COVID-19-Associated mucormycosis: Case series from a tertiary care hospital in South India

Abstract

The pandemic coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) is a global health problem. COVID-19 has given rise to a number of secondary bacterial or fungal infections. During the second wave of COVID-19, India experienced an epidemic of mucormycosis in COVID-19 patients. In this paper, we discuss the clinical features, investigations and management of four patients having COVID-19-associated mucormycosis (CAM), especially rhino-orbital mucormycosis (ROM) caused by Rhizopus arrhizus and Mucor species. We also compare the cases and their risk factors with previously reported CAM cases in India. Three patients had mucormycosis after recovering from COVID-19. They were successfully treated with surgical debridement and early initiation of anti-fungal therapy with systemic amphotericin B and other supportive measures such as broad-spectrum antibiotics, insulin infusion, antihypertensives and analgesics. The remaining patient had mucormycosis during COVID-19. He was admitted in the intensive care unit due to COVID-pneumonia and was on mechanical ventilation. In spite of all supportive measures, the patient succumbed to death due to cardiogenic shock. Three out of our four patients had diabetes mellitus. All patients were treated with systemic steroid during COVID-19 treatment. Diabetes mellitus and steroid treatment are the major risk factors for CAM. Early diagnosis of this life-threatening infection along with strict control of hyperglycemia is necessary for optimal treatment and better outcomes.

Keywords: COVID-19; Diabetes mellitus; Mucorales; Mucormycosis; Rhino-orbital mucormycosis; Rhizopus arrhizus.

Fig. 1.

MRI brain and orbit of cases 1, 2 and 3. Case 1 : [1A,1C] Axial and coronal T2W MRI showing mucosal thickening in right maxillary and bilateral ethmoidal sinuses. [1B] T2 fat sat axial MRI showing inflammatory changes of right orbital soft tissue extending to orbital apex, pre-septal/ peri-orbital region with proptosis of right globe suggestive of right maxillary and ethmoidal sinusitis with orbital extension. Case 2 : [1D,1F] Axial and coronal T2W MRI showing hetero intense mucosal thickening in bilateral ethmoid, maxillary and sphenoid sinuses. [1E] T2 fat sat axial MRI showing mild right eye proptosis with right orbital soft tissue inflammatory changes- suggestive of orbital extension. Case 3 : [1G,1I] Axial and coronal T2W MRI showing mucosal thickening of maxillary and ethmoidal sinuses with complete opacification of the left maxillary sinus. [1H ] T2 fat sat axial MRI showing left maxillary sinusitis with retro antral soft tissue inflammatory changes involving masticator space and pterygopalatine fossa suggestive of invasive sinusitis.

Fig. 2.

Histopathology of tissue specimens of cases with Haematoxylin and Eosin staining showing broad aseptate hyphae with wide-angle branching (a, b), necrotic tissue showing broad aseptate fungal hyphae (c, e, f), broad fungal hyphae with acute inflammatory background (d). [Case-1: Fig. 2a, b; Case 2: Fig. 2c, d; Case 3: Fig. 2e, f].

Fig. 3.

Direct (×400) microscopy (with 10 % KOH mount) of tissue specimens showing broad aseptate fungal hyphae with wide angle branching similar to Mucorales. (Fig. 3a, b are the KOH mount of case 1 and case 2, respectively).

Fig. 4.

LPCB staining of cases. Case 1: [5A] Aseptate fungal hyphae with sporangiophores ending in terminal sporangia. Rhizoids are absent (×100). [5B] Sporangia filled with sporangiospores (×400). Case 2: [5C,5D] Long aseptate sporangiophores originating from stolon opposite to rhizoids (×100). Case 3: [5E] Aseptate erect sporangiophores ending in terminal sporangium (×400). Case 4: [5F] ‘Rhizoids’ – root-like structure at under points where sporangiophore develop (×400). All our figures are available in Figshare [1].

Fig. 5.

Fungal culture showing white cotton-candy like growth on SDA medium incubated at 25 °C and 37 °C. The left and right figures show the obverse and reverse sides of the tubes, respectively. No pigmentation is seen on the reverse sides of the tubes.