Multiplex lateral flow test sensitivity and specificity in detecting influenza A, B and SARS-CoV-2 in adult patients in a UK emergency department

Authors

• Rahul Batra, St Thomas' Hospital
• Edward Blandford, Science Group, UK Health Security Agency, London, UK.
• Raghavendran Kulasegaran-Shylini, Science Group, UK Health Security Agency, London, UK.
• Matthias E Futschik, School of Biomedical Sciences
• Abbie Bown, UK Health Security Agency Porton, Salisbury, UK.
• Matthew Catton, UK Health Security Agency Porton, Salisbury, UK.
• Hermione Conti-Frith, UK Health Security Agency Porton, Salisbury, UK.
• Alexandra Alexandridou, UK Health Security Agency Porton, Salisbury, UK.
• Rebecca Gill, UK Health Security Agency Porton, Salisbury, UK.
• Clara Milroy, UK Health Security Agency Porton, Salisbury, UK.
• Sean Harper, Science Group, UK Health Security Agency, London, UK.
• Holly Gettings, Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK.
• Maryann Noronha, Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK.
• Hooi-Ling Harrison, Emergency Department, Guy's and St Thomas' NHS Foundation Trust, London, UK.
• Sam Douthwaite, Department of Infectious Diseases, Guy's and St Thomas' NHS Foundation Trust, London, UK.
• Gaia Nebbia, Department of Infectious Diseases, Guy's and St Thomas' NHS Foundation Trust, London, UK.
• Paul E Klapper, Science Group, UK Health Security Agency, London, UK.
• Sarah Tunkel, Science Group, UK Health Security Agency, London, UK.
• Richard Vipond, UK Health Security Agency Porton, Salisbury, UK.
• Susan Hopkins, Science Group, UK Health Security Agency, London, UK.
• Tom Fowler, Science Group, UK Health Security Agency, London, UK.

ORCID

• Matthias E Futschik: 0000-0002-6245-8071

Abstract

BACKGROUND: Rapid identification of individuals with acute respiratory infections is crucial for preventing nosocomial infections. For rapid diagnosis, especially in EDs, lateral flow devices (LFDs) are a convenient, inexpensive option with a rapid turnaround. Several 'multiplex' LFDs (M-LFDs) now exist, testing for multiple pathogens from a single swab sample. We evaluated the real-world performance of M-LFD versus PCR testing in detecting influenza A, B and SARS-CoV-2) in the ED setting.

METHODS: After preliminary evaluation of an M-LFD (SureScreen) with laboratory-grown virus and PCR-negative clinical samples, it was evaluated in a real-world setting at the ED of St Thomas' Hospital (London, UK) from 1 December 2022 to 21 April 2023. Eligible participants were ≥18 years of age, admitted with respiratory symptoms and received concurrent M-LFD and PCR tests. Main endpoints were sensitivity to detect influenza A/B (primary) and SARS-CoV-2 (secondary) versus PCR. The probability of a true positive in relation to viral concentration (expressed as PCR cycle threshold (Ct)) was analysed using logistic regression.

RESULTS: In total, 808 symptomatic participants were included (49.8% female; mean age 46.9 years). Test sensitivity (95% CI) was 67.0% (56.9% to 76.1%) for influenza A (n=100), 94.1% (71.3% to 99.9%) for influenza B (n=17) and 48.2% (39.7% to 56.8%) for SARS-CoV-2 (n=141). Sensitivity for SARS-CoV-2 was significantly lower than that for influenza A and B (p=0.0057 and p=0.00088, respectively). The probability of a true positive was 98% for Ct<25 for influenza A and SARS-CoV-2 (influenza B non-evaluable). No co-infections were identified by PCR or M-LFD.

CONCLUSION: The real-world performance of SureScreen M-LFD was consistent with laboratory evaluation and achieved a high sensitivity for individuals with high viral concentration, most likely to be infectious. Given the representative UK population sample, results could be generalised for use in other settings.

DOI Link

10.1136/emermed-2024-214177

Publication Date

2025-01-01

Publication Title

Emerg Med J

Volume

42

Issue

2

Acceptance Date

2024-11-07

Deposit Date

2026-04-20

Keywords

Humans, Influenza, Human/diagnosis, Female, Emergency Service, Hospital/organization & administration, Male, Sensitivity and Specificity, Middle Aged, COVID-19/diagnosis, SARS-CoV-2/isolation & purification, United Kingdom, Adult, Influenza B virus/isolation & purification, Influenza A virus/isolation & purification, Aged

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License

First Page

98

Last Page

104

Recommended Citation

Batra, R., Blandford, E., Kulasegaran-Shylini, R., Futschik, M., Bown, A., Catton, M., Conti-Frith, H., Alexandridou, A., Gill, R., Milroy, C., Harper, S., Gettings, H., Noronha, M., Harrison, H., Douthwaite, S., Nebbia, G., Klapper, P., Tunkel, S., Vipond, R., Hopkins, S., & Fowler, T. (2025) 'Multiplex lateral flow test sensitivity and specificity in detecting influenza A, B and SARS-CoV-2 in adult patients in a UK emergency department', Emerg Med J, 42(2), pp. 98-104. Available at: 10.1136/emermed-2024-214177