COVID-19-Associated Rhino-Orbito-Cerebral Mucormycosis: A Single Tertiary Care Center Experience of Imaging Findings With a Special Focus on Intracranial Manifestations and Pathways of Intracranial Spread

Background and objective The COVID-19 pandemic and mucormycosis epidemic in India made research on the radiological findings of COVID-19-associated mucormycosis imperative. This study aims to describe the imaging findings in COVID-19-associated mucormycosis, with a special focus on the intracranial manifestations.  Methodology Magnetic resonance imaging (MRI) scans of all patients with laboratory-proven mucormycosis and post-COVID-19 status, for two months, at an Indian Tertiary Care Referral Centre, were retrospectively reviewed, and descriptive statistical analysis was carried out. Results A total of 58 patients (47 men, 81%, and 11 women, 19%) were evaluated. Deranged blood glucose levels were observed in 47 (81%) cases. The intracranial invasion was detected in 31 (53.4%) patients. The most common finding in cases with intracranial invasion was pachymeningeal enhancement (28/31, 90.3%). This was followed by infarcts (17/31, 55%), cavernous sinus thrombosis (11/58, 18.9%), fungal abscesses (11/31, 35.4%), and intracranial hemorrhage (5/31, 16.1% cases). The perineural spread was observed in 21.6% (11/51) cases. Orbital findings included extraconal fat and muscle involvement, intraconal involvement, orbital apicitis, optic neuritis, panophthalmitis, and orbital abscess formation in decreasing order of frequency. Cohen's kappa coefficient of interrater reliability for optic nerve involvement and cavernous sinus thrombosis was 0.7. Cohen's coefficient for all other findings was 0.8-0.9. Conclusions COVID-19-associated rhino-orbito-cerebral mucormycosis has a plethora of orbital and intracranial manifestations. MRI, with its superior soft-tissue resolution and high interrater reliability, as elucidated in this study, is the imaging modality of choice for expediting the initial diagnosis, accurately mapping out disease extent, and promptly identifying and scrupulously managing its complications.

A case report on clinical features, diagnosis, and treatment of rhino-orbito-cerebral mucormycosis

BACKGROUND

Rhino-orbito-cerebral mucormycosis (ROCM) is an opportunistic pathogenic fungal disease caused by the fungus mucor, and it is a life-threatening fungal infection. The ulceration on the skin of the head and neck, accompanied by rhinitis, headache, orbital inflammation, and eyelid edema, should raise a high suspicion of Mucor infection in diabetic patients with inadequately controlled blood glucose.

CASE DESCRIPTION

The clinical data of a patient with ROCM were analyzed retrospectively, and the clinical features were analyzed. The patient was admitted to the hospital with "diabetic hyperosmotic coma" after presenting with fatigue, poor appetite, and disturbances in consciousness as initial symptoms. After improving relevant examinations, controlling underlying diseases, and administering antifungal treatment, the final clinical outcome was death.

CONCLUSION

ROCM is more prevalent in patients with uncontrolled diabetes and varied clinical manifestations. The characteristic feature is an eschar-like necrosis of the local skin or mucosa. The gold criteria for diagnosis are pathology and fungal culture; imaging examination does not reveal any specific manifestations. Early diagnosis and effective treatment are the keys.

Mucormycosis co-infection in COVID-19 patients: An update

Mucormycosis (MCM) is a rare fungal disorder that has recently been increased in parallel with novel COVID-19 infection. MCM with COVID-19 is extremely lethal, particularly in immunocompromised individuals. The collection of available scientific information helps in the management of this co-infection, but still, the main question on COVID-19, whether it is occasional, participatory, concurrent, or coincidental needs to be addressed. Several case reports of these co-infections have been explained as causal associations, but the direct contribution in immunocompromised individuals remains to be explored completely. This review aims to provide an update that serves as a guide for the diagnosis and treatment of MCM patients' co-infection with COVID-19. The initial report has suggested that COVID-19 patients might be susceptible to developing invasive fungal infections by different species, including MCM as a co-infection. In spite of this, co-infection has been explored only in severe cases with common triangles: diabetes, diabetes ketoacidosis, and corticosteroids. Pathogenic mechanisms in the aggressiveness of MCM infection involves the reduction of phagocytic activity, attainable quantities of ferritin attributed with transferrin in diabetic ketoacidosis, and fungal heme oxygenase, which enhances iron absorption for its metabolism. Therefore, severe COVID-19 cases are associated with increased risk factors of invasive fungal co-infections. In addition, COVID-19 infection leads to reduction in cluster of differentiation, especially CD4+ and CD8+ T cell counts, which may be highly implicated in fungal co-infections. Thus, the progress in MCM management is dependent on a different strategy, including reduction or stopping of implicit predisposing factors, early intake of active antifungal drugs at appropriate doses, and complete elimination via surgical debridement of infected tissues.

