Pasadena health officials said Wednesday that 16 patients were infected by dangerous bacteria from medical scopes at Huntington Hospital from January 2013 to August 2015, including 11 who have now died.
Many of those patients were already severely ill, including some with cancer. Health officials said that only one of the 11 death certificates listed the bacteria as the cause. It was not clear if infection was a factor in any of the other deaths.
The hospital had previously said just three patients were infected in the outbreak that officials said was limited to the middle of 2015.
The patient infections were detailed in the Pasadena Public Health Department's investigation into the outbreak. The report blamed both the design of the scope and the hospital for lapses in infection control.
For example, investigators discovered visible residues in the machines used to clean the scopes, according to the report released on Wednesday.
Investigators also said the hospital had been using canned compressed air from Office Depot to dry the scopes – which is not recommended by the manufacturer or by cleaning guidelines.
Pasadena health officials said they had found no additional scope-related infections since the start of their investigation on Aug. 19.
Dr. Paula Verrette, Huntington's chief medical officer, said Wednesday the hospital has now changed its practices based on the findings and recommendations of health officials.
"Patient safety remains our highest priority," she said.
Lawrence Muscarella, a medical safety consultant in Montgomeryville, Pa. who has been following the scope outbreaks, said the Pasadena case showed that many more patients may have been infected across the country than has been publicly reported.
"This shows a total failure of the system, from top to bottom," said Muscarella.
Huntington hospital officials had confirmed last August that three patients were sickened the previous month but declined to say more about their condition. They later told Olympus Corp., the scope's manufacturer, of at least three deaths, according to the company's report to federal regulators.
When the regulatory reports were discovered, hospital officials said that they believed patient privacy laws prevented them from telling the public that the unnamed patients had died.
The investigation said that Huntington doctors had started doing their own review of possible infections in July after finding three patients sickened with drug-resistant Pseudomonas aeruginosa.
The hospital staff had identified as many as 35 cases of possible infections, which they had been evaluating before Pasadena officials arrived on Aug. 20 in an unannounced site investigation.
The health officials concluded that 15 of these cases were linked to procedures the patients had with an Olympus scope.
Then in March, hospital officials told the health department that they found an additional patient who was infected. That patient had a scope procedure in July 2013.
The hospital found 13 other patients infected with the bacteria but determined they were not sickened by the scopes.
Huntington doctors told health officials on May 23 that they were now notifying all patients who had been treated with the scopes since January 2013 about the possibility of infections.
Previously, the hospital had notified only those patients who had been treated between Jan. 2015 and August 20, 2015.
The duodenoscope is a long snake-like tube with a tiny camera on the tip that is inserted into a patient's throat and upper gastrointestinal tract. It is used to treat cancer, gallstones and other problems in the bile or pancreatic ducts.
In January, Olympus recalled one model of its reusable duodenoscopes because of the possibility that it could transfer bacteria between patients. That model was linked to two other Southern California outbreaks at UCLA Ronald Reagan Medical Center and Cedars Sinai Medical Center.
Two of the reusable scopes suspected of causing the Pasadena outbreak had a different, older design from the one that Olympus recalled.
The investigation said that tests had found the bacteria Pseudomonas aeruginosa on three of Huntington's scopes.
Investigators also found another kind of bacteria inside the washer used to clean the scopes.
"This broad bacterial contamination," the report said, "supports the hypothesis" that disinfection and maintenance "were insufficient to prevent the spread of infection."
In a visit on September 11, Pasadena officials found that the hospital had improved its cleaning of scopes, including doing "major maintenance" on the machines used to disinfect them.
They said that Olympus specialists had been to the hospital multiple times to train the staff on proper disinfection procedures.
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