Epidemiology of invasive aspergillosis in critically ill patients: clinical presentation, underlying conditions, and outcomes

Evaluation of PERFORMANCE of the IMMY and Dynamiker Aspergillus Galactomannan lateral flow assays for the diagnosis of invasive Aspergillosis

Current laboratory diagnostic techniques for invasive aspergillosis (IA), such as fungal cultures and enzyme immunoassay (EIA) for the galactomannan antigen (GM), are limited by their low sensitivity, labor-intensive nature, and prolonged processing times. Some lateral flow assays (LFAs) have been developed for the diagnosis of IA; however, clinical validation and comparative studies are lacking. This study assessed the diagnostic performance of two CE-marked GM-LFAs, IMMY-GM-LFA and QuicGM-LFA. This retrospective study comprised 44 bronchoalveolar lavage fluid (BALF) and 127 serum samples obtained from 137 patients, 17 (9.9 %) of whom had proven or probable IA categorized using the revised EORTC/MSG criteria, between September 2020 and March 2021. The correlation coefficient between the IMMY-GM-LFA and GM-EIA was 0.95, while that between the QuicGM-LFA and GM-EIA was 0.90. Both LFAs GM indexes were significantly higher among those with proven/probable IA versus those with no IA and possible IA cases (BALF: 7.92 vs 0.18 and 14.05 vs 0.33; serum: 1.86 vs 0.26 and 5.75 vs 0.38 by IMMY and QuicGM-LFA, respectively. All p<0.05). In BALF samples, the area under the curve (AUC) for IMMY-GM-LFA and QuicGM-LFA were 0.93 and 0.96, respectively, with optimized GM cut-offs established at 1.2 for IMMY-GM-LFA and 0.78 for QuicGM-LFA. In serum samples, the AUC for IMMY-GM-LFA was 1.0, and for QuicGM-LFA was 0.9, with optimized cut-offs of 0.7 and 0.76, respectively. In conclusion, this study demonstrated that IMMY-GM and QuicGM-LFAs offer comparable alternatives to the Bio-Rad GM-EIA when testing BALF and serum samples with optimized thresholds.

Role of liposomal amphotericin B in intensive care unit: an expert opinion paper

INTRODUCTION

Invasive fungal infections (IFI) are frequent in patients admitted to the intensive care unit (ICU). The use of first-line antifungals like triazoles or echinocandins may be limited by the global spread of multi-drug resistance species, drug-drug interactions, low organ penetration, and some safety concerns in case of multi-organ failure. Liposomal amphotericin B (L-AmB) is a polyene drug with a broad activity against mold and yeast and an acceptable safety profile. To outline the role of L-AmB in the treatment of IFI in critically ill patients, a panel of experts was invited to draw up an expert opinion paper on the appropriate place in therapy of L-AmB in different clinical scenarios of patients admitted to ICU.

METHODS

A multidisciplinary group of 16 specialists in infectious disease, microbiology, pharmacology, and intensive care elaborated an expert opinion document through a multi-step approach: (1) the scientific panel defined the items and wrote the statements on the management of IFI in ICU, (2) a survey was submitted to an external panel to express agreement or disagreement on the statements, and (3) the panel reviewed the survey and implemented the final document.

RESULTS

The final document included 35 statements that focused on epidemiology and microbiological rationale of the use of systemic L-AmB in critically ill patients and its potential role in specific clinical scenarios in the ICU.

CONCLUSION

Systemic L-AmB may represent an appropriate therapeutic choice for IFI in ICU patients with different underlying conditions, especially when the use of first-line agents is undermined. This expert opinion paper may provide a useful guide for clinicians.

Advances in understanding the role of pentraxin-3 in lung infections

Pentraxin-3 (PTX3) is a soluble pattern recognition molecule (PRM) characterized by a C-terminal pentraxin structural domain and a unique N-terminal structural domain. As a key component of the innate immune system, PTX3 can be rapidly released into the extracellular space during microbial invasion and inflammatory responses. It plays a crucial role in regulating complement activation, enhancing the ability of myeloid cells to recognize pathogens, and exerting various immune effects. PTX3 is integral to the regulation of innate immunity, inflammation, and tumor dynamics through its dual function as both a pro-inflammatory and anti-inflammatory mediator depending on the context. This role is closely linked to its diverse molecular and cellular targets. Additionally, PTX3 has been implicated in the pathogenesis of various lung diseases through its involvement in numerous physiological and pathological processes. In this paper, we summarize the complex immunological functions of PTX3 and review the multifaceted roles it plays in the development of infectious lung diseases. Our objective is to highlight the potential for clinical targeting of PTX3 as a biomarker in infectious diseases and to propose it as a viable alternative in future therapeutic strategies.

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.

Survey of current national and international guidance to reduce risk of aspergillosis in hospitals

Aspergillus spp. are most commonly associated with disease in the severely immunocompromised host and those with chronic chest disease. The scope of patients at risk is expanding, including intensive care (inclusive of severe viral pneumonia), trauma, burns and major surgery. As exposure or colonization is a prerequisite to Aspergillus-related disease, this has prompted a global review of preventative measures recommended in healthcare establishments. This global review includes 75 documents from 24 countries, categorized into clinical, infection prevention and control, and building-related guidance for prevention of invasive aspergillosis (IA). We overview the IA incubation period and different acceptable levels of airborne Aspergilli in protected environments (PEs), including critical care and operating rooms. Few documents cover all aspects of prevention, prophylaxis, avoidance, preventative measures and monitoring (environmental and clinical). A multi-disciplinary approach is required to identify and minimize the multiple risks and ensure adequate preventative measures. Most building-related guidance addresses construction and internal hospital alterations, but we also review the importance of good management of the healthcare environment (including ventilation systems) and uncertainties of environmental monitoring. We highlight the differences in standards recommended for protective patient environments including the critical care environment. The large capital investment required for PEs is often limited to patient groups most at risk. Single document comprehensive guidance is lacking, and many countries provide no guidance. Reduction in healthcare-associated acquisition of invasive aspergillosis during vulnerable inpatient episodes requires heightened awareness of patients at risk, careful risk assessment and attentive maintenance of the general hospital environment.

Superior Sagittal Sinus Thrombosis Secondary to Cerebral Aspergillosis with Ventriculitis in an Immunocompetent Patient: A Case Report

Cerebral aspergillosis is an opportunistic fungal infection that is exceedingly rare in immunocompetent patients. The primary etiological locations for these infections typically involve the nasal cavity and hematological dissemination. A 62-year-old male, focused on wellness, presented with intermittent, nonprogressive headaches in the occipital region, generalized clonic-tonic seizures, and altered consciousness. A computed tomography scan revealed multiple small rim-enhancing lesions in both occipital lobes, with vasogenic edema in both occipital lobes adjacent to the confluence of the sinuses and the posterior superior sagittal sinus. In this case, superior sagittal sinus thrombosis secondary to cerebral aspergillosis was discovered, a condition not previously diagnosed in this specific location but manageable through surgical intervention. A combination of surgical resection and antifungal therapy resulted in favorable outcomes. The prognosis for patients depends significantly on early diagnosis and prompt, aggressive treatment.

Invasive aspergillosis leading to fatal cerebral hemorrhage: a case report and comprehensive literature review

Aspergillus fumigatus significantly threatens immunocompromised individuals by causing potentially fatal diseases, primarily invasive aspergillosis (IA). IA, mostly affecting the lungs, can disseminate to other organs, including the central nervous system (CNS), leading to high mortality rates. We present the case of an 84-year-old immunocompetent male with a history of significant comorbidities, who developed a lethal subarachnoid and tetraventricular hemorrhage. Initial symptoms included paroxysmal neuralgic pain and ophthalmic manifestations. Despite diagnostic efforts, the infection was confirmed only after a positive Aspergillus galactomannan antigen test on cerebrospinal fluid, post-mortem microbiological culture, and mass spectrometry (MS) authentication. The patient exhibited rapid deterioration and succumbed due to the erosion of a mycotic cerebral aneurysm of the left internal carotid artery. Diagnosing IA, particularly isolated CNS IA in immunocompetent patients, is challenging due to its nonspecific symptoms and difficulty detecting the pathogen in standard diagnostic tests. This article emphasizes the pivotal role of pathological examination to obtain a definitive diagnosis, assess fungal infiltration of brain vessels, and thus clarify the accurate source of fatal brain hemorrhages.