Hit or Miss: The Dilemma of Specimen Selection for Microbiological Diagnosis of Rhino-Orbital-Cerebral- COVID-Associated Mucormycosis (ROCM-CAM)

BACKGROUND

We diagnosed various cases of rhino-orbital-cerebral- COVID-associated Mucormycosis (ROCM-CAM) during India's second wave of COVID-19. This helped formulate novel suggestions for improving laboratory output, applicable anywhere in the world.

METHODS

To diagnose ROCM-CAM by microbiological methods, we used direct microscopy and conventional culture on various clinical samples within the shortest turn-around time.

DESIGN

Prospective single-center observational study.

PARTICIPANTS

Patients with ROCM-CAM.

RESULTS

Of 113 suspected cases of ROCM-CAM during May 2021, direct microscopy and culture could confirm the disease in 87.61% and 44.25% of patients, respectively. The highest pathogen isolation was seen from maxillary bone fragments, FESS-guided biopsy from pterygopalatine fossae, nasal turbinates and nasal mucosal biopsy. Direct microscopy could diagnose the disease in almost 40% of patients within 24 hours and 60% within two days. Conventional cultures yielded Rhizopus spp. (86%) as the commonest fungal pathogen followed by Mucor spp. (12%) within 7 days. Deep tissue biopsies are more useful for rapid diagnosis than superficial specimens. Routine fungal cultures can supplement case detection and help prognosticate survivors.

CONCLUSION

The management of ROCM is a surgical emergency. The diagnosis of the condition must therefore be prompt and precise. Despite ongoing antifungal therapy, nasal mucosal tissue, FESSguided, and intra-operative tissue biopsies showed the pathogen's highest diagnostic yield. The diagnostic index improved further when multiple (4-5) high-quality specimens were collected. Nasal swabs and crusts, among the most commonly requested specimens worldwide, were found to have an overall low diagnostic potential.

The Pathogenetic Dilemma of Post-COVID-19 Mucormycosis in India

There has been a surge of mucormycosis cases in India in the wake of the second wave of COVID-19 with more than 40000 cases reported. Mucormycosis in patients of COVID-19 in India is at variance to other countries where Aspergillus, Pneumocystis, and Candida have been reported to be the major secondary fungal pathogens. We discuss the probable causes of the mucormycosis epidemic in India. Whereas dysglycaemia and inappropriate steroid use have been widely suggested as tentative reasons, we explore other biological, iatrogenic, and environmental factors. The likelihood of a two-hit pathogenesis remains strong. We propose that COVID-19 itself provides the predisposition to invasive mucormycosis (first hit), through upregulation of GRP78 and downregulation of spleen tyrosine kinase involved in anti-fungal defense, as also through inhibition of CD8+ T-cell mediated immunity. The other iatrogenic and environmental factors may provide the second hit which may have resulted in the surge.

COVID-19 associated Mucormycosis (CAM): risk factors and mechanisms of disease

The severe surge of COVID-19 cases in the Indian subcontinent in early 2021 was marked by an unusually high number of cases of COVID-19 associated mucormycosis (CAM) reported during this period. This is significantly higher than predicted based on available data about prevalence or risk factors for this condition. This may be from an unusual alignment of multiple risk factors for this condition. There is high background prevalence of mucormycosis in India probably from high prevalence of risk factors, including undiagnosed or poorly controlled diabetes. COVID-19 induced immune dysregulation, and immune suppression from steroid therapy increase the risk. The role of environmental exposure is unclear. System factors like lack of access to healthcare during a pandemic may result in delayed diagnosis or suboptimal management with potentially poor outcomes. This is a review of currently identified risk factors and pathogenesis of CAM in a pandemic surge.

Rhino-orbital mucormycosis following COVID-19 in previously non-diabetic, immunocompetent patients

PURPOSE

To report a series of 13 immunocompetent patients who developed new-onset uncontrolled diabetes mellitus (DM) following COVID-19 infection and presented as rhino-orbital mucormycosis (ROM).

METHOD

Retrospective study.

