Navigating the uncertainties of COVID-19 associated aspergillosis (CAPA): A comparison with influenza associated aspergillosis (IAPA)

Cumulative steroid dose in hospitalized patients and COVID-19-associated pulmonary aspergillosis

BACKGROUND

Severe COVID-19 elicits a hyperimmune response frequently amenable to steroids, which in turn increase the risk for opportunistic infections. COVID-19 associated pulmonary aspergillosis (CAPA) is a complication known to be associated with immunomodulatory treatment. The role of cumulative steroid dose in the development of CAPA is unclear. This study evaluates the relationship between cumulative steroid dose in hospitalized individuals with COVID-19 pneumonia and the risk for CAPA.

METHODS

This retrospective cohort study includes 135 hospitalized patients with PCR-confirmed COVID-19 pneumonia at a tertiary centre in north Mexico. Patients who developed CAPA were matched by age and gender to two controls with COVID-19 pneumonia who did not develop CAPA defined and classified as possible, probable, or proven according to 2020 ECMM/ISHAM criteria. Cumulative steroid dose in dexamethasone equivalents was obtained from admission until death, discharge, or diagnosis of CAPA (whichever occurred first). The risk of CAPA by the continuous cumulative steroid dose was assessed using a logistic regression model.

RESULTS

Forty-five patients were diagnosed with CAPA and matched to 90 controls. Mean age was 61 ± 14 years, and 72% were male. Mean cumulative steroid dose was 66 ± 75 mg in patients without CAPA vs 195 ± 226 mg in patients with CAPA (P<0.001). The risk for CAPA increased with higher cumulative dose of steroids (OR 1.0075, 95% CI: 1.0033-1.0116).

CONCLUSIONS

Patients who developed CAPA had a history of higher cumulative steroid dose during hospitalization. The risk for CAPA increases ∼8% for every 10 mg of dexamethasone used.

Antifungal prophylaxis and pre-emptive therapy: When and how?

The growing pool of critically ill or immunocompromised patients leads to a constant increase of life-threatening invasive infections by fungi such as Aspergillus spp., Candida spp. and Pneumocystis jirovecii. In response to this, prophylactic and pre-emptive antifungal treatment strategies have been developed and implemented for high-risk patient populations. The benefit by risk reduction needs to be carefully weighed against potential harm caused by prolonged exposure against antifungal agents. This includes adverse effects and development of resistance as well as costs for the healthcare system. In this review, we summarise evidence and discuss advantages and downsides of antifungal prophylaxis and pre-emptive treatment in the setting of malignancies such as acute leukaemia, haematopoietic stem cell transplantation, CAR-T cell therapy, and solid organ transplant. We also address preventive strategies in patients after abdominal surgery and with viral pneumonia as well as individuals with inherited immunodeficiencies. Notable progress has been made in haematology research, where strong recommendations regarding antifungal prophylaxis and pre-emptive treatment are backed by data from randomized controlled trials, whereas other critical areas still lack high-quality evidence. In these areas, paucity of definitive data translates into centre-specific strategies that are based on interpretation of available data, local expertise, and epidemiology. The development of novel immunomodulating anticancer drugs, high-end intensive care treatment and the development of new antifungals with new modes of action, adverse effects and routes of administration will have implications on future prophylactic and pre-emptive approaches.

Invasive Pulmonary Aspergillosis in Coronavirus Disease 2019 Patients Lights and Shadows in the Current Landscape

Invasive pulmonary aspergillosis (IPA) presents a known risk to critically ill patients with SARS-CoV-2; quantifying the global burden of IPA in SARS-CoV-2 is extremely challenging. The true incidence of COVID-19-associated pulmonary aspergillosis (CAPA) and the impact on mortality is difficult to define because of indiscriminate clinical signs, low culture sensitivity and specificity and variability in clinical practice between centers. While positive cultures of upper airway samples are considered indicative for the diagnosis of probable CAPA, conventional microscopic examination and qualitative culture of respiratory tract samples have quite low sensitivity and specificity. Thus, the diagnosis should be confirmed with serum and BAL GM test or positive BAL culture to mitigate the risk of overdiagnosis and over-treatment. Bronchoscopy has a limited role in these patients and should only be considered when diagnosis confirmation would significantly change clinical management. Varying diagnostic performance, availability, and time-to-results turnaround time are important limitations of currently approved biomarkers and molecular assays for the diagnosis of IA. The use of CT scans for diagnostic purposes is controversial due to practical concerns and the complex character of lesions presented in SARS-CoV-2 patients. The key objective of management is to improve survival by avoiding misdiagnosis and by initiating early, targeted antifungal treatment. The main factors that should be considered upon selection of treatment options include the severity of the infection, concomitant renal or hepatic injury, possible drug interactions, requirement for therapeutic drug monitoring, and cost of therapy. The optimal duration of antifungal therapy for CAPA is still under debate.

Development of a Corticosteroid-Immunosuppressed Mouse Model to Study the Pathogenesis and Therapy of Influenza-Associated Pulmonary Aspergillosis

Influenza-associated pulmonary aspergillosis (IAPA) is a feared complication in patients with influenza tracheobronchitis, especially those receiving corticosteroids. Herein, we established a novel IAPA mouse model with low-inoculum Aspergillus infection and compared outcomes in mice with and without cortisone acetate (CA) immunosuppression. CA was an independent predictor of increased morbidity/mortality in mice with IAPA. Early antifungal treatment with liposomal amphotericin B was pivotal to improve IAPA outcomes in CA-immunosuppressed mice, even after prior antiviral therapy with oseltamivir. In summary, our model recapitulates key clinical features of IAPA and provides a robust preclinical platform to study the pathogenesis and treatment of IAPA.

