Comparison of 1,3-β-d-glucan with galactomannan in serum and bronchoalveolar fluid for the detection of Aspergillus species in immunosuppressed mechanical ventilated critically ill patients

The epidemiological characteristics of invasive pulmonary aspergillosis and risk factors for treatment failure: a retrospective study

OBJECTIVE

The incidence of invasive pulmonary aspergillosis (IPA) is increasing gradually. This study analysed the epidemiological characteristics and prognostic factors of patients with IPA and explored the risk factors affecting prognosis.

MATERIALS AND METHODS

The clinical data and treatment of 92 patients with IPA were retrospectively analysed, and the patients were followed for 12 weeks. Patients were divided into an effective treatment group and an ineffective treatment group, and the risk factors affecting prognosis were discussed.

RESULTS

A total of 92 patients met the IPA inclusion criteria, and the most common genus of Aspergillus was Aspergillus fumigatus. The incidence of IPA was highest in patients with malignant tumours. IPA often coexisted with infections caused by other pathogens. We divided the patients into an effective treatment group and an ineffective treatment group according to prognosis. Compared with those in the effective treatment group, the procalcitonin (PCT) level, lactate dehydrogenase-to-albumin ratio (LDH/ALB) and neutrophil-to-lymphocyte ratio (NLR) in the ineffective treatment group were greater, the serum albumin level was lower, and the imaging findings revealed less nodules and bronchial wall thickening (P < 0.05). Among these factors, a decrease in the serum albumin concentration, an increase in the PCT level, coinfection and less bronchial wall thickening on imaging were independent risk factors for aspergillosis treatment failure.

CONCLUSION

A decreased albumin level, an elevated PCT level, coinfection, and less bronchial wall thickening were independent risk factors for treatment failure in patients with IPA. Attention should be given to the albumin level, coinfection status and imaging findings of patients.

Metagenomic next-generation sequencing for the diagnosis of invasive pulmonary aspergillosis in type 2 diabetes mellitus patients

Invasive pulmonary aspergillosis (IPA) in patients with diabetes mellitus has high incidence, especially in Type 2 diabetes mellitus (T2DM). The aim of this study was to evaluate the diagnostic efficacy of metagenomic next-generation sequencing (mNGS) for IPA in patients with T2DM. A total of 66 patients with T2DM were included, including 21 IPA and 45 non-IPA patients, from January 2022 to December 2022. The demographic characteristics, comorbidities, laboratory test results, antibiotic treatment response, and 30-day mortality rate of patients were analyzed. The diagnostic accuracy of mNGS and conventional methods was compared, including sensitivity, specificity, positive predictive value and negative predictive value. The sensitivity and specificity of mNGS were 66.7% and 100.0%, respectively, which were significantly higher than those of fluorescence staining (42.1% and 100%), serum 1,3-β-D-glucan detection (38.1% and 90.9%), serum galactomannan detection (14.3% and 94.9%) and BALF galactomannan detection (47.3% and 70.7%). Although the sensitivity of BALF culture (75.0%) was higher than that of mNGS (66.7%), the turnover time of mNGS was significantly shorter than that of traditional culture (1.6 days vs. 5.0 days). The sensitivity of mNGS combined with BALF culture reached 100.0%. In addition, mNGS has a stronger ability to detect co-pathogens with IPA. 47.6% of T2DM patients with IPA were adjusted the initial antimicrobial therapy according to the mNGS results. This is the first study to focus on the diagnostic performance of mNGS in IPA infection in T2DM patients. MNGS can be used as a supplement to conventional methods for the diagnosis of IPA in patients with T2DM.

Diagnostic performance of serum galactomannan and β-D-glucan for invasive aspergillosis in suspected patients: A meta-analysis

BACKGROUND

Serum galactomannan (GM) and β-D-glucan (BG) are known markers of invasive aspergillosis (IA). The aim of this meta-analysis was to evaluate the efficiency of serum GM and BG as diagnostic markers of symptomatic IA infection and compare the performance of the combined tests with that of either test individually.

METHODS

A literature search was carried out using PubMed, Web of Science, and EMBASE databases to include relevant studies published in English up to May 2023. The quality assessment was performed using Review Manager 5.3 software. A bivariate model was applied to pool diagnostic parameters using Stata 14.0 software. We used Cochrane I2 index to assess heterogeneity and identify the potential source of heterogeneity by meta-regression. Paired t tests were used to compare the value of GM and BG for IA diagnosis when used in combination or alone.

RESULTS

Sixteen studies were eligible for inclusion in the meta-analysis. For proven or probable IA, serum GM and BG yielded a pooled sensitivity of 0.53 (95% CI 0.40-0.66) vs 0.72 (95% CI 0.61-0.81) and a pooled specificity of 0.94 (95% CI 0.91-0.97) vs 0.82 (95% CI 0.73-0.88). The area under the curve (AUC) of ROC was 0.90 (95% CI 0.87-0.92) vs 0.83 (95% CI 0.80-0.86) for all studies. The pooled sensitivity and specificity for IA diagnosis by combined GM and BG assays (GM/BG) were 0.84 (95% CI 0.69-0.86) and 0.76 (95% CI 0.69-0.81), respectively. The sensitivity of the combined GM/BG test to diagnose IA was higher than of the GM or BG test alone.

CONCLUSION

Serum GM and BG tests had a relatively high accuracy for IA diagnosis in suspected patients. The diagnostic accuracy of both assays is comparable, and the diagnostic sensitivity is further improved by the combined detection of the 2 markers.

Diagnosis by metagenomic next-generation sequencing of invasive pulmonary aspergillosis in an infant with chronic granulomatous disease

Invasive pulmonary aspergillosis (IPA) is a serious fungal infection, with a high degree of mortality in immunocompromised individuals. Diagnosis of IPA is challenging in that clinical manifestations are not specific, with sensitivity of traditional detection procedures low. We report a case of IPA in a chronic granulomatous disease (CGD) infant who was initially suspected to have a lung tumor. Aspergillus fumigatus was identified as the pathogen in bronchoalveolar lavage fluid (BALF) by next-generation sequencing (mNGS). The patient recovered rapidly following a change of appropriate antifungal treatment and was discharged. This case highlights the additional value of BALF-mNGS for the diagnosis of pediatric invasive pulmonary fungal infection in immune-deficient children.

