Mucormycosis, New Causative Agents, and New Susceptible Populations: Review of Cases in a Tertiary Care Hospital in Iran (2007-2021).

Background: Mucormycosis is an aggressive opportunistic fungal infection that afflicts patients with severe underlying immunosuppression, uncontrolled hyperglycemia and/or ketoacidosis, iron overload, and occasionally healthy patients who are inoculated with fungal spores through traumatic injuries. The epidemiology of mucormycosis has changed after the COVID-19 pandemic, with mucormycosis becoming the most common and the fatal coinfection. Methods: In a retrospective, cross-sectional study, 82 hospitalized patients with a definite diagnosis of mucormycosis were reported from 2007 to 2021 in a referral, tertiary care center in Tehran, Iran. Results: The number of post-COVID cases increased 4.6 times per year, with 41.5% of patients admitted during the two years of the pandemic. Mucormycosis was more common in women (57.3%), and the most common underlying diseases were diabetes (43.7%), both COVID-19 and diabetes (23.2%), cancer (11%), rheumatic diseases (7.3%), COVID-19 without other underlying diseases (6.1%), and transplantation (4.9%). Rhino-orbito-cerebral Mucormycosis (54.9%) followed by Sino-orbital infection (23.2%) was the most common presentation. There was a significant relationship between the use of immunosuppressive agents and the development of Mucormycosis (P<0.005) The average mortality was 41.5%, but this ratio decreased to 35% during the pandemic era. Conclusion: The COVID-19 pandemic caused a 4.6-fold increase in the number of mucormycosis patients, and there was a significant relationship between hyperglycemia, corticosteroid use, and mucormycosis. The death rate during the COVID-19 pandemic has decreased by 6.5%, and during the COVID period, the interval between the arrival of a patient with mucormycosis and the start of the correct treatment was significantly decreased.