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.

Comparison of the Equivalence of Aspergillus Antigen and PCR Results Between Non-Directed Bronchial Lavage and Bronchoalveolar Lavage-A Prospective Exploratory Pilot Study in Critically Ill Patients

BACKGROUND

Obtaining non-directed samples from the upper bronchial tree is easier to perform and poses fewer risks for critically ill patients than deep bronchoalveolar lavage (BAL). Since invasive pulmonary aspergillosis is associated with a high mortality in critically ill patients, timely diagnosis and rapid initiation of treatment are of utmost importance.

OBJECTIVES

The objective of this study was to compare Galactomannan (GM) testing by Enzyme Immunoassay (EIA), GM Lateral Flow Assay (LFA) and the detection of Aspergillus DNA by Polymerase Chain Reaction (PCR) between directed BAL and non-directed bronchial lavage (BL) in critically ill patients.

METHODS

In this prospective, exploratory pilot study, we analysed 120 samples from 40 patients admitted to 12 mixed intensive care units. Inclusion criteria required either risk factors for IPA or positive Aspergillus assessments and met the criteria published by the European Society of Clinical Microbiology and Infectious Diseases guidelines for IPA diagnosis. Both respiratory secretions and blood were collected. In each patient, LFA and PCR were performed on BAL, BL and blood serum, respectively. The EIA test was applied to the BL and BAL of each patient, and the serum of 24 patients. The study was registered on clinicaltrials.gov (NCT04848831).

RESULTS

In a total of 80 respiratory samples, Aspergillus GM EIA yielded optical density indices (ODI) ranging from 0.04 to ≥ 3.5. We observed a high correlation between BAL and BL samples for Aspergillus GM EIA (Pearson's r = 0.78 [95% CI 0.62, 0.88]; intraclass correlation coefficient 0.78). At an ODI cutoff of 0.8 for BAL and 1.2 for BL, the sensitivity of Aspergillus GM EIA was 0.94, while the specificity was 0.67. Increasing the BAL cutoff to 1.0 ODI improved the specificity to 0.86. Aspergillus PCR examination showed good agreement between the two compartments, with a Cohen's kappa coefficient of 0.75 (95% CI 0.48, 1.00). The correlation of Aspergillus GM LFA between BAL and BL was weak.

CONCLUSIONS

Our findings demonstrate that the detection of Aspergillus GM using EIA or Aspergillus PCR in BL is comparable to that in BAL. Thus, BL samples can be reliably used for diagnosing invasive pulmonary aspergillosis.

Invasive aspergillosis in critically ill patients with diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

In the intensive care unit (ICU), invasive aspergillosis (IA) has a poor prognosis. Some studies report a positive association between diabetes mellitus (DM) and IA in critically ill patients, but the relationship between DM and IA in the ICU remains controversial. We aimed to clarify the relationship between DM and IA among patients in the ICU in a systematic review and meta-analysis.

METHODS

We retrieved all reports published in PubMed, EMBASE, and the Cochrane Library databases before July 12, 2023. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the relationship between DM and IA. Subgroup analyses were conducted to further analyze sources of heterogeneity. Heterogeneity was evaluated using the Cochran's Q test and I2 statistic. Additionally, we evaluated publication bias using funnel plots, Egger's test, and Begg's test. Finally, sensitivity analysis was conducted to evaluate the robustness of the results.

RESULTS

Twenty studies with 6155 participants were included in this meta-analysis. We found a positive association between DM and IA among patients in the ICU (OR = 1.18, 95% CI:1.01 to 1.39; p = 0.04). The heterogeneity was not significant (I² = 5%; p = 0.39) and publication bias was not significant (Egger's test: p = 0.654; Begg's test: p = 0.417). The results of sensitivity analysis supported a stable association between DM and IA. Subgroup analysis indicated that patients' comorbidities might be a potential source of heterogeneity. Additionally, patients with DM had a significantly higher risk of COVID-19-associated pulmonary aspergillosis (CAPA) than those without DM (OR = 1.40, 95% CI: 1.15 to 1.70; p < 0.001). The heterogeneity was not significant (I² = 0%; p = 0.91). In the subgroup with influenza, the OR of the relationship between DM and IA was 0.81 (95% CI: 0.54, 1.23; p = 0.32; heterogeneity: p = 0.36; I² = 8%).

CONCLUSIONS

Patients with DM in the ICU showed a higher risk of developing IA than patients in the ICU without DM. DM was a significant risk factor for IA, with the highest risk observed in critically ill patients diagnosed with CAPA.

A Predictive Model for Pulmonary Aspergillosis in ICU Patients: A Multicenter Retrospective Cohort Study

Background

Several predictive models for invasive pulmonary aspergillosis (IPA) based on clinical characteristics have been reported. Nevertheless, the significance of other concurrently detected microorganisms in IPA patients is equally noteworthy. This study aimed to develop a risk prediction model for IPA by integrating clinical and microbiological characteristics.

Methods

This retrospective study was conducted in adult intensive care units (ICUs) of 17 medical centers in China. Clinical data were collected from patients with severe pneumonia who underwent clinical metagenomics of bronchoalveolar lavage fluid between January 1, 2019, and June 30, 2023. Subsequently, patients were randomly assigned to training and validation cohorts in a 7:3 ratio. In the training cohort, potential influencing factors were identified through univariate analysis, clinical practice, and existing literature, and a risk prediction model was constructed using multivariate logistic regression analysis. The performance of this model was then assessed and validated in the validation cohort.

Results

Out of 1737 patients initially included in the study, 898 were ultimately analyzed, of which 100 (11%) were diagnosed with IPA. The risk prediction model for IPA, incorporating microbiological characteristics, identified six independent risk factors, namely age, immunosuppression, chronic kidney disease, connective tissue disease, liver failure, and cytomegalovirus positivity. The model demonstrated a superior discriminative ability, with area under the curve (AUC) values of 0.791 and 0.792 in the training and validation cohorts, respectively. Sensitivity and specificity reached 73.1% and 74.9%, respectively, and the model demonstrated good calibration.

Conclusion

This study developed a novel risk prediction model for IPA incorporating microbiological characteristics based on clinical metagenomics. The model exhibited good discriminative ability and calibration.

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.

Spatiotemporal modeling quantifies cellular contributions to uptake of Aspergillus fumigatus in the human lung

The human lung is confronted daily with thousands of microbial invaders reaching the lower respiratory tract. An efficient response by the resident type 1 and type 2 alveolar epithelial cells (AECs) and alveolar macrophages (AMs) cells during the early hours of innate immunity is a prerequisite to maintain a non-inflammatory state, but foremost to rapidly remove harmful substances. One such human-pathogenic invader is the opportunistic fungus Aspergillus fumigatus. If the spherical conidia are not cleared in time, they swell reaching approximately twice of their initial size and germinate to develop hyphae around six hours post-infection. This process of morphological change is crucial as it enables the pathogen to invade the alveolar epithelium and to reach the bloodstream, but also makes it conspicuous for the immune system. During this process, conidia are first in contact with AECs then with migrating AMs, both attempting to internalize and clear the fungus. However, the relative contribution of AMs and AECs to uptake of A. fumigatus remains an open question, especially the capabilities of the barely investigated type 1 AECs. In this study, we present a bottom-up modeling approach to incorporate experimental data on the dynamic increase of the conidial diameter and A. fumigatus uptake by AECs and AMs in a hybrid agent-based model (hABM) for the to-scale simulation of virtual infection scenarios in the human alveolus. By screening a wide range of parameters, we found that type 1 AECs, which cover approximately 95% of the alveolar surface, are likely to have a greater impact on uptake than type 2 AECs. Moreover, the majority of infection scenarios across the regime of tested parameters were cleared through uptake by AMs, whereas the contribution to conidial uptake by AECs was observed to be limited, indicating that their crucial support might mostly consist in mediating chemokine secretion for AM recruitment. Regardless, as the first host cell being confronted with A. fumigatus conidia, our results evidence the large potential impact of type 1 AECs antimicrobial activities, underlining the requirement of increasing experimental efforts on this alveolar constituent.

