Distribution of invasive fungal infections: Molecular epidemiology, etiology, clinical conditions, diagnosis and risk factors: A 3-year experience with 490 patients under intensive care

Recently, the prevalence of invasive fungal infections (IFIs) is rising. The global mortality rate of IFIs is 10–49%. This study aimed to determine the prevalence, the causative agents, and the risk factors associated with the invasive fungal infections in a tertiary health center to provide valid decision-grounds for healthcare professionals to effectively prevent, control, and treat fungal infections. The current study was conducted on 1477 patients suspected to have systemic fungal infections from different units of the hospital. After screening using routine mycological examination, the patients were confirmed with complementary mycological and molecular methods. Patients were included based on the confirmed diagnosis of IFI and excluded based on lack of a microbiologically and histologically proven diagnosis of IFI. Of the 1477 patients recruited in this study, confirmed cases of fungal infection were 490 (169 proven; 321 cases probable). Among the fungi recovered, Candida species had the highest frequency 337 (68.8%) followed by Aspergillus species 108 (22.1%), Zygomycetes species 21 (4.3%), non-Candida yeast 9 (1.8%). Others were black fungi 5 (1%), mycetoma agents 5 (1%), Fusarium 4 (0.8%), and Trichoderma (0.2%). Hematologic malignancies and diabetes mellitus were the most common underlying diseases among IFI-confirmed patients. This study observed an increased frequency of invasive candidiasis with non-albicans Candida and other invasive saprophytic fungal infections. The increased rate of invasive candidiasis with non-albicans agents highlights a new perspective in the epidemiology and treatment of invasive fungal infections. •This 3-year-long study was conducted on 490 inpatients diagnosed with IFIs at two major hospitals in Tehran, Iran.•This study suggests an increasing frequency of infection with saprophytes and non-albicans Candida as causes of IFIs.•Candida glabrata is the predominant non-albicans Candida causing IFIs.•Aspergillus flavus is the most common saprophyte implicated with IFIs.•Hematological malignancies are the dominant underlying disease among patient with invasive fungal diseases.