Mucormycosis, Diabetes and COVID-19 Pneumonia: Unleashing the Facts

Background Mucormycosis (MM) is an angioinvasive locally destructive fungal infection. Before the coronavirus disease 2019 (COVID-19) pandemic, it was associated with diabetes (particularly diabetic ketoacidosis), immunosuppressive drugs and trauma. Among its various forms, cerebral invasion is considered to be highly fatal even if with long-term treatment. Treatment with injection amphotericin B (Amph-B) with early surgical interventions is highly efficacious. Liposomal preparation is considered to be superior in the context of fewer side effects. Methods We present a single-centre prospective study of 124 patients with MM in a tertiary care hospital. After the approval from the ethics committee, basic information was taken from all patients including all available past history about the COVID-19 infection and treatment. The studied outcomes were discharge, death and number of days of hospitalisation. Secondary objectives were to estimate the association of MM with known risk factors, to find the association of an outcome with various inflammatory markers, to determine adverse events with the use of injection Amph-B and posaconazole and to find the case fatality rate of MM. Results In our study, we observed that the number of patients with MM was double in the less than 60 years age group. However, mortality was 33.3% in the elderly as compared to 15.29% in patients less than 60 years of age. The majority of the patients (69.35%) were males, but no significant difference in mortality was seen between males and females. The case fatality rate was 20.97%. Ocular symptoms such as orbital swelling and pain were the common presenting symptoms. Almost all patients (93.54%) were diabetics. The non-diabetic group consisted of only 8 (6.4%) patients, and therefore, the comparison was not possible. A total of 20 (16%) out of 124 patients who had received high-dose steroids showed higher mortality (55%). Maximum patients (65.32%) had presented with MM following a past COVID-19 infection. However, a significant number of MM patients (20.96%) had a recent COVID infection and had higher mortality (57.69%) compared to their counterparts. The most common site of involvement in our study was the paranasal sinus (50%) and the outcome was the best in those patients whose disease was localised only to the sinuses, although among 14 (11.29%) patients with cerebral involvement, mortality was maximum (42.85%). Renal impairment and dyselectrolytemia were the most common adverse effects of Amph-B, and 46.42% of patients required surgical removal of the local part. Conclusion We saw that diabetes was a major contributory factor in the etiopathogenesis of MM. COVID-19 could also be a major causative factor by impairing the immune system; however, further studies at the molecular level are required to establish an association. The use of steroid cannot be the only independent risk factor, and other associated factors must be present. Treatment with antifungal and early surgical intervention had good outcomes. Treatment with conventional lyophilized Amph-B was equally efficacious as lipid-based solutions, but with more side effects. Hypokalemia and hypocalcemia were the most common electrolyte abnormalities associated with the use of injection Amph-B. Uncontrolled diabetes, the severity of the COVID-19 infection at presentation, acidosis, a high C-reactive protein level (above 100) and local brain involvement were associated with a poor outcome.