A screening study for COVID ‐19‐associated pulmonary aspergillosis in critically ill patients during the third wave of the pandemic

Severe mold fungal infections in critically ill patients with COVID-19

The SARS-CoV-2 pandemic put an unprecedented strain on modern societies and healthcare systems. A significantly higher incidence of invasive fungal co-infections was noted compared with the pre-COVID-19 era, adding new diagnostic and therapeutic challenges in the critical care setting. In the current narrative review, we focus on invasive mold infections caused by Aspergillus and Mucor species in critically ill COVID-19 patients. We discuss up-to-date information on the incidence, pathogenesis, diagnosis and treatment of these mold-COVID-19 co-infections, as well as recommendations on preventive and prophylactic interventions. Traditional risk factors were often not recognized in COVID-19-associated aspergillosis and mucormycosis, highlighting the role of other determinant risk factors. The associated patient outcomes were worse compared with COVID-19 patients without mold co-infection.

Utility of an in-house real-time PCR in whole blood samples as a minimally invasive method for early and accurate diagnosis of invasive mould infections

INTRODUCTION

Invasive mould infections (IMIs) are a leading cause of death in patients with compromised immune systems. Proven invasive mould infection requires detection of a fungus by histopathological analysis of a biopsied specimen, sterile culture, or fungal DNA amplification by PCR in tissue. However, the clinical performance of a PCR assay on blood samples taken from patients suspected of invasive mould disease has not been fully evaluated, particularly for the differential diagnosis of invasive aspergillosis (IA) and invasive Mucormycosis (IM).

OBJECTIVES

To assess the diagnostic utility of our previously validated in-house real-time PCR in blood samples for diagnosis of invasive aspergillosis and mucormycosis in patients with suspected invasive mould infection.

METHODS

All patients with suspected invasive mould infection were prospectively enrolled from May 2021 to July 2021. Conventional fungal diagnosis was performed using tissue and respiratory samples. In-house PCR was performed on blood samples and its diagnostic performance evaluated.

RESULTS

A total of 158 cases of suspected invasive mould infection were enrolled in the study. The sensitivity and specificity of in-house PCR performed on blood samples was found to be 92.5% and 81.4% respectively for diagnosis of probable IA, and 65% and 84.62% respectively for diagnosis of proven and probable IM. It was also able to detect 3 out of 5 cases of possible IM where no other microbiological evidence of IM was obtained.

CONCLUSIONS

This assay could be helpful in minimally invasive diagnosis of IMIs for patients in whom invasive sampling is not feasible, especially as a preliminary or screening test. It can help in early diagnosis, anticipating conventional laboratory confirmation by days or weeks. Possible correlation between fungal load and mortality can help in initiating aggressive treatment for patients with high initial fungal load.

Incidence and Mortality of COVID-19-Associated Invasive Fungal Infections Among Critically Ill Intubated Patients: A Multicenter Retrospective Cohort Analysis

Background

An association between coronavirus disease 2019 (COVID-19)-associated invasive fungal infections (CAIFIs) and high mortality among intubated patients has been suggested in previous research. However, some of the current evidence was derived from small case series and multicenter studies conducted during different waves of the COVID-19 pandemic. We examined the incidence of CAIFIs and their associated mortality using a large, multicenter COVID-19 database built throughout the pandemic.

Methods

We conducted a retrospective analysis of the National COVID Cohort Collaborative (N3C) database collected from 76 medical centers in the United States between January 2020 and August 2022. Patients were 18 years or older and intubated after severe acute respiratory syndrome coronavirus 2 infection. The primary outcomes were incidence and all-cause mortality at 90 days. To assess all-cause mortality, we fitted Cox proportional hazard models after adjusting for confounders via inverse probability weighting.

Results

Out of the 4 916 229 patients with COVID-19 diagnosed during the study period, 68 383 (1.4%) met our cohort definition. The overall incidence of CAIFI was 2.80% (n = 1934/68 383). Aspergillus (48.2%; n = 933/1934) and Candida (41.0%; n = 793/1934) were the most common causative organisms. The incidence of CAIFIs associated with Aspergillus among patients who underwent BAL was 6.2% (n = 83/1328). Following inverse probability weighting, CAIFIs caused by Aspergillus (hazard ratio [HR], 2.0; 95% CI, 1.8-2.2) and Candida (HR, 1.7; 95% CI, 1.5-1.9) were associated with increased all-cause mortality. Systemic antifungals reduced mortality in 17% of patients with CAIFI with Aspergillus and 24% of patients with CAIFI with Candida.

Conclusions

The incidence of CAIFI was modest but associated with higher 90-day all-cause mortality among intubated patients. Systemic antifungals modified mortality.

Age difference of patients with and without invasive aspergillosis: a systematic review and meta-analysis

BACKGROUND

Invasive Aspergillosis (IA) is a life-threatening fungal disease with significant mortality rates. Timely diagnosis and treatment greatly enhance patient outcomes. This study aimed to explore the association between patient age and the development of IA, as well as the potential implications for risk stratification strategies.

METHODS

We searched National Center for Biotechnology Information (NCBI) databases for publications until October 2023 containing age characteristics of patients with and without IA. A random-effects model with the application of inverse-variance weighting was used to pool reported estimates from each study, and meta-regression and subgroup analyses were utilized to assess sources of heterogeneity.

RESULTS

A systematic review was conducted, resulting in the inclusion of 55 retrospective observational studies with a total of 13,983 patients. Meta-analysis revealed that, on average, patients with IA were approximately two and a half years older (95% Confidence Interval [CI] 1.84-3.31 years; I2 = 26.1%) than those without the disease (p < 0.0001). No significant moderators could explain the observed heterogeneity in age difference. However, subgroup analysis revealed that age differences were more pronounced within particular patient groups compared to others. For example, patients with and without IA who had primary severe lung infections exhibited a greater difference in mean age than other patient cohorts.

CONCLUSIONS

Further research, such as individual patient data meta-analysis, is necessary to better understand the potential relationship between increasing age and the likelihood of IA. Improved risk stratification strategies based on patient age could potentially enhance the early detection and treatment of IA, ultimately improving patient outcomes.

Fungal infections in patients after recovering from COVID-19: a systematic review

Background and aims

The presence of fungal infections has been described in patients after recovering from COVID-19. This study aims to conduct a systematic review of studies that reported fungal infections (Mucor spp., Pneumocystis jirovecii, or Aspergillus spp.) in adults after recovering from COVID-19.

Methods

We performed a systematic review through PubMed, Web of Science, OVID-Medline, Embase, and Scopus. The study selection process was performed independently and by at least two authors. We performed a risk of bias assessment using the Newcastle-Ottawa Scale for cohort and case-control studies, and the Joanna Briggs Institute's Checklists for Case Series and Case Reports.

Results

The systematic search found 33 studies meeting all inclusion criteria. There was a total population of 774 participants, ranging from 21 to 87 years. From them, 746 developed a fungal infection. In 19 studies, Mucor spp. was reported as the main mycosis. In 10 studies, P. jirovecii was reported as the main mycosis. In seven studies, Aspergillus spp. was reported as the main mycosis. Regarding the quality assessment, 12 studies were classified as low risk of bias and the remaining studies as high risk of bias.

Conclusion

Patients' clinical presentation and prognosis after recovering from COVID-19 with fungal infection differ from those reported patients with acute COVID-19 infection and those without COVID-19 infection.

