August 3, 2015 — Not just duodenoscopes, but also EUS endoscopes, bronchoscopes, and urological instrumentation used during endoscopy pose a risk of infecting patients with multidrug-resistant bacteria, including CRE, my research has found.

Contaminated bronchoscopes pose a risk of infecting patients in U.S. hospitals with the deadly “superbug” that has come to be known as CRE, or carbapenem-resistant Enterobacteriaceae, according to an article by Dr. Muscarella published two weeks ago, in July, in “Discussions in Infection Control.”

Dr. Muscarella’s July 2015 article reveals publicly that, despite statements by health officials to the contrary, a duodenoscope is not the only type of flexible endoscope used in the U.S. that poses a demonstrated risk of transmitting CRE infections.

Update:  The FDA appears to have appreciated this article’s focus on bronchoscopes. One month after the original publication of this article in August, 2015 — which informed the public that contaminated bronchoscopes and urological instruments, like duodenoscopes, also have been linked to potentially deadly ‘superbug’ outbreaks — the FDA published a safety communication on September 18, 2015, entitled: “Infections Associated with Reprocessed Flexible Bronchoscopes: FDA Safety Communication.”

Duodenoscopes are used to perform endoscopic retrograde cholangiopancreatography, the gastrointestinal procedure better known as “ERCP.”  Bronchoscopes, on the other hand, are used during pulmonary applications to diagnose and treat diseases of the lungs.

A report filed by an endoscope manufacturer in December 2014 links a bronchoscope to a potential superbug outbreak. So, it appears that duodenoscopes are not the only type of flexible endoscope that poses a risk of infecting patients with CRE. — Lawrence F Muscarella PhD

Carbapenems are a class of antibiotics used to treat serious healthcare-associated infections. Bacteria that are resistant to carbapenems are growing in number, posing concerns for public health officials.

The Los Angeles Times

Apparently appreciating and agreeing with Dr. Muscarella’s July 2015 article, the Los Angeles Times published a front-page article this past weekend (August 2, 2015) reporting that which Dr. Muscarella had two weeks earlier, but public health officials have not: that bronchoscopes may infect patients with deadly CRE.

This Times’ article is entitled, “Variety of medical scopes pose the risk of serious infection” (The Los Angeles Times, August 3, 2015).

What this newspaper reported that’s new to the public, however, is that cystoscopes, too, may pose a risk of superbug infections. These are endoscopic instruments used to examine, diagnose and treat diseases of the bladder.

Update, Breaking — Cited in The Washington Post, also read Dr. Muscarella’s other article discussing the link between bronchoscopes and ‘superbug’ outbreaks: “Contaminated Bronchoscopes Linked in 2014 to A Potential ‘Superbug’ Outbreak: An Under-recognized Risk?” (August, 2015)

The Food and Drug Administration (FDA)

To date, the FDA has suggested that only gastrointestinal endoscopes — namely, duodenoscopes and, to a lesser extent, linear echo-endoscopes, both of which are gastrointestinal endoscopes that feature a forceps elevator mechanism — pose a risk of transmitting CRE to patients.

Linear echo-endoscopes are used to perform endoscopic ultrasound, or “EUS.”

Indeed, the focus and emphasis of several FDA safety communications published during the past few months, beginning in February, 2015, were to publicize that only certain types of gastrointestinal endoscopes featuring an elevator forceps mechanism, primarily duodenoscopes, pose a risk of infecting patients with CRE.

An elevator forceps mechanism is a lever, located at the duodenoscope’s distal tip, that is used by the physician during ERCP to control the direction of certain types of accessories devices, such as cannulae and needles.

But, unlike duodenoscopes, bronchoscopes do not feature a forceps elevator mechanism, which the FDA has concluded can be challenging to clean and the primary cause of the association between duodenoscopes and CRE outbreaks.

Bronchoscopes are much simpler in design and easier to clean than gastrointestinal endoscopes, especially duodenoscopes.