Diagnostic value of bronchoalveolar lavage fluid galactomannan assay for invasive pulmonary aspergillosis in adults: A meta-analysis

WHAT IS KNOWN AND OBJECTIVE

To analyse the diagnostic accuracy of bronchoalveolar lavage fluid galactomannan (BALF-GM) assay for invasive pulmonary aspergillosis (IPA) in adults to determine the optimal diagnostic cut-off by meta-analysis.

METHODS

PubMed, Embase, Web of Science, Cochrane Library, China national knowledge infrastructure (CNKI), and China Wanfang databases were searched to collect relevant studies on the diagnostic value of BALF-GM for IPA from inception to March 2022. The summary receiver operating characteristic (SROC) curve was drawn to determine the optimal diagnostic cut-off.

RESULTS AND DISCUSSION

Nineteen articles (56 data sets) were included. The pooled sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR) were 0.79 (95% CI: 0.72-0.84), 0.92 (95% CI: 0.88-0.94), 9.25 (95% CI: 6.84-12.52), 0.23 (95% CI: 0.18-0.30), 39.44 (95% CI: 29.55-52.65), and 0.92 (95% CI: 0.90-0.94), respectively. The area under the curves (AUCs) were 0.92, 0.86, 0.93, 0.89, 0.88, and 0.94 when the cut-off values were 0.5, 0.8, 1.0, 1.5, 2.0, and 3.0, respectively. Sixteen studies were included in the combined analysis when the cut-off value was 0.5. The results showed that the pooled sensitivity, specificity, PLR, NLR and DOR of BALF-GM (cut-off 0.5) for the diagnosis of IPA were 0.89 (95% CI: 0.83-0.93), 0.79 (95% CI: 0.71-0.86), 4.33 (95% CI: 3.04-6.16), 0.14 (95% CI: 0.09-0.22), and 31.51 (95% CI: 17.43-56.98). The AUC was 0.92 (95% CI: 0.89-0.94).

WHAT IS NEW AND CONCLUSIONS

BALF-GM has excellent diagnostic accuracy for adult IPA, which can be diagnosed early and treated early to reduce the mortality rate. Considering the sensitivity, specificity, PLR and NLR, the recommended diagnostic cut-off of BALF-GM for adult IPA is 0.5.

The lung in inborn errors of immunity: From clinical disease patterns to molecular pathogenesis

In addition to being a vital organ for gas exchange, the lung is a crucial immune organ continuously exposed to the external environment. Genetic defects that impair immune function, called inborn errors of immunity (IEI), often have lung disease as the initial and/or primary manifestation. Common types of lung disease seen in IEI include infectious complications and a diverse group of diffuse interstitial lung diseases. Although lung damage in IEI has been historically ascribed to recurrent infections, contributions from potentially targetable autoimmune and inflammatory pathways are now increasingly recognized. This article provides a practical guide to identifying the diverse pulmonary disease patterns in IEI based on lung imaging and respiratory manifestations, and integrates this clinical information with molecular mechanisms of disease and diagnostic assessments in IEI. We cover the entire IEI spectrum, including immunodeficiencies and immune dysregulation with monogenic autoimmunity and autoinflammation, as well as recently described IEI with pulmonary manifestations. Although the pulmonary manifestations of IEI are highly relevant for all age groups, special emphasis is placed on the pediatric population, because initial presentations often occur during childhood. We also highlight the pivotal role of genetic testing in the diagnosis of IEI involving the lungs and the critical need to develop multidisciplinary teams for the challenging evaluation of these rare but potentially life-threatening disorders.

Risk factors and clinical impact of COVID-19-associated pulmonary aspergillosis: Multicenter retrospective cohort study

BACKGROUND/AIMS

The risk factors and clinical impacts of coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) remain controversial, and no data have been reported in Korea. This study aimed to investigate the epidemiology and importance of CAPA diagnostic efforts and to identify the predictors of CAPA and the impacts on clinical outcomes.

METHODS

Between January 2020 and May 2021, data of severely to critically ill COVID-19 patients were extracted from seven hospitals of the Catholic Medical Center through a clinical data warehouse. Corticosteroid use was subcategorized into total cumulative dose, early 7-day dose, mean daily dose, and duration of use.

RESULTS

A total of 2,427 patients were screened, and 218 patients were included. CAPA was diagnosed in 4.6% (10/218) of all hospitalized and 11.2% (10/89) of intensive care unit patients. Total cumulative dose (over 1,000 mg as methylprednisolone) and daily high-dose corticosteroid use (over 60 mg/day) were independent predictors but not early 7-day high-dose corticosteroid use (over 420 mg/week) (odds ratio [OR], 1.731; 95% confidence interval [CI], 0.350 to 8.571) nor prolonged use (OR, 2.794; 95% CI, 0.635 to 13.928). In-hospital overall mortality was 11.9% (26 of 218). CAPA itself did not affect the outcome; rather, daily high-dose steroid use significantly increased the 30-day mortality (hazard ratio, 5.645; 95% CI, 1.225 to 26.091).

CONCLUSION

CAPA was not uncommon, especially in critically ill patients. Daily high-dose corticosteroid use was the predictor of CAPA and associated with high mortality rates. High-dose corticosteroids use after early inflammatory phase should be avoided, and active surveillance methods for CAPA are essential for those high-risk patients.

