Deadly bacteria on medical scopes trigger infections

Peter Eisler | USA TODAY

Show Caption Hide Caption CRE infection linked to medical device design A deadly bacteria linked to a commonly used medical device. Jean Enersen reports.

Editor's note: This story originally was published January 21, 2015, at 6:21 p.m. EST. It has been updated to add video and links.

The deadly pattern of illnesses began to emerge in 2012 at hospitals in Seattle, Pittsburgh, Chicago. In each case, the culprit was a bacteria known as CRE, perhaps the most feared of superbugs, because it resists even "last defense" antibiotics — and kills up to 40% of the people it infects.

And in each case, investigators identified the same source of transmission: a specialized endoscope, threaded down the throat of a half-million patients a year to treat gallstones, cancers and other disorders of the digestive system. They found that the devices, often called duodenoscopes, accumulate bacteria that are not always removed by conventional cleaning, so infections can pass from patient to patient.

Yet neither the scopes' manufacturers nor the Food and Drug Administration, which regulates them, have publicized or offered guidance on the problem. So, many doctors who use the scopes — and most of the patients they treat — don't know the risks. Nor do they know that steps can be taken to cut those risks dramatically.

"Most hospitals that do these procedures are not even looking for this problem, or they may not be aware, and that's got to change," says Jeffrey Duchin, a physician who heads communicable disease control at the Seattle and King County (Wash.) Public Health Department.

Many of the resulting infections may go unnoticed, says Duchin, who directed the investigation of the CRE outbreak in Seattle. In that case, seven patients died with infections that were associated with contaminated duodenoscopes; five of them with CRE. (None of the deaths was attributed solely to the infections because all of the patients also had other health problems.)

When contaminated scopes transmit CRE, it's likely to get attention, because the infections involve especially perilous, "red-flag" bacteria, Duchin says. But more common bugs may elicit little more than a quick prescription for antibiotics — and no investigation.

"There's a likelihood that we're just seeing a very small subset of the universe of infections from these types of scopes," Duchin says.

The FDA says in a written statement to USA TODAY that it is "aware of and closely monitoring" the infection risks associated with the scopes. "Some parts of the scopes may be extremely difficult to access and clean thoroughly," the agency adds, "and effective cleaning of all areas of the duodenoscope may not be possible."

The agency is studying the problem and working with manufacturers to determine whether new cleaning protocols should be mandated or the scopes should be redesigned entirely. Meanwhile, the scopes' "lifesaving" ability to detect and treat potentially fatal digestive disorders outweighs their infection risks, the statement adds. "It (is) important for these devices to remain available."

Few dispute the scopes' importance. But public health officials and endoscopy experts who have studied the problem believe the FDA and scope manufacturers have been slow to bring attention to the infection risks and publicize steps hospitals can take to reduce them dramatically.

"It's fair to ask whether the FDA could have been doing more to regulate these devices and significantly reduce the risk of patient harm," says Lawrence Muscarella, a biomedical engineer and independent consultant who advises hospitals on endoscope safety. "Patients have died, and the agency seems to be moving slowly."

DIRTY SCOPES, DEAD PATIENTS

Muscarella has identified at least a half-dozen U.S. outbreaks of CRE and related superbugs since 2012 that were linked to contaminated duodenoscopes — findings he published in a peer-reviewed medical journal in October. The biggest cases involved dozens of patients and multiple deaths, but as in the Seattle outbreak, not all of the fatalities were attributed conclusively to CRE because some patients had multiple ailments.

Most of the patients had undergone a procedure known as ERCP, or endoscopic retrograde cholangiopancreatography. In the procedure, the duodenoscope is used to inject a contrast dye into the bile and pancreatic ducts, of which X-rays are taken to reveal blockages, tumors, gallstones and other problems.

The scope also can be used to gather material for biopsies, remove stones or other obstructions, or install stents to open the ducts.

Last year, after linking the CRE outbreak in Chicago to ERCP scopes, the Centers for Disease Control and Prevention issued a warning about the risks of spreading infections among patients who undergo the procedure. The problem, investigators found, is that biological material can collect in the "elevator" mechanisms that control tiny devices that extend from the tip of the duodenoscope.

Even when the devices are cleaned strictly in accordance with manufacturers' FDA-approved guidelines, "they have a lot of intricate mechanisms and pieces that are very difficult to disinfect," says Alex Kallen, an infectious-disease physician at the CDC who helped direct the investigation. "There definitely is a risk of (disease) transmission with these scopes."

