Study of Profile of Mucormycosis During the Second Wave of COVID-19 in a Tertiary Care Hospital

Role of Posaconazole Drug in the Treatment of Invasive Fungal Disease: A Review

Posaconazole is an antifungal medication used primarily to treat invasive fungal infections caused by various organisms, such as Aspergillus, Candida, and certain molds. It belongs to the class of drugs known as triazole antifungals. Clinical studies have reported posaconazole to be effective in treating various invasive fungal infections, especially in patients who are immunocompromised, such as those with weakened immune systems due to conditions like HIV/AIDS, undergoing chemotherapy, or having received an organ transplant. It has effectively treated invasive candidiasis, aspergillosis, zygomycosis, and other serious fungal infections. The effectiveness of the drug varies based on factors, such as the type of infection, the patient's immune status, and the site of infection. This review describes the types of infection, the drug's safety profile, the development of resistance to posaconazole, and strategies to manage or prevent resistance.

New and emerging roles for inhalational and direct antifungal drug delivery approaches for treatment of invasive fungal infections

INTRODUCTION

The rising prevalence of difficult-to-treat, deep-seated invasive fungal diseases (IFD) has led to high mortality. Currently available antifungal treatments, administered predominantly orally or intravenously, may not sufficiently penetrate certain body sites, and/or are associated with systemic toxicity. Little is known about how to position alternative administration approaches such as inhalational and direct drug delivery routes.

AREAS COVERED

This review provides an updated overview of unconventional drug delivery strategies for managing IFD, focusing on inhalational (to target the lungs) and direct delivery methods to the central nervous system, bone/joint, and eyes. Novel compounds (e.g. opelconazole) and existing antifungals with innovative drug delivery systems currently undergoing clinical trials and/or used off-label in the clinical setting are discussed.

EXPERT OPINION

For both inhalational agents and direct delivery approaches, there are similar challenges that include the absence of: approved formulations for specific administration routes, delivery vehicles that are simple and safe to use whilst maintaining potency and efficiency of delivery, animal models suitable for investigating pharmacokinetic/pharmacodynamic profiles of inhaled antifungals, and consensus on the composite endpoints and intervals for of follow-up in clinical trials. To meet these challenges, cooperation of all stakeholders in drug development and regulation is required.

Sinonasal and Orbital Imaging Findings in COVID-Associated Rhino-Orbito-Cerebral Mucormycosis During the Second Wave of COVID-19: A Retrospective Cohort Study in a Tertiary Hospital in Central India

Background Mucormycosis is a consequence of the angioinvasive disease caused by filamentous fungi that belong to the order Mucorales, particularly Mucor, Rhizopus, and Rhizomucor. Rhizopus oryzae is the most prevalent form. The invading hyphae lead to damage of blood vessels leading to thrombosis and consequent tissue necrosis. The incidence of this disease entity witnessed a significant rise during the second wave of the coronavirus disease 2019 (COVID-19) pandemic. Timely diagnosis and prompt treatment are crucial to diminish both the mortality and morbidity associated with this disease. Imaging plays a pivotal role in diagnosing the ailment, evaluating its extent, identifying complications such as thrombosis, and facilitating surgical planning. It demonstrates exceptional sensitivity in detecting the disease at its early stages, often before symptoms manifest. Due to the angioinvasive nature of Mucor, early detection assumes utmost importance as it necessitates intensive antifungal therapy and the removal of devitalized tissue through debridement. Methodology We conducted a retrospective cohort study to analyze computed tomography (CT) imaging findings in patients with COVID-associated rhino-orbito-cerebral mucormycosis (ROCM) confirmed by histopathological examination. We compared these findings with CT findings of the nose and paranasal sinuses in patients without mucor following COVID-19 sinusitis (non-ROCM). Results All 16 cases in the non-ROCM group were in stage 1 disease. In contrast, in the ROCM group, three patients had stage 1 disease, five patients had stage 2 disease, and 10 patients had stage 3 disease (p = 0.0001). The pterygopalatine fossa was significantly affected in 10 of 18 ROCM patients and in none of the non-ROCM patients. Conclusions Imaging plays a crucial role in the early detection of mucormycosis. It assists treating physicians in initiating prompt and aggressive treatment, thereby improving the prognosis of this frequently fatal disease.

Part 2: Mucormycosis: Focus on Therapy

INTRODUCTION

Mucormycosis (MCR) a rare but life-threatening infection occurs primarily in immunocompromised hosts. Mortality rates with invasive MCR are high (>30-50%), up to 90% with disseminated disease, but lower (10-30%) with localized cutaneous disease. Due to the rarity of MCR, randomized, controlled therapeutic trials are lacking. Lipid formulations of amphotericin B (LFAB) are the mainstay of therapy but oral triazoles (posaconazole and isavuconazole) may be effective as step-down therapy or in MCR cases refractory to or intolerant of LFAB. Early surgical debridement or excision play important adjunctive roles in localized invasive disease. Control of hyperglycemia in diabetic patients, correction of neutropenia and reduction of immunosuppressive therapy is critical for optimal survival.

AREAS COVERED

The authors discuss various therapeutic options for mucormycosis. A literature search of mucormycosis therapies was performed via PubMed (up to December 2022), using the key words: invasive fungal infections; mold; mucormycosis; Mucorales; amphotericin B; isavuconazole; posaconazole.

EXPERT OPINION

Randomized, controlled therapeutic trials are lacking. Lipid formulations of amphotericin B (LFAB) are the mainstay of therapy but oral triazoles (posaconazole and isavuconazole) may be effective as step-down therapy, in MCR cases refractory to or intolerant of LFAB. We encourage early surgical debridement or excision as adjunctive measures.

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.

COVID-19-Associated Fungal Infections: An Urgent Need for Alternative Therapeutic Approach?

Secondary fungal infections may complicate the clinical course of patients affected by viral respiratory diseases, especially those admitted to intensive care unit. Hospitalized COVID-19 patients are at increased risk of fungal co-infections exacerbating the prognosis of disease due to misdiagnosis that often result in treatment failure and high mortality rate. COVID-19-associated fungal infections caused by predominantly Aspergillus and Candida species, and fungi of the order Mucorales have been reported from several countries to become significant challenge for healthcare system. Early diagnosis and adequate antifungal therapy is essential to improve clinical outcomes, however, drug resistance shows a rising trend highlighting the need for alternative therapeutic agents. The purpose of this review is to summarize the current knowledge on COVID-19-associated mycoses, treatment strategies and the most recent advancements in antifungal drug development focusing on peptides with antifungal activity.