to their state health department, to FDA's MedWatch program, telephone (800) 332-1088, fax (800) 332-0178, or World-Wide Web site,, and to CDC's Hospital Infections Program, telephone (404) 639-6413 or fax (404) 639-6459.


  1. CDC. Vital and health statistics: ambulatory and inpatient procedures in the United States, 1996. Hyattsville, Maryland: US Department of Health and Human Services, CDC, National Center for Health Statistics, 1998; DHHS publication no. 99-1710.
  2. Martin MA, Reichelderfer M. APIC guidelines for infection prevention and control in flexible endoscopy. Am J Infect Control 1994;22:19-38.
  3. Agerton T, Valway S, Gore B, et al. Transmission of a highly drug-resistant strain (strain W1) of Mycobacterium tuberculosis. JAMA 1997;278:1073-7.
  4. Bennett SN, Peterson DE, Johnson DR, et al. Bronchoscopy-associated Mycobacterium xenopi pseudoinfections. Am J Resp Crit Care Med 1994;150:245-50.
  5. Maloney S, Welbel S, Daves B, et al. Mycobacterium abscessus pseudoinfection traced to an automated endoscope washer: utility of epidemiologic and laboratory investigation. J Infect Dis 1994;169:1166-9.
  6. Gubler JG, Salfinger M, von Graevenitz A. Pseudoepidemic of nontuberculous mycobacteria due to a contaminated bronchoscope cleaning machine: report of an outbreak and review of the literature. Chest 1992;101:1245-9.
  7. Fraser VJ, Jones M, Murray PR, et al. Contamination of flexible fiberoptic bronchoscopes with Mycobacterium chelonae linked to an automated bronchoscope disinfection machine. Am Rev Resp Dis 1992;145:853-5.
  8. CDC. Nosocomial infection and pseudoinfection from contaminated endoscopes and bronchoscopes--Wisconsin and Missouri. MMWR 1991;40:675-8.
  9. Kaczmarek RG, Moore RM, McCrohan J, et al. Multi-state investigation of the actual disinfection/sterilization of endoscopes in health care facilities. Am J Med 1992;92:257-61.
  10. Garner JS, Favero MS. Guidelines for handwashing and hospital environmental control, 1985. Infect Control 1986;7:231-43.

* Use of trade names and commercial sources is for identification only and does not imply endorsement by CDC or the U.S. Department of Health and Human Services.

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