Review of the novel antifungal drug olorofim (F901318)

There is clearly a need for novel antifungal agents, not only concerning spectrum, but also oral bioavailability, tolerability, and drug-drug interactions. There is growing concern for antifungal resistance for current available antifungals, mainly driven by environmental fungicide use or long-term exposure to antifungals, in the setting of mould-active prophylaxis or for chronic antifungal infections, such as chronic pulmonary aspergillosis. Moreover, the incidence of breakthrough infections is increasing, because of the introduction of (mould-active) prophylaxis (1-4). There is emergence of difficult to treat invasive fungal infections, such as those caused by Lomentospora prolificans, cryptic species of Aspergillus, Scedosporium and Coccidioides. Olorofim (F901318) is the first-in class of the orotomides, a novel antifungal class targeting dihydroorotate dehydrogenase (DHODH), a key enzyme in the biosynthesis of pyrimidines. Olorofim shows good in vitro and in vivo activity against Aspergillus species, rare and difficult to treat moulds and endemic dimorphic fungi, including azole- and amphotericin-resistant isolates. It lacks activity against yeasts and the Mucorales species. It is only orally available and shows very promising results in ongoing clinical trials. In this review we will describe the mechanism of action of olorofim, the spectrum of activity in vitro and in vivo, pharmacokinetics, pharmacodynamics, drug-drug interactions, resistance, and clinical outcomes.

The Influence of Aspergillus fumigatus Fatty Acid Oxygenases PpoA and PpoC on Caspofungin Susceptibility

Aspergillus fumigatus can cause invasive pulmonary aspergillosis (IPA). Fungicidal azoles and fungistatic caspofungin (CAS) are the first- and second-line therapies, respectively, used to treat IPA. Treatment of A. fumigatus with CAS or micafungin induces the production of the oxylipin 5,8-diHODE by the fungal oxygenase PpoA. For this article, we investigated the influence of ppo genes, which encode the fatty acid oxygenases responsible for oxylipin biosynthesis, on CAS tolerance. The influence of PpoA and PpoC on CAS tolerance is mediated by MpkA phosphorylation and protein kinase A (PKA) activity. RNAseq transcriptional profiling and the label-free quantitative proteomics of the ppoA and ppoC mutants showed that differentially expressed genes and proteins are related to secondary metabolites and carbohydrate metabolism. We also characterized two clinical isolates, CM7555 and IFM61407, which decrease and increase susceptibility to CAS, respectively. CM7555 does not exhibit increased oxylipin production in the presence of CAS but oxylipin induction upon CAS exposure is increased in IFM61407, suggesting that oxylipins are not the only mechanism involved in CAS tolerance in these isolates. Upon CAS exposure, CM7555 has higher MpkA phosphorylation and PKA activity than IFM61407. Our results reveal the different aspects and genetic determinants involved in A. fumigatus CAS tolerance.

Healthcare Costs of Hospitalizations Due to Aspergillosis and 25-Year Trends in Spain, 1997-2021

In the last 40 years, a significant increase in the incidence of lung infections by Aspergillus has been reported. The scarcity of studies that describe the costs of aspergillosis indicates that the economic impact of aspergillosis in the hospital environment is greater than that of other fungal infections. The objective of the study was to evaluate the direct healthcare costs associated with aspergillosis in the Spanish National Health System from 1997 to 2021. A retrospective nationwide longitudinal descriptive study was designed to review hospital records from the Minimum Basic Data Set of patients admitted to hospitals of the National Health System from 1997 to 2021, with a diagnosis of aspergillosis. A total of 44,586 patients were admitted for aspergillosis in the Spanish National Health System. There was a progressive increase in the average annual cost from 1997 to 2012, which reached a maximum peak, EUR 1,395,154.21 (±2,155,192.87). It decreased between 2014 and 2019, but increased again in 2020 and 2021, EUR 28,675.79 (±30,384.12). The Pearson correlation coefficient revealed a weak negative correlation between age and hospital costs and a moderate positive correlation between average length of stay and hospital costs. Our data show that the economic impact of hospitalizations for aspergillosis is significant and increasing at a rate proportionally higher than that of other prevalent diseases. Costs related to Aspergillus infection are associated mainly with respiratory diseases. The results of this economic evaluation may be useful for health authorities to develop a future economic strategy for managing this fungal infection.

Bronchoscopic Diagnosis of Severe Respiratory Infections

The diagnosis of severe respiratory infections in intensive care remains an area of uncertainty and involves a complex balancing of risks and benefits. Due to the frequent colonisation of the lower respiratory tract in mechanically ventilated patients, there is an ever-present possibility of microbiological samples being contaminated by bystander organisms. This, coupled with the frequency of alveolar infiltrates arising from sterile insults, risks over-treatment and antimicrobial-associated harm. The use of bronchoscopic sampling to obtain protected lower respiratory samples has long been advocated to overcome this problem. The use of bronchoscopy further enables accurate cytological assessment of the alveolar space and direct inspection of the proximal airways for signs of fungal infection or alternative pathologies. With a growing range of molecular techniques, including those based on nucleic acid amplification and even alveolar visualisation and direct bacterial detection, the potential for bronchoscopy is increasing concomitantly. Despite this, there remain concerns regarding the safety of the technique and its benefits versus less invasive sampling techniques. These discussions are reflected in the lack of consensus among international guidelines on the topic. This review will consider the benefits and challenges of diagnostic bronchoscopy in the context of severe respiratory infection.

Non-invasive detection of Aspergillosis in ventilated patients: Galactomannan analysis in exhaled breath

This study evaluates the non-invasive diagnosis of Invasive Aspergillosis Pneumonia (IPA) in mechanically ventilated patients by measuring galactomannan (GM) in exhaled breath condensate (EBC). Utilizing a rat model and a novel EBC collection device, we compared GM levels in bronchoalveolar lavage fluid (BALF) and EBC, supplemented by cytokine profiling. Analysis of 75 patients confirmed the device's efficacy, with EBC-GM and BALF-GM showing high diagnostic accuracy (AUC = 0.88). The threshold of 0.235 ng/ml for EBC-GM achieved 92.8 % sensitivity and 66.7 % specificity, with a strong correlation (r = 0.707, P < 0.001) with BALF-GM. This approach offers a safe, effective alternative to invasive diagnostics, enhancing precision with IL-6 and TNF-α measurements. The number registered on clinicaltrails.gov is NCT06333379.

The value of metagenomic next-generation sequencing with different nucleic acid extracting methods of cell-free DNA or whole-cell DNA in the diagnosis of non-neutropenic pulmonary aspergillosis

Purpose

Metagenomic next-generation sequencing(mNGS) is a novel molecular diagnostic technique. For nucleic acid extraction methods, both whole-cell DNA (wcDNA) and cell-free DNA (cfDNA) are widely applied with the sample of bronchoalveolar lavage fluid (BALF). We aim to evaluate the clinical value of mNGS with cfDNA and mNGS with wcDNA for the detection of BALF pathogens in non-neutropenic pulmonary aspergillosis.

Methods

mNGS with BALF-cfDNA, BALF-wcDNA and conventional microbiological tests (CMTs) were performed in suspected non-neutropenic pulmonary aspergillosis. The diagnostic value of different assays for pulmonary aspergillosis was compared.

Results

BALF-mNGS (cfDNA, wcDNA) outperformed CMTs in terms of microorganisms detection. Receiver operating characteristic (ROC) analysis indicated BALF-mNGS (cfDNA, wcDNA) was superior to culture and BALF-GM. Combination diagnosis of either positive for BALF-mNGS (cfDNA, wcDNA) or CMTs is more sensitive than CMTs alone in the diagnosis of pulmonary aspergillosis (BALF-cfDNA+CMTs/BALF-wcDNA+CMTs vs. CMTs: ROC analysis: 0.813 vs.0.66, P=0.0142/0.796 vs.0.66, P=0.0244; Sensitivity: 89.47% vs. 47.37%, P=0.008/84.21% vs. 47.37%, P=0.016). BALF-cfDNA showed a significantly greater reads per million (RPM) than BALF-wcDNA. The area under the ROC curve (AUC) for RPM of Aspergillus detected by BALF-cfDNA, used to predict "True positive" pulmonary aspergillosis patients, was 0.779, with a cut-off value greater than 4.5.

