A Narrative Review of the Pathophysiology of Mucormycosis Infection Among COVID-19 Patients in India: Epidemiology and Clinical Implications

Abstract

Background and Objective: During the second COVID-19 wave in India (April to May 2021), mucormycosis has affected the ‘recovering’ and the ‘recovered but vulnerable’ COVID-19 patients across the country. This review synthesizes information on the risk factors and pathophysiology of mucor infection among COVID-19 patients, which in turn supplements existing information from public health and clinical sciences. The study objective includes analyzing the morbidity of mucor infection and its pathophysiological mechanism, during India’s second wave of the COVID-19 pandemic. Methods: We conducted a systematic literature search of PubMed and Google Scholar databases, using the following text terms: ‘COVID-19,’ ‘SARS-CoV-2,’ ‘mucormycosis,’ and ‘zygomycosis.’ We identified 24 citations and 16 other published literature which described mucormycosis in association with COVID-19. The relevant literature was analyzed for findings on the risk factors of mucor infection and its outcome among individuals with COVID-19. Results: The risk factors for mucor infection include diabetes mellitus, immunosuppression (for example, the administration of steroids/monoclonal antibodies/broad-spectrum antibiotics), prolonged stay in the intensive care unit, co-morbidities such as malignancy or post-transplantation, and prophylactic therapy with voriconazole (generic anti-fungal). The second wave of COVID-19 in India was more severe due to the increased occurrence of systemic inflammation and coagulopathy, which can cause direct damage to the blood vessels resulting in injuries to organs such as the liver, kidney, and heart. Conclusion and Implications for Translation: The increased incidence of mucormycosis during the second wave of the COVID-19 pandemic in India (April to May 2021) was due to a combination of immunocompromising effects of corticosteroids, microangiopathy of diabetes, and peripheral microthrombi among COVID-19 patients. The indiscriminate usage of steroids for treating COVID-19 disease seems to be the likely cause, including the use of immunomodulatory drugs such as interleukin 6 inhibitors like tocilizumab (TCZ) for patients with severe COVID-19. Clinical practices should adopt a judicious approach towards the prescription of steroids and monitoring blood sugar for all COVID-19 patients admitted to the hospital as well as those isolated at home (even during the post-recovery period). The high mortality rate of mucor infection demands appropriate primary prevention measures, as well as early diagnosis and treatment modalities for improving patient survival.