NOT WAITING FOR FDA

Several hospitals that have linked CRE outbreaks to their duodenoscopes have not waited for guidance from the FDA and scope manufacturers; they've developed new safety procedures on their own that are showing great promise.

At Virginia Mason Medical Center in Seattle, officials adopted new scope-cleaning protocols and now require that all scopes be quarantined after cleaning, then tested for any residual bacteria before they can be reused.

The hospital had to purchase additional scopes, and more staff were needed for cleaning and testing, according to Duchin, the county health official. He says the changes cost the hospital an estimated $1 million, but the investment paid off: No infections have been linked to the scopes since the new procedures were put in place.

At University of Pittsburgh Medical Center and Advocate Lutheran General Hospital outside Chicago, officials have begun using a process called EtO gas sterilization to ensure that any bacteria lingering on scopes after manual cleaning are destroyed. The process requires special facilities and equipment because the gas is toxic, but the hospitals have reported seeing no infections since they began using it.

Both the gas sterilization and the quarantine-and-test approaches would be difficult for many hospitals to adopt — particularly those that have smaller staffs and budgets, says Marcia Patrick, a member of the education faculty with the Association for Professionals in Infection Control and Epidemiology.

But Patrick notes that there are things that most hospitals can do to at least assess their risks for transmitting CRE and other infections through scopes. For example, she says, hospitals should consider taking bacterial cultures from scopes on occasion to assess whether their disinfection processes are working.

"The cost of culturing is not that high," Patrick says. "You can culture them once, see what's there, and based on that, maybe do it once a month for surveillance."

REGULATORY ISSUES

The FDA says it is working with all three major manufacturers of duodenoscopes — Olympus, FUJIFILM and Pentax — to assess potential design changes and determine whether new disinfection processes can ensure the scopes' safety in their current configuration.

The agency says it also is looking at whether new disinfection processes might be adaptable to ensure safety of all types of reusable endoscopes, since many hospitals process different scopes in batches. Ensuring duodenoscope safety "is on the agency's priority list for guidance documents we intend to publish in 2015," the FDA statement says.

In separate statements to USA TODAY, all three manufacturers said they are aware of the concerns about infection transmission from their duodenoscopes and are working with FDA to address the issue. All three noted that proper cleaning of the devices according to existing, FDA-approved guidance would help minimize infection risks.

The extent of that risk remains an open question, because infections linked to duodenoscopes can be difficult to detect. Muscarella and other experts say large numbers of cases likely go unreported.

CRE infections get noticed because they're so deadly and hard to treat. The bacteria are formally titled Carbapenem-Resistant Enterobacteriaceae for their resistance to carbapenem antibiotics — the last line of defense in the medical toolbox. They generate particular concern because CRE's resistance gene can transfer to other bacteria, transforming more routine bacterial infections into drug-resistant scourges.

But Muscarella, Patrick and others note that duodenoscopes are almost certainly transmitting other, less serious infections as well. Those cases tend to go unnoticed, they say, because doctors simply prescribe antibiotics and don't give much thought to where or how the illness was contracted.

RAISING AWARENESS

The reported cases of CRE are "probably the tip of an iceberg" of infections transmitted by duodenoscopes, Patrick says. "But we don't know how big that iceberg is."

All patient illnesses or injuries linked to a medical device are supposed to be reported to the FDA by hospitals and manufacturers. But the agency concedes in its statement that those reports can be spotty, as many infections are not linked back to their cause.

The FDA says it is considering whether to require that hospitals do the sort of periodic bacterial testing of duodenoscopes that some infection experts see as necessary. In addition to helping hospitals gauge the efficacy of their disinfection practices, such a rule could provide more data on the scopes' infection risks.

In the meantime, efforts to raise awareness of the problem are limited mainly to a few medical journal articles, the CDC's alerts and information put out by physicians' groups and medical societies.

"This is a very important issue," says Bret Petersen, a physician who serves as a counselor and board member at the American Society for Gastrointestinal Endoscopy. The society has sent alerts to members about the infection risks associated with duodenoscopes, Petersen says, but it has not endorsed specific disinfection recommendations because the steps taken by affected hospitals have not been validated by the FDA.

"We do expect the FDA and the manufacturers to provide additional public guidance," he adds.