Researchers Report on Cluster of Pseudoinfections Associated With Contaminated Washer-Disinfector

July 27, 2010

Dror Rosengarten, MD, of the Institute of Pulmonology at Hadassah-Hebrew University Medical Center in Jerusalem, and colleagues, reported on a cluster of pseudo-infections in patients in a bronchoscopy unit who had Burkholderia cepacia isolated from bronchoalveolar lavage fluid samples.

The researchers report that in December 2008, bronchoalveolar lavage fluid samples obtained from three patients were positive for Burkholderia cepacia complex on culture. Samples obtained from bronchoscopes and rinse-water samples obtained from the washer-disinfector were found to be positive for B. cepacia complex. The researchers report that samples obtained from the reverse osmosis water at the inlet to the washer-disinfector yielded no growth on culture; however, those cultures obtained from the basin surface gew B. cepacia complex on culture. The researchers add that the reprocessing procedure was observed but no substantial breach in technique was found. Upon examination, it was found that the antibacterial filter on the water supply line was missing and that this was the probable cause of the cluster.

The researchers note, "Multiple avenues for contamination ... have been described, including ineffective bronchoscope cleaning, problems with disinfectants, and contaminated reprocessing equipment. Although the use of automated endoscope reprocessors has helped healthcare workers to maintain standards of disinfection, these reprocessors may also be the source of bronchoscope contamination. Although the insides of these devices are periodically disinfected, their water supply tanks, tubing and pumps are not always in contact with disinfectants, and these areas may serve as reservoirs for contaminating pathogens. Biofilm on the surfaces of the basin may protect organisms during disinfection cycles." They add further that despite detailed recommendations for preventing contamination during bronchoscope reprocessing, "it appears that this problem is underrecognized and underreported."

Reference: Rosengarten D, et al. Cluster of Pseudoinfections with Burkholderia cepacia Associated with a Contaminated WasherDisinfector in a Bronchoscopy Unit. Infect Control Hosp Epidemiol 2010;31:769-771.