Conclusion

We propose that the incorporation of BALF-mNGS (cfDNA, wcDNA) with CMTs improves diagnostic precision in the identification of non-neutropenic pulmonary aspergillosis when compared to CMTs alone. BALF-cfDNA outperforms BALF-wcDNA in clinical value.

Optimizing Antifungal Treatment Strategies to Prevent Invasive Pulmonary Aspergillosis Infection-Related Deaths in Intensive Care Unit Patients: The Need for Standardization of Research Definitions

The clinical spectrum of invasive pulmonary aspergillosis (IPA) has expanded in recent decades. A large group of patients admitted to intensive care units (ICU) is indeed susceptible to the development of IPA. Although timely diagnosis and antifungal therapy of IPA in this expanding population is crucial to prevent IPA-related deaths, the magnitude of the favorable prognostic impact of antifungal therapy is difficult to measure precisely. In our opinion, the development of standardized research definitions could have favorable implications for further improving our ability both to measure the favorable effect of antifungal treatment and to prevent IPA-related death in ICU patients.

Global incidence and mortality of severe fungal disease

Current estimates of fungal disease incidence and mortality are imprecise. Population at risk denominators were used to estimate annual incidence for 2019-21. Extensive literature searches from 2010 to 2023 were combined with over 85 papers on individual country and global disease burden. Crude and attributable mortality were estimated using a combination of untreated mortality, the proportion of patients who are treated, and percentage survival in treated patients. Awareness, guidelines, and accessibility of diagnostics and therapies informed the ratio of treated to untreated cases. Estimates do not include influenza or COVID-19 outbreaks. Data from more than 120 countries were included. Annually, over 2 113 000 people develop invasive aspergillosis in the context of chronic obstructive pulmonary disease, intensive care, lung cancer, or haematological malignancy, with a crude annual mortality of 1 801 000 (85·2%). The annual incidence of chronic pulmonary aspergillosis is 1 837 272, with 340 000 (18·5%) deaths. About 1 565 000 people have a Candida bloodstream infection or invasive candidiasis each year, with 995 000 deaths (63·6%). Pneumocystis pneumonia affects 505 000 people, with 214 000 deaths (42·4%). Cryptococcal meningitis affects 194 000 people, with 147 000 deaths (75·8%). Other major life-threatening fungal infections affect about 300 000 people, causing 161 000 deaths (53·7%). Fungal asthma affects approximately 11·5 million people and might contribute to 46 000 asthma deaths annually. These updated estimates suggest an annual incidence of 6·5 million invasive fungal infections and 3·8 million deaths, of which about 2·5 million (68%; range 35-90) were directly attributable.

Aspergillosis in Critically Ill Patients with and Without COVID-19 in a Tertiary Hospital in Southern Brazil

The impact of invasive pulmonary aspergillosis (IPA) on non-neutropenic critically ill patients in intensive care units (ICU) has been demonstrated in recent decades. Furthermore, after the start of the COVID-19 pandemic, COVID-19 associated with pulmonary aspergillosis (CAPA) has become a major concern in ICUs. However, epidemiological data from different regions are scarce. We evaluated the prevalence and clinical-epidemiological data of IPA in patients with COVID-19 requiring mechanical ventilation (MV) in the ICU ("severe COVID-19") and non-COVID ICU patients in MV of a tertiary hospital in the southern region of Brazil. Eighty-seven patients admitted between June 2020 and August 2022 were included; 31 with severe COVID-19. For the diagnosis of IPA or CAPA, algorithms including host factors and mycological criteria (positive culture for Aspergillus spp., immunoassay for galactomannan detection, and/or qPCR) were utilized. The overall incidence of IPA and CAPA in our ICU was 73 cases/1000 ICU hospitalizations. Aspergillosis occurred in 13% (4/31) of the COVID-19 patients, and in 16% (9/56) of the critically ill patients without COVID-19, with mortality rates of 75% (3/4) and 67% (6/9), respectively. Our results highlight the need for physicians enrolled in ICU care to be aware of aspergillosis and for more access of the patients to sensitive and robust diagnostic tests by biomarkers detection.

INTERPRETABLE MACHINE LEARNING FOR PREDICTING RISK OF INVASIVE FUNGAL INFECTION IN CRITICALLY ILL PATIENTS IN THE INTENSIVE CARE UNIT: A RETROSPECTIVE COHORT STUDY BASED ON MIMIC-IV DATABASE

ABSTRACT

The delayed diagnosis of invasive fungal infection (IFI) is highly correlated with poor prognosis in patients. Early identification of high-risk patients with invasive fungal infections and timely implementation of targeted measures is beneficial for patients. The objective of this study was to develop a machine learning-based predictive model for invasive fungal infection in patients during their intensive care unit (ICU) stay. Retrospective data was extracted from adult patients in the MIMIC-IV database who spent a minimum of 48 h in the ICU. Feature selection was performed using LASSO regression, and the dataset was balanced using the BL-SMOTE approach. Predictive models were built using six machine learning algorithms. The Shapley additive explanation algorithm was used to assess the impact of various clinical features in the optimal model, enhancing interpretability. The study included 26,346 ICU patients, of whom 379 (1.44%) were diagnosed with invasive fungal infection. The predictive model was developed using 20 risk factors, and the dataset was balanced using the borderline-SMOTE (BL-SMOTE) algorithm. The BL-SMOTE random forest model demonstrated the highest predictive performance (area under curve = 0.88, 95% CI = 0.84-0.91). Shapley additive explanation analysis revealed that the three most influential clinical features in the BL-SMOTE random forest model were dialysis treatment, APSIII scores, and liver disease. The machine learning model provides a reliable tool for predicting the occurrence of IFI in ICU patients. The BL-SMOTE random forest model, based on 20 risk factors, exhibited superior predictive performance and can assist clinicians in early assessment of IFI occurrence in ICU patients. Importance: Invasive fungal infections are characterized by high incidence and high mortality rates characteristics. In this study, we developed a clinical prediction model for invasive fungal infections in critically ill patients based on machine learning algorithms. The results show that the machine learning model based on 20 clinical features has good predictive value.

Invasive pulmonary aspergillosis among patients with severe community-acquired pneumonia and influenza in ICUs: a retrospective cohort study

RATIONALE

The prevalence, clinical characteristics, and outcomes of invasive pulmonary aspergillosis in patients with severe community-acquired pneumonia (CAP) in intensive care units remain underestimated because of the lack of a disease-recognition scheme and the inadequacy of diagnostic tests.

OBJECTIVES

To identify the prevalence, risk factors, and outcomes of severe CAP complicated with invasive pulmonary aspergillosis (IPA) in intensive care units (ICUs).

METHODS

We conducted a retrospective cohort study including recruited 311 ICU-hospitalized patients with severe CAP without influenza or with influenza. Bronchoalveolar lavage fluid (BALF) samples were from all patients and subjected to mycological testing. Patients were categorized as having proven or probable Aspergillus infection using a modified form of the AspICU algorithm comprising clinical, radiological, and mycological criteria.

MEASUREMENTS AND MAIN RESULTS

Of the 252 patients with severe CAP and 59 influenza patients evaluated, 24 met the diagnostic criteria for proven or probable Aspergillus infection in the CAP group and 9 patients in the influenza group, giving estimated prevalence values of 9.5% and 15.3%, respectively. COPD and the use of inhaled corticosteroids were independent risk factors for IPA. IPA in patients with severe CAP was significantly associated with the duration of mechanical support, the length of ICU stay, and the 28-day mortality.

CONCLUSIONS

An aggressive diagnostic approach for IPA patients with severe CAP and not only influenza or COVID-19 should be pursued. Further randomized controlled trials need to evaluate the timing, safety, and efficacy of antifungal therapy in reducing IPA incidence and improving clinical outcomes.

