Prospective antifungal therapy (PATH) alliance®: focus on mucormycosis

Diagnostic limitations and challenges in current clinical guidelines and potential application of metagenomic sequencing to manage pulmonary invasive fungal infections in patients with haematological malignancies

BACKGROUND

Pulmonary invasive fungal infections (pIFI) disproportionately affect patients with haematological malignancies (HM). Establishing a rapid and accurate diagnosis of pIFI is challenging. Multiple guidelines recommend diagnostic testing of invasive fungal infections but lack consensus and may contribute to inconsistent diagnostic approaches.

OBJECTIVE

To identify key diagnostic challenges and review metagenomic sequencing data.

SOURCES

PubMed, professional consortium, and scientific society websites search to identify relevant, published, evidence-based clinical guidelines within the past 5 years. PubMed searchs for papers describing clinically relevant novel diagnostic technologies.

CONTENT

Current guidelines for patients with HM and suspected pIFI recommend chest computed tomography imaging and specimen testing with microscopic examination (including calcofluor white stain, histopathology, cytopathology, etc.), Aspergillus galactomannan, β-D-glucan, PCR, and culture, each with certain limitations. Emerging real-world data support the adjunctive use of metagenomic sequencing-based tests for the timely diagnosis of pIFI.

IMPLICATIONS

High-quality evidence from robust clinical trials is needed to determine whether guidelines should be updated to include novel diagnostic technologies. Trials should ask whether the combination of powerful novel diagnostics, such as pathogen-agnostic metagenomic sequencing technologies in conjunction with conventional testing can optimize the diagnostic yield for all potential pIFI pathogens that impact the health of patients with HM.

Pediatric mucormycosis associated with COVID-19: A systematic review of clinical cases

The occurrence of mucormycosis has been observed in individuals with COVID-19. However, there is limited information on the epidemiological factors, presentation, diagnostic certainty, and outcome of this infection in children. PubMed, MEDLINE, Scopus, Embase, Web of Science, LitCovid, and back-references of the identified manuscripts were systematically searched from December 2019 to March 2023. We have identified 14 cases of pediatric mucormycosis in patients with COVID-19. The median age of patients was 10.7 years. Among these cases, 10 were associated with active COVID-19. In 7 cases, the patients had pre-existing diabetes mellitus and concomitant diabetic ketoacidosis. Corticosteroids were administered to treat COVID-19 in 7 of the patients. The most common clinical presentation of the disease was rhino-orbital cerebral mucormycosis. Seven patients died (50%). Given the high mortality rate, clinicians should maintain a high level of clinical suspicion of mucormycosis in pediatric patients with COVID-19.

The Impact of Dimitrios P. Kontoyiannis on Mucormycosis Research

Dimitrios P [...].

Mucormycosis in children with cancer and hematopoietic cell transplant-A single center cohort study

Although mucormycosis is an important cause of morbidity and mortality in children with cancer, our understanding of the typical characteristics of these infections is incomplete. We reviewed all cases of mucormycosis diagnosed at a single pediatric cancer center over 5 decades to identify the clinical features of mucormycosis in pediatric oncology patients and to identify risk factors for mortality. There were 44 cases of mucormycosis diagnosed between 1970-2019. Most patients (89%) had hematological malignancies and a history of prolonged and severe neutropenia (91%). In this series, hyperglycemia and exposure to corticosteroids were common. Pulmonary (36%) and disseminated infections (32%) were most common; rhino-orbital-cerebral infections were relatively infrequent (11%). Rhizopus spp. was the most common etiological agent (40%) followed by Mucor spp. (31%), and Cunninghamella spp. (19%). Overall mortality was 44% and 51% and attributable mortality was 39% and 41% at the end of antifungal therapy and end of follow up, respectively. Attributable mortality fell to 18% in 2010-2019, from 58-60% in previous decades; adjunctive surgery was associated with decreased mortality. Mortality remains unacceptably high despite aggressive antifungal therapy and adjunctive surgery, suggesting novel therapeutic strategies are needed.

The outcome and the risk factors of mucormycosis among patients with hematological diseases: a systematic and meta-analysis

Objectives

Mucorale has come into a significant pathogen over recent decades. Nonetheless, mucormycosis-related mortality rates among patients with hematological disorders remain unascertained. Thus, we conducted a meta-analysis to determine mortality rates of mucormycosis in patients with hematology-related conditions.

Methods

We scoured PubMed, Embase, and Web of Science for original papers exploring the intersection of Mucormycosis and Hematological Diseases (from 2000 to 2022). We scrutinized the overall mortality across three distinct periods, as well as differentiating between high-income and middle-income nations. We further evaluated the pooled mortality and the risk differential (RD) across several subgroups.

Results

The overall mortality rate for hematology patients with mucormycosis was 61%, within a 95% confidence interval (CI) of 0.54-0.68. A significant observation was that mortality rates were somewhat lower in high-income countries compared to middle-income countries (0.60 versus 0.64, p = 0.45). Importantly, we discovered that a combination of surgical and medical treatment significantly improved survival rates compared to medical treatment alone [mortality 0.49 versus 0.67, RD -0.19 (95%CI -0.38-0.00, I2 63.7%)]. As might be expected, disseminated mucormycosis posed a significantly higher risk of death compared to isolated mucormycosis [0.60 versus 0.57, RD death 0.16 (95%CI 0.03-0.28)]. Additionally, our analysis showed no discernible differences in survival rates between genders, between patients with and without breakthrough infection, between those who received mucor-active or mucor-inactive drugs prior to mucor infection, or between those on a multi-drug regimen and those on a single drug treatment.

