Mucormycosis in COVID-19 pandemic: Risk factors and linkages

Mucormycosis: A Rare disease to Notifiable Disease

Mucormycosis is the third most frequent invasive mycosis, following candidiasis and aspergillosis. It is frequently neglected due to its rare occurrence; but recently attend the status of notifiable disease due to its higher incidence in both developed and developing nations. India has received global notice since its estimated instances were greater than the global estimated figures. Mucormycosis has several clinical manifestations, including rhino-orbital-cerebral (ROCM), pulmonary, gastrointestinal, cutaneous, renal, and diffuse Mucormycosis. ROCM is the most frequent clinical manifestation in India, although pulmonary mucormycosis is prevalent worldwide. This review also discusses host defenses, pre disposing risk factors and fungal virulence factors that impair host's ability to prevent fungus invasion and disease establishment. The diagnosis of the disease depends on clinical interventions, histological or microbiological procedures along with molecular methods to obtain timely results. But there are still unmet challenges for rapid diagnosis of the disease. Treatment of the disease is achieved by multimodal approaches such as reversal of underlying predisposing factors, rapid administration of antifungals in optimal doses and surgical procedures to remove infected tissues. Liposomal Amphotericin B, Posaconazole and Isavuconazoles are preferred as the first line of treatment procedures. clinical trials. Different studies have improved the existing drug and under clinical trials while several studies predicted the new potential targets as CotH and Ftr1 as shown in infection and in vitro models. Therefore, current scenario demands a multidisciplinary approach is needed to investigate the prevalence, pathogenesis which is highly important for the advancement of rapid diagnosis and effective treatment.

Comprehensive Review on the Virulence Factors and Therapeutic Strategies with the Aid of Artificial Intelligence against Mucormycosis

Mucormycosis, a rare but deadly fungal infection, was an epidemic during the COVID-19 pandemic. The rise in cases (COVID-19-associated mucormycosis, CAM) is attributed to excessive steroid and antibiotic use, poor hospital hygiene, and crowded settings. Major contributing factors include diabetes and weakened immune systems. The main manifesting forms of CAM─cutaneous, pulmonary, and the deadliest, rhinocerebral─and disseminated infections elevated mortality rates to 85%. Recent focus lies on small-molecule inhibitors due to their advantages over standard treatments like surgery and liposomal amphotericin B (which carry several long-term adverse effects), offering potential central nervous system penetration, diverse targets, and simpler dosing owing to their small size, rendering the ability to traverse the blood-brain barrier via passive diffusion facilitated by the phospholipid membrane. Adaptation and versatility in mucormycosis are facilitated by a multitude of virulence factors, enabling the pathogen to dynamically respond to various environmental stressors. A comprehensive understanding of these virulence mechanisms is imperative for devising effective therapeutic interventions against this highly opportunistic pathogen that thrives in immunocompromised individuals through its angio-invasive nature. Hence, this Review delineates the principal virulence factors of mucormycosis, the mechanisms it employs to persist in challenging host environments, and the current progress in developing small-molecule inhibitors against them.

Atypical and Unpredictable Superficial Mycosis Presentations: A Narrative Review

While typically exhibiting characteristic features, fungal infections can sometimes present in an unusual context, having improbable localization (eyelid, face, or joint); mimicking other skin diseases such as eczema, psoriasis, or mycosis fungoides; and appearing with unexpected color, shape, or distribution. The emergence of such a challenging clinical picture is attributed to the complex interplay of host characteristics (hygiene and aging population), environment (climate change), advances in medical procedures, and agent factors (fungal resistance and species emergence). We aim to provide a better understanding of unusual epidemiological contexts and atypical manifestations of fungal superficial diseases, knowing that there is no pre-established clinical guide for these conditions. Thus, a literature examination was performed to provide a comprehensive analysis on rare and atypical superficial mycosis as well as an update on certain fungal clinical manifestations and their significance. The research and standard data extraction were performed using PubMed, Medline, Scopus, and EMBASE databases, and a total of 222 articles were identified. This review covers published research findings for the past six months.

