Improving the rates of Aspergillus detection: an update on current diagnostic strategies

Chronic pulmonary aspergillosis in Taiwan: Disease burden, diagnosis, treatment, and outcomes

Aspergillus is a common filamentous fungus found in various natural environments, with spores frequently inhaled by humans. While healthy individuals typically resist infection, immunocompromised individuals and those with pre-existing lung diseases are at higher risk for aspergillosis. Chronic pulmonary aspergillosis (CPA) often develops in individuals with conditions like tuberculosis and chronic obstructive pulmonary disease. Recent studies in Taiwan reveal a significant incidence of CPA among elderly patients with these underlying conditions. The most common clinical manifestations include cavitation, nodules, and consolidation in the lungs. Aspergillus-specific IgG antibodies have emerged as key diagnostic markers, with varying optimal cut-off values across different regions. Studies indicate a strong correlation between high IgG levels and severe CPA, alongside associations with specific radiographic features. Additionally, elevated inflammatory markers such as IL-1β and TNF-α are linked to poor outcomes, emphasizing the need for early detection and intervention. The preferred treatment regimen consists of itraconazole, voriconazole, posaconazole, and isavuconazole, with itraconazole and voriconazole being the most extensively documented in the context of CPA. Overall, this review underscores the importance of localized diagnostic validation and comprehensive studies to improve the understanding and treatment of CPA in Taiwan.

Value Evaluation of Quantitative Aspergillus fumigatus-Specific IgG Antibody Test in the Diagnosis of Non-neutropenic Invasive Pulmonary Aspergillosis

Background

The role of Aspergillus-specific IgG antibody test in the diagnosis of non-neutropenic invasive pulmonary aspergillosis (IPA) is still uncertain, and related studies are also limited.

Purpose

This study aims to evaluate the quantitative test value of Aspergillus fumigatus-specific IgG antibody in non-neutropenic IPA, which could provide additional evidence for related clinical diagnosis.

Methods

This prospective study collected clinical data of suspected IPA patients from January, 2020 to December, 2022, and patients were divided into two groups, IPA and non-IPA. The study analyzed clinical characteristics and diagnostic value of Aspergillus-specific IgG antibody test, using the receiver operating characteristic (ROC) curve to evaluate diagnostic efficacy.

Results

The study enrolled 59 IPA cases and 68 non-IPA cases, the average admission age of IPA group was 63.2±9.6 (33-79), and the gender ratio (male:female) of IPA group was 42:17. The proportion of patients with history of smoking and COPD were higher in IPA group (59.3% vs 39.7%, P=0.027; 33.9% vs 14.7%, P =0.011, respectively). The level of Aspergillus fumigatus-specific IgG antibody in IPA group was significantly higher than non-IPA group (202.1±167.0 vs 62.6±58.0, P<0.001). The area under the ROC curve was 0.799 (95%CI: 0.718, 0.865 P<0.001), and the cut-off with best diagnostic efficacy was 91 AU/mL.

Conclusion

Immunological test plays an important role in the diagnosis of pulmonary aspergillosis, and Aspergillus-specific IgG antibody test has the good diagnostic value in non-neutropenic IPA.

Clinical Implementation of β-Tubulin Gene-Based Aspergillus Polymerase Chain Reaction for Enhanced Aspergillus Diagnosis in Patients with Hematologic Diseases: A Prospective Observational Study

