Background: FCZ disk diffusion susceptibility testing (FDDST) using CLSI M44-A methodology was implemented in 6/2003. Prior to this, results of FCZ MIC testing for Candida spp. required up to 7 days. FDDST provides results within 24h of Candida spp. isolation on solid media. The test is inexpensive and easy to perform in a clinical laboratory. Increasing use of echinocandins (ECH) for Candida glabrata due to concerns of FCZ resistance provided impetus to initiate testing. We evaluated 3 years of data to determine whether the rapid availability of FDDST results avoided unnecessary antifungal expenditures. Methods: Data on Candida spp. blood cultures and C. glabrata urine cultures from 1/03 to 5/06 were retrieved. Charts were reviewed for all above isolates with FDDST results. Data collected included patient location, species, FDDST results, antifungal(s) used, duration of therapy, and outcome. Our antimicrobial management service (AMS) database was also reviewed for interventions on ECH, L-AmB, and voriconazole usage related to FDDST. Results: 174 patients had FDDST performed on their Candida spp. isolates. 114 patients had FDDST results reported on blood isolates; 40 patients had FDDST results reported on C. glabrata urine isolates. The AMS database identified 12 non-blood isolates where FDDST contributed to changes in patients’ therapy. 17 C. glabrata, 31% of C. glabrata isolates tested, were resistant to FCZ and all but 2 cases resulted in ECH use. One C. tropicalis urine isolate and 1 C. albicans from an oncology patient were resistant to FCZ. Cost avoidance = (agent 1-agent 2) X duration of therapy. All changes were from ECH to FCZ. 21 patients with blood isolates had their therapy changed with an estimated cost avoidance of $66,630. A total of 37 patients had their therapy altered based on FDDST results. Total cost avoidance was $116,107 in 3 years. Conclusion: FDDST has a positive long term impact on antifungal agent expenditures.
Full conference title:
Infectious Diseases Society of America, 44th Annual Meeting
- IDSA 44th