• Waldenström Macroglobulinemia
  • Melanoma
  • Bladder Cancer
  • Brain Cancer
  • Breast Cancer
  • Childhood Cancers
  • Gastric Cancer
  • Gynecologic Cancer
  • Head & Neck Cancer
  • Immunotherapy
  • Kidney Cancer
  • Leukemia
  • Liver Cancer
  • Lung Cancer
  • Lymphoma Cancer
  • Mesothelioma
  • MPN
  • MDS
  • Myeloma
  • Prostate Cancer
  • Rare Cancers
  • Sarcoma
  • Skin Cancer
  • Testicular Cancer
  • Thyroid Cancer

Coming Clean: Protecting Yourself From Bacteria on Endoscopes

CURESpring 2020
Volume 19
Issue 2

Bacteria lingering on endoscopes can lead to drug-resistant infections. Before getting scoped, patients should ask how they will be protected.

When Bill Warner received a diagnosis of a possible bile duct tumor in December 2012, he underwent an endoscopic retrograde cholangiopancreatography (ERCP). This procedure uses a duodenoscope, a tubular, flexible endoscope with a light, camera and biopsy tools.

Doctors were unable to biopsy during several ERCP procedures, and after additional testing, he had surgery in February 2013 to remove and test part of the tumor in his liver. He and his wife, Carla Warner, breathed a sigh of relief when the results were benign. Their relief was short-lived.

Within a few weeks, Bill had a low-grade fever and didn’t feel well. Blood tests revealed carbapenem-resistant Enterobacteriaceae (CRE) bacteria.

“As the infection became stronger and stronger, he became weaker,” Carla says. The former concrete mixer driver lost 60 pounds over the next eight months and experienced weakness, delusions and “unbelievable pain,” she says. The only antibiotics that could treat the infection either caused kidney damage or made him vomit. Bill died from the infection in November 2013 at age 55.

CRE are, by definition, bacteria resistant to the carbapenem class of antibiotics, the last-resort treatment for severe infections. Mortality rates for those infected with CRE and related superbugs are up to 50%.

At the time, Carla and her husband’s doctors did not know how Bill had acquired the infection. Then, in spring 2015, while getting ready for work, she caught a morning television news segment that linked a child’s CRE infection to a duodenoscope used during ERCP. “His story was almost identical to ours. It was deja vu,” she says. Friends and family started texting: “Are you watching the news? Isn’t this what Bill had?”

Carla requested her husband’s medical records and found the duodenoscope maker and model. According to testimony before the Food and Drug Administration (FDA) and a 2015 Los Angeles Times story, the model used, an Olympus TJF-Q180V, was later associated with similar infections. It turned out that duodenoscopes from several manufacturers had designs that did not allow complete cleaning and disinfecting of tiny crevices in the movable elevator mechanism, even when medical centers followed manufacturers’ cleaning recommendations.

The FDA, researchers and device manufacturers are looking at updated disinfection or sterilization guidelines to minimize risks going forward, as well as design changes, such as manufacturers making disposable parts or instruments. The strategies vary in popularity and acceptance, with associated cost concerns.

Although CRE infections from duodenoscopes made the biggest news splash, other endoscopes have been associated with infection transmission, too, though to a lesser extent. Recent research in the journal Chest showed that bronchoscopes, inserted through the nose or mouth to inspect the lungs, may have a higher risk of transmitting superbugs like CRE or other multidrug-resistant organ- isms than previously thought. This seems to be connected to procedures used for reprocessing — disinfecting or sterilizing — the scopes. In certain circumstances, current reprocessing guidelines and instructions may not be enough to eliminate the low risk of transmission.

A handful of cases in 2016 linked gastroscopes, which are used to inspect the stomach, to superbug infections, and a few reports suggest that, although also a low risk, improperly reprocessed colonoscopes could expose patients to CRE infections, said Lawrence Muscarella, a consultant in quality improvement and health care safety who holds a doctorate in bioengineering and works with health care organizations and device manufacturers on causes of infection and prevention.

All of this poses a concern for those who have or had cancer and require repeated scoping. It also affects people predisposed to cancer who need ongoing surveillance, patients with unexplained gastrointestinal symptoms and those who simply get routine screening colonoscopies.

About half a million ERCPs are performed in the U.S. each year, and that’s just a fraction of 56 million upper endoscopies. In addition, 19 million colonoscopies are performed, according to an analysis conducted by iData Research.