The β-tubulin (benA) gene is a promising target for the identification of Aspergillus species. Assessment of the clinical implementation and performance of benA gene-based Aspergillus polymerase chain reaction (PCR) remains warranted. In this study, we assessed the analytical performance of the BenA probe PCR in comparison with the Aspergenius kit. We prospectively collected bronchoalveolar lavage (BAL) fluid via diagnostic bronchoscopy from adult patients with hematologic diseases. BenA gene-based multiplex real-time PCR and sequential melting temperature analysis were performed to detect the azole resistance of Aspergillus fumigatus. In total, 76 BAL fluids in 75 patients suspicious of invasive pulmonary aspergillosis (IPA) were collected. Before the application of PCR, the prevalence of proven and probable IPA was 32.9%. However, after implementing the benA gene-based PCR, 15.8% (12 out of 76) of potential IPA cases were reclassified as probable IPA. The analytical performance of the BenA probe PCR in BAL samples was comparable to that of the Aspergenius kit. The diagnostic performance was as follows: sensitivity, 52.0%; specificity, 64.7%; positive predictive value, 41.9%; negative predictive value, 73.3%; positive likelihood ratio, 1.473; and negative likelihood ratio, 0.741. Moreover, benA gene-based Aspergillus PCR discriminated all major sections of Aspergillus, including cryptic species such as Aspergillus tubingensis. Sequential melting temperature analysis successfully detected 2 isolates (15.4%) of A. fumigatus carrying resistant mutations. BenA gene-based Aspergillus PCR with melting temperature analysis enhances diagnostic accuracy and detects not only cryptic species but also resistant mutations of A. fumigatus. It shows promise for clinical applications in the diagnosis of IPA.

Superior Accuracy of Aspergillus Plasma Cell-Free DNA Polymerase Chain Reaction Over Serum Galactomannan for the Diagnosis of Invasive Aspergillosis

BACKGROUND

Invasive aspergillosis (IA) in immunocompromised hosts carries high morbidity and mortality. Diagnosis is often delayed because definitive diagnosis requires invasive specimen collection, while noninvasive testing with galactomannan is moderately accurate. Plasma cell-free DNA polymerase chain reaction (cfDNA PCR) represents a novel testing modality for the noninvasive diagnosis of invasive fungal disease (IFD). We directly compared the performance of Aspergillus plasma cfDNA PCR with serum galactomannan for the diagnosis of IA during routine clinical practice.

METHODS

We conducted a retrospective study of all patients with suspected IFD who had Aspergillus plasma cfDNA PCR testing at Stanford Health Care from 1 September 2020 to 30 October 2022. Patients were categorized into proven, probable, possible, and no IA based on the EORTC/MSG definitions. Primary outcomes included the clinical sensitivity and specificity for Aspergillus plasma cfDNA PCR and galactomannan.

RESULTS

Overall, 238 unique patients with Aspergillus plasma cfDNA PCR test results, including 63 positives and 175 nonconsecutive negatives, were included in this study. The majority were immunosuppressed (89.9%) with 22.3% 30-day all-cause mortality. The overall sensitivity and specificity of Aspergillus plasma cfDNA PCR were 86.0% (37 of 43; 95% confidence interval [CI], 72.7-95.7) and 93.1% (121 of 130; 95% CI, 87.4-96.3), respectively. The sensitivity and specificity of serum galactomannan in hematologic malignancies/stem cell transplants were 67.9% (19 of 28; 95% CI, 49.3-82.1) and 89.8% (53 of 59; 95% CI, 79.5-95.3), respectively. The sensitivity of cfDNA PCR was 93.0% (40 of 43; 95% CI, 80.9-98.5) in patients with a new diagnosis of IA.

CONCLUSIONS

Aspergillus plasma cfDNA PCR represents a more sensitive alternative to serum galactomannan for noninvasive diagnosis of IA.

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.

Liposomal amphotericin B—the future

Advances in medicine have led to a growing number of people with compromised or suppressed immune systems who are susceptible to invasive fungal infections. In particular, severe fungal infections are becoming increasingly common in ICUs, affecting people within and outside of traditional risk groups alike. This is exemplified by the emergence of severe viral pneumonia as a significant risk factor for invasive pulmonary aspergillosis, and the recognition of influenza-associated pulmonary aspergillosis and, more recently, COVID-19-associated pulmonary aspergillosis.

The treatment landscape for haematological malignancies has changed considerably in recent years, and some recently introduced targeted agents, such as ibrutinib, are increasing the risk of invasive fungal infections. Consideration must also be given to the risk of drug–drug interactions between mould-active azoles and small-molecule kinase inhibitors.

At the same time, infections caused by rare moulds and yeasts are increasing, and diagnosis continues to be challenging. There is growing concern about azole resistance among both moulds and yeasts, mandating continuous surveillance and personalized treatment strategies.