Conclusion

Despite the high mortality rates associated with mucormycosis in patients with hematological disorders, those receiving both medical and surgical interventions, as well as those with isolated infection sites, exhibited improved survival outcomes. Conversely, factors such as gender, the presence of breakthrough infection, the use of mucor-active drugs before mucor infection, and multi-drug administration did not significantly influence patient outcomes.

Epidemiology, Modern Diagnostics, and the Management of Mucorales Infections

Mucormycosis is an uncommon, yet deadly invasive fungal infection caused by the Mucorales moulds. These pathogens are a WHO-assigned high-priority pathogen group, as mucormycosis incidence is increasing, and there is unacceptably high mortality with current antifungal therapies. Current diagnostic methods have inadequate sensitivity and specificity and may have issues with accessibility or turnaround time. Patients with diabetes mellitus and immune compromise are predisposed to infection with these environmental fungi, but COVID-19 has established itself as a new risk factor. Mucorales also cause healthcare-associated outbreaks, and clusters associated with natural disasters have also been identified. Robust epidemiological surveillance into burden of disease, at-risk populations, and emerging pathogens is required. Emerging serological and molecular techniques may offer a faster route to diagnosis, while newly developed antifungal agents show promise in preliminary studies. Equitable access to these emerging diagnostic techniques and antifungal therapies will be key in identifying and treating mucormycosis, as delayed initiation of therapy is associated with higher mortality.

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.

Clinical Features and Treatment Progress of Invasive Mucormycosis in Patients with Hematological Malignancies

The incidence rate of invasive mucormycosis (IM) in patients with hematological malignancies (HMs) is increasing year by year, ranging from 0.07% to 4.29%, and the mortality rate is mostly higher than 50%. With the ongoing pandemic of COVID-19, COVID-19-associated mucormycosis (CAM) also became a global health threat. Patients with high risk factors such as active HMs, relapsed/refractory leukemia, prolonged neutropenia may still develop breakthrough mucormycosis (BT-MCR) even under the prophylaxis of Mucorales-active antifungals, and such patients often have higher mortality. Rhizopus spp. is the most common genus associated with IM, followed by Mucor spp. and Lichtheimia spp. Pulmonary mucormycosis (PM) is the most common form of IM in patients with HMs, followed by rhino-orbital-cerebral mucormycosis (ROCM) and disseminated mucormycosis. The prognosis of IM patients with neutrophil recovery, localized IM and receiving early combined medical-surgical therapy is usually better. As for management of the disease, risk factors should be eliminated firstly. Liposome amphotericin B (L-AmB) combined with surgery is the initial treatment scheme of IM. Those who are intolerant to L-AmB can choose intravenous formulations or tablets of isavuconazole or posaconazole. Patients who are refractory to monotherapy can turn to combined antifungals therapy.

Isolated cerebral mucormycosis that looks like stroke and brain abscess: A case report and review of the literature

BACKGROUND

Cerebral mucormycosis is an infectious disease of the brain caused by fungi of the order Mucorales. These infections are rarely encountered in clinical practice and are often misdiagnosed as cerebral infarction or brain abscess. Increased mortality due to cerebral mucormycosis is closely related to delayed diagnosis and treatment, both of which present unique challenges for clinicians.

CASE SUMMARY

Cerebral mucormycosis is generally secondary to sinus disease or other disseminated disease. However, in this retrospective study, we report and analyze a case of isolated cerebral mucormycosis.

CONCLUSION

The constellation of symptoms including headaches, fever, hemiplegia, and changes in mental status taken together with clinical findings of cerebral infarction and brain abscess should raise the possibility of a brain fungal infection. Early diagnosis and prompt initiation of antifungal therapy along with surgery can improve patient survival.

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.

New insights on mucormycosis and its association with the COVID-19 pandemic

COVID-19 continues to cause significant fatality worldwide. Glucocorticoids prove to play essential roles in COVID-19 management; however, the extensive use of steroids together with the virus immune dysregulation may increase the danger of secondary infections with mucormycosis, an angioinvasive fungal infection. Unfortunately, a definite correlation between COVID-19 and elevated mucormycosis infection cases is now clear worldwide. In this review, we discuss the historical record and epidemiology of mucormycosis as well as pathogenesis and associated host immune response, risk factors, clinical presentation, diagnosis and treatment. Special emphasis is given to its association with the current COVID-19 pandemic, including latest updates on COVID-19-associated mucormycosis cases globally, with recommendations for efficacious management.

Has the mortality from pulmonary mucormycosis changed over time? A systematic review and meta-analysis

OBJECTIVES

Pulmonary mucormycosis (PM) is increasingly being reported in immunocompromised patients and has a high mortality. Our aim was to assess the mortality of PM and its trend over time. We also evaluated the role of combined medical-surgical therapy in PM.

METHODS

We performed a systematic review of Pubmed, Embase, and Cochrane central databases. Studies were eligible if they described at least five confirmed cases of PM and reported mortality. We also assessed the effect of combined medical-surgical therapy versus medical treatment alone on PM mortality. We used a random-effects model to estimate the pooled mortality of PM and compared it across three time periods. The factors influencing mortality were assessed using meta-regression. We evaluated the risk difference (RD) of death in the following: subjects undergoing combined medical-surgical therapy versus medical therapy alone, subjects with isolated PM versus disseminated disease, and PM in diabetes mellitus (DM) versus non-DM as a risk factor.

