Recent Advances in Diagnostic Approaches for Mucormycosis

Mucormycosis, an invasive fungal infection caused by members of the order Mucorales, often progresses fulminantly if not recognized in a timely manner. This comprehensive review discusses the latest developments in diagnostic approaches for mucormycosis, from traditional histopathology and culture-based methods to advanced and emerging techniques such as molecular assays, imaging, serology, and metabolomics. We discuss challenges in the diagnosis of mucormycosis and emphasize the importance of rapid and accurate identification of this life-threatening infection.

Concordance of Chest Radiography and Chest Computed Tomography Findings in Patients with Hematologic Malignancy and Invasive Mucormycosis: What Are the Prognostic Implications?

Invasive pulmonary mucormycosis (IPM) is a deadly opportunistic mold infection in patients with hematological malignancies (HM). Radiologic imaging is essential for its timely diagnosis. Here, we compared IPM lesions visualized by chest computed tomography (CCT) and chest X-ray (CXR) and determined the prognostic significance of discordant imaging. Therefore, we reviewed 44 consecutive HM patients with probable/proven IPM at MD Anderson Cancer Center in 2000-2020 who had concurrent CCT and CXR studies performed. All 44 patients had abnormal CCTs and 39 (89%) had anormal CXR findings at IPM diagnosis. However, only 26 patients (59%) showed CCT-matching IPM-suspicious lesions on CXR. Acute Physiology and Chronic Health Evaluation II score > 18 at IPM diagnosis and breakthrough infection to Mucorales-active antifungals were the only independent risk factors for 42-day and/or 84-day mortality. Absence of neutropenia at IPM diagnosis, neutrophil recovery in neutropenic patients, and surgical revision of mucormycosis lesions were protective factors. Although not reaching significance on multivariable analysis, visualization of CCT-matching lesions on CXR was associated with significantly increased 84-day mortality (log-rank test, p = 0.033), possibly as a surrogate of extensive lesions and tissue necrosis. This observation supports the exploration of radiologic lesion kinetics as a prognostic staging tool in IPM patients.

Risk Factors and Outcomes of Mucorales Infection in a Modern Cohort of Solid Organ Transplant, Hematopoietic Cell Transplant, and Chimeric Antigen Receptor T-cell Therapy Recipients

BACKGROUND

Mucorales infections continue to cause significant morbidity and mortality in immunocompromised hosts despite the advent of new approaches for diagnosis and treatment of fungal infections. We aimed to evaluate risk factors and outcomes of Mucorales infection in solid organ transplant, hematopoietic cell transplant, and chimeric antigen receptor T-cell therapy recipients.

METHODS

This single-center retrospective study included solid organ transplant, hematopoietic cell transplant, and chimeric antigen receptor T-cell patients with cultures positive for Mucorales.

RESULTS

Forty-three patients were included for analysis; 34 solid organ transplant (79%) and 9 hematopoietic stem cell transplant or chimeric antigen receptor T-cell (21%). Infection with Mucorales occurred a median of 184 days after transplant. At the time of diagnosis, 36 patients were on antifungal prophylaxis with the majority receiving posaconazole (53%). Thirty-three had clinically significant disease; 30 received definitive anti-Mucorales therapy and 3 empiric antifungal therapy. Isavuconazole was the most common azole used for treatment in monotherapy recipients. All-cause mortality was 64% and, of these deaths, 18 (75%) were directly related to Mucormycosis. The highest mortality was seen in disseminated and intra-abdominal disease (100%), followed by pulmonary disease (50%). There was no significant association with mortality and transplant type or number of immunosuppressive agents.

CONCLUSION

Mucormycosis is an important cause of morbidity and mortality in immunocompromised patients. Breakthrough infection was not uncommon in this study. Data regarding the incidence of infection at approximately 6 months after transplantation can inform prophylaxis and treatment regimens. The spectrum of antifungal regimens used reflects the lack of consensus on ideal regimens for these organisms and a need for more studies.

Co-Existing Fungi: An Unforeseen Combo Creating a Dilemma in Diagnostic Morale

Mucormycosis is a rare fungal infection belonging to Mucorales order fungi. Rhino-cerebral form is more noted in patients with diabetes mellitus, but pulmonary mucormycosis is a rare manifestation with hematological malignancy, malignant tumors, and transplant recipient patients. Aspergillus species are also known to cause allergic bronchopulmonary aspergillosis, aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis in immunocompromised individuals. We report a case of pulmonary mucormycosis superimposed with aspergillus infection presenting in an immunocompromised patient with metastatic prostate cancer on chemotherapy, initially misdiagnosed as aspergillus infection.

Practical issues related to non-Aspergillus invasive mold infections

Infection by non-Aspergillus molds has been increasingly reported. The management of such infections is challenging both for diagnosis and treatment, including the need of well-trained mycologists to properly identify rare fungi, difficulties in distinguishing between contamination, colonization and infection, the lack of randomized studies comparing different drugs or regimens, poor activity of available antifungal agents, lack of correlation between in vitro antifungal susceptibility tests and clinical outcome, and poor prognosis. Mucormycosis and fusariosis are the most frequent non-Aspergillus mold infections. Mucormycosis occurs more frequently in four major groups of patients: solid organ transplant recipients, patients with hematologic malignancies receiving chemotherapy or hematopoietic cell transplantation, diabetic patients, and immunocompetent individuals who suffer various types of skin and soft tissue trauma. Invasive fusariosis occurs almost exclusively in patients with hematologic malignancies. In this review we discuss practical issues related to the management of these and other non-Aspergillus mold infections.

Improving Diagnosis of Pulmonary Mucormycosis: Leads From a Contemporary National Study of 114 Cases

BACKGROUND

Pulmonary mucormycosis (PM) is a life-threatening invasive mold infection. Diagnosis of mucormycosis is challenging and often delayed, resulting in higher mortality.

RESEARCH QUESTION

Are the disease presentation of PM and contribution of diagnosis tools influenced by the patient's underlying condition?

STUDY DESIGN AND METHODS

All PM cases from six French teaching hospitals between 2008 and 2019 were retrospectively reviewed. Cases were defined according to updated European Organization for Research and Treatment of Cancer/Mycoses Study Group criteria with the addition of diabetes and trauma as host factors and positive serum or tissue PCR as mycologic evidence. Thoracic CT scans were reviewed centrally.

RESULTS

A total of 114 cases of PM were recorded, including 40% with disseminated forms. Main underlying conditions were hematologic malignancy (49%), allogeneic hematopoietic stem cell transplantation (21%), and solid organ transplantation (17%). When disseminated, main dissemination sites were the liver (48%), spleen (48%), brain (44%), and kidneys (37%). Radiologic presentation included consolidation (58%), pleural effusion (52%), reversed halo sign (26%), halo sign (24%), vascular abnormalities (26%), and cavity (23%). Serum quantitative polymerase chain reaction (qPCR) was positive in 42 (79%) of 53 patients and BAL in 46 (50%) of 96 patients. Results of transthoracic lung biopsy were diagnostic in 8 (73%) of 11 patients with noncontributive BAL. Overall 90-day mortality was 59%. Patients with neutropenia more frequently displayed an angioinvasive presentation, including reversed halo sign and disseminated disease (P < .05). Serum qPCR was more contributive in patients with neutropenia (91% vs 62%; P = .02), and BAL was more contributive in patients without neutropenia (69% vs 41%; P = .02). Serum qPCR was more frequently positive in patients with a > 3 cm main lesion (91% vs 62%; P = .02). Overall, positive qPCR was associated with an early diagnosis (P = .03) and treatment onset (P = .01).