Immunity to fungi in the lung

The respiratory tree maintains sterilizing immunity against human fungal pathogens. Humans inhale ubiquitous filamentous molds and geographically restricted dimorphic fungal pathogens that form small airborne conidia. In addition, pathogenic yeasts, exemplified by encapsulated Cryptococcus species, and Pneumocystis pose significant fungal threats to the lung. Classically, fungal pneumonia occurs in immune compromised individuals, specifically in patients with HIV/AIDS, in patients with hematologic malignancies, in organ transplant recipients, and in patients treated with corticosteroids and targeted biologics that impair fungal immune surveillance in the lung. The emergence of fungal co-infections during severe influenza and COVID-19 underscores the impairment of fungus-specific host defense pathways in the lung by respiratory viruses and by medical therapies to treat viral infections. Beyond life-threatening invasive syndromes, fungal antigen exposure can exacerbate allergenic disease in the lung. In this review, we discuss emerging principles of lung-specific antifungal immunity, integrate the contributions and cooperation of lung epithelial, innate immune, and adaptive immune cells to mucosal barrier immunity, and highlight the pathogenesis of fungal-associated allergenic disease. Improved understanding of fungus-specific immunity in the respiratory tree has paved the way to develop improved diagnostic, pre-emptive, therapeutic, and vaccine approaches for fungal diseases of the lung.

Aspergillus-SARS-CoV-2 Coinfection: What Is Known?

COVID-19-associated pulmonary aspergillosis (CAPA) has had a high incidence. In addition, it has been associated with prolonged hospital stays, as well as several predisposing risk factors, such as fungal factors (nosocomial organism, the size of the conidia, and the ability of the Aspergillus spp. of colonizing the respiratory tract), environmental factors (remodeling in hospitals, use of air conditioning and negative pressure in intensive care units), comorbidities, and immunosuppressive therapies. In addition to these factors, SARS-CoV-2 per se is associated with significant dysfunction of the patient's immune system, involving both innate and acquired immunity, with reduced CD4+ and CD8+ T cell counts and cytokine storm. Therefore, this review aims to identify the factors influencing the fungus so that coinfection with SARS-CoV-2 can occur. In addition, we analyze the predisposing factors in the fungus, host, and the immune response alteration due to the pathogenicity of SARS-CoV-2 that causes the development of CAPA.

COVID-19 patients share common, corticosteroid-independent features of impaired host immunity to pathogenic molds

Patients suffering from coronavirus disease-2019 (COVID-19) are susceptible to deadly secondary fungal infections such as COVID-19-associated pulmonary aspergillosis and COVID-19-associated mucormycosis. Despite this clinical observation, direct experimental evidence for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)-driven alterations of antifungal immunity is scarce. Using an ex-vivo whole blood stimulation assay, we challenged blood from twelve COVID-19 patients with Aspergillus fumigatus and Rhizopus arrhizus antigens and studied the expression of activation, maturation, and exhaustion markers, as well as cytokine secretion. Compared to healthy controls, T-helper cells from COVID-19 patients displayed increased expression levels of the exhaustion marker PD-1 and weakened A. fumigatus- and R. arrhizus-induced activation. While baseline secretion of proinflammatory cytokines was massively elevated, whole blood from COVID-19 patients elicited diminished release of T-cellular (e.g., IFN-γ, IL-2) and innate immune cell-derived (e.g., CXCL9, CXCL10) cytokines in response to A. fumigatus and R. arrhizus antigens. Additionally, samples from COVID-19 patients showed deficient granulocyte activation by mold antigens and reduced fungal killing capacity of neutrophils. These features of weakened anti-mold immune responses were largely decoupled from COVID-19 severity, the time elapsed since diagnosis of COVID-19, and recent corticosteroid uptake, suggesting that impaired anti-mold defense is a common denominator of the underlying SARS-CoV-2 infection. Taken together, these results expand our understanding of the immune predisposition to post-viral mold infections and could inform future studies of immunotherapeutic strategies to prevent and treat fungal superinfections in COVID-19 patients.

“CAPA in Progress”: A New Real-Life Approach for the Management of Critically Ill COVID-19 Patients

(1) Background: COVID-19-associated pulmonary aspergillosis (CAPA) has worsened the prognosis of patients with pneumonia and acute respiratory distress syndrome admitted to the intensive care unit (ICU). The lack of specific diagnosis criteria is an obstacle to the timely initiation of appropriate antifungal therapy. Tracheal aspirate (TA) has been employed under special pandemic conditions. Galactomannan (GM) antigens are released during active fungal growth. (2) Methods: We proposed the term “CAPA in progress” (CAPA-IP) for diagnosis at an earlier stage by GM testing on TA in a specific population admitted to ICU presenting with clinical deterioration. A GM threshold ≥0.5 was set as the mycological inclusion criterion. This was followed by a pre-emptive short-course antifungal. (3) Results: We prospectively enrolled 200 ICU patients with COVID-19. Of these, 164 patients (82%) initially required invasive mechanical ventilation and GM was tested in TA in 93 patients. A subset of 19 patients (11.5%) fulfilled the CAPA-IP criteria at a median of 9 days after ICU admittance. The median GM value was 3.25 ± 2.82. CAPA-IP cases showed significantly higher ICU mortality [52.6% (10/19) vs. 34.5% (50/145), p = 0.036], as well as a much longer median ICU stay than those with a normal GM index [27 (7–64) vs. 11 (9–81) days, p = 0.008]. All cases were treated with a pre-emptive systemic antifungal for a median time of 19 (3–39) days. (4) Conclusions: CAPA-IP highlights a new real-life early approach in the field of fungal stewardship in ICU programs.

