January 29, 2015 — A deadly ‘superbug’ infected at least 30 patients at a hospital in Seattle, Washington, between 2012 and 2014, with 11 of them dying, according to two news reports published last week.

This superbug is called carbapenem-resistant Enterobacteriaceae, or “CRE” for short, and is so named because members of this family of bacteria are resistant to most antibiotics including, as their name betrays, carbapenems, which are a “last resort” antibiotic.

Infections of CRE are particularly concerning, because some are associated with a mortality rate of as high as 50%.

And, whereas other types of bacteria transmitted during GI endoscopy can typically be eradicated with one or more types of antibiotics, some strains of CRE are resistant to all types of antibiotics (i.e., they are pan-resistant).

While this Washington hospital’s superbug outbreak may have contributed to the deaths of 11 patients (between 2012 and 2014), it was not until early in 2015 that those patients and their families impacted by this outbreak first learned of it.

CRE are a national concern

On January 21, 2015, USA TODAY reported that patients in U.S. hospitals undergoing a certain type of gastrointestinal (GI) endoscopic procedure known as “ERCP” (or, endoscopic retrograde cholangiopancreatography) may be at an increased risk of infection from CRE and related superbugs.

USA TODAY’s article discusses three separate superbug outbreaks identified between 2012 and 2013 at: (i) Advocate Lutheran General Hospital (Park Ridge, IL); (ii) University of Pittsburgh Medical Center – Presbyterian (Pittsburgh, PA); and (iii) Virginia Mason Medical Center (Seattle, WA).

Bearing a striking resemblance to one another, these three deadly outbreaks were each linked by investigators to a specialized type of GI endoscope called a side-viewing duodenoscope, which is sometimes also referred to as an “ERCP endoscope” because it is used to perform ERCP.

In each case, investigators confirmed that these GI endoscopes were contaminated with the outbreak’s strain of CRE (or another deadly and related superbug).

Infections not disclosed to patients

The next day, on January 22, 2015, The Seattle Times also published an article about infections of CRE linked to ERCP, focusing primarily on Virginia Mason Medical Center’s superbug outbreak, which began in 2012.

In total, at least 30 patients who had undergone ERCP at this hospital between 2012 and 2014 were infected with a deadly strain of either CRE or a related superbug, 11 of whom died.

This Seattle newspaper’s article reported for the first time that neither the hospital’s officials nor the Department of Public Health Public Health (Seattle and King County, Seattle, WA) — which, along with the federal Centers for Disease Control and Prevention (CDC), had assisted the hospital’s investigation of the cause and source of its CRE outbreak beginning in 2012 — informed the more than 30 impacted patients (and their families) that this deadly outbreak was the cause of their infections and may have contributed, at least in part, to 11 patient deaths.

A national discussion

These articles in The Seattle Times and USA TODAY have started a national discussion about not just the previously overlooked risk of superbug infections (with associated morbidity and mortality) linked to contaminated GI endoscopes, but also the responsibility that hospitals may have, if any, regarding the disclosure of an identified outbreak (or any type of medical error) to the infected patients, their families, and the community.

This Washington hospital’s CRE outbreak appears to be the most significant instance of disease transmission, with associated morbidity and mortality, ever linked to a GI endoscope. — Lawrence F Muscarella, PhD

A tale of three disclosures

Whether proper or not, Virginia Mason Medical Center’s decision not to notify its almost three dozen infected patients of the circumstances and nature (e.g., the cause, source, and clinical impact) of the superbug outbreak it linked to contaminated GI endoscopes used at the hospital between 2012 and 2014, not disclosing even that an outbreak had occurred and was responsible for their infections, is not unique.

For example, a local newspaper reported in April, 2014, that Children’s Hospital in New Orleans (LA) had not informed parents in 2008 and 2009 that a rare fungal outbreak had infected, and may have caused the deaths of, five of its young patients. This deadly outbreak was linked to contaminated bed linens.

