Influenza-Associated Aspergillosis: Nationwide Trends, Predictors and Outcomes From 2005 to 2014

Comparison of influenza- and COVID-19-associated pulmonary aspergillosis in China

PURPOSE

We conducted a monocentric retrospective study using the latest definitions to compare the demographic, clinical, and biological characteristics of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA).

METHODS

The study retrospectively enrolled 180 patients, including 70 influenza/IPA patients (with positive influenza A/B and Aspergillus) and 110 COVID-19/IPA patients (with positive SARS-CoV-2 and Aspergillus). Among them, 42 (60%) and 30 (27.3%) patients fulfilled the definitions of IAPA and CAPA, respectively.

RESULTS

The CAPA patients had significantly higher in-hospital mortality (13/31, 41.9%) than IAPA patients (8/42, 19%) with a P-value of 0.033. Kaplan-Meier survival curve also showed significantly higher 30-day mortality for CAPA patients (P = 0.025). Additionally, the CAPA patients were older, though insignificantly, than IAPA patients (70 (60-80) vs. 62 (52-72), P = 0.075). A lower percentage of chronic pulmonary disease (12.9 vs. 40.5%, P = 0.01) but higher corticosteroids use 7 days before and after ICU admission (22.6% vs. 0%, P = 0.002) were found in CAPA patients. Notably, there were no significant differences in the percentage of ICU admission or ICU mortality between the two groups. In addition, the time from observation to Aspergillus diagnosis was significantly longer in CAPA patients than in IAPA patients (7 (2-13) vs. 0 (0-4.5), P = 0.048).

CONCLUSION

Patients infected with SARS-CoV-2 and Aspergillus during the concentrated outbreak of COVID-19 in China had generally higher in-hospital mortality but a lower percentage of chronic pulmonary disease than those infected with influenza and Aspergillus. For influenza-infected patients who require hospitalization, close attention should be paid to the risk of invasive aspergillosis upfront.

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.

Incidence and inhospital outcomes of coronavirus disease 2019-associated pulmonary aspergillosis in the United States

OBJECTIVE

The aim of this study was to estimate the predictors, associations, and outcomes of COVID-19-associated pulmonary disease (CAPA) in the United States.

STUDY DESIGN AND METHODS

This retrospective cohort study was performed by using the National Inpatient Sample Database 2020 to identify coronavirus disease 2019 (COVID-19) and CAPA hospitalizations. Baseline variables and outcomes were compared between COVID-19 hospitalizations without aspergillosis and those with aspergillosis. These variables were then used to perform an adjusted analysis for obtaining predictors and factors associated with CAPA and its inhospital mortality.

RESULTS

Of the 1,020,880 hospitalizations identified with the principal diagnosis of COVID-19, CAPA was identified in 1510 (0.1%) hospitalizations. The CAPA cohort consisted of a higher proportion of males (58%) as well as racial and ethnic minorities (Hispanics, Blacks, and others [including Asian or Pacific islanders, native Americans]). Inhospital mortality was significantly higher (47.35% vs. 10.87%, P < 0.001), the average length of stay was longer (27.61 vs. 7.29 days, P < 0.001), and the mean cost per hospitalization was higher ($121,560 vs. $18,423, P < 0.001) in the CAPA group compared to COVID-19 without aspergillosis. History of solid organ transplant, chronic obstructive pulmonary disease, and venous thromboembolism were associated with higher odds of CAPA among other factors. The use of invasive mechanical ventilation (adjusted odds ratio [aOR] 6.24, P < 0.001), acute kidney injury (aOR 2.02, P = 0.028), and septic shock (aOR 2.07, P = 0.018) were associated with higher inhospital mortality in the CAPA cohort.

CONCLUSION

While CAPA is an infrequent complication during hospitalizations for COVID-19, it significantly increases all-cause mortality, prolongs hospital stays, and leads to higher hospital expenses compared to COVID-19 cases without aspergillosis.

