Clinical manifestations and risk factors for mortality of patients with severe influenza during the 2016-2018 season.

Abstract Objectives Influenza remains a crucial transmissible disease from community. We aim to identify risk factors associated with mortality among hospitalized patients with severe influenza. Methods We retrospectively reviewed medical records of adult patients with laboratory-confirmed severe influenza at a medical center between January 2016 and December 2018. The primary outcome was 30-day all-cause mortality. Results Totally 96 patients were enrolled, with 73 patients in the influenza A group and 23 in the influenza B group. Eighteen (18.8%) deaths occurred within 30 days of hospitalization, including 8 (11%) and 10 (43.5%) of each group. In multivariable Cox regression analysis, factors associated with mortality were underlying diseases of liver cirrhosis (adjusted hazard ratio [AHR], 3.94; 95% CI, 1.07–14.45) and rheumatologic diseases (AHR, 7.45; 95% CI, 2.34–23.69) and the diagnosis of influenza B (AHR, 4.33; 95% CI, 1.68–11.13). Conclusions Clinician should early identify high-risk population and warning signs of severe influenza. Our results support the policy of quadrivalent influenza vaccination because influenza B could be associated with high mortality.