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

Antifungal Activity of NP20 Derived from Amphioxus Midkine/Pleiotrophin Homolog Against Aspergillus niger and Aspergillus fumigatus

With the emergence of antifungal resistance, systematic infections with Aspergillus are becoming the major cause of the clinical morbidity. The development of novel antifungal agents with high efficacy, low drug tolerance, and few side effects is urgent. In response to that need, we have identified NP20. Here we demonstrate clearly that NP20 has antifungal activity, capable of killing the spores of Aspergillus niger and Aspergillus fumigatus as well as causing direct damage to the surface, membrane, cytoplasm, organelle, and nucleus of the fungal spores. Interestingly, NP20 is active under temperature stress and a wide range of pH. Subsequently, MTT assay, assay for binding of NP20 to fungal cell wall components, membrane depolarization assay, confocal microscopy, ROS assay, DNA replication, and protein synthesis assay are performed to clarify the mechanisms underlying NP20 against Aspergillus. The results show that NP20 can bind with and pass through the fungal cell wall, and then interfere with the lipid membrane. Moreover, NP20 can induce intracellular ROS production, DNA fragmentation, and protein synthesis inhibition of the fungal cells. These together indicate that NP20 is a novel antifungal peptide, which has considerable potential for future development as novel peptide antibiotics against Aspergillus.

Association between early diagnosis of and inpatient mortality from invasive pulmonary aspergillosis among patients without immunocompromised host factors: a nationwide observational study

OBJECTIVES

The incidence of invasive pulmonary aspergillosis (IPA) among patients without immunocompromised host factors (ICHF) has been described extensively. However, its diagnosis remains challenging. To date, no study has statistically confirmed the efficacy of early IPA diagnosis in patients without ICHF.

METHODS

We conducted a cross-sectional study on mortality from IPA among patients without ICHF, using the Japanese Diagnosis Procedure Combination National Inpatient Database (April 2014-March 2018). The early diagnosis group was defined according to antifungal therapy initiation within 7 days of hospital admission. The delayed diagnosis group was defined according to antifungal therapy initiation between 8 and 28 days of the hospitalization. Associations were estimated using multivariate logistic regression.

RESULTS

A total of 423 patients were registered (early diagnosis group, n = 262, 62%). The early diagnosis group had a lower mortality rate (30%) than the delayed diagnosis group (42%). The early diagnosis group that was treated with voriconazole was associated with lower odds of mortality (odds ratio 0.55, 95% confidence interval 0.31-0.99, P = 0.047). An age of ≥65 years and mechanical ventilation were associated with a higher mortality rate.

CONCLUSION

Early diagnosis along with optimal antifungal treatment are crucial for achieving favorable outcomes among patients with IPA without ICHF.

Mechanistic Basis of Super-Infection: Influenza-Associated Invasive Pulmonary Aspergillosis

Influenza infection is a risk factor for invasive pulmonary aspergillosis in both immunocompetent and immunocompromised hosts. The purpose of this review is to highlight the epidemiology of influenza-associated invasive pulmonary aspergillosis and the mechanistic studies that have been performed to delineate how influenza increases susceptibility to this invasive fungal infection.

Invasive Aspergillus outbreak in inhalation injury: a case presentation and literature review

Background

Invasive pulmonary aspergillosis often occurs in patients with poor immune function, who abuse steroids or broad-spectrum antibiotics, or who use intravenous drugs. Among the Aspergillus genus of pulmonary infection, Aspergillus fumigatus is the most important pathogen, followed by Aspergillus flavus, Aspergillus niger, and Aspergillus terreus. Inhalation injury complicated by Aspergillus infection has atypical clinical manifestations. Diagnosis is difficult, and it is easy to make mistakes in treatment. Moreover, there are few cases of burn inhalation injury complicated with pulmonary Aspergillus.

Case presentation

We report a case of severe burns combined with severe inhalation injury, early pulmonary aspergillosis, and severe respiratory failure due to treatment discontinuation. Through analyzing the processes of diagnosis and treatment in the present case and performing a literature review, we explore feasible diagnosis and treatment plans.

Conclusions

Early application of a variety of diagnostic measures can be used to identify Aspergillus infection, and targeted anti-infection treatment is likely to reverse a severe adverse prognosis.

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.

Retrospective Evaluation of Risk Factors for Invasive Candida Infections in a Medical Intensive Care Unit

Objective

We aimed to detect the risk factors for invasive candida infections by evaluating the fungal strains cultivated from samples taken in a medical intensive care unit (ICU).

Materials and Methods

We investigated fungal growths between January 1, 2016, and December 1, 2018, retrospectively. All reported fungal growths and demographic characteristics, clinical features, treatments and outcomes of the patients with fungal growths were recorded.

Results

Fungal growths were reported from 384 different samples obtained from 179 ICU patients. The most common strain was determined to be C. albicans (47.9%).The incidence of non-albicansCandida strains was increased over the years (2016 - 44%, 2017 - 52.5%, 2018 - 49%), most significantly C. glabrata (7.7% to 14.6%). The most common strain was C. parapsilosis (57.9%) in patients with candidemia, and infection was more severe among them. Fluconazole resistance was rare. When patients with and without fungal growth were compared, a significant difference was found between groups in terms of age, acute physiology and chronic health evaluation II (APACHE II) score, length of ICU and hospital stay, ICU and hospital mortality (p<0.001, p =0.011, p<0.001, p=0.031, p =0.016). Candida score was significantly higher in candidemic patients (3.0 vs 0.0 p<0.001).

Conclusion

Among fungal growths in samples from critically ill patients, the incidence of non-albicans Candida strains was gradually increasing. Older age, higher APACHE II score, and longer hospital and ICU stay were associated with fungal growths.

Water-Soluble Nystatin and Derivative

Fungal infections are increasingly causing more morbidity and mortality, especially for immunocompromised people. In recent years, there is growing evidence that new medicine-resistant fungal strains are posing added challenges in the clinic. Nystatin is a known antifungal from the polyene family. Due to Nystatin limited solubility and high toxicity, it is used mainly to treat oral and dermal fungal infections. In search for new Nystatin derivatives and formulations, we obtained amide derivatives and a deoxycholate formulation that were not described previously for this compound. Furthermore, we tested the potency of the derivatives and formulation by the USP(81) method and minimum inhibitory concentration of Candida albicans and Aspergillus niger. Additionally, the in vitro toxicity and stability were tested, and it was found that the ethanol amide derivative of Nystatin was fully water-soluble (up to 100 mg/mL) with the same potency of Nystatin but with 13.5 times lower toxicity. The ethanol amide derivative of Nystatin is a promising candidate for future drug development.

Invasive Pulmonary Aspergillosis in Hospital and Ventilator-Associated Pneumonias

Pneumonia is the commonest nosocomial infection complicating hospital stay, with both non-ventilated hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) occurring frequently amongst patients in intensive care. Aspergillus is an increasingly recognized pathogen amongst patients with HAP and VAP, and is associated with significantly increased mortality if left untreated.Invasive pulmonary aspergillosis (IPA) was originally identified in patients who had been profoundly immunosuppressed, however, this disease can also occur in patients with relative immunosuppression such as critically ill patients in intensive care unit (ICU). Patients in ICU commonly have several risk factors for IPA, with the inflamed pulmonary environment providing a niche for aspergillus growth.An understanding of the true prevalence of this condition amongst ICU patients, and its specific rate in patients with HAP or VAP is hampered by difficulties in diagnosis. Establishing a definitive diagnosis requires tissue biopsy, which is seldom practical in critically ill patients, so imperfect proxy measures are required. Clinical and radiological findings in ventilated patients are frequently non-specific. The best-established test is galactomannan antigen level in bronchoalveolar lavage fluid, although this must be interpreted in the clinical context as false positive results can occur. Acknowledging these limitations, the best estimates of the prevalence of IPA range from 0.3 to 5% amongst all ICU patients, 12% amongst patients with VAP and 7 to 28% amongst ventilated patients with influenza.Antifungal triazoles including voriconazole are the first-line therapy choice in most cases. Amphotericin has excellent antimold coverage, but a less advantageous side effect profile. Echinocandins are less effective against IPA, but may play a role in rescue therapy, or as an adjuvant to triazole therapy.A high index of suspicion for IPA should be maintained when investigating patients with HAP or VAP, especially when they have specific risk factors or are not responding to appropriate empiric antibacterial therapy.

