Systematic screening for COVID-19 associated invasive aspergillosis in ICU patients by culture and PCR on tracheal aspirate

Is there an interest in systematic serum screening for aspergillosis in COVID-19 patients in a medical ward?

PURPOSE

We evaluated the interest of systematic screening of serum fungal markers in patients hospitalized in a medical ward.

METHODS

We retrospectively analyzed all patients hospitalized in our infectious disease department from October 1st to October 31st, 2020 for COVID-19 without prior ICU admission, and for whom systematic screening of serum fungal markers was performed.

RESULTS

Thirty patients were included. The majority of patients received corticosteroids (96.7%). The galactomannan antigen assay was positive for 1/30 patients at D0, and 0/24, 0/16, 0/13 and 0/2 at D4, D7, D10 and D14 respectively. 1,3-ß-D-glucan was positive for 0/30, 1/24, 1/12, 0/12, 0/2 at D0, D4, D7, D10 and D14 respectively. No Aspergillus fumigatus PCR was positive. No cases of aspergillosis were retained.

CONCLUSION

Our study does not support the interest of systematic screening of fungal markers in immunocompetent patients with COVID-19 in a conventional unit.

Prospective and systematic screening for invasive aspergillosis in the ICU during the COVID-19 pandemic, a proof of principle for future pandemics

The diagnostic performance of a prospective, systematic screening strategy for COVID-19 associated pulmonary aspergillosis (CAPA) during the COVID-19 pandemic was investigated. Patients with COVID-19 admitted to the ICU were screened for CAPA twice weekly by collection of tracheal aspirate (TA) for Aspergillus culture and PCR. Subsequently, bronchoalveolar lavage (BAL) sampling was performed in patients with positive screening results and clinical suspicion of infection. Patient data were collected from April 2020-February 2022. Patients were classified according to 2020 ECMM/ISHAM consensus criteria. In total, 126/370 (34%) patients were positive in screening and CAPA frequency was 52/370 (14%) (including 13 patients negative in screening). CAPA was confirmed in 32/43 (74%) screening positive patients who underwent BAL sampling. ICU mortality was 62% in patients with positive screening and confirmed CAPA, and 31% in CAPA cases who were screening negative. The sensitivity, specificity, positive and negative predictive value (PPV & NPV) of screening for CAPA were 0.71, 0.73, 0.27, and 0.95, respectively. The PPV was higher if screening was culture positive compared to PCR positive only, 0.42 and 0.12 respectively. CAPA was confirmed in 74% of screening positive patients, and culture of TA had a better diagnostic performance than PCR. Positive screening along with clinical manifestations appeared to be a good indication for BAL sampling since diagnosis of CAPA was confirmed in most of these patients. Prospective, systematic screening allowed to quickly gain insight into the epidemiology of fungal superinfections during the pandemic and could be applicable for future pandemics.

Risk factors and the value of microbiological examinations of COVID-19 associated pulmonary aspergillosis in critically ill patients in intensive care unit: the appropriate microbiological examinations are crucial for the timely diagnosis of CAPA

Introduction

During the Omicron pandemic in China, a significant proportion of patients with Coronavirus Disease 2019 (COVID-19) associated pulmonary aspergillosis (CAPA) necessitated admission to intensive care unit (ICU) and experienced a high mortality. To explore the clinical risk factors and the application/indication of microbiological examinations of CAPA in ICU for timely diagnosis are very important.

Methods

This prospective study included patients with COVID-19 admitted to ICU between December 1, 2022, and February 28, 2023. The clinical data of influenza-associated pulmonary aspergillosis (IAPA) patients from the past five consecutive influenza seasons (November 1, 2017, to March 31, 2022) were collected for comparison. The types of specimens and methods used for microbiological examinations were also recorded to explore the efficacy in early diagnosis.