The Clinical Significance of Aspergillus Detected in Lower-Respiratory-Tract Samples of Critically Ill COVID-19-Positive Patients

Objective: Critically ill patients with acute respiratory distress syndrome (ARDS) due to viral infection are at risk for secondary complications, including invasive aspergillosis. Our study aimed to characterize the clinical significance and outcome of Aspergillus species isolated from lower-respiratory-tract samples of critically ill OVID-19 patients at a single center. Design: We conducted a retrospective cohort study to evaluate the characteristics of patients with COVID-19 and aspergillus isolated from the lower respiratory tract and to identify predictors of outcomes in this population. Setting: The setting was a single-center hospital system within the metropolitan Detroit region. Results: The prevalence of Aspergillus isolated in hospitalized COVID-19 patients was 1.18% (30/2461 patients), and it was 4.6% in critically ill ICU patients with COVID-19. Probable COVID-19-associated invasive pulmonary aspergillosis (CAPA) was found in 21 critically ill patients, and 9 cases were classified as colonization. The in-hospital mortality of critically ill patients with CAPA and those with aspergillus colonization were high but not significantly different (76% vs. 67%, p = 1.00). Furthermore, the in-hospital mortality for ICU patients with or without Aspergillus isolated was not significantly different 73.3% vs. 64.5%, respectively (OR 1.53, CI 0.64-4.06, p = 0.43). In patients in whom Aspergillus was isolated, antifungal therapy (p = 0.035, OR 12.3, CI 1.74-252); vasopressors (0.016, OR 10.6, CI 1.75-81.8); and a higher mSOFA score (p = 0.043, OR 1.29 CI 1.03-1.72) were associated with a worse outcome. In a multivariable model adjusting for other significant variables, FiO2 was the only variable associated with in-hospital mortality in patients in whom Aspergillus was isolated (OR 1.07, 95% CI 1.01-1.27). Conclusions: The isolation of Aspergillus from lower-respiratory-tract samples of critically ill patients with COVID-19 is associated with high mortality. It is important to have a low threshold for superimposed infections such as CAPA in critically ill patients with COVID-19.

Early Detection of Aspergillus Species in Lower Respiratory Tract is Associated with Higher Mortality in Viral Community-Acquired Pneumonia: A Multicenter Prospective Cohort Study in China

PURPOSE

Community-acquired pneumonia (CAP) is a leading cause of adult mortality worldwide and poses a significant global burden. Previous studies have indicated a tendency for viral pneumonia, particularly severe influenza virus pneumonia, to be complicated by Aspergillus superinfection. However, the clinical features and prognostic implications of Aspergillus detection in early-onset viral CAP remain unclear.

METHODS

We conducted a prospective multicenter observational cohort study in China involving CAP patients. Adult patients with CAP from six hospitals were enrolled between January 2017 and October 2018. Within 72 h of admission, lower respiratory tract specimens, including sputum and alveolar lavage fluid, were collected. Comprehensive pathogenic testing, utilizing molecular biology techniques, was performed on the collected specimens, encompassing bacteria, atypical pathogens, viruses, and fungi. Patient clinical data were collected through a unified electronic medical record website system.

RESULTS

A total of 382 adult CAP patients were included in the study. The viral detection rate was 38% (145/382), with Aspergillus identified in 11.0% (16/145) of viral CAP cases. Mortality among Aspergillus-positive patients was significantly higher (25%, 4/16) compared to Aspergillus-negative patients (5.4%, 7/129) in viral CAP (P = 0.021). Multivariable logistic regression models demonstrated that the presence of Aspergillus at admission might increase the mortality risk in viral CAP [OR (95%CI) = 7.34 (0.92-58.65), P = 0.06]. Furthermore, Aspergillus-positive patients exhibited a significantly lower lymphocyte count than Aspergillus-negative patients (P = 0.047).