Heterogeneity in the transcriptional response of the human pathogen Aspergillus fumigatus to the antifungal agent caspofungin

Aspergillus fumigatus is the main causative agent of invasive pulmonary aspergillosis (IPA), a severe disease that affects immunosuppressed patients worldwide. The fungistatic drug caspofungin (CSP) is the second line of therapy against IPA but has increasingly been used against clinical strains that are resistant to azoles, the first line antifungal therapy. In high concentrations, CSP induces a tolerance phenotype with partial reestablishment of fungal growth called CSP paradoxical effect (CPE), resulting from a change in the composition of the cell wall. An increasing number of studies has shown that different isolates of A. fumigatus exhibit phenotypic heterogeneity, including heterogeneity in their CPE response. To gain insights into the underlying molecular mechanisms of CPE response heterogeneity, we analyzed the transcriptomes of two A. fumigatus reference strains, Af293 and CEA17, exposed to low and high CSP concentrations. We found that there is a core transcriptional response that involves genes related to cell wall remodeling processes, mitochondrial function, transmembrane transport, and amino acid and ergosterol metabolism, and a variable response related to secondary metabolite (SM) biosynthesis and iron homeostasis. Specifically, we show here that the overexpression of a SM pathway that works as an iron chelator extinguishes the CPE in both backgrounds, whereas iron depletion is detrimental for the CPE in Af293 but not in CEA17. We next investigated the function of the transcription factor CrzA, whose deletion was previously shown to result in heterogeneity in the CPE response of the Af293 and CEA17 strains. We found that CrzA constitutively binds to and modulates the expression of several genes related to processes involved in CSP tolerance and that crzA deletion differentially impacts the SM production and growth of Af293 and CEA17. As opposed to the ΔcrzACEA17 mutant, the ΔcrzAAf293 mutant fails to activate cell wall remodeling genes upon CSP exposure, which most likely severely affects its macrostructure and extinguishes its CPE. This study describes how heterogeneity in the response to an antifungal agent between A. fumigatus strains stems from heterogeneity in the function of a transcription factor and its downstream target genes.

Invasive pulmonary aspergillosis among intubated patients with SARS-CoV-2 or influenza pneumonia: a European multicenter comparative cohort study

BACKGROUND

Recent multicenter studies identified COVID-19 as a risk factor for invasive pulmonary aspergillosis (IPA). However, no large multicenter study has compared the incidence of IPA between COVID-19 and influenza patients.

OBJECTIVES

To determine the incidence of putative IPA in critically ill SARS-CoV-2 patients, compared with influenza patients.

METHODS

This study was a planned ancillary analysis of the coVAPid multicenter retrospective European cohort. Consecutive adult patients requiring invasive mechanical ventilation for > 48 h for SARS-CoV-2 pneumonia or influenza pneumonia were included. The 28-day cumulative incidence of putative IPA, based on Blot definition, was the primary outcome. IPA incidence was estimated using the Kalbfleisch and Prentice method, considering extubation (dead or alive) within 28 days as competing event.

RESULTS

A total of 1047 patients were included (566 in the SARS-CoV-2 group and 481 in the influenza group). The incidence of putative IPA was lower in SARS-CoV-2 pneumonia group (14, 2.5%) than in influenza pneumonia group (29, 6%), adjusted cause-specific hazard ratio (cHR) 3.29 (95% CI 1.53-7.02, p = 0.0006). When putative IPA and Aspergillus respiratory tract colonization were combined, the incidence was also significantly lower in the SARS-CoV-2 group, as compared to influenza group (4.1% vs. 10.2%), adjusted cHR 3.21 (95% CI 1.88-5.46, p < 0.0001). In the whole study population, putative IPA was associated with significant increase in 28-day mortality rate, and length of ICU stay, compared with colonized patients, or those with no IPA or Aspergillus colonization.

CONCLUSIONS

Overall, the incidence of putative IPA was low. Its incidence was significantly lower in patients with SARS-CoV-2 pneumonia than in those with influenza pneumonia. Clinical trial registration The study was registered at ClinicalTrials.gov, number NCT04359693 .

Mortality outcomes associated with invasive aspergillosis among acute exacerbation of chronic obstructive pulmonary disease patient population

BACKGROUND

Literature regarding trends of mortality, and complications of aspergillosis infection among patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is limited.

METHODS

Data from the National Readmissions Database (NRD) that constitutes 49.1% of the stratified sample of all hospitals in the United States (US), representing more than 95% of the national population were analyzed for hospitalizations with aspergillosis among AECOPD. Predictors and trends related to aspergillosis in AECOPD were evaluated. A Linear p-trend was used to assess the trends.

RESULTS

Out of the total 7,282,644 index hospitalizations for AECOPD (mean age 69.17 ± 12.04years, 55.3% females), 8209 (11.2/10,000) with primary diagnosis of invasive aspergillosis were recorded in the NRD for 2013-2018. Invasive aspergillosis was strongly associated with mortality (OR 4.47, 95%CI 4.02-4.97, p < 0.001) among AECOPD patients. Malignancy and organ transplant status were predominant predictors of developing aspergillosis among AECOPD patients. The IA-AECOPD group had higher rates of multi-organ manifestations including ACS (3.7% vs 0.44%; p-value0.001), AF (20% vs 18.4%; p-value0.001), PE (4.79% vs1.87%; p-value0.001), AKI (22.3% vs17.5%; p-value0.001), ICU admission (16.5% vs11.9%; p-value0.001), and MV (22.3% vs7.31%; p-value0.001) than the AECOPD group. The absolute yearly trend for mortality of aspergillosis was steady (linear p-trend 0.22) while the yearly rate of IA-AECOPD had decreased from 15/10,000 in 2013 to 9/10,000 in 2018 (linear p-trend 0.02).

INTERPRETATION

Aspergillosis was related with high mortality among AECOD hospitalizations. There has been a significant improvement in the yearly rates of aspergillosis while the mortality trend was steady among aspergillosis subgroups. Improved risk factor management through goal-directed approach may improve clinical outcomes.

Dynamic optimization reveals alveolar epithelial cells as key mediators of host defense in invasive aspergillosis

Aspergillus fumigatus is an important human fungal pathogen and its conidia are constantly inhaled by humans. In immunocompromised individuals, conidia can grow out as hyphae that damage lung epithelium. The resulting invasive aspergillosis is associated with devastating mortality rates. Since infection is a race between the innate immune system and the outgrowth of A. fumigatus conidia, we use dynamic optimization to obtain insight into the recruitment and depletion of alveolar macrophages and neutrophils. Using this model, we obtain key insights into major determinants of infection outcome on host and pathogen side. On the pathogen side, we predict in silico and confirm in vitro that germination speed is an important virulence trait of fungal pathogens due to the vulnerability of conidia against host defense. On the host side, we found that epithelial cells, which have been underappreciated, play a role in fungal clearance and are potent mediators of cytokine release. Both predictions were confirmed by in vitro experiments on established cell lines as well as primary lung cells. Further, our model affirms the importance of neutrophils in invasive aspergillosis and underlines that the role of macrophages remains elusive. We expect that our model will contribute to improvement of treatment protocols by focusing on the critical components of immune response to fungi but also fungal virulence traits.

Aspergillosis: Emerging risk groups in critically ill patients

Information on invasive aspergillosis (IA) and other invasive filamentous fungal infections is limited in non-neutropenic patients admitted to the intensive care unit (ICU) and presenting with no classic IA risk factors. This review is based on the critical appraisal of relevant literature, on the authors' own experience and on discussions that took place at a consensus conference. It aims to review risk factors favoring aspergillosis in ICU patients, with a special emphasis on often overlooked or neglected conditions. In the ICU patients, corticosteroid use to treat underlying conditions such as chronic obstructive pulmonary disease (COPD), sepsis, or severe COVID-19, represents a cardinal risk factor for IA. Important additional host risk factors are COPD, decompensated cirrhosis, liver failure, and severe viral pneumonia (influenza, COVID-19). Clinical observations indicate that patients admitted to the ICU because of sepsis or acute respiratory distress syndrome are more likely to develop probable or proven IA, suggesting that sepsis could also be a possible direct risk factor for IA, as could small molecule inhibitors used in oncology. There are no recommendations for prophylaxis in ICU patients; posaconazole mold-active primary prophylaxis is used in some centers according to guidelines for other patient populations and IA treatment in critically ill patients is basically the same as in other patient populations. A combined evaluation of clinical signs and imaging, classical biomarkers such as the GM assay, and fungal cultures examination, remain the best option to assess response to treatment.

LAY SUMMARY

The use of corticosteroids and the presence of co-morbidities such as chronic obstructive pulmonary disease, acute or chronic advanced liver disease, or severe viral pneumonia caused by influenza or Covid-19, may increase the risk of invasive aspergillosis in intensive care unit patients.

