Non-Pharmaceutical Interventions Implemented to Control the COVID-19 Were Associated With Reduction of Influenza Incidence

Front Public Health. 2022 Feb 18:10:773271. doi: 10.3389/fpubh.2022.773271. eCollection 2022.

Abstract

Background: Non-pharmaceutical interventions were implemented in most countries to reduce the transmission of COVID-19. We aimed to describe the incidence of influenza in four countries in the 2019-2020 season and examined the effect of these non-pharmaceutical interventions on the incidence of influenza.

Methods: We used the network surveillance data from 2015 to 2020 to estimate the percentage increase in influenza cases to explore the effect of non-pharmaceutical interventions implemented to control the COVID-19 on the incidence of influenza in China, the United States, Japan, and Singapore.

Results: We found that the incidence of influenza has been almost zero and reached a persistent near-zero level for a continuous period of six months since epidemiologic week 14 of 2020 in the four countries. Influenza incidence decreased by 77.71% and 60.50% in the early days of COVID-19 in the 2019-2020 season compared to the same period in preceding years in Japan and Singapore, respectively. Furthermore, influenza incidence decreased by 60.50-99.48% during the period of compulsory interventions in the 2019-2020 season compared to the same period in preceding years in the four countries.

Conclusion: These findings suggest that the application of non-pharmaceutical interventions, even everyday preventive action, was associated with a reduction of influenza incidence, which highlights that more traditional public health interventions need to be reasserted and universalized to reduce influenza incidence.

Keywords: COVID-19; disease surveillance; influenza; non-pharmaceutical intervention; pandemic.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • China / epidemiology
  • Humans
  • Incidence
  • Influenza, Human* / epidemiology
  • Influenza, Human* / prevention & control
  • SARS-CoV-2