It is anticipated that the epidemiology of fungal infections will continue to change and that new populations will be at risk. Early diagnosis and appropriate treatment remain the most important predictors of survival, and broad-spectrum antifungal agents will become increasingly important. Liposomal amphotericin B will remain an essential therapeutic agent in the armamentarium needed to manage future challenges, given its broad antifungal spectrum, low level of acquired resistance and limited potential for drug–drug interactions.

EQUAL CPA Score 2022: a tool to measure guideline adherence for chronic pulmonary aspergillosis

BACKGROUND

Chronic pulmonary aspergillosis (CPA) can complicate underlying pulmonary diseases, and clinical management of CPA is challenging. Guidelines support clinicians but due to the complexity of the disease they can be difficult to adhere to.

OBJECTIVES

To map current guideline recommendations for the clinical management of CPA into a scoring tool to facilitate and quantify guideline adherence in clinical practice.

METHODS

Recommendations for diagnosis, treatment and follow-up of CPA presented in the current ESCMID/ERS/ECMM and CPAnet guidance documents were assembled and weighed on the basis of their strength of recommendation and level of evidence.

RESULTS

Twenty-seven recommendations were identified, resulting in a total maximum EQUAL CPA Score of 51. For diagnostics (ScoreMax = 27), a strong emphasis on expert consultation, culture, direct microscopy, histopathology, serology and imaging was reflected in respective points, whereas molecular techniques and susceptibility testing count into the diagnostics score to a lesser extent.Ten treatment recommendations (ScoreMax = 14), including antifungal therapy, therapeutic drug monitoring and treatment duration, were identified. Surgery, where indicated, adds three points. For refractory disease or intolerance of first-line antifungal treatment, optimal second-line treatment added another two points.During follow-up (ScoreMax = 10), response assessment via imaging gave three points, while culture and serology added two points each to the ScoreMax.

CONCLUSION

The EQUAL CPA Score intents to be used as a comprehensive tool for measuring guideline adherence. If adherence to current guidelines is associated with clinical outcome, this will be assessed in future studies.

Growth Performance and Recovery of Nosocomial Aspergillus spp. in Blood Culture Bottles

Theoretically, Aspergillus spp. grow in culture media, but frequently, blood cultures of patients with invasive Aspergillosis are negative, even if until now, the reasons are not clear. This aspect underlines the lack of a good strategy for the cultivation and isolation of Aspergillus spp. In order to develop a complete analytical method to detect Aspergillus in clinical and pharmaceutical samples, we investigated the growth performance of two blood culture systems versus the pharmacopeia standard method. At <72 h, all test systems showed comparable sensitivity, about 1−2 conidia. However, the subculture analysis showed a suboptimal recovery for the methods, despite the positive growth and the visualization of the “Aspergillus balls” in the culture media. To investigate this issue, we studied three different subculture approaches: (i) the use of a sterile subculture unit, (ii) the use of a sterile subculture unit and the collection of a larger aliquot (100 µL), following vigorous agitation of the vials, and (iii) to decapsulate the bottle, withdrawing and centrifuging the sample, and aliquot the pellet onto SDA plates. Our results showed that only the third procedure recovered Aspergillus from all positive culture bottles. This work confirmed that our strategy is a valid and faster method to culture and isolate Aspergillus spp. from blood culture bottles.

Epidemiology of Aspergillosis in Cancer Patients in Taiwan

Purpose

The incidence of aspergillosis is increasing, and the risk factors for infection include cancer, admission to the intensive care unit, chronic pulmonary diseases, immunocompromised status, and taking immunomodulatory drugs. There are limited data about the incidence of aspergillosis in patients with different types of cancer. The aim of our study was to survey the incidence of aspergillosis in different cancer types from 2006 to 2017.

Patients and Methods

Data were collected from the Taiwan Cancer Registry database and International Classification of Diseases, 9th, 10th Revision, and Clinical Modification codes for diagnosing aspergillosis. Patients with a history of aspergillosis before cancer were excluded, and the secondary outcome was the risk of mortality in cancer patients with and without aspergillosis after 1 year.