Population Pharmacokinetics and Pharmacodynamic Target Attainment of Isavuconazole against Aspergillus fumigatus and Aspergillus flavus in Adult Patients with Invasive Fungal Diseases: Should Therapeutic Drug Monitoring for Isavuconazole Be Considered as Mandatory as for the Other Mold-Active Azoles?

Isavuconazole is a newer broad-spectrum triazole approved for the treatment of invasive fungal disease. The objective of this study was to conduct a population pharmacokinetic and pharmacodynamic analysis of isavuconazole in a retrospective cohort of hospitalized patients. A nonlinear mixed-effect approach with Monte Carlo simulations was conducted to assess the probability of target attainment (PTA) of an area under the concentration–time curve (AUC_{24 h})/minimum inhibitory concentration (MIC) ratio of 33.4 (defined as efficacy threshold against A. fumigatus and A. flavus) associated with a maintenance dose (MD) of 100, 200 and 300 mg daily after loading. The cumulative fraction of response (CFR) against the EUCAST MIC distributions of A. fumigatus and A. flavus was calculated as well. The proportion of trough concentrations (C_trough) exceeding a defined threshold of toxicity (>5.13 mg/L) was estimated. A total of 50 patients, with a median age of 61.5 years, provided 199 plasma isavuconazole concentrations. Invasive pulmonary aspergillosis was the prevalent type of infection and accounted for 80% (40/50) of cases. No clinical covariates were retained by the model. With the standard MD of 200 mg daily, CFRs were always ≥90% during the first two months of treatment. The risk of C_trough < 1.0 mg/L was around 1%, and that of C_trough > 5.13 mg/L was 27.7 and 39.2% at 28 and 60 days, respectively, due to isavuconazole accumulation over time. Our findings suggest that TDM for isavuconazole should not be considered as mandatory as for the other mold-active azoles voriconazole and posaconazole.

An expanded agar-based screening method for azole-resistant Aspergillus fumigatus

Antifungal susceptibility testing is an essential tool for guiding antifungal therapy. Reference methods are complex and usually only available in specialised laboratories. We have designed an expanded agar-based screening method for the detection of azole-resistant Aspergillus fumigatus isolates. Normally, identification of resistance mechanisms is obtained only after sequencing the cyp51A gene and promoter. However, our screening method provides azole resistance detection and presumptive resistance mechanisms identification. A previous agar-based method consisting of four wells containing voriconazole, itraconazole, posaconazole and a growth control, detected azole resistance to clinical azoles. Here, we have modified the concentrations of voriconazole and posaconazole to adapt to the updated EUCAST breakpoints against A. fumigatus. We have also expanded the method to include environmental azoles to assess azole resistance and the azole resistance mechanism involved. We used a collection of A. fumigatus including 54 azole-resistant isolates with Cyp51A modifications (G54, M220, G448S, TR₅₃ , TR₃₄ /L98H, TR₄₆ /Y121F/T289A, TR₃₄ /L98H/S297T/F495I), and 50 azole susceptible isolates with wild-type Cyp51A. The screening method detects azole-resistant A. fumigatus isolates when there is growth in any of the azole-containing wells after 48h. The growth pattern in the seven azoles tested helps determine the underlying azole resistance mechanism. This approach is designed for surveillance screening of A. fumigatus azole-resistant isolates and can be useful for the clinical management of patients prior to antifungal susceptibility testing confirmation.

Prognostic Scores and Azole-Resistant Aspergillus fumigatus in Invasive Aspergillosis from an Indian Respiratory Medicine ICU (ICU Patients with IA Suspicion)

Objective: To assess the effectiveness of three general prognostic models (APACHE II, SAPS II, and SOFA) with serum galactomannan antigen in a clinically suspected invasive aspergillosis (IA) subpopulation admitted to a respiratory medicine ICU and to identify azole-resistant Aspergillus fumigatus (ARAF) cases. Methodology and Results: A total of 235 clinically suspected IA patients were prospectively enrolled and observed 30-day mortality was 29.7%. The three general models showed poor discrimination assessed by area under receiver operating characteristic (ROC) curves (AUCs, <0.7) and good calibration (p = 0.92, 0.14, and 0.13 for APACHE II, SAPS II, and SOFA, respectively), evaluated using Hosmer–Lemeshow goodness-of-fit tests. However, discrimination was significantly better with galactomannan values (AUC, 0.924). In-vitro antifungal testing revealed higher minimum inhibitory concentration (MIC) for 12/34 isolates (35.3%) whereas azole resistance was noted in 40% of Aspergillus fumigatus isolates (6/15) with two hotspot cyp51A mutations, G54R and P216L. Conclusions: Patients diagnosed with putative and probable IA (71.4% and 34.6%, respectively), had high mortality. The general prognostic model APACHE II seemed fairly accurate for this subpopulation. However, the use of local GM cut-offs calculated for mortality, may help the intensivists in prompt initiation or change of therapy for better outcome of patients. In addition, the high MICs highlight the need of antifungal surveillance to know the local resistance rate which might aid in patient treatment.

Harnessing the Potential of Multiomics Studies for Precision Medicine in Infectious Disease

The field of infectious diseases currently takes a reactive approach and treats infections as they present in patients. Although certain populations are known to be at greater risk of developing infection (eg, immunocompromised), we lack a systems approach to define the true risk of future infection for a patient. Guided by impressive gains in "omics" technologies, future strategies to infectious diseases should take a precision approach to infection through identification of patients at intermediate and high-risk of infection and deploy targeted preventative measures (ie, prophylaxis). The advances of high-throughput immune profiling by multiomics approaches (ie, transcriptomics, epigenomics, metabolomics, proteomics) hold the promise to identify patients at increased risk of infection and enable risk-stratifying approaches to be applied in the clinic. Integration of patient-specific data using machine learning improves the effectiveness of prediction, providing the necessary technologies needed to propel the field of infectious diseases medicine into the era of personalized medicine.

A Human Dectin-2 Deficiency Associated With Invasive Aspergillosis

Immunocompromised patients are highly susceptible to invasive aspergillosis. Herein, we identified a homozygous deletion mutation (507 del C) resulting in a frameshift (N170I) and early stop codon in the fungal binding Dectin-2 receptor, in an immunocompromised patient. The mutated form of Dectin-2 was weakly expressed, did not form clusters at/near the cell surface and was functionally defective. Peripheral blood mononuclear cells from this patient were unable to mount a cytokine (tumor necrosis factor, interleukin 6) response to Aspergillus fumigatus, and this first identified Dectin-2–deficient patient died of complications of invasive aspergillosis.

Risk factors for invasive aspergillosis in ICU patients with COVID-19: current insights and new key elements

Invasive pulmonary aspergillosis (IPA) has always been a challenging diagnosis and risk factors an important guide to investigate specific population, especially in Intensive Care Unit. Traditionally recognized risk factors for IPA have been haematological diseases or condition associated with severe immunosuppression, lately completed by chronic conditions (such as obstructive pulmonary disease, liver cirrhosis, chronic kidney disease and diabetes), influenza infection and Intensive Care Unit (ICU) admission. Recently, a new association with SARS-CoV2 infection, named COVID-19-associated pulmonary aspergillosis (CAPA), has been reported worldwide, even if its basic epidemiological characteristics have not been completely established yet. In this narrative review, we aimed to explore the potential risk factors for the development of CAPA and to evaluate whether previous host factors or therapeutic approaches used in the treatment of COVID-19 critically ill patients (such as mechanical ventilation, intensive care management, corticosteroids, broad-spectrum antibiotics, immunomodulatory agents) may impact this new diagnostic category. Reviewing all English-language articles published from December 2019 to December 2020, we identified 21 papers describing risk factors, concerning host comorbidities, ICU management, and COVID-19 therapies. Although limited by the quality of the available literature, data seem to confirm the role of previous host risk factors, especially respiratory diseases. However, the attention is shifting from patients' related risk factors to factors characterizing the hospital and intensive care course, deeply influenced by specific features of COVID treatment itself. Prolonged invasive or non-invasive respiratory support, as well as the impact of corticosteroids and/or immunobiological therapies seem to play a pivotal role. ICU setting related factors, such as environmental factors, isolation conditions, ventilation systems, building renovation works, and temporal spread with respect to pandemic waves, need to be considered. Large, prospective studies based on new risk factors specific for CAPA are warranted to guide surveillance and decision of when and how to treat this particular population.