COVID-19-associated pulmonary aspergillosis (CAPA): identification of Aspergillus species and determination of antifungal susceptibility profiles

Among the co-infectious agents in COVID-19 patients, Aspergillus species cause invasive pulmonary aspergillosis (IPA). IPA is difficult to diagnose and is associated with high morbidity and mortality. This study is aimed at identifying Aspergillus spp. from sputum and tracheal aspirate (TA) samples of COVID-19 patients and at determining their antifungal susceptibility profiles. A total of 50 patients with COVID-19 hospitalized in their intensive care units (ICU) were included in the study. Identification of Aspergillus isolates was performed by phenotypic and molecular methods. ECMM/ISHAM consensus criteria were used for IPA case definitions. The antifungal susceptibility profiles of isolates were determined by the microdilution method. Aspergillus spp. was detected in 35 (70%) of the clinical samples. Among the Aspergillus spp., 20 (57.1%) A. fumigatus, six (17.1%) A. flavus, four (11.4%) A. niger, three (8.6%) A. terreus, and two (5.7%) A. welwitschiae were identified. In general, Aspergillus isolates were susceptible to the tested antifungal agents. In the study, nine patients were diagnosed with possible IPA, 11 patients were diagnosed with probable IPA, and 15 patients were diagnosed with Aspergillus colonization according to the used algorithms. Serum galactomannan antigen positivity was found in 11 of the patients diagnosed with IPA. Our results provide data on the incidence of IPA, identification of Aspergillus spp., and its susceptibility profiles in critically ill COVID-19 patients. Prospective studies are needed for a faster diagnosis or antifungal prophylaxis to manage the poor prognosis of IPA and reduce the risk of mortality.

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.

Diagnostic performance and longitudinal analysis of fungal biomarkers in COVID-19 associated pulmonary aspergillosis

Objectives

Galactomannan lateral flow assay (GM-LFA) is a reliable test for COVID-19 associated pulmonary aspergillosis (CAPA) diagnosis. We aimed to assess the diagnostic performance of GM-LFA with different case definitions, the association between the longitudinal measurements of serum GM-ELISA, GM-LFA, and the risk of death.

Methods

Serum and nondirected bronchial lavage (NBL) samples were periodically collected. The sensitivity and specificity analysis for GM-LFA was done in different time periods. Longitudinal analysis was done with the joint model framework.

Results

A total of 207 patients were evaluated. On the day of CAPA diagnosis, serum GM-LFA had a sensitivity of 42 % (95 % CI: 23-63) and specificity of 82 % (95 % CI: 78-84), while NBL GM-LFA had a sensitivity of 73 % (95 % CI: 45-92), specificity of 85 % (95 % CI: 76-91) for CAPA. Sensitivity decreased through the following days in both samples. Univariate joint model analysis showed that increasing GM-LFA and GM-ELISA levels were associated with increased mortality, and that effect remained same with serum GM-ELISA in multivariate joint model analysis.

Conclusion

GM-LFA, particularly in NBL samples, seems to be a reliable method for CAPA diagnosis. For detecting patients with higher risk of mortality, longitudinal measurement of serum GM-ELISA can be useful.

COVID-19-associated pulmonary aspergillosis in patients with severe SARS-CoV-2 infection: A single-center observational study from Greece

INTRODUCTION

COVID-19-associated pulmonary aspergillosis (CAPA) is a serious complication affecting patients with severe SARS-CoV-2 infection, and is associated with increased mortality.

OBJECTIVE

The objective of this study was to investigate potential risk factors, and to estimate the incidence and mortality in patients diagnosed with CAPA.

METHODS

A single-center retrospective observational study was conducted on patients admitted to the intensive care unit (ICU) with severe COVID-19 from October 2020 to May 2022. Patients with deterioration of their clinical status were evaluated with serum galactomannan (GM) for probable CAPA. Baseline demographic patient characteristics, vaccination status, and time period during which each patient was infected with SARS-CoV-2 were obtained, and risk stratification according to underlying comorbidities was performed in an effort to assess various risk factors for CAPA. The incidence of CAPA in the entire cohort was measured, and mortality rates in the CAPA and non-CAPA groups were calculated and compared.

