Mucormycosis due to Apophysomyces species complex- 25 years' experience at a tertiary care hospital in southern India

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.

Mucormycosis during COVID-19 era: A retrospective assessment

In a retrospective view, this review examines the impact of mucormycosis on health workers and researchers during the COVID era. The diagnostic and treatment challenges arising from unestablished underlying pathology and limited case studies add strain to healthcare systems. Mucormycosis, caused by environmental molds, poses a significant threat to COVID-19 patients, particularly those with comorbidities and compromised immune systems. Due to a variety of infectious Mucorales causes and regionally related risk factors, the disease's incidence is rising globally. Data on mucormycosis remains scarce in many countries, highlighting the urgent need for more extensive research on its epidemiology and prevalence. This review explores the associations between COVID-19 disease and mucormycosis pathology, shedding light on potential future diagnostic techniques based on the fungal agent's biochemical components. Medications used in ICUs and for life support in ventilated patients have been reported, revealing the challenge of managing this dual onslaught. To develop more effective treatment strategies, it is crucial to identify novel pharmacological targets through "pragmatic" multicenter trials and registries. In the absence of positive mycology culture data, early clinical detection, prompt treatment, and tissue biopsy are essential to confirm the specific morphologic features of the fungal agent. This review delves into the history, pathogens, and pathogenesis of mucormycosis, its opportunistic nature in COVID or immunocompromised individuals, and the latest advancements in therapeutics. Additionally, it offers a forward-looking perspective on potential pharmacological targets for future drug development.

Invasive Non-Candida Fungal Infections in Acute Burns-A 13-Year Review of a Single Institution and Review of the Literature

The past decade has demonstrated increased burn wound infections with atypical invasive fungal organisms. The range of previously regiospecific organisms has expanded, and plant pathogens are increasingly represented. Our institution sought to examine changes in severe fungal non-Candida infections in our patients, via retrospective review of patients admitted to our burn center from 2008 to 2021. We identified 37 patients with atypical invasive fungal infections. Non-Candida genera included Aspergillus (23), Fusarium (8), Mucor (6), and 13 cases of 11 different species, including the second-ever human case of Petriella setifera. Three fungi were resistant to at least one antifungal. Concomitant infections included Candida (19), Staphylococcus and Streptococcus (14), Enterococcus and Enterobacter (13), Pseudomonas (9), and 14 additional genera. Complete data was available for 18 patients, who had a median of 3.0 (IQR 8.5, range 0-15) additional bacteria required a median of 1 (IQR 7, range 0-14) systemic antibacterials and 2 (IQR 2.5, range 0-4) systemic antifungals. One case of total-drug-resistant Pseudomonas aeruginosa required bacteriophage treatment. One case of Treponema pallidum was found in infected burn wound tissue. Every patient required Infectious Disease consultation. Eight patients became bacteremic and one developed Candida fermentatifungemia. There were five patient deaths (13.8%), all due to overwhelming polymicrobial infection. Burn patients with atypical invasive fungal infections can have severe concomitant polymicrobial infections and multidrug resistance with fatal results. Early Infectious Disease consultation and aggressive treatment is critical. Further characterization of these patients may provide better understanding of risk factors and ideal treatmentpatterns.

Traumatic mucormycosis caused by Apophysomyces species - A case series

Background

Apophysomyces species are emerging as the second most common agent of mucormycosis in India. It is worrisome as it affects predominantly immunocompetent host unlike other Mucorales. Unfortunately, the most common presentation is necrotising fasciitis which can be overlooked as bacterial infection.

Results

Seven cases of mucormycosis due to Apophysomyces species were detected in our hospital between January 2019 and September 2022. Mean age was 55 years and all were males. Six patients presented with necrotising soft tissue infection following accidental or iatrogenic trauma. In four cases, multiple fractures over the body were observed. Median days between admission to laboratory diagnosis was 9 days. All isolates were phenotypically identified as Apophysomyces variabilis. Multiple wound debridements, on an average two, was performed in all the cases and amputation performed in two patients. Three patients recovered, two could not be treated due to financial constraints and lost to followup and two patients died.

Conclusion

Through this series, we anticipate to upheave awareness among the orthopedician community about this emerging infection and contemplate it in appropriate case settings. All patients with necrotising soft tissue infection following trauma and significant degree of wound contamination with soil should be suspected for traumatic mucormycosis at the time of wound assessment.

Overcoming clinical challenges in the management of invasive fungal infections in low- and middle-income countries (LMIC)

INTRODUCTION

The management of invasive fungal infections (IFIs) in low- and middle-income countries (LMIC) is a serious challenge due to limited epidemiology studies, sub-optimal laboratory facilities, gap in antifungal management training and resources. Limited studies highlighted distinctive epidemiology of IFIs in those countries, and difficulty in distinguishing from closely related infections. To overcome the gaps for appropriate management of IFIs, innovative approaches are required.