INTERPRETATION

Neutropenia and radiologic findings influence disease presentation and contribution of diagnostic tools during PM. Serum qPCR is more contributive in patients with neutropenia and BAL examination in patients without neutropenia. Results of lung biopsies are highly contributive in cases of noncontributive BAL.

Atypical imaging patterns during lung invasive mould diseases: lessons for clinicians

Imaging of pulmonary invasive mould diseases (IMDs), which represents a cornerstone in their work-up, is mainly based on computed tomography (CT). The purpose of this review is to discuss their CT features, mainly those related to aspergillosis and mucormycosis. We will especially focus on atypical radiological presentations that are increasingly observed among non-neutropenic emerging populations of patients at risk, such as those receiving novel anticancer therapies or those in the intensive care unit. We will also discuss the interest of other available imaging techniques, mainly positron emission tomography/CT, that may play a role in the diagnosis as well as evaluation of disease extent and follow-up. We will show that any new airway-centred abnormality or caveated lesion should evoke IMDs in mildly immunocompromised hosts. Limitations in their recognition may be due to potential underlying abnormalities that increase the complexity of interpretation of lung imaging, as well as the non-specificity of imaging features. In this way, the differentials of all morphological/metabolic aspects must be kept in mind for the optimal management of patients, as well as the benefit of evaluation of the vascular status.

Mucormycosis in 2023: an update on pathogenesis and management

Mucormycosis (MCR) is an emerging and frequently lethal fungal infection caused by the Mucorales family, with Rhizopus, Mucor, and Lichtheimia, accounting for > 90% of all cases. MCR is seen in patients with severe immunosuppression such as those with hematologic malignancy or transplantation, Diabetes Mellitus (DM) and diabetic ketoacidosis (DKA) and immunocompetent patients with severe wounds. The recent SARS COV2 epidemy in India has resulted in a tremendous increase in MCR cases, typically seen in the setting of uncontrolled DM and corticosteroid use. In addition to the diversity of affected hosts, MCR has pleiotropic clinical presentations, with rhino-orbital/rhino-cerebral, sino-pulmonary and necrotizing cutaneous forms being the predominant manifestations. Major insights in MCR pathogenesis have brought into focus the host receptors (GRP78) and signaling pathways (EGFR activation cascade) as well as the adhesins used by Mucorales for invasion. Furthermore, studies have expanded on the importance of iron availability and the complex regulation of iron homeostasis, as well as the pivotal role of mycotoxins as key factors for tissue invasion. The molecular toolbox to study Mucorales pathogenesis remains underdeveloped, but promise is brought by RNAi and CRISPR/Cas9 approaches. Important recent advancements have been made in early, culture-independent molecular diagnosis of MCR. However, development of new potent antifungals against Mucorales remains an unmet need. Therapy of MCR is multidisciplinary and requires a high index of suspicion for initiation of early Mucorales-active antifungals. Reversal of underlying immunosuppression, if feasible, rapid DKA correction and in selected patients, surgical debulking are crucial for improved outcomes.

Mucormycosis: A 14-Year Retrospective Study from a Tertiary Care Center in Lebanon

Mucormycosis (MCM) is a serious invasive fungal disease (IFD) that is associated with high mortality, particularly in immunocompromised patients. A global surge in MCM cases was reported with the COVID-19 pandemic. We analyzed all recorded cases of MCM at the American University of Beirut Medical Center (AUBMC), a tertiary care center in Lebanon, over 14 years. We aimed to identify the incidence, seasonal variation, clinical characteristics of the patients, and predictors of mortality. We conducted a retrospective chart review between 1 January 2008 and 1 January 2023. All patients with proven or probable MCM were included in the study. Proven or probable MCM was defined by positive histopathology and/or positive cultures. A total of 43 patients were identified as having MCM. Their median age was 53 years, and the majority were males (58.1%). Most of the cases were diagnosed in the autumn season. In total, 67.4% of the patients had hematological malignancies (HMs), and 34.9% had uncontrolled diabetes mellitus (DM). The most common site of involvement was rhino-orbital-cerebral MCM (ROCM) (74%). The annual cases of MCM per 100,000 patient days increased markedly during the years of the COVID-19 pandemic (from 0 to 4.4 cases/100,000 patient days to 7.5 cases/100,000 during 2020 and 2021). Liposomal amphotericin (Ampho) B was used as a first-line agent in most of the patients (86%). The median duration of total in-hospital antifungal therapy was 21 days and 51.2% of the patients received step-down therapy with azoles. Surgical debridement and isolated ROCM were significantly associated with survival (p-value: 0.02 and <0.001, respectively). All-cause mortality was 46.7%, with chronic renal disease being significantly associated with mortality (p-value < 0.05). The incidence of MCM has been increasing at our institution, particularly since the COVID-19 pandemic. Early diagnosis, treatment, and surgical debridement improve patient outcomes and overall survival.

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.

Novel Approaches in the Management of Mucormycosis

Purpose of Review

Invasive mucormycosis (IM), caused by fungi of the order Mucorales, is one of the deadliest fungal infection among hematologic cancer patients. Its incidence is also increasingly reported in immunocompetent individuals, notably with the COVID-19 pandemic. Therefore, there is an urgent need for novel diagnostic and therapeutic approaches of IM. This review discusses the current advances in this field.

Recent Findings

Early diagnosis of IM is crucial and can be improved by Mucorales-specific PCR and development of lateral-flow immunoassays for specific antigen detection. The spore coat proteins (CotH) are essential for virulence of the Mucorales and may represent a target for novel antifungal therapies. Adjuvant therapies boosting the immune response, such as interferon-γ, anti-PDR1 or fungal-specific chimeric antigen receptor (CAR) T-cells, are also considered.

Summary

The most promising perspectives for improved management of IM consist of a multilayered approach targeting both the pathogen and the host immune system.

Rhizopus homothallicus, an emerging pathogen causing cavitary lung lesions

Introduction

Rhizopus homothallicus is an emerging pathogen that causes pulmonary mucormycosis.

Case Presentation

We report a case of pneumonia caused by R. homothallicus in a 54-year-old type 2 diabetic patient. The organism was isolated from bronchoalveolar lavage fluid and preliminarily identified by fungal morphology and finally by sequencing of the internal transcribed spacer region.

Conclusion

Mucormycosis may be associated with cavitary lung lesions against a backdrop of poorly controlled diabetes or other immunosuppressed states. Pulmonary mucormycosis may have variable clinical and radiological presentations. Therefore, strong clinical suspicion and prompt management can address the high fatality associated with the disease.

