TY - JOUR

T1 - Accuracy of anterior nasal swab rapid antigen tests compared with RT-PCR for massive SARS-CoV-2 screening in low prevalence population

AU - Jakobsen, Kathrine Kronberg

AU - Jensen, Jakob Schmidt

AU - Todsen, Tobias

AU - Kirkby, Nikolai

AU - Lippert, Freddy

AU - Vangsted, Anne Marie

AU - Klokker, Mads

AU - von Buchwald, Christian

N1 - Funding Information: We thank Copenhagen Medical A/S for delivering the rapid Ag tests and providing test personnel for performing the tests. Publisher Copyright: © 2021 Scandinavian Societies for Medical Microbiology and Pathology

PY - 2022/2

Y1 - 2022/2

N2 - The aim was to determine the accuracy of anterior nasal swab in rapid antigen (Ag) tests in a low SARS-CoV-2 prevalence and massive screened community. Individuals, aged 18 years or older, who self-booked an appointment for real-time reverse transcriptase-polymerase chain reaction (RT-PCR) test in March 2021 at a public test center in Copenhagen, Denmark were included. An oropharyngeal swab was collected for RT-PCR testing, followed by a swab from the anterior parts of the nose examined by Ag test (SD Biosensor). Accuracy of the Ag test was calculated with RT-PCR as reference. We included 7074 paired conclusive tests (n = 3461, female: 50.7%). The median age was 48 years (IQR: 36–57 years). The prevalence was 0.9%, that is, 66 tests were positive on RT-PCR. Thirty-two had a paired positive Ag test. The sensitivity was 48.5% and the specificity was 100%. This study conducted in a low prevalence setting in a massive screening set-up showed that the Ag test had a sensitivity of 48.5% and a specificity of 100%, that is, no false positive tests. The lower sensitivity is a challenge especially if Ag testing is not repeated frequently allowing this scalable test to be a robust supplement to RT-PCR testing in an ambitious public SARS-CoV-2 screening.

AB - The aim was to determine the accuracy of anterior nasal swab in rapid antigen (Ag) tests in a low SARS-CoV-2 prevalence and massive screened community. Individuals, aged 18 years or older, who self-booked an appointment for real-time reverse transcriptase-polymerase chain reaction (RT-PCR) test in March 2021 at a public test center in Copenhagen, Denmark were included. An oropharyngeal swab was collected for RT-PCR testing, followed by a swab from the anterior parts of the nose examined by Ag test (SD Biosensor). Accuracy of the Ag test was calculated with RT-PCR as reference. We included 7074 paired conclusive tests (n = 3461, female: 50.7%). The median age was 48 years (IQR: 36–57 years). The prevalence was 0.9%, that is, 66 tests were positive on RT-PCR. Thirty-two had a paired positive Ag test. The sensitivity was 48.5% and the specificity was 100%. This study conducted in a low prevalence setting in a massive screening set-up showed that the Ag test had a sensitivity of 48.5% and a specificity of 100%, that is, no false positive tests. The lower sensitivity is a challenge especially if Ag testing is not repeated frequently allowing this scalable test to be a robust supplement to RT-PCR testing in an ambitious public SARS-CoV-2 screening.

U2 - 10.1111/apm.13189

DO - 10.1111/apm.13189

M3 - Journal article

C2 - 34758150

AN - SCOPUS:85120568507

VL - 130

SP - 95

EP - 100

JO - A P M I S. Acta Pathologica, Microbiologica et Immunologica Scandinavica

JF - A P M I S. Acta Pathologica, Microbiologica et Immunologica Scandinavica

SN - 0903-4641

IS - 2

ER -