AREAS COVERED

Extensive literature search and discussion with experts have helped us to summarize the epidemiology, diagnostic and management difficulties in managing IFIs in LMIC, and recommend certain solutions to overcome the challenges.

EXPERT OPINION

The strategies to overcome the challenges in diagnosis may include local epidemiology study, training of healthcare workers, association of fungal infections with already existing budgeted national programs, development and incorporation of point-of-care test (POCT) for prompt diagnosis, simplifying clinical diagnostic criteria suitable for LMIC, judicious use of available expertise, and diagnostic stewardship. For management strategies judicious use of antifungal, partnering with industry for inexpensive antifungal agents, development of LMIC specific guidelines for cost-effective management of IFIs and fungal outbreaks, improvement of infection control practices, advocacy for implementation of WHO recommended antifungal use, and integration of IFIs with public health.

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.

Mucormycosis caused by Apophysomyces species: An experience from a tertiary care hospital in Western India and systematic review of global cases

Apophysomyces species are an emerging cause of mucormycosis in several regions of the world, primarily affecting immunocompetent individuals. The present study addresses the global epidemiology, clinical presentation, management and outcome of mucormycosis caused by Apophysomyces spp. The study included patients diagnosed with Apophysomyces infection at our hospital between March 2019 and August 2020. In addition, cases published in PubMed and Google Scholar from inception to July 2022 were systematically searched and analysed. Only proven and probable cases that meet the eligibility criteria were included. The Indian cases were compared with those from other countries, and the results were analysed by descriptive statistics. In total, six cases of mucormycosis due to Apophysomyces spp. were diagnosed at our hospital, with additional 250 cases identified through literature search. The main underlying diseases were diabetes mellitus (24%), malignancy (3.2%) and chronic kidney disease (2.8%). The major predisposing factor was trauma (55.6%). Necrotizing fasciitis was the most common (63.2%) clinical presentation. Healthcare-associated mucormycosis accounted for 10.4% of the cases. Globally, A. elegans was the most common species (48.8%), whereas A. variabilis was predominant (86.2%) in India. Surgery was performed in 83.5% of patients. Among those treated with antifungal agents, 98% received amphotericin B and 8.1% received posaconazole. Inappropriate antifungal usage was observed in 12.7%. The overall mortality was 42.3%. A combined medical and surgical management was associated with higher survival. Our study highlights the knowledge gap among physicians regarding this infection. A timely diagnosis and aggressive management can improve the outcomes in such cases.

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.

COVID-19-Associated Mucormycosis: A Matter of Concern Amid the SARS-CoV-2 Pandemic

Mucormycosis is an invasive fungal infection caused by fungi belonging to order Mucorales. Recently, with the increase in COVID-19 infections, mucormycosis infections have become a matter of concern globally, because of the high morbidity and mortality rates associated with them. Due to the association of mucormycosis with COVID-19 disease, it has been termed COVID-19-associated mucormycosis (CAM). In the present review, we focus on mucormycosis incidence, pathophysiology, risk factors, immune dysfunction, interactions of Mucorales with endothelial cells, and the possible role of iron in Mucorales growth. We review the limitations associated with current diagnostic procedures and the requirement for more specific, cost-effective, convenient, and sensitive assays, such as PCR-based assays and monoclonal antibody-based assays for the effective diagnosis of mucormycosis. We discuss the current treatment options involving antifungal drug therapies, adjunctive therapy, surgical treatment, and their limitations. We also review the importance of nutraceuticals-based therapy for the prevention as well as treatment of mucormycosis. Our review also highlights the need to explore the potential of novel immunotherapeutics, which include antibody-based therapy, cytokine-based therapy, and combination/synergistic antifungal therapy, as treatment options for mucormycosis. In summary, this review provides a complete overview of COVID-19-associated mucormycosis, addressing the current research gaps and future developments required in the field.

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.

Apophysomyces variabilis, an emerging and worrisome cause of primary cutaneous necrotizing infections in India

In India, Apophysomyces species complex is the second common agent of mucormycosis mainly affecting immunocompetent hosts unlike other Mucorales. It is frequently involved in causing necrotizing cutaneous infections. The present two-year study was planned to investigate the causative role of Apophysomyces spp. in cutaneous necrotizing infections. The tissue samples were processed using standard techniques and in five out of 65 patients, Apophysomyces variabilis was the etiological agent. Diabetes mellitus and trauma were common risk factors and despite appropriate treatment only one patient could be survived. Apophysomyces variabilis is emerging as agent of necrotizing infections which invariably result in poor patient outcomes.