Evaluation of (1,3)--d-glucan assay in diagnosis of invasive fungal infections with Aspergillus

Invasive fungal infections caused by Aspergillus are a significant problem in immunocompromised and critically ill patients and associated with increased morbidity and mortality. Early diagnosis of invasive aspergillosis is still a big clinical and diagnostic challenge. Conventional methods are not sensitive enough, and therefore, there is a need for rapid, more sensitive methods for early diagnosis of invasive fungal infections with Aspergillus. The aim of this study was to evaluate the diagnostic performance, sensitivity and specificity of serological panfungal (1,3)-b-D-glucan marker compared to conventional method for diagnosis of invasive fungal infections with Aspergillus. Material and methods: Specimens of 125 patients divided into 4 groups (group I - immune deficiency, group II - prolonged ICU stay, group III - chronic aspergillosis, group IV - cystic fibrosis), classified according to clinical diagnosis and EORTC/MSG criteria, were analyzed at the Institute of Microbiology and Parasitology, with conventional and serological methods, during a period of two years. Results: A total of 71 isolates of Aspergillus were confirmed in this study. Four isolates were recovered from bloodculture of patients with primary immune deficiency. With BAL culture, Aspergillus was detected in the group of chronic aspergillosis (63.33%), followed by the groups of cystic fibrosis (56.67%), primary immune deficiency (51.43%), and the group with prolonged ICU stay (43.33%). Sensitivity and specificity of BAL culture were: 64.29% and 100%, 59.09% and 100%, 54.55% and 12.5%, 100% and 54.17%, in I, II, III and IV group, respectively. In 79.1% (53/67) from positive BAL cultures in all groups, A. fumigatus was confirmed, of which, 32.1% (17/53) in group III, followed by group I – 26.42% (14/53) and group IV – 26.42% (14/53), and 15.1% (8/53) in group II. Other species confirmed in BAL were A. flavus 16.42% (11/67) and A.terreus 4.48% (3/67). Sensitivity and specificity of the serological panfungal (1,3)-b-D-glucan (BDG) marker were: 64.71% and 85.71%, 50% and 87.5%, 36.36% and 50%, in groups I, II and III, respectively. No positive findings of the panfungal (1,3)-b-D-glucan (BDG) marker were found in the group with cystic fibrosis. Conclusion: The results obtained in this study have demonstrated that a positive (1,3)-b-D-glucan assay highlights the value of this test as a diagnostic adjunct in the serodiagnosis of invasive fungal infections with Aspergillus, and along with the results from conventional mycological investigation, helped in reaching a timely antifungal treatment with a favorable clinical outcome.  

Routine Surveillance of Healthcare-Associated Infections Misses a Significant Proportion of Invasive Aspergillosis in Patients with Severe COVID-19

Rates of invasive aspergillosis (IA) among COVID-19 ICU patients seem to reach over 30% in certain settings. At Vienna General Hospital (VGH), all rooms in COVID-19 ICUs were put under negative pressure as a protective measure, thus increasing the risk of exposure to environmental pathogens for patients. Even though all ICU patients are surveilled for healthcare-associated infections (HAI), there were concerns that the routine protocol might not be sufficient for IA detection. We reviewed the electronic patient charts of all patients with COVID-19 admitted to ICUs between 1 March 2020 and 31 July 2021 for fungal co- or superinfections, comparing four diagnostic algorithms based on different recommendations for the diagnosis of IA (according to EORTC/MSG, BM-AspICU, IAPA and CAPA) to our routine surveillance protocol. We found that out of 252 patients who were admitted to the ICU during the study period, 25 (9.9%) fulfilled the criteria of probable or possible IA of at least one algorithm. The IAPA definitions detected 25 and the CAPA definition 23 probable and 2 possible cases, out of which only 16 were classified as hospital-acquired IA by routine surveillance. In conclusion, adjustment of the routine protocol using a classification system especially designed for respiratory viral illness seems useful for the surveillance of IA in a highly vulnerable patient cohort.

Invasive Fungal Infections Complicating COVID-19: A Narrative Review

Invasive fungal infections (IFIs) can complicate the clinical course of COVID-19 and are associated with a significant increase in mortality, especially in critically ill patients admitted to an intensive care unit (ICU). This narrative review concerns 4099 cases of IFIs in 58,784 COVID-19 patients involved in 168 studies. COVID-19-associated invasive pulmonary aspergillosis (CAPA) is a diagnostic challenge because its non-specific clinical/imaging features and the fact that the proposed clinically diagnostic algorithms do not really apply to COVID-19 patients. Forty-seven observational studies and 41 case reports have described a total of 478 CAPA cases that were mainly diagnosed on the basis of cultured respiratory specimens and/or biomarkers/molecular biology, usually without histopathological confirmation. Candidemia is a widely described secondary infection in critically ill patients undergoing prolonged hospitalisation, and the case reports and observational studies of 401 cases indicate high crude mortality rates of 56.1% and 74.8%, respectively. COVID-19 patients are often characterised by the presence of known risk factors for candidemia such as in-dwelling vascular catheters, mechanical ventilation, and broad-spectrum antibiotics. We also describe 3185 cases of mucormycosis (including 1549 cases of rhino-orbital mucormycosis (48.6%)), for which the main risk factor is a history of poorly controlled diabetes mellitus (>76%). Its diagnosis involves a histopathological examination of tissue biopsies, and its treatment requires anti-fungal therapy combined with aggressive surgical resection/debridement, but crude mortality rates are again high: 50.8% in case reports and 16% in observational studies. The presence of other secondary IFIs usually diagnosed in severely immunocompromised patients show that SARS-CoV-2 is capable of stunning the host immune system: 20 cases of Pneumocystis jirovecii pneumonia, 5 cases of cryptococcosis, 4 cases of histoplasmosis, 1 case of coccidioides infection, 1 case of pulmonary infection due to Fusarium spp., and 1 case of pulmonary infection due to Scedosporium.

Evaluation of the Performance of the Associates of Cape Cod STAT Assay for the Diagnosis of Invasive Fungal Disease in Critical-Care Patients with COVID-19

During the COVID-19 pandemic, there have been increasing reports of invasive fungal disease (IFD) in critical care, where rapid access to (1-3)-β-d-glucan (BDG) testing may have enhanced diagnosis. The potential benefit of rapidly accessible BDG results is limited by local availability of BDG testing, with low demand resulting in testing being performed in specialist centers. The recent release of the Associates of Cape Cod STAT assay provides a simple, low-throughput BDG platform, potentially increasing accessibility. During the pandemic, BDG testing using the Fungitell assay (FA) was a critical component of screening for IFD in our critical care. The performance of the STAT was retrospectively determined through a case-control study of 107 serum samples from critical-care COVID-19 patients with IFD defined according to international guidelines. The STAT demonstrated excellent qualitative (observed agreement, 97.2%; kappa, 0.94) and quantitative (Spearman's coefficient, 0.8962) agreement with the FA. Sample positivity was greater (P < 0.0001) in samples from cases (67.7%) versus controls (6.1%). Using the manufacturer's threshold (≥1.2), sensitivity and specificity for the detection of proven/probable IFD were 67.9% and 93.9%, respectively. Using a lower positivity threshold of ≥0.87 increased sensitivity to 71.4% without compromising specificity. When the STAT BDG index was >2.86, specificity was 100%. The STAT provides a simple, comparable alternative to the FA for detecting BDG. Sensitivity is moderate, and specificity is excellent for the diagnosis of IFD in the critical-care COVID-19 patient. The potential for enhancing access to BDG testing through the uptake of STAT at centers where FA is not available is beneficial, especially during the COVID-19 pandemic.