Results

Among 123 COVID-19 patients, 36 (29.3%) were diagnosed with probable CAPA. CAPA patients were more immunosuppressed, in more serious condition, required more advanced respiratory support and had more other organ comorbidities. Solid organ transplantation, APACHEII score ≥20 points, 5 points ≤SOFA score <10 points were independent risk factors for CAPA. Qualified lower respiratory tract specimens were obtained from all patients, and 84/123 (68.3%) patients underwent bronchoscopy to obtain bronchoalveolar lavage fluid (BALF) specimens. All patients' lower respiratory tract specimens underwent fungal smear and culture; 79/123 (64.2%) and 69/123 (56.1%) patients underwent BALF galactomannan (GM) and serum GM detection, respectively; metagenomic next-generation sequencing (mNGS) of the BALF was performed in 62/123 (50.4%) patients. BALF GM had the highest diagnostic sensitivity (84.9%), the area under the curve of the mNGS were the highest (0.812).

Conclusion

The incidence of CAPA was extremely high in patients admitted to the ICU. CAPA diagnosis mainly depends on microbiological evidence owing to non-specific clinical manifestations, routine laboratory examinations, and CT findings. The bronchoscopy should be performed and the BALF should be obtained as soon as possible. BALF GM are the most suitable microbiological examinations for the diagnosis of CAPA. Due to the timely and accuracy result of mNGS, it could assist in early diagnosis and might be an option in critically ill CAPA patients.

Microbiological Non-Culture-Based Methods for Diagnosing Invasive Pulmonary Aspergillosis in ICU Patients

The diagnosis of invasive pulmonary aspergillosis (IPA) in intensive care unit (ICU) patients is crucial since most clinical signs are not specific to invasive fungal infections. To detect an IPA, different criteria should be considered. Next to host factors and radiological signs, microbiological criteria should be fulfilled. For microbiological diagnostics, different methods are available. Next to the conventional culture-based approaches like staining and culture, non-culture-based methods can increase sensitivity and improve time-to-result. Besides fungal biomarkers, like galactomannan and (1→3)-β-D-glucan as nonspecific tools, molecular-based methods can also offer detection of resistance determinants. The detection of novel biomarkers or targets is promising. In this review, we evaluate and discuss the value of non-culture-based microbiological methods (galactomannan, (1→3)-β-D-glucan, Aspergillus PCR, new biomarker/targets) for diagnosing IPA in ICU patients.

Recommendations and guidelines for the diagnosis and management of Coronavirus Disease-19 (COVID-19) associated bacterial and fungal infections in Taiwan

Coronavirus disease-19 (COVID-19) is an emerging infectious disease caused by SARS-CoV-2 that has rapidly evolved into a pandemic to cause over 600 million infections and more than 6.6 million deaths up to Nov 25, 2022. COVID-19 carries a high mortality rate in severe cases. Co-infections and secondary infections with other micro-organisms, such as bacterial and fungus, further increases the mortality and complicates the diagnosis and management of COVID-19. The current guideline provides guidance to physicians for the management and treatment of patients with COVID-19 associated bacterial and fungal infections, including COVID-19 associated bacterial infections (CABI), pulmonary aspergillosis (CAPA), candidiasis (CAC) and mucormycosis (CAM). Recommendations were drafted by the 7th Guidelines Recommendations for Evidence-based Antimicrobial agents use Taiwan (GREAT) working group after review of the current evidence, using the grading of recommendations assessment, development, and evaluation (GRADE) methodology. A nationwide expert panel reviewed the recommendations in March 2022, and the guideline was endorsed by the Infectious Diseases Society of Taiwan (IDST). This guideline includes the epidemiology, diagnostic methods and treatment recommendations for COVID-19 associated infections. The aim of this guideline is to provide guidance to physicians who are involved in the medical care for patients with COVID-19 during the ongoing COVID-19 pandemic.