“Any time there’s an invasive procedure, regardless of the type, there’s always a risk of bacterial translocation,” says Dr. Elizabeth Robilotti, an infectious disease specialist at Memorial Sloan Kettering Cancer Center. There are two ways to get an infection. The first, translocation, occurs when normally present bacteria move from their regular environment to another part of the body. Bacteria could travel from, say, the colon to the prostate during a transrectal prostate biopsy procedure or from the gut or skin into the blood, where there is no barrier to the development of infection. Although the risk exists, it’s exceedingly rare in healthy people, she says, and even rare in immuno- compromised individuals.

The other way to be infected is by acquiring someone else’s bacteria from an improperly reprocessed endoscope.

Remaining CRE bacteria are not inherently resistant to endoscopic cleaning, Robilotti says; rather, the cleaning process does not always allow full access to the instrument. “Cleaning

of the duodenoscope is a recognized challenge,” she says.

The bronchoscope’s design is less complex, but if the device is not properly serviced, it can pose a risk of transmitting CRE even when cleaned according to manufacturers’ instructions, Muscarella says.

A study he co-authored found that damage and inadequate maintenance were risk factors for bronchoscopes exposing patients to bacteria. Bacteria can be deposited in tiny cracks and tears, out of reach of cleaning processes, and grow in a resistant biofilm. The risk is low, and exposure does not guarantee infection, Muscarella adds.

The bacteria causing the CRE outbreaks were likely present in health care facilities before becoming drug-resistant, so infected patients received successful antibiotic treatment or recovered on their own. As recently as 20 years ago, bacteria like Klebsiella and E. coli, which today may be considered CRE, were susceptible to several types of antibiotics, according to Muscarella. “Transmissions may have been happening, but in the past, they were eradicated by the antibiotics or the patient’s own immune system,” he says.

The wide use of antibiotics and the constant development of new ones to address resistance has led to a long list of “superbugs.”


The chances of passing along bacteria on endoscopes can be reduced in several ways: repeating the disinfection, implementing sterilization or using partially or completely disposable endoscopes.

Disinfection: Flexible endoscopes are considered semicritical devices that normally come in contact with mucous membranes but not blood or otherwise sterile tissue. Although the FDA prefers that they be sterilized, it requires only disinfection. However, in spite of health care facilities following manufacturers’ directions for disinfecting flexible endoscopes, including duodenoscopes, the FDA reported in a 2018 study that up to 3% of duodenoscopes tested were considered reprocessing failures after being found positive for high-concern organisms, and up to 3% tested positive for low-concern organisms. The agency had expected a total failure rate of less than 0.4%. After cleaning with brushes and a detergent, high-level disinfection includes immersing an instrument in a liquid chemical germicide for the FDA-recommended amount of time, at the right concentration and temperature. The agency suggests repeating the process to ensure that it is done properly.

Sterilization: Some health care organizations are switching their protocol to sterilizing, instead of disinfecting, flexible endoscopes. When it comes to duodenoscopes, the FDA recommends sterilization over high-level disinfection when possible and practical, though availability of this method is limited. Sterilization can be difficult because the heat can damage components. One technique uses pressurized steam, but for more delicate instruments, organizations can use a low-temperature liquid chemical processing system, a sporicidal technology. Ethylene oxide gas is another sterilization option.

In 2018, North Dakota’s Altru Health System was the first to sterilize the duodenoscope. “I’m encouraged to know that there are some hospitals out there that are using sterilization (for these instruments),” Carla Warner says.

“If tested, these should not grow any type of bacteria or show any signs of leftover biomatter.”

Some hospitals may be reluctant to sterilize bronchoscopes or rigid endoscopes, Muscarella says, especially if the central reprocessing area is in the basement, requiring more careful tracking and monitoring of the instruments. When scopes are reprocessed closer to procedure rooms, they spend less time out of commission for cleaning, so the hospital can keep a lower inventory of them, he says.

Using sterilized equipment, even if not mandated by the FDA, can still be cost-effective, according to Carla. If hospitals realize that sterilization is a deciding factor for patients, they can highlight the practice in their advertising, she says.

Disposable Parts: To give duodenoscopes a safety update, the FDA recommends that health care systems transition to instruments with disposable components, such as end caps, or to fully disposable devices, allowing for more effective reprocessing or eliminating the need for it.

