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.

Keywords: Influenza A; Influenza B; Liver cirrhosis; Risk factor; Severe influenza.