Cryptococcosis among hospitalised patients with COVID-19: A multicentre research network study

It is unclear if there is an association between COVID-19 and cryptococcosis. Therefore, this study aimed to describe the clinical features, risk factors, and outcomes associated with cryptococcosis in hospitalised patients with COVID-19. The objectives of this study were to determine the incidence of and examine factors associated with cryptococcosis after a diagnosis of COVID-19. We used TriNetX to identify and sort patients 18 years and older hospitalised with COVID-19 into two cohorts based on the presence or absence of a diagnosis of cryptococcosis following diagnosis of COVID-19. Outcomes of interest included the incidence of cryptococcosis following the diagnosis of COVID-19 as well as the proportion of patients in each group who had underlying comorbidities, received immunomodulatory therapy, required ICU admission or mechanical ventilation (MV), or died. Propensity score matching was used to adjust for confounding. Among 212,479 hospitalised patients with COVID-19, 65 developed cryptococcosis. The incidence of cryptococcosis following COVID-19 was 0.022%. Patients with cryptococcosis were more likely to be male and have underlying comorbidities. Among cases, 32% were people with HIV. Patients with cryptococcosis were more likely to have received tocilizumab (p < .0001) or baricitinib (p < .0001), but not dexamethasone (p = .0840). ICU admission (38% vs 29%), MV (23% vs 11%), and mortality (36% vs 14%) were significantly higher among patients with cryptococcosis. Mortality remained elevated after adjusted propensity score matching. Cryptococcosis occurred most often in hospitalised patients with COVID-19 who had traditional risk factors, comparable to findings in patients without COVID-19. Cryptococcosis was associated with increased ICU admission, MV, and mortality.

“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.

An overview of COVID-19 related to fungal infections: what do we know after the first year of pandemic?

In 2019, severe acute respiratory syndrome caused by CoV-2 virus became a pandemic worldwide, being the fast spread of the disease due to the movement of infected people from one country to another, from one continent to another, or within the same country. Associated comorbidities are important factors that predispose to any fungal coinfections. Because of the importance of fungal infections in COVID-19 patients, the aim of this work was to collect data of the more encountered mycoses related to patients undergoing this disease. Aspergillosis was the first COVID-19-related fungal infection reported, being A. fumigatus the most frequent species for CAPA. Other fungal infections related include mainly candidiasis and mucormycosis, being Rhizopus spp. the more prevalent species found. Influenza-associated pulmonary aspergillosis is well documented; thus, similar complications are expected in severe forms of COVID-19 pneumonia. Therefore, in patients with COVID-19, it is important to take special attention to the surveillance and suspicion of fungal coinfections that might worsen the patient's prognosis.

COVID-19-associated pulmonary aspergillosis (CAPA): Risk factors and development of a predictive score for critically ill COVID-19 patients

BACKGROUND

COVID-19-associated pulmonary aspergillosis (CAPA) is a major complication of critically ill COVID-19 patients, with a high mortality rate and potentially preventable. Thus, identifying patients at high risk of CAPA would be of great interest. We intended to develop a clinical prediction score capable of stratifying patients according to the risk for CAPA at ICU admission.

METHODS

Single centre retrospective case-control study. A case was defined as a patient diagnosed with CAPA according to 2020 ECMM/ISHAM consensus criteria. 2 controls were selected for each case among critically ill COVID-19 patients.

RESULTS

28 CAPA patients and 56-matched controls were included. Factors associated with CAPA included old age (68 years vs. 62, p = .033), active smoking (17.9% vs. 1.8%, p = .014), chronic respiratory diseases (48.1% vs. 26.3%, p = .043), chronic renal failure (25.0% vs. 3.6%, p = .005), chronic corticosteroid treatment (28.6% vs. 1.8%, p < .001), tocilizumab therapy (92.9% vs. 66.1%, p = .008) and high APACHE II at ICU admission (median 13 vs. 10 points, p = .026). A score was created including these variables, which showed an area under the receiver operator curve of 0.854 (95% CI 0.77-0.92). A punctuation below 6 had a negative predictive value of 99.6%. A punctuation of 10 or higher had a positive predictive value of 27.9%.

