Gender differences and influenza-associated mortality in hospitalized influenza A patients during the 2018/19 season

Background In this study we analyzed gender differences in the clinical presentation of patients with molecular confirmed influenza A. Additionally, we tried to identify predictors of influenza-associated mortality. Materials/methods In this prospective observational multi-center-study we included all influenza-positive patients ≥ 18 years who were hospitalized and treated on flu-isolation-wards in three hospitals in Vienna during the 2018/19 influenza season. Diagnoses were made via Cobas ® Liat ® POCT. Results 490 Patients (48.8% female) tested positive for influenza A. Female patients were older (median age 76 years vs. 70 years, p 75 years (OR 5.49, 95% CI 1.10–27.43), acute heart failure (OR 3.56, 95% CI 1.03–12.05) and ICU admission (OR 6.1, 95% CI 0.98–37.91) were predictors for in-hospital mortality for female patients, while any malignancy (OR 9.4, 95% CI 1.90–46.54) and ICU admission (OR 7.05, 95% CI 1.44–34.55) were predictors in male patients. Conclusions Gender is associated with differences in clinical presentation and complications of influenza A virus infection. Women with acute heart failure or aged > 75 years have an increased risk of influenza associated in-hospital mortality, while ICU admission and any malignancy are predictors for male patients. Mortality rates in patients > 75 years are 5–10 times higher compared to their non-hospitalized influenza-negative Austrian counterparts.