RESULTS

A total of 127 patients of COVID-19 Associated Mucormycosis (CAM) were evaluated at four centres in India. All patients underwent endoscopic sinus debridement surgery and received systemic amphotericin-B therapy. Five patients (5/13; 38.4%) received retrobulbar amphotericin-B injections. Orbital exenteration was performed in advanced orbital involvement or progression of orbital disease in spite of maximal medical therapy. In his cohort, 13/127 (10.2%) patients presented with new onset DM, where one patient had bilateral disease. The mean age was 35.9 years (range: 20-51 years) and the mean duration from diagnosis of COVID-19 to the diagnosis of mucormycosis was 14.2 days. While 7/13 (53.8%) of the patients received systemic corticosteroids during the course of their treatment for COVID-19, six patients received no steroids or immunomodulators. The mean follow-up period was 9.2 weeks (range: 3-18 weeks) following discharge. Life salvage was possible in 100% of the cases. While overall globe salvage was possible in 42.8% (6/14 eyes), the globe could be preserved in 4/5 patients who received retrobulbar amphotericin-B injections.

CONCLUSIONS

Those involved in the care of COVID-19 patients should be aware about the possibility of recent-onset DM, even in patients without a history of corticosteroid therapy. Rarely, recent-onset DM following COVID-19 may present as rhino-orbital mucormycosis, which requires aggressive surgical and medical intervention.

Mucormycosis: The Scathing Invader

Mucormycosis is an invasive fungal infection that has been increasing in incidence over the years. Increase in the number of diabetics, malignancy patients, and use of immunosuppressants has mainly led to this gradual upward surge. Mucormycosis has various clinical forms, including rhino-orbito-cerebral, pulmonary, gastrointestinal, and cutaneous. Fungi belonging to Mucorales are thermotolerant and ubiquitous, found growing on organic substrates such as bread, decaying fruits and vegetables, crop debris in soil, compost, and animal excreta. During this second wave of the COVID-19 pandemic, the number of cases of mucormycosis has increased manifold in a short span of time. Associated comorbidity of diabetes mellitus, increased use of higher doses and prolonged duration of systemic corticosteroids, the glucogenic and prothrombotic propensity of the virus, hypoxic environment, COVID pneumonia, increased hospitalization, ICU admissions, and mechanical ventilation have all contributed toward this high rise in numbers. The rhin-orbito-cerebral form is the commonest manifestation of mucormycosis in COVID. Rhizopus oryzae, the main species causing mucormycosis, is identified by hyaline, sparsely-septate, broad, ribbon-like hyphae with irregular right-angle branching ribbon-like hyphae with rhizoids. For the early diagnosis of this infection, 10% KOH mount is very important. These fungi are very rapidly growing and thus can be differentiated from their main ally, Aspergillus. Treatment is mainly in the form of extensive surgical debridement along with liposomal amphotericin B. Posaconazole and isavuconazole are second-line agents, which can also be used for maintenance. Control of diabetes and COVID-19, along with judicious use of antibiotics and systemic corticosteroids, are equally important as management strategies in these pandemic times.

Managing mucormycosis in diabetic patients: A case report with critical review of the literature

BACKGROUND AND PURPOSE

Rhino-orbito-cerebral mucormycosis (ROCM) is a rare and potentially fatal invasive fungal infection which usually occurs in diabetic and other immunocompromised patients. This infection is associated with high morbidity and mortality rates. Prompt diagnosis and rapid aggressive surgical debridement and antimycotic therapy are essential for the patient's survival. Herein, we reviewed the localization and treatment strategies in patients with ROCM and diabetes as an underlying condition. Furthermore, we report one case of ROCM in our department.

MATERIALS AND METHODS

From 117 identified studies published in PubMed, 14 publications-containing data from 54 patients-were included. All patients were diagnosed clinically and by histopathological and/or bacteriological analysis for ROCM caused by the order Mucorales.

CONCLUSION

Uncontrolled diabetes mellitus is one of the main risk factors for ROCM. A successful management of ROCM requires an early diagnosis, a prompt systemic antifungal therapy, and a rapid aggressive surgical debridement including exploration of the pterygopalatine fossa. An orbital exenteration may be necessary.

A Fatal Outcome of Rhino-orbito-cerebral Mucormycosis Following Tooth Extraction: A Case Report

Rhino-orbito-cerebral mucormycosis is an uncommon aggressive life-threatening opportunistic fungal infection that affects mainly the immunocompromised population with mortality rate up to 50%. Due to its aggressive nature, early detection and prompt management are of great importance for a good prognosis. Our report describes a fatal outcome of a case of rhino-orbito-cerebral mucormycosis following tooth extraction in an uncontrolled non-insulin-dependent diabetes mellitus patient after 14 days of admission.