CONCLUSION

We present a clinical prediction score that allowed to stratify critically ill COVID-19 patients according to the risk for developing CAPA. This CAPA score would allow to target preventive measures. Further evaluation of the score, as well as the utility of these targeted preventive measures, is needed.

Invasive Respiratory Fungal Infections in COVID-19 Critically Ill Patients

Patients with coronavirus disease 19 (COVID-19) admitted to the intensive care unit (ICU) often develop respiratory fungal infections. The most frequent diseases are the COVID-19 associated pulmonary aspergillosis (CAPA), COVID-19 associated pulmonary mucormycosis (CAPM) and the Pneumocystis jirovecii pneumonia (PCP), the latter mostly found in patients with both COVID-19 and underlying HIV infection. Furthermore, co-infections due to less common mold pathogens have been also described. Respiratory fungal infections in critically ill patients are promoted by multiple risk factors, including epithelial damage caused by COVID-19 infection, mechanical ventilation and immunosuppression, mainly induced by corticosteroids and immunomodulators. In COVID-19 patients, a correct discrimination between fungal colonization and infection is challenging, further hampered by sampling difficulties and by the low reliability of diagnostic approaches, frequently needing an integration of clinical, radiological and microbiological features. Several antifungal drugs are currently available, but the development of new molecules with reduced toxicity, less drug-interactions and potentially active on difficult to treat strains, is highly warranted. Finally, the role of prophylaxis in certain COVID-19 populations is still controversial and must be further investigated.

Tracheal Aspirate Galactomannan Testing in COVID-19-Associated Pulmonary Aspergillosis

Among critically ill patients, COVID-19-associated pulmonary aspergillosis (CAPA) is a challenging complication. The recommended diagnostic methods for this disease are bronchoalveolar lavage (BAL) culture and galactomannan (GM) testing, which were not widely available during the pandemic. There is scarce information regarding GM testing in other respiratory specimens. Our objective was to compare the agreement of GM between BAL and tracheal aspirate (TA) samples. We selected patients with COVID-19 and those with suspected CAPA who were admitted in the intensive care unit (ICU). GM was routinely done in BAL. We performed GM in TA samples and compared the results. The agreement was evaluated with Cohen's Kappa coefficient. GM was considered positive when an OD index ≥ 1 in BAL and ≥ 2 in TA were found. Probable CAPA was considered when the ECMM/ISHAM criteria were met. A descriptive analysis of clinical characteristics and mortality was made. We included 20 patients with suspected CAPA from 54 patients with critical COVID-19, of which 5 (9%) met the probable category. Aspergillus fumigatus was the most frequent isolate. We found moderate agreement between BAL and TA GM (Kappa = 0.47, p = 0.01, 95% CI.04-0.9), whereas TA GM had 75% sensitivity (95% CI 19.4-99.4%), 81.2% specificity (95% CI 54.4-95.9%), 50% positive predictive value (95% CI 23.8-76.3%),] and 92.8% negative predictive value (95% CI 70.1-98.6%), and 80% accuracy (95% CI 56.3-94.3%). Lastly, three (60%) patients with CAPA died during hospitalization compared to 40% (6/15) without CAPA (p = 0.4). In conclusion, a moderate agreement between TA GM and BAL was found. Therefore, TA testing may aid in ruling out CAPA due to high negative predictive value when bronchoscopies are unavailable.

Aspergillus-PCR in bronchoalveolar lavage diagnostic accuracy for invasive pulmonary aspergillosis in critically ill patients

BACKGROUND

Diagnosis of invasive pulmonary aspergillosis (IPA) in intensive care unit (ICU) patients is challenging and the role of Aspergillus-PCR in bronchoalveolar lavage (BAL) is unknown.

OBJECTIVES

This study evaluated diagnostic accuracy of Aspergillus-PCR in BAL in IPA in three different cohorts: ICU-admitted patients with COVID-19, ICU-admitted patients without COVID-19 and immunocompromised patients.

