Hospital officials review sterilization methods
Allegheny General Hospital's investigation of an outbreak of deadly bacteria is focusing on whether its accepted sterilization techniques failed to disinfect diagnostic scopes used to inspect the lungs, officials said Tuesday.
The hospital has linked the infected scopes to one death and said 11 other patients have been exposed to the bacteria, an antibiotic-resistant strain of Pseudomonas aeruginosa.
Since making the announcement, about 145 worried patients flooded the hospital with calls. About half of them plan to go back to Allegheny General for further testing, said Dr. Richard Shannon, chairman of the hospital's department of medicine,
"Most of them will not require treatment," Shannon said. "Those decisions are going to be made on an individual basis, depending on what other illnesses the patients might have."
Allegheny General announced Monday it is trying to determine how three of 19 bronchoscopes, commonly used to test lungs in critically ill patients, became infected. Meanwhile, officials of the Centers for Disease Control and Prevention, which is helping in the investigation, said they are not aware of current outbreaks at other hospitals besides Allegheny General.
"We do not have an indication that this is a national problem," said Dr. Dan Jernigan, a medical epidemiologist who studies disease outbreaks at the CDC.
Jernigan said the federal agency has no plans to issue an alert regarding the sterilizing techniques used to clean the bronchoscopes at Allegheny General. He said the techniques are common practice and no problems have been documented in the past.
Because pseudomonas can live in humans without causing sickness, it is possible that some Allegheny General patients may have carried the bacteria prior to their treatment at the hospital.
Doctors have urged 450 patients who underwent bronchoscopies at the North Side hospital to call a toll-free hot line. Shannon said the hot line is working well to allay fears and misconceptions about the bacteria, which mostly can be troublesome in people with weak immune systems.
Shannon said hospital officials may not know for a week exactly what triggered the outbreak, which contributed to the death of one patient early this month. Shannon said the hospital is focusing on the cleaning procedure. None of the infected instruments had been subject to a recall by their manufacturers.
Similar instruments used at Johns Hopkins Hospital in Baltimore had been recalled in March because they had loose valves that trapped bacteria.
"There had been no recalls and that means we're focusing on the sterilization process," Shannon said yesterday.
The last time the CDC reported improperly cleaned bronchoscopes was in 1999. The CDC reported in July of that year three clusters of bronchoscope-related infections in New York over a two-year period. An investigation found conflicting instructions on how to properly clean the scopes, inadequate training of workers and problems with automated cleaning machines.
Shannon said Allegheny General's investigation has so far revealed no human error.
"We have checked all the laboratory personnel and have made sure that they have been following all the procedures documented in our quality assurance manuals, and so far it looks like they have," he said.
As a precaution, workers are discontinued a common cleaning technique that includes using an enzymatic detergent and putting the scopes in a sterilization machine. Instead, the hospital is cleaning the scopes with a longer, gas sterilization technique.
Gas sterilization is being used at UPMC Presbyterian in Oakland. Infection control specialists there said they reviewed their cleaning techniques earlier this year after the Hopkins incident.
Dr. Carlene Muto, director of infection control at Presby, said some bronchoscopes used at UPMC were made by Olympus America, the same company that made the faulty bronchoscopes recalled in Baltimore. Presby sent them back to Olympus for inspection and they were not found to be defective, Muto said.
"After the Hopkins incident, we've put a lot of attention on bronchoscopes," she said. "We've spent a lot of energy making sure that all the cleaning and sterilization processes we have in place are acceptable."
Doctors yesterday said patients who have undergone examinations of other organs using scopes should not fear infection. The chances of a scope spreading bacteria are extremely low. Even they would transmit bacteria, other parts of the body are not as susceptible to infection as the lungs.
"It's nowhere near as big of an issue to put something infected in your (gastrointestinal) tract as opposed to putting it into your lungs," Muto said. "Your gut is full of normal bacteria that is supposed to be there."