Results

Among 951 cancer patients with a diagnosis of aspergillosis, there were 614 hematopoietic and reticuloendothelial system patients, 100 lung cancer patients, and 73 lymphoma cancer patients. The overall incidence rates of aspergillosis tended to increase significantly from 2006 to 2017 (from 3.50 to 13.37 per 10,000 person-years, p value: <0.0001). Regarding sex, the incidence rates of aspergillosis in males and females were 12.52 and 7.53 per 10,000 person-years, respectively. Patients with a diagnosis of aspergillosis had a 2.30-fold (95% CI: 2.14–2.48, p value: <0.0001) higher risk of mortality than those without aspergillosis.

Conclusion

The incidence of aspergillosis was increased in cancer patients, and cancer patients with aspergillosis had a significantly higher risk of mortality than those without aspergillosis.

Heterogeneous imaging features of Aspergillosis at 18F-FDG PET/CT

Aspergillosis is one of the most frequent fungal infections, whose morbidity can be life-threatening, especially in some categories of patients such as immunocompromised ones. It can have various clinical presentation scenarios and should be considered when making differential diagnosis in patients with pulmonary and extrapulmonary involvement. 18F-FDG PET/CT is a whole-body diagnostic technique that can help in the study of the disease, guiding the patient management thanks to the possibility to recognize infection sites and extension. The aim of this manuscript is to provide an overview of the wide spectrum of disease presentation. Literature regarding 18F-FDG PET/CT in histologically confirmed aspergillosis cases has been revised to describe all its possible features, both usual and unusual to guide imaging interpretation. 18F-FDG PET/CT is a diagnostic tool that can help in the recognition of the heterogenous infection’s presentation, allowing the clinicians to make a prompt diagnosis and to have the most accurate management of the disease. Furthermore, other PET/CT radiopharmaceutical role in Aspergillosis imaging study have been presented.

Performance of the Euroimmun Aspergillus Antigen ELISA for the Diagnosis of Invasive Pulmonary Aspergillosis in Bronchoalveolar Lavage Fluid

Invasive pulmonary aspergillosis (IPA) is a life-threatening disease that affects mainly immunocompromised hosts. Galactomannan testing from serum and bronchoalveolar lavage fluid (BALF) represents a cornerstone in diagnosing the disease. Here, we evaluated the diagnostic performance of the novel Aspergillus-specific galactomannoprotein (GP) enzyme-linked immunosorbent assay (ELISA; Euroimmun Medizinische Labordiagnostika) compared with the established Platelia Aspergillus GM ELISA (GM; Bio-Rad Laboratories) for the detection of Aspergillus antigen in BALF. Using the GP ELISA, we retrospectively tested 115 BALF samples from 115 patients with clinical suspicion of IPA and GM analysis ordered in clinical routine. Spearman's correlation statistics and receiver operating characteristics (ROC) curve analysis were performed. Optimal cutoff values were determined using Youden's index. Of 115 patients, 1 patient fulfilled criteria for proven IPA, 42 for probable IPA, 15 for putative IPA, 10 for possible IPA, and 47 did not meet criteria for IPA. Sensitivities and specificities for differentiating proven/probable/putative versus no IPA (possible excluded) were 74% and 96% for BALF GP and 90% and 96% for BALF GM at the manufacturer-recommended cutoffs. Using the calculated optimal cutoff value of 12 pg/mL, sensitivity and specificity of the BALF GP were 90% and 96%, respectively. ROC curve analysis showed an area under the curve (AUC) of 0.959 (95% confidence interval [CI] of 0.923 to 0.995) for the GP ELISA and an AUC of 0.960 (95% CI of 0.921 to 0.999) for the GM ELISA for differentiating proven/probable/putative IPA versus no IPA. Spearman's correlation analysis showed a strong correlation between the ELISAs (rho = 0.809, P < 0.0001). The GP ELISA demonstrated strong correlation and test performance similar to that of the GM ELISA and could serve as an alternative test for BALF from patients at risk for IPA.

