Could a simple plastic sheath have prevented the UCLA superbug outbreak?

The answer to the question posed in the headline is, in theory, yes. The reality is a bit more complicated.

A type of endoscope contaminated with carbapenem-resistant enterobacteriaceae (CRE) has contributed to the death of two people who were treated at the UCLA Ronald Reagan Medical Center, with 179 patients possibly exposed to the antibiotic-resistant superbug, as reported last month in PlasticsToday. The first of what will probably be several lawsuits was filed on Feb. 23 by Aaron Young, who contends that the Q180V scope manufactured by Olympus that was used in the procedure included a safety cleaning protocol for an older design of the device. That cleaning process wasn't effective in removing all residual body fluids and organic debris, alleges Young.

Whether or not Olympus was negligent will be decided by the courts. It is one of three medical device manufacturers—the others are Fujifilm and Pentax—that manufacture this specialized endoscope, called an endoscopic retrograde cholangiopancreatography (ERCP) duodenoscope. The design of the device, which includes what FDA calls a "movable ‘elevator' mechanism...[that] changes the angle of the accessory exiting the accessory channel," makes it difficult to clean thoroughly. According to news reports, medical personnel at UCLA followed the cleaning procedure recommended by the manufacturer. However, the narrow channels and ports in endoscopes are hard to reach and disinfect, making it extremely difficult to remove 100% of microbes. The mechanism of the duodenoscope adds to this complexity. One solution that is used on some endoscopes to prevent potential contamination is a single-use plastic sheath.

The risk of acquiring a deadly infection in your doctor's office or a surgery center can be reduced to practically zero with [a] simple . . . technology that is already available, writes Steve Brozak on forbes.com. "Scopes used for the urinary tract, lungs, esophagus and throat are now on the market that are designed to fit into specially-made protective sheaths." The sheath, which is used once and then discarded, prevents the scope from coming into contact with the patient. "An infection has never been traced back to a sheathed endoscope," adds Brozak.

Unfortunately, there is currently no magic bullet for duodenoscopes. Vision Sciences, which is behind EndoSheath technology, does not make a sheath appropriate for a duodenoscope at this time, reports Marie Thibault on mddionline.com. "I'd be surprised if there wasn't a certain level of [regulatory] action associated with either design or reprocessing requirements," Christian Escobar, Director of Marketing at Vision Sciences, told Thibault. "All scopes, not just ERCP duodenoscopes, are difficult to clean and we're looking to solve the problem through design," he says.

One could also posit that the complexity of the duodenoscope presents certain challenges for designing an appropriate sheath. And while a plastic protector sounds simple in theory, in this application it is quite complex. Notably, as Brozak points out, the sheath "is actually a very sophisticated piece of equipment, as it has a lens that precisely covers the lens of the camera tip, so image preservation is seamlessly maintained."

While it's no solace to infected patients from the UCLA medical center and elsewhere—there have been other major outbreaks over the last few years—ECRP, if called for, is still better than the alternatives. The duodenoscope allows physicians to examine and treat conditions related to the pancreas and biliary system that, otherwise, would require open surgery. In some cases, the choice is between ECRP and not treating the condition at all. In the wake of the outbreak, medical establishments have instituted disinfection procedures that go above and beyond what the manufacturer and FDA recommend. Can they guarantee that the devices are 100% free of contaminants in all circumstances? Probably not.

Disposable sheaths seem to be the most effective defense against another outbreak but, as noted above, none are available for duodenoscopes. In the meantime, perhaps the best, if somewhat cynical, advice to patients undergoing this procedure is, as Judy Stone writes on forbes.com, the "old adage among many health care workers [that] it is better to be the first patient of the day."

Norbert Sparrow

Norbert Sparrow is Senior Editor at PlasticsToday. Follow him on twitter @norbertcsparrow and Google+.

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