1495. Aspergillosis Complicating Severe Influenza in ICU Patients: A Retrospective Cohort Study

BACKGROUND: Invasive pulmonary aspergillosis (IPA) has been recognized as a complication of influenza infection even in immunocompetent patients. We aimed to understand the incidence of IPA among critically ill patients with influenza infection over multiple seasons. METHODS: A retrospective cohort study was conducted in a single center in Chicago. Data was collected over 9 seasons (March 2009-March 2018) from all adult patients admitted to the ICU at a large urban tertiary care center with influenza. Patients were included if they had a positive influenza PCR test, were ≥ 18 years, were admitted to the ICU with respiratory distress, and treated for IPA. IPA was defined per both the EORTC/MSG criteria as well as the revised AspICU criteria. Descriptive statistics were calculated. In univariable analysis, we compared categorical variables by Fisher’s exact test and continuous variables by Wilcoxon Rank Sum where appropriate. RESULTS: A total of 224 patients with influenza were admitted to the ICU over the study period. The overall rate of IPA in the study population was low at 3.1% (7/224). Factors associated with development of IPA in those with severe influenza pneumonia were history of stem cell transplant (p=0.015). There was a numerical trend towards significance in those with history of hematological malignancy (p=0.09), lung disease (p=0.098) and obesity (p=0.051). There was significantly increased length of stay in those with IPA (p=0.046). There were no significant difference in outcomes such as need for mechanical ventilation, renal replacement therapy, or death. Other coinfections were common with incidences of 31.3% (bacterial), 7.6% (viral), and 8.9% (non-aspergillosis fungi). Baseline Characteristics and Mortality/Morbidity [Image: see text] Patient Characteristics in Invasive Pulmonary Aspergillosis [Image: see text] CONCLUSION: The incidence of IPA was significantly lower (3.1%) in our study over 9 influenza seasons than has been reported in similar studies. History of stem cell transplant was a risk factor strongly associated with the development of IPA. IPA did not significantly predict morbidity and mortality among critically ill influenza patients. DISCLOSURES: Michael G. Ison, MD MS, AlloVir (Consultant)