Aspergillus fumigatus and aspergillosis: From basics to clinics

The airborne fungus Aspergillus fumigatus poses a serious health threat to humans by causing numerous invasive infections and a notable mortality in humans, especially in immunocompromised patients. Mould-active azoles are the frontline therapeutics employed to treat aspergillosis. The global emergence of azole-resistant A. fumigatus isolates in clinic and environment, however, notoriously limits the therapeutic options of mould-active antifungals and potentially can be attributed to a mortality rate reaching up to 100 %. Although specific mutations in CYP 51A are the main cause of azole resistance, there is a new wave of azole-resistant isolates with wild-type CYP 51A genotype challenging the efficacy of the current diagnostic tools. Therefore, applications of whole-genome sequencing are increasingly gaining popularity to overcome such challenges. Prominent echinocandin tolerance, as well as liver and kidney toxicity posed by amphotericin B, necessitate a continuous quest for novel antifungal drugs to combat emerging azole-resistant A. fumigatus isolates. Animal models and the tools used for genetic engineering require further refinement to facilitate a better understanding about the resistance mechanisms, virulence, and immune reactions orchestrated against A. fumigatus. This review paper comprehensively discusses the current clinical challenges caused by A. fumigatus and provides insights on how to address them.

Performance characteristics of Fungitell STAT™, a rapid (1→3)-β-D-glucan single patient sample in vitro diagnostic assay

Serum (1→3)-β-D-glucan (BDG), is an adjunct test in the diagnosis of invasive fungal disease (IFD). Fungitell STAT™, a facile, rapid, single patient option, executable for one or more patient specimens in approximately an hour, has been developed to address a need for rapid in-house testing. This method presents qualitative information concerning serum BDG levels, using an index value that allows the rapid categorization of patients as positive, negative, or indeterminate relative to serum BDG titer. The categorical and analytical performance of Fungitell STAT was evaluated. The categorical agreement between methods was established by testing patient samples which had been previously categorized with Fungitell. Receiver Operating Characteristic curves were used to identify cut-offs using 93 de-identified patient specimens. Subsequently, using these cutoffs, an independent group of 488 patient specimens was analyzed. Positive percent agreement (PPA) with, and without, indeterminate results was 74% and 99%, respectively. Negative percent agreement (NPA) was 91% and 98% with, and without, indeterminate results, respectively. Additionally, commercially available normal off-the-clot sera were spiked with Saccharomyces cerevisiae-derived (1→3)-β-D-glucan to produce analytical samples. Analytical reproducibility using spiked samples was excellent with 94% of the CV (coefficient of variation) values ≤10% among three independent laboratories. Good correlation with the predicate method was demonstrated with correlation coefficients of 0.90 or better with patient samples and 0.99 with spiked samples. The Fungitell STAT index assay provides a rapid and suitable method for serum BDG testing.

Evaluation of a Prototype of a Novel Galactomannan Sandwich Assay Using the VIDAS® Technology for the Diagnosis of Invasive Aspergillosis

Objectives

To evaluate the analytical and clinical performance of a prototype of a VIDAS^® Galactomannan (GM) unitary test (bioMérieux, Marcy l’Etoile, France) and compare to that of the Platelia™ Aspergillus Ag assay (Bio-Rad, CA, USA).

Methods

Repeatability, reproducibility, and freeze-thaw stability of VIDAS^®GM were evaluated. Sera from patients at risk of IA were concurrently tested with both the VIDAS^®GM and Platelia™ Aspergillus Ag assays. Correlations between the two assays were assessed by Passing Bablok (PB) regression and performance by ROC analysis.

Results

The correlations between the VIDAS^®GM indexes after one and two cycles of freezing/thawing were r=1.00 and r=0.989, respectively. The coefficients of variation for negative, low-positive, and positive sera were 13%, 6%, and 5% for repeatability and 14.4%, 7.2%, and 5.5% for reproducibility. Overall, 126 sera were tested with both assays (44 fresh and 82 frozen). The correlation between VIDAS^®GM and Platelia™ Aspergillus Ag was r=0.798. The areas under the curve of the ROC analyses were 0.892 and 0.894, for VIDAS^®GM and Platelia™ Aspergillus Ag, respectively.

