Beyond Candida: Epidemiological Insights into Rare Yeast Fungaemia in Greece from a 15-Year Hospital-Based Study and Literature Review

Invasive infections attributed to rare yeasts are increasingly recognized and often exhibit resistance to echinocandins or fluconazole. Despite geographical variability, epidemiological data from Greece are limited. To bridge this gap, we conducted a 15-year retrospective study of rare yeast fungaemia at a tertiary teaching hospital in Athens. All microbiologically confirmed cases in hospitalized patients (2010-2024) were included. Demographic and clinical data were retrieved from medical records. Incidence was calculated per 1000 admissions and 10,000 bed days. Isolates were identified using Vitek 2 and, when available, further characterized by MALDI-TOF MS and tested for antifungal susceptibility based on EUCAST guidelines. A total of 29 episodes (3% of all fungaemias) were identified, with an incidence of 0.04/1000 admissions and 0.09/10,000 bed days. Hematological malignancies (31%) were the most common underlying condition. All patients had central venous catheters and were receiving antibiotics; 38% were non-neutropenic/non-immunosuppressed. The most frequently isolated species were <i>Rhodotorula mucilaginosa</i> (41%), <i>Saccharomyces cerevisiae</i> (31%) and <i>Trichosporon asahii</i> (21%), with single cases of <i>Apiotrichum loubieri</i> and <i>Magnusiomyces capitatus.</i> Amphotericin B exhibited good in vitro activity against all species; echinocandins were active only against <i>S. cerevisiae</i>, and azole activity was species dependent. The median time from hospital admission to fungaemia onset was 27 days; one-third of cases were breakthrough infections, and in 19%, diagnosis was established post-mortem. Despite antifungal therapy, crude mortality was 53%. Although infrequent, rare yeast fungaemia at our centre was associated with high breakthrough rates and substantial mortality. Regional epidemiological insight and heightened clinical awareness are key to optimizing outcomes.