CONCLUSION

Positive detection of Aspergillus in lower respiratory tract specimens might be associated with higher mortality in early-onset viral CAP.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03093220. Registered retrospectively on 28 March 2017.

Clinical Uses of Inhaled Antifungals for Invasive Pulmonary Fungal Disease: Promises and Challenges

The role of inhaled antifungals for prophylaxis and treatment of invasive fungal pneumonias remains undefined. Herein we summarize recent clinically relevant literature in high-risk groups such as neutropenic hematology patients, including those undergoing stem cell transplant, lung and other solid transplant recipients, and those with sequential mold lung infections secondary to viral pneumonias. Although there are several limitations of the available data, inhaled liposomal amphotericin B administered 12.5 mg twice weekly could be an alternative method of prophylaxis in neutropenic populations at high risk for invasive fungal pneumonia where systemic triazoles are not tolerated. In addition, inhaled amphotericin B has been commonly used as prophylaxis, pre-emptive, or targeted therapy for lung transplant recipients but is considered as a secondary alternative for other solid organ transplant recipients. Inhaled amphotericin B seems promising as prophylaxis in fungal pneumonias secondary to viral pneumonias, influenza, and SARS CoV-2. Data remain limited for inhaled amphotericin for adjunct treatment, but the utility is feasible.

Virus-associated fungal infections and lost immune resistance

Invasive fungal infections are an increasing threat to human health. Of recent concern is the emergence of influenza- or SARS-CoV-2-virus-associated invasive fungal infections. Understanding acquired susceptibilities to fungi requires consideration of the collective and newly explored roles of adaptive, innate, and natural immunity. Neutrophils are known to provide host resistance, but new concepts are emerging that implicate innate antibodies, the actions of specialized B1 B cell subsets, and B cell-neutrophil crosstalk in mediating antifungal host resistance. Based on emerging evidence, we propose that virus infections impact on neutrophil and innate B cell resistance against fungi, leading to invasive infections. These concepts provide novel approaches to developing candidate therapeutics with the aim of restoring natural and humoral immunity and boosting neutrophil resistance against fungi.

A B1a-natural IgG-neutrophil axis is impaired in viral- and steroid-associated aspergillosis

The lung naturally resists Aspergillus fumigatus (Af) in healthy individuals, but multiple conditions can disrupt this resistance, leading to lethal invasive infections. Core processes of natural resistance and its breakdown are undefined. We investigated three distinct conditions predisposing to lethal aspergillosis-severe SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection, influenza A viral pneumonia, and systemic corticosteroid use-in human patients and murine models. We found a conserved and essential coupling of innate B1a lymphocytes, Af-binding natural immunoglobulin G antibodies, and lung neutrophils. Failure of this axis concealed Af from neutrophils, allowing rapid fungal invasion and disease. Reconstituting the axis with immunoglobulin therapy reestablished resistance, thus representing a realistic pathway to repurpose currently available therapies. Together, we report a vital host resistance pathway that is responsible for protecting against life-threatening aspergillosis in the context of distinct susceptibilities.

Polymicrobial Infections in the Immunocompromised Host: The COVID-19 Realm and Beyond

Immunosuppression changes both susceptibility to and presentation of infection. Infection with one pathogen can also alter host response to a different, unrelated pathogen. These interactions have been seen across multiple infection domains where bacteria, viruses or fungi act synergistically with a deleterious impact on the host. This phenomenon has been well described with bacterial and fungal infections complicating influenza and is of particular interest in the context of the COVID-19 pandemic. Modulation of the immune system is a crucial part of successful solid organ and hematopoietic stem cell transplantation. Herein, we present three cases of polymicrobial infection in transplant recipients. These case examples highlight complex host–pathogen interactions and the resultant clinical syndromes.

