Table 1 Proposed case definition for IAPA in ICU patients Entry criteria: influenza-like illness + positive influenza PCR or antigen + temporally relationship Aspergillus tracheobronchitis IAPA in patients without documented Aspergillus tracheobronchitis Proven Biopsy or brush specimen of airway plaque, pseudomembrane or ulcer showing hyphal elements and Aspergillus growth on culture or positive Aspergillus PCR in tissue Lung biopsy showing invasive fungal elements and Aspergillus growth on culture or positive Aspergillus PCR in tissue Probable Airway plaque, pseudomembrane or ulcer and at least one of the following: Serum GM index > 0.5 or BAL GM index ≥ 1.0 or Positive BAL culture or Positive tracheal aspirate culture or Positive sputum culture or Hyphae consistent with Aspergillus A: Pulmonary infiltrate and at least one of the following: Serum GM index > 0.5 or BAL GM index ≥ 1.0 or Positive BAL culture OR B: Cavitating infiltrate (not attributed to another cause) and at least one of the following: Positive sputum culture or Positive tracheal aspirate culture