RESULTS

We included 79 studies (1544 subjects). The pooled mortality of PM was 57.1% (95% confidence interval [CI] 51.7-62.6%). Mortality improved significantly over time (72.1% versus 58.3% versus 49.8% for studies before 2000, 2000-2009, and 2010-2020, respectively, p 0.00001). This improved survival was confirmed in meta-regression after adjusting for the study design, the country's income level, and the sample size. Combined medical-surgical therapy was associated with a significantly lower RD (95%CI) of death: -0.32 (-0.49 to -0.16). The disseminated disease had a higher risk of death than isolated PM, but DM was not associated with a higher risk of death than other risk factors.

CONCLUSIONS

While PM is still associated with high mortality, we noted improved survival over time. Combined medical-surgical therapy improved survival compared to medical treatment alone.

Distribution of invasive fungal infections: Molecular epidemiology, etiology, clinical conditions, diagnosis and risk factors: A 3-year experience with 490 patients under intensive care

Recently, the prevalence of invasive fungal infections (IFIs) is rising. The global mortality rate of IFIs is 10-49%. This study aimed to determine the prevalence, the causative agents, and the risk factors associated with the invasive fungal infections in a tertiary health center to provide valid decision-grounds for healthcare professionals to effectively prevent, control, and treat fungal infections. The current study was conducted on 1477 patients suspected to have systemic fungal infections from different units of the hospital. After screening using routine mycological examination, the patients were confirmed with complementary mycological and molecular methods. Patients were included based on the confirmed diagnosis of IFI and excluded based on lack of a microbiologically and histologically proven diagnosis of IFI. Of the 1477 patients recruited in this study, confirmed cases of fungal infection were 490 (169 proven; 321 cases probable). Among the fungi recovered, Candida species had the highest frequency 337 (68.8%) followed by Aspergillus species 108 (22.1%), Zygomycetes species 21 (4.3%), non-Candida yeast 9 (1.8%). Others were black fungi 5 (1%), mycetoma agents 5 (1%), Fusarium 4 (0.8%), and Trichoderma (0.2%). Hematologic malignancies and diabetes mellitus were the most common underlying diseases among IFI-confirmed patients. This study observed an increased frequency of invasive candidiasis with non-albicans Candida and other invasive saprophytic fungal infections. The increased rate of invasive candidiasis with non-albicans agents highlights a new perspective in the epidemiology and treatment of invasive fungal infections.

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.

Treatment of invasive fungal diseases in cancer patients-Revised 2019 Recommendations of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Oncology (DGHO)

BACKGROUND

Invasive fungal diseases remain a major cause of morbidity and mortality in cancer patients undergoing intensive cytotoxic therapy. The choice of the most appropriate antifungal treatment (AFT) depends on the fungal species suspected or identified, the patient's risk factors (eg length and depth of granulocytopenia) and the expected side effects.

OBJECTIVES

Since the last edition of recommendations for 'Treatment of invasive fungal infections in cancer patients' of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) in 2013, treatment strategies were gradually moving away from solely empirical therapy of presumed or possible invasive fungal diseases (IFDs) towards pre-emptive therapy of probable IFD.

METHODS

The guideline was prepared by German clinical experts for infections in cancer patients in a stepwise consensus process. MEDLINE was systematically searched for English-language publications from January 1975 up to September 2019 using the key terms such as 'invasive fungal infection' and/or 'invasive fungal disease' and at least one of the following: antifungal agents, cancer, haematological malignancy, antifungal therapy, neutropenia, granulocytopenia, mycoses, aspergillosis, candidosis and mucormycosis.

RESULTS

AFT of IFDs in cancer patients may include not only antifungal agents but also non-pharmacologic treatment. In addition, the armamentarium of antifungals for treatment of IFDs has been broadened (eg licensing of isavuconazole). Additional antifungals are currently under investigation or in clinical trials.

CONCLUSIONS

Here, updated recommendations for the treatment of proven or probable IFDs are given. All recommendations including the levels of evidence are summarised in tables to give the reader rapid access to key information.

A Radical Approach to Acute Lymphoblastic Leukemia Treatment: A Case Study of a Veterinarian Specializing in Livestock who Developed Disseminated Mucormycosis during Induction Therapy

Mucormycosis has emerged as the third-most common fungal mycosis and is one of the most fatal molds. We herein report a case study of a 30-year-old woman who was a veterinarian, specializing in livestock, who developed disseminated mucormycosis during induction therapy for acute lymphoblastic leukemia. We successfully used a radical approach for treatment, including a surgical procedure and allogeneic transplantation, with continuous administration of antifungal agents. Reports of successful treatments are extremely rare, and our case has had the longest documented remission from disseminated disease. We speculate that our case's occupational environment may represent a risk factor for development of mucormycosis.

Pediatric Mucormycosis: A 10-Year Systematic Review of Reported Cases and Review of the Literature

Mucormycosis is a severe infection that affects a variety of patients, including immunocompromised children and neonates. Given improved survival rates from advances in the treatment of malignancies, the population at risk for mucormycosis is increasing. We conducted a systematic review of cases of mucormycosis in children in the English-language literature reported between August 2008 and June 2017 and analyzed the clinical characteristics, diagnosis, management, and outcome of those infections. The most common underlying diagnoses included neutropenia (41%), hematologic malignancy (39%), prematurity (13%), and hematopoietic stem cell transplant (11%). Sinus disease (28%) and disseminated disease (24%) were the most common presentations. Rhizopus spp were the most common organisms isolated (22%). Amphotericin B remains the backbone of treatment and was prescribed in 86% of these cases. The resulting mortality rate remains high (32%). We provide here the results of a literature review of mucormycosis in children, including its epidemiology and clinical manifestations, and describe current advances in its diagnosis and treatment.

