Knowledge of the local epidemiology of yeasts is important in guiding empirical treatment and monitoring trends over time. We examined all yeast susceptibility results performed at Royal Perth Hospital 1999-2014, a hospital managing a caseload including intensive care, burns, solid organ transplant, bone marrow transplant and difficult genital infections. Overall Candida albicans: fluconazole 13.6% intermediate (I) or resistant (R), voriconazole 11.6% I/R, caspofungin 0.9% I/R. Candida glabrata: fluconazole 16.3% R, caspofungin 16.5% I/R. Candida krusei: voriconazole 10.9% I/R, caspofungin 40% I/R. Candida parapsilosis: fluconazole 10.8% I/R, voriconazole 4.4% I/R, caspofungin 0.9% I/R. Candida tropicalis: fluconazole 17.5% I/R, voriconazole 16.7% I/R, caspofungin 0% I/R.
For Candida albicans, fluconazole MICs were significantly higher 2007-2014 compared to 1999-2006 (geometric mean MIC 0.94 mg/L vs 0.46 mg/L, p=0.004), while for C. parapsilosis fluconazole MIC was lower 2007-2014 compared to 1999-2006 (geometric mean MIC 0.99 mg/L vs 1.57 mg/L, p=0.007). Azole I/R rates of approximately 15% likely reflect referral bias of patients pre-treated with azoles. Notwithstanding difficulties with the validity of caspofungin testing, I/R rates of 16.5% for C. glabrata and 40% for C. krusei are concerning as echinocandins are the leading choices for serious infection with these Candida species.