Background and purpose: Infections due to rapidly growing mycobacteria (RGM) are increasing worldwide, especially in immunocompromised hosts, but data on the clinical features of patients with RGM bacteremia are limited in Taiwan. This study was performed to determine the features associated with RGM.
Methods: The medical records of 12 patients with RGM bacteremia admitted to the Changhua Christian Hospital, Changhua, Taiwan, from April 2001 to March 2003 were retrospectively studied. Clinical data were reviewed and antimicrobial susceptibility testing of blood isolates by the agar disk elution method was performed.
Results: RGM bacteremia was caused by Mycobacterium fortuitum in 5 patients, Mycobacterium smegmatis in 3, Mycobacterium flavescens in 2, and Mycobacterium abscessus in 2. There were 5 men and 7 women (age range, 4-75 years). All patients had underlying diseases and all of the infections were associated with an indwelling vascular catheter. The time to onset of bacteremia ranged from 1 to 24 months. Fever (n = 11) was the most common presenting symptom. Susceptibility testing revealed a different antibiogram for each species of RGM. The rate of relapsing bacteremia was significantly higher in patients with delayed catheter removal and for whom the catheter was not removed (6/8; 75%) than in patients with timely catheter removal (0/4; 0%) [p = 0.03].
Conclusions: RGM bacteremia is rare but should be considered in immunocompromised patients with an indwelling venous catheter and undifferentiated fever. Identifying RGM at the species level and performing susceptibility testing are useful for guiding management. The catheter should be removed as soon as possible.