COVID-19 associated mucormycosis surge: A review on multi-pathway mechanisms

Mucormycosis is a fungal infection caused by moulds from the Mucorales order. Concerns have been mounting due to the alarming increase in severe morbidity and mortality associated with mucormycosis during the COVID-19 pandemic. This condition, known as COVID-19-associated mucormycosis (CAM), has been linked to various environmental, host-related, and medical factors on a global scale. We have categorized the most significant potential risk factors for developing mucormycosis in individuals with a previous history of coronavirus infection into 10 major categories. These categories include acute hyperglycemia, the impact of cytokine release, immune response deficiencies in COVID-19 patients, microvasculopathy and dysfunction of endothelial cells, imbalances in iron metabolism, metabolic acidosis, organ damage resulting from COVID-19, underlying health conditions (such as diabetes), environmental factors, and medical treatments that can be iatrogenic in nature (such as inappropriate glucocorticoid use). Many of these factors can lead to potentially life-threatening infections that can complicate the treatment of COVID-19. Physicians should be vigilant about these factors because early detection of mucormycosis is crucial for effective management of this condition.

The Second COVID-19 Wave Is a Tsunami With Aftershocks: Mucormycosis Ire as Seen in a Tertiary Care Hospital in Uttarakhand, India

BACKGROUND

During the spread of severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) or the coronavirus disease 2019 (COVID-19) pandemic in recent times, an upsurge of invasive fungal infections (IFIs) such as mucormycosis was witnessed by many countries like India. This COVID-19-associated mucormycosis (CAM) has presented as a menace to the already creaking health infrastructure. Clinical manifestations, risk factors, and end clinical outcomes varied for every other region/country. The aim of this study is to delineate and analyze plausible clinical and epidemiological factors and associated predictors of CAM in suspected patients presenting to a tertiary care hospital in Uttarakhand, India, during the second wave of COVID-19 in India.

MATERIAL AND METHODS

A total of 200 cases of suspected post‑COVID-19 mucormycosis were enrolled. Data were collected taking into account parameters such as hospitalization and ICU admissions during the episode of COVID-19 infection, steroid/antibiotics/oxygen requirement, and comorbidities such as diabetes mellitus, hypertension, or any chronic illness and outcome.

RESULTS

Participants diagnosed with CAM using KOH examination and fungal culture were analyzed in the study (n=46). The median age of patients included was 48, 73.9% were males, and 26% were females. The major predisposing factor was found to be diabetes mellitus type 2. Our work suggests that the mean duration between COVID-19 episodes and CAM was 11.86 days with a significant statistical association. Oxygen requirement and imprudent use of steroids/antibiotics were also allied with mucormycosis.

CONCLUSION

The burden of such IFIs is expected to be unveiled in tropical countries during pandemics such as COVID-19, which lead to immunosuppression in masses post-treatment. Comorbidities such as diabetes, chronic kidney disease, and hypertension add to the risk of acquiring other infectious disease. Such times require competent healthcare professionals such as diagnosticians, physicians, and surgeons who are skilled to manage such IFIs timely.

Rhinocerebral Mucormycosis Following COVID-19 Infection in Iran

Background & Objective

Mucormycosis (also called black fungus) is an opportunistic serious fungal infection caused by mucormycetes. It can occur in diabetes mellitus patients and other immunosuppressive conditions with recent predisposing factors such as maxillofacial surgery and corticosteroid usage.

Methods

In this study, 14 patients were referred to the otorhinolaryngology or ophthalmology ward of Shafa Hospital (Kerman, Iran) with primary symptoms of nasal fullness and facial nerve dysfunction; they were admitted to the hospital to rule out the fungal infection. An endoscopic biopsy was taken from facial sinuses or orbit, and a microscopic evaluation was performed using hematoxylin and eosin (H&E) and periodic acid-Schiff (PAS) staining methods to rule out mucormycosis.

Results

In the histopathological examination, broad-based nonseptate branching fungal hyphae were found in nasal sinuses through the endoscopic biopsy. Most of the patients had diabetes mellitus with a primary symptom of facial nerve palsy; also, most of them received corticosteroids (intravenous [IV] or intramuscular [IM] injection). All patients have recently been infected with COVID-19 (less than 1 month ago).