A Guide to Investigating Suspected Outbreaks of Mucormycosis in Healthcare

This report serves as a guide for investigating mucormycosis infections in healthcare. We describe lessons learned from previous outbreaks and offer methods and tools that can aid in these investigations. We also offer suggestions for conducting environmental assessments, implementing infection control measures, and initiating surveillance to ensure that interventions were effective. While not all investigations of mucormycosis infections will identify a single source, all can potentially lead to improvements in infection control.

Animal Models to Study Mucormycosis

Mucormycosis is a rare but often fatal or debilitating infection caused by a diverse group of fungi. Animal models have been crucial in advancing our knowledge of mechanisms influencing the pathogenesis of mucormycoses, and to evaluate therapeutic strategies. This review describes the animal models established for mucormycosis, summarizes how they have been applied to study mucormycoses, and discusses the advantages and limitations of the different model systems.

Disease Entities in Mucormycosis

Mucormycosis is an emerging life-threatening fungal infection caused by Mucorales. This infection occurs mainly in immunocompromised patients, especially with hematological malignancy, transplantation, or diabetes mellitus. Rhino-orbito-cerebral and pulmonary mucormycosis are the predominant forms. Interestingly, location is associated with the underlying disease as pulmonary mucormycosis is more frequent in hematological malignancy patients whereas rhino-orbito-cerebral mucormycosis is associated with diabetes. Cutaneous mucormycosis results from direct inoculation, mainly after trauma or surgery. Gastro-intestinal mucormycosis occurs after ingestion of contaminated food or with contaminated device and involves the stomach or colon. Disseminated disease is the most severe form and is associated with profound immunosuppression. Uncommon presentations with endocarditis, osteoarticluar or isolated cerebral infections are also described. Finally, health-care associated mucormycosis is a matter of concern in premature newborns and burn units. Clinical symptoms and CT scan findings are not specific, only the early reversed halo sign is associated with pulmonary mucormycosis. Circulating Mucorales DNA detection is a recent promising diagnostic tool that may lead to improving the diagnosis and prompting therapeutic initiation that should include antifungal treatment, correction of the underlying disease and surgery when feasible.

In Vitro and In Vivo Evaluation of Voriconazole-Containing Antifungal Combinations against Mucorales Using a Galleria mellonella Model of Mucormycosis

Mucorales are resistant to most antifungals. Mucormycosis associated mortality is unacceptable and new treatment approaches are needed. The objectives of this work were (i) to evaluate the nature and intensity of the in vitro effect of three drugs combinations which included voriconazole (plus amphotericin B, posaconazole and caspofungin) against 25 strains of six different Mucorales species; (ii) to evaluate a Galleria mellonella mucormycosis model; and (iii) to establish if any in vitro⁻in vivo correlation exists. As expected, amphotericin B and posaconazole were the most active drugs when tested alone. However, species-specific differences were found. The ΣFICs varied according to the used combination. Only five strains showed synergism when voriconazole was combined with posaconazole and three strains when combined with amphotericin B. Microscopic hyphae alteration were observed for some isolates when confronted against drugs combinations. Using a Galleria mellonella mucormycosis model, better survival was seen in voriconazole plus amphotericin B and plus caspofungin combined treatments when compared with AMB alone for R. microsporus. These survival improvements were obtained using a 32-fold lower amphotericin B doses when combined with VRC than when treated with the polyene alone. These lower antifungal doses emulate the antifungal concentrations where the microscopic hyphae alterations were seen.

Challenges in the diagnosis and treatment of mucormycosis

The diagnosis and treatment of mucormycosis are challenging. The incidence of the disease seems to be increasing. Hematological malignancies are the most common underlying disease in countries with high income and uncontrolled diabetes in developing countries. Clinical approach to diagnosis lacks sensitivity and specificity. Radiologically, multiple (≥10) nodules and pleural effusion are reportedly associated with pulmonary mucormycosis. Another finding on computerized tomography (CT) scan, which seems to indicate the presence of mucormycosis, is the reverse halo sign. Microscopy (direct and on histopathology) and culture are the cornerstones of diagnosis. Molecular assays can be used either for detection or identification of mucormycetes, and they can be recommended as valuable add-on tools that complement conventional diagnostic procedures. Successful management of mucormycosis is based on a multimodal approach, including reversal or discontinuation of underlying predisposing factors, early administration of active antifungal agents at optimal doses, complete removal of all infected tissues, and use of various adjunctive therapies. Our armamentarium of antifungals is slightly enriched by the addition of two newer azoles (posaconazole and isavuconazole) to liposomal amphotericin B, which remains the drug of choice for the initial antifungal treatment, according to the recently published guidelines by ECIL-6, as well as those published by ECMM/ESCMID. Despite the efforts for better understanding of the pathogenesis, early diagnosis and aggressive treatment of mucormycosis, the mortality rate of the disease remains high.

Successful treatment of pulmonary mucormycosis in two pediatric hematopoietic stem cell transplant patients

Pulmonary mucormycosis diagnosed immediately after hematopoietic stem cell transplantation frequently portends a poor prognosis. However, here we describe two cases in children that were treated successfully to highlight the efficacy of a multidisciplinary approach. Despite diagnosis in the immediate post-transplant period and requirement for ongoing immunosuppression to prevent or treat GVHD, both are long-term survivors due to early surgical debridement with transfusion support and prompt initiation of targeted antifungal therapy. In the absence of evidence-based treatment guidelines, survival of pulmonary mucormycosis is achievable even in high-risk patients with a multidisciplinary team to guide management.