Invasive aspergillosis in critically ill patients: Review of definitions and diagnostic approaches

Invasive aspergillosis (IA) is an increasingly recognised phenomenon in critically ill patients in the intensive care unit, including in patients with severe influenza and severe coronavirus disease 2019 (COVID-19) infection. To date, there are no consensus criteria on how to define IA in the ICU population, although several criteria are used, including the AspICU criteria and new consensus criteria to categorise COVID-19-associated pulmonary aspergillosis (CAPA). In this review, we describe the epidemiology of IA in critically ill patients, most common definitions used to define IA in this population, and most common clinical specimens obtained for establishing a mycological diagnosis of IA in the critically ill. We also review the most common diagnostic tests used to diagnose IA in this population, and lastly discuss the most common clinical presentation and imaging findings of IA in the critically ill and discuss areas of further needed investigation.

Putative invasive pulmonary aspergillosis within medical wards and intensive care units: a 4-year retrospective, observational, single-centre study

Blot and colleagues have proposed putative invasive pulmonary aspergillosis (PIPA) definitions for troublesome diagnosis in suspected patients outside the classical criteria of immunosuppression. We retrospectively included in the study all admitted patients with an Aspergillus spp. positive culture within lower airway samples. Overall, Aspergillus spp. positivity in respiratory samples was 0.97 every 1000 hospital admissions (HA): 4.94 and 0.28/1000/HA, respectively, in intensive care units (ICUs) and medical wards (MW). 66.6% fulfilled PIPA criteria, and 33.4% were defined as colonized. 69.2% of PIPA diagnosis occurred in the ICU. Antifungal therapy was appropriate in 88.5% of subjects with PIPA and 37.5% of colonized, confirming the comparison between deads and lives. Patients with PIPA in the ICUs had more frequent COPD, sepsis or septic shock, acute kidney injury (AKI), needed more surgery, mechanical ventilation (MV), vasopressors, hemodialysis, blood or platelets transfusions. PIPA in MW had associated with a history of smoking, interstitial lung disease and inhaled steroid therapy. Overall mortality within 21 days was 50%: 54.2% in ICU, 36,8% in MW. Factors associated with death were length of hospitalization, influenza, pneumonia, liver transplant, AKI, ARDS, sepsis and septic shock. PIPA in the ICU had higher disease severity and needed more organ support than MW cases, despite that cases of PIPA in MW are emerging with trends difficult to demonstrate given the problematic diagnosis.

Genomic Diversity of Azole-Resistant Aspergillus fumigatus in the United States

Azole resistance in pathogenic Aspergillus fumigatus has become a global public health issue threatening the use of medical azoles. The environmentally occurring resistance mutations, TR34/L98H (TR34) and TR46/Y121F/T289A (TR46), are widespread across multiple continents and emerging in the United States. We used whole-genome single nucleotide polymorphism (SNP) analysis on 179 nationally represented clinical and environmental A. fumigatus genomes from the United States along with 18 non-U.S. genomes to evaluate the genetic diversity and foundation of the emergence of azole resistance in the United States. We demonstrated the presence of clades of A. fumigatus isolates: clade A (17%) comprised a global collection of clinical and environmental azole-resistant strains, including all strains with the TR34/L98H allele from India, The Netherlands, the United Kingdom, and the United States, and clade B (83%) consisted of isolates without this marker mainly from the United States. The TR34/L98H polymorphism was shared among azole-resistant A. fumigatus strains from India, The Netherlands, the United Kingdom, and the United States, suggesting the common origin of this resistance mechanism. Six percent of azole-resistant A. fumigatus isolates from the United States with the TR34 resistance marker had a mixture of clade A and clade B alleles, suggestive of recombination. Additionally, the presence of equal proportions of both mating types further suggests the ongoing presence of recombination. This study demonstrates the genetic background for the emergence of azole resistance in the United States, supporting a single introduction and subsequent propagation, possibly through recombination of environmentally driven resistance mutations. IMPORTANCE Aspergillus fumigatus is one of the most common causes of invasive mold infections in patients with immune deficiencies and has also been reported in patients with severe influenza and severe acute respiratory syndrome coronavirus 2 (SARs-CoV-2). Triazole drugs are the first line of therapy for this infection; however, their efficacy has been compromised by the emergence of azole resistance in A. fumigatus, which was proposed to be selected for by exposure to azole fungicides in the environment [P. E. Verweij, E. Snelders, G. H. J. Kema, E. Mellado, et al., Lancet Infect Dis 9:789-795, 2009, https://doi.org/10.1016/S1473-3099(09)70265-8]. Isolates with environmentally driven resistance mutations, TR34/L98H (TR34) and TR46/Y121F/T289A (TR46), have been reported worldwide. Here, we used genomic analysis of a large sample of resistant and susceptible A. fumigatus isolates to demonstrate a single introduction of TR34 in the United States and suggest its ability to spread into the susceptible population is through recombination between resistant and susceptible isolates.

Dual-purpose isocyanides produced by Aspergillus fumigatus contribute to cellular copper sufficiency and exhibit antimicrobial activity

The maintenance of sufficient but nontoxic pools of metal micronutrients is accomplished through diverse homeostasis mechanisms in fungi. Siderophores play a well established role for iron homeostasis; however, no copper-binding analogs have been found in fungi. Here we demonstrate that, in Aspergillus fumigatus, xanthocillin and other isocyanides derived from the xan biosynthetic gene cluster (BGC) bind copper, impact cellular copper content, and have significant metal-dependent antimicrobial properties. xan BGC-derived isocyanides are secreted and bind copper as visualized by a chrome azurol S (CAS) assay, and inductively coupled plasma mass spectrometry analysis of A. fumigatus intracellular copper pools demonstrated a role for xan cluster metabolites in the accumulation of copper. A. fumigatus coculture with a variety of human pathogenic fungi and bacteria established copper-dependent antimicrobial properties of xan BGC metabolites, including inhibition of laccase activity. Remediation of xanthocillin-treated Pseudomonas aeruginosa growth by copper supported the copper-chelating properties of xan BGC isocyanide products. The existence of the xan BGC in several filamentous fungi suggests a heretofore unknown role of eukaryotic natural products in copper homeostasis and mediation of interactions with competing microbes.

A case series of non-valvular cardiac aspergillosis in critically ill solid organ transplant and non-transplant patients and systematic review

INTRODUCTION

Non-valvular cardiac aspergillosis is a rare infection of the pericardium, myocardium or endocardium and is associated with a high mortality. There is a paucity of reports of non-valvular cardiac aspergillosis in critically ill and solid organ transplant (SOT) patients. The majority of cases have been reported in haemato-oncology patients, some of whom have undergone a bone marrow transplant.

OBJECTIVES

We describe four cases affected by non-valvular cardiac aspergillosis in the intensive care setting including a systematic review of this extremely rare infection which is associated with high mortality.

RESULTS

All four-patients died but presented with varying clinical, radiological and microbiological evidence of the disease. Three patients presented following complications after solid organ transplantation, two in the context of acute liver failure and emergency liver transplant and one several years after a double lung transplant. The last patient presented with necrotising gall stone pancreatitis, multi-organ failure and subsequently a prolonged intensive care unit (ICU) stay. On review of the literature, January 1955 to July 2019, 45 cases were identified, with different risk factors, clinical and radiological manifestations, treatment regimen and outcome.

CONCLUSION

Antemortem diagnosis of cardiac aspergillosis is difficult and rare, with no cases reporting positive blood culture results. Galactomannan serology has poor sensitivity in solid organ transplant patients, further reduced by prophylactic antimicrobial treatment, which is common in the ICU setting especially post-transplant patients. Due to the scarcity of cases, treatment is extrapolated from invasive aspergillosis management, with emphasis on early treatment with combination therapy.

Surgical Treatment of Pulmonary Aspergilloma: A 13-year Experience from a Single Clinical Center

BACKGROUND

Pulmonary aspergilloma is chronic and invasive, potentially leading to life-threatening massive hemoptysis. The role of surgery for treating pulmonary aspergilloma and its effect on long-term survival need more study.

METHODS

We reviewed 166 patients with aspergillomas treated at Shanghai Pulmonary Hospital from 2004 to 2017. Surgery indications included destroyed lung parenchyma, recurrent hemoptysis despite appropriate medical treatment and isolated pulmonary nodules suspected to be aspergilloma. Pulmonary aspergillomas are classified as simple (in an isolated thin-walled cavity, ≤3 mm) or complex (a thick-walled cyst, >3 mm) based on CT scan findings.

