Invasive fungal infections caused by rare yeast-like fungi in adult patients: results of a prospective study.

Background and Purpose: Fungal infections caused by rare pathogens are becoming an increasingly pressing problem in modern healthcare due to the severe course of the disease, high incidence of disability and mortality of patients. To study clinical and laboratory features and treatment of severe fungal infections caused by rare yeast-like pathogens in adult patients. Materials and Methods: The prospective observational non-interventional study (2004-2022) included 310 adult patients with severe fungal infections in the Kashkin Research Institute of Medical Mycology based on North-Western State Medical University named after I.I. Mechnikov, Saint-Petrsburg, Russian Federation (from October 2004 to December 2022). To identify the pathogen, we used direct microscopy, microscopy with calcofluor white, culture isolation from blood and tissue biopsies, cerebrospinal fluid or BAL fluid. Micromycete cultures were identified to species based on morphological characteristics and PCR-test. Results: We treated 310 adult patients with severe fungal infections -10% of them caused by rare yeast-like pathogens (n=30). Analysis of the data presented a general portrait of the patient: a 30-year-old man who has been in the ICU for more than 14 days (93%). Most often, the pathogen was isolated from the blood or biofilm of the central venous catheter (77%). Isolated damage to organs and tissues (without fungemia) was diagnosed in 23% of patients (involving the central nervous system, lungs and skin). Conclusion: It is necessary to examine the biological substrate from the lesion daily for fungi if there is no effect from standard therapy. It is necessary to perform species identification of the pathogen and determine sensitivity to antimycotics.