Invasive pulmonary aspergillosis in the intensive care unit: current challenges and best practices

Epidemiological characteristics of patients with invasive pulmonary aspergillosis infected with Aspergillus fumigatus from a tertiary hospital in Ningxia, China

Invasive pulmonary aspergillosis (IPA) is a severe fungal infection primarily caused by Aspergillus fumigatus, representing a significant burden on public health. This study aims to address the limitations in the epidemiological characteristics, risk factors and diagnostic approaches for IPA by identifying clinical characteristics, laboratory findings, and chest CT imaging features that distinguish IPA from Aspergillus fumigatus colonization (AFC). We conducted a retrospective analysis of 249 hospitalized patients, including 77 with IPA and 172 with AFC, at Ningxia Medical University General Hospital from January 2018 to December 2023. Our findings revealed that patients with IPA exhibited higher rates of hemoptysis, dyspnea, and fever compared to those with AFC. Laboratory results indicated elevated levels of galactomannan (GM), white blood cell count (WBC), erythrocyte sedimentation rate (ESR), and platelet count in IPA patients. Chest computed tomography imaging studies showed higher incidences of cavity, consolidation, ground-glass opacity, and halo sign in IPA patients. Voriconazole was the primary treatment for 75.3% of IPA patients, who also had longer hospital stays and higher treatment costs. Multivariate logistic regression identified GM, ESR, chronic obstructive pulmonary disease (COPD), and hypertension as significant risk factors for IPA. Our study highlights the necessity of developing enhanced diagnostic models that integrate GM and ESR biomarkers to improve the specificity and sensitivity of IPA diagnosis. These findings provide valuable insights for early diagnosis and optimized treatment strategies, potentially improving patient outcomes and reducing healthcare costs.

Invasive fungal infections in patients with liver disease: immunological and clinical considerations for the intensive care unit

Patients with liver disease in the intensive care unit (ICU) face a unique susceptibility to infection due to the complex immune dysfunction resulting from hepatic failure. Bacterial infections are commonly present in these patients upon arrival to the hospital, often being the primary reason for ICU admission. In contrast, invasive fungal infections (IFIs) afflict a smaller percentage of patients and are usually discovered in the course of the ICU stay. IFI diagnosis in the ICU, particularly in patients with liver disease, is often delayed or overlooked, contributing to the extremely high ICU mortality associated with IFI in these patients despite the availability of effective (and largely safe) antifungal therapy. Thus, to improve outcomes, it is crucial for intensive care clinicians to be vigilant for IFIs in patients with liver disease. This review aims to contribute to the intensive care literature in this regard. We begin with an overview of normal antifungal immunity followed by a summary of how it may become compromised in the setting of hepatic dysfunction. Next, a general discussion of IFIs in liver disease is presented and then the three most relevant fungal pathogens, namely Candida, Aspergillus, and Cryptococcus, are individually examined. This review concludes by highlighting key knowledge and practice gaps that require attention by the scientific and clinical communities in the coming years.

Therapeutic drug monitoring-guided high-dose isavuconazole therapy for invasive pulmonary aspergillosis in a patient on extracorporeal membrane oxygenation support

We review the case of a 58-year-old female on extracorporeal membrane oxygenation (ECMO) support diagnosed with invasive pulmonary aspergillosis (IPA). Intravenous isavuconazole was started, requiring dose escalation to achieve isavuconazole trough concentration (ISA-Cmin) within the therapeutic range (2.5-5.0 μg/mL). For more than 4 months, she maintained a dose of 200 mg q12h, with a median ISA-Cmin of 3.4 (interquartile range [IQR]: 3.1-4.9) µg/mL. Throughout this interval, 17 assessments of ISA-Cmin were performed (weekly). Of these, 82% (14/17) were within the therapeutic range, with an intra-individual variability of 36.8%. Although no signs of hepatotoxicity were observed, she experienced short-term gastrointestinal adverse events related to potential isavuconazole over-exposure (ISA-Cmin > 5.0 μg/mL). ECMO circuit changes did not appear to affect ISA-Cmin. She was not obese (IMC ≈ 25 kg/m2) and did not require other extracorporeal therapy, but hypoalbuminemia may have contributed to an increase in unbound isavuconazole fraction and consequently its clearance.

Invasive Aspergillosis in the Intensive Care Unit

Invasive aspergillosis (IA) is a fungal infection, which has traditionally been associated with neutropenia and immunosuppressive therapies. Our understanding of invasive aspergillosis has been evolving and, in the past few decades, IA among ICU patients has been recognized as a common infection and has become more widely recognized. The diagnosis and management of invasive aspergillosis in the ICU is particularly challenging, due to the unstable clinical condition of the patients, lack of diagnostic markers, increased risk of further clinical deterioration, multiple comorbidities, and a need for early assessment and treatment. In this article, we will discuss the challenges and pitfalls of the diagnosis and management of invasive aspergillosis in an ICU setting, along with a review of the current literature that is pertinent and specific to this population.

Acute Invasive Pulmonary Aspergillosis: Clinical Presentation and Treatment

Among all clinical manifestations of pulmonary aspergillosis, invasive pulmonary aspergillosis (IPA) is the most acute presentation. IPA is caused by Aspergillus hyphae invading the pulmonary tissue, causing either tracheobronchitis and/or bronchopneumonia. The degree of fungal invasion into the respiratory tissue can be seen as a spectrum, going from colonization to deep tissue penetration with angio-invasion, and largely depends on the host's immune status. Patients with prolonged, severe neutropenia and patients with graft-versus-host disease are at particularly high risk. However, IPA also occurs in other groups of immunocompromised and nonimmunocompromised patients, like solid organ transplant recipients or critically ill patients with severe viral disease. While a diagnosis of proven IPA is challenging and often warranted by safety and feasibility, physicians must rely on a combination of clinical, radiological, and mycological features to assess the likelihood for the presence of IPA. Triazoles are the first-choice regimen, and the choice of the drug should be made on an individual basis. Adjunctive therapy such as immunomodulatory treatment should also be taken into account. Despite an improving and evolving diagnostic and therapeutic armamentarium, the burden and mortality of IPA still remains high. This review aims to give a comprehensive and didactic overview of the current knowledge and best practices regarding the epidemiology, clinical presentation, diagnosis, and treatment of acute IPA.

A Multiplex PCR Melting-Curve-Analysis-Based Detection Method for the Discrimination of Five Aspergillus Species

Aspergillus mold is a ubiquitously found, airborne pathogen that can cause a variety of diseases from mild to life-threatening in severity. Limitations in diagnostic methods combined with anti-fungal resistance render Aspergillus a global emerging pathogen. In industry, Aspergilli produce toxins, such as aflatoxins, which can cause food spoilage and pose public health risk issues. Here, we report a multiplex qPCR method for the detection and identification of the five most common pathogenic Aspergillus species, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger, Aspergillus terreus, and Aspergillus nidulans. Our approach exploits species-specific nucleotide polymorphisms within their ITS genomic regions. This novel assay combines multiplex single-color real time qPCR and melting curve analysis and provides a straight-forward, rapid, and cost-effective detection method that can identify five Aspergillus species simultaneously in a single reaction using only six unlabeled primers. Due to their unique fragment lengths, the resulting amplicons are directly linked to certain Aspergillus species like fingerprints, following either electrophoresis or melting curve analysis. Our method is characterized by high analytical sensitivity and specificity, so it may serve as a useful and inexpensive tool for Aspergillus diagnostic applications both in health care and the food industry.