Clinical Characteristics of 100 Patients With COVID-19-Associated Mucormycosis From a Tertiary Care Center in North India

Preliminary Experience in Post-COVID-19 Mycoses: A Pathologist's Perspective

Background Coronavirus disease is caused by the severe acute respiratory syndrome coronavirus-19. Because of co-morbidities and indiscriminate use of steroids and antibiotics, the incidence of opportunistic fungal infections has increased in COVID-affected individuals. Aims and objectives The aim of the study is to analyze the various tissue reaction patterns of COVID-19-associated mucormycosis in the surgical debridement specimens using routine hematoxylin and eosin (H&E) stain and special stains like periodic acid-Schiff (PAS), Grocott-Gomori's methenamine silver (GMS), Masson trichrome (MT) and Prussian blue (PB), and to understand the pathogenesis of COVID-19 sequelae. Materials and methods This retrospective observational study was conducted after the approval from the Institute Human Ethical Committee (IHEC) on 45 tissue samples of COVID-associated mucormycosis using routine H&E and histochemical stains such as PAS, GMS, MT, and PB. Detailed demographic profiles, clinical information, radiological findings, and relevant microbiological data in available cases, like reports on potassium hydroxide (KOH) mount preparation, and fungal culture reports on Saboraud's Dextrose Agar (SDA) medium were collected. The different histomorphological tissue reaction patterns were observed and analyzed. Results All the surgical debridement specimens from post-COVID cases had histomorphology of mucormycosis displaying broad, aseptate, ribbon-like fungal hyphae with right-angle branching (45/45). Six of the 45 cases also reveal thin, narrow septate, acute angle branching hyphae, indicating co-existing Aspergillosis (6/45). The histological tissue reaction patterns observed were categorized as extensive tissue necrosis (100%), vascular proliferation (82%), angioinvasion (58%), giant cell reaction (53%), fibrin thrombi (47%), septic thrombi and angiodestruction (40%), fungal osteomyelitis (33%), necrotizing granulomas (31%). Conclusion This study infers that post-COVID-19 associated mucormycosis, alterations in the local tissue microenvironment are found to have a favorable effect on colonizing fungi and result in destructive tissue reactions such as angioinvasion, angiodestruction, necrosis, necrotizing granulomas, suppurative inflammation, and iron pigment deposition. The spectrum of morphological changes reflects the host's immune status.

Rhinocerebral Mucormycosis: An Emerging Threat in the Era of COVID-19

Mucormycosis is a rare but aggressive and fatal infection that is prevalent in immunocompromised patients. The variation in its clinical presentation and the lack of specificity are misleading and lead to a delay in the diagnosis and management. However, the era of coronavirus disease 2019 (COVID-19) is marked by the increasing emergence of Mucor infections, now identified as coronavirus-associated mucormycosis (CAM). Although many clinical forms exist, the most encountered in CAM is rhino-orbito-cerebral, as already reported in India.

We present a case of a 56-year-old male patient with uncontrolled diabetes mellitus and a history of recent SARS-CoV-2 infection treated with IV steroids, presenting for maxillary teeth pain and instability on day 16 of COVID-19 infection. Early diagnosis of CAM is crucial and will help decrease mortality in COVID-19 patients, especially those with comorbidities such as diabetes mellitus. Increasing cases of CAM should prompt clinicians to have a high index of suspicion for rhinocerebral mucormycosis, especially in patients with risk factors receiving steroid therapy.

In such patients, baseline glycosylated hemoglobin level and strict glycemic control by frequently measuring blood glucose levels and strictly adhering to insulin protocols would be rational but its efficacy in limiting the numbers of CAM in developing countries still needs to be confirmed.