Therapeutic Drug Monitoring and Biomarkers; towards Better Dosing of Antimicrobial Therapy

Due to variability in pharmacokinetics and pharmacodynamics, clinical outcomes of antimicrobial drug therapy vary between patients. As such, personalised medication management, considering both pharmacokinetics and pharmacodynamics, is a growing concept of interest in the field of infectious diseases. Therapeutic drug monitoring is used to adjust and individualise drug regimens until predefined pharmacokinetic exposure targets are achieved. Minimum inhibitory concentration (drug susceptibility) is the best available pharmacodynamic parameter but is associated with many limitations. Identification of other pharmacodynamic parameters is necessary. Repurposing diagnostic biomarkers as pharmacodynamic parameters to evaluate treatment response is attractive. When combined with therapeutic drug monitoring, it could facilitate making more informed dosing decisions. We believe the approach has potential and justifies further research.

Invasive Fungal Diseases in Adult Patients in Intensive Care Unit (FUNDICU): 2024 consensus definitions from ESGCIP, EFISG, ESICM, ECMM, MSGERC, ISAC, and ISHAM

PURPOSE

The aim of this document was to develop standardized research definitions of invasive fungal diseases (IFD) in non-neutropenic, adult patients without classical host factors for IFD, admitted to intensive care units (ICUs).

METHODS

After a systematic assessment of the diagnostic performance for IFD in the target population of already existing definitions and laboratory tests, consensus definitions were developed by a panel of experts using the RAND/UCLA appropriateness method.

RESULTS

Standardized research definitions were developed for proven invasive candidiasis, probable deep-seated candidiasis, proven invasive aspergillosis, probable invasive pulmonary aspergillosis, and probable tracheobronchial aspergillosis. The limited evidence on the performance of existing definitions and laboratory tests for the diagnosis of IFD other than candidiasis and aspergillosis precluded the development of dedicated definitions, at least pending further data. The standardized definitions provided in the present document are aimed to speed-up the design, and increase the feasibility, of future comparative research studies.

Distribution of Aspergillus species and prevalence of azole resistance in clinical and environmental samples from a Spanish hospital during a three-year study period

BACKGROUND

Surveillance studies are crucial for updating trends in Aspergillus species and antifungal susceptibility information.

OBJECTIVES

Determine the Aspergillus species distribution and azole resistance prevalence during this 3-year prospective surveillance study in a Spanish hospital.

MATERIALS AND METHODS

Three hundred thirty-five Aspergillus spp. clinical and environmental isolates were collected during a 3-year study. All isolates were screened for azole resistance using an agar-based screening method and resistance was confirmed by EUCAST antifungal susceptibility testing. The azole resistance mechanism was confirmed by sequencing the cyp51A gene and its promoter. All Aspergillus fumigatus strains were genotyped using TRESPERG analysis.

RESULTS

Aspergillus fumigatus was the predominant species recovered with a total of 174 strains (51.94%). The rest of Aspergillus spp. were less frequent: Aspergillus niger (14.93%), Aspergillus terreus (9.55%), Aspergillus flavus (8.36%), Aspergillus nidulans (5.37%) and Aspergillus lentulus (3.28%), among other Aspergillus species (6.57%). TRESPERG analysis showed 99 different genotypes, with 72.73% of the strains being represented as a single genotype. Some genotypes were common among clinical and environmental A. fumigatus azole-susceptible strains, even when isolated months apart. We describe the occurrence of two azole-resistant A. fumigatus strains, one clinical and another environmental, that were genotypically different and did not share genotypes with any of the azole-susceptible strains.

CONCLUSIONS

Aspergillus fumigatus strains showed a very diverse population although several genotypes were shared among clinical and environmental strains. The isolation of azole-resistant strains from both settings suggest that an efficient analysis of clinical and environmental sources must be done to detect azole resistance in A. fumigatus.

Viral Pneumonia: From Influenza to COVID-19

Respiratory viruses are increasingly recognized as a cause of community-acquired pneumonia (CAP). The implementation of new diagnostic technologies has facilitated their identification, especially in vulnerable population such as immunocompromised and elderly patients and those with severe cases of pneumonia. In terms of severity and outcomes, viral pneumonia caused by influenza viruses appears similar to that caused by non-influenza viruses. Although several respiratory viruses may cause CAP, antiviral therapy is available only in cases of CAP caused by influenza virus or respiratory syncytial virus. Currently, evidence-based supportive care is key to managing severe viral pneumonia. We discuss the evidence surrounding epidemiology, diagnosis, management, treatment, and prevention of viral pneumonia.

Comparison of influenza- and COVID-19-associated pulmonary aspergillosis in China

PURPOSE

We conducted a monocentric retrospective study using the latest definitions to compare the demographic, clinical, and biological characteristics of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA).

METHODS

The study retrospectively enrolled 180 patients, including 70 influenza/IPA patients (with positive influenza A/B and Aspergillus) and 110 COVID-19/IPA patients (with positive SARS-CoV-2 and Aspergillus). Among them, 42 (60%) and 30 (27.3%) patients fulfilled the definitions of IAPA and CAPA, respectively.

RESULTS

The CAPA patients had significantly higher in-hospital mortality (13/31, 41.9%) than IAPA patients (8/42, 19%) with a P-value of 0.033. Kaplan-Meier survival curve also showed significantly higher 30-day mortality for CAPA patients (P = 0.025). Additionally, the CAPA patients were older, though insignificantly, than IAPA patients (70 (60-80) vs. 62 (52-72), P = 0.075). A lower percentage of chronic pulmonary disease (12.9 vs. 40.5%, P = 0.01) but higher corticosteroids use 7 days before and after ICU admission (22.6% vs. 0%, P = 0.002) were found in CAPA patients. Notably, there were no significant differences in the percentage of ICU admission or ICU mortality between the two groups. In addition, the time from observation to Aspergillus diagnosis was significantly longer in CAPA patients than in IAPA patients (7 (2-13) vs. 0 (0-4.5), P = 0.048).

CONCLUSION

Patients infected with SARS-CoV-2 and Aspergillus during the concentrated outbreak of COVID-19 in China had generally higher in-hospital mortality but a lower percentage of chronic pulmonary disease than those infected with influenza and Aspergillus. For influenza-infected patients who require hospitalization, close attention should be paid to the risk of invasive aspergillosis upfront.

Diagnosis and management of invasive fungal diseases in non-neutropenic ICU patients, with focus on candidiasis and aspergillosis: a comprehensive review

Invasive fungal diseases pose a significant threat to non-neutropenic ICU patients, with Candida and Aspergillus infections being the most common. However, diagnosing these infections in the ICU population remains challenging due to overlapping clinical features, poor sensitivity of blood cultures, and invasive sampling requirements. The classical host criteria for defining invasive fungal disease do not fully apply to ICU patients, leading to missed or delayed diagnoses. Recent advancements have improved our understanding of invasive fungal diseases, leading to revised definitions and diagnostic criteria. However, the diagnostic difficulties in ICU patients remain unresolved, highlighting the need for further research and evidence generation. Invasive candidiasis is the most prevalent form of invasive fungal disease in non-neutropenic ICU patients, presenting as candidemia and deep-seated candidiasis. Diagnosis relies on positive blood cultures or histopathology, while non-culture-based techniques such as beta-D-glucan assay and PCR-based tests show promise. Invasive aspergillosis predominantly manifests as invasive pulmonary aspergillosis in ICU patients, often associated with comorbidities and respiratory deterioration in viral pneumonia. Diagnosis remains challenging due to poor sensitivity of blood cultures and difficulties in performing lung biopsies. Various diagnostic criteria have been proposed, including mycological evidence, clinical/radiological factors and expanded list of host factors. Non-culture-based techniques such as galactomannan assay and PCR-based tests can aid in diagnosis. Antifungal management involves tailored therapy based on guidelines and individual patient factors. The complexity of diagnosing and managing invasive fungal diseases in ICU patients underscore the importance of ongoing research and the need for updated diagnostic criteria and treatment approaches. Invasive fungal disease, Invasive fungal infection, Invasive candidiasis, Invasive aspergillosis, Antifungal drugs.

Prognostic factors and outcomes of invasive pulmonary aspergillosis, a retrospective hospital-based study

Objective

Invasive pulmonary aspergillosis (IPA) affects immunocompromised hosts and is associated with higher risks of respiratory failure and mortality. However, the clinical outcomes of different IPA types have not been identified.