COVID-19-Associated Fungal Infections: An Urgent Need for Alternative Therapeutic Approach?

Secondary fungal infections may complicate the clinical course of patients affected by viral respiratory diseases, especially those admitted to intensive care unit. Hospitalized COVID-19 patients are at increased risk of fungal co-infections exacerbating the prognosis of disease due to misdiagnosis that often result in treatment failure and high mortality rate. COVID-19-associated fungal infections caused by predominantly Aspergillus and Candida species, and fungi of the order Mucorales have been reported from several countries to become significant challenge for healthcare system. Early diagnosis and adequate antifungal therapy is essential to improve clinical outcomes, however, drug resistance shows a rising trend highlighting the need for alternative therapeutic agents. The purpose of this review is to summarize the current knowledge on COVID-19-associated mycoses, treatment strategies and the most recent advancements in antifungal drug development focusing on peptides with antifungal activity.

Clinical and Imaging Features of COVID-19-Associated Pulmonary Aspergillosis

Background: COVID-19 superinfection by Aspergillus (COVID-19-associated aspergillosis, CAPA) is increasingly observed due to increased awareness and use of corticosteroids. The aim of this study is to compare clinical and imaging features between COVID-19 patients with and without associated pulmonary aspergillosis. Material and Methods: In this case–control study, hospitalized patients between March 2020 and March 2021 were evaluated. Two observers independently compared 105 chest CTs of 52 COVID-19 patients without pulmonary aspergillosis to 40 chest CTs of 13 CAPA patients. The following features were evaluated: lung involvement, predominant main pattern (ground glass opacity, crazy paving, consolidation) and additional lung and chest findings. Chronological changes in the abnormal extent upon CT and chronological changes in the main patterns were compared with mixed models. Patient-wise comparisons of additional features and demographic and clinical data were performed using Student’s t-test, Chi-squared test, Fisher’s exact tests and Wilcoxon rank-sum tests. Results: Compared to COVID-19 patients without pulmonary aspergillosis, CAPA patients were older (mean age (±SD): 70.3 (±7.8) versus 63.5 (±9.5) years (p = 0.01). The time-dependent evolution rates for consolidation (p = 0.02) and ground glass (p = 0.006) differed. In early COVID-19 disease, consolidation was associated with CAPA, whereas ground glass was less common. Chronological changes in the abnormal extent upon CT did not differ (p = 0.29). Regardless of the time point, bronchial wall thickening was observed more frequently in CAPA patients (p = 0.03). Conclusions: CAPA patients showed a tendency for consolidation in early COVID-19 disease. Bronchial wall thickening and higher patient age were associated with CAPA. The overall lung involvement was similar between both groups.

Coronavirus disease 2019 (COVID-19) associated pulmonary aspergillosis (CAPA): Re-framing the debate

Background

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) has been reported in ~5%–10% of critically ill COVID-19 patients. However, incidence varies widely (0%–33%) across hospitals, most cases are unproven, and CAPA definitions and clinical relevance are debated.

Methods

We reframed the debate by asking, what is the likelihood that patients with CAPA have invasive aspergillosis? We use diagnostic test performance in other clinical settings to estimate positive predictive values (PPVs) and negative predictive values (NPVs) of CAPA criteria for invasive aspergillosis in populations with varying CAPA incidence.

Results

In a population with CAPA incidence of 10%, anticipated PPV/NPV of diagnostic criteria are ~30%–60%/≥97%; ~3%–5% of tested cohort would be anticipated to have true invasive aspergillosis. If CAPA incidence is 2%–3%, anticipated PPV and NPV are ~8%–30%/>99%.

Conclusions

Depending on local epidemiology and clinical details of a given case, PPVs and NPVs may be useful in guiding antifungal therapy. We incorporate this model into a stepwise strategy for diagnosing and managing CAPA.

Coinfections in Patients with Cancer and COVID-19: A COVID-19 and Cancer Consortium (CCC19) Study

Background

The frequency of coinfections and their association with outcomes have not been adequately studied among patients with cancer and coronavirus disease 2019 (COVID-19), a high-risk group for coinfection.

Methods

We included adult (≥18 years) patients with active or prior hematologic or invasive solid malignancies and laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection, using data from the COVID-19 and Cancer Consortium (CCC19, NCT04354701). We captured coinfections within ±2 weeks from diagnosis of COVID-19, identified factors cross-sectionally associated with risk of coinfection, and quantified the association of coinfections with 30-day mortality.

Results

Among 8765 patients (hospitalized or not; median age, 65 years; 47.4% male), 16.6% developed coinfections: 12.1% bacterial, 2.1% viral, 0.9% fungal. An additional 6.4% only had clinical diagnosis of a coinfection. The adjusted risk of any coinfection was positively associated with age >50 years, male sex, cardiovascular, pulmonary, and renal comorbidities, diabetes, hematologic malignancy, multiple malignancies, Eastern Cooperative Oncology Group Performance Status, progressing cancer, recent cytotoxic chemotherapy, and baseline corticosteroids; the adjusted risk of superinfection was positively associated with tocilizumab administration. Among hospitalized patients, high neutrophil count and C-reactive protein were positively associated with bacterial coinfection risk, and high or low neutrophil count with fungal coinfection risk. Adjusted mortality rates were significantly higher among patients with bacterial (odds ratio [OR], 1.61; 95% CI, 1.33–1.95) and fungal (OR, 2.20; 95% CI, 1.28–3.76) coinfections.

Conclusions

Viral and fungal coinfections are infrequent among patients with cancer and COVID-19, with the latter associated with very high mortality rates. Clinical and laboratory parameters can be used to guide early empiric antimicrobial therapy, which may improve clinical outcomes.