To prevent confusion and reduce the risk of patient harm, it may now be warranted for the FDA to issue a safety notice notifying the public that CRE outbreaks appear not to be limited to contaminated duodenoscopes, but may also include other types of flexible endoscopes, including bronchoscopes, that lack a forceps elevator mechanism. — Lawrence F Muscarella PhD

The Centers for Disease Control and Prevention (CDC)

Nor have federal health officials at the Centers for Disease Control and Prevention (CDC) publicly expressed a concern that other types of flexible endoscopes, including bronchoscopes may also be prone to contamination with CRE even after cleaning.

Instead, the CDC wrote that its recent surveillance protocol is “intended for facilities that perform procedures using duodenoscopes,” adding that “while these (sampling) measures apply primarily for duodenoscopes, they can also be implemented for other flexible endoscopes that have an elevator mechanism.”

The CDC published this protocol earlier this year, in March, to assess the effectiveness of a reprocessing procedure and to detect CRE on an endoscopes

Whether the CDC now endorses the use of its surveillance protocol to detect CRE inside bronchoscopes and other types of flexible endoscopes not featuring a forceps elevator mechanism is unclear. — Lawrence F Muscarella PhD

A medical device report (MDR)

As Dr. Muscarella publicly reported for the first time, an endoscope manufacturer filed a medical device report, or MDR, in December 2014 documenting that contaminated bronchoscopes can, too, transmit deadly infections of CRE.

According to this manufacturer’s report, 14 patients tested “positive” for a carbapenem-resistant strain of Klebsiella pneumoniae following bronchoscopy. This bacteria is a potentially deadly type of CRE.

This report further explains that an Olympus BF-160 model remained contaminated with CRE after repeated reprocessing. This report also states that the bronchoscope had been repaired by a third-party vendor. The endoscope was removed from service.

According to the August Los Angeles Times article, this filed MDR was the third report in less than as many weeks linking an Olympus bronchoscope to a suspected outbreak.

In at least one of these outbreaks, the Los Angles Times reports that “a nurse reported that three people were sickened by another often deadly bacteria.” (Whether other manufacturers’ bronchoscopes have also been linked to similar outbreaks of CRE following bronchoscopy is unclear.)


The Los Angeles Times’ August article raises important concerns about the risk of contaminated cystoscopes transmitting deadly CRE and related superbugs in U.S. hospitals.

According to the Times, cystoscopes have also been found to remain soiled with potentially infectious debris after cleaning. Like bronchoscopes, cystoscopes do not feature a forceps elevator mechanism.

Dr. Muscarella had discussed a concern about cystoscopes transmitting CRE last year in his 2014 peer-reviewed article, “Risk of transmission of carbapenem-resistant Enterobacteriaceae and related ‘superbugs’ during gastrointestinal endoscopy.”

Quality and Safety Services and Case Reviews for Hospitals, Manufacturers, Patients: The CDC’s recent safety alert stresses that a healthcare professional “with expertise in device reprocessing” should immediately assess a healthcare facility’s reprocessing procedures. Click here to read about Dr. Muscarella’s quality and safety services and comply with this safety alert.”

Possible causes? 

While no media source including The Los Angeles Times has yet reported the potential causes of bronchoscopes (and cystoscopes) possibly transmitting CRE, Dr. Muscarella has previously published that the following two factors, among others, may play a role:

1. The lack of effective measures to detect, preemptively and reliably, when the bronchoscope’s internal channels have become worn, torn, or otherwise damaged requiring servicing and repair, not only to ensure the endoscope’s proper operation, but also to prevent infections, including CRE outbreaks. Whether a contributor to these outbreaks may be the use of internal channel tubing materials whose quality is not ideal is unclear; and

2. Perhaps, the hospital’s utilization of a “leak test” during the cleaning process that may not be sufficiently sensitive to detect all types of tears and damage to the bronchoscope. Transmissible bacteria may be retained in these tears and resulting crevices, and become dislodged during bronchoscopy, resulting in CRE outbreaks.