And, like some of those infected during Virginia Mason Medical Center’s CRE outbreak, some of the parents of the children infected at this New Orleans hospital learned about this outbreak of mucormycosis, not from the hospital but almost six years later from newspaper reports — click here for more details.

In contrast, some hospitals prompt notify patients of a confirmed medical error as is urged by published codes of proper conduct, if not also the Hippocratic Oath.

For example, in 2014 Greenville Memorial Hospital (Greenville, SC) promptly notified impacted patients once it had linked an atypical mycobacterial outbreak following surgery to 15 patient infections and 4 deaths.

Click here to read Dr. Muscarella’s related article discussing this Greenville hospital’s atypical mycobacteria outbreak linked to contaminated tap water: “4th Patient Dies, 15 Infected at Greenville Memorial Hospital Linked to Contaminated Tap Water.”

An abstract published in October, 2014

In addition to the USA TODAY and The Seattle Times reports, some of the details of Virgina Mason Medical Center’s superbug outbreak are provided, if somewhat opaquely, in an abstract presented by the CDC at an infection control conference in Philadelphia, (PA) in October, 2014.

Other authors of this abstract include an official from the Department of Public Health Public Health – Seattle and King County, Seattle, WA:

Click here to read a copy of this abstract: “Endoscope-Associated Multidrug-Resistant Escherichia coli Outbreak — King County, Washington, 2012–2014.

A scientific article providing additional details of Virginia Mason Medical Center’s CRE outbreak beginning in 2012 is reputed to be published soon in the peer-reviewed literature.

A superbug outbreak

Virginia Mason Medical Center’s outbreak of CRE (and a related superbug) beginning in 2012 is remarkable for a number of reasons, not the least of which is because it is likely the most significant instance of the transmission of any infectious agent ever linked to a GI endoscope.

Moreover, with close to 3 dozen patients impacted, this superbug outbreak is one of the largest ever recorded, with 11 of the infected patients reportedly dying.

The first article to discuss this Washington hospital’s CRE outbreak (and from which the USA Today and The Seattle Times articles followed) was authored by Dr. Muscarella, appearing in this blog “Discussions in Infection Control” last December (2014).

That article by Dr. Muscarella provides additional details about Virginia Mason Medical Center’s superbug outbreak — click here to read: “BREAKING: At Least Seven More Deaths Linked to GI Endoscopes in Washington: A National Concern?

A national concern

As the USA TODAY article discusses, more than a dozen of these types of superbug outbreaks linked to contaminated GI endoscopes have been documented in the U.S. since 2008.[1,2]

Most of these outbreaks are listed in Dr. Muscarella’s peer-reviewed article “Risk of transmission of carbapenem-resistant Enterobacteriaceae (CRE) and related ‘superbugs’ during gastrointestinal endoscopy” — click here to read it.[2]

Endoscopic ultrasound: EUS

In addition to ERCP endoscopes, at least one published report confirms that a second type of GI endoscope is also prone to transmitting CRE.

Click here to read Dr. Muscarella’s related article about the aforementioned hospital in Pittsburgh (PA) that linked its CRE outbreak in 2012, not only to ERCP endoscopes, but also to EUS endoscopes: “A “Superbug” Outbreak Linked to Two Types of Gastrointestinal Endoscopes: Pennsylvania, 2012.

This second type of GI endoscope is called an “EUS endoscope,” because it used to perform endoscopic ultrasound (EUS). Like the ERCP endoscope, the EUS endoscope features a forceps elevator mechanism at its distal tip to control and manipulate accessories passed through the endoscope’s working channel.

Legal Reviews for Hospitals, Manufacturers, and Patients:  Click here to read about Dr. Muscarella’s expertise and legal assessments of the causes of healthcare-associated infections, including “superbug” outbreaks linked to contaminated GI endoscopes and other reusable medical equipment.