METHODS

All stored available BAL samples collected from three patient groups were tested with Aspergillus-PCR (AsperGenius®). IPA was diagnosed according to appropriate criteria for each patient group.

RESULTS

We included 111 BAL samples from 101 patients: 52 (51%) patients admitted to ICU for COVID-19, 24 (24%) admitted to ICU for other reasons and 25 (25%) immunocompromised. There were 31 cases of IPA (28%). Aspergillus-PCR sensitivity was 64% (95%CI 47-79), specificity 99% (95%CI 93-100). Aspergillus-PCR sensitivity was 40% (95%CI 19-64) in ICU COVID-19, 67% (95%CI 21-93) in non-COVID-19 ICU patients and 92% (95%CI 67-98) in the immunocompromised. The concordance between positive BAL-GM and BAL-PCR in patients with and without IPA was significantly lower in ICU patients (32%; 43% in COVID-19, 18% in non-COVID-19) than in the immunocompromised (92%), p<0.001.

CONCLUSIONS

Aspergillus-PCR in BAL improves the diagnostic accuracy of BAL-GM in ICU patients.

Defining COVID-19 associated pulmonary aspergillosis: systematic review and meta-analysis

Background

Pulmonary aspergillosis may complicate coronavirus disease 2019 (COVID-19) and contribute to excess mortality in intensive care unit (ICU) patients. The disease is poorly understood, in part due to discordant definitions across studies.

Objectives

We sought to review the prevalence, diagnosis, treatment, and outcomes of COVID-19–associated pulmonary aspergillosis (CAPA) and compare research definitions.

Data sources

PubMed, Embase, Web of Science, and MedRxiv were searched from inception to October 12, 2021.

Study eligibility criteria

ICU cohort studies and CAPA case series including ≥3 patients were included.

Participants

Adult patients in ICUs with COVID-19.

Interventions

Patients were reclassified according to four research definitions. We assessed risk of bias with an adaptation of the Joanna Briggs Institute cohort checklist tool for systematic reviews.

Methods

We calculated CAPA prevalence using the Freeman-Tukey random effects method. Correlations between definitions were assessed with Spearman's rank test. Associations between antifungals and outcome were assessed with random effects meta-analysis.

Results

Fifty-one studies were included. Among 3297 COVID-19 patients in ICU cohort studies, 313 were diagnosed with CAPA (prevalence 10%; 95% CI 8%–13%). Two hundred seventy-seven patients had patient-level data allowing reclassification. Definitions had limited correlation with one another (ρ = 0.268–0.447; p < 0.001), with the exception of Koehler and Verweij (ρ = 0.893; p < 0.001); 33.9% of patients reported to have CAPA did not fulfill any research definitions. Patients were diagnosed after a median of 8 days (interquartile range 5–14) in ICUs. Tracheobronchitis occurred in 3% of patients examined with bronchoscopy. The mortality rate was high (59.2%). Applying CAPA research definitions did not strengthen the association between mould-active antifungals and survival.

Conclusions

The reported prevalence of CAPA is significant but may be exaggerated by nonstandard definitions.

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.

A Visual and Comprehensive Review on COVID-19-Associated Pulmonary Aspergillosis (CAPA)

Coronavirus disease 19 (COVID-19)-associated pulmonary aspergillosis (CAPA) is a severe fungal infection complicating critically ill COVID-19 patients. Numerous retrospective and prospective studies have been performed to get a better grasp on this lethal co-infection. We performed a qualitative review and summarized data from 48 studies in which 7047 patients had been included, of whom 820 had CAPA. The pooled incidence of proven, probable or putative CAPA was 15.1% among 2953 ICU-admitted COVID-19 patients included in 18 prospective studies. Incidences showed great variability due to multiple factors such as discrepancies in the rate and depth of the fungal work-up. The pathophysiology and risk factors for CAPA are ill-defined, but therapy with corticosteroids and anti-interleukin-6 therapy potentially confer the biggest risk. Sampling for mycological work-up using bronchoscopy is the cornerstone for diagnosis, as imaging is often aspecific. CAPA is associated with an increased mortality, but we do not have conclusive data whether therapy contributes to an increased survival in these patients. We conclude our review with a comparison between influenza-associated pulmonary aspergillosis (IAPA) and CAPA.

