Table 1.
Characteristics and performance of four rapid SARS-CoV-2 antigen-detection tests.
| Characteristics | Test N°1 | Test N°2 | Test N°3 | Test N°4 |
|---|---|---|---|---|
| Commercial name | Biocredit One Step SARS-CoV-2 Antigen Test | StrongStep® COVID-19 Antigen Test | Huaketai New Coronavirus (SARS-CoV-2) N Protein Detection Kit (FIA) | Diagnostic Kit for 2019-Novel Coronavirus (2019-nCoV) Ag Test (FIA) |
| Manufacturer | RapiGen Inc., Anyang-si, Gyeonggi-do, Rep. of Korea | Liming Bio-Products Co., Jiangsu, China | Savant Biotechnology Co., Beijing, China | Bioeasy Biotechnology Co., Shenzhen, China |
| Catalogue N° (lot N°) | G61RHA20 (H073001SD) | 500200 (2003014) | BCT-HKT-050 (20031501) | YRLF04401025 (2002N408) |
| Certificationa | CE-IVD | CE-IVD | CE-IVD | CE-IVD |
| Primary specimenb | NP/OP swab | NP/OP swab | Throat swab | NP/OP swab, sputum |
| Incubation (ambient)b | 5–8 minutes | 15–20 minutes | 15 minutes ± 1 minute | 10 minutes ± 0 minutes |
| Readoutb |
Visual: coloured bands |
Visual: coloured bands |
Visual: fluorescent bandsc |
Automated: fluorescence reader |
|
Performanced | ||||
| Sample size (n) | 109e | 19f | 109e | 111 |
| Sensitivity | 62% (49/79) CI95% 51–71.9 |
0% (0/9) CI95% 0–29.9 |
16.7 (13/78) CI95% 10–16.5 |
85% (68/80) 75.6–91.2 |
| Specificity | 100% (30/30) CI95% 88.7–100 |
90% (9/10) CI95% 59.6–98.2 |
100% (31/31) CI95% 89-100 |
100% (31/31) CI95% 89-100 |
| Accuracy | 72.5% | 47.4% | 40.4% | 89.2% |
| Kappa coefficient | 0.5 | −0.1 | 0.1 | 0.8 |
| Sensitivity, high VLg | 84.9% (45/53) CI95% 72.9–92.1 |
NA | 21.2% (11/52) CI95% 12.2–34 |
100% (54/54) CI95% 93.4–100 |
| Sensitivity, low VLh | 15.4% (4/26) CI95% 17.5–37.7 |
NA | 7.7% (2/26) CI95% 2.1–24.1 |
53.8% (14/26) CI95% 25.5–37.4 |
| Mean Ct of false negatives (range) | 29.6 (17.5–37.7) | NA | 21.9 (10.7–37.7) | 34.4 (25.5–37.4) |
FIA, fluorescence immune assay; NP, nasopharyngeal; OP, oropharyngeal; UTM, universal transport medium.
a
According to https://www.finddx.org/covid-19/pipeline.
b
According to manufacturer's recommendation.
c
Using UV flashlight recommended and provided by manufacturer.
d
Study protocol included deviation from manufacturer's instructions (see text).
e
Two invalid results were excluded.
f
Testing was suspended after 19 samples due to poor test performance.
g
Samples with high viral loads (Ct ≤ 25).
h
Samples with low viral loads (Ct > 25).