Antifungal use influences Candida species distribution and susceptibility in the intensive care unit

Objectives: Antifungal prescription practices have changed over the last decade, and the impact of these changes is unclear. Our objective here was to evaluate the effect of antifungal drug use on the distribution and drug susceptibility of Candida spp. in a French intensive care unit (ICU). Methods: Antifungal drug use was measured as the number of defined daily doses per 1000 hospital days (DDDs/1000HD). The distribution of Candida spp. over a 6 year period (2004-09) and the MICs of antifungal drugs over 2007-09 were determined. Statistical analyses were performed to assess relationships between antifungal drug use, Candida spp. distribution and MIC changes over time. Results: Of 26450 samples from 3391 patients, 1511 were positive for Candida spp. Candida albicans predominated (52.5%), followed by Candida glabrata (16.6%) and Candida parapsilosis (7.5%). C. parapsilosis increased significantly, from 5.7% in 2004 to 12.5% in 2009 (P=0.0005). Caspofungin use increased significantly between 2004 (17.9 DDDs/1000HD) and 2009 (69.9 DDDs/1000HD) (P<0.0001). Between 2007 and 2009, the increase in caspofungin use correlated significantly with the increase in caspofungin MICs displayed by C. parapsilosis (P<0.0001) and C. glabrata (P=0.03). Amphotericin B consumption changed over time and correlated with an increase in amphotericin B MICs for C. albicans (P=0.0002) and C. glabrata (P=0.0005). Significant declines occurred in both fluconazole use (P<0.0001) and fluconazole MICs of C. albicans (P<0.001) Conclusions: Antifungal drug use in the ICU is associated with major changes in the distribution and drug susceptibility of Candida spp.