A Novel Diagnostic Method for Invasive Fungal Disease Using the Factor G Alpha Subunit From Limulus polyphemus

Deaths due to invasive fungal disease (IFD) have been increasing every year. Early and rapid detection is important to reduce the mortality rate associated with IFD. In this study, we explored a novel diagnostic method for detecting IFD, which involves the G Factor α subunit (GFαSub) from Limulus polyphemus. The GFαSub double-sandwich method was developed to detect (1,3)-β-D-glucans in human serum using purified GFαSub and horseradish peroxidase-labeled GFαSub. The GFαSub double-sandwich method and the G test were performed and compared. Using GFαSub sequence analysis, the expression plasmid pET30a-GFαSub252-668 was synthesized, and GFαSub252-668 was expressed and purified via isopropyl-β-d-thiogalactoside induction and nickel-nitrilotriacetic acid affinity. The optimization method was established via the orthogonal method. Using this method, the sera of 36 patients with IFD and 92 volunteers without IFD underwent detection, and the receiver operating characteristic curve of the GFαSub252-668 double-sandwich method was described. The sensitivity and specificity of the GFαSub252-668 double-sandwich method were 91.67 and 82.61%, respectively, and there was good correlation with the G test for the serum specimens of 36 patients with pulmonary IFD (R 2 = 0.7592). In conclusion, our study suggests that the GFαSub252-668 double-sandwich method was satisfactory at detecting IFD cases. This method can be promoted and further developed as a novel method for diagnosing IFD.

Assessment of the Role of 1,3-β-d-Glucan Testing for the Diagnosis of Invasive Fungal Infections in Adults

Detection of 1,3-β-d-glucan (BDG) in serum has been evaluated for its inclusion as a mycological criterion of invasive fungal infections (IFI) according to EORTC and Mycoses Study Group (MSG) definitions. BDG testing may be useful for the diagnosis of both invasive aspergillosis and invasive candidiasis, when interpreted in conjunction with other clinical/radiological signs and microbiological markers of IFI. However, its performance and utility vary according to patient population (hematologic cancer patients, solid-organ transplant recipients, intensive care unit patients) and pretest likelihood of IFI. The objectives of this article are to provide a systematic review of the performance of BDG testing and to assess recommendations for its use and interpretation in different clinical settings.

Diagnostic value of galactomannan test in non-immunocompromised critically ill patients with influenza-associated aspergillosis: data from three consecutive influenza seasons

To explore the diagnostic value of a galactomannan (GM) detection for non-immunocompromised critically ill patients with influenza-associated aspergillosis (IAA). In this retrospective case-control study, we explored the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic (ROC) curve (AUC) of serum and bronchoalveolar lavage fluid (BALF) GM tests by four detection strategies at different detection time points and with different compound modes. In total, 90 patients were evaluated. The AUC values of the second serum GM test, the first and second BALF GM tests, were significantly higher (0.839 (95% CI 0.716 to 0.963), P < 0.01; 0.904 (95% CI 0.820 to 0.988), P < 0.01; 0.827 (95% CI 0.694 to 0.961), P = 0.043) than that of the first serum GM test (0.548 (95% CI 0.377 to 0.718)). We found that at least one positive result on two consecutive serum GM tests (0.719 (95% CI 0.588 to 0.849)) was the best compared with the first positive test (0.419 (95% CI 0.342 to 0.641), P < 0.01) and positives on two consecutive tests (0.636 (95% CI 0.483 to 0.790), P = 0.014). However, there were no differences between those three detection strategies of BALF GM. The BALF GM test might have a better diagnostic value for IAA in the ICU than the serum GM test. A possible cutoff value of 1.0 to 1.3 was set for GM from BALF specimens for IAA. A single serum GM test is not routinely recommended, but at least one positive result on two consecutive tests appeared to be useful.

COVID-19-associated pulmonary aspergillosis: a prospective single-center dual case series

Background

COVID‐19–associated pulmonary aspergillosis (CAPA) has emerged as an invasive fungal disease, often affecting previously immunocompetent, mechanically ventilated, intensive care unit (ICU) patients. Incidence rates of 3.8%–33.3% have been reported depending on the geographic area, with high (47%) mortality.

Objectives

Here, we describe a single‐centre prospective case series with CAPA cases from both the first (March‐May, n = 5/33) and second (mid‐September through mid‐December, n = 8/33) COVID‐19 wave at a 500‐bed teaching hospital in the Netherlands.

Patients/Methods

In the first COVID‐19 wave, a total of 265 SARS‐CoV‐2 PCR‐positive patients were admitted to our hospital of whom 33 needed intubation and mechanical ventilation. In the second wave, 508 SARS‐CoV‐2 PCR‐positive patients were admitted of whom 33 needed mechanical ventilation. Data were prospectively collected.

Results

We found a significant decrease in COVID‐19 patients needing mechanical ventilation in the ICU in the second wave (p < .01). From these patients, however, a higher percentage were diagnosed with CAPA (24.2% vs 15.2%), although not significant (p = .36). All CAPA patients encountered in the second wave received dexamethasone. Mortality between both groups was similarly high (40%–50%). Moreover, we found environmental TR₃₄/L98H azole‐resistant Aspergillus fumigatus isolates in two separate patients.

Conclusions

In this series, 19.7% (n = 13/66) of mechanically ventilated SARS‐CoV‐2 patients were diagnosed with CAPA. In addition, we found a significant reduction in COVID‐19 patients needing mechanical ventilation on the ICU in the second wave. Numbers are too small to determine whether there is a true difference in CAPA incidence in mechanically ventilated patients between the two waves, and whether it could be attributed to dexamethasone SARS‐CoV‐2 therapy.