The Fragile Patient: Considerations in the Management of Invasive Mould Infections (IMIs) in India

Invasive mould infections (IMIs), which are mostly caused by Aspergillus spp. and Mucormycetes, are opportunistic infections that impose a substantial threat to patients who are considered to be 'fragile'. There is no fixed definition for fragile patients; however, patients with cancer or acquired immunodeficiency syndrome (AIDS), patients who have undergone organ transplants, and patients being treated in the intensive care units (ICUs) were considered fragile. Management of IMIs in fragile patients is challenging, owing to their compromised immune status. The diagnostic challenges associated with IMIs due to insufficient sensitivity and specificity of the current diagnostic tests lead to delayed treatment. A widening demographic of at-risk patients and a broadening spectrum of pathogenic fungi have added to the challenges to ascertain a definite diagnosis. A recent surge of mucormycosis associated with SARS-CoV-2 infections and the resultant steroid usage has been reported. Liposomal amphotericin B (L-AmB) is the mainstay for treating mucormycosis while voriconazole has displaced amphotericin B as the mainstay for treating Aspergillus infection due to its better response, improved survival, and fewer severe side effects. The selection of antifungal treatment has to be subjected to more scrutiny in fragile patients owing to their comorbidities, organ impairment, and multiple ongoing treatment modalities. Isavuconazole has been documented to have a better safety profile, stable pharmacokinetics, fewer drug-drug interactions, and a broad spectrum of coverage. Isavuconazole has thus found its place in the recommendations and can be considered a suitable option for treating fragile patients with IMIs. In this review, the authors have critically appraised the challenges in ascertaining an accurate diagnosis and current management considerations and suggested an evidence-based approach to managing IMIs in fragile patients.

A peek behind the curtain in the diagnosis and management of COVID‑19‑Associated Mucormycosis (CAM)

Coronavirus disease 2019 (COVID-19)-associated mucormycosis (CAM) is responsible for a high mortality rate due to its unique and severe host-pathogen interactions. Critically ill or immunocompromised COVID-19 patients are more prone to suffer from aggressive mycoses. Probable victims include those with uncontrolled diabetes mellitus (DM), metabolic acidosis, prolonged neutropenia, increased ferritin levels, hypoxia, and prolonged hospitalization with/without mechanical ventilators and corticosteroids administration. The current review aims to outline the journey of patients with CAM as well as the advantages and disadvantages of the currently available diagnostic techniques. It also discussed the current status of treatment options and caveats in the management of mucormycosis. Multidisciplinary team, early diagnosis, controlling the predisposing condition(s), complete surgical debridement, effective antifungal therapies (e.g., amphotericin B, isavuconazole, and posaconazole), and implementing antifungal stewardship programs are imperative in CAM cases.

What Is New in Pulmonary Mucormycosis?

Mucormycosis is a rare but life-threatening fungal infection due to molds of the order Mucorales. The incidence has been increasing over recent decades. Worldwide, pulmonary mucormycosis (PM) presents in the lungs, which are the third main location for the infection after the rhino-orbito-cerebral (ROC) areas and the skin. The main risk factors for PM include hematological malignancies and solid organ transplantation, whereas ROC infections are classically favored by diabetes mellitus. The differences between the ROC and pulmonary locations are possibly explained by the activation of different mammalian receptors—GRP78 in nasal epithelial cells and integrin β1 in alveolar epithelial cells—in response to Mucorales. Alveolar macrophages and neutrophils play a key role in the host defense against Mucorales. The diagnosis of PM relies on CT scans, cultures, PCR tests, and histology. The reversed halo sign is an early, but very suggestive, sign of PM in neutropenic patients. Recently, the serum PCR test showed a very encouraging performance for the diagnosis and follow-up of mucormycosis. Liposomal amphotericin B is the drug of choice for first-line therapy, together with correction of underlying disease and surgery when feasible. After a stable or partial response, the step-down treatment includes oral isavuconazole or posaconazole delayed release tablets until a complete response is achieved. Secondary prophylaxis should be discussed when there is any risk of relapse, such as the persistence of neutropenia or the prolonged use of high-dose immunosuppressive therapy. Despite these novelties, the mortality rate from PM remains higher than 50%. Therefore, future research must define the place for combination therapy and adjunctive treatments, while the development of new treatments is necessary.

Mucormycosis threats: A systemic review

During the catastrophic wave of Coronavirus disease 2019, health agencies started to report an infrequent but lethal mucormycosis or black fungal infection. Primarily, it causes sinusitis by affecting nasal, oral, lung, brain, ocular, and other body tissues. It becomes more fatal, especially in diabetic, cancer, and immune-compromised patients. Before 2020, the prevalence of mucormycosis was very rare but it has rapidly emerged globally from late 2020 to mid-2021. Recently, the mucormycosis got worse and epidemic with more than 30,000 cases reported across India. The etiology of infection can be diagnosed by molecular, serological, microscopic, and clinical methods. However, early diagnosis of this ailment is still a challenging task due to no standalone diagnostic tool available along with clinical manifestations of the ailment resembling other fungal diseases. The treatment of mucormycosis is also challenging and frequently requires long-term treatment. Amphotericin B was found to be an effective antifungal for preventing mucormycosis but it failed if infection disseminated to necrotizing tissues or adjacent organs. Removal of infected tissue/organ by surgery is an alternative treatment to control mucormycosis. In addition, reversal of underlying predisposing conditions based on therapy is also in practice for its prevention. This review highlights different aspects of mucormycosis such as pathogenesis, diagnosis, treatment, and their challenges and so on. We also emphasized the epidemiological shift during the recent outbreak and its influence on the different regions of India.

Black Fungus and beyond: COVID-19 associated infections

Globally, many hospitalized COVID-19 patients can experience an unexpected acute change in status, prompting rapid and expert clinical assessment. Superimposed infections can be a significant cause of clinical and radiologic deviations in this patient population, further worsening clinical outcome and muddling the differential diagnosis. As thrombotic, inflammatory, and medication-induced complications can also trigger an acute change in COVID-19 patient status, imaging early and often plays a vital role in distinguishing the cause of patient decline and monitoring patient outcome. While the common radiologic findings of COVID-19 infection are now widely reported, little is known about the clinical manifestations and imaging findings of superimposed infection. By discussing case studies of patients who developed bacterial, fungal, parasitic, and viral co-infections and identifying the most frequently reported imaging findings of superimposed infections, physicians will be more familiar with common infectious presentations and initiate a directed workup sooner. Ultimately, any abrupt changes in the expected COVID-19 imaging presentation, such as the presence of new consolidations or cavitation, should prompt further workup to exclude superimposed opportunistic infection.

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.

Spectrum of Mucormycosis Before and During COVID-19: Epidemiology, Diagnosis, and Current Therapeutic Interventions

Purpose of Review

More than half a billion people have been infected and 6.2 million killed by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) since the start of the pandemic in 2019. Systemic glucocorticoids are a double-edged sword, on the one hand, life-saving in treating COVID-19 complications while on the other hand, potentially leading to life-and-limb-threatening opportunistic fungal infections. Mucormycosis (MM) is caused by the mucormycetes family. Although rare, it is characterized by high mortality and significant morbidity. The gross similarities observed with other fungal infections which respond to different treatment regimens have made it all the more imperative to quickly and sensitively diagnose and treat MM. This review discusses the epidemiology of MM before and during the COVID-19 pandemic, associated risk factors, COVID-19-associated MM, diagnosis, and current therapeutic interventions.