COVID-19-Associated Pulmonary Mucormycosis

COVID-19-associated mucormycosis (CAM) emerged as an epidemic in certain parts of the world amidst the global COVID-19 pandemic. While rhino–orbital mucormycosis was well reported during the pandemic, in the absence of routine diagnostic facilities including lower airway sampling, pulmonary mucormycosis was probably under-recognized. In this review, we have focused on the epidemiology and management of COVID-19-associated pulmonary mucormycosis (CAPM). CAPM is a deadly disease and mortality can be as high as 80% in the absence of early clinical suspicion and treatment. While histopathological examination of tissue for angio-invasion and cultures have remained gold standard for diagnosis, there is an increasing interest in molecular and serological methods to facilitate diagnosis in critically ill patients and often, immune-suppressed hosts who cannot readily undergo invasive sampling. Combined medical and surgical treatment offers more promise than standalone medical therapy. Maintaining adequate glycemic control and prudent use of steroids which can be a double-edged sword in COVID-19 patients are the key preventative measures. We would like to emphasize the urgent need for the development and validation of reliable biomarkers and molecular diagnostics to facilitate early diagnosis.

Monoclonal Antibodies and Invasive Aspergillosis: Diagnostic and Therapeutic Perspectives

Invasive aspergillosis (IA) is a life-threatening fungal disease that causes high morbidity and mortality in immunosuppressed patients. Early and accurate diagnosis and treatment of IA remain challenging. Given the broad range of non-specific clinical symptoms and the shortcomings of current diagnostic techniques, most patients are either diagnosed as “possible” or “probable” cases but not “proven”. Moreover, because of the lack of sensitive and specific tests, many high-risk patients receive an empirical therapy or a prolonged treatment of high-priced antifungal agents, leading to unnecessary adverse effects and a high risk of drug resistance. More precise diagnostic techniques alongside a targeted antifungal treatment are fundamental requirements for reducing the morbidity and mortality of IA. Monoclonal antibodies (mAbs) with high specificity in targeting the corresponding antigen(s) may have the potential to improve diagnostic tests and form the basis for novel IA treatments. This review summarizes the up-to-date application of mAb-based approaches in assisting IA diagnosis and therapy.

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

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

SARS-CoV-2 Associated Immune Dysregulation and COVID-Associated Pulmonary Aspergilliosis (CAPA): A Cautionary Tale

As the global SARS-CoV-2 pandemic continues to plague healthcare systems, it has become clear that opportunistic pathogens cause a considerable proportion of SARS-CoV-2-associated mortality and morbidity cases. Of these, Covid-Associated Pulmonary Aspergilliosis (CAPA) is a major concern with evidence that it occurs in the absence of traditional risk factors such as neutropenia and is diagnostically challenging for the attending physician. In this review, we focus on the immunopathology of SARS-CoV-2 and how this potentiates CAPA through dysregulation of local and systemic immunity as well as the unintended consequences of approved COVID treatments including corticosteroids and IL-6 inhibitors. Finally, we will consider how knowledge of the above may aid in the diagnosis of CAPA using current diagnostics and what treatment should be instituted in probable and confirmed cases.

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

BACKGROUND

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

METHODS

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

RESULTS

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

INTERPRETATION

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

Clinical Characteristics and Outcomes of Influenza-Associated Pulmonary Aspergillosis Among Critically Ill Patients: A Systematic Review and Meta-Analysis

BACKGROUND

Invasive pulmonary aspergillosis is increasingly identified as a complication of influenza infection, termed influenza-associated pulmonary aspergillosis (IAPA).

AIMS

Assess the morbidity and mortality of critically ill influenza patients with and without IAPA.

METHODS

We searched the Pubmed, Cochrane Library, Scopus, and Embase databases for studies containing comparative data of critically ill influenza patients with IAPA. Primary outcomes were all-cause in-hospital and ICU mortality. The secondary outcomes were clinical characteristics, invasive mechanical ventilation (IMV) duration, ICU and hospital length of stay (LOS), requirement of vasopressor, renal replacement therapy (RRT), and extracorporeal membrane oxygenation (ECMO).

