SARS-CoV-2, influenza A/B and respiratory syncytial virus positivity and association with influenza-like illness and self-reported symptoms, over the 2022/23 winter season in the UK: a longitudinal surveillance cohort

Elisabeth Dietz; Emma Pritchard; Koen Pouwels; Muhammad Ehsaan; Joshua Blake; Charlotte Gaughan; Eric Haduli; Hugh Boothe; Karina-Doris Vihta; Tim Peto; Nicole Stoesser; Philippa Matthews; Nick Taylor; Ian Diamond; Ruth Studley; Emma Rourke; Paul Birrell; Daniela De Angelis; Tom Fowler; Conall Watson; David Eyre; Thomas House; Ann Sarah Walker

doi:10.1186/s12916-024-03351-w

SARS-CoV-2, influenza A/B and respiratory syncytial virus positivity and association with influenza-like illness and self-reported symptoms, over the 2022/23 winter season in the UK: a longitudinal surveillance cohort

BMC Med. 2024 Mar 26;22(1):143. doi: 10.1186/s12916-024-03351-w.

Authors

Elisabeth Dietz^{1

2}, Emma Pritchard^{3

4}, Koen Pouwels^{4

5}, Muhammad Ehsaan⁶, Joshua Blake⁷, Charlotte Gaughan⁸, Eric Haduli⁶, Hugh Boothe⁶, Karina-Doris Vihta⁹, Tim Peto^{3

4

10}, Nicole Stoesser^{3

4

10}, Philippa Matthews^{11

12}, Nick Taylor⁸, Ian Diamond⁸, Ruth Studley⁸, Emma Rourke⁸, Paul Birrell^{7

13}, Daniela De Angelis⁷, Tom Fowler^{13

14}, Conall Watson¹³, David Eyre^{4

15}, Thomas House¹⁶, Ann Sarah Walker^{3

4

17}

Affiliations

¹ Nuffield Department of Medicine, University of Oxford, Oxford, UK. Vilde.dietz@ndm.ox.ac.uk.
² The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK. Vilde.dietz@ndm.ox.ac.uk.
³ Nuffield Department of Medicine, University of Oxford, Oxford, UK.
⁴ The National Institute for Health Research Health Protection Research Unit in Healthcare Associated Infections and Antimicrobial Resistance at the University of Oxford, Oxford, UK.
⁵ Health Economics Research Centre, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
⁶ Berkshire and Surrey Pathology Services, Camberley, UK.
⁷ MRC Biostatistics Unit, University of Cambridge, Cambridge, UK.
⁸ Office for National Statistics, Newport, UK.
⁹ Department of Engineering, University of Oxford, Oxford, UK.
¹⁰ Department of Infectious Diseases and Microbiology, Oxford University Hospitals NHS Foundation Trust, John Radcliffe Hospital, Oxford, UK.
¹¹ The Francis Crick Institute, 1 Midland Road, London, UK.
¹² Division of Infection and Immunity, University College London, London, UK.
¹³ UK Health Security Agency, London, UK.
¹⁴ William Harvey Research Institute, Queen Mary University of London, London, UK.
¹⁵ Big Data Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
¹⁶ University of Manchester, Manchester, UK.
¹⁷ The National Institute for Health Research Oxford Biomedical Research Centre, University of Oxford, Oxford, UK.

Abstract

Background: Syndromic surveillance often relies on patients presenting to healthcare. Community cohorts, although more challenging to recruit, could provide additional population-wide insights, particularly with SARS-CoV-2 co-circulating with other respiratory viruses.

Methods: We estimated the positivity and incidence of SARS-CoV-2, influenza A/B, and RSV, and trends in self-reported symptoms including influenza-like illness (ILI), over the 2022/23 winter season in a broadly representative UK community cohort (COVID-19 Infection Survey), using negative-binomial generalised additive models. We estimated associations between test positivity and each of the symptoms and influenza vaccination, using adjusted logistic and multinomial models.

Results: Swabs taken at 32,937/1,352,979 (2.4%) assessments tested positive for SARS-CoV-2, 181/14,939 (1.2%) for RSV and 130/14,939 (0.9%) for influenza A/B, varying by age over time. Positivity and incidence peaks were earliest for RSV, then influenza A/B, then SARS-CoV-2, and were highest for RSV in the youngest and for SARS-CoV-2 in the oldest age groups. Many test positives did not report key symptoms: middle-aged participants were generally more symptomatic than older or younger participants, but still, only ~ 25% reported ILI-WHO and ~ 60% ILI-ECDC. Most symptomatic participants did not test positive for any of the three viruses. Influenza A/B-positivity was lower in participants reporting influenza vaccination in the current and previous seasons (odds ratio = 0.55 (95% CI 0.32, 0.95)) versus neither season.

Conclusions: Symptom profiles varied little by aetiology, making distinguishing SARS-CoV-2, influenza and RSV using symptoms challenging. Most symptoms were not explained by these viruses, indicating the importance of other pathogens in syndromic surveillance. Influenza vaccination was associated with lower rates of community influenza test positivity.

Keywords: Influenza a/b; Influenza-like illness; Respiratory syncytial virus; SARS-CoV-2; Surveillance; Symptoms; Vaccination.

MeSH terms

COVID-19*
Humans
Influenza, Human* / epidemiology
Middle Aged
Respiratory Syncytial Virus Infections* / epidemiology
Respiratory Syncytial Viruses
SARS-CoV-2
Seasons
Self Report
United Kingdom
Virus Diseases*