Invasive aspergillosis (IA) is commonly associated with certain hematological malignancies, solid organ transplant and stem cell transplantation. Over the past years IA is more commonly reported in critically-ill patients. Factors that are associated with increased risk for IA are well characterized including neutropenia and treatment with immunosuppressive agents such as corticosteroids. However, over the past years increasing reports were published on IA associated with severe influenza pneumonia. Recent surveys indicate that between 16% and 20% of patients admitted to the ICU with influenza may develop influenza-associated invasive aspergillosis (IAA). The mortality of IAA is high (48% to 61%), which may be due to atypical clinical presentation and subsequent delayed antifungal therapy. Patients with IAA commonly do not have classic risk factors, and some patients have no previous medical history. Furthermore, the clinical presentation of IAA may be atypical as the patients might develop Aspergillus tracheobronchitis, which is not characterized by nodular lesions or the halo-sign on the CT-scan. As the fungus grows within the trachea and bronchi, bronchoscopy is the preferred diagnostic tool. Furthermore, intratracheal and intrabronchial growth allows Aspergillus to sporulate, which might increase the fungal burden in the lung and increase the probability of treatment failure. Culture of BAL or BAL-galactomannan were found to be positive in >80% of patients with IAA. Given the high risk for IAA and mortality in critically-ill patients with influenza, physicians should be aware of this co-infection and should consider IAA in any patient admitted to the ICU with influenza pneumonia. Further studies are ongoing to understand the underlying pathogenesis of IAA, which might help to identify specific risk factors.
Full conference title:
- TIMM 8th (2017)