Recent Findings

There has been a widespread and worrisome trend of rising in cases of MM, worldwide, but more so in the Indian subcontinent, where it is nicknamed the “black fungus.” This upsurge has picked up the pace ever since the start of the COVID-19 pandemic. Necrosis is secondary to the angio-invasive and pro-thrombotic nature of the mold resulting in extensive lesions presenting mostly as rhino-orbital MM (ROM) and rhino-orbito-cerebral MM (ROCM). Infection is mostly observed in subjects with underlying risk factors such as uncontrolled diabetes, those receiving hematopoietic stem cell transplant, and/or on corticosteroid or immunosuppressive therapy, although it is widely suspected that other factors such as iron and zinc may play a role in the pathogenesis of MM. The “One world one guideline” strategy advocates both prophylactic anti-fungal therapy along with aggressive, prompt, and individualized treatment with anti-fungal drugs such as amphotericin B in addition to vigorous surgical intervention. High-risk groups need particularly rapid diagnosis although empirical anti-fungal therapy may not be delayed. Speeding diagnostic turnaround times are essential to institute early therapy, and there is much scope for newer modalities such as PCR, matrix-assisted laser desorption ionization-time of flight mass spectrometry, and whole-genome sequencing in such endeavors. The results of strict monitoring of blood glucose levels along with rational and limited use of steroids and immunomodulatory drugs have proven to be a significant preventive measure.

Summary

The significant rise in cases of MM worldwide has necessitated viewing each case with a strong index of suspicion. Adoption of rapid diagnostics, early antifungal therapy, and prompt surgical interventions are essential, while high-risk groups need particular focused care which may include prophylactic anti-fungal therapy, limited steroid use, and meticulous control of the underlying disease. Developing quicker and more sensitive diagnostic modalities has great potential to improve the detection and management of MM.

Clinical Manifestations of Pulmonary Mucormycosis in Recipients of Allogeneic Hematopoietic Stem Cell Transplantation: A 21-Case Series Report and Literature Review

Introduction

Mucormycosis is a rare, invasive disease caused by opportunistic pathogens related to the Mucorales order with high fatality rates in immunocompromised hosts, especially in recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Diagnosis and treatment of pulmonary mucormycosis in recipients of allo-HSCT remains challenging.

Purpose

The aim of this study is to summarize and analyze the clinical features of pulmonary mucormycosis in recipients of allo-HSCT to explore further clinical research directions for this rare fungal infection in the particular populations.

Methods

We retrospectively reviewed pulmonary mucormycosis in patients who received allo-HSCT in our hospital from January 2010 to December 2020. A total of 21 patients fulfilled the diagnostic criteria for pulmonary mucormycosis according to the European Organization for Research and Treatment of Cancer and Mycoses Study Group (EORTC/MSG) criteria. Demographic and clinical data, mycological and histopathological records, and treatment and prognosis data were collected. Clinical variables were compared between survivors and nonsurvivors. The survival days of patients with and without graft-versus-host disease (GVHD) and hemoptysis were compared separately.

Results

Most of the recipients of allo-HSCT were male patients with a mean age of 43 years. Acute myeloid leukemia (AML) was the most common primary hematologic malignancy. Extrapulmonary involvement accounted for 28.6%, of the cases, including central nervous system (n = 5) and skin and soft tissue (n = 1). The median time to infection was 96 days after allo-HSCT. Clinical presentations were nonspecific, including fever (76.2%) and cough (85.7%), as well as dyspnea (19.0%), chest pain (38.1%), and hemoptysis (61.9%). Ground-glass infiltrates (95.0%) and nodules/masses (80%) were the most common radiographic patterns on chest CT. The most common pathogen was Rhizopus (63.2%), and breakthrough infection accounted for 90.5%. Fifteen of the patients died within one year, and the median time from diagnosis to death was 47 days.

Conclusion

Mucormycosis is a fatal infection disease. Opportunistic infections in recipients of allo-HSCT are mainly breakthrough infections and may have a seasonal distribution (summer and autumn) and more cases of death in autumn. The marked reversed halo sign can be seen both in the initial stage of infection and after antifungal treatment. In our case series, patients with pulmonary mucormycosis with extrapulmonary involvement 100% died within one year. There are more patients with GVHD before infection and hemoptysis in nonsurvivors than survivors within 100 days. Patients with GVHD before infection and hemoptysis have a shorter survival time than those without.

Outcomes after lung resection in renal transplant patients with pulmonary mucormycosis

Pulmonary mucormycosis has been associated with high mortality (reported up to 100%) in renal transplant recipients. This was a retrospective analysis of renal transplant patients with pulmonary mucormycosis between April 2014 - March 2020, who underwent surgical resection of the affected lung along with liposomal amphotericin therapy. Patients with lower respiratory illness features underwent chest X-ray, high-resolution computed tomography of the chest, and those with suspicious findings underwent analysis of bronchioloalveolar fluid and transbronchial lung biopsy. Patients with histological or microbiological evidence of mucormycosis were started on liposomal Amphotericin B. Tacrolimus and mycophenolate mofetil were stopped at the time of diagnosis. Patients were taken up for surgical resection of the affected part of the lung. Ten patients underwent combined management, while five patients were managed medically. At last follow up, seven out of ten patients (70%) who underwent combined management and two of the five patients (40%) who were managed medically, had a mean survival of 28.86 months (sd = 15.71, median = 25) and 14.17 months (sd = 12.21, median = 18), respectively, post-diagnosis of pulmonary mucormycosis. Surgical resection combined with antifungals in the perioperative period and decreased immunosuppression may improve the outcomes in renal transplant patients with pulmonary mucormycosis. This article is protected by copyright. All rights reserved.

The Value of Nasal and Oral Clinical Examination in Febrile Neutropenic Patients for Initiating Antifungal Therapy as a Preemptive Method

BACKGROUND

Invasive fungal infections (IFIs) are complications that lead to mortality and morbidity in hematologic malignancies. The time of starting antifungal therapy is vital. Preemptive antifungal therapy has appeared recently as a new policy for the management of IFIs based on noninvasive ways in neutropenic patients.

METHODS

We enrolled leukemia patients with neutropenia after chemotherapy in Imam Khomeini Hospital Complex, Tehran, Iran. Patients who entered the neutropenic phase were divided into two categories (empirical and preemptive) for receiving antifungal agents. The patients were clinically examined in the preemptive group every day to find IFIs. As soon as clinical evidence of IFIs was observed, antifungal was prescribed. The empirical group patients received antifungals based on the ward protocol. Based on the data in each group, the diagnostic and therapeutic results of cases are followed-up to 3 months. To compare percentages between the two groups, the chi-squared test was used. And to compare two means between the two groups, the independent t-test was used. All the statistical analyses were done in the Statistical Package for the Social Sciences (SPSS) version 24 software (IBM Corporation, Armonk, New York, USA).