Conclusion

COVID-19 infection might be a predisposing factor for many opportunistic infections, such as fungal elements); thus, the physician should be aware of the dosage and duration of corticosteroid therapy to prevent the development of these infections.

A case of COVID-19-associated mucormycosis due to Lichtheimia ramosa

BACKGROUND

Mucormycosis is a life-threatening invasive fungal infection in immunocompromised and COVID-19 patients.

CASE REPORT

Here, we report a fatal rhino-orbito-cerebral mucormycosis caused by Lichtheimia ramosa, in a 79-year-old diabetic female. She was initially admitted to the hospital for COVID-19 infection and received broad-spectrum antibiotics and corticosteroids. After 1 month, she was admitted again because of persistent headaches and decreased right eye movement when the computed tomography scan showed mucosal thickening and opacification of paranasal sinuses. Microbiological investigations, including culture and direct microscopy, and histopathological findings confirmed the diagnosis of proven mucormycosis. The isolated causal agent was identified as Lichtheimia ramosa by sequencing the entire ITS region of nuclear ribosomal DNA. Despite surgical debridement and administration of liposomal amphotericin B 5 mg/kg/day, the patient's level of consciousness suddenly deteriorated; she was intubated and mechanically ventilated in the ICU and died on the same day.

CONCLUSION

To our knowledge, this is the first worldwide case of COVID-19-associated rhino-orbito-cerebral mucormycosis due to Lichtheimia ramosa.

Epidemiology of COVID-19-Associated Mucormycosis

Purpose of the Review

To describe the epidemiology and risk factors for Coronavirus disease-19 (COVID-19)-associated mucormycosis (CAM) based on current published literature.

Recent Findings

COVID-19 is associated with an increased risk of secondary infections. Mucormycosis is an uncommon invasive fungal infection that typically affects people with immunocompromising conditions and uncontrolled diabetes. Treatment of mucormycosis is challenging and is associated with high mortality even with standard care. During the second wave of the COVID 19 pandemic, an abnormally high number of CAM cases were seen particularly in India. Several case series have attempted to describe the risk factors for CAM.

Summary

A common risk profile identified for CAM includes uncontrolled diabetes and treatment with steroids. COVID-19-induced immune dysregulation as well as some unique pandemic specific risk factors may have played a role.

Current management of diabetes patients with COVID-19

INTRODUCTION

Diabetes mellitus (DM) and the 2019 coronavirus (COVID-19) appear to interact in both directions. There is mounting proof that patients with DM have a worse COVID-19 prognosis than those without it. Pharmacotherapy is also known to affect in view of the possible interplay between drugs and the pathophysiology of the above conditions in a given patient.

AREAS COVERED

In this review, we discuss the pathogenesis of COVID-19 and its connections with diabetes mellitus. We also analyze the treatment modalities for COVID-19 and diabetes patients. The possible mechanisms of the different medications and their management limitations are also systematically reviewed.

EXPERT OPINION

COVID-19 management as well as its knowledge base is changing constantly. The Pharmacotherapy and the choice of drugs also need to be specifically considered in view of the concomitant presence of these conditions in a patient. Anti-diabetic agents must be carefully evaluated in diabetic patients in view of the disease's severity, blood glucose level, appropriate treatment, and other components that could aggravate adverse events. A methodical technique is anticipated to enable the safe and rational use of drug therapy in COVID-19-positive diabetic patients to take.

Pathogenesis and Pathology of COVID-Associated Mucormycosis: What Is New and Why

Purpose of Review

There is global increase in the incidence of mucormycosis. However, a sudden increase in the COVID-associated mucormycosis (CAM) was noted, particularly in India, during the second wave of the COVID-19 pandemic. The interplay of factors involved in the pathogenesis is complex. In this review, the influence of pre-existing disease, exaggerated risk factors, altered milieu due to COVID-19 itself and the consequences of its treatment on the host pathogen interactions leading to the disease and morphology of the fungus will be highlighted.

