Species Distribution and Antifungal Susceptibility Patterns of Invasive Candidiasis in a Belgian Tertiary Center: A 7-Year Retrospective Analysis

Candidiasis is a major fungal infection worldwide, with invasive forms linked to high morbidity and mortality. The emergence of azole resistance in <i>Candida parapsilosis</i> causing candidemia led us to examine the epidemiology and antifungal susceptibility of <i>Candida</i> species at the University Hospital of Liège between January 2017 and December 2023. A total of 916 isolates from blood or sterile body fluids, tissues, and abscesses were analyzed. Species identification was performed using MALDI-TOF MS and antifungal susceptibility testing via Sensititre YO10 AST was interpreted according to the CLSI guidelines. <i>Candida albicans</i> remained the predominant species (56%), followed by <i>Nakaseomyces glabratus</i> (19%), <i>Candida parapsilosis</i> (8%), and <i>Candida tropicalis</i> (7%). No significant shift toward non-<i>albicans Candida</i> species (NAC) was observed even during the COVID-19 pandemic, supporting the use of narrow-spectrum empirical therapy in selected patients. Fluconazole susceptibility was high in <i>C. albicans</i> (98.8%), whereas <i>N. glabratus</i> and <i>C. tropicalis</i> showed high resistance rates with 10.1% and 16.9%, respectively. <i>C. parapsilosis</i> showed stable fluconazole susceptibility across the study period. Echinocandins demonstrated excellent activity (95.6-100%), and amphotericin B was effective against nearly all isolates. This seven-year surveillance at the University Hospital of Liège confirms that while <i>C. albicans</i> remains the predominant and highly susceptible species, rising azole resistance in non-<i>albicans Candida</i>-particularly <i>N. glabratus</i> and <i>C. tropicalis</i>-highlights the critical need for ongoing local epidemiological monitoring to guide effective and targeted antifungal therapy.