ABSTRACT
Several reports have been published on Aspergillus findings in COVID-19 patients leading to a proposition of new disease entity COVID-19-associated pulmonary aspergillosis. This scoping review is designed at clarifying the concepts on how the findings of Aspergillus spp. in COVID-19 patients were interpreted. We searched Medline to identify the studies on Aspergillus spp. findings in COVID-19 patients. Included were observational studies containing the following information: explicit mention of the total number of the study population, study period, reason for obtaining respiratory samples, case definition, and clinical outcomes. Excluded were case series, case reports and reviews. Identified were 123 publications, and 8 observational studies were included. From the included studies the following issues were identified. The proportion of immunocompromised patients considered as host factors varied from 0 to 17%. Most of the studies did not mention radiographic findings explicitly. Respiratory samples were mostly obtained to investigate clinical deterioration. Aspergillus culture, antigen or PCR testing on bronchoalveolar lavage (BAL) fluid were performed in between 23.3% and 66.3% of the study population. Two studies performed periodic samples of BAL. Galactomannan index (GI) positivity in BAL was between 10% and 28%. GI in blood was found in 0.9% to 6.7% of the available samples. The prevalence of COVID-19-associated pulmonary aspergillosis ranged from 2.7% to 27.7%. Studies compared the mortality between defined cases and non-cases, and all showed increased mortality in cases. No studies showed that antifungal treatment reduced mortality. Concluding, this review showed how studies defined the clinical entity COVID-19-associated pulmonary aspergillosis where positive Aspergillus test in the respiratory sample was the main driver for the diagnosis. There were many differences between studies in terms of test algorithm and Aspergillus test used that largely determined the prevalence. Whether antifungal therapy, either as prophylaxis, pre-emptive or targeted therapy will lead to better outcomes of COVID-19-associated pulmonary aspergillosis patients is still need to be answered.
ABSTRACT
The aim of this study was to describe the frequency of positive Aspergillus tests in COVID-19 patients and investigate the association between COVID-19 and a positive Aspergillus test result. We compared the proportion of positive Aspergillus tests in COVID-19 patients admitted to the intensive care unit (ICU) for >24 h with two control groups: patients with community-acquired pneumonia with (i) a PCR-confirmed influenza infection (considered a positive control since the link between influenza and invasive aspergillosis has been established) and (ii) Streptococcus pneumoniae pneumonia (in whom positive Aspergillus tests are mostly considered as colonization). During the study period, 92 COVID-19 patients (mean [standard deviation] age, 62 [14] years; 76.1% males), 48 influenza patients (55 [14]; 56.2% males), and 65 pneumococcal pneumonia patients (58 [15], 63,1% males) were identified. Any positive Aspergillus test from any respiratory sample was found in 10.9% of the COVID-19 patients, 6.2% of the patients with pneumococcal pneumonia, and 22.9% of those infected with influenza. A positive culture or PCR or galactomannan test on bronchoalveolar lavage (BAL) fluid only was found in 5.4% of COVID-19 patients, which was lower than in patients with influenza (18.8%) and comparable to that in the pneumococcal pneumonia group (4.6%). Using logistic regression analysis, the odds ratio (OR) (95% confidence interval) for a positive Aspergillus test on BAL fluid for COVID-19 patients was 1.2 (0.3 to 5.1; P = 0.8) compared to the pneumococcal pneumonia group, while it was 0.2 (0.1 to 0.8; P = 0.02) compared to the influenza group. This difference remained significant when corrected for age and sex. In conclusion, in COVID-19 patients, the prevalence of a positive Aspergillus test was comparable to that in patients admitted for pneumococcal pneumonia but substantially lower than what we observed in patients with influenza.