RESULTS

We assessed 132 leukemic patients with inclusion and exclusion criteria. Eventually, 80 patients were enrolled. The mean age was 35.52 years. Demographics data and distribution of leukemia type show no significant differences between the two groups. Despite a higher percentage of IFIs discovered in the preemptive group than the empirical group (25 vs. 18.75%, respectively), but data show no significant differences. The average days of IFIs diagnosis since the beginning of neutropenia in the empirical group were 9.5 days while in the preemptive group, the average days were 5.4 days (p < 0.05). Totally, there were 15 patients with a proven IFI in each group (40% in the empirical group and 60% in the preemptive group). Results significantly show an increase in surgical sinus debridement in the empirical groups (83.3%) vs. the preemptive groups (55.5%), (p < 0.05). The mortality rate differed significantly among the two groups; it was 7.5% in the preemptive group and 25% in the empirical group (p < 0.05).

CONCLUSION

Daily oral and nasal cavities examination to find the symptoms of IFIs and then start preemptive antifungal agents may be able to lead to accurate diagnosis, earlier treatment, and decreasing sinus surgery debridement in leukemia patients with neutropenia.

Storm of a rare opportunistic life threatening mucormycosis among post COVID-19 patients: A tale of two pathogens

Mucormycosis is a rare but life-threatening opportunistic fungal infection caused by a group of molds that belong to Zygomycetes of the order Mucorales. These fungi are found in the environment such as soil, decaying vegetation, and organic matters. Sporangiospores present in the environment enter the human body through inhalation or direct skin inoculation by trauma or ingestion and result in pulmonary, cutaneous, and gastrointestinal mucormycosis, respectively, in immunocompromised hosts. Patients with uncontrolled diabetes, hematological malignancies, high-dose glucocorticoid therapy, iron overload, and organ transplantation are at high risk of acquiring mucormycosis. The second wave of severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2] affected India severely with the highest number of cases and deaths compared to all other countries. Additionally, the country was affected by emergence of rare but life-threatening mucormycosis. Currently, many coronavirus disease 2019 patients with underlying risk factors such as uncontrolled diabetes, high-dose steroid therapy, and exposure to mechanical ventilation have developed mucormycosis. Inhalation is the most common mode of transmission that results in colonization of sporangiospores in the nose. In immunocompromised host, sporangiospores germinate, and subsequently form hyphae. These hyphae invade into tissues, and produce tissue infarction, necrosis, and thrombosis. Angioinvasion causes hematogenous dissemination to many organs, predominantly to brain, that result in rhino-orbital-cerebral mucormycosis. Clinical characteristics, radio imaging, fungal culture, histopathology, and molecular techniques are the key diagnostic methods. Surgical intervention and aggressive antifungal therapy are the main management strategies. Amphotericin B is the drug of choice for treatment of mucormycosis, whereas posaconazole or isavuconazole is used for step-down therapy and salvage therapy.

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.

Characteristics of Mucormycosis in Hematological Patients and a Death Prediction Model

Mucormycosis is an angioinvasive fungal infection, associated with high mortality. The aim of our study was to explore the high-risk factors and predict the death of hematological disease complicated with mucormycosis. We retrospectively analyzed clinical data of 31 patients with hematological disease complicated with mucormycosis, adopted random forest to establish the death prediction model, and validated the model in another 15 patients. The median age of the 31 cases was 46 (28–51) years, male to female ratio 1.38:1, and 90-day mortality rate 54.8%. The most common underlying disease was acute myeloid leukemia (58.1%). The main clinical symptoms were fever (100%), cough (87.1%), sputum (80.6%), chest pain (61.3%), and hemoptysis (19.4%). Reversed halo sign (83.9%) was the most common computed tomography sign. A total of 48.4% of patients also had aspergillus or bacterial infections. Discriminative models were constructed by random forest with 17 non-survivors and 14 survivors. Procalcitonin, the duration of intravenous administration of amphotericin B or amphotericin B liposomes, and neutropenia at death or 90 days of survival were the leading risk factors for poor prognosis, with area under the curve of 0.975 (95% CI 0.934–1). We chose 0.6775 as death prediction threshold (with 82.3% sensitivity and 100% specificity) and validated the model successfully in another 15 patients. Chest pain and reversed halo sign are specific clinical and image signs of hematological disease complicated with mucormycosis. Neutropenia, elevated procalcitonin, and insufficient use time of amphotericin B or amphotericin B liposomes are risk factors for death.

Newer Horizon of Mesenchymal Stem Cell-Based Therapy in the Management of SARS-CoV-2-Associated Mucormycosis: A Safe Hope for Future Medicine

SARS-CoV-2-infected patients are reported to show immunocompromised behavior that gives rise to a wide variety of complications due to impaired innate immune response, cytokine storm, and thrombo-inflammation. Prolonged use of steroids, diabetes mellitus, and diabetic ketoacidosis (DKA) are some of the factors responsible for the growth of Mucorales in such immunocompromised patients and, thus, can lead to a life-threatening condition referred to as mucormycosis. Therefore, an early diagnosis and cell-based management cosis is the need of the hour to help affected patients overcome this severe condition. In addition, extended exposure to antifungal drugs/therapeutics is found to initiate hormonal and neurological complications. More recently, mesenchymal stem cells (MSCs) have been used to exhibit immunomodulatory function and proven to be beneficial in a clinical cell-based regenerative approach. The immunomodulation ability of MSCs in mucormycosis patient boosts the immunity by the release of chemotactic proteins. MSC-based therapy in mucormycosis along with the combination of short-term antifungal drugs can be utilized as a prospective approach for mucormycosis treatment with promising outcomes. However, preclinical and in mucormyIn mucormycosis, the hyphae of clinical trials are needed to establish the precise mechanism of MSCs in mucormycosis treatment.

Future challenges and chances in the diagnosis and management of invasive mould infections in cancer patients

Diagnosis, treatment, and management of invasive mould infections (IMI) are challenged by several risk factors, including local epidemiological characteristics, the emergence of fungal resistance and the innate resistance of emerging pathogens, the use of new immunosuppressants, as well as off-target effects of new oncological drugs. The presence of specific host genetic variants and the patient's immune system status may also influence the establishment of an IMI and the outcome of its therapy. Immunological components can thus be expected to play a pivotal role not only in the risk assessment and diagnosis, but also in the treatment of IMI. Cytokines could improve the reliability of an invasive aspergillosis diagnosis by serving as biomarkers as do serological and molecular assays, since they can be easily measured, and the turnaround time is short. The use of immunological markers in the assessment of treatment response could be helpful to reduce overtreatment in high risk patients and allow prompt escalation of antifungal treatment. Mould-active prophylaxis could be better targeted to individual host needs, leading to a targeted prophylaxis in patients with known immunological profiles associated with high susceptibility for IMI, in particular invasive aspergillosis. The alteration of cellular antifungal immune response through oncological drugs and immunosuppressants heavily influences the outcome and may be even more important than the choice of the antifungal treatment. There is a need for the development of new antifungal strategies, including individualized approaches for prevention and treatment of IMI that consider genetic traits of the patients.

