Invasive trichosporonosis caused by Trichosporon asahii and other unusual Trichosporon species at a medical center in Taiwan

Abstract

Background: During the past 2 decades, invasive trichosporonosis has emerged as an opportunistic infectious disease in immunocompromised patients. However, no case series have been reported recently.

Methods: All patients with a culture that was positive for Trichosporon species from May 2000 through May 2008 at a medical center were evaluated. The identity of all Trichosporon species was confirmed by analysis of the intergenic spacer 1 region of the fungal ribosomal RNA gene. In vitro susceptibility testing was performed using the reference broth microdilution method.

Results: Forty-three patients were found to have a culture that was positive for Trichosporon species. T. asahii was the most frequently isolated species (32 isolates; 74%), followed by T. dermatis (5; 12%), T. montevideense (2; 5%), and T. asteroides (1; 2%), T. cutaneum (1; 2%), T. faecale (1; 2%), and T. ovoides (1; 2%). Nineteen patients had invasive infections; 16 (84%) were caused by T. asahii, and 1 (5%) each was caused by T. dermatis, T. montevideense, and T. asteroides. Of the 19 episodes of invasive trichosporonosis, 14 (74%) were fungemia, 3 (16%) were pulmonary infection, and 1 (5%) each was soft-tissue infection and meningitis. Most invasive infections were associated with prior antibiotic therapy (95%), use of a central catheter (90%), malignancy (58%), and intensive care unit admission (47%). Azoles had good in vitro activity, whereas amphotericin B and echinocandins were not active against Trichosporon isolates. The 30-day all-cause mortality rate was 42% and was higher among patients with a malignancy (55%) than among those without an underlying malignancy (25%).

Conclusions: Invasive trichosporonosis tended to develop in patients with an underlying malignancy and to be associated with higher mortality. T. asahii and other unusual Trichosporon species may cause invasive trichosporonosis.