Early Identification and Diagnostic Approach in Acute Respiratory Distress Syndrome (ARDS)

Acute respiratory distress syndrome (ARDS) is a life-threatening condition defined by the acute onset of severe hypoxemia with bilateral pulmonary infiltrates, in the absence of a predominant cardiac involvement. Whereas the current Berlin definition was proposed in 2012 and mainly focused on intubated patients under invasive mechanical ventilation, the recent COVID-19 pandemic has highlighted the need for a more comprehensive definition of ARDS including patients treated with noninvasive oxygenation strategies, especially high-flow nasal oxygen therapy, and fulfilling all other diagnostic criteria. Early identification of ARDS in patients breathing spontaneously may allow assessment of earlier initiation of pharmacological and non-pharmacological treatments. In the same way, accurate identification of the ARDS etiology is obviously of paramount importance for early initiation of adequate treatment. The precise underlying etiological diagnostic (bacterial, viral, fungal, immune, malignant, drug-induced, etc.) as well as the diagnostic approach have been understudied in the literature. To date, no clinical practice guidelines have recommended structured diagnostic work-up in ARDS patients. In addition to lung-protective ventilation with the aim of preventing worsening lung injury, specific treatment of the underlying cause has a central role to improve outcomes. In this review, we discuss early identification of ARDS in non-intubated patients breathing spontaneously and propose a structured diagnosis work-up.

Coronavirus Disease 2019-Associated Invasive Fungal Infection

Coronavirus disease 2019 (COVID-19) can become complicated by secondary invasive fungal infections (IFIs), stemming primarily from severe lung damage and immunologic deficits associated with the virus or immunomodulatory therapy. Other risk factors include poorly controlled diabetes, structural lung disease and/or other comorbidities, and fungal colonization. Opportunistic IFI following severe respiratory viral illness has been increasingly recognized, most notably with severe influenza. There have been many reports of fungal infections associated with COVID-19, initially predominated by pulmonary aspergillosis, but with recent emergence of mucormycosis, candidiasis, and endemic mycoses. These infections can be challenging to diagnose and are associated with poor outcomes. The reported incidence of IFI has varied, often related to heterogeneity in patient populations, surveillance protocols, and definitions used for classification of fungal infections. Herein, we review IFI complicating COVID-19 and address knowledge gaps related to epidemiology, diagnosis, and management of COVID-19-associated fungal infections.

Invasive Fungal Infections Complicating COVID-19: A Narrative Review

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

Comparing the clinical characteristics and outcomes of COVID-19-associate pulmonary aspergillosis (CAPA): a systematic review and meta-analysis

PURPOSE

Invasive pulmonary aspergillosis has been increasingly recognized in COVID-19 patients, termed COVID-19-associate pulmonary aspergillosis (CAPA). Our meta-analysis aims to assess the clinical characteristics and outcomes of patients diagnosed with CAPA compared to those without CAPA.

METHODS

We searched the Pubmed, Cochrane Library, SCOPUS, and Web of Science databases for studies published between January 1, 2020 and August 1, 2021, containing comparative data of patients diagnosed with CAPA and those without CAPA.