Lay Abstract

Anticancer and immunosuppressive drugs may alter the ability of the immune system to fight invasive mould infections and may be more important than the choice of the antifungal treatment. Individualized approaches for prevention and treatment of invasive mold infections are needed.

Radiological CT Patterns and Distribution of Invasive Pulmonary Aspergillus, Non-Aspergillus, Cryptococcus and Pneumocystis Jirovecii Mold Infections - A Multicenter Study

PURPOSE

 Clinical signs and symptoms related to invasive fungal disease are nonspecific and need to be followed up by appropriate diagnostic procedures. The goal of this study was to analyze CT imaging patterns in invasive fungal infections and their correlation with the immune status and clinical outcome.

MATERIALS AND METHODS

 We performed a retrospective multicenter study including 85 consecutive patients with invasive pulmonary fungal infection (2011-2014). Lung patterns on computed tomography (CT) scans were classified according to the Fleischner Society glossary. The patients were grouped according to immune status (neutropenia, steroid therapy, organ transplant recipient, and other cause) and outcome (positive outcome, progressive disease, and death). The Chi square test or Fisher exact test was used. Bonferroni correction was applied.

RESULTS

 The total number of patients with invasive Aspergillus and non-Aspergillus infection (IANA), Pneumocystis jirovecii pneumonia (PCP), and Cryptococcus (CRY) was 60, 22, and 3, respectively. Patients with IANA demonstrated significantly more nodules (93 % vs. 59 %, p = 0.001), significantly fewer ground glass opacities (58 % vs. 96 %, p = 0.005), and significantly fewer positive lymph nodes (5 % vs. 41 %, p < 0.001) than patients with PCP. All patients with PCP and CRY had a favorable outcome. Patients with IANA and an adverse outcome demonstrated significantly more nodules with halo sign than patients with IANA and a favorable outcome (42.5 % vs. 15.9 %, p < 0.0001). Interestingly, patients with IANA and a favorable outcome had a higher prevalence of pulmonary infarction than patients with an adverse outcome (8 % vs. 1 %, p = 0.047). Patients with neutropenia showed significantly more consolidations (66 %) than organ transplant recipients (27 %, p = 0.045).

CONCLUSION

 Patients with IANA showed a higher prevalence of nodules and a lower prevalence of ground glass opacities than patients with PCP. In patients with IANA, nodules with halo sign were associated with an adverse outcome. Patients with neutropenia showed generally more consolidations, but the consolidations were not associated with an adverse outcome.

KEY POINTS

  · Nodules, ground glass opacities, and consolidations are common CT findings in all invasive pulmonary fungal infections.. · There is no pattern that is unique for one specific pathogen, although nodules are more predominant in IANA and Cryptococcus, and ground glass opacities are more predominant in PCP patients.. · Immune status had an impact on CT findings in fungal pneumonia with less consolidation in patients after organ transplantation compared to patients with neutropenia.. · Nodules with a halo sign are associated with a worse outcome..

CITATION FORMAT

· Obmann VC, Bickel F, Hosek N et al. Radiological CT Patterns and Distribution of Invasive Pulmonary Aspergillus, Non-Aspergillus, Cryptococcus and Pneumocystis Jirovecii Mold Infections - A Multicenter Study. Fortschr Röntgenstr 2021; DOI: 10.1055/a-1482-8336.

Guidance on Imaging for Invasive Pulmonary Aspergillosis and Mucormycosis: From the Imaging Working Group for the Revision and Update of the Consensus Definitions of Fungal Disease from the EORTC/MSGERC

BACKGROUND

Clinical imaging in suspected invasive fungal disease (IFD) has a significant role in early detection of disease and helps direct further testing and treatment. Revised definitions of IFD from the EORTC/MSGERC were recently published and provide clarity on the role of imaging for the definition of IFD. Here, we provide evidence to support these revised diagnostic guidelines.

METHODS

We reviewed data on imaging modalities and techniques used to characterize IFDs.

RESULTS

Volumetric high-resolution computed tomography (CT) is the method of choice for lung imaging. Although no CT radiologic pattern is pathognomonic of IFD, the halo sign, in the appropriate clinical setting, is highly suggestive of invasive pulmonary aspergillosis (IPA) and associated with specific stages of the disease. The ACS is not specific for IFD and occurs in the later stages of infection. By contrast, the reversed halo sign and the hypodense sign are typical of pulmonary mucormycosis but occur less frequently. In noncancer populations, both invasive pulmonary aspergillosis and mucormycosis are associated with "atypical" nonnodular presentations, including consolidation and ground-glass opacities.

CONCLUSIONS

A uniform definition of IFD could improve the quality of clinical studies and aid in differentiating IFD from other pathology in clinical practice. Radiologic assessment of the lung is an important component of the diagnostic work-up and management of IFD. Periodic review of imaging studies that characterize findings in patients with IFD will inform future diagnostic guidelines.

Johnson E, Littlechild J, Winlove CP, Vollmer F, Gow NAR. Biosensors and Diagnostics for Fungal Detection

Early detection is critical to the successful treatment of life-threatening infections caused by fungal pathogens, as late diagnosis of systemic infection almost always equates with a poor prognosis. The field of fungal diagnostics has some tests that are relatively simple, rapid to perform and are potentially suitable at the point of care. However, there are also more complex high-technology methodologies that offer new opportunities regarding the scale and precision of fungal diagnosis, but may be more limited in their portability and affordability. Future developments in this field are increasingly incorporating new technologies provided by the use of new format biosensors. This overview provides a critical review of current fungal diagnostics and the development of new biophysical technologies that are being applied for selective new sensitive fungal biosensors to augment traditional diagnostic methodologies.

Epidemiology and Diagnosis of Mucormycosis: An Update

Mucormycosis is an angioinvasive fungal infection, due to fungi of the order Mucorales. Its incidence cannot be measured exactly, since there are few population-based studies, but multiple studies have shown that it is increasing. The prevalence of mucormycosis in India is about 80 times the prevalence in developed countries, being approximately 0.14 cases per 1000 population. Diabetes mellitus is the main underlying disease globally, especially in low and middle-income countries. In developed countries the most common underlying diseases are hematological malignancies and transplantation. Τhe epidemiology of mucormycosis is evolving as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and as the modern diagnostic tools lead to the identification of previously uncommon genera/species such as Apophysomyces or Saksenaea complex. In addition, new risk factors are reported from Asia, including post-pulmonary tuberculosis and chronic kidney disease. New emerging species include Rhizopus homothallicus, Thamnostylum lucknowense, Mucor irregularis and Saksenaea erythrospora. Diagnosis of mucormycosis remains challenging. Clinical approach to diagnosis has a low sensitivity and specificity, it helps however in raising suspicion and prompting the initiation of laboratory testing. Histopathology, direct examination and culture remain essential tools, although the molecular methods are improving. The internal transcribed spacer (ITS) region is the most widely sequenced DNA region for fungi and it is recommended as a first-line method for species identification of Mucorales. New molecular platforms are being investigated and new fungal genetic targets are being explored. Molecular-based methods have gained acceptance for confirmation of the infection when applied on tissues. Methods on the detection of Mucorales DNA in blood have shown promising results for earlier and rapid diagnosis and could be used as screening tests in high-risk patients, but have to be validated in clinical studies. More, much needed, rapid methods that do not require invasive procedures, such as serology-based point-of-care, or metabolomics-based breath tests, are being developed and hopefully will be evaluated in the near future.