RESULTS

Aspergilloma was complex in 100 (60.2%) patients and simple in 66 (39.8%) patients. The median size of complex aspergillomas (2.5 [0.3-8.0] cm) was larger than that (2.0 [0.2-6.0] cm) of simple types (p<0.001). Hemoptysis occurred in 72 (72%) patients with complex disease and 35 (53%) with simple disease (p=0.014). Video-assisted thoracoscopic surgeries were performed in 42 (63.6%) simple aspergillomas, while 75 (75%) of complex aspergillomas patients underwent thoracotomy. Prolonged air leakage (>7d) was the most (17, [10.2%]) common postoperative complication. One (0.6%) patient had postoperative bronchopleural fistula. One (0.6%) patient died within 30 days postoperatively due to respiratory failure. Two (1.2%) patients experienced recurrence during follow-up. The overall 10-year survival rates of complex and simple aspergillomas were 87.7% and 94.97% (p=0.478). Diabetes (12, [7.2%], HR [95% CI] = 13.15(1.12-154.46)) was associated with a worse prognosis.

CONCLUSIONS

The perioperative morbidity and mortality of pulmonary aspergillomas are acceptable. Overall survival rates of simple and complex types are comparable.

Invasive aspergillosis is a critical determinant of mortality in cirrhosis: a systematic review with meta-analysis

Invasive fungal infections pose a severe threat in unconventional immunocompromised hosts such as cirrhosis. Herein we review the impact of invasive aspergillosis (IA) on the prognosis of cirrhosis patients. An electronic search for full-text articles describing IA in cirrhosis was conducted and the disease outcomes and mortality (point-estimate and comparative risk) were pooled on random-effects meta-analysis. Of 4127 articles, 11 studies (9 with good/fair and 2 with poor quality) were included. IA was associated with high disease severity and multi-organ failures in cirrhosis. The pooled-mortality of IA was 81.8% (95%CI: 64.3-91.8, I2 = 59%, p<0.01). Estimate's-heterogeneity (I2) was explored through sub-groups, meta-regression, and influential diagnostics. Mortality estimates were higher among subgroups of acute-on-chronic liver failure (ACLF, 86.4%) and intensive care unit (ICU)-admitted patients (84.0%). The odds of mortality related to IA were 8.9 times higher than controls and much higher in ACLF (OR: 22.5) and ICU-admitted patients (OR: 36.4). The odds of mortality in IA were 4.1, 12.9, and 48.6 times higher than bacterial, no-fungal infections, and no-infection controls. There was no asymmetry in mortality-estimates or odds ratios and mortality in IA was high irrespective of country of origin, site of infection, proven or probable category, and quality of study. Thus, IA is associated with very high mortality in cirrhosis patients, especially in ACLF and ICU-admitted patients. Intensive research is needed for the rapid diagnosis and treatment of IA in cirrhosis.

[Individualized antifungal therapy in critically ill patients with invasive fungal infection]

Invasive candidiasis (IC) is the most common invasive fungal infection (IFI) affecting critically ill patients, followed by invasive pulmonary aspergillosis (IPA). International guidelines provide different recommendations for a first-line antifungal therapy and, in most of them, echinocandins are considered the first-line treatment for IC, and triazoles are so for the treatment of IPA. However, liposomal amphotericinB (L-AmB) is still considered a second-line therapy for both clinical entities. Although in the last decade the management of IFI has improved, several controversies persist. The antifungal drugs currently available may have a suboptimal activity, or be wrongly used in certain IFI involving critically ill patients. The aim of this review is to analyze when to provide individualized antifungal therapy to critically ill patients suffering from IFI, emphasizing the role of L-AmB. Drug-drug interactions, the clinical status, infectious foci (peritoneal candidiasis is discussed), the fungal species involved, and the need of monitoring the concentration of the antifungal drug in the patient are considered.

A Large Retrospective Assessment of Voriconazole Exposure in Patients Treated with Extracorporeal Membrane Oxygenation

BACKGROUND

Voriconazole is one of the first-line therapies for invasive pulmonary aspergillosis. Drug concentrations might be significantly influenced by the use of extracorporeal membrane oxygenation (ECMO). We aimed to assess the effect of ECMO on voriconazole exposure in a large patient population.

METHODS

Critically ill patients from eight centers in four countries treated with voriconazole during ECMO support were included in this retrospective study. Voriconazole concentrations were collected in a period on ECMO and before/after ECMO treatment. Multivariate analyses were performed to evaluate the effect of ECMO on voriconazole exposure and to assess the impact of possible saturation of the circuit's binding sites over time.

RESULTS

Sixty-nine patients and 337 samples (190 during and 147 before/after ECMO) were analyzed. Subtherapeutic concentrations (<2 mg/L) were observed in 56% of the samples during ECMO and 39% without ECMO (p = 0.80). The median trough concentration, for a similar daily dose, was 2.4 (1.2-4.7) mg/L under ECMO and 2.5 (1.4-3.9) mg/L without ECMO (p = 0.58). Extensive inter-and intrasubject variability were observed. Neither ECMO nor squared day of ECMO (saturation) were retained as significant covariates on voriconazole exposure.

CONCLUSIONS

No significant ECMO-effect was observed on voriconazole exposure. A large proportion of patients had voriconazole subtherapeutic concentrations.

COVID-19 and invasive fungal coinfections: A case series at a Brazilian referral hospital

Background

COVID-19 co-infections have been described with different pathogens, including filamentous and yeast fungi.

Methodology

A retrospective case series study conducted from February to December 2020, at a Brazilian university hospital. Data were collected from two hospital surveillance systems: Invasive fungal infection (IFI) surveillance (Mycosis Resistance Program - MIRE) and COVID-19 surveillance. Data from both surveillance systems were cross-checked to identify individuals diagnosed with SARS-CoV-2 (by positive polymerase chain reaction (PCR)) and IFI during hospital stays within the study period.

Results

During the study period, 716 inpatients with COVID-19 and 55 cases of IFI were identified. Fungal co-infection with SARS-CoV-2 was observed in eight (1%) patients: three cases of aspergillosis; four candidemia and one cryptococcosis. The median age of patients was 66 years (IQR 58-71 years; range of 28-77 years) and 62.5% were men. Diagnosis of IFI occurred a median of 11.5 days (IQR 4.5-23 days) after admission and 11 days (IQR 6.5-16 days) after a positive PCR result for SARS-CoV-2. In 75% of cases, IFI was diagnosed in the intensive care unit (ICU). Cases of aspergillosis emerged earlier than those of candidemia: an average of 8.6 and 28.6 days after a positive PCR for SARS-CoV-2, respectively. All the patients with both infections ultimately died.

Conclusion

A low rate of COVID-19 co-infection with IFI was observed, with high mortality. Most cases were diagnosed in ICU patients. Aspergillosis diagnosis is highly complex in this context and requires different criteria.

Deciphering Aspergillus fumigatus cyp51A-mediated triazole resistance by pyrosequencing of respiratory specimens

Background

Infections caused by triazole drug-resistant Aspergillus fumigatus are an increasing problem. The sensitivity of standard culture is poor, abrogating susceptibility testing. Early detection of resistance can improve patient outcomes, yet tools for this purpose are limited.

Objectives

To develop and validate a pyrosequencing technique to detect resistance-conferring cyp51A polymorphisms from clinical respiratory specimens and A. fumigatus isolates.

Methods

Method validation was performed by Sanger sequencing and pyrosequencing of 50 A. fumigatus isolates with a spectrum of triazole susceptibility patterns. Then, 326 Aspergillus quantitative PCR (qPCR)-positive respiratory samples collected over a 27 month period (January 2017–March 2019) from 160 patients at the UK National Aspergillosis Centre were assessed by cyp51A pyrosequencing. The Sanger sequencing and pyrosequencing results were compared with those from high-volume culture and standard susceptibility testing.

Results

The cyp51A genotypes of the 50 isolates analysed by pyrosequencing and Sanger sequencing matched. Of the 326 Aspergillus qPCR-positive respiratory specimens, 71.2% were reported with no A. fumigatus growth. Of these, 56.9% (132/232) demonstrated a WT cyp51A genotype and 31.5% (73/232) a resistant genotype by pyrosequencing. Pyrosequencing identified the environmental TR34/L98H mutation in 18.7% (61/326) of the samples in contrast to 6.4% (21/326) pan-azole resistance detected by culture. Importantly, pyrosequencing detected resistance earlier than culture in 23.3% of specimens.

Conclusions

The pyrosequencing assay described could detect a wide range of cyp51A polymorphisms associated with triazole resistance, including those not identified by commercial assays. This method allowed prompt recognition of resistance and the selection of appropriate antifungal treatment when culture was negative.

