COVID-19-Associated Mucormycosis: An Opportunistic Fungal Infection. A Case Series and Review

Abstract

Background: A surge in COVID-19-associated mucormycosis cases has been observed during the second wave of COVID-19 in summer of 2021. Most cases were reported from India. The Delta variant (B.1.617.2) was the most common variant circulating at that time. Mucormycosis is an opportunistic angioinvasive fungal infection with high morbidity and mortality.

Methods: We present 10 cases of COVID-19-associated rhino-orbital and rhino-orbital-cerebral mucormycosis managed in a secondary hospital in Oman.

Results: The median time for developing mucormycosis was two weeks after COVID-19 diagnosis. All patients were newly diagnosed or already known to have poorly controlled diabetes mellitus. Five patients received corticosteroid therapy for COVID-19. Three patients had severe COVID-19 and died of severe acute respiratory distress syndrome and septic shock. Another three patients died of advanced mucormycosis and cerebral involvement. Despite aggressive medical and surgical intervention, the mortality rate was 60% (6/10).

Conclusion: Mucormycosis is an aggressive opportunistic infection with high morbidity and mortality that requires prompt recognition and urgent intervention. Uncontrolled blood sugar, the use of corticosteroids, and immune dysfunction due to COVID-19 are all important risk factors for development of mucormycosis. Worse outcomes are associated with poor glycemic control despite aggressive medical and surgical interventions.

Keywords: COVID-19 associated mucormycosis; COVID-19 variants; Invasive mold infections; Mucorales; Rhino-orbital-cerebral mucormycosis; Rhizopus oryzae.

Figure 1

A. Hard palate grossly involved with the disease. Black eschar is visible. B. Pre-operative endoscopic view of right-side posterior nasal cavity. C. Fungal hyphae growth in post-operative nasal cavity. D. Maxillary sinus mucosa appears pale and sloughy. E. Imprint smear showing broad, ribbon-like and twisted, non-septate fungal hyphae displaying right-angled branching (Hematoxylin and Eosin 200X). F. Histopathological section showing perineural infiltration by broad wide-angled branching fungal hyphae (Hematoxylin and Eosin 400X). G. Coronal computed tomography (CT) image shows unilateral mucosal thickening of left maxillary and left ethmoid sinuses. H. Axial CT image shows unilateral left nasal cavity and maxillary sinus mucosal thickening. There is soft tissue infiltration of left anterior periantral fat. I. Dilated right superior ophthalmic vein. J. Axial CT head shows right sided fronto-parietal ischemic infarct.