Pulmonary mucormycosis following autologous hematopoietic stem cell transplantation for rapidly progressive diffuse cutaneous systemic sclerosis: A case report

RATIONALE

The use of autologous hematopoietic stem cell transplantation (AHSCT) for autoimmune diseases has become the first indication for transplant in nonmalignant disease. Mucormycosis is a rare invasive infection with increasing incidence in patients treated with AHSCT. We report the first case of pulmonary mucormycosis following AHSCT for systemic sclerosis (SSc).

PATIENT CONCERNS

A 24-year-old woman with rapidly progressive diffuse cutaneous SSc presented with an acute respiratory distress syndrome 6 days after AHSCT.

DIAGNOSES

The results of clinical and computed tomography scan were consistent with pulmonary mucormycosis and the diagnosis was confirmed by a positive Mucorales Polymerase Chain Reaction on a peripheral blood sample.

INTERVENTIONS AND OUTCOMES

Early antifungal therapy by intravenous amphotericin B provided rapid improvement within 4 days and sustained recovery after 2 years of follow-up.

LESSONS

With the progressively increasing use of AHSCT and other stem cell therapy for treatment of severe SSc and other autoimmune diseases, the potential onset of rare post-transplant fungal infections, such as mucormycosis, requires careful patient monitoring and better awareness of early initiation of adequate therapy.

Developments in identifying and managing mucormycosis in hematologic cancer patients

INTRODUCTION

Mucormycoses represent a rare but very aggressive class of mold infections occurring in patients with hematological malignancies (HMs). In the past, patients at high risk of invasive mucomycosis (IM) were those affected by acute myeloid leukemia but over the last ten years the prophylaxis with a very effective mold-active drug, such as posaconazole, has completely modified the epidemiology. In fact, IM is now observed more frequently in patients with lymphoproliferative disorders who do not receive antifungal prophylaxis.

AREAS COVERED

The attention was focused on the epidemiology, diagnosis, prophylaxis and treatment of IM in HMs. Authors excluded pediatric patients considering the different epidemiology and differences in treatment given the limitation of the use of azoles in the pediatric field. A systematic literature review was performed using PubMed database listings between February 2014 and February 2020 using the following MeSH terms: leukemia, hematological malignancies, stem cell transplantation, mucormycosis, molds, prophilaxis, treatment.

EXPERT OPINION

The epidemiology of mucormycosis in HMs is changing in the last years. The availability of drugs more effective than in the past against this infection has reduced the mortality; however, a timely diagnosis remains a relevant problem potentially influencing the outcome of hematologic patients with IM.

Diagnosis and treatment of invasive fungal infections: looking ahead

Improved standards of care depend on the development of new laboratory diagnostic and imaging procedures and the development of new antifungal compounds. Immunochromatography technologies have led to the development of lateral flow devices for the diagnosis of cryptococcal meningitis and invasive aspergillosis (IA). Similar devices are being developed for the detection of histoplasmosis that meet the requirements for speed (∼15 min assay time) and ease of use for point-of-care diagnostics. The evolution of molecular tools for the detection of fungal pathogens has been slow but the introduction of new nucleic acid amplification techniques appears to be helpful, for example T2Candida. An Aspergillus proximity ligation assay has been developed for a rapid near-patient bedside diagnosis of IA. CT remains the cornerstone for radiological diagnosis of invasive pulmonary fungal infections. MRI of the lungs may be performed to avoid radiation exposure. MRI with T2-weighted turbo-spin-echo sequences exhibits sensitivity and specificity approaching that of CT for the diagnosis of invasive pulmonary aspergillosis. The final part of this review looks at new approaches to drug discovery that have yielded new classes with novel mechanisms of action. There are currently two new classes of antifungal drugs in Phase 2 study for systemic invasive fungal disease and one in Phase 1. These new antifungal drugs show promise in meeting unmet needs with oral and intravenous formulations available and some with decreased potential for drug-drug interactions. Novel mechanisms of action mean these agents are not susceptible to the common resistance mechanisms seen in Candida or Aspergillus. Modification of existing antifungal susceptibility testing techniques may be required to incorporate these new compounds.

Pulmonary Mucormycosis: Risk Factors, Radiologic Findings, and Pathologic Correlation

Pulmonary mucormycosis (PM) is an uncommon fungal infection most often seen in immunocompromised patients. The fungus grows on decaying food, soil, and animal excrement. Patients usually become infected by inhalation of spores. The most common risk factors include diabetes mellitus, hematologic malignancy, and solid organ or stem cell transplant. PM can have a nonspecific appearance at imaging. For example, early imaging may show peribronchial ground-glass opacity. Later, the disease progresses to consolidation, nodules, or masses. Because patients are usually immunocompromised, the differential diagnosis often includes invasive pulmonary aspergillosis (IPA). Various radiologic findings suggestive of PM have been identified to help differentiate it from IPA. For example, the reverse halo sign is more closely associated with PM than with IPA. The reverse halo sign is an area of ground-glass opacity surrounded by a rim of consolidation. In addition, the presence of pleural effusions and more than 10 nodules is more suggestive of PM than it is of IPA. PM can progress rapidly in neutropenic patients. Identification of the hyphae in tissue by using endobronchial or percutaneous sampling can allow differentiation from IPA and help confirm the diagnosis of mucormycosis. Because of the high mortality rate associated with PM, early identification of the disease is critical for an improved likelihood of survival. A multimodality treatment approach with antifungal agents and surgical débridement has been shown to improve outcomes. The authors review the risk factors for PM, describe its imaging appearance and disease process, and describe the treatment of the disease. ^©RSNA, 2020.

Chest imaging using signs, symbols, and naturalistic images: a practical guide for radiologists and non-radiologists

Several imaging findings of thoracic diseases have been referred-on chest radiographs or CT scans-to signs, symbols, or naturalistic images. Most of these imaging findings include the air bronchogram sign, the air crescent sign, the arcade-like sign, the atoll sign, the cheerios sign, the crazy paving appearance, the comet-tail sign, the darkus bronchus sign, the doughnut sign, the pattern of eggshell calcifications, the feeding vessel sign, the finger-in-gloove sign, the galaxy sign, the ginkgo leaf sign, the Golden-S sign, the halo sign, the headcheese sign, the honeycombing appearance, the interface sign, the knuckle sign, the monod sign, the mosaic attenuation, the Oreo-cookie sign, the polo-mint sign, the presence of popcorn calcifications, the positive bronchus sign, the railway track appearance, the scimitar sign, the signet ring sign, the snowstorm sign, the sunburst sign, the tree-in-bud distribution, and the tram truck line appearance. These associations are very helpful for radiologists and non-radiologists and increase learning and assimilation of concepts.Therefore, the aim of this pictorial review is to highlight the main thoracic imaging findings that may be associated with signs, symbols, or naturalistic images: an "iconographic" glossary of terms used for thoracic imaging is reproduced-placing side by side radiological features and naturalistic figures, symbols, and schematic drawings.