Aspergillosis Complicating Severe Coronavirus Disease

Aspergillosis complicating severe influenza infection has been increasingly detected worldwide. Recently, coronavirus disease-associated pulmonary aspergillosis (CAPA) has been detected through rapid reports, primarily from centers in Europe. We provide a case series of CAPA, adding 20 cases to the literature, with review of pathophysiology, diagnosis, and outcomes. The syndromes of pulmonary aspergillosis complicating severe viral infections are distinct from classic invasive aspergillosis, which is recognized most frequently in persons with neutropenia and in other immunocompromised persons. Combined with severe viral infection, aspergillosis comprises a constellation of airway-invasive and angio-invasive disease and results in risks associated with poor airway fungus clearance and killing, including virus- or inflammation-associated epithelial damage, systemic immunosuppression, and underlying lung disease. Radiologic abnormalities can vary, reflecting different pathologies. Prospective studies reporting poor outcomes in CAPA patients underscore the urgent need for strategies to improve diagnosis, prevention, and therapy.

Diagnostic Accuracy of Bronchoalveolar Lavage Fluid Galactomannan for Invasive Aspergillosis

Background

The pathogenesis of invasive aspergillosis (IA) is still unknown, but its progression is rapid and mortality rate remains high. Bronchoalveolar lavage fluid (BALF) galactomannan (GM) analysis has been used to diagnose IA. This study is aimed at making an accurate estimate of the whole accuracy of BALF-GM in diagnosing IA.

Methods

After a systematic review of the study, a bivariate meta-analysis was used to summarize the specificity (SPE), the sensitivity (SEN), the positive likelihood ratios (PLR), and the negative likelihood ratios (NLR) of BALF-GM in diagnosing IA. The overall test performance was summarized using a layered summary receiver operating characteristic (SROC) curve. Subgroup analysis was performed to explore the heterogeneity between studies.

Results

A total of 65 studies that are in line with the inclusion criteria were included. The summary estimates of BALF-GM analysis are divided into four categories. The first is the proven+probable vs. possible+no IA, with an SPE, 0.87 (95% CI, 0.85-0.98); SEN, 0.81 (95% CI, 0.76-0.84); PLR, 9.78 (5.78-16.56); and NLR, 0.20 (0.14-0.29). The AUC was 0.94. The BALF-GM test for proven+probable vs. no IA showed SPE, 0.88 (95% CI, 0.87-0.90); SEN, 0.82 (95% CI, 0.78-0.85); PLR, 6.56 (4.93-8.75); and NLR, 0.24 (0.17-0.33). The AUC was 0.93. The BALF-GM test for proven+probable+possible vs. no IA showed SPE, 0.82 (95% CI, 0.79-0.95); SEN, 0.59 (95% CI, 0.55-0.63); PLR, 3.60 (2.07-6.25); and NLR, 0.31 (0.15-0.61). The AUC was 0.86. The analyses for others showed SPE, 0.85 (95% CI, 0.83-0.87); SEN, 0.89 (95% CI, 0.86-0.91); PLR, 6.91 (4.67-10.22); and NLR, 0.18 (0.13-0.26). The AUC was 0.94.

Conclusions

The findings of this BALF-GM test resulted in some impact on the diagnosis of IA. The BALF-GM assay is considered a method for diagnosing IA with high SEN and SPE. However, the patients' underlying diseases may affect the accuracy of diagnosis. When the cutoff is greater than 1, the sensitivity will be higher.

Confronting and mitigating the risk of COVID-19 associated pulmonary aspergillosis

The coronavirus disease 2019 (COVID-19) virus caused a wide spectrum of disease in healthy individuals, as well as those with common comorbidities [1]. Severe COVID-19 is characterised by acute respiratory distress syndrome (ARDS) secondary to viral pneumonitis, treatment of which may require mechanical ventilation or extracorporeal membrane oxygenation [2]. Clinicians are alert to the possibility of bacterial co-infection as a complication of lower respiratory tract viral infection; for example, a recent review found that 72% of patients with COVID-19 received antimicrobial therapy [3]. However, the risk of fungal co-infection, in particular COVID-19 associated pulmonary aspergillosis (CAPA), remains underappreciated.

Cases of COVID-19 associated pulmonary aspergillosis (CAPA) are being increasingly reported and physicians treating patients with COVID-19-related lung disease need to actively consider these fungal co-infections https://bit.ly/3feuGsQ

A national strategy to diagnose COVID-19 associated invasive fungal disease in the ICU

Background

Fungal co-infection is a recognised complication of respiratory virus infections, increasing morbidity and mortality, but can be readily treated if diagnosed early. An increasing number of small studies describing aspergillosis in COVID-19 patients with severe respiratory distress are being reported, but comprehensive data is lacking. The aim of this study was to determine the incidence, risk factors and impact of invasive fungal disease in adult COVID-19 patients with severe respiratory distress.

Methods

An evaluation of a national, multi-centre, prospective cohort evaluation of an enhanced testing strategy to diagnose invasive fungal disease in COVID-19 intensive care patients. Results were used to generate a mechanism to define aspergillosis in future COVID-19 patients.

Results

One-hundred and thirty-five adults (median age: 57, M/F: 2·2/1) were screened. The incidence was 26.7% (14.1% aspergillosis, 12·6% yeast infections). The overall mortality rate was 38%; 53% and 31% in patients with and without fungal disease, respectively (P: 0.0387). The mortality rate was reduced by the use of antifungal therapy (Mortality: 38·5% in patients receiving therapy versus 90% in patients not receiving therapy (P: 0.008). The use of corticosteroids (P: 0.007) and history of chronic respiratory disease (P: 0.05) increased the likelihood of aspergillosis.

Conclusions

Fungal disease occurs frequently in critically ill, mechanically ventilated COVID-19 patients. The survival benefit observed in patients receiving antifungal therapy implies that the proposed diagnostic and defining criteria are appropriate. Screening using a strategic diagnostic approach and antifungal prophylaxis of patients with risk factors will likely enhance the management of COVID-19 patients.