Conclusions

This new VIDAS^®GM prototype assay showed adequate analytical and clinical performance and a good correlation with that of Platelia™ Aspergillus Ag with 126 sera, although these results need to be confirmed in a larger prospective and multicentric study. As for the other VIDAS^® assays, VIDAS^®GM is a single-sample automated test using a solid reagent strip and receptacle. It is easy to use and suitable for rapid on-demand test results.

Identification of Aspergillus species in human blood plasma by infrared spectroscopy and machine learning

Invasive Aspergillosis is a challenging infection that requires convenient, efficient, and cost-effective diagnostics. This study addresses the potential of infrared spectroscopy to satisfy this clinical need with the aid of machine learning. Two models, based on Partial Least Squares-Discriminant Analysis (PLS-DA), have been trained by a set of infrared spectral data of 9 Aspergillus-spiked and 7 Aspergillus-free plasma samples, and a set of 200 spectral data simulated by oversampling these 16 samples. Two further models have also been trained by the same sets but with auto-scaling performed prior to PLS-DA. These models were assessed using 45 mock samples, simulating the challenging samples of patients at risk of Invasive Aspergillosis, including the presence of drugs (9 tested) and other common pathogens (5 tested) as potential confounders. The simple model shows good prediction performance, yielding a total accuracy of 84.4%, while oversampling and autoscaling improved this accuracy to 93.3%. The results of this study have shown that infrared spectroscopy can identify Aspergillus species in blood plasma even in presence of potential confounders commonly present in blood of patients at risk of Invasive Aspergillosis.

The Aspergillus Lateral Flow Assay for the Diagnosis of Invasive Aspergillosis: an Update

Purpose of Review

To review the data on the Aspergillus lateral flow assay for the diagnosis of invasive Aspergillosis.

Recent Findings

Aspergillus spp. cause a wide spectrum of disease with invasive aspergillosis (IA) as its most severe manifestation. Early and reliable diagnosis of disease is crucial to decrease associated morbidity and mortality, and enable prompt initiation of treatment for IA. Most recently, non-culture-based tests, such as Aspergillus galactomannan (GM), have been useful in early identification and treatment of patients with IA. However, cost, turnaround time, and variable performance indifferent populations at risk for IA remain significant drawbacks to the use of this test. Several diagnostic tests for IA have been developed, including the sōna Aspergillus GM Lateral flow assay (GM-LFA) rapid test.

Summary

The GM-LFA has shown excellent performance for the diagnosis of IA in patients with hematologic malignancy and may be a viable option for settings where ELISA GM testing is not feasible. Further evaluation of the GM-LFA in the non-hematology setting is ongoing, including in solid organ transplant recipients and patients in the intensive care unit.

Diagnosis of Breakthrough Fungal Infections in the Clinical Mycology Laboratory: An ECMM Consensus Statement

Breakthrough invasive fungal infections (bIFI) cause significant morbidity and mortality. Their diagnosis can be challenging due to reduced sensitivity to conventional culture techniques, serologic tests, and PCR-based assays in patients undergoing antifungal therapy, and their diagnosis can be delayed contributing to poor patient outcomes. In this review, we provide consensus recommendations on behalf of the European Confederation for Medical Mycology (ECMM) for the diagnosis of bIFI caused by invasive yeasts, molds, and endemic mycoses, to guide diagnostic efforts in patients receiving antifungals and support the design of future clinical trials in the field of clinical mycology. The cornerstone of lab-based diagnosis of breakthrough infections for yeast and endemic mycoses remain conventional culture, to accurately identify the causative pathogen and allow for antifungal susceptibility testing. The impact of non-culture-based methods are not well-studied for the definite diagnosis of breakthrough invasive yeast infections. Non-culture-based methods have an important role for the diagnosis of breakthrough invasive mold infections, in particular invasive aspergillosis, and a combination of testing involving conventional culture, antigen-based assays, and PCR-based assays should be considered. Multiple diagnostic modalities, including histopathology, culture, antibody, and/or antigen tests and occasionally PCR-based assays may be required to diagnose breakthrough endemic mycoses. A need exists for diagnostic tests that are effective, simple, cheap, and rapid to enable the diagnosis of bIFI in patients taking antifungals.

