Predictors of Fatality in Influenza A Virus Subtypes Infection among inpatients in 2015-2016 season

Abstract Background Influenza A infection could cause to severe disease and mortality. The effect of different subtypes of Influenza on morbidity and mortality is not known yet in Turkey Objectives We aimed to describe the predictors for fatality related to influenza A infection among hospitalized patients in Istanbul in 2015-2016 influenza season, and to detail the differences between H3N2 and H1N1. Study design This is a multicenter study performed by Istanbul respiratory infections study group of The Turkish Society of Clinical Microbiology and Infectious Diseases (KLIMIK), among the patients, who were hospitalized for influenza in 2015-2016 influenza season in Istanbul. Results In 2015-2016 season, 222 hospitalized, laboratory-confirmed influenza cases were included, 25 (11.2%) died. The fatality rate was significantly higher among the patients older than 65 years, and the patients with chronic heart and kidney diseases (p  65 years old, (OR: 6.9, CI: 2.07-23.08, p = 0.002), being infected with influenza A(H3N2) (OR: 4.2, CI: 1.27-14.38, p = 0.019), and one-day delay in antiviral use (OR:1.28, CI:1.01-1.63, p = 0.036) were found to be increased the likelihood of fatality. Conclusions The case fatality rate of Influenza A(H3N2) was significantly higher than influenza A(H1N1). Detection of the infection, allowing opportunity for the early use of antiviral agents, was found to be important for prevention of fatality. The vaccination should be prioritized for at-risk groups.