What, where and why: exploring fluorodeoxyglucose-PET's ability to localise and differentiate infection from cancer

PURPOSE OF REVIEW

To review the utility of FDG-PET imaging in detecting the cause of fever and infection in patients with cancer.

RECENT FINDINGS

FDG-PET has been shown to have high sensitivity and accuracy for causes of neutropenic fever, leading to higher diagnostic certainty in this group. Recent advances in pathogen-specific labelling in PET to identify Aspergillus spp. and Yersinia spp. infections in mice, as well as differentiating between Gram-positive, Gram-negative and mycobacterial infections are promising.

SUMMARY

Patients with cancer are vulnerable to infection and fever, and the causes of these are frequently unclear using conventional diagnostic methods leading to high morbidity and mortality, length of stay and costs of care. FDG-PET/CT, with its unique complementary functional and anatomical information as well as its whole-body imaging capability, has demonstrated use in detecting occult infection in immunocompromised patients, including invasive fungal and occult bacterial infections, as well as defining extent of infection. By demonstrating disease resolution following treatment and allowing earlier cessation of therapy, FDG-PET acts as a key tool for antimicrobial and antifungal stewardship. Limitations include at times poor differentiation between infection, malignancy and sterile inflammation, however, exciting new technologies specific to infectious pathogens may help alleviate that issue. Further prospective randomised research is needed to explore these benefits in a nonbiased fashion.

Mucormycosis in Iran: A six-year retrospective experience

Mucormycosis is a devastating infection caused by Mucoralean fungi (Mucormycotina, Mucorales). Data concerning the global epidemiology of mucormycosis are scarce and little is known about the characteristics of mucormycosis in Iran. In this study, we aimed to understand the distribution of this infection in Iran retrospectively and to ascertain whether the patterns of infection are associated with specific host factors or not. A total of 208 cases were included in this study occurring during 2008-2014 and were validated according to (EORTC/MSG) criteria. A rising trend as significant increase from 9.7% in 2008 to 23.7% in 2014 was observed. The majority of patients were female (51.4%) with median age of 50 and the infections were seen mostly in autumn season (39.4%). Diabetes mellitus (75.4%) was the most common underlying condition and sinus involvement (86%) was the mostly affected site of infection. Amphotericin B (AmB) was the drug of choice for the majority of cases. Sixty four isolates did not show any growth in the lab and only 21 cases were evaluated by ITS sequencing, among them; Rhizopus arrhizus var. arrhizus was the dominant species. Considering the high mortality rate of mucormycosis, early and accurate diagnosis, with the aid of molecular methods may provide accurate treatments and improve the survival rate. Therefore, increased monitoring and awareness of this life-threatening disease is critical.

Fungal Pneumonia in Patients with Hematologic Malignancies and Hematopoietic Cell Transplantation

Invasive fungal infections, which occur primarily as a consequence of prolonged neutropenia and immunosuppression, are a life-threatening complication seen among patients with hematologic malignancies. The routine use of triazole antifungal prophylaxis, enhanced diagnostics, and newer antifungal agents have led to improvements in the care of fungal pneumonias, but invasive fungal infections remain a major cause of morbidity and mortality. This article covers risk factors for major fungal infections, diagnostic approaches, and treatment options for specific fungal pathogens, including Aspergillus and Mucorales species, and discusses current approved strategies for prevention of common and uncommon fungal pneumonias.

Invasive mould infections in the ICU setting: complexities and solutions

Infections caused by filamentous fungi represent a major burden in the ICU. Invasive aspergillosis is emerging in non-neutropenic individuals with predisposing conditions, e.g. corticosteroid treatment, chronic obstructive pulmonary disease, liver cirrhosis, solid organ cancer, HIV infection and transplantation. Diagnosis is challenging because the signs and symptoms are non-specific, and initiation of additional diagnostic examinations is often delayed because clinical suspicion is low. Isolation of an Aspergillus species from the respiratory tract in critically ill patients, and tests such as serum galactomannan, bronchoalveolar lavage 1-3-β-d-glucan and specific PCR should be interpreted with caution. ICU patients should start adequate antifungal therapy upon suspicion of invasive aspergillosis, without awaiting definitive proof. Voriconazole, and now isavuconazole, are the drugs of choice. Mucormycosis is a rare, but increasingly prevalent disease that occurs mainly in patients with uncontrolled diabetes mellitus, immunocompromised individuals or previously healthy patients with open wounds contaminated with Mucorales. A high proportion of cases are diagnosed in the ICU. Rapidly progressing necrotizing lesions in the rhino-sinusal area, the lungs or skin and soft tissues are the characteristic presentation. Confirmation of diagnosis is based on demonstration of tissue invasion by non-septate hyphae, and by new promising molecular techniques. Control of underlying predisposing conditions, rapid surgical resection and administration of liposomal amphotericin B are the main therapeutic actions, but new agents such as isavuconazole are a promising alternative. Patients with mucormycosis receive a substantial part of their care in ICUs and, despite advances in diagnosis and treatment, mortality remains very high.