Epidemiology of Mucormycosis in India

Mucormycosis is an angioinvasive disease caused by saprophytic fungi of the order Mucorales. The exact incidence of mucormycosis in India is unknown due to the lack of population-based studies. The estimated prevalence of mucormycosis is around 70 times higher in India than that in global data. Diabetes mellitus is the most common risk factor, followed by haematological malignancy and solid-organ transplant. Patients with postpulmonary tuberculosis and chronic kidney disease are at additional risk of developing mucormycosis in this country. Trauma is a risk factor for cutaneous mucormycosis. Isolated renal mucormycosis in an immunocompetent host is a unique entity in India. Though Rhizopus arrhizus is the most common etiological agent of mucormycosis in this country, infections due to Rhizopus microsporus, Rhizopus homothallicus, and Apophysomyces variabilis are rising. Occasionally, Saksenaea erythrospora, Mucor irregularis, and Thamnostylum lucknowense are isolated. Though awareness of the disease has increased among treating physicians, disease-associated morbidity and mortality are still high, as patients seek medical attention late in the disease process and given the low affordability for therapy. In conclusion, the rise in the number of cases, the emergence of new risk factors and causative agents, and the challenges in managing the disease are important concerns with mucormycosis in India.

Mucormycosis with cutaneous involvement. A retrospective study of 115 cases at a tertiary care hospital in Mexico

BACKGROUND/OBJECTIVES

Cutaneous mucormycosis is an emerging opportunistic mycosis caused by Mucorales. It can be divided into primary caused by trauma and secondary by extension of rhino-cerebral and disseminated cases. The objective is to present a retrospective study of cases of mucormycosis with cutaneous involvement.

METHODS

A retrospective and descriptive study was carried out. Mucormycosis patients were included and divided into two groups: a) Primary Cutaneous and b) Secondary Cutaneous. Mycological tests were performed; the agents were identified by morphology and molecular studies (PCR and sequencing); some cases underwent histopathology. Clinical data and response to treatment were collected.

RESULTS

115 cases were included, 18 of primary, and 97 of secondary cutaneous mucormycosis. Primary cutaneous mucormycosis was most associated with adhesive bands (44.4%) and trauma from traffic accidents (33.3%). The principal clinical form was extensive and deep necrotic ulcers. Secondary cutaneous mucormycosis cases were rhino-cerebral with uncontrolled diabetes (81.4%) The most frequent clinical presentation was necrosis of the eyelid and the nose (65.9%). In both groups, the principal agent was Rhizopus arrhizus, 38.8% and 74.2% respectively. The most effective treatment was the combination of amphotericin B with surgical debridement. The clinical and mycological cure was achieved in 31.0% of primary cases, and 44.4% for secondary cases.

CONCLUSION

Primary cutaneous mucormycosis is caused by implantation of the Mucorales due to trauma or rupture of the cutaneous barrier-breach, and secondary cutaneous mucormycosis develops as part of the rhino-cerebral process. The response to treatment depends on the extension and depth, as well as the predisposing factors.

Combat trauma-related invasive fungal wound infections

Purpose of review

This review highlights research from the past five years on combat trauma-related invasive fungal wound infections (IFIs) with a focus on risk stratification to aid patient management, microbiology, and diagnostics.

Recent Findings

A revised classification scheme stratifies wounds into three risk groups: IFI, High Suspicion of IFI, and Low Suspicion of IFI. This stratification is based on persistence of wound necrosis and laboratory fungal evidence, presence of signs/symptoms of deep soft-tissue infections, and the need for antifungals. Use of this classification could allow for prioritization of antifungal therapy. Further, IFIs delay wound healing, particularly when caused by fungi of the order Mucorales. Lastly, molecular sequencing offers promising and complimentary results to the gold standard histopathology.

Summary

Optimal management of combat-related IFIs depends on early tissue-based diagnosis with aggressive surgical debridement and concomitant dual antifungal therapy. Further research on clinical decision support tools and rapid diagnostics are needed.

Necrotizing fasciitis caused by Apophysomyces variabilis in a burn patient

The genus Apophysomyces belonging to the order Mucorales is increasingly being reported as a cause of mucormycosis in immunocompetent patients. We report a case of necrotizing fasciitis caused by Apophysomyces variabilis in a 52-year-old immunocompetent male who sustained thermal burn in his right leg following a road-traffic accident. There was rapidly progressive necrosis of skin, soft tissues and underlying muscles which required extensive surgical debridement. Microscopic examination of excised tissues revealed broad aseptate fungal hyphae. Fungal culture on Sabouraud dextrose agar (SDA) showed growth of a mucoraceous mould which was identified as A. variabilis based on characteristic microscopic morphology and internal transcribed spacer sequencing of the ribosomal DNA. The isolate was found to sporulate on SDA, a finding that was unique as Apophysomyces spp. does not usually sporulate on primary isolation medium used in mycology laboratories. The disease progressed as there was an initial assumption of bacterial infection and the fungus was isolated late in the course of the disease because of which no antifungal drug was added to the regime. The patient left against medical advice and eventually underwent below-knee amputation at another city hospital a week later. Infection due to A. variabilis should be considered as a differential diagnosis of rapidly progressive necrosis of skin and soft tissues in immunocompetent individuals as early diagnosis and management will prevent the disease progression and a possible amputation.