Association of COVID-19-Associated Pulmonary Aspergillosis with Cytomegalovirus Replication: A Case–control Study

Introduction: Cytomegalovirus (CMV) infection is a well-known factor associated with invasive aspergillosis in immunocompromised hosts. However, its association with COVID-19-associated pulmonary aspergillosis (CAPA) has not been described. We aimed to examine the possible link between CMV replication and CAPA occurrence. Methods: A single-center, retrospective case–control study was conducted. A case was defined as a patient diagnosed with CAPA according to 2020 ECMM/ISHAM consensus criteria. Two controls were selected for each case among critically ill COVID-19 patients. Results: In total, 24 CAPA cases were included, comprising 14 possible CAPA and 10 probable CAPA. Additionally, 48 matched controls were selected. CMV replication was detected more frequently in CAPA than in controls (75.0% vs. 35.4%, p = 0.002). Probable CMV end-organ disease was more prevalent in CAPA (20.8% vs. 4.2%, p = 0.037). After adjusting for possible confounding factors, CMV replication persisted strongly associated with CAPA (OR 8.28 95% CI 1.90–36.13, p = 0.005). Among 11 CAPA cases with CMV PCR available prior to CAPA, in 9 (81.8%) cases, CMV replication was observed prior to CAPA diagnosis. Conclusions: Among critically ill COVID-19 patients, CMV replication was associated with CAPA and could potentially be considered a harbinger of CAPA. Further studies are needed to confirm this association.

Fungal infections in mechanically ventilated patients with COVID-19 during the first wave: the French multicentre MYCOVID study

Background

Patients with severe COVID-19 have emerged as a population at high risk of invasive fungal infections (IFIs). However, to our knowledge, the prevalence of IFIs has not yet been assessed in large populations of mechanically ventilated patients. We aimed to identify the prevalence, risk factors, and mortality associated with IFIs in mechanically ventilated patients with COVID-19 under intensive care.

Methods

We performed a national, multicentre, observational cohort study in 18 French intensive care units (ICUs). We retrospectively and prospectively enrolled adult patients (aged ≥18 years) with RT-PCR-confirmed SARS-CoV-2 infection and requiring mechanical ventilation for acute respiratory distress syndrome, with all demographic and clinical and biological follow-up data anonymised and collected from electronic case report forms. Patients were systematically screened for respiratory fungal microorganisms once or twice a week during the period of mechanical ventilation up to ICU discharge. The primary outcome was the prevalence of IFIs in all eligible participants with a minimum of three microbiological samples screened during ICU admission, with proven or probable (pr/pb) COVID-19-associated pulmonary aspergillosis (CAPA) classified according to the recent ECMM/ISHAM definitions. Secondary outcomes were risk factors of pr/pb CAPA, ICU mortality between the pr/pb CAPA and non-pr/pb CAPA groups, and associations of pr/pb CAPA and related variables with ICU mortality, identified by regression models. The MYCOVID study is registered with ClinicalTrials.gov, NCT04368221.

Findings

Between Feb 29 and July 9, 2020, we enrolled 565 mechanically ventilated patients with COVID-19. 509 patients with at least three screening samples were analysed (mean age 59·4 years [SD 12·5], 400 [79%] men). 128 (25%) patients had 138 episodes of pr/pb or possible IFIs. 76 (15%) patients fulfilled the criteria for pr/pb CAPA. According to multivariate analysis, age older than 62 years (odds ratio [OR] 2·34 [95% CI 1·39–3·92], p=0·0013), treatment with dexamethasone and anti-IL-6 (OR 2·71 [1·12–6·56], p=0·027), and long duration of mechanical ventilation (>14 days; OR 2·16 [1·14–4·09], p=0·019) were independently associated with pr/pb CAPA. 38 (7%) patients had one or more other pr/pb IFIs: 32 (6%) had candidaemia, six (1%) had invasive mucormycosis, and one (<1%) had invasive fusariosis. Multivariate analysis of associations with death, adjusted for candidaemia, for the 509 patients identified three significant factors: age older than 62 years (hazard ratio [HR] 1·71 [95% CI 1·26–2·32], p=0·0005), solid organ transplantation (HR 2·46 [1·53–3·95], p=0·0002), and pr/pb CAPA (HR 1·45 [95% CI 1·03–2·03], p=0·033). At time of ICU discharge, survival curves showed that overall ICU mortality was significantly higher in patients with pr/pb CAPA than in those without, at 61·8% (95% CI 50·0–72·8) versus 32·1% (27·7–36·7; p<0·0001).

Interpretation

This study shows the high prevalence of invasive pulmonary aspergillosis and candidaemia and high mortality associated with pr/pb CAPA in mechanically ventilated patients with COVID-19. These findings highlight the need for active surveillance of fungal pathogens in patients with severe COVID-19.

Funding

Pfizer.

Corticosteroids as risk factor for COVID-19-associated pulmonary aspergillosis in intensive care patients

PURPOSE

Corticosteroids, in particular dexamethasone, are one of the primary treatment options for critically ill COVID-19 patients. However, there are a growing number of cases that involve COVID-19-associated pulmonary aspergillosis (CAPA), and it is unclear whether dexamethasone represents a risk factor for CAPA. Our aim was to investigate a possible association of the recommended dexamethasone therapy with a risk of CAPA.

METHODS

We performed a study based on a cohort of COVID-19 patients treated in 2020 in our 13 intensive care units at Charité Universitätsmedizin Berlin. We used ECMM/ISHM criteria for the CAPA diagnosis and performed univariate and multivariable analyses of clinical parameters to identify risk factors that could result in a diagnosis of CAPA.

