Pulmonary Aspergillosis in Critically Ill COVID-19 Patients Admitted to the Intensive Care Unit: A Retrospective Cohort Study

Pharmacokinetics of isavuconazole at different target sites in healthy volunteers after single and multiple intravenous infusions

BACKGROUND

Invasive aspergillosis is a severe fungal infection that affects multiple organ systems including the CNS and the lungs. Isavuconazole, a novel triazole antifungal agent, has demonstrated promising activity against Aspergillus spp. However, data on the penetration of isavuconazole into the CNS and ELF and intracellular accumulation remain limited.

MATERIALS AND METHODS

We conducted a prospective single-centre pharmacokinetic (PK) study in 12 healthy volunteers. Subjects received seven doses of 200 mg isavuconazole to achieve an assumed steady-state. After the first and final infusion, plasma sampling was conducted over 8 and 12 h, respectively. All subjects underwent one lumbar puncture and bronchoalveolar lavage, at either 2, 6 or 12 h post-infusion of the final dose. PBMCs were collected in six subjects from blood to determine intracellular isavuconazole concentrations at 6, 8 or 12 h. The AUC/MIC was calculated for an MIC value of 1 mg/L, which marks the EUCAST susceptibility breakpoint for Aspergillus fumigatus and Aspergillus flavus.

RESULTS

C max and AUC0-24h of isavuconazole in plasma under assumed steady-state conditions were 6.57 ± 1.68 mg/L (mean ± SD) and 106 ± 32.1 h·mg/L, respectively. The average concentrations measured in CSF, ELF and in PBMCs were 0.07 ± 0.03, 0.94 ± 0.46 and 27.1 ± 17.8 mg/L, respectively. The AUC/MIC in plasma, CSF, ELF and in PBMCs under steady-state conditions were 106 ± 32.1, 1.68 ± 0.72, 22.6 ± 11.0 and 650 ± 426 mg·h/L, respectively.

CONCLUSION

Isavuconazole demonstrated moderate penetration into ELF, low penetrability into CSF and high accumulation in PBMCs. Current dosing regimens resulted in sufficient plasma exposure in all subjects to treat isolates with MICs ≤ 1 mg/L.

Risk factors for COVID-19-associated pulmonary aspergillosis: a systematic review and meta-analysis

BACKGROUND

COVID-19-associated pulmonary aspergillosis (CAPA) has been reported to be an emerging and potentially fatal complication of severe COVID-19. However, risk factors for CAPA have not been systematically addressed to date.

METHODS

In this systematic review and meta-analysis to identify factors associated with CAPA, we comprehensively searched five medical databases: Ovid MEDLINE; Ovid Embase; the Cochrane Database of Systematic Reviews; the Cochrane Central Register of Controlled Trials; and the WHO COVID-19 Database. All case-control and cohort studies in adults (aged >18 years) that described at least six cases of CAPA and evaluated any risk factors for CAPA, published from Dec 1, 2019, to July 27, 2023, were screened and assessed for inclusion. Only studies with a control population of COVID-19-positive individuals without aspergillosis were included. Two reviewers independently screened search results and extracted outcome data as summary estimates from eligible studies. The primary outcome was to identify the factors associated with CAPA. Meta-analysis was done with random-effects models, with use of the Mantel-Haenszel method to assess dichotomous outcomes as potential risk factors, or the inverse variance method to assess continuous variables for potential association with CAPA. Publication bias was assessed with funnel plots for factors associated with CAPA. The study is registered with PROSPERO, CRD42022334405.

FINDINGS

Of 3561 records identified, 27 articles were included in the meta-analysis. 6848 patients with COVID-19 were included, of whom 1324 (19·3%) were diagnosed with CAPA. Diagnosis rates of CAPA ranged from 2·5% (14 of 566 patients) to 47·2% (58 of 123). We identified eight risk factors for CAPA. These factors included pre-existing comorbidities of chronic liver disease (odds ratio [OR] 2·70 [95% CI 1·21-6·04], p=0·02; I2=53%), haematological malignancies (OR 2·47 [1·27-4·83], p=0·008; I2=50%), chronic obstructive pulmonary disease (OR 2·00 [1·42-2·83], p<0·0001; I2=26%), and cerebrovascular disease (OR 1·31 [1·01-1·71], p=0·05; I2=46%). Use of invasive mechanical ventilation (OR 2·83; 95% CI 1·88-4·24; p<0·0001; I2=69%), use of renal replacement therapy (OR 2·26 [1·76-2·90], p<0·0001; I2=14%), treatment of COVID-19 with interleukin-6 inhibitors (OR 2·88 [1·52-5·43], p=0·001; I2=89%), and treatment of COVID-19 with corticosteroids (OR 1·88 [1·28-2·77], p=0·001; I2=66%) were also associated with CAPA. Patients with CAPA were typically older than those without CAPA (mean age 66·6 years [SD 3·6] vs 63·5 years [5·3]; mean difference 2·90 [1·48-4·33], p<0·0001; I2=86%). The duration of mechanical ventilation in patients with CAPA was longer than in those without CAPA (n=7 studies; mean duration 19·3 days [8·9] vs 13·5 days [6·8]; mean difference 5·53 days [1·30-9·77], p=0·01; I2=88%). In post-hoc analysis, patients with CAPA had higher all-cause mortality than those without CAPA (n=20 studies; OR 2·65 [2·04-3·45], p<0·0001; I2=51%).