Point-of-care diagnostics for invasive aspergillosis: nearing the finish line

INTRODUCTION

The spectrum of disease caused by Aspergillus spp. is dependent on the immune system of the host, with invasive aspergillosis (IA) its most severe manifestation. Early and reliable diagnosis of Aspergillus disease is important to decrease associated morbidity and mortality from IA.

AREAS COVERED

The following review searched Pub Med for literature published since 2007 and will give an update on the current point-of-care diagnostic strategies for the diagnosis of IA, discuss needed areas of improvement for these tests, and future directions.

EXPERT OPINION

Several new diagnostic tests for IA - including point-of-care tests - are now available to complement conventional galactomannan (GM) testing. In particular, the Aspergillus-specific Lateral Flow Device (LFD) test and the sōna Aspergillus GM Lateral Flow Assay (LFA) are promising for the diagnosis of IA in patients with hematologic malignancy, although further evaluation in the non-hematology setting is needed. In addition, a true point-of-care test, particularly for easily obtained specimens like serum or urine that can be done at the bedside or in the Clinic in a matter of minutes is needed, such as the lateral flow dipstick test, which is under current evaluation. Lastly, improved diagnostic algorithms to diagnose IA in non-neutropenic patients is needed.

Perlin D, Lass-Flörl C, Hoenigl M. COVID-19 Associated Pulmonary Aspergillosis (CAPA)-From Immunology to Treatment

Like severe influenza, coronavirus disease-19 (COVID-19) resulting in acute respiratory distress syndrome (ARDS) has emerged as an important disease that predisposes patients to secondary pulmonary aspergillosis, with 35 cases of COVID-19 associated pulmonary aspergillosis (CAPA) published until June 2020. The release of danger-associated molecular patterns during severe COVID-19 results in both pulmonary epithelial damage and inflammatory disease, which are predisposing risk factors for pulmonary aspergillosis. Moreover, collateral effects of host recognition pathways required for the activation of antiviral immunity may, paradoxically, contribute to a highly permissive inflammatory environment that favors fungal pathogenesis. Diagnosis of CAPA remains challenging, mainly because bronchoalveolar lavage fluid galactomannan testing and culture, which represent the most sensitive diagnostic tests for aspergillosis in the ICU, are hindered by the fact that bronchoscopies are rarely performed in COVID-19 patients due to the risk of disease transmission. Similarly, autopsies are rarely performed, which may result in an underestimation of the prevalence of CAPA. Finally, the treatment of CAPA is complicated by drug-drug interactions associated with broad spectrum azoles, renal tropism and damage caused by SARS-CoV-2, which may challenge the use of liposomal amphotericin B, as well as the emergence of azole-resistance. This clinical reality creates an urgency for new antifungal drugs currently in advanced clinical development with more promising pharmacokinetic and pharmacodynamic profiles.

An overview of the available treatments for chronic cavitary pulmonary aspergillosis

INTRODUCTION

Chronic pulmonary aspergillosis (CPA) is a chronic lung infection caused by Aspergillus fumigatus, that complicates structural lung diseases. Of the different types of CPA, chronic cavitary pulmonary aspergillosis (CCPA) is the most common form. The mainstay of treatment of CCPA is oral triazoles. However, many gaps exist in clinical decision-making about the agent of choice, the duration, and the assessment of treatment response.

AREAS COVERED

We discuss the approach to diagnosis and treatment of CCPA. We have searched the PubMed and EmBase databases (from inception till 31 October 2019) to identify studies describing the use of anti-fungal agents in CCPA.

EXPERT OPINION

Treatment for CCPA should be initiated with oral itraconazole for at least six months. In case of poor response or intolerance to itraconazole, voriconazole should be considered. Intravenous agents, including amphotericin B and echinocandins, may be used in those with either treatment failure or those who are intolerant to oral antifungal agents. Posaconazole and isavuconazole may be used as salvage therapy due to a better pharmacokinetic/pharmacodynamic profile of the former and reduced drug-drug interactions with the latter.

