Influence of influenza A virus in COVID-19 patients: A retrospective cohort study

Abstract

Background and objective: Coronavirus disease (COVID-19) is currently an urgent global issue, but we cannot ignore the impact of influenza A since there is an overlap of infection time and region and similar clinical manifestations and chest computed tomography (CT) images for influenza A and COVID-19 infections. We compared patients who had a COVID-19 infection and co-infection with the influenza A virus.Methods: We retrospectively reviewed patients who met the inclusion criteria for this study.Results: There were 213 patients included in this study, of whom 106 were females and 107 were males, with a median age of 63 years. All patients were diagnosed with COVID-19 and were subsequently divided into influenza positive (n = 97) and influenza negative (n = 116) groups according to the serum test results for the influenza A IgM antibody. The two groups had similar symptoms, outcomes, CT manifestation and CT scores, except for lymphadenopathy (6.2% in the influenza positive group vs. 14.7% in the negative group, P = 0.047). However, in the subgroup analysis, male or younger patients (age <= 60 years) in the influenza negative group had higher CT scores than patients in the influenza positive group (P < 0.05).Conclusions: COVID-19 patients who had co-infection with the influenza A virus showed similar symptoms, outcomes, CT manifestation and CT scores to influenza negative patients. However, male patients and younger patients had higher CT scores in the influenza negative group.