RESULTS

Of 488 patients admitted to the ICU, 95 (19.4%) had deterioration of their clinical status, which prompted testing with serum GM. Positive serum testing was observed in 39/95 patients, with an overall CAPA incidence in the entire study cohort reaching 7.9% (39/488). The mortality rate was 75% (42/56) in the non-CAPA group that was tested for serum GM, and 87.2% (34/39) in the CAPA group (P = 0.041). Multivariable Cox regression hazard models were tested for 28- and 90-day survival from ICU admission. An invasive pulmonary aspergillosis (IPA) risk-stratified cox regression model corrected for the SARS-CoV-2 variant of the patient identified the diagnosis of probable CAPA and elevated procalcitonin (PCT) levels measured at least 10 days after ICU admission, as significantly associated with death in the IPA-risk subgroup only, with hazard ratio (HR): 3.687 (95% confidence interval [CI], 1.030-13.199, P = 0.045) for the diagnosis of probable CAPA, and HR: 1.022 (95% CI, 1.003-1.042, P = 0.026) for every 1 ng/mL rise in PCT.

CONCLUSIONS

Patients in the IPA-risk subgroup that were diagnosed with CAPA had a lower 90-day survival when compared to patients in the same group without a CAPA diagnosis.

Mortality in ICU Patients with COVID-19-Associated Pulmonary Aspergillosis

A review of 38 studies involving 1437 COVID-19 patients admitted to intensive care units (ICUs) with pulmonary aspergillosis (CAPA) was conducted to investigate whether mortality has improved since the pandemic's onset. The study found that the median ICU mortality was 56.8%, ranging from 30% to 91.8%. These rates were higher for patients admitted during 2020-2021 (61.4%) compared to 2020 (52.3%), and prospective studies found higher ICU mortality (64.7%) than retrospective ones (56.4%). The studies were conducted in various countries and used different criteria to define CAPA. The percentage of patients who received antifungal therapy varied across studies. These results indicate that the mortality rate among CAPA patients is a growing concern, mainly since there has been an overall reduction in mortality among COVID-19 patients. Urgent action is needed to improve prevention and management strategies for CAPA, and additional research is needed to identify optimal treatment strategies to reduce mortality rates among these patients. This study serves as a call to action for healthcare professionals and policymakers to prioritize CAPA, a serious and potentially life-threatening complication of COVID-19.

Active screening of COVID-19-associated pulmonary aspergillosis with serum beta-glucan and endotracheal aspirates galactomannan and fungal culture

BACKGROUND

Since February 2021 active screening of COVID-19-associated pulmonary aspergillosis (CAPA) has been implemented in our institution.

OBJECTIVES

To evaluate CAPA incidence in our centre and evaluate performance of our screening protocol.

METHODS

We screened once per week, collecting endotracheal aspirates for fungal culture and galactomannan (GM) and serum for 1,3-ß-D-glucan (BG). In case of positivity (GM more than 4.5, platelia assay, and/or BG >7 pg/ml, wako and/or positive fungal culture), second-level investigations were performed to pursue CAPA diagnosis according to ECMM/ISHAM criteria: bronchoalveolar lavage (BAL) fungal culture and GM, chest computed tomography (CT), serum GM.

RESULTS

A total of 102 patients were screened (median age 64 years, range 39-79; 28 (27.4%) females). Twenty-two patients were diagnosed with CAPA (21%). 12 patients were positive for serum BG, 17 patients were positive for endotracheal aspirates GM and 27 patients were positive for endotracheal aspirates fungal culture. Thirty-two BALs were performed, and 26 patients underwent CT chest. Following the second level investigations 61% of the patients with positive screening tests were diagnosed with CAPA. Serum BG above 20 pg/ml or positive serum GM were always associated with typical CT chest signs of aspergillosis. Compared with 1 single positive test, having 2 positive screening test was significantly more associated with CAPA diagnosis (p = .0004).

CONCLUSIONS

Active CAPA screening with serum 1,3-ß-D-glucan and endotracheal aspirates galactomannan and fungal cultures and consequent second level investigations led to high number of CAPA diagnosis. Combining more positive fungal biomarkers was more predictive of CAPA diagnosis.

