Interventions To Control an Epidemic of Bloodstream Infections due to Mycobacterium

BACKGROUND: Rapid growing Mycobacterium species are commonly found in water environments but are rarely associated with bloodstream infections (BSIs). During February–June 2002, an outbreak of BSIs due to M. chelonae and M. fortuitum was documented. The objective of this study was to describe the outbreak investigation and the interventions implemented to control the epidemic. METHODS: Isolation of M. chelonae or M. fortuitum from one or more blood cultures in a patient with a central venous catheter (CVC) was the case definition. Five patients met the case definition. All patients had underlying malignancies. None of the patients have evidence of local CVC site infection. Prior to development of infection, all patients had the CVC accessed for flushing. No common medications or caregivers were identified. Pulsed-field gel electrophoresis identified as identical three of four M. fortuitum strains. All environmental cultures were repeatedly negative. We hypothesized that the epidemic was likely related to the CVC flushing procedure and the following interventions were implemented: 1) do not open packages containing profiled saline syringes until immediately prior to use, 2) do not remove the cap and put the needleless device on the syringe until immediately prior to use. The success of control measures was determined by monitoring for recurrence. RESULTS: No additional cases of M. chelonae or M. fortuitum were identified in blood cultures after implementation of control measures. This study indicates that an epidemic of M. chelonae or M. fortuitum may result from intermittent, extrinsic contamination of sterile, preservative-free intravenous flush solutions.