Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 Aug 30;50(4):1124-1133.
doi: 10.1093/ije/dyab081.

Interactions between SARS-CoV-2 and influenza, and the impact of coinfection on disease severity: a test-negative design

Julia Stowe  1 , Elise Tessier  1 , H Zhao  1 , Rebecca Guy  2 , Berit Muller-Pebody  2 , Maria Zambon  3 , Nick Andrews  4 , Mary Ramsay  1 , Jamie Lopez Bernal  1
Affiliations

Interactions between SARS-CoV-2 and influenza, and the impact of coinfection on disease severity: a test-negative design

Julia Stowe et al. Int J Epidemiol. .

Abstract

Background: The impact of SARS-CoV-2 alongside influenza is a major concern in the northern hemisphere as winter approaches.

Methods: Test data for influenza and SARS-CoV-2 from national surveillance systems between 20 January 2020 and 25 April 2020 were used to estimate influenza infection on the risk of SARS-CoV-2 infection. A test-negative design was used to assess the odds of SARS-CoV-2 in those who tested positive for influenza compared with those who tested negative. The severity of SARS-CoV-2 was also assessed using univariable and multivariable analyses.

Results: The risk of testing positive for SARS-CoV-2 was 58% lower among influenza-positive cases and patients with a coinfection had a risk of death of 5.92 (95% confidence interval: 3.21-10.91) times greater than among those with neither influenza nor SARS-CoV-2. The odds of ventilator use or death and intensive care unit admission or death were greatest among coinfected patients.

Conclusions: Coinfection of these viruses could have a significant impact on morbidity, mortality and health-service demand.

Keywords: SARS-CoV-2; coinfection; epidemiology; influenza; interaction.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Distribution of SARS-CoV-2, influenza and coinfected cases in England from between 20 January 2020 and 25 April 2020 (Weeks 1–17)
Figure 2
Figure 2
The odds and 95% confidence intervals* of death, ventilator use and ICU admission by influenza/SARS-CoV-2 status compared with individuals with no infection in England from 20 January 2020 to 25 April 2020
See this image and copyright information in PMC

References

    1. Antony S, Almaghlouth N, Heydemann E.. Are co‐infections with COVID‐19 and Influenza low or underreported? An observational study examining current published literature including three new unpublished cases. J Med Virol 2020;92:2489–97. - PubMed
    1. Lansbury L, Lim B, Baskaran V, Lim WS.. Co-infections in people with COVID-19: a systematic review and meta-analysis. J Infect 2020;81:266–75. - PMC - PubMed
    1. Nickbakhsh S, Mair C, Matthews L. et al.Virus-virus interactions impact the population dynamics of influenza and the common cold. Proc Natl Acad Sci USA 2019;116:27142–50. - PMC - PubMed
    1. Cowling BJ, Fang VJ, Nishiura H. et al.Increased risk of noninfluenza respiratory virus infections associated with receipt of inactivated influenza vaccine. Clin Infect Dis 2012;54:1778–83. - PMC - PubMed
    1. Isaacs A, Burke DC.. Viral interference and interferon. Br Med Bull 1959;15:185–88. - PubMed

Publication types