Coronavirus Disease 2019–Associated Mucormycosis: Risk Factors and Mechanisms of Disease

Abstract The severe surge of coronavirus disease 2019 (COVID-19) cases on the Indian subcontinent in early 2021 was marked by an unusually high number of COVID-19–associated mucormycosis (CAM) cases reported during this same period. This is significantly higher than predicted based on available data about prevalence and risk factors for this condition. This may be due to an unusual alignment of multiple risk factors for this condition. There is high background prevalence of mucormycosis in India likely from a high prevalence of risk factors, including undiagnosed or poorly controlled diabetes. COVID-19–induced immune dysregulation and immune suppression from steroid therapy increase the risk. The role of environmental exposure is unclear. System factors such as lack of access to healthcare during a pandemic may result in delayed diagnosis or suboptimal management with potentially poor outcomes. Here, we review currently identified risk factors and pathogenesis of CAM in a pandemic surge. The spike in cases of coronavirus disease 2019–associated mucormycosis reported from India during the pandemic surge in early 2021 may be due to an unfortunate alignment of multiple risk factors, chiefly dysglycemia and steroid therapy superimposed on high background prevalence.