INTERPRETATION

The identified risk factors for CAPA could eventually be addressed with targeted antifungal prophylaxis in patients with severe COVID-19.

FUNDING

None.

Epidemiology and Azole Resistance of Clinical Isolates of Aspergillus fumigatus from a Large Tertiary Hospital in Ningxia, China

Purpose

The objective of this study was to determine the clinical distribution, in vitro antifungal susceptibility and underlying resistance mechanisms of Aspergillus fumigatus (A. fumigatus) isolates from the General Hospital of Ningxia Medical University between November 2021 and May 2023.

Methods

Antifungal susceptibility testing was performed using the Sensititre YeastOne YO10, and isolates with high minimal inhibitory concentrations (MICs) were further confirmed using the standard broth microdilution assays established by the Clinical and Laboratory Standards Institute (CLSI) M38-third edition. Whole-Genome Resequencing and RT-qPCR in azole-resistant A. fumigatus strains were performed to investigate the underlying resistance mechanisms.

Results

Overall, a total of 276 A. fumigatus isolates were identified from various clinical departments, showing an increasing trend in the number of isolates over the past 3 years. Two azole-resistant A. fumigatus strains (0.72%) were observed, one of which showed overexpression of cyp51A, cyp51B, cdr1B, MDR1/2, artR, srbA, erg24A, and erg4B, but no cyp51A mutation. However, the other strain harbored two alterations in the cyp51A sequences (L98H/S297T). Therefore, we first described two azole-resistant clinical A. fumigatus strains in Ningxia, China, and reported one azole-resistant strain that has the L98H/S297T mutations in the cyp51A gene without any tandem repeat (TR) sequences in the promoter region.

Conclusions

This study emphasizes the importance of enhancing attention and surveillance of azole-resistant A. fumigatus, particularly those with non-TR point mutations of cyp51A or non-cyp51A mutations, in order to gain a better understanding of their prevalence and spread in the region.

Clinical courses and outcomes of COVID-19 associated pulmonary aspergillosis in 168 patients with the SARS-CoV-2 omicron variant

PURPOSE

We aimed to analyze the clinical features of COVID-19-associated pulmonary aspergillosis (CAPA) during the SARS-CoV-2 Omicron variant pandemic and to reveal the risk factors for CAPA and death.

METHODS

A retrospective cohort study was conducted on 168 CAPA patients from December 8, 2022 to January 31, 2023. 168 COVID-19 patients without secondary fungal infection during this period were matched 1:1 using propensity score matching as controls.

RESULTS

The incidence of CAPA was 3.8% (168/4421). Compared with patients without fungal infection, CAPA patients had a higher mortality (43.5% vs. 10.1%, P < 0.001). Patients in the death group (n = 73) were more likely to be admitted to ICU (91.8% vs. 26.3%, p < 0.001), had a shorter ICU length of hospitalization (10 (IQR, 6 ~ 16.5) days vs. 14 (IQR, 8 ~ 37) days, p = 0.012). Immunocompromised status (p = 0.023), NLR ≥ 5.7 (p = 0.004), CRP ≥ 50 mg/L (p = 0.043), and the number of antibiotics ≥ 3 (p < 0.001) were all risk factors for CAPA; NLR ≥ 5.7 (p = 0.009) and the number of antibiotics ≥ 3 (p = 0.018) were all independent risk factors for death.

CONCLUSIONS

During the Omicron variant pandemic, CAPA increased death and ICU length of hospitalization. The risk factors of CAPA and death obtained from the study can help us further understand the disease characteristics of CAPA and better guide our clinical decision-making.

Invasive pulmonary aspergillosis in the ICU: tale of a broadening risk profile

PURPOSE OF REVIEW

In the absence of histopathological proof, the diagnosis of invasive pulmonary aspergillosis (IPA) is usually based on mycology (not on tissue), medical imaging, and the patient's risk profile for acquiring invasive fungal disease. Here, we review the changes in risk profile for IPA that took place over the past decades.

RECENT FINDINGS

In the early 2000s IPA was considered exclusively a disease of immunocompromised patients. Particularly in the context of critical illness, the risk profile has been broadened steadily. Acute viral infection by influenza or SARS-Cov-2 are now well recognized risk factors for IPA.

SUMMARY

The classic risk profile ('host factors') reflecting an immunocompromised status was first enlarged by a spectrum of chronic conditions such as AIDS, cirrhosis, and chronic obstructive pulmonary disease. In the presence of critical illness, especially characterized by sepsis and/or severe respiratory distress, any chronic condition could add to the risk profile. Recently, acute viral infections have been associated with IPA leading to the concepts of influenza-associated IPA and COVID-19-associated IPA. These viral infections may affect patients without underlying disease. Hence, the risk for IPA is now a reality for ICU patients, even in the absence of any chronic conditions.