RESULTS

Altogether, among the n = 522 intensive care patients analyzed, n = 47 (9%) patients developed CAPA. CAPA patients had a higher simplified acute physiology score (SAPS) (64 vs. 53, p < 0.001) and higher levels of IL-6 (1,005 vs. 461, p < 0.008). They more often had severe acute respiratory distress syndrome (ARDS) (60% vs. 41%, p = 0.024), renal replacement therapy (60% vs. 41%, p = 0.024), and they were more likely to die (64% vs. 48%, p = 0.049). The multivariable analysis showed dexamethasone (OR 3.110, CI95 1.112-8.697) and SAPS (OR 1.063, CI95 1.028-1.098) to be independent risk factors for CAPA.

CONCLUSION

In our study, dexamethasone therapy as recommended for COVID-19 was associated with a significant three times increase in the risk of CAPA.

TRIAL REGISTRATION

Registration number DRKS00024578, Date of registration March 3rd, 2021.

COVID-19-Associated Pulmonary Aspergillosis in a Tertiary Hospital

Our study aims to assess the prevalence of CAPA (COVID-19-associated pulmonary aspergillosis) and describe the associated risk factors and their impact on mortality. A prospective study was conducted. We included patients with COVID-19 disease who were admitted to the ICU with a diagnosis of respiratory failur. Mycological culture and other biomarkers (calcofluor staining, LFD, LFA, PCR, GM, and B-D-glucan) were performed. A total of 300 patients were included in the study. Thirty-five patients were diagnosed with CAPA (prevalence 11.7%). During admission, 57 patients died (19%), and, in the group of CAPA patients, mortality was 31.4%. In multivariate analysis, independent risk factors associated with CAPA diagnosis were age (OR: 1.05; 95% CI 1.01–1.09; p = 0.037), chronic lung disease (OR: 3.85; 95% CI 1.02–14.9; p = 0.049) and treatment with tocilizumab during admission (OR: 14.5; 95% 6.1–34.9; p = 0.001). Factors independently associated with mortality were age (OR: 1.06; 95% CI 1.01–1.11; p = 0.014) and CAPA diagnosis during admission (OR: 3.34; 95% CI 1.38–8.08; p = 0.007). CAPA is an infection that appears in many patients with COVID-19 disease. CAPA is associated with high mortality rates, which may be reduced by early diagnosis and initiation of appropriate antifungal therapy, so screening of COVID-19 ARDS (acute respiratory distress syndrome) patients for CAPA is essential.

Emerging Fungal Infections: New Species, New Names, and Antifungal Resistance

Background

Infections caused by fungi can be important causes of morbidity and mortality in certain patient populations, including those who are highly immunocompromised or critically ill. Invasive mycoses can be caused by well-known species, as well as emerging pathogens, including those that are resistant to clinically available antifungals.

Content

This review highlights emerging fungal infections, including newly described species, such as Candida auris, and those that having undergone taxonomic classification and were previously known by other names, including Blastomyces and Emergomyces species, members of the Rasamsonia argillacea species complex, Sporothrix brasiliensis, and Trichophyton indotinae. Antifungal resistance also is highlighted in several of these emerging species, as well as in the well-known opportunistic pathogen Aspergillus fumigatus. Finally, the increased recognition and importance of fungal co-infections with respiratory pathogens, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is discussed.

Summary

Both clinicians and clinical microbiology laboratories should remain vigilant regarding emerging fungal infections. These may be difficult both to diagnose and treat due to the lack of experience of clinicians and laboratory personnel with these organisms and the infections they may cause. Many of these fungal infections have been associated with poor clinical outcomes, either due to inappropriate therapy or the development of antifungal resistance.

Invasive pulmonary aspergillosis in critically ill patients with COVID-19 in Australia: implications for screening and treatment

We report four cases of invasive pulmonary aspergillus co-infection in patients with coronavirus disease 2019 (COVID-19) infection and acute respiratory distress syndrome requiring intensive care unit (ICU) admission. Aspergillus fumigatus and Aspergillus terreus were isolated, with early infection onset following ICU admission. Clinicians should be aware of invasive pulmonary aspergillosis in ICU patients with COVID-19 infection, particularly those receiving dexamethasone. We propose screening of these high-risk patients with twice-weekly fungal culture from tracheal aspirate and, if feasible, Aspergillus polymerase chain reaction. Diagnosis is challenging and antifungal treatment should be considered in critically ill patients who have new or worsening pulmonary changes on chest imaging and mycological evidence of infection.

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.

Risk Factors for Invasive Aspergillosis in Patients Admitted to the Intensive Care Unit With Coronavirus Disease 2019: A Multicenter Retrospective Study