Blood Aspergillus PCR: The Good, the Bad, and the Ugly

Invasive Aspergillosis (IA) is one of the most common invasive fungal diseases and is accompanied by high morbidity and mortality. In order to maximize patient outcomes and survival, early and rapid diagnosis has been shown to be pivotal. Hence, diagnostic tools aiding and improving the diagnostic process are ambitiously searched for. In this context, polymerase chain reaction (PCR) may represent a potential candidate. Its additional value and benefits in diagnosis have been demonstrated and are scientifically established. Nevertheless, standardized and widespread usage is sparse because several factors influence diagnostic quality and need to be considered in order to optimize diagnostic performance and outcome. In the following review, the current role of PCR in the diagnosis of IA is explored, with special focus on the strengths and limitations of PCR in different settings.

Seroprevalence of Aspergillus IgG and disease prevalence of chronic pulmonary aspergillosis in a country with intermediate burden of tuberculosis: a prospective observational study

OBJECTIVES

Chronic pulmonary aspergillosis (CPA) is an emerging global disease with tuberculosis (TB) being the most important risk factor. Epidemiologic data on the seroprevalence of Aspergillus IgG and prevalence of CPA in different areas, especially in country with intermediate burden of TB, are lacking.

METHODS

We prospectively recruited healthy volunteers, TB close contacts, active TB patients and participants with old pulmonary TB in Taiwan during 2012-2019. We measured serum Aspergillus fumigatus and niger-specific IgG levels and assessed if the participants were having CPA.

RESULTS

A total of 1242 participants (including 200 healthy volunteers, 326 TB close contacts, 524 active TB patients and 192 old TB cases) were recruited. Using 27 mgA/L (milligrams of antigen-specific antibodies per liter) as cut-off level, the seropositive rate of A. fumigatus-specific IgG was 33.0% (66/200), 37.7% (123/326), 26.5% (139/524) and 43.2% (83/192) among the four groups, respectively. In multivariate logistic regression, pulmonary cavitation (OR 1.73; 95% CI 1.07-2.80), female sex (OR 1.49; 95% CI 1.14-1.95), old TB (OR 1.59; 1.05-2.42) were independent risk factors for Aspergillus IgG positivity. One (0.2%) active TB patient and four (2.1%) old TB patients developed CPA. Correlation between A. fumigatus and A. niger-specific IgG was high (Spearman correlation coefficient: 0.942).

DISCUSSION

Geographic variation in Aspergillus IgG seroprevalence and CPA prevalence exists. A universal cut-off value for Aspergillus IgG may not exist. In areas and populations in which background Aspergillus IgG level is unknown, Aspergillus IgG may be better used as a test of exclusion for CPA using prespecified cut-off level.

(New) Methods for Detection of Aspergillus fumigatus Resistance in Clinical Samples

PURPOSE OF REVIEW

The incidence of invasive aspergillosis has increased substantially over the past few decades, accompanied by a change in susceptibility patterns of Aspergillus fumigatus with increasing resistance observed against triazole antifungals, including voriconazole and isavuconazole, the most commonly used antifungal agents for the disease. Culture-based methods for determining triazole resistance are still the gold standard but are time consuming and lack sensitivity. We sought to provide an update on non-culture-based methods for detecting resistance patterns to Aspergillus.

RECENT FINDINGS

New molecular-based approaches for detecting triazole resistance to Aspergillus, real-time polymerase chain reaction (PCR) to detect mutations to the Cyp51A protein, have been developed which are able to detect most triazole-resistant A. fumigatus strains in patients with invasive aspergillosis.

SUMMARY

Over the last few years, a number of non-culture-based methods for molecular detection of Aspergillus triazole resistance have been developed that may overcome some of the limitations of culture. These molecular methods are therefore of high epidemiological and clinical relevance, mainly in immunocompromised patients with hematological malignancies, where culture has particularly limited sensitivity. These assays are now able to detect most triazole-resistant Aspergillus fumigatus strains. Given that resistance rates vary, clinical utility for these assays still depends on regional resistance patterns.