Blockade Of PD-1 Attenuated Postsepsis Aspergillosis Via The Activation of IFN-γ and The Dampening of IL-10

BACKGROUND

Nosocomial aspergillosis in patients with sepsis has emerged in the past few years. Blockade of PD-1/PD-L pathway has tended to become a promising therapeutic strategy as it improved the outcome of bacterial sepsis and postsepsis secondary fungal infection. Recently, the controversial effects of PD-1 blockade on infectious diseases, including aspergillosis, have been demonstrated; therefore, the efficacy of anti-PD-1 drug still remains to be elucidated.

METHODS

Cecal ligation and puncture (CLP) was conducted as a mouse sepsis model. Aspergillus fumigatus spores were intravenously inoculated on day 5 post-CLP, when the immune cells succumbed to exhaustion. Amphotericin B was medicated together with or without anti-PD-1 treatment after Aspergillus infection.

RESULTS

Amphotericin B alone was not effective to treat the CLP-mice with secondary aspergillosis. In contrast, antifungal medication with the adjunctive anti-PD-1 treatment attenuated the fungal burdens in blood and internal organs, and improved the survival rate of the mice with secondary aspergillosis. These outcomes of PD-1 blockade were concurring with the enhanced CD86 expression on splenocytes, the augmented serum IFN-γ, and the dampened IL-10. Activated T cells from anti-PD-1-treated mice also highly increased IFN-γ and diminished IL-10 production.

CONCLUSION

The blockade of PD-1 on postsepsis aspergillosis presumably reinvigorated exhausted antigen-presenting cells and T cells by upregulating CD86 expression and IFN-γ production, and dampened IL-10 production, which consequently leaded to the attenuation of secondary aspergillosis. The adjunctive anti-PD-1 therapy may become a promising strategy for the advanced immunotherapy against lethal fungal infection.

Aspergillus fumigatus Influences Gasdermin-D-Dependent Pyroptosis of the Lung via Regulating Toll-Like Receptor 2-Mediated Regulatory T Cell Differentiation

Purpose

Aspergillus fumigatus, as an opportunistic fungus, has developed a series of escape mechanisms under the host's immune response to obtain nutrients and promote fungal growth in the hostile environment. The immune escape of pathogens may be through suppressing the inflammatory response mediated by regulatory T cells (Tregs). The aim of this study was to explore whether A. fumigatus influences Gasdermin-D-dependent pyroptosis of the lung by regulating Toll-like receptor 2-mediated regulatory T cell differentiation.

Methods

Collect peripheral blood from patients with A. fumigatus. ELISA kits we used to detect the expression levels of IL-1β, IL-6, IL-2R, and IL-10 in the serum and flow cytometry to detect the percentage of CD4⁺CD25⁺Foxp3⁺ Tregs in the patients' peripheral blood mononuclear cells (PBMCs). The mouse model of A. fumigatus infection was constructed by tracheal instillation. The pathological changes in the lungs of the mice were observed under a microscope. The fungal load in the lung tissue was determined by the plate colony count. ELISA kit was used to detect the lung tissue homogenate proinflammatory cytokines TNF-α, IL-6, CCL2, and VEGF. Q-PCR was used for the detection of the expression of Foxp3 and TLR2 genes in the lung. Western blot was used for the detection of the expression of TLR2, Gasdermin-D (GSDMD), IL-1α, and IL-1β in the lung. Flow cytometry was used to detect splenic CD4⁺CD25⁺FOXP3⁺ Tregs. Using magnetic beads to extract CD4⁺ T cells from mice spleen, the effects of A. fumigatus conidia or TLR2 inhibitor (C29) to differentiate CD4⁺ T cells in vitro were tested.

Results

The expression of Foxp3 and TLR2 in the lung tissue of mice infected with A. fumigatus increased, and we observed that the proportion of Tregs in both A. fumigatus infection patients and mice was upregulated. After using the CD25 neutralizing antibody, the number of Tregs in the mice spleen was significantly reduced. However, lung damage was reduced and the ability to clear lung fungi was enhanced. We found that the Tregs in TLR2^−/− mice were significantly reduced and the nonlethal dose of A. fumigatus conidia did not cause severe lung damage in TLR2^−/− mice. Compared with that of wild-type mice, the fungal burden in the lung of TLR2-deficient mice was reduced and the knockout of TLR2 changed the expression of GSDMD, IL-1α, and IL-1β in A. fumigatus. In in vitro experiments, we found that the inhibition of TLR2 can reduce Treg differentiation.

Conclusions

A. fumigatus triggers CD4⁺CD25⁺FOXP3⁺ Treg proliferation and differentiation by activating the TLR2 pathway, which may be a potential mechanism for evading host defenses in A. fumigatus. This effect can modulate GSDMD-dependent pyroptosis and may partly involve TRL2 signaling.

Patient notification about suspected hospital-associated outbreaks of invasive mold infections: Considerations for public health and hospital personnel

A common type of fungal disease investigation involves hospital-associated clusters of invasive mold infections (IMIs), which typically occur among immunocompromised patients. Responding to IMI clusters can be challenging for public health and hospital personnel for several reasons such as difficulty of confirming the existence of an outbreak, difficulty of determining source. Although many resources exist to guide patient notification about healthcare incidents (eg, bloodborne exposures, disease outbreaks), IMI clusters involve special considerations related to the complex diseases, uncertain exposures, and differential benefits and risks of notification. Early, nuanced communication about hospital-associated IMI clusters is almost always the best course of action to help reduce risks to patients' health and foster trust between patients and hospitals.

Microbial Air Quality in Healthcare Facilities

There is increasing evidence that indoor air quality and contaminated surfaces provide an important potential source for transmission of pathogens in hospitals. Airborne hospital microorganisms are apparently harmless to healthy people. Nevertheless, healthcare settings are characterized by different environmental critical conditions and high infective risk, mainly due to the compromised immunologic conditions of the patients that make them more vulnerable to infections. Thus, spread, survival and persistence of microbial communities are important factors in hospital environments affecting health of inpatients as well as of medical and nursing staff. In this paper, airborne and aerosolized microorganisms and their presence in hospital environments are taken into consideration, and the factors that collectively contribute to defining the infection risk in these facilities are illustrated.

Risk factors of non-invasive ventilation failure in hematopoietic stem-cell transplantation patients with acute respiratory distress syndrome

Background:

Non-invasive ventilation (NIV) was one of the first-line ventilation supports for hematopoietic stem-cell transplantation (HSCT) patients with acute respiratory distress syndrome (ARDS). Successful NIV may avoid need for intubation. However, the influence NIV failure had on patients’ outcome and its risk factors were hardly known.

Methods:

In this retrospective observational study, we reported risk factors and incidence of NIV failure in HSCT patients who were admitted to the Intensive Care Unit (ICU) with a diagnosis of ARDS and supported with mechanical ventilation, in a 5-year period. Patient outcomes, such as ventilator-free days, ICU-free days, and ICU mortality were also reported.

Results:

Of all the 94 patients included, 70 patients were initially supported with NIV. NIV failure occurred in 44 (63%) patients. Male sex, elevated serum galactomannan (GM) test, (1-3)-β-D-glucan (BG) assay, or elevated serum creatinine level were risk factors for NIV failure. When compared with the NIV success group, failure of NIV was associated with much fewer ICU-free days (22 versus 0, p < 0.001, Cohen’s d = 0.62) and higher ICU mortality (9.5% versus 75.5%, p < 0.001, Pearson’s r = 0.75). There was no difference in ICU-free days, ventilator-free days and ICU mortality between NIV failure and initial invasive mechanical ventilation (IMV) groups. Patients who failed in NIV support had a higher ICU mortality (75.5%) than those who succeeded (9.5%).

Conclusion:

In a small cohort of HSCT patients with mainly moderate severity of ARDS, male patients with elevated serum GM/BG test or serum creatinine level had a higher risk of NIV failure. Both NIV failure and initial IMV groups were characterized by high mortality rate and extremely low ICU-free days and ventilator-free days; failure of NIV support may further aggravate patient prognosis.

The reviews of this paper are available via the supplemental material section.

Influenza- and COVID-19-Associated Pulmonary Aspergillosis: Are the Pictures Different?

Invasive pulmonary aspergillosis (IPA) in intensive care unit patients is a major concern. Influenza-associated acute respiratory distress syndrome (ARDS) and severe COVID-19 patients are both at risk of developing invasive fungal diseases. We used the new international definitions of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA) to compare the demographic, clinical, biological, and radiological aspects of IAPA and CAPA in a monocentric retrospective study. A total of 120 patients were included, 71 with influenza and 49 with COVID-19-associated ARDS. Among them, 27 fulfilled the newly published criteria of IPA: 17/71 IAPA (23.9%) and 10/49 CAPA (20.4%). Kaplan–Meier curves showed significantly higher 90-day mortality for IPA patients overall (p = 0.032), whereas mortality did not differ between CAPA and IAPA patients. Radiological findings showed differences between IAPA and CAPA, with a higher proportion of features suggestive of IPA during IAPA. Lastly, a wide proportion of IPA patients had low plasma voriconazole concentrations with a higher delay to reach concentrations > 2 mg/L in CAPA vs. IAPA patients (p = 0.045). Severe COVID-19 and influenza patients appeared very similar in terms of prevalence of IPA and outcome. The dramatic consequences on the patients’ prognosis emphasize the need for a better awareness in these particular populations.