And, also like the ERCP endoscope, the EUS endoscope’s forceps mechanism reportedly is difficult to clean[3] and can remain contaminated with superbugs and other infectious organisms despite being reprocessed according to the instrument manufacturer’s published reprocessing instructions. (Note: The manufacturers of the implicated GI endoscopes may dispute this claim.)

FDA advisory: Is one forthcoming?

Whether concerns about infections of CRE associated with contaminated GI endoscopes, first documented in the U.S. in 2008,[1,2] have been understated and the risk of these types of infections all but overlooked is debatable.

No matter, to date, no state or federal health advisory, alert, or notice (or technical bulletin) has been issued either informing the public of the increased risk of superbug infections associated with contaminated GI endoscopes used during ERCP (and EUS), or advising GI endoscopy departments how to prevent the transmission of these nightmarish bacteria.

That said, the FDA is reputed to be publishing soon a public health notice discussing this risk and possibly providing guidance and recommendations.

This possibility that such an published advisory might be imminent is discussed in more detail in Dr. Muscarella’s article, “Superbugs, Contaminated Gastrointestinal Endoscopes, and a Growing Number of Hospital Infections: Is an FDA Action Imminent?” — click here to read it.


These recent outbreaks of CRE and related superbugs teach a number of lessons. Some of these lessons — click here — are provided in Dr. Muscarella’s related article, “Important Lessons Taught by Recent ‘Superbug’ Outbreaks Linked to GI Endoscopes.

In addition to teaching lessons, these documented outbreaks of CRE at hospitals around the U.S. since 2008,[1,2] among others that have not been publicly reported, raise a number of questions, most of which the FDA, ideally, will address in its forthcoming advisory about the risk of CRE transmissions during GI endoscopy.

These questions include:

  • Is there one single factor, or many, that is primarily responsible for these recent outbreaks of CRE following ERCP and EUS? 
  • Is there something about the design of GI endoscopes featuring an elevator mechanism that might hinder their thorough cleaning and high-level disinfection? Is a “quick fix” available?
  • What validated measures or corrective actions is the FDA recommending at this time to prevent a contaminated GI endoscope from transmitting CRE?
  • Could more enhanced, better manual cleaning of the GI endoscope be the key to the prevention of CRE outbreaks?
  • The CDC has reported that the use of ethylene oxide (EtO) gas sterilization to process ERCP endoscopes stopped at least one CRE outbreak. What explains this method’s apparent effectiveness? Are there other more feasible measures that might work as effectively, especially for a hospital that does not use EtO sterilization?
  • Has the FDA concluded that a change in the endoscope-reprocessing guidelines, or in the endoscope manufacturers’ written instructions, is necessary? Will the sterilization of ERCP endoscopes (in lieu of their high-level disinfection) be recommended in the future by the FDA to prevent CRE outbreaks?
  • What, if anything, can be done to enhance high-level disinfection’s effectiveness for reprocessing these implicated types of GI endoscopes? Might using a high-level disinfectant labeled for use at a relatively high temperature (e.g., 95o F or higher) prove to be as effective as EtO gas while being more convenient and cost-effective?
  • Might the delayed reprocessing of GI endoscopes have contributed to any of the documented outbreaks of CRE? Is the prompt reprocessing of GI endoscopes immediately following their clinical use all the more important?
  • What if the AER’s labeling suggests that the GI endoscope does not require manual cleaning before terminal high-level disinfection?  Whose instructions — the AER’s or the endoscope manufacturer’s — is the healthcare facility to follow, both to prevent outbreaks and to remain accredited for federal reimbursements?
  • What type of jurisdiction does the FDA have over hospitals? Can it require them to disclose identified CRE outbreaks, at least to the infected patients?
  • Has the FDA concluded that the microbiological sampling of GI endoscopes is necessary to confirm their safety? If so, what validated protocol should hospitals use?
  • Might “kits” that evaluate the GI endoscope’s channels for contamination with, for example, a protein (but not a bacterium) increase patient safety? Does the FDA consider these kits effective? Do these kits require a 510(k) clearance?
  • Has the FDA concluded that GI endoscopes might have been previously transmitting antibiotic-susceptible Enterobacteriaceae and other types of bacteria, but that these transmissions are only now wrecking havoc due to the CRE and other superbugs having become resistant to (and their infections no longer being masked by) strong antibiotics including carbapenems?

