Prospective Observational Trial of IAPA

A prospective multi-center observational study to assess the incidence of influenza-associated pulmonary aspergillosis (IAPA) in ICU patients and to identify host- and pathogen related risk factors for IAPA in EORTC negative ICU patients with severe influenza.

Inclusion Criteria: * Patients with a PCR-positive respiratory virus panel (RVP) result for influenza within 96 hours before or 48 hours after ICU admission. * Patients who require ICU admission for more than 24 hours for severe influenza. * Patients who have respiratory distress (respiratory rate \>= 25x/minute and paO2/fiO2 \< 300 with or without bilateral infiltrates) as the main reason for ICU admission. * Patients who do not have an EORTC host factor. * Patients who are at least 18 years of age. Exclusion Criteria: * Patients with age \< 18 years as extensive sampling is required * Expected survival on ICU admission ≤ 48h * Patients that are being treated actively with antifungal agents for invasive aspergillosis. * Patients or their legal representatives who did not sign the informed consent form