Outbreaks of contaminated broncho-alveolar lavage related to intrinsically defective bronchoscopes

From 5 March 2001 to 19 October 2001, outbreaks of broncho-alveolar lavage (BAL) contamination with Enterobacteraceae were detected in our 700-bed institution. We report the investigation of these outbreaks. A case was defined as the occurrence of pairs of specific Enterobacteraceae in BAL specimens among any patients who underwent bronchoscopy in the respiratory unit during the period of the outbreak. Contamination was identified in 117 BAL samples during three outbreaks among 418 patients, and was associated with bronchoscopes 11 and 12 (P<0.001). The other five devices in use were not linked with the outbreaks. During the first outbreak, particular pairs of micro-organisms were associated with a specific bronchoscope (Klebsiella pneumoniae/Proteus vulgaris with bronchoscope 11, and Morganella morganii/Proteus mirabilis with bronchoscope 12). Cultures of sputa from two patients also yielded M. morganii some days after bronchoscopic examination. Isolates from contaminated BAL samples and bronchoscope 11 had similar patterns by pulsed-field gel electrophoresis. No further cases occurred after removal of the implicated bronchoscopes. No deficiencies in disinfection procedures were detected and the source of contamination was found to be a loose port of the biopsy channel of the bronchoscope. Our findings underscore the urgent need to test bronchoscopic samples regularly and to improve the design and structure of bronchoscopes.