A pseudo-outbreak of Methylobacter related to bronchoscopy

ISSUE: At a 600-bed county teaching hospital from October 2001 to March 2003, Legionella media inoculated with bronchoaveolar lavage (BAL) specimens sporadically grew Methylobacterium species. Methylobacterium is a fastidious gram-negative rod that can cause opportunistic infections. Factors that could lead to contamination during pulmonary procedures include breaks in aseptic technique in caring for scopes, absence of proper training in reprocessing, and absence of an area dedicated solely for bronchoscopy. An investigation was initiated to determine the source of this pseudo-outbreak, implement interventions, eliminate the transmission of all organisms, and prevent true infections. PROJECT: Surveillance began with the first suspected episodes. A case was defined as a patient with Methylobacter positive BALs. Episodic environmental cultures were obtained. Bronchoscope procedures were reviewed and infection control measures reinforced. Infection control implemented mandated education and competency training for all hospital personnel handling or reprocessing scopes. The laboratory performed 100 consecutive Methylobacter cultures on respiratory specimens using Legionella media for optimum growth. RESULTS: Chart review and data collection identified 10 cases in the outbreak period. The appearance of Methylobacterium occurred only with bronchoscopes (n = 249) cared for in the bronchoscopy suite. The attack rate was 4.0%. There was no correlation with bronchoscopes (n = 660) used in the operating room (p = 0.000002). No clinical Methylobacter infections were detected. Breaches were identified in infection control practices based on manufacturerʹs guidelines, including the need for bronchoscope sterilization immediately before each use (“just-in-time”), 70% isopropyl alcohol rinse, filtered forced air-drying after scope processing, vertical storage of scopes with removable parts detached, and clearly marked delineation of room “clean” and “dirty” areas. Methylobacter was isolated from a sink drainpipe and faucet extension in the bronchoscopy suite. Both were replaced. The pseudo-outbreak ceased following implementation of guidelines. LESSONS LEARNED: Key elements for patient safety are scope-reprocessing guidelines, standardizing competencies throughout the hospital, and providing competency education, training, and documentation. Centralizing the reprocessing of all scopes is our future goal.