All three manufacturers of duodenoscopes linked to recent outbreaks of antibiotic-resistant “superbug” infections redesigned the devices in recent years to make them easier to clean, but the changes likely created new ways for the potentially deadly bacteria to survive sterilization and disinfecting processes.
In the last two years, patients have become infected with antibiotic resistant bacteria after undergoing duodenoscope procedures at hospitals in California, Connecticut, Illinois, Pennsylvania, and Washington.
At Ronald Reagan UCLA Medical Center, duodenoscopes infected with Carbapenem-resistant Enterobacteriaceae (CRE) have sickened seven patients since October and caused the deaths of at least two of them. Nearly 200 other UCLA patients may have been exposed.
ABC News reports that all these outbreaks have occurred since FujiFilm, Olympus, and Pentax enclosed the elevator wire channels at the tips of the devices, which was supposed to make them easier to clean.
Olympus, which made the two duodenoscopes responsible for the UCLA infections, says in a product brochure announcing the change that “The elevator wire channel port is now sealed so separate cleaning is no longer necessary. The result is faster, easier cleaning that makes scope reprocessing more efficient.”
Olympus was the last of the manufacturers to make the change. Documents filed with the U.S. Food and Drug Administration (FDA) show that the company got federal approval for the design change last fall. Fujifilm was the first to enclose the elevator wire channels on its duodenoscopes in 2004, and Pentax followed in 2009.
Following the manufacturers’ instructions for cleaning the devices isn’t always enough to rid them of all bacteria. After 39 patients became infected with superbugs during duodenoscope procedures at an Illinois hospital in 2013, researchers with the U.S. Centers for Disease Control and Prevention (CDC) found the devices had been properly cleaned. However, they found antibiotic resistant strains of E. coli and other bacteria two months after some of the scopes were last used.
“The complicated design of duodenoscopes makes cleaning difficult,” the CDC researchers wrote. “It appears that these devices have the potential to remain contaminated with pathogenic bacteria even after recommended reprocessing is performed.”