COVID-19-Associated Pulmonary Aspergillosis (CAPA)

Abstract

Invasive Pulmonary Aspergillosis (IPA) has been recognized as a possible secondary infection complicating Coronavirus disease 2019 (COVID-19) and increasing mortality. The aim of this review was to report and summarize the available data in the literature concerning the incidence, pathophysiology, diagnosis, and treatment of COVID-19-Associated Pulmonary Aspergillosis (CAPA). Currently, the incidence of CAPA is unclear due to different definitions and diagnostic criteria used among the studies. It was estimated that approximately 8.6% (206/2383) of mechanically ventilated patients were diagnosed with either proven, probable, or putative CAPA. Classical host factors of invasive aspergillosis are rarely recognized in patients with CAPA, who are mainly immuno-competent presenting with comorbidities, while the role of steroids warrants further investigation. Direct epithelial injury and diffuse pulmonary micro thrombi in combination with immune dysregulation, hyper inflammatory response, and immunosuppressive treatment may be implicated. Discrimination between two forms of CAPA (e.g., tracheobronchial and parenchymal) is required, whereas radiological signs of aspergillosis are not typically evident in patients with severe COVID-19 pneumonia. In previous studies, the European Organization for Research and Treatment of Cancer/Mycoses Study Group (EORTC/MSG) criteria, a clinical algorithm to diagnose Invasive Pulmonary Aspergillosis in intensive care unit patients (AspICU algorithm), and influenza-associated pulmonary aspergillosis (IAPA) criteria were used for the diagnosis of proven/probable and putative CAPA, as well as the differentiation from colonization, which can be challenging. Aspergillus fumigatus is the most commonly isolated pathogen in respiratory cultures. Bronchoalveolar lavage (BAL) and serum galactomannan (GM), β-d-glucan (with limited specificity), polymerase chain reaction (PCR), and Aspergillus-specific lateral-flow device test can be included in the diagnostic work-up; however, these approaches are characterized by low sensitivity. Early treatment of CAPA is necessary, and 71.4% (135/189) of patients received antifungal therapy, mainly with voriconazole, isavuconazole, and liposomal amphotericin B . Given the high mortality rate among patients with Aspergillus infection, the administration of prophylactic treatment is debated. In conclusion, different diagnostic strategies are necessary to differentiate colonization from bronchial or parenchymal infection in intubated COVID-19 patients with Aspergillus spp. in their respiratory specimens vs. those not infected with severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2). Following confirmation, voriconazole or isavuconazole should be used for the treatment of CAPA.