Background: Invasive pulmonary aspergillosis (IPA) is a life-threatening complication in coronavirus disease 2019 (COVID-19) patients admitted to intensive care units (ICUs), but risk factors for COVID-19-associated IPA (CAPA) have not been fully characterized. The aim of the current study was to identify factors associated with CAPA, and assess long-term mortality. Methods: A retrospective cohort study of adult COVID-19 patients admitted to ICUs from six hospitals was conducted in Hubei, China. CAPA was diagnosed via composite clinical criteria. Demographic information, clinical variables, and 180-day outcomes after the diagnosis of CAPA were analyzed. Results: Of 335 critically ill patients with COVID-19, 78 (23.3%) developed CAPA within a median of 20.5 days (range 13.0-42.0 days) after symptom onset. Compared to those without CAPA, CAPA patients were more likely to have thrombocytopenia (50 vs. 19.5%, p < 0.001) and secondary bacterial infection prior to being diagnosed with CAPA (15.4 vs. 6.2%, p = 0.013), and to receive vasopressors (37.2 vs. 8.6%, p < 0.001), higher steroid dosages (53.9 vs. 34.2%, p = 0.002), renal replacement therapy (37.2 vs. 13.6%, p < 0.001), and invasive mechanical ventilation (57.7 vs. 35.8%, p < 0.001). In multivariate analysis incorporating hazard ratios (HRs) and confidence intervals (CIs), thrombocytopenia (HR 1.98, 95% CI 1.16-3.37, p = 0.012), vasopressor use (HR 3.57, 95% CI 1.80-7.06, p < 0.001), and methylprednisolone use at a daily dose ≥ 40 mg (HR 1.69, 95% CI 1.02-2.79, p = 1.02-2.79) before CAPA diagnosis were independently associated with CAPA. Patients with CAPA had longer median ICU stays (17 days vs. 12 days, p = 0.007), and higher 180-day mortality (65.4 vs. 33.5%, p < 0.001) than those without CAPA. Conclusions: Thrombocytopenia, vasopressor use, and corticosteroid treatment were significantly associated with increased risk of incident IPA in COVID-19 patients admitted to ICUs. The occurrence of CAPA may increase the likelihood of long-term COVID-19 mortality.

Aspergillus Test Profiles and Mortality in Critically Ill COVID-19 Patients

The literature regarding COVID-19-associated pulmonary aspergillosis (CAPA) has shown conflicting observations, including survival of CAPA patients not receiving antifungal therapy and discrepancy between CAPA diagnosis and autopsy findings. To gain insight into the pathophysiology of CAPA, we performed a case-control study in which we compared Aspergillus test profiles in CAPA patients and controls in relation to intensive care unit (ICU) mortality. This was a multinational case-control study in which Aspergillus test results, use of antifungal therapy, and mortality were collected from critically ill COVID-19 patients. Patients were classified using the 2020 European Confederation for Medical Mycology and the International Society for Human and Animal Mycology (ECMM/ISHAM) consensus case definitions. We analyzed 219 critically ill COVID-19 cases, including 1 proven, 38 probable, 19 possible CAPA cases, 21 Aspergillus-colonized patients, 7 patients only positive for serum (1,3)-β-d-glucan (BDG), and 133 cases with no evidence of CAPA. Mortality was 53.8% in CAPA patients compared to 24.1% in patients without CAPA (P = 0.001). Positive serum galactomannan (GM) and BDG were associated with increased mortality compared to serum biomarker-negative CAPA patients (87.5% versus 41.7%, P = 0.046; 90.0% versus 42.1%, P = 0.029, respectively). For each point increase in GM or 10-point BDG serum concentration, the odds of death increased (GM, odds ratio [OR] 10.208, 95% confidence interval [CI], 1.621 to 64.291, P = 0.013; BDG, OR, 1.247, 95% CI, 1.029 to 1.511, P = 0.024). CAPA is a complex disease, probably involving a continuum of respiratory colonization, tissue invasion, and angioinvasion. Serum biomarkers are useful for staging CAPA disease progression and, if positive, indicate angioinvasion and a high probability of mortality. There is need for a biomarker that distinguishes between respiratory tract colonization and tissue-invasive CAPA disease.

Practice Guidelines for the Diagnosis of COVID-19-Associated Pulmonary Aspergillosis in an Intensive Care Setting

Coronavirus disease-2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is a new disease characterized by secondary Aspergillus mold infection in patients with COVID-19. It primarily affects patients with COVID-19 in critical state with acute respiratory distress syndrome, requiring intensive care and mechanical ventilation. CAPA has a higher mortality rate than COVID-19, posing a serious threat to affected individuals. COVID-19 is a potential risk factor for CAPA and has already claimed a massive death toll worldwide since its outbreak in December 2019. Its second wave is currently progressing towards a peak, while the third wave of this devastating pandemic is expected to follow. Therefore, an early and accurate diagnosis of CAPA is of utmost importance for effective clinical management of this highly fatal disease. However, there are no uniform criteria for diagnosing CAPA in an intensive care setting. Therefore, based on a review of existing information and our own experience, we have proposed new criteria in the form of practice guidelines for diagnosing CAPA, focusing on the points relevant for intensivists and pulmonary and critical care physicians. The main highlights of these guidelines include the role of CAPA-appropriate test specimens, clinical risk factors, computed tomography of the thorax, and non-culture-based indirect and direct mycological evidence for diagnosing CAPA in the intensive care unit. These guidelines classify the diagnosis of CAPA into suspected, possible, and probable categories to facilitate clinical decision-making. We hope that these practice guidelines will adequately address the diagnostic challenges of CAPA, providing an easy-to-use and practical algorithm to clinicians for rapid diagnosis and clinical management of the disease.

Incidence and Risk Factors of COVID-19-Associated Pulmonary Aspergillosis in Intensive Care Unit-A Monocentric Retrospective Observational Study

Coronavirus disease 2019 (COVID-19)-associated pulmonary aspergillosis (CAPA) is an increasingly recognized complication of COVID-19 and is associated with significant over-mortality. We performed a retrospective monocentric study in patients admitted to the intensive care unit (ICU) for respiratory insufficiency due to COVID-19 from March to December 2020, in order to evaluate the incidence of CAPA and the associated risk factors. We also analysed the diagnostic approach used in our medical centre for CAPA diagnosis. We defined CAPA using recently proposed consensus definitions based on clinical, radiological and microbiological criteria. Probable cases of CAPA occurred in 9 out of 141 patients included in the analysis (6.4%). All cases were diagnosed during the second wave of the pandemic. We observed a significantly higher realization rate of bronchoalveolar lavage (BAL) (51.1% vs. 28.6%, p = 0.01) and Aspergillus testing (through galactomannan, culture, PCR) on BAL samples during the second wave (p < 0.0001). The testing for Aspergillus in patients meeting the clinical and radiological criteria of CAPA increased between the two waves (p < 0.0001). In conclusion, we reported a low but likely underestimated incidence of CAPA in our population. A greater awareness and more systematic testing for Aspergillus are necessary to assess the real incidence and characteristics of CAPA.