Methods

Between September 2002 and May 2021, we retrospectively enrolled patients with IPA in Taichung Veterans General Hospital, Taiwan. Cases were classified as possible IPA, probable IPA, proven IPA, and putative IPA according to EORTC/MSGERC criteria and the AspICU algorithm. Risk factors of respiratory failure, kidney failure, and mortality were analyzed by logistic regression. A total of 3-year survival was assessed by the Kaplan-Meier method with log-rank test for post-hoc comparisons.

Results

We included 125 IPA patients (50: possible IPA, 47: probable IPA, 11: proven IPA, and 17: putative IPA). Comorbidities of liver cirrhosis and solid organ malignancy were risk factors for respiratory failure; diabetes mellitus and post-liver or kidney transplantation were related to kidney failure. Higher galactomannan (GM) test optical density index (ODI) in either serum or bronchoalveolar lavage fluid was associated with dismal outcomes. Probable IPA and putative IPA had lower 3-year respiratory failure-free survival compared to possible IPA. Probable IPA and putative IPA exhibited lower 3-year renal failure-free survival in comparison to possible IPA and proven IPA. Putative IPA had the lowest 3-year overall survival rates among the four IPA groups.

Conclusion

Patients with putative IPA had higher mortality rates than the possible, probable, or proven IPA groups. Therefore, a prompt diagnosis and timely treatment are warranted for patients with putative IPA.

Age difference of patients with and without invasive aspergillosis: a systematic review and meta-analysis

BACKGROUND

Invasive Aspergillosis (IA) is a life-threatening fungal disease with significant mortality rates. Timely diagnosis and treatment greatly enhance patient outcomes. This study aimed to explore the association between patient age and the development of IA, as well as the potential implications for risk stratification strategies.

METHODS

We searched National Center for Biotechnology Information (NCBI) databases for publications until October 2023 containing age characteristics of patients with and without IA. A random-effects model with the application of inverse-variance weighting was used to pool reported estimates from each study, and meta-regression and subgroup analyses were utilized to assess sources of heterogeneity.

RESULTS

A systematic review was conducted, resulting in the inclusion of 55 retrospective observational studies with a total of 13,983 patients. Meta-analysis revealed that, on average, patients with IA were approximately two and a half years older (95% Confidence Interval [CI] 1.84-3.31 years; I2 = 26.1%) than those without the disease (p < 0.0001). No significant moderators could explain the observed heterogeneity in age difference. However, subgroup analysis revealed that age differences were more pronounced within particular patient groups compared to others. For example, patients with and without IA who had primary severe lung infections exhibited a greater difference in mean age than other patient cohorts.

CONCLUSIONS

Further research, such as individual patient data meta-analysis, is necessary to better understand the potential relationship between increasing age and the likelihood of IA. Improved risk stratification strategies based on patient age could potentially enhance the early detection and treatment of IA, ultimately improving patient outcomes.

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.

Incidence and inhospital outcomes of coronavirus disease 2019-associated pulmonary aspergillosis in the United States

OBJECTIVE

The aim of this study was to estimate the predictors, associations, and outcomes of COVID-19-associated pulmonary disease (CAPA) in the United States.

STUDY DESIGN AND METHODS

This retrospective cohort study was performed by using the National Inpatient Sample Database 2020 to identify coronavirus disease 2019 (COVID-19) and CAPA hospitalizations. Baseline variables and outcomes were compared between COVID-19 hospitalizations without aspergillosis and those with aspergillosis. These variables were then used to perform an adjusted analysis for obtaining predictors and factors associated with CAPA and its inhospital mortality.

RESULTS

Of the 1,020,880 hospitalizations identified with the principal diagnosis of COVID-19, CAPA was identified in 1510 (0.1%) hospitalizations. The CAPA cohort consisted of a higher proportion of males (58%) as well as racial and ethnic minorities (Hispanics, Blacks, and others [including Asian or Pacific islanders, native Americans]). Inhospital mortality was significantly higher (47.35% vs. 10.87%, P < 0.001), the average length of stay was longer (27.61 vs. 7.29 days, P < 0.001), and the mean cost per hospitalization was higher ($121,560 vs. $18,423, P < 0.001) in the CAPA group compared to COVID-19 without aspergillosis. History of solid organ transplant, chronic obstructive pulmonary disease, and venous thromboembolism were associated with higher odds of CAPA among other factors. The use of invasive mechanical ventilation (adjusted odds ratio [aOR] 6.24, P < 0.001), acute kidney injury (aOR 2.02, P = 0.028), and septic shock (aOR 2.07, P = 0.018) were associated with higher inhospital mortality in the CAPA cohort.

CONCLUSION

While CAPA is an infrequent complication during hospitalizations for COVID-19, it significantly increases all-cause mortality, prolongs hospital stays, and leads to higher hospital expenses compared to COVID-19 cases without aspergillosis.

Posaconazole exposure in critically ill ICU patients: a need for action

PURPOSE

Posaconazole is an antifungal drug currently being used for prophylaxis and treatment of invasive fungal infections such as aspergillosis. To date, therapeutic drug monitoring (TDM) of posaconazole is recommended with the use of oral suspension, but the potential need of TDM with the use of IV formulations is rising. Therefore, we aimed to investigate the pharmacokinetics of IV posaconazole in critically ill patients.

METHODS

In a prospective study, we analysed 168 consecutivelly collected posaconazole levels from 10 critically ill patients drawn during a 7 day curse. Posaconazole concentrations were measured using a chromatographic method. Demographic and laboratory data were collected, and the data was analysed using descriptive statistics.

RESULTS

We included 168 posaconazole levels, resulting in a median trough of 0.62 [0.29-1.05] mg/L with 58% not reaching the suggested target of 0.5 mg/L for fungal prophylaxis. Moreover, 74% of the trough levels were under the target of 1 mg/L which is proposed for the treatment of aspergillosis.

CONCLUSION

Posaconazole exposure is highly variable in critically ill patients resulting in potentially insufficient drug concentrations in many cases. TDM is highly recommended to identify and avoid underexposure.

TRIAL REGISTRATION NUMBER

NCT05275179, March 11, 2022.

Pathogenicity and virulence of Aspergillus fumigatus

Pulmonary infections caused by the mould pathogen Aspergillus fumigatus are a major cause of morbidity and mortality globally. Compromised lung defences arising from immunosuppression, chronic respiratory conditions or more recently, concomitant viral or bacterial pulmonary infections are recognised risks factors for the development of pulmonary aspergillosis. In this review, we will summarise our current knowledge of the mechanistic basis of pulmonary aspergillosis with a focus on emerging at-risk populations.

Prediction of pulmonary aspergillosis in patients with ventilator-associated pneumonia

BACKGROUND

Predictors of ICU-acquired pulmonary aspergillosis (IPA) are not well-established in critically ill patients with ventilator-associated pneumonia (VAP), making IPA commonly misdiagnosed and anti-fungal therapy delayed. We aimed to develop a clinical score for prediction of IPA among patients with VAP.

METHODS

Mechanically ventilated patients who developed VAP in 4 ICUs in Bretagne, Western France, were included. The score was constructed in a learning cohort, based on predictors of IPA in logistic regression model, and validated in a validation cohort.

RESULTS

Among 1636 mechanically ventilated patients, 215 developed VAP but only 39 developed IPA (4 possible and 35 probable/putative) (18%). Most cases (31/39) were documented through a positive broncho-alveolar sample culture. Independent predictors of IPA were immunodepression (including onco-hematological disorder, immunomodulatory treatment, solid organ transplant, neutropenia < 0.5G/L and high-dose steroids ≥ 1 mg/kg/day of prednisolone equivalent) (p = 0.001; score = 1 point) and lymphocyte count at admission < 0.8 G/L (p = 0.019; score = 1 point). Operational values of the predictive score in the learning/validation cohort were 50%/52% sensitivity and 90%/87% specificity, respectively, for high PiPa score (score = 2) and 94%/91% sensitivity and 44%/46% specificity, respectively, for moderate PiPa score (score = 1). Finally, the AUC for the prediction of IPA was 0.783 in the learning cohort and 0.770 in the validation cohort.

CONCLUSIONS

We evaluated a clinical score with good predictive value which may help to predict IPA in patient with VAP. External validation will be needed to confirm our preliminary findings.

