Intra-arterial spread of Mucormycetes mediates early ischemic necrosis of brain and suggests new venues for prophylactic therapy

Mucormycosis in Human Immunodeficiency Virus-Infected Individuals: A Systematic Review of Case Reports

Mucormycosis in human immunodeficiency virus (HIV) infection is uncommon; notably, many cases have additional predisposing factors. Whether mucormycosis differs in HIV-affected individuals with and without additional risk factors (e.g., neutropenia, diabetes mellitus, and transplantation) remains unclear. In this systematic review, we identified 94 cases of HIV and mucormycosis classifiable into three groups: (1) HIV with additional risk factors (n = 50), (2) intravenous drug users (IVDU, n = 24), and (3) no other risk factor (n = 19) for mucormycosis. The most common presentation in IVDU was renal (41.7%) and cerebral mucormycosis (39.2%), whereas rhino-orbital mucormycosis (ROM, 4.2%) was uncommon. In the other two groups, ROM was the most common presentation. Rhizopus was the most frequently isolated Mucorales; however, in IVDU, Lichtheimia was the most common. The overall mortality was 53% and not significantly different in the three groups. Mucormycosis in HIV-infected individuals is rare without additional risk factors or IVDU.

COVID-19-Associated Rhino-Orbital Mucormycosis in a Tertiary Health Care Center in Odisha, India

Background Mucormycosis is an opportunistic infection that mainly affects immunocompromised individuals, including those with uncontrolled diabetes, malignancies, or those who have exposure to high-dose corticosteroids for a long time. Western Odisha, India, witnessed a significant rise in post-COVID-19 rhino-orbital mucormycosis (ROM), which created a need for comprehensive research on post-COVID-19 ROM. Objective This study aimed to investigate the prevalence, clinical characteristics, and outcomes of post-COVID-19 ROM in a tertiary care hospital in Western Odisha, India, with the objective of understanding ROM as a nationally notifiable disease. Subjects and methods A prospective hospital-based study was conducted. Mucormycosis cases were reported within the period, from May 17, 2021, to July 31, 2021, including all post-COVID-19 patients who exhibited clinical manifestations of mucormycosis. Patients with histopathologically negative reports of mucormycosis were excluded. Results Of the 35 included, 25 were diagnosed with ROM. The age group of 46-50 years showed a predominance (n=6), with a mean age of 50.53 years. The male-to-female ratio was 2:1. Specifically, 88% of the patients included had diabetes mellitus, 8% had chronic kidney diseases, 8% had sepsis, and 4% had hypertension. ROM was the predominant manifestation (60%, n=15), with the majority presenting with orbital cellulitis (80%), followed by unilateral orbital apex syndrome (12%), bilateral orbital apex syndrome (4%), ophthalmic vein involvement (4%), and osteomyelitis of the maxillary sinus (4%). Irrigation of the wound was performed, and all 25 ROM patients received IV liposomal amphotericin B (L-AMB). Conclusion Post-COVID-19 status with elevated blood sugar levels was a major risk factor for ROM. Early diagnosis, debridement, L-AMB, retrobulbar AMB deoxycholate, and exenteration are the possible solutions.

Antibody responses and CNS pathophysiology of Mucormycosis in Chronic SARS CoV-2 infection: Current Therapies against Mucormycosis

The incidence rate of opportunistic secondary infections through invasive fungi has been observed to be 14.5% to 27% in the SARS CoV pandemic during the year 2003. But, the incidence of SARS CoV-2 is accompanied by the substantial rise in secondary opportunistic infections like mucormycosis (black fungus) mainly in the immunocompromised individuals, and diabetic patients taking steroids. Substantial rates of COVID-19 cases with mucormycosis were reported in India and other parts of the world. Previous research reports delineated the ability of Mucorales in invading the various tissues like lungs, brain, sinus through the GRP78 and subsequently this infection could invoke crusting, edema, and necrosis of brain parenchyma, ptosis, proptosis, and vision loss due to intraorbital & intracranial complications. Similarities of these pathophysiological complications with already existing diseases are causing clinicians to face several challenges in order to diagnose and treat this disease effectively at the early stage. This minireview depicts the mucormycosis-induced immune, and pathophysiological alterations in COVID-19 patients comorbid with diabetes, immunosuppression, and also reported the various clinical manifestations, and the therapeutic modalities and the failures of anti-fungal vaccines. Therefore, the emerging mucormycosis in COVID-19 patients need a rapid investigation and selective optimization of the effective therapeutic modalities including antifungal vaccines to minimize mortality rate.

Mucormycosis: An opportunistic pathogen during COVID-19

The pandemic of coronavirus disease 2019 (COVID-19) still remains on an upsurge trend. The second wave of this disease has led to panic in many countries, including India and some parts of the world suffering from the third wave. As there are no proper treatment options or remedies available for this deadly infection, supportive care equipment's such as oxygen cylinders, ventilators and heavy use of steroids play a vital role in the management of COVID-19. In the midst of this pandemic, the COVID-19 patients are acquiring secondary infections such as mucormycosis also known as black fungus disease. Mucormycosis is a serious, but rare opportunistic fungal infection that spreads rapidly, and hence prompt diagnosis and treatment are necessary to avoid high rate of mortality and morbidity rates. Mucormycosis is caused by the inhalation of its filamentous (hyphal form) fungi especially in the patients who are immunosuppressed. Recent studies have documented alarming number of COVID-19 patients with mucormycosis infection. Most of these patients had diabetes and were administered steroids for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and were consequently more prone to mucormycosis. Hence, the present review emphasizes mucormycosis and its related conditions, its mechanism in normal and COVID-19 affected individuals, influencing factors and challenges to overcome this black mold infection. Early identification and further investigation of this fungus will significantly reduce the severity of the disease and mortality rate in COVID-19 affected patients.

A closer look at pathogenesis of cerebral mucormycosis in diabetic condition: A mini review

Patients with diabetes are considered a high-risk group involved with cerebral mucormycosis (CM). Due to the potential of Mucorales to invade sinuses and its rapid progression into orbit and retro-orbital areas and even brain, in most cases, CM is fatal in patients with diabetes. In the last few decades, mucormycosis and background conditions responsible for the development of its infections have received a great deal of attention. Dysfunction of innate and adaptive immune system, the increased amount of available nutrition, expression of host factors, and free iron level in plasma in diabetic ketoacidosis are among the topics that have been mostly taken into account so far. Therefore, it is important to clarify the molecular mechanisms that let the Mucorales to involve the patients with diabetes, which even at early stages of diagnosis and treatment, there is minimum chance to control the disease.

Mucormycosis of the Central Nervous System

Mucormycosis involves the central nervous system by direct extension from infected paranasal sinuses or hematogenous dissemination from the lungs. Incidence rates of this rare disease seem to be rising, with a shift from the rhino-orbital-cerebral syndrome typical of patients with diabetes mellitus and ketoacidosis, to disseminated disease in patients with hematological malignancies. We present our current understanding of the pathobiology, clinical features, and diagnostic and treatment strategies of cerebral mucormycosis. Despite advances in imaging and the availability of novel drugs, cerebral mucormycosis continues to be associated with high rates of death and disability. Emerging molecular diagnostics, advances in experimental systems and the establishment of large patient registries are key components of ongoing efforts to provide a timely diagnosis and effective treatment to patients with cerebral mucormycosis.