FINDINGS

IAPA incidence was 28.8% in 853 critically ill influenza patients, with an overall mortality rate of 33.4%. No difference in age and comorbidities were observed. IAPA patients were predominantly male and received chronic corticosteroids. In-hospital (49.2% vs. 27.0%; P= 0.002) and ICU (46.8% vs. 20.8%; P< 0.001) mortality rates were higher among IAPA patients than non-IAPA patients. Greater proportion of IAPA patients required IMV and prolonged IMV duration (mean 17.3 vs. 10.5 days; P< 0.001), ICU (mean 26.8 vs. 12.8 days; P= 0.001) and hospital LOS (mean 38.7 vs. 27.0 days; P= 0.003). IAPA patients had greater disease severity requiring a significant amount of vasopressor (76.4% vs. 57.9%; P< 0.001), RRT (45.7% vs. 19.1%; P< 0.001), and ECMO (25.9% vs. 12.8%; P= 0.004) support than non-IAPA patients.

CONCLUSIONS

IAPA diagnosis in critically ill patients is associated with greater morbidity and mortality. Early recognition and more research are needed to determine better diagnostic and treatment strategies.

Aspergillosis: Epidemiology, Diagnosis, and Treatment

The spectrum of disease produced by Aspergillus species ranges from allergic syndromes to chronic pulmonary conditions and invasive infections. Invasive aspergillosis is a major cause of morbidity and mortality in immunocompromised patients. Risk factors continue to evolve and include newer biological agents that target the immune system and postinfluenza infection; and it has been observed following COVID-19 infection. Diagnosis remains a challenge but non-culture-based methods are available. Antifungal resistance has emerged. Voriconazole remains the treatment of choice but isavuconazole and posaconazole have similar efficacy with less toxicity. Combination therapy is used with extensive infection and in severe immunosuppression.

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

Invasive pulmonary aspergillosis (IPA) is increasingly recognized as a life-threatening superinfection of severe respiratory viral infections, such as influenza. The pandemic of Coronavirus Disease 2019 (COVID-19) due to emerging SARS-CoV-2 rose concern about the eventuality of IPA complicating COVID-19 in intensive care unit mechanically-ventilated patients. While the association between severe influenza and IPA has been demonstrated, it remains unclear whether SARS-CoV-2 infection represents a specific risk factor for IPA. A variable incidence of such complication has been previously reported, which can be partly attributed to differences in diagnostic strategy and IPA definitions, and possibly local environmental/epidemiological factors. In this article, we discuss the similarities and differences between influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA). Compared to IAPA, the majority of CAPA cases have been classified as putative rather than proven/probable IPA, in the absence of positive serum galactomannan or histopathologic evidence of angio-invasion. Discrimination between Aspergillus airways colonization and CAPA is difficult. Distinct physiopathology and cytokine profiles of influenza and COVID-19 may explain these discrepancies. Whether CAPA represents a distinct entity is still debatable and many questions remain unanswered, such as its actual incidence, the predisposing role of corticosteroids or immunomodulatory drugs, and the indications for antifungal therapy.

Invasive pulmonary aspergillosis associated with COVID-19 in a kidney transplant recipient

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) might increase the risk of invasive pulmonary aspergillosis (IPA). Although several case reports and small series have been reported in the general population, scarce information is available regarding coronavirus disease 2019 (COVID-19)-associated IPA in the setting of solid organ transplantation. We describe a case of a kidney transplant recipient with severe COVID-19 that was subsequently diagnosed with probable IPA on the basis of the repeated isolation of Aspergillus fumigatus in sputum cultures, repeatedly increased serum (1 → 3)-β-d-glucan levels, and enlarging cavitary nodules in the CT scan. The evolution was favorable after initiation of isavuconazole and nebulized liposomal amphotericin B combination therapy and the withdrawal of immunosuppression.