Invasive Pulmonary Aspergillosis in Patients with and without SARS-CoV-2 Infection

The recent European Confederation of Medical Mycology (ECMM) and the International Society for Human and Animal Mycology (ISHAM) 2020 consensus classification proposes criteria to define coronavirus 2019 (COVID-19)-associated invasive pulmonary aspergillosis (CAPA), including mycological evidence obtained via non-bronchoscopic lavage. Given the low specificity of radiological findings in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, this criterion makes it difficult to differentiate between invasive pulmonary aspergillosis (IPA) and colonization. This unicenter and retrospective study includes 240 patients with isolates of any Aspergillus species in any respiratory samples during a 20-month study (140 IPA and 100 colonization). Mortality was high in the IPA and colonization groups (37.1% and 34.0%, respectively; p = 0.61), especially in patients with SARS-CoV-2 infection, where mortality was higher in colonized patients (40.7% vs. 66.6.%; p: 0.021). Multivariate analysis confirmed the following variables to be independently associated with increased mortality: age > 65 years, acute or chronic renal failure at diagnosis, thrombocytopenia (<100,000 platelets/µL) at admission, inotrope requirement, and SARS-CoV-2 infection, but not the presence of IPA. This series shows that the isolation of Aspergillus spp. in respiratory samples, whether associated with disease criteria or not, is associated with high mortality, especially in patients with SARS-CoV-2 infection, and suggests an early initiation of treatment given its high mortality rate.

Comparison of risk factors and outcome of patients with and without COVID ‐19 associated pulmonary aspergillosis from Pakistan: A case‐control study

Background

Early identification of COVID‐19‐associated pulmonary aspergillosis (CAPA) is particularly challenging in low‐ middle‐income countries where diagnostic capabilities are limited, and risk factors for CAPA have not been identified. It is also essential to recognise CAPA patients who are likely to have a poorer outcome to decide on aggressive management approaches. Therefore, this study aimed to identify risk factors and outcomes for CAPA among admitted moderate to critical COVID‐19 patients at our centre in Pakistan.

Methods

An unmatched case–control study with ratio of 1:2 was conducted on hospitalised adult patients with COVID‐19 from March 2020–July 2021. Cases were defined according to European Confederation of Medical Mycology and the International Society for Human and Animal Mycology consensus criteria. Controls were defined as patients hospitalised with moderate, severe or critical COVID‐19 without CAPA.

Results

A total of 100 CAPA cases (27 probable CAPA; 73 possible CAPA) were compared with 237 controls. Critical disease at presentation (aOR 5.04; 95% CI 2.18–11.63), age ≥ 60 years (aOR 2.00; 95% CI 1.20–3.35) and underlying co‐morbid of chronic kidney disease (CKD) (aOR 3.78; 95% CI 1.57–9.08) were identified as risk factors for CAPA. Patients with CAPA had a significantly greater proportion of complications and longer length of hospital stay (p‐value < .001). Mortality was higher in patients with CAPA (48%) as compared to those without CAPA (13.5%) [OR = 6.36(95% CI 3.6–11)].

Conclusions

CAPA was significantly associated with advanced age, CKD and critical illness at presentation, along with a greater frequency of complications and higher mortality.

Overview of COVID-19-Associated Invasive Fungal Infection

Purpose of Review

Invasive fungal infections are a complication of COVID-19 disease. This article reviews literature characterizing invasive fungal infections associated with COVID-19.

Recent Findings

Multiple invasive fungal infections including aspergillosis, candidiasis, pneumocystosis, other non-Aspergillus molds, and endemic fungi have been reported in patients with COVID-19. Risk factors for COVID-19-associated fungal disease include underlying lung disease, diabetes, steroid or immunomodulator use, leukopenia, and malignancy. COVID-19-associated pulmonary aspergillosis (CAPA) and COVID-19-associated mucormycosis (CAM) are the most common fungal infections described. However, there is variability in the reported incidences related to use of differing diagnostic algorithms.

Summary

Fungal pathogens are important cause of infection in patients with COVID-19, and the diagnostic strategies continue to evolve. Mortality in these patients is increased, and providers should operate with a high index of suspicion. Further studies will be required to elucidate the associations and pathogenesis of these diseases and best management and prevention strategies.