Clinical evaluation of SARS-CoV-2 rapid antigen tests during the Omicron wave in South Africa

Authors: Samsunder N, de Vos M, Ngcapu S, Giandhari J, Lewis L, Kharsany AB, Carwood C, de Oliveira T, Karim QA, Karim SA, Naidoo K, Escadafal C, Sivro A

Journal: J Infect Dis., 2022. DOI:

Abstract

We evaluated the performance of nasal and nasopharyngeal Standard Q COVID-19 Ag tests (SD Biosensor) and the Panbio COVID-19 Ag Rapid Test Device (nasal, Abbott) against the Abbott RealTime SARS-CoV-2 assay during the Omicron (21 M, 21K and 21L) wave in South Africa. Overall, all evaluated tests performed well with high level of sensitivity (ranging from 77.78-81.42%) and excellent specificity values (>99%). The sensitivity of rapid antigen tests increased above 90% in samples with Ct <20, and all three tests performed best within first week of symptom onset. The Panbio Ag test performed best in the context of Omicron 21L infections, that were also characterised by significantly lower Ct values compared to infections with 21K and 21 M.

Manuscripts: