CT findings of COVID-19-associated pulmonary aspergillosis: a systematic review and individual patient data analysis

Influenza-associated and COVID-19-associated pulmonary aspergillosis in critically ill patients

Influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA) are increasingly recognised as important complications in patients requiring intensive care for severe viral pneumonia. The diagnosis can typically be made in 10-20% of patients with severe influenza or COVID-19, but only when appropriate diagnostic tools are used. Bronchoalveolar lavage sampling for culture, galactomannan testing, and PCR forms the cornerstone of diagnosis, whereas visual examination of the tracheobronchial tract during bronchoscopy is required to detect invasive Aspergillus tracheobronchitis. Azoles are the first-choice antifungal drugs, with liposomal amphotericin B as an alternative in settings where azole resistance is prevalent. Despite antifungal therapy, IAPA and CAPA are associated with poor outcomes, with fatality rates often exceeding 50%. In this Review, we discuss the mechanistic and clinical aspects of IAPA and CAPA. Moreover, we identify crucial knowledge gaps and formulate directions for future research.

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.

Risk factors for COVID-19 associated pulmonary aspergillosis and outcomes in patients with acute respiratory failure in a respiratory sub-intensive care unit

BACKGROUND

COVID-19-associated pulmonary aspergillosis (CAPA) is burdened by high mortality. Data are lacking about non-ICU patients. Aims of this study were to: (i) assess the incidence and prevalence of CAPA in a respiratory sub-intensive care unit, (ii) evaluate its risk factors and (iii) impact on in-hospital mortality. Secondary aims were to: (i) assess factors associated to mortality, and (ii) evaluate significant features in hematological patients.

MATERIALS AND METHODS

This was a single-center, retrospective study of COVID-19 patients with acute respiratory failure. A cohort of CAPA patients was compared to a non-CAPA cohort. Among patients with CAPA, a cohort of hematological patients was further compared to another of non-hematological patients.

RESULTS

Three hundred fifty patients were included in the study. Median P/F ratio at the admission to sub-intensive unit was 225 mmHg (IQR 155-314). 55 (15.7%) developed CAPA (incidence of 5.5%). Eighteen had probable CAPA (37.3%), 37 (67.3%) possible CAPA and none proven CAPA. Diagnosis of CAPA occurred at a median of 17 days (IQR 12-31) from SARS-CoV-2 infection. Independent risk factors for CAPA were hematological malignancy [OR 1.74 (95%CI 0.75-4.37), p = 0.0003], lymphocytopenia [OR 2.29 (95%CI 1.12-4.86), p = 0.02], and COPD [OR 2.74 (95%CI 1.19-5.08), p = 0.014]. Mortality rate was higher in CAPA cohort (61.8% vs 22.7%, p < 0.0001). CAPA resulted an independent risk factor for in-hospital mortality [OR 2.92 (95%CI 1.47-5.89), p = 0.0024]. Among CAPA patients, age > 65 years resulted a predictor of mortality [OR 5.09 (95% CI 1.20-26.92), p = 0.035]. No differences were observed in hematological cohort.

CONCLUSION

CAPA is a life-threatening condition with high mortality rates. It should be promptly suspected, especially in case of hematological malignancy, COPD and lymphocytopenia.

Point-of-care testing for viral-associated pulmonary aspergillosis

INTRODUCTION

Over the last years, severe respiratory viral infections, particularly those caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the influenza virus, have emerged as risk factor for viral-associated pulmonary aspergillosis (VAPA) among critically ill patients. Delays in diagnosis of VAPA are associated with increased mortality. Point-of-care-tests may play an important role in earlier diagnosis of VAPA and thus improve patient outcomes.

AREAS COVERED

The following review will give an update on point-of-care tests for VAPA, analyzing performances in respiratory and blood specimens.

EXPERT OPINION

Point-of-care tests have emerged, and particularly the IMMY Aspergillus galactomannan lateral flow assay (LFA) shows performances comparable to the galactomannan ELISA for diagnosis of VAPA. Notably, nearly all evaluations of POC tests for VAPA have been performed in COVID-19 patients, with very limited data in influenza patients. For early diagnosis of COVID associated pulmonary aspergillosis (CAPA), the LFA has shown promising performances in respiratory samples, particularly in bronchoalveolar lavage fluid, and may thereby help in improving patient outcomes. In contrast, serum LFA testing may not be useful for early diagnosis of disease, except in cases with invasive tracheobronchial aspergillosis.

COVID-19-associated pulmonary aspergillosis in intensive care unit: A real-life experience

Since 2020, cases of COVID-19-associated pulmonary aspergillosis (CAPA) have been frequently described, representing an important cause of mortality, especially among patients admitted to intensive care unit (ICU). A predisposition to invasive infection caused by Aspergillus spp. in SARS-CoV-2 infected patients can be ascribed either to the direct viral-mediated damage of the respiratory epithelium or to the dysregulated immunity associated with COVID-19. In this case series we have collected the clinical, laboratory and radiological data of 10 patients admitted to the ICU with diagnosis of probable CAPA, according to the recent expert consensus statement, from March 2020 to December 2022 in the Teaching Hospital of Catanzaro in Italy. Overall, 249 patients were admitted to the COVID-19-ICU from March 2020 to December 2022; out of these, 4% developed a probable CAPA. Most of patients were male with a mean age of 62 years. Only two patients had an underlying immunocompromising condition. The observed mortality was 70%. In our institution, all COVID-19 patients requiring invasive mechanical ventilation systematically underwent bronchoscopy with bronchoalveolar lavage for an early evaluation of bacterial and/or fungal co- or super-infections, including galactomannan test. Patients were re-evaluated by an infectious diseases consultant team every 24-48 hours and the galactomannan test was systematically repeated based on patient's clinical course. Even though the numbers in this study are very small, we report our experience about the role of early diagnosis and careful choice of antifungal therapy, considering the fragility of these patients, and its relationship with outcomes. Despite a systemic approach allowing early diagnosis and initiation of anti-fungal therapy, the mortality rate turned out to be very high (70%).

Imaging Findings in Aspergillosis: From Head to Toe

Aspergillosis is a mycotic infection induced by airborne fungi that are ubiquitous. Inhalation of Aspergillus conidia results in transmission through the respiratory tract. The clinical presentation is dependent on organism and host specifics, with immunodeficiency, allergies, and preexisting pulmonary disease constituting the most important risk factors. In recent decades, the incidence of fungal infections has increased dramatically, due in part to the increased number of transplants and the pervasive use of chemotherapy and immunosuppressive drugs. The spectrum of clinical manifestations can range from an asymptomatic or mild infection to a swiftly progressive, life-threatening illness. Additionally, invasive infections can migrate to extrapulmonary sites, causing infections in distant organs. Recognition and familiarity with the various radiological findings in the appropriate clinical context are essential for patient management and the prompt initiation of life-saving treatment. We discuss the radiological characteristics of chronic and invasive pulmonary aspergillosis, as well as some of the typically unexpected extrapulmonary manifestations of disseminated disease.

Significance of Aspergillus spp. isolation in defining cases of COVID-19 Associated Pulmonary Aspergillosis - CAPA

COVID-19-Associated Pulmonary Aspergillosis (CAPA) is a relatively common complication in patients with severe forms of the disease caused by the SARS-CoV-2 virus. Diagnosing and confirming CAPA is challenging. In this study, Aspergillus spp. isolation in respiratory specimens from patients with COVID-19 was evaluated for identifying cases of CAPA. In 2020‒2021, 17 Aspergillus spp. were isolated from 15 COVID-19 patients admitted to a university hospital in Brazil. Patient records were retrospectively reviewed to obtain clinical-epidemiological data and other markers of Aspergillus spp. infection and then compared with the ECMM/ISHAM criteria for defining CAPA. Probable CAPA was defined in 5/10 patients, who had Aspergillus spp. isolated from Bronchoalveolar Lavage (BAL) or a positive galactomannan blood test. Additionally, anti-Aspergillus antibodies were detected in two of these patients, during active or follow-up phases of CAPA. In another seven patients with Aspergillus spp. isolated from tracheobronchial aspirate or sputum, CAPA was presumed, mainly due to deterioration of clinical conditions and new lung imaging suggestive of fungal infection. Antifungal agents to control CAPA, particularly voriconazole, were used in 9/15 cases. In cases of probable CAPA and remaining patients, clinical conditions and comorbidities were similar, with lethality being high, at 60% and 71%, respectively. The number of CAPA cases defined by scientific criteria was lower than that assumed in the clinical context. This was largely due to the lack of BAL collection for fungal culture and the non-intensive use of other markers of invasive aspergillosis. The isolation of Aspergillus spp. in different respiratory specimens should alert clinicians to the diagnosis of CAPA.