An overview of current and emerging antifungal pharmacotherapy for invasive fungal infections

Introduction: Invasive fungal infections (IFIs) remain a significant cause of morbidity and mortality despite significant advancements in currently available therapy. With a flush pipeline of investigational antifungals, the clinician must identify appropriate roles of currently available therapies, potential advantages of emerging antifungals, and shortcomings in the evolving clinical evidence.Areas covered: Standard and developing treatment approaches for IFIs with currently available antifungals are summarized with a focus on invasive candidiasis and invasive aspergillosis. Emerging investigational antifungals are discussed in depth, including mechanisms of action, fungal activity, clinical evidence, and ongoing research. An opinion on the impact and potential role of therapy for emerging antifungals of interest is also provided.Expert opinion: Despite advances and clinical studies optimizing antifungal use, current therapies fall short in preventing IFI morbidity and mortality. Further optimization of currently available antifungals may improve outcomes; however, novel agents are required for historically difficult-to-treat infections, transitions to oral treatment, minimizing adverse drug effects, decreasing drug interactions, and ultimately improving patient quality of life. Emerging antifungals may positively revolutionize the treatment of IFIs.

Effects of antifungal agents on the fungal proteome: informing on mechanisms of sensitivity and resistance

INTRODUCTION

Antifungal agents are essential in the fight against serious fungal disease, however emerging resistance is threatening an already limited collection of therapeutics. Proteomic analyses of effects of antifungal agents can expand our understanding of multifactorial mechanisms of action and have also proven valuable to elucidate proteomic changes associated with antifungal resistance.

AREAS COVERED

This review covers the application of proteomic techniques to examine sensitivity and resistance to antifungals including commonly used therapeutics, amphotericin B, echinocandins and the azoles, based predominantly on studies involving Aspergillus fumigatus, Candida albicans and Candida glabrata from the last 10 years. In addition, non-clinical antimicrobial agents are also discussed, which highlight the potential of proteomics to identify new antifungal targets.

EXPERT COMMENTARY

Fungal proteomics has evolved in the last decade with increased genome availability and developments in mass spectrometry. Collectively, these have led to the advancement of proteomic techniques, allowing increased coverage of the proteome. Gel-based proteomics laid the foundation for these types of studies, which has now shifted to the more powerful gel-free proteomics. This has resulted in the identification of key mediators and potential biomarkers of antifungal resistance, as well as elucidating the mechanisms of action of novel and established antifungal agents.

Performance of Existing Definitions and Tests for the Diagnosis of Invasive Fungal Diseases other than Invasive Candidiasis and Invasive Aspergillosis in Critically Ill, Adult Patients: A Systematic Review with Qualitative Evidence Synthesis

The Fungal Infections Definitions in Intensive Care Unit (ICU) patients (FUNDICU) project aims to provide standard sets of definitions for invasive fungal diseases (IFDs) in critically ill, adult patients, including invasive aspergillosis (IA), invasive candidiasis (IC), Pneumocystis jirovecii pneumonia (PJP), and other non-IA, non-IC IFDs. The first step of the project was the conduction of separated systematic reviews of the characteristics and applicability to critically ill, adult patients outside classical populations at risk (hematology patients, solid organ transplant recipients) of available definitions and diagnostic tests for IFDs. We report here the results of two systematic reviews exploring the performance of available definitions and tests, for PJP and for other non-IA, non-IC IFDs. Starting from 2585 and 4584 records for PJP and other IFDs, respectively, 89 and 61 studies were deemed as eligible for full-text evaluation. However, only two studies for PJP and no studies for other IFDs met the FUNDICU protocol criteria for inclusion in qualitative synthesis. Currently, there is no sufficient solid data for directly evaluating the performance of existing definitions and laboratory tests for the diagnosis of PJP and other non-IA, non-IC IFDs in critically ill adult patients outside classical populations at risk.

Fatal disseminated aspergillosis in an immunocompetent patient with COVID-19 due to Aspergillus ochraceus

Aspergillus infection is a well-known complication of severe influenza and severe acute respiratory syndrome coronavirus (SARS-CoV), and these infections have been related with significant morbidity and mortality even when appropriately diagnosed and treated. Recent studies have indicated that SARS-CoV-2 might increase the risk of invasive pulmonary aspergillosis (IPA). Here, we report the first case of Aspergillus ochraceus in a SARS-CoV-2 positive immunocompetent patient, which is complicated by pulmonary and brain infections. Proven IPA is supported by the positive Galactomannan test, culture-positive, and histopathological evidence. The patient did not respond to voriconazole, and liposomal amphotericin B was added to his anti-fungal regimen. Further studies are needed to evaluate the prevalence of IPA in immunocompetent patients infected with SARS-CoV-2. Consequently, testing for the incidence of Aspergillus species in lower respiratory secretions and Galactomannan test of COVID-19 patients with appropriate therapy and targeted anti-fungal therapy based on the primary clinical suspicion of IPA are highly recommended.

Frequency of Positive Aspergillus Tests in COVID-19 Patients in Comparison to Other Patients with Pulmonary Infections Admitted to the Intensive Care Unit

The aim of this study was to describe the frequency of positive Aspergillus tests in COVID-19 patients and investigate the association between COVID-19 and a positive Aspergillus test result. We compared the proportion of positive Aspergillus tests in COVID-19 patients admitted to the intensive care unit (ICU) for >24 h with two control groups: patients with community-acquired pneumonia with (i) a PCR-confirmed influenza infection (considered a positive control since the link between influenza and invasive aspergillosis has been established) and (ii) Streptococcus pneumoniae pneumonia (in whom positive Aspergillus tests are mostly considered to indicate colonization).

The aim of this study was to describe the frequency of positive Aspergillus tests in COVID-19 patients and investigate the association between COVID-19 and a positive Aspergillus test result. We compared the proportion of positive Aspergillus tests in COVID-19 patients admitted to the intensive care unit (ICU) for >24 h with two control groups: patients with community-acquired pneumonia with (i) a PCR-confirmed influenza infection (considered a positive control since the link between influenza and invasive aspergillosis has been established) and (ii) Streptococcus pneumoniae pneumonia (in whom positive Aspergillus tests are mostly considered as colonization). During the study period, 92 COVID-19 patients (mean [standard deviation] age, 62 [14] years; 76.1% males), 48 influenza patients (55 [14]; 56.2% males), and 65 pneumococcal pneumonia patients (58 [15], 63,1% males) were identified. Any positive Aspergillus test from any respiratory sample was found in 10.9% of the COVID-19 patients, 6.2% of the patients with pneumococcal pneumonia, and 22.9% of those infected with influenza. A positive culture or PCR or galactomannan test on bronchoalveolar lavage (BAL) fluid only was found in 5.4% of COVID-19 patients, which was lower than in patients with influenza (18.8%) and comparable to that in the pneumococcal pneumonia group (4.6%). Using logistic regression analysis, the odds ratio (OR) (95% confidence interval) for a positive Aspergillus test on BAL fluid for COVID-19 patients was 1.2 (0.3 to 5.1; P = 0.8) compared to the pneumococcal pneumonia group, while it was 0.2 (0.1 to 0.8; P = 0.02) compared to the influenza group. This difference remained significant when corrected for age and sex. In conclusion, in COVID-19 patients, the prevalence of a positive Aspergillus test was comparable to that in patients admitted for pneumococcal pneumonia but substantially lower than what we observed in patients with influenza.

Clinical experience with isavuconazole in healthy volunteers and patients with invasive aspergillosis in China, and the results from an exposure-response analysis

BACKGROUND

Isavuconazole is a broad-spectrum triazole for the treatment of invasive fungal disease (IFD).

OBJECTIVE

To investigate the clinical experience with isavuconazole in Chinese individuals.

PATIENTS/METHODS

Participants were Chinese healthy volunteers from a Phase I pharmacokinetics (PK) and safety study of single/multiple doses of isavuconazole (n = 36) and Chinese patients from the global Phase III SECURE study that assessed safety and efficacy of isavuconazole vs voriconazole for IFD treatment (n = 26).