Evaluation of 30 cases of mucormycosis at a university hospital in Iran

Mucormycosis is a deadly invasive fungal infection and mainly affects immunocompromised patients. To investigate the clinical features of patients who developed mucormycosis and to determine the parameters, which influenced the outcome following mycotic infection. The current investigation retrospectively evaluated the demographic characteristics, clinical features, therapeutic data, as well as the outcomes of treatment in all cases of proven and probable mucormycosis diagnosed from 2002 until 2016 in our hospital. A total of thirty cases were recorded. Rhizopus spp. was the predominant pathogen among the identified Mucorales (26.7%). Diabetes mellitus (46.7%) and haematological malignancy (40%), were the most common underlying diseases. With regard to predisposing factors, neutropenia (43.3%) and chemotherapy (40%) were the leading concomitant parameters. The most frequent sites of infection were lung (30%) and sinus (26.7%), whereas disseminated infection was also found in nine of 30 patients (30%). Neutropenia remained the only independent factor associated with mortality (Relative Risk=3.557, 95% CI=1.365-9.271, P=.009). Diagnostic delay -either due to delayed presentation of patients to our centre or insufficient awareness about invasive fungal infection among our clinicians- is a likely explanation for such a high mortality rate in our series.

The Changing Epidemiology of Invasive Fungal Infections

Invasive fungal infections (IFI) are an emerging problem worldwide with invasive candidiasis and candidemia responsible for the majority of cases. This is predominantly driven by the widespread adoption of aggressive immunosuppressive therapy among certain patient populations (e.g., chemotherapy, transplants) and the increasing use of invasive devices such as central venous catheters (CVCs). The use of new immune modifying drugs has also opened up an entirely new spectrum of patients at risk of IFIs. While the epidemiology of candida infections has changed in the last decade, with a gradual shift from C. albicans to non-albicans candida (NAC) strains which may be less susceptible to azoles, these changes vary between hospitals and regions depending on the type of population risk factors and antifungal use. In certain parts of the world, the incidence of IFI is strongly linked to the prevalence of other disease conditions and the ecological niche for the organism; for instance cryptococcal and pneumocystis infections are particularly common in areas with a high prevalence of HIV disease. Poorly controlled diabetes is a major risk factor for invasive mould infections. Environmental factors and trauma also play a unique role in the epidemiology of mould infections, with well-described hospital outbreaks linked to the use of contaminated instruments and devices. Blastomycosis is associated with occupational exposure (e.g., forest rangers) and recreational activities (e.g., camping and fishing).The true burden of IFI is probably an underestimate because of the absence of reliable diagnostics and lack of universal application. For example, the sensitivity of most blood culture systems for detecting candida is typically 50 %. The advent of new technology including molecular techniques such as 18S ribosomal RNA PCR and genome sequencing is leading to an improved understanding of the epidemiology of the less common mould and dimorphic fungal infections. Molecular techniques are also providing a platform for improved diagnosis and management of IFI.Many factors affect mortality in IFI, not least the underlying medical condition, choice of therapy, and the ability to achieve early source control. For instance, mortality due to pneumocystis pneumonia in HIV-seronegative individuals is now higher than in seropositive patients. Of significant concern is the progressive increase in resistance to azoles and echinocandins among candida isolates, which appears to worsen the already significant mortality associated with invasive candidiasis. Mortality with mould infections approaches 50 % in most studies and varies depending on the site, underlying disease and the use of antifungal agents such as echinocandins and voriconazole. Nevertheless, mortality for most IFIs has generally fallen with advances in medical technology, improved care of CVCs, improved diagnostics, and more effective preemptive therapy and prophylaxis.

Prevalence, clinical and economic burden of mucormycosis-related hospitalizations in the United States: a retrospective study

Background

Mucormycosis is a rare but devastating fungal infection primarily affecting immunocompromised patients such as those with hematological malignancy, bone marrow and solid organ transplantation, and patients with diabetes, and, even more rarely, immunocompetent patients. The objective of this study was to assess the prevalence and burden, both clinical and economic, of mucormycosis among hospitalized patients in the U.S.

Methods

This is a retrospective study using the Premier Perspective^TM Comparative Database, with more than 560 participating hospitals covering 104 million patients (January 2005-June 2014). All hospitalizations in the database were evaluated for the presence of mucormycosis using either an ICD-9 code of 117.7 or a positive laboratory result for Mucorales. Hospitalizations were further required to have prescriptions of amphotericin B or posaconazole to be considered as mucormycosis-related hospitalizations. The prevalence of mucormycosis-related hospitalizations among all hospital discharges was estimated. Mortality rate at discharge, length of hospital stay, and readmission rates at 1 and 3 months were evaluated among mucormycosis-related hospitalizations. Cost per hospital stay and average per diem cost (inflated to 2014 USD) were reported.

Results

The prevalence of mucormycosis-related hospitalizations was estimated as 0.12 per 10,000 discharges during January 2005-June 2014. It increased to 0.16 per 10,000 discharges if the definition of mucormycosis was relaxed to not require the use of amphotericin B or posaconazole. The median length of stay was 17 days, with 23% dead at discharge; readmission rates were high, with 30 and 37% of patients readmitted within one and three months of discharge, respectively. The average cost per hospital stay was $112,419, and the average per diem cost was $4,096.

Conclusions

The study provides a recent estimate of the prevalence and burden of mucormycosis among hospitalized patients. The high clinical and economic burden associated with mucormycosis highlights the importance of establishing active surveillance and optimizing prophylactic and active treatment in susceptible patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-016-2023-z) contains supplementary material, which is available to authorized users.

Cutaneous mucormycosis in advanced HIV disease

Angionvasive mucormycosis is an emerging fungal disease known to affect mainly diabetics or subjects with profound neutropenia. Infection usually occurs through the inhalation route, but cutaneous inoculation may occur after trauma or burns. However, mucormycosis remains unusual in HIV infection. We report a fatal case of cutaneous mucormycosis due to Rhizopus arrhizus involving the scalp following herpes zoster infection. The patient was a 42-year-old man with advanced AIDS failing on salvage antiretroviral therapy. The fungus was diagnosed on the basis of histopathology and culture. Our case emphasizes the need to consider mucormycosis in the differential diagnosis of necrotic cutaneous lesions in patients with late-stage HIV disease.

