Contaminated duodenoscopes manufactured by the Olympus Corporation were said to be the source of the "superbug," according to an investigation launched by the Pasadena's Huntington Memorial Hospital. The patients were found to have contracted multidrug-resistant pseudomonas bacteria after coming into contact with the medical instruments.
The reusable scopes are essentially fiber-optic devices inserted into a patient's throat. The procedure is known as endoscopic retrograde cholangiopancreatography, and is used to treat gallstones, blockages, and cancers of the digestive tract.
"The patients who experienced the bacterial growth were very ill before they underwent the scope procedure, and the risk of the procedure was explained to each patient and family," reads a statement released by the hospital.
Although the hospital made assurances that the scopes have been placed in quarantine, it has not revealed the precise number of infected patients or their conditions. But according to the Los Angeles Times, a superbug outbreak in June led to three cases of infections.
Cedars-Sinai and UCLA's Ronald Reagan medical centers, both based in Los Angeles, also reported a dozen infections earlier this year. Three died.
The hospitals defended their actions by claiming the equipment had been cleaned to the standards recommended by the manufacturer. More stringent disinfection procedures have since been put in place.
Last week, the FDA issued a warning that Olympus had failed to report that its duodenovideoscopes "may have caused or contributed to a death or serious injury." That instance related to 16 patients who became infected after undergoing procedures with the device three years ago.
FDA regulations state that medical device companies are required to report any kind of instrument problems in "no later than 30 calendar days."
Olympus said it was currently reviewing the FDA's warning, according to the Associated Press.