Recent Findings

Hyperglycemia, acidosis, available free iron, lowered host defenses, and the fungal virulence factors promote the growth of Mucorales. There is a high background prevalence of diabetes mellitus (DM) in India. Uncontrolled or undiagnosed DM, COVID-19 itself, and inappropriate administration of corticosteroids in high doses and for prolonged periods result in hyperglycemia. Diabetic ketoacidosis (DKA) and metabolic acidosis due to hypoxia or renal failure contribute to acidic pH and dissociate bound iron from serum proteins. The host defenses are lowered due to COVID-19-induced immune dysregulation, hyperglycemia itself, and administration of corticosteroids and immune suppressants for the treatment of COVID-19. The altered metabolic milieu in the local microenvironment of nose and paranasal sinuses (PNS) promotes specific interaction of glucose-regulated protein-78 (GRP-78) on host cells with spore coat protein homologue (CotH 3) on Mucorales resulting in rhino-orbito-cerebral mucormycosis (ROCM) as the predominant clinical form in CAM. The pathology is extensive soft tissue involvement with angioinvasion and perineural invasion. Melanized hyphae and sporangia were seen on histopathology, which is unique to CAM. While many factors favor the growth of Mucorales in CAM, hyperglycemia, hyperferritinemia, and administration of hyperbaric oxygen result in reactive oxygen species (ROS) and inadequate humidification results in dehydration. Melanization is possibly the adaptive and protective mechanism of Mucorales to escape the unfavorable conditions due to the treatment of COVID-19.

Summary

High background prevalence of DM, inappropriate administration of corticosteroids and immune dysregulation due to COVID-19 favor the growth of Mucorales in CAM. Melanization of Mucorales hyphae and sporangia on histopathology probably represent adaptive and protective mechanism due to the treatment with hyperbaric oxygen with inadequate humidification as well as the metabolic alterations.

Dietary diversity as a sustainable approach towards micronutrient deficiencies in India

The silent epidemic of micronutrient deficiencies (MNDs) continues to be a major public health challenge in the developing world, including India. The prevalence of iron, iodine, zinc, vitamin A and folate deficiencies is alarmingly high worldwide. India is additionally facing a high prevalence of vitamin D and B12 deficiencies. To combat the hidden epidemic of MNDs, various governments around the world have mostly relied on supplementation or fortification-based interventions. India launched salt iodization programme in 1962 and vitamin A and iron-folate supplementation programmes in 1970. Yet, even after decades of these programmes, MNDs are still widespread in the country. Due to slow progress in alleviating the burden of most MNDs, the Government of India aims to scale up fortification-based intervention programmes. However, there are safety and effectiveness concerns with such approaches. Hence, overdependence on supplementation and fortification alone may be counterproductive. Instead, food based dietary diversification approach can be the way forward. In this article, we list the common MNDs in India, evaluate major policy interventions, discuss concerns pertaining to fortification and suggest the need for a concurrent food-based approach, in particular dietary diversification, as a long-term and sustainable strategy to address population-based MNDs.

The Co-infection of Mild COVID-19 and Rhinocerebral Mucormycosis in a Patient Without Diabetes or Prior Steroid Use

In a fast-evolving COVID-19 pandemic, co-infection with mucormycosis has been reported in some parts of the world. It is still unknown whether one of the either diseases makes the patient susceptible to developing the other. The co-occurrence of them significantly elevates the mortality risk and is commonly reported in immunocompromised individuals. We herein report a case of COVID-19 infection with rhinocerebral mucormycosis without prior steroid use or underlying immunosuppressive diseases.

COVID-19-Related Rhino-Orbito-Cerebral Mucormycosis Complicated by the Optic Nerve and Optic Tract Ischemia With Ischemic Neuropathy

Mucormycosis is a life-threatening invasive fungal infection usually seen in immunocompromised patients and patients with poorly controlled diabetes mellitus with or without diabetic ketoacidosis. We present a rhino-orbito-cerebral mucormycosis (ROCM) case in a coronavirus disease 2019 (COVID-19) patient complicated by the optic nerve and optic tract ischemia with ischemic neuropathy. Both CT and MRI played an essential role in diagnosing ROCM and the accompanying complications in our patient.

