Validation of real-time PCR as a diagnostic tool in aspergillosis associated with COVID-19 in patients hospitalized at Clínica Dávila at Santiago, Chile, during the years 2020 and 2021

Abstract

Background: Since the beginning of the COVID-19 pandemic, there have been cases of pulmonary aspergillosis infections associated with this infection, which has different characteristics from classical pulmonary aspergillosis and therefore, have been diagnostic challenges. Aim: To validate a commercial real-time PCR (RT-PCR) method as an alternative diagnostic tool to the galactomannan (GM) technique in the diagnosis of COVID-19-associated pulmonary aspergillosis (CAPA). Methods: Results of RT-PCR of Aspergillus spp and GM in broncho-alveolar lavage (BAL) of 72 patients hospitalized for COVID-19 at Clínica Dávila between 2020 and 2021 were analyzed. Of these patients, 33 presented CAPA. Results: The RT-PCR for Aspergillus and GM showed a positive correlation (r=0.6351, p-value <0.0001). The RT-PCR for Aspergillus technique presented a sensitivity (S), specificity (S), positive predictive value (PPV) and negative predictive value (NPV) of 100, 44, 66 and 100% respectively, while the GM technique presented 64, 89, 84 and 73%, respectively for BAL. Using both techniques in combination a S, E, PPV and NPV of 100, 82, 88 and 100% were obtained respectively.  Conclusion: This study concluded that using RT-PCR and GM techniques in combination in BAL improved the performance parameters of both techniques from those used individually to diagnose CAPA. Further studies are required to evaluate the performance of combined techniques in other aspergillosis focus.