Influenza A-associated pulmonary aspergillosis in critically ill patients in the post-COVID-19 era: a multicenter cohort study from China

BACKGROUND: To determine the incidence, risk factors, and outcomes of invasive pulmonary aspergillosis (IPA) in critically ill patients with Influenza A pneumonia in post-COVID-19 China. METHODS: We conducted a multicenter retrospective cohort study across 21 ICUs (November 2024-February 2025) including adults with acute respiratory failure due to confirmed severe Influenza A pneumonia. IPA was defined by 2024 FUNDICU criteria. The primary outcome was 60-day all-cause mortality. RESULTS: Among 542 patients, 179 (33.0%) had IPA. Independent risk factors: renal replacement therapy (aOR 1.63), diabetes (aOR 1.79), bacterial co-infection (aOR 1.64), pre-ICU systemic glucocorticoids (aOR 2.13), and ICU steroids (aOR 1.53). Median time from influenza to IPA diagnosis was 2 days. Sixty-day mortality was higher with IPA (47.5% vs 32.0%, P < 0.001), persisting after matching. Among IPA patients, hematologic disorders (aHR 5.31) and higher CRP predicted death. CONCLUSIONS: In the post-COVID-19 era, IPA is highly prevalent and lethal in severe influenza, with rapid onset. Protocolized screening and timely diagnostic strategies are urgently needed.