Risk Factors Associated with the Mucormycosis Epidemic During the COVID-19 Pandemic

PURPOSE: The second wave of the COVID-19 pandemic in India is associated with an unprecedented surge of patients with mucormycosis. This study assessed the risk factors driving the epidemic of COVID-19 associated mucormycosis (CAM) and addressing these risk factors could reduce morbidity and mortality among vulnerable populations. METHODS & MATERIALS: This is a case-control analysis of risk factors in 164 adults from a prospective cohort database, the POISE Mucor Study, approved by the institutional review board and ethics committee with proven invasive mucormycosis of paranasal sinuses admitted in a tertiary care hospital in South India from 01.07.2020 to 10.06.2021 included after informed consent. Cases were patients with COVID-19 confirmed by RT-PCR for SARS-CoV-2 on a nasopharyngeal sample within three months of mucormycosis. Patients with ROCM (Rhino-orbito-cerebral mucormycosis) negative RT-PCR for SARS-CoV-2 were the controls. RESULTS: The mean age of the 164 patients (132 cases and 32 controls) was 51 years, and 78% were men (table 1). Most patients with CAM had mild COVID-19 (76.7%); 16.3% and 7% had moderate and severe/critical disease, respectively. Almost all patients presented with acute ROCM within 3 months of COVID-19 occurrence. Diabetes mellitus (present in 97%) remained a strong predisposing factor in both groups. Uncontrolled diabetes mellitus (HbA1c of >7.0%), 40% of which was newly detected, was associated with CAM (OR: 4.6; p=0.026). Diabetic ketoacidosis and mean HbA1c values were not. Steroid use was common, even in mild disease, and was strongly associated with CAM (OR:38.3; p<0.001). Oxygen use was uncommon among cases (14.4%). Serum ferritin was significantly higher among patients with CAM (p=0.041); whereas C-reactive protein was not. Acute presentation of ROCM was commoner in CAM. Involvement of brain and orbit were similar between groups. Multivariate analysis revealed that steroid use was independently associated with CAM (OR 28.4; p=0.001). CONCLUSION: The current Indian mucormycosis epidemic (mostly acute ROCM) was precipitated by a unique confluence of risk factors – diabetes mellitus, widespread use of steroids, and the COVID-19 infection itself. Restricting steroid use to patients with severe COVID-19 requiring oxygen therapy, screening for and optimally controlling hyperglycaemia can prevent CAM in a large majority.