Influence of 5% dextrose volume on amphotericin B deoxycholate preparation

OBJECTIVES

Preparation of amphotericin B deoxycholate (AmB-d) in different volumes of 5% dextrose (D5W) was studied to investigate a interesting phenomenon that AmB-d was easy to bring pipe blockage when diluted in 500 ml but not in 50 ml.

METHODS

AmB-d (25 mg/vial) in 50 ml, 250 ml or 500 ml D5W was prepared. Fluids were collected before and after infusion, then were assayed by validated high-performance liquid chromatography (HPLC) method. Light obscuration assay was used to detect the particles in transfusions.

KEY FINDINGS

pH values of different volumes of D5W were all about 3.7, which was lower than the requirement of AmB-d package insert (pH > 4.2). The number of insoluble particles >10 μm/25 μm in 25 mg/500 ml infusions exceeded China Pharmacopoeia limit. Filters in 25 mg/500 ml infusion set were full of AmB-d after dripping slowly for 6 h, and 331.3 ml solution was left in the bottles and only 11.3% of AmB-d could flow out. Whereas the AmB-d infusion consists of 25 mg/50 ml, 25 mg/250 ml and 50 mg/500 ml could meet with China Pharmacopoeia standards, and they flowed out easily and completely.

CONCLUSIONS

In practice, 25 mg/250 ml and 50 mg/500 ml would be more suitable for clinical use, rather than 25 mg/500 ml. We provided a convenient method for AmB-d preparation.

Mucormycosis in Iran: a systematic review

Fungi in the order Mucorales cause acute, invasive and frequently fatal infections in susceptible patients. This study aimed to perform a systematic review of all reported mucormycosis cases during the last 25 years in Iran. After a comprehensive literature search, we identified 98 cases in Iran from 1990-2015. The mean patient age was 39.8 ± 19.2 years. Diabetes was the most common underlying condition (47.9%), and 22.4% of the patients underwent solid organ or bone marrow transplantation. The most common clinical forms of mucormycosis were rhinocerebral (48.9%), pulmonary (9.2%) and cutaneous (9.2%). Eight cases of disseminated disease were identified. Overall mortality in the identified cases was 40.8%, with the highest mortality rate in patients diagnosed with disseminated infection (75%). The mortality rate in rhinocerebral infection patients was significantly lower (45.8%). Rhinocerebral infection was the most common clinical manifestation in diabetes patients (72.9%). Patients were diagnosed using various methods including histopathology (85.7%), microscopy (12.3%) and culture (2.0%). Rhizopus species were the most prevalent (51.7%), followed by Mucor species (17.2%). Sixty-nine patients were treated with a combination of surgery and antifungal therapy (resulting survival rate, 66.7%). Owing to the high mortality rate of advanced mucormycosis, early diagnosis and treatment may significantly improve survival rates. Therefore, increased monitoring and awareness of this life-threatening disease is critical.

Mucormycosis in Australia: contemporary epidemiology and outcomes

Mucormycosis is the second most common cause of invasive mould infection and causes disease in diverse hosts, including those who are immuno-competent. We conducted a multicentre retrospective study of proven and probable cases of mucormycosis diagnosed between 2004-2012 to determine the epidemiology and outcome determinants in Australia. Seventy-four cases were identified (63 proven, 11 probable). The majority (54.1%) were caused by Rhizopus spp. Patients who sustained trauma were more likely to have non-Rhizopus infections relative to patients without trauma (OR 9.0, p 0.001, 95% CI 2.1-42.8). Haematological malignancy (48.6%), chemotherapy (42.9%), corticosteroids (52.7%), diabetes mellitus (27%) and trauma (22.9%) were the most common co-morbidities or risk factors. Rheumatological/autoimmune disorders occurred in nine (12.1%) instances. Eight (10.8%) cases had no underlying co-morbidity and were more likely to have associated trauma (7/8; 87.5% versus 10/66; 15.2%; p <0.001). Disseminated infection was common (39.2%). Apophysomyces spp. and Saksenaea spp. caused infection in immuno-competent hosts, most frequently associated with trauma and affected sites other than lung and sinuses. The 180-day mortality was 56.7%. The strongest predictors of mortality were rheumatological/autoimmune disorder (OR = 24.0, p 0.038 95% CI 1.2-481.4), haematological malignancy (OR = 7.7, p 0.001, 95% CI 2.3-25.2) and admission to intensive care unit (OR = 4.2, p 0.02, 95% CI 1.3-13.8). Most deaths occurred within one month. Thereafter we observed divergence in survival between the haematological and non-haematological populations (p 0.006). The mortality of mucormycosis remains particularly high in the immuno-compromised host. Underlying rheumatological/autoimmune disorders are a previously under-appreciated risk for infection and poor outcome.

