The aim of our study was to evaluate the diagnostic performance of two antigen rapid diagnostic tests (Ag‐RDTs) to diagnose severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection. We ...evaluated Panbio and SD‐Biosensor Ag‐RDTs. We employed 186 polymerase chain reaction (PCR) negative samples to evaluate the specificity and 170 PCR positive samples to assess the sensitivity. We evaluated their sensitivity according to Cycle threshold (C
t) values and days post onset of symptoms (d.p.o.). Tests were compared using the McNemar's test. Agreement was evaluated using the kappa score. Specificity was 100% for Panbio and 97.3% for SD‐Biosensor. Sensitivity for samples with C
t ≤ 20 was 100% for both assays and for samples with C
t = 20–25 was 93.0% (Panbio) and 95.3% (SD‐Biosensor) (p = 1.000). Sensitivity decreased for samples wit C
t = 25–30 (Panbio: 41.3%, SD‐Biosensor: 52.2%, p = 0.125) and samples with C
t ≥ 30 (Panbio: 5.0%, SD‐Biosensor: 17.5%, p = 0.063). Sensitivity within seven d.p.o. was 87.7% for Panbio and 90.4% for SD‐Biosensor and notably decreased after seven d.p.o. Agreement with PCR was excellent for high viral load samples (C
t ≤ 25): Panbio, 98.9%, kappa = 0.974; SD‐Biosensor, 97.4%, kappa = 0.940. Agreement between Ag‐RDTs was excellent (94.9%, kappa = 0.882). Panbio and SD‐Biosensor Ag‐RDTs showed excellent agreement and diagnostic performance results for samples with high viral loads (C
t ≤ 25) or samples within seven d.p.o.
Highlights
Panbio and SD‐Biosensor Ag‐RDTs are reliable to diagnose SARS‐CoV‐2 infection.
They showed high specificity: 100% (Panbio) and 97.3% (SD‐Biosensor).
Sensitivity for samples with Ct ≤ 20 was 100% and for samples with Ct ≤ 25 was over 93%.
Their sensitivity was over 87% within 7 days after symptoms onset. Agreement between them was excellent (agreement = 94.9%, kappa = 0.882).
•CerTest and Panbio Ag-RDTs are reliable to diagnose SARS-CoV-2 infection.•Their sensitivity was over 90 % for samples with a Ct≤25.•Their sensitivity was over 84 % within 5 days after the onset of ...symptoms.•Specificity of both assays was 100 %. Agreement between them was excellent.•Agreement with PCR was also excellent for samples with Ct≤25.
Antigen rapid diagnostic tests (Ag-RDT) have been developed as reliable tools to control the SARS-CoV-2 pandemic. The objective of our study was to evaluate the diagnostic performance of two Ag-RDTs.
We evaluated CerTest SARS-CoV-2 Ag One Step Card Test and Panbio COVID-19 Ag Rapid Test Device Ag-RDTs. We included 320 nasopharyngeal samples: 150 PCR negative samples to assess the specificity and 170 PCR positive samples to evaluate the sensitivity. We also evaluated their sensitivity according to cycle threshold (Ct) values and the time from the onset of symptoms. Tests were compared using the McNemar’s test and agreement was evaluated using the kappa score (k).
Both Ag-RDTs showed a specificity of 100 %. Overall sensitivity was 53.5 % for CerTest and 60.0 % for Panbio. For samples with Ct≤ 25, sensitivity was 94.0 % for CerTest and 96.4 % for Panbio (p = 0.500). Regarding samples with Ct>25, sensitivity was 14.0 % for CerTest and 24.4 % for Panbio (p = 0.004). Sensitivity for samples within the first 5 days after the onset of symptoms were 84.8 % for CerTest and 91.3 % for Panbio (p = 0.250) and notably decreased for samples taken after the fifth day. Both Ag-RDTs showed an excellent agreement between them (agreement = 96.7 %, k = 0.920). Agreement with PCR was also excellent for high viral load samples (Ct<25) for CerTest (98.0 %, k = 0.954) and Panbio (98.8 %, k = 0.973).
CerTest SARS-CoV-2 and Panbio COVID-19 Ag showed excellent performance and agreement results for samples with high viral loads (Ct ≤ 25) or samples taken within the first 5 days after the onset of symptoms.
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