Interactions between SARS-CoV-2 and influenza, and the impact of coinfection on disease severity: a test-negative design. (3rd May 2021)

• Record Type: Journal Article
• Authors: Stowe, Julia; Tessier, Elise; Zhao, H; Guy, Rebecca; Muller-Pebody, Berit; Zambon, Maria; Andrews, Nick; Ramsay, Mary; Lopez Bernal, Jamie
• Is Part Of: International journal of epidemiology. Volume 50:Number 4(2021)
• Page Start: 1124
• Page End: 1133
• Publication Date: 2021-05-03
• Subjects: SARS-CoV-2 -- influenza -- coinfection -- interaction -- epidemiology; Epidemiology -- Periodicals; 614.4
• DOI: 10.1093/ije/dyab081
• Languages: English
• ISSNs: 0300-5771

Abstract

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.