Pseudomonas aeruginosa and Enterobacteriaceae bacteremia after biliary endoscopy: an outbreak investigation using DNA macrorestriction analysis

• Published in: The American journal of medicine Vol. 95; no. 5; p. 489
• Main Authors: Struelens, M J, Rost, F, Deplano, A, Maas, A, Schwam, V, Serruys, E, Cremer, M
• Format: Journal Article
• Language: English
• Published: United States 01-11-1993
• Subjects: Bacteremia - epidemiology; Bacteremia - etiology; Bacteremia - microbiology; Bacteremia - prevention & control; Bacterial Typing Techniques; Cholangiopancreatography, Endoscopic Retrograde - adverse effects; Disease Outbreaks; Disinfection - methods; DNA Restriction Enzymes; DNA, Bacterial - genetics; Electrophoresis, Gel, Pulsed-Field; Enterobacteriaceae Infections - epidemiology; Enterobacteriaceae Infections - prevention & control; Enterobacteriaceae Infections - transmission; Humans; Pseudomonas Infections - epidemiology; Pseudomonas Infections - prevention & control; Pseudomonas Infections - transmission; Seroepidemiologic Studies
• ISSN: 0002-9343
• DOI: 10.1016/0002-9343(93)90331-I

An outbreak of gram-negative bacteremia in patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) was investigated to determine the sources of infection and to control transmission.
The incidence of post-ERCP bacteremia increased from 1.6% (60 of 3,696) procedures to 3.6% (53 of 1,454) procedures (relative risk 2.3, p < 0.0001) after endoscopes were processed in a new automated disinfector. Bacteremia involved nine species of Pseudomonas and Enterobacteriaceae, which were also isolated from processed endoscopes. Seven epidemic strains with highly related genomic macrorestriction profiles each infected 2 or more patients, accounting for 29 (55%) episodes of post-ERCP bacteremia. Strains recovered from endoscopes and from the disinfector were associated with 22 (42%) and 5 (9%) bacteremic episodes respectively. Effective endoscope disinfection was achieved by cleansing and disinfection of a blind channel not processed in the disinfector, additional isopropanol-air flush of all channels, and auto-disinfection of the disinfector. In the following period, the incidence of post-ERCP bacteremia returned to the pre-epidemic rate (1.7%, p = 0.0001).
Bacterial genome fingerprinting by macrorestriction analysis enabled delineation of a multi-strain outbreak of post-ERCP bacteremia. Cross-contamination, and to a lesser extent, common-source contamination, appeared related to inadequate disinfection of endoscopes processed in an automated disinfector.