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

The prevalence of invasive pulmonary aspergillosis (IPA) is growing in critically ill patients in the intensive care unit (ICU). It is increasingly recognized in immunocompetent hosts and immunocompromised ones. IPA frequently complicates both severe influenza and severe coronavirus disease 2019 (COVID-19) infection. It continues to represent both a diagnostic and therapeutic challenge and can be associated with significant morbidity and mortality. In this narrative review, we describe the epidemiology, risk factors and disease manifestations of IPA. We discuss the latest evidence and current published guidelines for the diagnosis and management of IPA in the context of the critically ill within the ICU. Finally, we review influenza-associated pulmonary aspergillosis (IAPA), COVID-19-associated pulmonary aspergillosis (CAPA) as well as ongoing and future areas of research.

Invasive pulmonary aspergillosis in the ICU: tale of a broadening risk profile

PURPOSE OF REVIEW

In the absence of histopathological proof, the diagnosis of invasive pulmonary aspergillosis (IPA) is usually based on mycology (not on tissue), medical imaging, and the patient's risk profile for acquiring invasive fungal disease. Here, we review the changes in risk profile for IPA that took place over the past decades.

RECENT FINDINGS

In the early 2000s IPA was considered exclusively a disease of immunocompromised patients. Particularly in the context of critical illness, the risk profile has been broadened steadily. Acute viral infection by influenza or SARS-Cov-2 are now well recognized risk factors for IPA.

SUMMARY

The classic risk profile ('host factors') reflecting an immunocompromised status was first enlarged by a spectrum of chronic conditions such as AIDS, cirrhosis, and chronic obstructive pulmonary disease. In the presence of critical illness, especially characterized by sepsis and/or severe respiratory distress, any chronic condition could add to the risk profile. Recently, acute viral infections have been associated with IPA leading to the concepts of influenza-associated IPA and COVID-19-associated IPA. These viral infections may affect patients without underlying disease. Hence, the risk for IPA is now a reality for ICU patients, even in the absence of any chronic conditions.

The Clinical Significance of Aspergillus Detected in Lower-Respiratory-Tract Samples of Critically Ill COVID-19-Positive Patients

Objective: Critically ill patients with acute respiratory distress syndrome (ARDS) due to viral infection are at risk for secondary complications, including invasive aspergillosis. Our study aimed to characterize the clinical significance and outcome of Aspergillus species isolated from lower-respiratory-tract samples of critically ill OVID-19 patients at a single center. Design: We conducted a retrospective cohort study to evaluate the characteristics of patients with COVID-19 and aspergillus isolated from the lower respiratory tract and to identify predictors of outcomes in this population. Setting: The setting was a single-center hospital system within the metropolitan Detroit region. Results: The prevalence of Aspergillus isolated in hospitalized COVID-19 patients was 1.18% (30/2461 patients), and it was 4.6% in critically ill ICU patients with COVID-19. Probable COVID-19-associated invasive pulmonary aspergillosis (CAPA) was found in 21 critically ill patients, and 9 cases were classified as colonization. The in-hospital mortality of critically ill patients with CAPA and those with aspergillus colonization were high but not significantly different (76% vs. 67%, p = 1.00). Furthermore, the in-hospital mortality for ICU patients with or without Aspergillus isolated was not significantly different 73.3% vs. 64.5%, respectively (OR 1.53, CI 0.64-4.06, p = 0.43). In patients in whom Aspergillus was isolated, antifungal therapy (p = 0.035, OR 12.3, CI 1.74-252); vasopressors (0.016, OR 10.6, CI 1.75-81.8); and a higher mSOFA score (p = 0.043, OR 1.29 CI 1.03-1.72) were associated with a worse outcome. In a multivariable model adjusting for other significant variables, FiO2 was the only variable associated with in-hospital mortality in patients in whom Aspergillus was isolated (OR 1.07, 95% CI 1.01-1.27). Conclusions: The isolation of Aspergillus from lower-respiratory-tract samples of critically ill patients with COVID-19 is associated with high mortality. It is important to have a low threshold for superimposed infections such as CAPA in critically ill patients with COVID-19.

A score for predicting invasive pulmonary aspergillosis in immunocompetent critically ill patients

BACKGROUND

Delayed treatment leads to increased mortality in critically ill patients with invasive pulmonary aspergillosis (IPA). We aimed to develop and validate a prediction score based on novel biomarkers and clinical risk factors to identify IPA in immunocompetent patients in the intensive care unit (ICU).

METHODS

A retrospective study was conducted to collect medical information and novel biomarkers upon ICU admission. Risk factors adopted for the final prediction score were identified using multivariate logistic regression analysis.

RESULTS

We retrospectively collected 1841 critical ill patients between January 2018 and August 2022. Patients with IPA had higher C-reactive protein-to-albumin ratio (CAR), neutrophil-to-lymphocyte ratio, systemic immune-inflammation index and lower prognostic nutritional index (PNI). Chronic obstructive pulmonary disease (COPD), continuous renal replacement therapy (CRRT), high dose of corticosteroids, broad-spectrum antibiotics, blood galactomannan (GM) positivity and high CAR were independent risk factors for IPA and were entered into the final prediction score. The score had good discrimination, with the area under receiver operating characteristic curve of 0.816 and 0.780 for the training and validation cohorts, respectively, and good calibration.

CONCLUSION

A score based on six clinical and novel immunological biomarkers showed promising predictive value for antifungal treatment in immunocompetent ICU patients.

Mortality in ICU Patients with COVID-19-Associated Pulmonary Aspergillosis

A review of 38 studies involving 1437 COVID-19 patients admitted to intensive care units (ICUs) with pulmonary aspergillosis (CAPA) was conducted to investigate whether mortality has improved since the pandemic's onset. The study found that the median ICU mortality was 56.8%, ranging from 30% to 91.8%. These rates were higher for patients admitted during 2020-2021 (61.4%) compared to 2020 (52.3%), and prospective studies found higher ICU mortality (64.7%) than retrospective ones (56.4%). The studies were conducted in various countries and used different criteria to define CAPA. The percentage of patients who received antifungal therapy varied across studies. These results indicate that the mortality rate among CAPA patients is a growing concern, mainly since there has been an overall reduction in mortality among COVID-19 patients. Urgent action is needed to improve prevention and management strategies for CAPA, and additional research is needed to identify optimal treatment strategies to reduce mortality rates among these patients. This study serves as a call to action for healthcare professionals and policymakers to prioritize CAPA, a serious and potentially life-threatening complication of COVID-19.

Phenotypic Array for Identification and Screening of Antifungals against Aspergillus Isolates from Respiratory Infections in KwaZulu Natal, South Africa

The rapid emergence of invasive fungal infections correlates with the increasing population of immunocompromised individuals, with many cases leading to death. The progressive increase in the incidence of Aspergillus isolates is even more severe due to the clinical challenges in treating invasive infections in immunocompromised patients with respiratory conditions. Rapid detection and diagnosis are needed to reduce mortality in individuals with invasive aspergillosis-related infections and thus efficient identification impacts clinical success. The phenotypic array method was compared to conventional morphology and molecular identification on thirty-six Aspergillus species isolated from patients with respiratory infections at the Inkosi Albert Luthuli Hospital in Kwa-Zulu Natal. In addition, an antimicrobial array was also carried out to screen for possible novel antimicrobial compounds for treatment. Although traditional morphological techniques are useful, genetic identification was the most reliable, assigning 26 to Aspergillus fumigatus species, 8 Aspergillus niger, and 2 Aspergillus flavus including cryptic species of A. niger, A. tubingensis and A. welwitschiae. The phenotypic array technique was only able to identify isolates up to the genus level due to a lack of adequate reference clinical species in the database. However, this technique proved crucial in assessing a wide range of possible antimicrobial options after these isolates exhibited some resistance to azoles. Antifungal profiles of the thirty-six isolates on the routine azole voriconazole showed a resistance of 6%, with 61% having moderate susceptibility. All isolates resistant to the salvage therapy drug, posaconazole pose a serious concern. Significantly, A. niger was the only species resistant (25%) to voriconazole and has recently been reported as the species isolated from patients with COVID-19-associated pulmonary aspergillosis (CAPA). Phenotypic microarray showed that 83% of the isolates were susceptible to the 24 new compounds and novel compounds were identified for potentially effective combination treatment of fungal infections. This study also reports the first TR34/98 mutation in Aspergillus clinical isolates which is located in the cyp51A gene.