(1→3)-β-D-glucan testing for the detection of invasive fungal infections in immunocompromised or critically ill people

BACKGROUND

Invasive fungal infections (IFIs) are life-threatening opportunistic infections that occur in immunocompromised or critically ill people. Early detection and treatment of IFIs is essential to reduce morbidity and mortality in these populations. (1→3)-β-D-glucan (BDG) is a component of the fungal cell wall that can be detected in the serum of infected individuals. The serum BDG test is a way to quickly detect these infections and initiate treatment before they become life-threatening. Five different versions of the BDG test are commercially available: Fungitell, Glucatell, Wako, Fungitec-G, and Dynamiker Fungus.

OBJECTIVES

To compare the diagnostic accuracy of commercially available tests for serum BDG to detect selected invasive fungal infections (IFIs) among immunocompromised or critically ill people.

SEARCH METHODS

We searched MEDLINE (via Ovid) and Embase (via Ovid) up to 26 June 2019. We used SCOPUS to perform a forward and backward citation search of relevant articles. We placed no restriction on language or study design.

SELECTION CRITERIA

We included all references published on or after 1995, which is when the first commercial BDG assays became available. We considered published, peer-reviewed studies on the diagnostic test accuracy of BDG for diagnosis of fungal infections in immunocompromised people or people in intensive care that used the European Organization for Research and Treatment of Cancer (EORTC) criteria or equivalent as a reference standard. We considered all study designs (case-control, prospective consecutive cohort, and retrospective cohort studies). We excluded case studies and studies with fewer than ten participants. We also excluded animal and laboratory studies. We excluded meeting abstracts because they provided insufficient information.

DATA COLLECTION AND ANALYSIS

We followed the standard procedures outlined in the Cochrane Handbook for Diagnostic Test Accuracy Reviews. Two review authors independently screened studies, extracted data, and performed a quality assessment for each study. For each study, we created a 2 × 2 matrix and calculated sensitivity and specificity, as well as a 95% confidence interval (CI). We evaluated the quality of included studies using the Quality Assessment of Studies of Diagnostic Accuracy-Revised (QUADAS-2). We were unable to perform a meta-analysis due to considerable variation between studies, with the exception of Candida, so we have provided descriptive statistics such as receiver operating characteristics (ROCs) and forest plots by test brand to show variation in study results.

MAIN RESULTS

We included in the review 49 studies with a total of 6244 participants. About half of these studies (24/49; 49%) were conducted with people who had cancer or hematologic malignancies. Most studies (36/49; 73%) focused on the Fungitell BDG test. This was followed by Glucatell (5 studies; 10%), Wako (3 studies; 6%), Fungitec-G (3 studies; 6%), and Dynamiker (2 studies; 4%). About three-quarters of studies (79%) utilized either a prospective or a retrospective consecutive study design; the remainder used a case-control design. Based on the manufacturer's recommended cut-off levels for the Fungitell test, sensitivity ranged from 27% to 100%, and specificity from 0% to 100%. For the Glucatell assay, sensitivity ranged from 50% to 92%, and specificity ranged from 41% to 94%. Limited studies have used the Dynamiker, Wako, and Fungitec-G assays, but individual sensitivities and specificities ranged from 50% to 88%, and from 60% to 100%, respectively. Results show considerable differences between studies, even by manufacturer, which prevented a formal meta-analysis. Most studies (32/49; 65%) had no reported high risk of bias in any of the QUADAS-2 domains. The QUADAS-2 domains that had higher risk of bias included participant selection and flow and timing.

AUTHORS' CONCLUSIONS

We noted considerable heterogeneity between studies, and these differences precluded a formal meta-analysis. Because of wide variation in the results, it is not possible to estimate the diagnostic accuracy of the BDG test in specific settings. Future studies estimating the accuracy of BDG tests should be linked to the way the test is used in clinical practice and should clearly describe the sampling protocol and the relationship of time of testing to time of diagnosis.

Azole-Resistant COVID-19-Associated Pulmonary Aspergillosis in an Immunocompetent Host: A Case Report

COVID-19-associated pulmonary aspergillosis (CAPA) is a recently described disease entity affecting patients with severe pulmonary abnormalities treated in intensive care units. Delays in diagnosis contribute to a delayed start of antifungal therapy. In addition, the emergence of resistance to triazole antifungal agents puts emphasis on early surveillance for azole-resistant Aspergillus species. We present a patient with putative CAPA due to Aspergillus fumigatus with identification of a triazole-resistant isolate during therapy. We underline the challenges faced in the management of these cases, the importance of early diagnosis and need for surveillance given the emergence of triazole resistance.

Cell wall polysaccharides from pathogenic fungi for diagnosis of fungal infectious disease

Invasive fungal diseases are associated with significant morbidity and mortality, particularly in immunocompromised individuals. Early and accurate diagnosis is crucial for effective treatment. Despite traditional methods such as microbiological culture, histopathology, radiology and direct microscopy are available, antigen/antibody-based diagnostics are emerging for diagnosis of invasive fungal infections (IFI). Fungal cell wall is a unique structure composed of polysaccharides that are well correlated with fungal burden during fungal infections. Based on this feature, cell wall polysaccharides have been explored as antigens in IFIs diagnostics such as the galactomannan assay, mannan test, β-glucan assay and cryptococcal CrAg test. Herein, we provide an overview on the cell wall polysaccharides from three opportunistic pathogens: Aspergillus fumigatus, Candida albicans and Cryptococcus neoformans, and their applications for IFIs diagnosis. The clinical outcome of newly developed cell wall polysaccharides-based diagnostics is also discussed.

Galactomannan detection in broncho-alveolar lavage fluid for invasive aspergillosis in immunocompromised patients

BACKGROUND

Invasive aspergillosis (IA) is a life-threatening opportunistic mycosis that occurs in some people with a compromised immune system. The serum galactomannan enzyme-linked immunosorbent assay (ELISA) rapidly gained widespread acceptance as part of the diagnostic work-up of a patient suspected of IA. Due to its non-invasive nature, it can be used as a routine screening test. The ELISA can also be performed on bronchoalveolar lavage (BAL), allowing sampling of the immediate vicinity of the infection. The invasive nature of acquiring BAL, however, changes the role of the galactomannan test significantly, for example by precluding its use as a routine screening test.

OBJECTIVES

To assess the diagnostic accuracy of galactomannan detection in BAL for the diagnosis of IA in people who are immunocompromised, at different cut-off values for test positivity, in accordance with the Cochrane Diagnostic Test Accuracy Handbook.

