COVID-19 Is Not the Flu: Four Graphs From Four Countries

Area of Science:

• Epidemiology
• Public Health
• Infectious Diseases

Background:

• The COVID-19 pandemic prompted widespread public health interventions.
• These measures likely influenced the transmission dynamics of other respiratory viruses, including influenza.
• Understanding this interaction is crucial for managing respiratory disease outbreaks.

Purpose of the Study:

• To investigate the impact of COVID-19 mitigation strategies on seasonal influenza patterns.
• To compare influenza trends with COVID-19 spread across hemispheres.

Main Methods:

• Utilized WHO FluNet and Johns Hopkins University COVID-19 case data.
• Analyzed longitudinal data from 2016-2020 for Canada, the United States, Australia, and Brazil.
• Employed graphical presentations for data visualization.

Main Results:

• Observed a substantial decrease in influenza cases during the 2019-2020 season.
• Northern hemisphere countries saw shortened influenza seasons (4-7 weeks) and minimal fall activity.
• Southern hemisphere countries reported drastically low influenza levels post-COVID-19 measures.

Conclusions:

• COVID-19 mitigation measures were likely responsible for the significant reduction in influenza.
• Despite reduced influenza, COVID-19 (SARS-CoV-2) demonstrated greater contagiousness and higher mortality.
• COVID-19 poses a substantially greater public health threat than seasonal influenza.