Does COVID-19 infection impact on the trend of seasonal influenza infection? 11 countries and regions, from 2014 to 2020

Abstract

Objectives: Infection due to the 2019 novel coronavirus disease (COVID-19) is dramatically widespread around the world. The COVID-19 pandemic could increase public concern to prevent infectious disease. The present study aimed to assess the relationship between the COVID-19 epidemic and the potential decrease in seasonal influenza cases.

Methods: This study was performed to show trends in seasonal influenza cases from the 2014-2015 season to the 2019-2020 season in 11 countries and regions, and evaluate whether the trends in the 2019-2020 season were different before and after the COVID-19 pandemic compared to previous seasons using a quasi-experimental difference-in-difference design.

Results: In East Asia, the number of seasonal influenza cases in the 2019-20 season was lower after the COVID-19 transmission compared to previous years. However, this was not the case in American countries or in European countries.

Conclusion: The COVID-19 epidemic might have altered health behaviors, resulting in an unexpected reduction of seasonal influenza cases.

Keywords: COVID-19; Health behavior; Human; Influenza; Pandemics.