Epidemiology of mucormycosis in COVID-19 patients in northwest Iran: Rhizopus arrhizus as the predominant species

Background and Purpose: The current study aimed to assess the demographic features, clinical characteristics, species diversity, and contributing factors among patients with severe acute respiratory syndrome coronavirus-2 pneumonia-associated mucormycosis in northwestern Iran.Materials and Methods: This cross-sectional descriptive study was performed on patients who tested positive for COVID-19 via reverse-transcriptase-polymerase chain reaction and were suspected of having invasive fungal infection. Mucormycosis was confirmed by histopathology of biopsy samples and species identification was performed using morphological and internal transcribed spacer-rDNA sequencing methods.Results: Mucormycosis was observed in 63 COVID-19 patients. Mean age of patients was 56.65±14.49 years (range of 22-85 years) and 63.5% of the involved patients were male. The most common involvement site of patients with mucormycosis was the sinus (63.5%). Among all participants, 84% of patients (n=53) had received intravenous dexamethasone, and 25.4% of them had diabetes mellitus. All patients with proven invasive mucormycosis received intravenous amphotericin B. In total, 21 (33%) positive cultures were identified and Rhizopus arrhizus was the main causative agent.Conclusion: Awareness among physicians should be raised that corticosteroid therapy not only causes dysfunction of the immune system but may also lead to the development of this neglected mycosis through corticosteroid-induced diabetes in vulnerable patients.