Vanderbilt’s Dr. William Schaffner.
Investigative team exposes equipment dangers: NEJM
A unique collaboration among Vanderbilt University Medical Center, the Tennessee Department of Health, the Centers for Disease Control and Prevention and Skyline Medical Center recently sparked an international recall of a defective medical instrument, halting the spread of infectious bacteria to patients and possibly saving hundreds of lives worldwide.
The collaboration resulted in a study published last week in the New England Journal of Medicine explaining the incidents of Pseudomonas aeruginosa and Serratia marcescens and a link to defective bronchoscopes.
The inquiry began in 2001 after Glenda Mayernick, an infection-control practitioner, and Dr. Jayesh Patel of Skyline notified the TDH of an increase in the number of P. aeruginosa and S. marcescens isolates associated with bronchoscopy. About 500,000 bronchoscopic procedures are performed each year in the United States.
Dr. David Kirschke, a member of the CDC’s Epidemic Intelligence Service (EIS) on assignment in Nashville, was notified of the incidents and he contacted Vanderbilt’s Dr. William Schaffner, an alumnus of the EIS and professor and chair of Preventive Medicine at Vanderbilt. Drs. Allen Craig and Tim Jones, epidemiologists from the TDH, and Dr. Patricia Chu, an emergency medicine resident at Vanderbilt who was doing a rotation at the TDH, rounded out the team of investigators called in to determine the source of the bacteria.
Reviewing endoscopy records, the team pinpointed the bronchoscopes used in the procedures by serial numbers and began the testing process in Tennessee.
From July to October 2001, 66 bronchoscopic procedures were performed on 60 patients, and 43 specimens were obtained for bacterial culture. Of the 43, 20 of the specimens, or 47 percent, were positive for P. aeruginosa. Six (30 percent) of the specimens that were positive for P. aeruginosa also yielded S. marcescens.
The bacteria were linked to defective bronchoscopes manufactured by Olympus America, a division of Olympus Optical Company in Tokyo. The caps of the biopsy ports were not securely fastened and were easily removable, contrary to manufacturer specifications. Swabs of the threads of the ports and inside the caps tested positive for the bacteria. The problem of loose caps was limited to certain new bronchoscope models; older bronchoscope models were not affected.
Air pockets in the biopsy-port caps that prevented effective contact between disinfectants and the microorganisms when submerged during cleaning were pinpointed as the culprits of the spreading bacteria. Also, the design of the caps prevented thorough cleaning and drying of surfaces inside the caps, thus providing an environment where the bacteria could survive the usual disinfection procedures, according to the doctors.
“This was an example of exactly how the system is designed to work,” Schaffner said of the notification process by the practitioners at Skyline and the collaboration of the other institutions. “When public health is done right with partners, there’s power there.”
After determining the health risk, the team notified the FDA of the manufacturer defect. However, the recall process was not handled as efficiently as the investigative procedure, according to Schaffner.
Olympus issued a recall of certain models in November 2001 after receiving the report from Tennessee-based team. The voluntary recall affected 15 models of bronchoscopes, involving 4,700 devices in the United States, and was further expanded to include 14,000 bronchoscopes worldwide. However, there were problems with the recall.
Doctors at Johns Hopkins Hospital did not receive the November 2001 recall letter until January 2002, and the letter was addressed to a loading dock of another department across the street from the hospital. While the recall letter floated through the system, Hopkins officials had already noticed an increase in pseudomonas infection and launched their own investigation. Two patients at Hopkins who were critically ill at the time the device was used on them died of pneumonia.
The medical team in Nashville thinks both the company and the FDA should have been more aggressive in carrying out the recall in order to be sure that all providers who used these defective bronchoscopes had been contacted.
“The FDA should have recognized that what we reported to them had direct implications to public health,” Schaffner said. “It posed an immediate hazard. The recall letter never stated that it was a danger to health. The FDA’s role was quite passive.
“This could be the occasion to examine the process of FDA oversight of manufacturers and how recalls actually are carried out. Perhaps the FDA needs enhanced enabling legislative authority and increased resources to improve performance.
“These are the sorts of issues likely to come up as we develop more and more complex devices.”