Currently, five manufacturers offer disposable end caps, and singleuse duodenoscopes are entering the market. The FDA approved a Boston Scientific model in December 2019. Disposable bronchoscopes are available, Muscarella says, but not widely used in the U.S.

One problem with disposable devices is cost and who pays it. The Boston Scientific single-use duodenoscope is expected to cost $3,000, and insurance coverage is not yet guaranteed, according to The New York Times. Hospitals already own reusable scopes at upward of $40,000 each. “(If insurance doesn’t cover a disposable scope,) the burden could shift onto the patient to decide whether to purchase it themselves, and that doesn’t typically happen in medicine,” Muscarella says.

If hospitals can’t negotiate the price, disposable instruments could be too expensive, he says.

Other concerns with disposable scopes include reuse for economic reasons. Inexpensive disposable equipment is discarded, Muscarella says, but there could be a financial incentive to reuse costly single-use devices, which is counter to their purpose. Also, disposable scopes would not prevent infections caused by bacteria’s movement from one part of the body to another. “The infection rate is not entirely eliminated by single-use endoscopes, but clearly, it would prevent patient-to-patient trans- mission,” Muscarella says.


Patients don’t always know what to ask their doctors regarding recommended endoscopies.

When Carla had to schedule a spinal fusion after her husband died, she asked the doctor to explain each step from beginning to end, telling her how every item in the operating room would be reprocessed, which ones would have been sterilized, and which would be new or unused. “He was a little taken aback by the question, and it was something he had not discussed with a lot of patients,” she says. She also asked why he chose to work at that hospital.

When he said it was because of lower infection rates, she was satisfied. After she shared her reasons for asking such detailed questions, the doctor said, “I should be having this discussion with all my patients.”

Carla recommends also asking about the equipment and model numbers, steps taken to clean the endoscopes, whether the scopes are sterilized or disinfected, and whether they are inspected with a borescope, a small instrument that helps detect tears and defects that can harbor bacteria. Not all physicians understand how reprocessing works because they are involved only with the procedure, but Carla encourages physicians to visit the central reprocessing area to learn. “The first red flag for me is if a physician can’t tell me the steps, they take to make sure the patient is safe,” she says. If the medical staff, including the receptionist, do not take concerns seriously and provide answers, patients should find a new doctor or facility, she says.

Muscarella agrees that patients have some control and power because they can decide where to have procedures done. They can tell doctors or clinics that they plan to call several facilities and choose the one that best meets their requirements. For instance, patients could look for a facility with a robust safety program, which could include using a certain type of endoscope or sterilizing instruments instead of disinfecting them.

These conversations are one positive result of the infection outbreaks, says Andrea Dwyer, director of the Colorado Colorectal Screening Program and adviser to the patient advocacy group Fight Colorectal Cancer. In addition to asking about procedure risk, “it’s OK to ask how many procedures the doctor does per year, the volume — and, if something happens, how to follow up and who to follow up with,” she says.


Infection following an endoscopic procedure could occur within 24 hours or longer, says Robilotti. During diagnosis, doctors consider the severity of the illness and may test for infection in multiple sites, such as blood, urine and possibly bile, if a bile drain is involved. “We have to put the whole clinical picture together to establish if certain signs or symptoms are from an infection,” he says, and, if so, where it arose.

Determining causality is important. If a patient develops an infection but does not inform the doctor who performed the endoscopy or tell the doctor treating the infection about prior procedures, the doctors may not connect the dots. One remedy is for the doctor’s office or clinic to contact patients after the procedure and ask if they have any infection symptoms. “The FDA is reporting reduced infection rates,” Muscarella says, “but if the medical facility doesn’t track all infections, then the risk could be underreported.”

The risk of getting an infection from a diagnostic procedure is real. But when a doctor recommends an endoscopy, it’s important to consider the risk versus benefit, Dwyer says. Colonoscopies, for example, carry a small risk of complications but a high rate of effectiveness for identifying potentially cancerous polyps.

In spite of her husband’s death from the CRE infection, “I will never advocate for someone to go against what their physician recommends they need in treatment,” Carla says. What if her own doctor recommended an ERCP?

“I wouldn’t say I would not do the procedure,” she says. “I’d have to do my research really well. If I couldn’t find a satisfactory local provider, I’d go somewhere else that has technologies available for true sterilization.”