SEARCH METHODS

We searched three bibliographic databases including MEDLINE on 9 September 2016 for aspergillosis and galactomannan as text words and subject headings where appropriate. We checked reference lists of included studies for additional studies.

SELECTION CRITERIA

We included cohort studies that examined the accuracy of BAL galactomannan for the diagnosis of IA in immunocompromised patients if they used the European Organization for Research and Treatment of Cancer/Invasive Fungal Infections Cooperative Group and the National Institute of Allergy and Infectious Diseases Mycoses Study Group (EORTC/MSG) classification as reference standard.

DATA COLLECTION AND ANALYSIS

Two review authors assessed study quality and extracted data. Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) was used for quality assessment.

MAIN RESULTS

We included 17 studies in our review. All studies except one had a high risk of bias in two or more domains. The diagnostic performance of an optical density index (ODI) of 0.5 as cut-off value was reported in 12 studies (with 1123 patients). The estimated sensitivity was 0.88 (95% confidence interval (CI) 0.75 to 1.00) and specificity 0.81 (95% CI 0.71 to 0.91). The performance of an ODI of 1.0 as cut-off value could be determined in 11 studies (with 648 patients). The sensitivity was 0.78 (95% CI 0.61 to 0.95) and specificity 0.93 (95% CI 0.87 to 0.98). At a cut-off ODI of 1.5 or higher, the heterogeneity in specificity decreased significantly and was invariably >90%.

AUTHORS' CONCLUSIONS

The optimal cut-off value depends on the local incidence and clinical pathway. At a prevalence of 12% a hypothetical population of 1000 patients will consist of 120 patients with IA. At a cut-off value of 0.5 14 patients with IA will be missed and there will be 167 patients incorrectly diagnosed with IA. If we use the test at a cut-off value of 1.0, we will miss 26 patients with IA. And there will be 62 patients incorrectly diagnosed with invasive aspergillosis. The populations and results were very heterogeneous. Therefore, interpretation and extrapolation of these results has to be performed with caution. A test result of 1.5 ODI or higher appears a strong indicator of IA.

PCR with electrospray ionization-mass spectrometry on bronchoalveolar lavage for detection of invasive mold infections in hematological patients

Invasive mold infections are life-threatening complications in patients with hematological malignancies. Conventional microbiological methods for diagnosing invasive pulmonary mold infections have low sensitivity, and molecular methods are being developed. Detection of molds using PCR with a narrow spectrum has been reported, but data with broad-spectrum PCR are lacking. In this study, the diagnostic performance and utility of a broad-spectrum PCR (broad-spectrum PCR with subsequent electrospray ionization-mass spectrometry, PCR/ESI-MS) for detection of molds in bronchoalveolar lavage (BAL) in 27 hematological patients with a new pulmonary infiltrate was analyzed. Using the revised EORTC/MSG criteria, PCR/ESI-MS was the only positive microbiological test in patients with proven invasive mold infection (n = 2) and correctly identified all cases of probable invasive pulmonary aspergillosis (n = 5). In patients with a possible invasive mold infection (n = 5), PCR/ESI-MS was positive in three patients. Mucorales was identified with PCR/ESI-MS in four patients that were all culture negative. The PCR/ESI-MS results had a clinical impact on antifungal therapy in 12 (44%) of the patients: modification of treatment in 6 (22%) patients and discontinuation in 6 (22%) patients. This study provides proof of concept that routine use of a broad-spectrum PCR for molds in bronchoalveolar lavage in immunocompromised patients is sensitive, fast, and has an impact on clinical decision-making.

Strategies for Antimicrobial Stewardship in Solid Organ Transplant Recipients

Complications of antimicrobial therapy, such as multidrug-resistant organisms and Clostridium difficile, commonly affect solid-organ transplant recipients and have been associated with graft loss and mortality. Although opportunities are abundant, antimicrobial stewardship practices guiding appropriate therapy have been infrequently reported in transplant patients. A patient-centered, multidisciplinary structure, using established antimicrobial optimization principles, is needed to create nuanced approaches to protect patients and antimicrobials and improve outcomes.

Invasive pulmonary aspergillosis in patients with solid tumours: risk factors and predictors of clinical outcomes

BACKGROUND

The characteristics and management of invasive pulmonary aspergillosis (IPA) in patients with hematologic malignancies are well known, but IPA in patients with solid tumours is not well described.

METHODS

We retrospectively reviewed all Aspergillus-positive cultures at a tertiary cancer center during 2004-2017. We identified 101 patients with IPA and solid tumours. We analyzed the association between clinical features and treatment and 12-week mortality and response to antifungal therapy.

RESULTS

Fifty-one patients had lung cancer, 77 had underlying lung disease, 47 received chest radiation and 33 had chronic obstructive pulmonary disease. Aspergillus fumigatus was the most common type isolated (71%); 68 patients (70%) were treated with voriconazole monotherapy. Independent risk factors for 12-week mortality included receiving steroids within 30 days of diagnosis (hazard ratio 2.2, 95% confidence interval [CI]: 1.1-4.6; p = .03) and chest radiotherapy (hazard ratio 2.6, 95% CI: 1.2-5.5; p = .01). In multivariate analysis, a positive fungal stain was associated with lower odds of a successful response (odds ratio 0.2; 95% CI: 0.05-0.75; p = .02), whereas voriconazole treatment was associated with higher odds (odds ratio 10.1; 95% CI: 2.1-48.5; p < .01).

CONCLUSIONS

IPA should be considered in patients with solid tumours, particularly those with underlying lung disease. Key messages Invasive pulmonary aspergillosis should be considered in patients with solid tumours, particularly those with underlying lung disease, lung cancer and those who received chest radiotherapy. Most of the patients with invasive pulmonary aspergillosis and solid tumours presented with nonspecific symptoms and signs as well as nonspecific CT findings. Unlike patients with hematologic malignancies, fever and hemoptysis were not predominant symptoms and the classical halo sign and the air-crescent sign were not described. Independent risk factors for 12-week mortality included receiving steroids within 30 days of diagnosis and chest radiotherapy. In multivariate analysis, a positive fungal stain was associated with lower odds of a successful response to antifungal therapy, whereas voriconazole treatment was associated with higher odds.

