Prevalence of invasive yeast infections in a COVID-19 intensive care unit in northeastern Brazil

The COVID-19 pandemic has caused a global crisis, overwhelming hospitals and intensive care units (ICU) and leading to an increase in nosocomial infections due to prolonged hospitalization and other risk factors. The present study evaluated the prevalence of secondary fungal infections in critically ill patients with COVID-19. This is a retrospective, single-center study conducted in a hospital in northeastern Brazil, which evaluated 1,364 medical records of patients admitted to a COVID-19 ICU during 2020 and 2021. A total of 327 pathogenic yeasts were isolated from 132 (40.4%) respiratory, 70 (21.4%) blood, 124 (37.9%) urine, and one (0.3%) surgical wound samples. Fungal infections were diagnosed in the intermediate (5 to 12 days) or late (≥12 days) stage of hospitalization. The most frequent yeast isolated from critically ill COVID-19 patients was Candida albicans [126 (67.7%) and 60 (42.6%)], followed by Candida tropicalis [25 (13.4%) and 39 (27.7%)]. Candida parapsilosis isolates increased 5.7-fold in 2021 [40 (28.4%)] compared to 2020 [7 (3.8%)]. The least frequently isolated in 2020 and 2021 were Nakaseomyces glabratus [4 (2.2%) and 1 (0.7%)], and Pichia kudriavzevii, which was isolated only in 2021 (1 (0.7%)). During the study period, a decrease in susceptibility to antifungals was observed: susceptibility to voriconazole reduced from 100 to 77.2%, to flucytosine from 99.4 to 78.8%, and to micafungin from 99.4 to 83.6%. The changes in the frequency of species causing secondary infections in critically ill COVID-19 patients and susceptibility to the antifungals indicate the need for early and adequate diagnosis to minimize negative outcomes.