Experts say bronchoscopes, which doctors use to examine lungs and take tissue samples from airways, pose a small but real risk of transferring germs from one patient to another, despite the sterilizing steps used to clean them.
The scopes are the focus of an investigation at Johns Hopkins University in Baltimore, which is trying to determine whether the devices were responsible for infecting at least 100 patients with the Pseudomonas aeruginosa bacteria. Two patients have died so far, said Gary Stephenson, a Hopkins spokesman, and "there may be other deaths that we don't know about presently."
Health officials have issued at least two reports since the early 1990s notifying doctors of the problem. The alerts, from the Centers for Disease Control and Prevention, each stated that automated sterilizing gear failed to completely destroy bacteria clinging to the instruments. The cleaning machines themselves also housed colonies of dangerous germs.
Dr. Norman Edelman, a scientific consultant for the American Lung Association, said inadequate cleaning of bronchoscopes "has been an issue" in the past. "Good programs check whether the sterilization is effective," he added.
"Getting pneumonia or infection from bronchoscopy is always a complication," said Dr. Marc Judson, a pulmonologist at the Medical University of South Carolina in Charleston. "It's more likely to occur with a bronchoscope that was recalled."
The risk reflects the fact that bronchoscopy isn't a sterile procedure, Judson added. When doctors thread the snakelike tube through a patient's mouth or nose, it may transfer harmful germs loitering there deeper into the body. "The scope itself is not sterile, and even if it was sterile, you're going to bring bacteria down into the lung," Judson said.
And when the devices have flaws that shield these bacteria from cleaning machines, or when the cleaning machines don't work properly, infections can spread from patient to patient.
In the latest incident, Olympus America issued a recall notice last November to hospitals that use its bronchoscopes alerting them to a loose biopsy port that might have hidden bacteria.
Doctors at Hopkins detected a surge in Pseudomonas aeruginosa infections in late December, officials there said. They found traces of the bacteria in three of their seven Olympus bronchoscopes.
Hopkins officials said they didn't learn of the recall until February. On March 4, the university sent letters to 415 patients who had undergone bronchoscopy at Hopkins, warning them of the potential infection risk.
Of those patients, 100 have tested positive for Pseudomonas bacteria, two to three times as many as would normally be expected, according to a university statement.
Many of the patients have serious illnesses such as AIDS, cancer, and cystic fibrosis, the statement said. Because of that, "it is likely that some of these patients carried the Pseudomonas bacteria before they came to Hopkins for their bronchoscopies," the statement said. Whether the defective bronchoscopes were to blame is "what we're trying to ascertain now," said Stephenson, the Hopkins spokesman.
An official at the Centers for Disease Control and Prevention said this week that Olympus learned about the problem with their bronchoscopes in September but waited until November to notify hospitals. The official, Dr. William Jarvis, said Olympus, a unit of the Japanese optics maker, didn't inform the Food and Drug Administration of the defect until December, according to the Associated Press.
Olympus defended its handling of the recall, saying in a statement that it notified its customers in a "timely" manner about the troubled devices.
Sandra McDonald, a spokeswoman for Olympus, said the company issued two recall notices, one on Nov. 30 and a follow-up letter on Feb. 27, regarding the flaw. Both were marked "Urgent: Recall" in large, bold lettering.
In all, Olympus sent 2,361 notices to hospitals and institutions that own the instruments, McDonald said. "All of those institutions have been notified through the certified mail recall process following FDA guidelines," she added.
Sharon Snider, an FDA spokeswoman, said Olympus has been "cooperative and responsive" to the agency's requests for information about the defective bronchoscopes.
"We want to make sure that the hospitals were properly notified and make sure that these devices are out of circulation," said Snider, who added that the root cause of the infections at Hopkins has not been confirmed.
In a 1991 report, the CDC detailed infections linked to bronchoscopes and endoscopes -- similar devices which enter the body from the rectum or urethra --in Wisconsin and Missouri. Those infections, which included Pseudomonas aeruginosa and another dangerous germ, Mycobacterium chelonae, were traced to the automated cleaning devices used to sterilize deployed scopes.
In July 1999, the CDC released a report on three clusters of bronchoscope-related infections in New York. The cases, which occurred in 1996 and 1998 and included tuberculosis, were again related to problems with automated machines used to clean the devices.
The CDC said that in 1996, doctors performed almost 500,000 bronchoscope procedures.