Detection of invasive pulmonary aspergillosis in critically ill patients by combined use of conventional culture, galactomannan, 1-3-beta-D-glucan and Aspergillus specific nested polymerase chain reaction in a prospective pilot study

Invasive pulmonary aspergillosis (IPA) is an emerging and life-threatening infectious disease in patients admitted to the intensive care unit (ICU). Most diagnostic studies are conducted in hematological patients and results cannot readily be transferred to ICU patients lacking classical host factors. In a multicenter, prospective clinical trial including 44 ICU patients, hematological (n = 14) and non-hematological patients (n = 30), concurrent serum and bronchoalveolar lavage (BAL) samples were analyzed by conventional culture, galactomannan (GM), 1-3-beta-D-glucan (BDG) as well as an Aspergillus specific nested polymerase chain reaction (PCR). Nine patients (20%) had putative IPA according to AspICU classification. GM and PCR showed superior performance in BAL with sensitivity/specificity of 56%/94% and 44%/94% compared to 33%/97% and 11%/94% in serum. Despite better sensitivity of 89%, BDG showed poor specificity of only 31% (BAL) and 26% (serum). Combination of GM and PCR (BAL) with BDG (serum) resulted in 100% sensitivity, but also reduced specificity to 23%. Whereas mean GM levels were significantly higher in hematological patients BDG and PCR did not differ between hematological and non-hematological patients. Under present clinical conditions test combinations integrating both BAL and blood samples are advantageous. BDG might best serve as possible indicator for ruling out IPA.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01695499. First posted: September 28, 2012, last update posted: May 8, 2017.

Diagnostic value of serum galactomannan, (1,3)-β-d-glucan, and Aspergillus fumigatus-specific IgA and IgG assays for invasive pulmonary aspergillosis in non-neutropenic patients

Detection of serum galactomannan (GM) and (1,3)-β-d-glucan (BG) is considered useful for non-culture diagnosis of invasive pulmonary aspergillosis (IPA) in neutropenic patients. Only few studies evaluated these seromarkers in non-neutropenic patients suspected of having IPA. The aim of this study was to evaluate both tests together with the Aspergillus fumigatus-specific serum IgG and IgA (IgAG) test for serological IPA diagnosis in non-neutropenic patients. Sera from 87 patients suspected of having IPA were retrospectively analysed. Patients were categorised into groups of proven IPA (n = 10), putative IPA (n = 31) and non-IPA colonisation (n = 46). When the GM, BG and IgAG assays were used for patients included in the study, the sensitivity/specificity/positive predictive value (PPV)/negative predictive value (NPV) were 48.8%/91.3%/83.3%/66.7%, 82.9%/73.9%/73.9%/82.9% and 75.6%/95.7%/93.9%/81.5%, respectively. Thus, the highest specificity and PPV were confirmed for the IgAG assay. Improvements in the sensitivity and NPV were achieved by "at least one positive" analysis with the GM and BG assays, with the sensitivity/specificity/PPV/NPV values being 85.0%/69.6%/71.4%/84.2%. Nevertheless, the highest sensitivity and NPV were achieved by the "at least one positive" analysis combining the GM, BG and IgAG tests (97.6% and 96.8%, respectively). The involvement of the IgAG assay could improve IPA diagnosis in non-neutropenic patients by increasing the sensitivity and NPV when combined with the GM or BG assays. Furthermore, improvement was achieved by combining the GM, BG and IgAG assays using the "at least one positive test" strategy, especially if doubt exists.

Feasibility and applicability of antimicrobial stewardship in immunocompromised patients

PURPOSE OF REVIEW

Antimicrobial stewardship is the primary intervention in the battle against antimicrobial resistance, but clinicians do not always apply many key antimicrobial stewardship principles to patients with significant immune defects due to lack of data and fear of bad outcomes. We review evidence regarding the application of stewardship principles to immunocompromised patients, with a focus on solid organ and hematopoietic stem cell transplant recipients.

RECENT FINDINGS

Antimicrobial stewardship programs (ASPs), targeting immunocompromised patient populations such as oncology and transplant, are gaining traction. Emerging literature suggests that several stewardship interventions can be adapted to immunocompromised hosts and improve antimicrobial utilization, but data supporting improved outcomes is very limited.

SUMMARY

The application of antimicrobial stewardship principles to immunocompromised patients is feasible, necessary, and urgent. As antimicrobial stewardship programs gain momentum across a diverse range of healthcare settings more immunocompromised patients will fall under their purview. It is imperative that centers applying antimicrobial stewardship principles share their experience and establish collaborative research efforts to advance our knowledge base in applying antimicrobial stewardship initiatives to immunocompromised host populations, both in terms of programmatic success and patient outcomes.

Effect of involved Aspergillus species on galactomannan in bronchoalveolar lavage of patients with invasive aspergillosis

PURPOSE

The detection of galactomannan (GM) in bronchoalveolar lavage (BAL) fluid is an important surrogate marker for the early diagnosis and therapeutic monitoring of invasive aspergillosis (IA), regardless of the involved species of Aspergillus. Here, we utilized the Platelia Aspergillus GM enzyme immunoassay (Bio-Rad) to evaluate the GM index in BAL fluid samples from patients with proven, probable or putative IA due to Aspergillusflavus versus Aspergillusfumigatus.

METHODOLOGY

In a prospective study between 2009 and 2015, 116 BAL samples were collected from suspected IA patients referred to two university hospitals in Tehran, Iran.

KEY FINDINGS

According to European Organization for Research and Treatment of Cancer and Mycoses Study Group and Blot criteria, 35 patients were classified as IA patients, of which 33 cases tested positive for GM above 0.5 and, among these patients, 22 had a GM index ≥1. Twenty-eight were culture positive for A. flavus and seven for A. fumigatus. The GM index for A. flavus cases was between 0.5-6.5 and those of A. fumigatus ranged from 1 to 6.5. The sensitivity and specificity of a GM index ≥0.5 in cases with A. flavus were 86 and 88 % and for A. fumigatus patients were 100 and 73 %, respectively.

CONCLUSION

Overall, the mean GM index in patients with A. fumigatus (3.1) was significantly higher than those of A. flavus (1.6; P-value=0.031) and the sensitivity of GM lower for A. flavus when compared to A. fumigatus. This finding has implications for diagnosis in hospitals and countries with a high proportion of A. flavus infections.