COVID-Associated Pulmonary Aspergillosis and Its Related Outcomes: A Single-Center Prospective Observational Study

Background and objective Invasive pulmonary aspergillosis (IPA) is a frequent complication among neutropenic patients. It is increasingly being reported in critical coronavirus disease 2019 (COVID-19) patients requiring ICU admission and invasive mechanical ventilation (IMV) and is known as COVID-associated pulmonary aspergillosis (CAPA). We conducted this large prospective observational study to determine the frequency of CAPA and its outcomes in the ICU population. Methodology This was a prospective observational study. We recruited 307 reverse transcription-polymerase chain reaction (RT-PCR)-confirmed cases of severe COVID-19 pneumonia requiring IMV. We excluded those who did not require IMV or had been transferred out to other hospitals. The Chi-square test was applied to find the association between categorical variables. A p-value of <0.05 was considered statistically significant. Results Out of the 307 cases of mechanically ventilated COVID-19 pneumonia, 61 had probable CAPA. The median age was 60 years. Malignancy and cirrhosis were significant risk factors associated with CAPA (p=<0.001, 0.001, respectively). Aspergillus fumigatus was detected in 78.7% of the cases. The median length of ICU stay was 11 days [interquartile range (IQR): 4-14]. Among CAPA cases, 70.5% developed septic shock and required ionotropic support. Among 61 probable cases of CAPA, 91.8% did not survive and there was a strong correlation between CAPA and ICU mortality (p=0.001). Conclusion We concluded that CAPA is a fatal complication of severe COVID-19 pneumonia and is associated with increased mortality.

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.

Overview on the Prevalence of Fungal Infections, Immune Response, and Microbiome Role in COVID-19 Patients

Patients with severe COVID-19, such as individuals in intensive care units (ICU), are exceptionally susceptible to bacterial and fungal infections. The most prevalent fungal infections are aspergillosis and candidemia. Nonetheless, other fungal species (for instance, Histoplasma spp., Rhizopus spp., Mucor spp., Cryptococcus spp.) have recently been increasingly linked to opportunistic fungal diseases in COVID-19 patients. These fungal co-infections are described with rising incidence, severe illness, and death that is associated with host immune response. Awareness of the high risks of the occurrence of fungal co-infections is crucial to downgrade any arrear in diagnosis and treatment to support the prevention of severe illness and death directly related to these infections. This review analyses the fungal infections, treatments, outcome, and immune response, considering the possible role of the microbiome in these patients. The search was performed in Medline (PubMed), using the words "fungal infections COVID-19", between 2020-2021.

Facile Homobifunctional Imidoester Modification of Advanced Nanomaterials for Enhanced Antibiotic Synergistic Effect

Resistance to antibiotics because of misuse and overuse is one of the greatest public health challenges worldwide. Despite the introduction of advanced nanotechnology in the production of antibiotics, the choice of appropriate medicines is limited due to side effects such as blood coagulation, toxicity, low efficacy, and low biocompatibility; therefore, novel nanomaterial composites are required to counter these repercussions. We first introduce a facile method for synthesizing a homobifunctional imidoester-coated nanospindle (HINS) zinc oxide composite for enhancement of antibiotic efficacy and reduction of toxicity and blood coagulation. The antibiotic efficacy of the composites is twice that of commercialized zinc nanoparticles; in addition, they have good biocompatibility, have increased surface charge and solubility owing to the covalent acylation groups of HI, and produce a large number of Zn⁺ ions and defensive reactive oxygen species (ROS) that effectively kill bacteria and fungi. The synergistic effect of a combination therapy with the HINS composite and itraconazole shows more than 90% destruction of fungi in treatments with low dosage with no cytotoxicity or coagulation evident in intravenous administration in in vitro and in vivo experiments. Thus, HINS composites are useful in reducing the effect of misuse and overuse of antibiotics in the medical field.

A review of significance of Aspergillus detection in airways of ICU COVID-19 patients

It is now well known that patients with SARS-CoV-2 infection admitted in ICU and mechanically ventilated are at risk of developing invasive pulmonary aspergillosis (IPA). Nevertheless, symptomatology of IPA is often atypical in mechanically ventilated patients, and radiological aspects in SARS-CoV-2 pneumonia and IPA are difficult to differentiate. In this context, the significance of the presence of Aspergillus in airway specimens (detected by culture, galactomannan antigen or specific PCR) remains to be fully understood. To decipher the relevance of the detection of Aspergillus, we performed a comprehensive review of all published cases of respiratory Aspergillus colonisation and IPA in COVID-19 patients. The comparison of patients receiving or not antifungal treatment allowed us to highlight the most important criteria for the decision to treat. The comparison of surviving and non-surviving patients made it possible to unveil criteria associated with mortality that should be taken into account in the treatment decision.

Impact of Inflammatory Response Modifiers on the Incidence of Hospital-Acquired Infections in Patients with COVID-19

Introduction

The study aim was to assess the influence of inflammatory response modifiers, including anti-interleukin-6 (IL-6) biologics and corticosteroids, on the incidence of hospital-acquired infections in patients with coronavirus disease 2019 (COVID-19).

Methods

Case–control study performed at a university hospital from February 26 to May 26, 2020. Cases were defined as patients with COVID-19 who developed hospital-acquired infections. For each case, two controls were selected among patients without infections. Cases and controls were matched obeying three criteria in a hierarchical sequence: length of hospital stay up until the first infection; comorbidity; and need for Intensive care unit (ICU) admission. Conditional logistic regression analysis was used to estimate the association of exposures with being a case.