CT showed sinonasal sinusitis and MRI showed the sinusitis and its progression to ROCM. MRI also showed necrosis involving the bilateral orbits, basal ganglia, thalamus, internal capsule, hypothalamus, optic chiasm, optic nerves, olfactory bulbs, and skull base. ROCM associated with optic nerve ischemia is a rare but life-threatening complication of COVID-19, especially in patients with underlying diabetes and/or those treated with corticosteroids. Physicians should be aware of this complication as early diagnosis may improve the chances of survival in such patients.

Interleukin-37: A Link Between COVID-19, Diabetes, and the Black Fungus

The COVID-19 pandemic involved millions of people and diabetes was identified as an associated comorbidity. Initiation of systemic corticosteroids in patients suffering from severe COVID-19 was associated with lower mortality. A surge of invasive fungal infections of the maxillofacial region, namely mucormycosis, was linked to a deadly infection known as black fungus. Black fungus, diabetes, corticosteroids, and coronavirus disease 2019 (COVID-19) all have a dysregulated immune response in common, which partly could also be attributed to interleukin 37 (IL-37). IL-37, a new cytokine of the IL-1 family, known for broadly reducing innate inflammation as well as acquired immune responses. The use of corticosteroids in diabetic COVID-19 patients, crowded hospitals, and lack of medical oxygen should be carefully considered to reduce COVID-associated secondary infections.

COVID-19-associated mucormycosis of head-and-neck region: A systematic review

BACKGROUND AND AIM

With the second wave of COVID-19, there has been a substantial rise in opportunistic infections like mucormycosis. Mucormycosis is a fatal fungal infection and understanding the associated risk factors and their management plays a key role to reduce mortality and morbidity caused due to such infections. This systematic review was conducted to assess the risk factors, clinical characteristics and to understand the pathogenesis of COVID-19-associated mucormycosis (CAM) affecting the head-and-neck region.

METHODS

The PubMed database was searched with the keywords; ((Mucormycosis) OR (invasive fungal sinusitis)) AND (COVID-19) and the PRISMA chart was prepared for the selection of the reports based on the inclusion and exclusion criteria.

RESULTS

A total of 261 cases of CAM affecting the head-and-neck region were analyzed in this systematic review. Most of the patients presented with rhino-orbital/rhino-orbito-cerebral form of mucormycosis (rhino-orbital mucormycosis/rhino-orbital-cerebral mucormycosis). Pulmonary mucormycosis along with rhino-orbital form, involvement of hard palate, and maxillary sinus was seen in one case each. A total of 224 (85.8%) patients were diabetic, 68 (30.3%) of them had poor glycemic control. Steroids were administered in 210 (80.4%) patients. Except for two, antifungal treatment was given to all patients. Follow-up data revealed 67 (25.6%) deaths and 193 (73.9%) were alive with one patient lost during follow-up.

CONCLUSION

The findings of this systematic review suggested that the occurrence of mucormycosis in COVID-19 patients is related to the inherent effects of COVID-19 infection on the immune system, comorbidities especially diabetes, and treatment aspects. Hence, a detailed understanding of these factors may aid in the personalized management of CAM and improve the disease outcome.

RELEVANCE FOR PATIENTS

The risk factors in patients affected by CAM should be recognized and closely monitored in post-COVID-19 patients. A multidisciplinary team must be in place to reduce the mortality and morbidity in such patients.

Dental and Oral Manifestations of COVID-19 Related Mucormycosis: Diagnoses, Management Strategies and Outcomes

It has been nearly two years since the pandemic caused by the novel coronavirus disease (COVID-19) has affected the world. Several innovations and discoveries related to COVID-19 are surfacing every day and new problems associated with the COVID-19 virus are also coming to light. A similar situation is with the emergence of deep invasive fungal infections associated with severe acute respiratory syndrome 2 (SARS-CoV-2). Recent literature reported the cases of pulmonary and rhino-cerebral fungal infections appearing in patients previously infected by COVID-19. Histopathological analysis of these cases has shown that most of such infections are diagnosed as mucormycosis or aspergillosis. Rhino-orbital-cerebral mucormycosis usually affects the maxillary sinus with involvement of maxillary teeth, orbits, and ethmoidal sinuses. Diabetes mellitus is an independent risk factor for both COVID-19 as well as mucormycosis. At this point, there is scanty data on the subject and most of the published literature comprises of either case reports or case series with no long-term data available. The aim of this review paper is to present the characteristics of COVID-19 related mucormycosis and associated clinical features, outcome, diagnostic and management strategies. A prompt diagnosis and aggressive treatment planning can surely benefit these patients.