RESULTS

No clinically relevant differences in PK were found between Chinese and Western participants, although exposure was increased in Chinese volunteers. Treatment-emergent adverse events (TEAEs) were reported in 75.0% of healthy volunteers, many of which were infusion-related. No serious AEs were reported. In SECURE, findings in Chinese patients (n = 26) were similar to the global population. For patients who received ≥1 dose of study drug, allcause mortality from first dose to Day 42 was 10.0% (1/10) with isavuconazole and 25.0% (4/16) with voriconazole (treatment difference [95% confidence interval, CI]: -15.0% [-43.2%, 13.2%]). Overall response at the end of treatment for patients with proven/probable IFD was 25.0% and 16.7% with isavuconazole and voriconazole, respectively (treatment difference [95% CI] -8.3% [-60.2%, 43.5%]). Isavuconazole was associated with lower incidence of hepatobiliary, eye, skin, subcutaneous tissue and psychiatric disorders compared with voriconazole and lower incidence of treatment-related TEAEs, serious TEAES or death overall.

CONCLUSIONS

Although further research is required, this study demonstrated a favourable risk-benefit profile of isavuconazole in Chinese patients.

Th17 cells are involved in mouse chronic obstructive pulmonary disease complicated with invasive pulmonary aspergillosis

BACKGROUND

The incidence of chronic obstructive pulmonary disease (COPD) complicated with invasive pulmonary aspergillosis (IPA) has increased in the last two decades. The mechanism underpinning susceptibility to and high mortality of COPD complicated with IPA is unclear, and the role of T helper cells 17 (Th17 cells) in the compound disease remains unknown. Therefore, this study aimed to assess the function of Th17 cells in COPD combined with IPA.

METHODS

COPD, IPA, and COPD+IPA mouse models were established in male wild type C57/BL6 mice. The amounts of Th17 cells and retinoic acid-related orphan receptors γt (RORγt) were tested by flow cytometry. Then, serum interleukin (IL)-17 and IL-23 levels were detected by enzyme-linked immunosorbent assay (ELISA) in the control, COPD, IPA and COPD+IPA groups. In addition, COPD+IPA was induced in IL-17 knockout (KO) mice, for determining the role of Th17 cells in COPD+IPA.

RESULTS

Compared with the COPD group, the COPD+IPA group showed higher amounts of blood RORγt ([35.09 ± 16.12]% vs. [17.92 ± 4.91]%, P = 0.02) and serum IL-17 (17.96 ± 9.59 pg/mL vs. 8.05 ± 4.44 pg/mL, P = 0.02), but blood ([5.18 ± 1.09]% vs. [4.15 ± 0.87]%, P = 0.28) and lung levels of Th17 cells ([1.98 ± 0.83]% vs. [2.03 ± 0.98]%, P = 0.91), lung levels of RORγt ([9.58 ± 6.93]% vs. [9.63 ± 5.98]%, P = 0.49) and serum IL-23 (51.55 ± 27.82 pg/mL vs. 68.70 ± 15.20 pg/mL, P = 0.15) showed no significant differences. Compared with the IPA group, the COPD+IPA group displayed lower amounts of blood ([5.18 ± 1.09]% vs. [9.21 ± 3.56]%, P = 0.01) and lung Th17 cells ([1.98 ± 0.83]% vs. [6.29 ± 1.11]%, P = 0.01) and serum IL-23 (51.55 ± 27.82 pg/mL vs. 154.90 ± 64.60 pg/mL, P = 0.01) and IL-17 (17.96 ± 9.59 pg/mL vs. 39.81 ± 22.37 pg/mL, P = 0.02), while comparable blood ([35.09 ± 16.12]% vs. [29.86 ± 15.42]%, P = 0.25) and lung levels of RORγt ([9.58 ± 6.93]% vs. [15.10 ± 2.95]%, P = 0.18) were found in these two groups. Finally, Aspergillus load in IL-17 KO COPD+IPA mice was almost 2 times that of COPD+IPA mice (1,851,687.69 ± 944,480.43 vs. 892,958.10 ± 686,808.80, t = 2.32, P = 0.02).

CONCLUSION

These findings indicate that Th17 cells might be involved in the pathogenesis of COPD combined with IPA, with IL-17 likely playing an antifungal role.

Factors Contributing to Sex Differences in Mice Inhaling Aspergillus fumigatus

Aspergillus fumigatus is a respiratory fungal pathogen and an allergen, commonly detected in flooded indoor environments and agricultural settings. Previous studies in Balb/c mice showed that repeated inhalation of live and dry A. fumigatus spores, without any adjuvant, elevated allergic immune response and airway remodeling. Sex-specific differences can influence host-pathogen interactions and allergic-asthma related outcomes. However, the effect of host sex on immune response, in the context of A. fumigatus exposure, remains unknown. In this study, we quantified the multivariate and univariate immune response of C57BL/6J mice to live, dry airborne A. fumigatus spores. Our results corroborate previous results in Balb/c mice that repeated inhalation of live A. fumigatus spores is sufficient to induce mucus production and inflammation by day 3 post last challenge, and antibody titers and collagen production by day 28 post-challenge. Principal Component Analysis (PCA) showed that females exhibited significantly higher levels of immune components than males did. Taken together, our data indicate that host-sex is an important factor in shaping the immune response against A. fumigatus, and must be considered when modeling disease in animals, in designing diagnostics and therapeutics for A. fumigatus-associated diseases or while drafting evidence-based guidelines for safe mold levels.

Distribution of invasive fungal infections: Molecular epidemiology, etiology, clinical conditions, diagnosis and risk factors: A 3-year experience with 490 patients under intensive care

Recently, the prevalence of invasive fungal infections (IFIs) is rising. The global mortality rate of IFIs is 10-49%. This study aimed to determine the prevalence, the causative agents, and the risk factors associated with the invasive fungal infections in a tertiary health center to provide valid decision-grounds for healthcare professionals to effectively prevent, control, and treat fungal infections. The current study was conducted on 1477 patients suspected to have systemic fungal infections from different units of the hospital. After screening using routine mycological examination, the patients were confirmed with complementary mycological and molecular methods. Patients were included based on the confirmed diagnosis of IFI and excluded based on lack of a microbiologically and histologically proven diagnosis of IFI. Of the 1477 patients recruited in this study, confirmed cases of fungal infection were 490 (169 proven; 321 cases probable). Among the fungi recovered, Candida species had the highest frequency 337 (68.8%) followed by Aspergillus species 108 (22.1%), Zygomycetes species 21 (4.3%), non-Candida yeast 9 (1.8%). Others were black fungi 5 (1%), mycetoma agents 5 (1%), Fusarium 4 (0.8%), and Trichoderma (0.2%). Hematologic malignancies and diabetes mellitus were the most common underlying diseases among IFI-confirmed patients. This study observed an increased frequency of invasive candidiasis with non-albicans Candida and other invasive saprophytic fungal infections. The increased rate of invasive candidiasis with non-albicans agents highlights a new perspective in the epidemiology and treatment of invasive fungal infections.

Point of care aspergillus testing in intensive care patients

Background

Invasive pulmonary aspergillosis (IPA) is an increasingly recognized complication in intensive care unit (ICU) patients, especially those with influenza, cirrhosis, chronic obstructive pulmonary disease, and other diseases. The diagnosis can be challenging, especially in the ICU, where clinical symptoms as well as imaging are mostly nonspecific. Recently, Aspergillus lateral flow tests were developed to decrease the time to diagnosis of IPA. Several studies have shown promising results in bronchoalveolar lavage fluid (BALf) from hematology patients. We therefore evaluated a new lateral flow test for IPA in ICU patients.

Methods

Using left-over BALf from adult ICU patients in two university hospitals, we studied the performance of the Aspergillus galactomannan lateral flow assay (LFA) by IMMY (Norman, OK, USA). Patients were classified according to the 2008 EORTC-MSG definitions, the AspICU criteria, and the modified AspICU criteria, which incorporate galactomannan results. These internationally recognized consensus definitions for the diagnosis of IPA incorporate patient characteristics, microbiology and radiology. The LFA was read out visually and with a digital reader by researchers blinded to the final clinical diagnosis and IPA classification.

Results

We included 178 patients, of which 55 were classified as cases (6 cases of proven and 26 cases of probable IPA according to the EORTC-MSG definitions, and an additional 23 cases according to the modified AspICU criteria). Depending on the definitions used, the sensitivity of the LFA was 0.88–0.94, the specificity was 0.81, and the area under the ROC curve 0.90–0.94, indicating good overall test performance.

Conclusions

In ICU patients, the LFA performed well on BALf and can be used as a rapid screening test while waiting for other microbiological results.