Results

A total of 71 cases and 142 controls were included. Independent predictors for acquiring a hospital infection were chronic liver disease [odds ratio (OR) 16.56, 95% CI 1.87–146.5, p = 0.012], morbid obesity (OR 6.11, 95% CI 1.06–35.4, p = 0.043), current or past smoking (OR 4.15, 95% CI 1.45–11.88, p = 0.008), exposure to hydroxychloroquine (OR 0.2, 95% CI 0.041–1, p = 0.053), and invasive mechanical ventilation (OR 61.5, 95% CI 11.08–341, p ≤ 0.0001).

Conclusions

Inflammatory response modifiers had no influence on acquisition of nosocomial infections in admitted patients with COVID-19. Hospital-acquired infections primarily occurred in the critically ill and invasive mechanical ventilation was the main exposure conferring risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00477-9.

Comparison of clinical features and outcomes in COVID-19 and influenza pneumonia patients requiring intensive care unit admission

BACKGROUND

Little is known in distinguishing clinical features and outcomes between coronavirus disease-19 (COVID-19) and influenza (FLU).

MATERIALS/METHODS

Retrospective, single-centre study including patients with COVID-19 or FLU pneumonia admitted to the Intensive care Unit (ICU) of Policlinico Umberto I (Rome). Aims were: (1) to assess clinical features and differences of patients with COVID-19 and FLU, (2) to identify clinical and/or laboratory factors associated with FLU or COVID-19 and (3) to evaluate 30-day mortality, bacterial superinfections, thrombotic events and invasive pulmonary aspergillosis (IPA) in patients with FLU versus COVID-19.

RESULTS

Overall, 74 patients were included (19, 25.7%, FLU and 55, 74.3%, COVID-19), median age 67 years (58-76). COVID-19 patients were more male (p = 0.013), with a lower percentage of COPD (Chronic Obstructive Pulmonary Disease) and chronic kidney disease (CKD) (p = 0.001 and p = 0.037, respectively) than FLU. SOFA score was higher (p = 0.020) and lymphocytes were significantly lower in FLU than in COVID-19 [395.5 vs 770.0 cells/mmc, p = 0.005]. At multivariable analysis, male sex (OR 6.1, p < 0.002), age > 65 years (OR 2.4, p = 0.024) and lymphocyte count > 725 cells/mmc at ICU admission (OR 5.1, p = 0.024) were significantly associated with COVID-19, whereas CKD and COPD were associated with FLU (OR 0.1 and OR 0.16, p = 0.020 and p < 0.001, respectively). No differences in mortality, bacterial superinfections and thrombotic events were observed, whereas IPA was mostly associated with FLU (31.5% vs 3.6%, p = 0.0029).

CONCLUSIONS

In critically ill patients, male sex, age > 65 years and lymphocytes > 725 cells/mmc are related to COVID-19. FLU is associated with a significantly higher risk of IPA than COVID-19.

The Complexity of Co-Infections in the Era of COVID-19

The current frequency of COVID-19 in a pandemic era ensures that co-infections with a variety of co-pathogens will occur. Generally, there is a low rate of bonafide co-infections in early COVID-19 pulmonary infection as currently appreciated. Reports of high co-infection rates must be tempered by limitations in current diagnostic methods since amplification technologies do not necessarily confirm live pathogen and may be subject to considerable laboratory variation. Some laboratory methods may not exclude commensal microbes. Concurrent serodiagnoses have long been of concern for accuracy in these contexts. Presumed virus co-infections are not specific to COVID-19. The association of influenza viruses and SARS-CoV-2 in co-infection has been considerably variable during influenza season. Other respiratory virus co-infections have generally occurred in less than 10% of COVID-19 patients. Early COVID-19 disease is more commonly associated with bacterial co-pathogens that typically represent usual respiratory micro-organisms. Late infections, especially among severe clinical presentations, are more likely to be associated with nosocomial or opportunistic pathogens given the influence of treatments that can include antibiotics, antivirals, immunomodulating agents, blood products, immunotherapy, steroids, and invasive procedures. As anticipated, hospital care carries risk for multi-resistant bacteria. Overall, co-pathogen identification is linked with longer hospital stay, greater patient complexity, and adverse outcomes. As for other viral infections, a general reduction in the use of empiric antibiotic treatment is warranted. Further insight into co-infections with COVID-19 will contribute overall to effective antimicrobial therapies and disease control.

When Uncontrolled Diabetes Mellitus and Severe COVID-19 Converge: The Perfect Storm for Mucormycosis

Mucormycosis (MCR) has been increasingly described in patients with coronavirus disease 2019 (COVID-19) but the epidemiological factors, presentation, diagnostic certainty, and outcome of such patients are not well described. We review the published COVID-19-associated mucormycosis (CAMCR) cases (total 41) to identify risk factors, clinical features, and outcomes. CAMCR was typically seen in patients with diabetes mellitus (DM) (94%) especially the ones with poorly controlled DM (67%) and severe or critical COVID-19 (95%). Its presentation was typical of MCR seen in diabetic patients (mostly rhino-orbital and rhino-orbital-cerebral presentation). In sharp contrast to reported COVID-associated aspergillosis (CAPA) cases, nearly all CAMCR infections were proven (93%). Treating physicians should have a high suspicion for CAMCR in patients with uncontrolled diabetes mellitus and severe COVID-19 presenting with rhino-orbital or rhino-cerebral syndromes. CAMR is the convergence of two storms, one of DM and the other of COVID-19.