Diagnostic Performance of Six Rapid Antigen Tests for SARS-CoV-2

Abstract

Microbiological diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been a challenge. Although real-time reverse transcription PCR (RT-PCR) represents the gold standard method, strategies that allow rapid and simple diagnosis are necessary for the early identification of cases. In this study, we evaluated the diagnostic performance of six different commercial rapid antigen tests (Coronavirus antigen [Ag] rapid test cassette [Healgen Scientific, Houston, TX, USA], COVID-19 Ag FIA [Vircell, SD Biosensor Inc., Gyeonggi-do, Republic of Korea], Clinitest rapid COVID-19 antigen test [Siemens, Healthineers, Erlangen, Germany], SARS-CoV-2 rapid antigen test [SD Biosensor; Roche Diagnostics, Basel, Switzerland], Panbio COVID-19 Ag rapid test device [Abbott, Chicago, IL, USA], and SARS-CoV-2 test [MonLab, Barcelona, Spain]) in 130 nasopharyngeal swab samples tested previously by RT-PCR. The overall sensitivity of the rapid tests ranged from 65% to 79%, and the specificity was 100% for all of them. The sensitivity was higher for those samples with RT-PCR cycle threshold (C_T) values below 25 and those from patients presenting within the first week of symptoms. The Siemens test showed the highest sensitivity for patients with high viral loads while the Vircell test performed better than the rest for C_T values of ≥25. IMPORTANCE The rapid detection of people infected with SARS-CoV-2 is essential for a correct and effective control of the disease it causes. This process must be sensitive, fast, and simple, and it must be possible to carry out in any type of health center. Rapid antigen tests are the answer to this need. Knowing its ability to detect the virus in different stages of the disease is essential for a correct diagnosis, which is why this study has been carried out to evaluate the sensitivity and specificity of 6 different antigens tests in nasopharyngeal smear samples.

Keywords: SARS-CoV-2; diagnosis; rapid antigen test.

FIG 1

Diagnostic performance of the rapid antigen tests evaluated in this study. (A) The overall sensitivity and specificity obtained for each test are represented in the forest plots. The dotted line indicates the mean of the sensitivity and specificity of all rapid antigen test evaluated. (B) Sensitivity was also calculated in ranges of C_T (<25 and ≥25) and days of onset (≤7 and >7). All values were calculated with a confidence interval (CI) of 95%.