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

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.

Invasive fungal disease in the immunocompromised host: changing epidemiology, new antifungal therapies, and management challenges

BACKGROUND

Invasive fungal disease (IFD) causes morbidity and mortality in immunocompromised hosts (ICHs). Based on increasing recognition of the impact of IFD on human disease, a recent WHO priority list identified key areas of need.

OBJECTIVES

This review examines changes in the epidemiology of IFD, in particular the emergence of antifungal-resistant pathogens and the current availability of rapid diagnostic tests and antifungal treatment options.

SOURCES

Literature between 2000 and January 2024 regarding fungal epidemiology, diagnostic tests, antifungal resistance, emerging fungal pathogens, and novel antifungal agents in both adult and paediatric ICH were reviewed.

CONTENT

We describe the changing epidemiology and continued burden and mortality of IFD in ICH. Furthermore, we discuss the emergence of antifungal-resistant organisms driven by new immunosuppressed populations, climate change, and antifungal exposure in the individual and environment. We highlight novel antifungal agents and how they will address current unmet needs.

IMPLICATIONS

The changing epidemiology and increased population at risk for IFD, lack of recognition or quantification of risks for IFD with new therapies, current gaps in the availability of rapid diagnostic tests, and the imminent availability of novel antifungals with distinct spectra of activity argue for improved availability of and access to rapid diagnostics, antifungal stewardship programmes, and global access to antifungal agents.

PCR diagnostic platforms for non-Aspergillus mold infections: ready for routine implementation in the clinic?

INTRODUCTION

While Aspergillus spp. remain the predominant cause of invasive mold infections, non-Aspergillus molds, such as the Mucorales or Fusarium spp., account for an increasing proportion of cases. The diagnosis of non-Aspergillus invasive mold infections (NAIMI) is challenging because of the low sensitivity and delay of conventional microbiological tests. Therefore, there is a particular interest to develop molecular tools for their early detection in blood or other clinical samples.

AREAS COVERED

This extensive review of the literature discusses the performance of Mucorales-specific PCR and other genus-specific or broad-range fungal PCR that can be used for the diagnosis of NAIMI in diverse clinical samples, with a focus on novel technologies.

EXPERT OPINION

PCR currently represents the most promising approach, combining good sensitivity/specificity and ability to detect NAIMI in clinical samples before diagnosis by conventional cultures and histopathology. Several PCR assays have been designed for the detection of Mucorales in particular, but also Fusarium spp. or Scedosporium/Lomentospora spp. Some commercial Mucorales PCRs are now available. While efforts are still needed for standardized protocols and the development of more rapid and simpler techniques, PCR is on the way to becoming an essential test for the early diagnosis of mucormycosis and possibly other NAIMIs.

A Diagnostic Approach to Fungal Pneumonia: An Infectious Diseases Perspective

Although bacteria significantly exceed fungi as the most common cause of lower respiratory tract infection, the incidence of fungal pneumonia is increasing because of a growing at-risk population of immunocompromised individuals as well as anthropogenic global heating and environmental disruption. When a patient presents with a clinical syndrome of pneumonia, a constellation of factors must be considered to determine the probability of a fungal pneumonia, including host factors, epidemiologic exposures, suggestive radiographic patterns, and the presence of a non-resolving pneumonia. In addition, knowledge of clinically important fungal pathogens, their epidemiology, and associated clinical syndromes are key in guiding appropriate diagnostic testing and result interpretation, and ultimately rendering a correct diagnosis of a fungal pneumonia. This article aims to provide a framework for the evaluation and appropriate diagnostic testing of patients with suspected fungal pneumonia.

Pharmacological management of invasive mold infections in solid organ transplant recipients

INTRODUCTION

Solid organ transplant (SOT) recipients face an increased susceptibility to invasive fungal infection (IFI) due to filamentous fungi. Post-transplant invasive aspergillosis (IA) and mucormycosis are related to exceedingly high mortality rates and graft loss risk, and its management involve a unique range of clinical challenges.

AREAS COVERED

First, the current treatment recommendations for IA and mucormycosis among SOT recipients are critically reviewed, including the supporting evidence. Next, we discussed particular concerns in this patient population, such as drug-drug interactions (DDIs) between triazoles and post-transplant immunosuppression or treatment-related toxicity. The role for immunomodulatory and host-targeted therapies is also considered, as well as the theoretical impact of the intrinsic antifungal activity of calcineurin inhibitors. Finally, a personal opinion is made on future directions in the pharmacological approach to post-transplant IFI.

EXPERT OPINION

Despite relevant advances in the treatment of mold IFIs in the SOT setting, such as the incorporation of isavuconazole (with lower incidence of DDIs and better tolerability than voriconazole), there remains a large room for improvement in areas such as the position of combination therapy or the optimal strategy for the reduction of baseline immunosuppression. Importantly, future studies should define the specific contribution of newer antifungal agents and classes.

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.