Identifying Mucormycosis Severity in Indian COVID-19 Patients: A Nano-Based Diagnosis and the Necessity for Critical Therapeutic Intervention

The COVID-19 infection caused by the new SARS-CoV-2 virus has been linked to a broad spectrum of symptoms, from a mild cough to life-threatening pneumonia. As we learn more about this unusual COVID-19 epidemic, new issues are emerging and being reported daily. Mucormycosis, also known as zygomycosis or phycomycosis, causes severe fungal illness to individuals with a weakened immune system. It is a devastating fungal infection, and the most frequent kind is the rhino cerebral type. As a devastating second wave of COVID-19 sweeps India, doctors report several instances involving a strange illness-sometimes known as the "black fungus"-among returning and recovered COVID-19 patients. This paper analyzes the existing statistical data to address the severity of prevalence and further notes the nano-based diagnostic parameters, clinical presentations, its connection with other conditions like diabetes, hypertension, and GI disorders, and the importance of anti-fungal therapy in treating the same. Anti-fungal therapies, as well as surgical interventions, are currently used for the treatment of the disease. Proper and timely diagnosis is necessary, along with the reduction in the spread of COVID-19. From the review, it was found that timely pharmacologic interventions and early diagnosis by using a nano-based diagnostic kit can help control the disease. Additionally, this paper provides novel information about the nanotechnology approaches such as fungal detection biosensors, nucleic acids-based testing, point-of-care tests, and galactomannans detection, in the diagnosis of mucormycosis, and thereby reinforces the need for further research on the topic.

Is there an association between zinc and COVID-19-associated mucormycosis? Results of an experimental and clinical study

BACKGROUND

The enormous increase in COVID-19-associated mucormycosis (CAM) in India lacks an explanation. Zinc supplementation during COVID-19 management is speculated as a contributor to mucormycosis. We conducted an experimental and clinical study to explore the association of zinc and mucormycosis.

METHODS

We inoculated pure isolates of Rhizopus arrhizus obtained from subjects with CAM on dichloran rose Bengal chloramphenicol (DRBC) agar enriched with (three different concentrations) and without zinc. At 24 h, we counted the viable colonies and measured the dry weight of colonies at 24, 48 and 72 h. We also compared the clinical features and serum zinc levels in 29 CAM cases and 28 COVID-19 subjects without mucormycosis (controls).

RESULTS

We tested eight isolates of R arrhizus and noted a visible increase in growth in zinc-enriched media. A viable count percentage showed a significantly increased growth in four of the eight isolates in zinc-augmented DRBC agar. A time- and concentration-dependent increase in the mean fungal biomass with zinc was observed in all three isolates tested. We enrolled 29 cases of CAM and 28 controls. The mean serum zinc concentration was below the reference range in all the subjects and was not significantly different between the cases and controls.

CONCLUSIONS

Half of the R arrhizus isolates grew better with zinc enrichment in vitro. However, our study does not conclusively support the hypothesis that zinc supplementation contributed to the pathogenesis of mucormycosis. More data, both in vitro and in vivo, may resolve the role of zinc in the pathogenesis of CAM.

Risk Factors for Mucormycosis in COVID-19 Patients

: Opportunistic infections, such as mucormycosis, in coronavirus disease 2019 (COVID-19) patients has become a new health challenge. Since opportunistic infections can exacerbate COVID-19 patients' status, it is vital to identify the risk factors to prevent, diagnose, and treat them as soon as possible. Viral, fungal, environmental, and host factors may be responsible for this situation. Long hospital stays, impaired host immune system function due to viral infection, and excessive consumption of glucocorticoids in managing COVID-19 patients are the main risk factors for the increased risk of mucormycosis in COVID-19 patients. Educating health care workers and considering the association between mucormycosis of the paranasal sinuses and different strains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as the cause of COVID-19 can help prevent invasive fungal sinusitis in COVID-19 patients.