Ideally, the FDA’s forthcoming advisory will address and answer some, if not most, of these questions.


It would also seem that the FDA’s forthcoming advisory will likely give important guidance to healthcare practitioners and provide some specific recommendations for the prevention of CRE outbreaks following GI endoscopy (rather, possibly, than just expressing a general concern about this risk).

A review of the FDA’s advisory, once it is published, is urged.

Also recommended is the reader’s review of additional recommendations that Dr. Muscarella has provided for the prevention of the transmission of CRE and their related superbugs during GI endoscopy in some of his other related articles, including in the peer-reviewed article: “Risk of transmission of carbapenem-resistant Enterobacteriaceae and related ‘superbugs’ during gastrointestinal endoscopy”[2] — click here to download a copy (which is free, due in part to a generous educational grant provided by FujiFilm Endoscopy, USA, a manufacturer of GI endoscopes).


1. Alrabaa SF, et al. Early identification and control of carbapenemase-producing Klebsiella pneumoniae, originating from contaminated endoscopic equipment. American Journal of Infection Control 41 (2013) 562-4.

2. Muscarella LF. Risk of transmission of carbapenem-resistant Enterobacteriaceae (CRE) and related ‘superbugs’ during gastrointestinal endoscopy. World J Gastrointest Endosc 2014 October 16; 6(10): 457-474 — click here to read it.

3. Centers for Disease COntrol and Prevention. Notes from the field: New Delhi Metallo-β-Lactamase–Producing Escherichia coli Associated with Endoscopic Retrograde Cholangiopancreatography — Illinois, 2013. MMWR January 3, 2014;62(51):1051-1051 — click here to read this article.

Additional recommended reading

  • Muscarella LF. Alert: Association of GI Endoscopy with Two Patient Deaths: Illinois, 2013 — click here.
  • Muscarella LF. A ‘Superbug’ Outbreak Linked to Two Types of Gastrointestinal Endoscopes: Pennsylvania, 2012 — click here.
  • Muscarella LF. Important Lessons Taught by Recent “Superbug” Outbreaks Linked to GI Endoscopes — click here.
  • Muscarella LF. Overlooked Outbreaks of “CRE” Following GI Endoscopy: A “Superbug” Epidemic in Our Midst? — click here.
  • Muscarella LF. Investigation and Prevention of Bacterial Outbreaks following Endoscopic Retrograde Cholangiopancreatography, or ERCP — click here.
  • Muscarella LF. Superbugs, Contaminated Gastrointestinal Endoscopes, and a Growing Number of Hospital Infections: Is an FDA Action Imminent? — click here.
  • Muscarella LF. Risk of Transmission of Carbapenem-Resistant Enterobacteriaceae and Related “Superbugs” during Gastrointestinal Endoscopy. World J Gastrointest Endosc 2014 October 16; 6(10): 457-474 — click here.
  • Webpage: Superbugs and Endoscopyclick here.
  • Centers for Disease Control and Prevention (CDC). New Delhi Metallo-β-Lactamase–Producing Carbapenem-Resistant Escherichia coli Associated With Exposure to Duodenoscopes. Journal of the American Medical Association. October 8, 2014 — click here.
  • Centers for Disease Control and Prevention (CDC). Notes from the Field: New Delhi Metallo-β-Lactamase–Producing Escherichia coli Associated with Endoscopic Retrograde Cholangiopancreatography — Illinois, 2013. Morbidity and Mortality Weekly Report January 3, 2014;62(51); 1051-1051 — click here.
  • Medscape. CDC Confirms Superbug Transmission via Endoscopy. January 3, 2014.

By: Lawrence F Muscarella, PhD. Originally posted: 1/29/2015, Rev D.

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