Serological detection of invasive pulmonary aspergillosis in severely ill COVID-19 patients

COVID-19-associated pulmonary aspergillosis (CAPA) is a serious invasive fungal infection impacting critically ill patients. Diagnosis is challenging due to overlapping clinical and radiographic features with severe COVID-19, and difficulty distinguishing true tissue invasion from transient Aspergillus colonization. This study aimed to investigate the incidence, risk factors, clinical outcomes of CAPA among ICU patients in Egypt, and to assess the diagnostic performance of serum B-D glucan (BDG) and galactomannan (GM) in diagnosing CAPA.

Seventy-nine COVID-19 ICU patients were enrolled. CAPA was defined using two widely recognized approaches: the ECMM/ISHAM consensus and modified AspICU criteria. Serum BDG and GM assays were used for diagnosis.

Probable CAPA was observed in 12.7 % of patients, possible CAPA in 6.3 %, Aspergillus colonization in 12.7 %. Advanced age and prolonged ICU stay were risk factors in univariate analysis (p = 0.045 and 0.041, respectively) but were not significant in multivariate models (p = 0.703 and 0.257, respectively). Cancer significantly increased CAPA risk in both univariate (p = 0.035) and multivariate analyses (p = 0.043). Mortality was higher in CAPA patients (73.3 %) compared with non-CAPA patients (45.3 %). Serum BDG and GM demonstrated sensitivities of 66.7 % and specificities of 89.1 % and 93.8 %, respectively, which improved to 90-100 % sensitivity and 100 % specificity using the modified AspICU criteria (p < 0.001).

Timely detection and precise diagnosis of CAPA in severely ill patients are essential to guide management and improve outcomes. Serum BDG and GM showed valuable diagnostic potential, particularly when used within established diagnostic algorithms.