A Comparison of Diagnostic Criteria for Invasive Pulmonary Aspergillosis in Critically Ill Patients

INTRODUCTION

Invasive pulmonary aspergillosis (IPA) is a common infection in intensive care units (ICUs). There are no consensus criteria for defining IPA in the ICU. We aimed to compare the diagnosis and prognosis performances of three criteria (the 2020 EORTC/MSG criteria, the 2021 EORTC/MSG ICU criteria, the modified AspICU criteria (M-AspICU)) for IPA in the ICU.

METHODS

In this retrospective study from our single center, we applied the three different criteria for IPA in patients with suspected pneumonia and undergoing at least one mycological test between November 10, 2016 and November 10, 2021. We compared the diagnosis agreement and prognosis performances of these three criteria in the ICU.

RESULTS

Overall, 2403 patients were included. The rates of IPA according to the 2020 EORTC/MSG, 2021 EORTC/MSG ICU, and M-AspICU were 3.37%, 6.53%, and 23.10%, respectively. Diagnostic agreement among these criteria was poor (Cohen's kappa 0.208-0.666). IPA diagnosed by either the 2020 EORTC/MSG (odds ratio = 2.709, P < 0.001) or the 2021 EORTC/MSG ICU (odds ratio = 2.086, P = 0.001) criteria was independently associated with 28-day mortality. IPA diagnosed by M-AspICU is an independent risk factor of 28-day mortality (odds ratio = 1.431, P = 0.031) when excluding patients who fulfilled neither host criteria nor radiological factors of 2021 EORTC/MSG ICU.

CONCLUSIONS

Although M-AspICU criteria have the highest "sensitivity", IPA diagnosed by M-AspICU was not an independent risk factor of 28-day mortality. Caution is required when using the M-AspICU criteria in ICU, especially in patients with non-specific infiltration and non-classical host factors.

Mutations in the Second Alternative Oxidase Gene: A New Approach to Group Aspergillus niger Strains

Alternative oxidase is a terminal oxidase in the branched mitochondrial electron transport chain of most fungi including Aspergillus niger (subgenus Circumdati, section Nigri). A second, paralogous aox gene (aoxB) is extant in some A. niger isolates but also present in two divergent species of the subgenus Nidulantes-A. calidoustus and A. implicatus-as well as in Penicillium swiecickii. Black aspergilli are cosmopolitan opportunistic fungi that can cause diverse mycoses and acute aspergillosis in immunocompromised individuals. Amongst the approximately 75 genome-sequenced A. niger strains, aoxB features considerable sequence variation. Five mutations were identified that rationally affect transcription or function or terminally modify the gene product. One mutant allele that occurs in CBS 513.88 and A. niger neotype strain CBS 554.65 involves a chromosomal deletion that removes exon 1 and intron 1 from aoxB. Another aoxB allele results from retrotransposon integration. Three other alleles result from point mutations: a missense mutation of the start codon, a frameshift, and a nonsense mutation. A. niger strain ATCC 1015 has a full-length aoxB gene. The A. niger sensu stricto complex can thus be subdivided into six taxa according to extant aoxB allele, which may facilitate rapid and accurate identification of individual species.

Impact of Invasive Pulmonary Aspergillosis in Critically Ill Surgical Patients with or without Solid Organ Transplantation

BACKGROUND

Critically ill patients, especially those who have undergone solid organ transplantation (SOT), are at risk of invasive pulmonary aspergillosis (IPA). The outcome relevance of adequately treated putative IPA (pIPA) is a matter of debate. The aim of this study is to assess the outcome relevance of pIPA in a cohort of critically ill patients with and without SOT.

METHODS

Data from 121 surgical critically ill patients with pIPA (n = 30) or non-pIPA (n = 91) were included. Cox regression analysis was used to identify risk factors for mortality and unfavourable outcomes after 28 and 90 days.

RESULTS

Mortality rates at 28 days were similar across the whole cohort of patients (pIPA: 31% vs. non-pIPA: 27%) and did not differ in the subgroup of patients after SOT (pIPA: 17% vs. non-pIPA: 22%). A higher Sequential Organ Failure Assessment (SOFA) score and evidence of bacteraemia were identified as risk factors for mortality and unfavourable outcome, whereas pIPA itself was not identified as an independent predictor for poor outcomes.

CONCLUSIONS

Adequately treated pIPA did not increase the risk of death or an unfavourable outcome in this mixed cohort of critically ill patients with or without SOT, whereas higher disease severity and bacteraemia negatively affected the outcome.

Surrogate infection model predicts optimal alveolar macrophage number for clearance of Aspergillus fumigatus infections

The immune system has to fight off hundreds of microbial invaders every day, such as the human-pathogenic fungus Aspergillus fumigatus. The fungal conidia can reach the lower respiratory tract, swell and form hyphae within six hours causing life-threatening invasive aspergillosis. Invading pathogens are continuously recognized and eliminated by alveolar macrophages (AM). Their number plays an essential role, but remains controversial with measurements varying by a factor greater than ten for the human lung. We here investigate the impact of the AM number on the clearance of A. fumigatus conidia in humans and mice using analytical and numerical modeling approaches. A three-dimensional to-scale hybrid agent-based model (hABM) of the human and murine alveolus allowed us to simulate millions of virtual infection scenarios, and to gain quantitative insights into the infection dynamics for varying AM numbers and infection doses. Since hABM simulations are computationally expensive, we derived and trained an analytical surrogate infection model on the large dataset of numerical simulations. This enables reducing the number of hABM simulations while still providing (i) accurate and immediate predictions on infection progression, (ii) quantitative hypotheses on the infection dynamics under healthy and immunocompromised conditions, and (iii) optimal AM numbers for combating A. fumigatus infections in humans and mice.

Prevention of acquired invasive fungal infection with decontamination regimen in mechanically ventilated ICU patients: a pre/post observational study

BACKGROUND

Invasive fungal infections acquired in the intensive care unit (AFI) are life-threating complications of critical illness. However, there is no consensus on antifungal prophylaxis in this setting. Multiple site decontamination is a well-studied prophylaxis against bacterial and fungal infections. Data on the effect of decontamination regimens on AFI are lacking. We hypothesised that multiple site decontamination could decrease the rate of AFI in mechanically ventilated patients.

METHODS

We conducted a pre/post observational study in 2 ICUs, on adult patients who required mechanical ventilation for >24 h. During the study period, multiple-site decontamination was added to standard of care. It consists of amphotericin B four times daily in the oropharynx and the gastric tube along with topical antibiotics, chlorhexidine body wash and nasal mupirocin.

RESULTS

In 870 patients, there were 27 AFI in 26 patients. Aspergillosis accounted for 20/143 of ventilator-associated pneumonia and candidemia for 7/75 of ICU-acquired bloodstream infections. There were 3/308 (1%) patients with AFI in the decontamination group and 23/562 (4%) in the standard-care group (p = 0.011). In a propensity-score matched analysis, there were 3/308 (1%) and 16/308 (5%) AFI in the decontamination group and the standard-care group respectively (p = 0.004) (3/308 vs 11/308 ventilator-associated pulmonary aspergillosis, respectively [p = 0.055] and 0/308 vs 6/308 candidemia, respectively [p = 0.037]).

CONCLUSION

Acquired fungal infection is a rare event, but accounts for a large proportion of ICU-acquired infections. Our study showed a preventive effect of decontamination against acquired fungal infection, especially candidemia.Take home messageAcquired fungal infection (AFI) incidence is close to 4% in mechanically ventilated patients without antifungal prophylaxis (3% for pulmonary aspergillosis and 1% for candidemia).Aspergillosis accounts for 14% of ventilator-associated pneumonia and candidemia for 9% of acquired bloodstream infections.Immunocompromised patients, those infected with SARS-COV 2 or influenza virus, males and patients admitted during the fall season are at higher risk of AFI.Mechanically ventilated patients receiving multiple site decontamination (MSD) have a lower risk of AFI.