Superbug found in Phila. now in L.A.; FDA acts

This illustration depicts a three-dimensional computer-generated image of a group of carbapenem-resistant Enterobacteriaceae bacteria. (AP Photo/Centers for Disease Control)

Following outbreaks in Philadelphia, Seattle, and elsewhere, a Los Angeles hospital has been struck by drug-resistant "superbugs" that were linked to a special kind of hard-to-clean endoscope and played a role in two deaths.

On Thursday, the Food and Drug Administration issued a safety warning about the complex devices, called duodenoscopes, urging hospitals to take precautions but saying that effective cleaning of certain internal mechanisms "may not be possible."

Ronald Reagan UCLA Medical Center reported that seven patients had tested positive for the drug-resistant bacteria after undergoing a procedure with one of the $40,000 scopes, and that as many as 179 people had been exposed.

A Philadelphia hospital was struck by a similar outbreak in 2014, according to the city Department of Public Health. Eight patients examined with the scopes became infected with drug-resistant bacteria and two died, though officials said the deaths were "not clearly related" to the infection.

The department has declined to identify the hospital, saying it did not want adverse publicity to discourage reporting of future cases.

Other clusters of cases have been reported in Seattle, Pittsburgh, and the Chicago suburb of Park Ridge.

The outbreaks have physicians trying to balance the need to administer a vital medical procedure to people who are generally quite sick against the challenge of trying not to make them sicker.

Duodenoscopes are used in more than 500,000 procedures a year in the United States, including the draining of bile and pancreatic ducts that are blocked by tumors or gallstones, the FDA said.

Several species of bacteria have been identified in the outbreaks, but all have one thing in common: They are resistant to a class of last-resort antibiotics called carbapenems.

Once a microbe has developed resistance to those drugs, about the only thing left in a physician's arsenal is a detergentlike antibiotic that may kill the bacteria, but also destroys the patient's kidney cells, said Neil O. Fishman, an infectious-diseases specialist at the Hospital of the University of Pennsylvania.

Healthy people can often fight off the bug on their own. But for those with chronic illness, it is bad news.

In its new "safety communication," the FDA said that in addition to following manufacturers' reprocessing instructions, hospitals should "meticulously clean" the device's internal mechanism. The agency further urged prompt consultation with a doctor by any patients who are treated with the device and go on to develop fever, chills, or nausea.

Some hospitals, such as UPMC Presbyterian Hospital in Pittsburgh, have taken the additional step of sterilizing the scopes with a gas called ethylene oxide. That process takes 18 hours, rather than the one or two required for the regular cleaning process recommended by manufacturers.

To make sure it always has enough on hand, UPMC purchased a dozen additional duodenoscopes, doubling its inventory, said Carlene Muto, the hospital's director of infection prevention.

It began gas sterilization after identifying 18 infected patients in 2012, of which nine had undergone an examination with one of the endoscopes. Further examination showed that only one of the infections appeared to be transmitted via the scope; the others were acquired outside the hospital, a spokeswoman said.

Muto said no new cases had been found at UPMC Presbyterian since the new sterilization method was adopted.

Penn's Fishman said his health system had no plans to use gas, but had enhanced its manual cleaning regimen and had not seen any infections transmitted by the scopes.

More evidence is needed before the gas sterilization method can be recommended for everyone, said Chris Lavanchy, engineering director at the ECRI Institute, a Plymouth Meeting-based nonprofit that evaluates medical devices. One issue is the requirement for proper ventilation to protect the technicians who use it.

ECRI is studying the scopes and plans to issue its own recommendations, possibly involving testing the devices for bacteria after each cleaning, Lavanchy said.

Biomedical engineer Lawrence Muscarella, an infection-control consultant based in Montgomeryville, said Thursday's communication from the FDA was a step in the right direction, but not enough.

"I think the only true way to solve this is through enhancing the design of the device," Muscarella said.

Among the manufacturers of duodenoscopes are Fujifilm, Pentax Medical, and Olympus, all of which have said they are working with the FDA on solutions.

 


tavril@phillynews.com

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