Lateral flow devices maintain detection sensitivity across Alpha, Delta, and Omicron waves
3 Apr, 2023 | 13:53h | UTCSummary: The study assessed the performance of antigen lateral flow devices (LFDs) during the alpha, delta, and omicron waves of the SARS-CoV-2 pandemic in the UK. Researchers aimed to understand LFD performance concerning changes in variant infections, vaccination, viral load, and LFD use, as well as the devices’ ability to detect infectious individuals. Paired LFD and RT-PCR test results were collected from both asymptomatic and symptomatic participants between November 2020 and March 2022.
When compared to RT-PCR testing, the overall LFD sensitivity was 63.2%, and specificity was 99.71%. The sensitivity was higher in symptomatic participants (68.7%) than in asymptomatic participants (52.8%). The study found that increased viral load was independently associated with a higher likelihood of being LFD positive. There was no evidence of a significant difference in LFD sensitivity between the alpha and delta variants, but sensitivity increased during the omicron wave. Vaccination status did not show an independent association with LFD sensitivity.
The study concluded that LFDs can detect most SARS-CoV-2 infections across different viral variants and during vaccine roll-out, contributing to reduced transmission risk. However, LFD performance is lower in asymptomatic individuals, which should be taken into account when designing testing programs.
Invited Commentary: The performance of rapid antigen tests against SARS-CoV-2 variants – The Lancet Infectious Diseases
Related:
Interpreting a lateral flow SARS-CoV-2 antigen test – The BMJ