Clinical features of pulmonary mucormycosis in patients with different immune status

Background

Pulmonary mucormycosis (PM) is a relatively rare but often fatal and rapidly progressive disease. Most studies of PM are case reports or case series with limited numbers of patients, and focus on immunocompromised patients. We investigated the clinical manifestations, imaging features, treatment, and outcomes of patients with PM with a focus on the difference in clinical manifestations between patients with different immune status.

Methods

Clinical records, laboratory results, and computed tomography scans of 24 patients with proven or probable PM from January 2005 to December 2018 in Peking Union Medical College Hospital were retrospectively analyzed.

Results

Ten female and 14 male patients were included (median age, 43.5 years; range, 13-64 years). Common presenting symptoms were fever (70.8%), cough (70.8%), sputum production (54.2%), and hemoptysis (41.7%). Radiological findings included consolidation (83.3%), ground-glass opacities (58.3%), nodules (50.0%), masses (37.5%), cavities (33.3%), mediastinal lymphadenopathy (29.2%), and halo sign (12.5%); one patient had a reversed halo sign. Seven patients (29.2%) had no obvious predisposing risk factors, and 17 (70.8%) had underlying diseases including diabetes, hematological malignancy, and use of immunosuppressants. Compared with immunocompromised patients, immunocompetent patients with PM were younger {23 [13-46] vs. 48 [17-64] years, P=0.023}, comprised a higher proportion of men (100.0% vs. 41.2%, P=0.019), had a longer disease course {34 [8-47] vs. 9 [2-102] weeks, P=0.033}, had a higher eosinophil count [0.66 (0.07-2.00) ×10⁹/L vs. 0.04 (0.00-0.23) ×10⁹/L, P=0.001], and had a lower erythrocyte sedimentation rate {12 [1-88] vs. 74 [9-140] mm/h, P=0.032}.

Conclusions

PM can occur in heterogeneous patients with different immune status, and the clinical phenotype differs between immunocompetent and immunocompromised patients. Because of the lack of specific clinic and imaging manifestations, aggressive performance of invasive procedures to obtain histopathological and microbial evidence is crucial for a definitive diagnosis.

Global guideline for the diagnosis and management of mucormycosis: an initiative of the European Confederation of Medical Mycology in cooperation with the Mycoses Study Group Education and Research Consortium

Mucormycosis is a difficult to diagnose rare disease with high morbidity and mortality. Diagnosis is often delayed, and disease tends to progress rapidly. Urgent surgical and medical intervention is lifesaving. Guidance on the complex multidisciplinary management has potential to improve prognosis, but approaches differ between health-care settings. From January, 2018, authors from 33 countries in all United Nations regions analysed the published evidence on mucormycosis management and provided consensus recommendations addressing differences between the regions of the world as part of the "One World One Guideline" initiative of the European Confederation of Medical Mycology (ECMM). Diagnostic management does not differ greatly between world regions. Upon suspicion of mucormycosis appropriate imaging is strongly recommended to document extent of disease and is followed by strongly recommended surgical intervention. First-line treatment with high-dose liposomal amphotericin B is strongly recommended, while intravenous isavuconazole and intravenous or delayed release tablet posaconazole are recommended with moderate strength. Both triazoles are strongly recommended salvage treatments. Amphotericin B deoxycholate is recommended against, because of substantial toxicity, but may be the only option in resource limited settings. Management of mucormycosis depends on recognising disease patterns and on early diagnosis. Limited availability of contemporary treatments burdens patients in low and middle income settings. Areas of uncertainty were identified and future research directions specified.

Detection of the 'Big Five' mold killers of humans: Aspergillus, Fusarium, Lomentospora, Scedosporium and Mucormycetes

Fungi are an important but frequently overlooked cause of morbidity and mortality in humans. Life-threatening fungal infections mainly occur in immunocompromised patients, and are typically caused by environmental opportunists that take advantage of a weakened immune system. The filamentous fungus Aspergillus fumigatus is the most important and well-documented mold pathogen of humans, causing a number of complex respiratory diseases, including invasive pulmonary aspergillosis, an often fatal disease in patients with acute leukemia or in immunosuppressed bone marrow or solid organ transplant recipients. However, non-Aspergillus molds are increasingly reported as agents of disseminated diseases, with Fusarium, Scedosporium, Lomentospora and mucormycete species now firmly established as pathogens of immunosuppressed and immunocompetent individuals. Despite well-documented risk factors for invasive fungal diseases, and increased awareness of the risk factors for life-threatening infections, the number of deaths attributable to molds is likely to be severely underestimated driven, to a large extent, by the lack of readily accessible, cheap, and accurate tests that allow detection and differentiation of infecting species. Early diagnosis is critical to patient survival but, unlike Aspergillus diseases, where a number of CE-marked or FDA-approved biomarker tests are now available for clinical diagnosis, similar tests for fusariosis, scedosporiosis and mucormycosis remain experimental, with detection reliant on insensitive and slow culture of pathogens from invasive bronchoalveolar lavage fluid, tissue biopsy, or from blood. This review examines the ecology, epidemiology, and contemporary methods of detection of these mold pathogens, and the obstacles to diagnostic test development and translation of novel biomarkers to the clinical setting.

Beyond biomarkers: How enhanced CT imaging can improve the diagnostic-driven management of invasive mould disease

CT imaging remains an essential diagnostic test for identification, staging and management of invasive mould infection (IMI) in patients with hematological malignancies. Yet the limited specificity of standard CT imaging can drive excessive antifungal use in patients, especially when more definitive diagnosis cannot be established through microbiology or invasive diagnostic procedures. CT pulmonary angiography (CTPA) is a complimentary, non-invasive approach to standard CT that allows for direct visualization of pulmonary arteries inside infiltrates for signs of angioinvasion, vessel destruction and vessel occlusion. Experience from several centers that are using CTPA as part of a standard diagnostic protocol for IMI suggests that a positive vessel occlusion sign (VOS) is the most sensitive and a specific sign of IMI in both neutropenic and non-neutropenic patients. CTPA is particularly useful in patients who develop suspected breakthrough IMI during antifungal prophylaxis because, unlike serum and/or BAL galactomannan and polymerase chain reaction (PCR) testing, the sensitivity is not reduced by antifungal therapy. A negative VOS may also largely rule-out the presence of IMI, supporting earlier discontinuation of empirical therapy. Future imaging protocols for IMI in patients with hematological malignancies will likely replace standard chest X-rays in favor of early low radiation dose CT exams for screening, with characterization of the lesions by CTPA and routine follow-up using functional/metabolic imaging such as 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (FDG-PET/CT) to assess treatment response. Hence, enhanced CT imaging techniques can improve the diagnostic-driven management of IMI management in high-risk patients with hematological malignancies.