The Los Angeles Times’ August article reports that the endoscope’s manufacturer “did not respond to requests for comment” when asked about its filed MDR, which indicates that bronchoscopes, too, may transmit deadly CRE infections.

The Los Angeles Times also reports in this article that, for its part, the FDA “believes the scopes currently on the market are safe.”

Four types of endoscopes linked to CRE outbreaks

Dr. Muscarella’s research suggests that each of the following types of endoscopes and associated instrumentation poses a risk of transmitting multidrug-resistant bacteria, including CRE, to patients:

  • duodenoscopes (used during ERCP)
  • linear echo-endoscopes (used during endoscopic ultrasound or “EUS”)
  • bronchoscopes
  • cystoscopes and associated urological instrumentation

While the FDA has focused its safety communications in 2015 on warning the public about the risk of CRE outbreaks associated with the use of only the first two types of gastrointestinal endoscopes, bronchoscopes and cystoscopes, too, appear to pose a similar risk.

Centers for Medicaid and Medicare Services (CMS)

On August 4, the FDA published the document “Supplemental Measures to Enhance Duodenoscope Reprocessing: FDA Safety Communication,” noting that the agency is “collaborating with the Centers for Medicaid and Medicare Services (CMS) and The Joint Commission to strengthen health care facility adherence to duodenoscope reprocessing instructions.”

Whether accreditation surveys performed on behalf of the CMS are adequately robust and committed, first, to identify infection control breaches that might result in CRE infections; and, second, to sanction facilities deemed not to be in compliance with CMS’s infection control regulations is unclear.

It is possible that significant improvements in this federal program overseeing the inspection of a participating hospital’s safety might significantly reduce the risk of superbug infections as well as healthcare costs.

Despite the high, and still growing, number of healthcare-associated infections in U.S. hospitals, remarkably, less than 1% of participating U.S. hospitals lose accreditation, which deems them no longer eligible to receive Medicare payments.

Closing remarks

It is recommended that the FDA consider issuing safety alerts:

— notifying hospitals and the public that the risk of CRE outbreaks are not limited only to duodenoscopes, but also include other types of flexible endoscopes, including and echo-endoscopes, bronchoscopes and cystoscopes; and

— advising hospitals to consider applying the four supplement measures that the FDA first published in August 2015 to improve the safety of duodenoscopes also to echo-endoscopes featuring an elevator forceps mechanism.

An FDA statement addressing the safety and effectiveness of automated endoscope reprocessors, or AERs, for disinfecting flexible endoscopes potentially contaminated with CRE might also be warranted to reduce the risk of patient harm.

The FDA has provided little advice about the adequacy and validation of some models of AERs for reprocessing flexible endoscopes contaminated with CRE, such as the Olympus TJF-Q180V duodenoscope, which, to date, has not been cleared by the FDA.

Article by: Lawrence F Muscarella, PhD; posted: August 4, 2015. Updated: September 18, 2015, Rev A.

Note: Dr. Muscarella is the president of LFM Healthcare Solutions, LLC, an independent quality improvement company. Click here for a discussion of his quality improvement healthcare services.

One thought on “Four Types of Medical Endoscopes Now Linked to Deadly ‘Superbug’ Infections”
  1. Dear Dr. Muscarella.

    I am amazed every time when I am reading these reports and the FDA & CDC reactions as they all ignore the fact that in Endoscopy “it takes 2 to tango” it’s the endoscope and the AER or the reprocessing method. As we can see although the CRE was there for several years now the number of outbreaks seams to suddenly grow during the last 3 years the question should be what has changed? The scopes are the same scopes, the bugs are the same bugs, the AERs are the only ones that supposedly “evolved” into the new generation that employ the “modified manual cleaning” or the “no need for cleaning” claims. These new claims have never been tested in real clinical environment, before FDA approval, they were tested on a simulator tubing with a simulating artificial organic contamination which are different form real life clinical conditions. These events should be a wakeup call to manufacturers and regulators to remember the basic truth that any change in the cleaning process will eventually compromise the HLD stage and increase the risk of cross infection.

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