RESULTS

Eight cohort studies involving 729 critically ill COVID-19 patients with comparative data were included. CAPA patients were older (mean age 66.58 vs. 59.25 years; P = 0.007) and had underlying chronic obstructive pulmonary disease (COPD) (13.7 vs. 6.1%; OR 2.75; P = 0.05). No differences in gender, body mass index (BMI), and comorbidities of diabetes and cancer were observed. CAPA patients were more likely to receive long-term corticosteroid treatment (15.0 vs. 5.3%; OR 3.53; P = 0.03). CAPA patients had greater severity of illness based on sequential organ failure assessment (SOFA) score with a higher all-cause in-hospital mortality rate (42.6 vs. 26.5%; OR 3.39; P < 0.001) and earlier ICU admission from illness onset (mean 11.00 vs. 12.00 days; P = 0.003). ICU length of stay (LOS), invasive mechanical ventilation (IMV) duration, the requirement of inotropic support and renal replacement therapy were comparable between the two groups.

CONCLUSIONS

CAPA patients are typically older with underlying COPD and received long-term corticosteroid treatment. Furthermore, CAPA is associated with higher SOFA scores, mortality, and earlier onset of ICU admission from illness onset.

Taskforce report on the diagnosis and clinical management of COVID-19 associated pulmonary aspergillosis

Purpose

Invasive pulmonary aspergillosis (IPA) is increasingly reported in patients with severe coronavirus disease 2019 (COVID-19) admitted to the intensive care unit (ICU). Diagnosis and management of COVID-19 associated pulmonary aspergillosis (CAPA) are challenging and our aim was to develop practical guidance.

Methods

A group of 28 international experts reviewed current insights in the epidemiology, diagnosis and management of CAPA and developed recommendations using GRADE methodology.

Results

The prevalence of CAPA varied between 0 and 33%, which may be partly due to variable case definitions, but likely represents true variation. Bronchoscopy and bronchoalveolar lavage (BAL) remain the cornerstone of CAPA diagnosis, allowing for diagnosis of invasive Aspergillus tracheobronchitis and collection of the best validated specimen for Aspergillus diagnostics. Most patients diagnosed with CAPA lack traditional host factors, but pre-existing structural lung disease and immunomodulating therapy may predispose to CAPA risk. Computed tomography seems to be of limited value to rule CAPA in or out, and serum biomarkers are negative in 85% of patients. As the mortality of CAPA is around 50%, antifungal therapy is recommended for BAL positive patients, but the decision to treat depends on the patients’ clinical condition and the institutional incidence of CAPA. We recommend against routinely stopping concomitant corticosteroid or IL-6 blocking therapy in CAPA patients.

Conclusion

CAPA is a complex disease involving a continuum of respiratory colonization, tissue invasion and angioinvasive disease. Knowledge gaps including true epidemiology, optimal diagnostic work-up, management strategies and role of host-directed therapy require further study.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06449-4.

Incidence and mortality of COVID-19-associated pulmonary aspergillosis: A systematic review and meta-analysis

COVID-19-associated pulmonary aspergillosis (CAPA) has been reported worldwide. However, basic epidemiological characteristics have not been well established. In this systematic review and meta-analysis, we aimed to determine the incidence and mortality of CAPA in critically ill patients with COVID-19 to improve guidance on surveillance and prognostication. Observational studies reporting COVID-19-associated pulmonary aspergillosis were searched with PubMed and Embase databases, followed by an additional manual search in April 2021. We performed a one-group meta-analysis on the incidence and mortality of CAPA using a random-effect model. We identified 28 observational studies with a total of 3148 patients to be included in the meta-analysis. Among the 28 studies, 23 were conducted in Europe, two in Mexico and one each in China, Pakistan and the United States. Routine screening for secondary fungal infection was employed in 13 studies. The modified AspICU algorithm was utilised in 15 studies and was the most commonly used case definition and diagnostic algorithm for pulmonary aspergillosis. The incidence and mortality of CAPA in the ICU were estimated to be 10.2% (95% CI, 8.0-12.5; I²  = 82.0%) and 54.9% (95% CI, 45.6-64.2; I²  = 62.7%), respectively. In conclusion, our estimates may be utilised as a basis for surveillance of CAPA and prognostication in the ICU. Large, prospective cohort studies based on the new case definitions of CAPA are warranted to validate our estimates.