Implementation of a Pan-Genomic Approach to Investigate Holobiont-Infecting Microbe Interaction: A Case Report of a Leukemic Patient with Invasive Mucormycosis

Disease can be conceptualized as the result of interactions between infecting microbe and holobiont, the combination of a host and its microbial communities. It is likely that genomic variation in the host, infecting microbe, and commensal microbiota are key determinants of infectious disease clinical outcomes. However, until recently, simultaneous, multiomic investigation of infecting microbe and holobiont components has rarely been explored. Herein, we characterized the infecting microbe, host, micro- and mycobiomes leading up to infection onset in a leukemia patient that developed invasive mucormycosis. We discovered that the patient was infected with a strain of the recently described Mucor velutinosus species which we determined was hypervirulent in a Drosophila challenge model and has a predisposition for skin dissemination. After completing the infecting M. velutinosus genome and genomes from four other Mucor species, comparative pathogenomics was performed and assisted in identifying 66 M. velutinosus-specific putatively secreted proteins, including multiple novel secreted aspartyl proteinases which may contribute to the unique clinical presentation of skin dissemination. Whole exome sequencing of the patient revealed multiple non-synonymous polymorphisms in genes critical to control of fungal proliferation, such as TLR6 and PTX3. Moreover, the patient had a non-synonymous polymorphism in the NOD2 gene and a missense mutation in FUT2, which have been linked to microbial dysbiosis and microbiome diversity maintenance during physiologic stress, respectively. In concert with host genetic polymorphism data, the micro- and mycobiome analyses revealed that the infection developed amid a dysbiotic microbiome with low α-diversity, dominated by staphylococci. Additionally, longitudinal mycobiome data showed that M. velutinosus DNA was detectable in oral samples preceding disease onset. Our genome-level study of the host-infecting microbe-commensal triad extends the concept of personalized genomic medicine to the holobiont-infecting microbe interface thereby offering novel opportunities for using synergistic genetic methods to increase understanding of infectious diseases pathogenesis and clinical outcomes.

Prospective pilot study of high-dose (10 mg/kg/day) liposomal amphotericin B (L-AMB) for the initial treatment of mucormycosis

BACKGROUND

Mucormycosis incidence is increasing and is associated with a high rate of mortality. Although lipid-based formulations of amphotericin B are the recommended first-line treatment, only one prospective trial in a limited number of patients has been performed to evaluate this regimen.

METHODS

Patients with proven or probable mucormycosis were included between June 2007 and March 2011. Patients were scheduled to receive 10 mg/kg/day liposomal amphotericin B (L-AMB) monotherapy for 1 month and surgery was performed when appropriate. The primary outcome was response rate at week 4 or at the end of treatment (EOT) if before week 4, evaluated by an independent committee. ClinicalTrials.gov Identifier: NCT00467883.

RESULTS

Forty patients were enrolled. Response was analysed in 33 patients at week 4. Most patients had a haematological malignancy as their primary underlying disease (53%). Seventy-one percent of patients underwent therapeutic surgery. The response rate at week 4 or at EOT was 36%, with 18% partial responses and 18% complete responses. The response rate at week 12 was 45%, with 13% partial responses and 32% complete responses. Overall mortality was 38% at week 12 and 53% at week 24. Serum creatinine doubled in 16 (40%) patients and returned to normal levels within 12 weeks in 10/16 (63%).

CONCLUSIONS

High-dose L-AMB for mucormycosis, in combination with surgery in 71% of cases, was associated with an overall response rate of 36% at week 4 and 45% at week 12 and creatinine level doubling in 40% of patients (transient in 63%). These results may serve as the basis for future clinical trials.

Stability in the cumulative incidence, severity and mortality of 101 cases of invasive mucormycosis in high-risk patients from 1995 to 2011: a comparison of eras immediately before and after the availability of voriconazole and echinocandin-amphotericin combination therapies

As invasive mucormycosis (IM) numbers rise, clinicians suspect prior voriconazole worsens IM incidence and severity, and believe combination anti-fungal therapy improves IM survival. To compare the cumulative incidence (CI), severity and mortality of IM in eras immediately before and after the commercial availability of voriconazole all IM cases from 1995 to 2011 were analysed across four risk-groups (hematologic/oncologic malignancy (H/O), stem cell transplantation (SCT), solid organ transplantation (SOT) and other), and two eras, E1 (1995-2003) and E2, (2004-2011). Of 101 IM cases, (79 proven, 22 probable): 30 were in E1 (3.3/year) and 71 in E2 (8.9/year). Between eras, the proportion with H/O or SCT rose from 47% to 73%, while 'other' dropped from 33% to 11% (P = 0.036). Between eras, the CI of IM did not significantly increase in SCT (P = 0.27) or SOT (P = 0.30), and patterns of anatomic location (P = 0.122) and surgical debridement (P = 0.200) were similar. Significantly more patients received amphotericin-echinocandin combination therapy in E2 (31% vs. 5%, P = 0.01); however, 90-day survival did not improve (54% vs. 59%, P = 0.67). Since 2003, the rise of IM reflects increasing numbers at risk, not prior use of voriconazole. Frequent combination of anti-fungal therapy has not improved survival.

Our 2014 approach to mucormycosis

Mucormycosis, previously termed as zygomycosis, is caused by fungi belonging to the order Mucorales and is a very severe disease in immunocompromised patients with an often unfavourable outcome. Given the high morbidity and mortality of mucormycosis, establishing a timely diagnosis followed by immediate treatment is of major importance. As randomised clinical trials are lacking, we present our current diagnostic and treatment pathways for mucormycosis in the immunocompromised host. Due to the difficulty to distinguish mucormycosis from other filamentous fungi, mucormycosis always has to be considered as differential diagnosis in predisposed patients. Diagnostic procedures comprise imaging, microscopy, culture and histopathology and need to be rigorously used. In patients with a high suspicion of mucormycosis, e.g. reversed halo sign on computed tomography scanning, our approach combines liposomal amphotericin B (LAmB) with surgical debridement. In light of the rapid deterioration and poor prognosis of these patients, we prefer a daily dose of LAmB of at least 5 mg kg(-1) despite nephrotoxicity. In patients with stable disease we switch to posaconazole 200 mg four times per day. In case of progression antifungal combination is an option.