tetano
Editor, Senior Moderator
J Infect Chemother
. 2021 Jul 13;S1341-321X(21)00189-6.
doi: 10.1016/j.jiac.2021.07.006. Online ahead of print.
The evaluation of a novel digital immunochromatographic assay with silver amplification to detect SARS-CoV-2
Yoko Kurihara[SUP] 1 [/SUP], Yoshihiko Kiyasu[SUP] 2 [/SUP], Yusaku Akashi[SUP] 3 [/SUP], Yuto Takeuchi[SUP] 1 [/SUP], Kenji Narahara[SUP] 4 [/SUP], Sunao Mori[SUP] 4 [/SUP], Tomonori Takeshige[SUP] 4 [/SUP], Shigeyuki Notake[SUP] 5 [/SUP], Atsuo Ueda[SUP] 5 [/SUP], Koji Nakamura[SUP] 5 [/SUP], Hiroichi Ishikawa[SUP] 6 [/SUP], Hiromichi Suzuki[SUP] 7 [/SUP]
Affiliations
Abstract
Introduction: Rapid antigen tests are convenient for diagnosing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, they have lower sensitivities than nucleic acid amplification tests. In this study, we evaluated the diagnostic performance of Quick Chaser[SUB]®[/SUB] Auto SARS-CoV-2, a novel digital immunochromatographic assay that is expected to have higher sensitivity than conventional antigen tests.
Methods: A prospective observational study was conducted between February 8 and March 24, 2021. We simultaneously obtained two nasopharyngeal samples, one for evaluation with the QuickChaser[SUB]®[/SUB] Auto SARS-CoV-2 antigen test and the other for assessment with reverse transcription PCR (RT-PCR), considered the gold-standard reference test. The limit of detection (LOD) of the new antigen test was compared with those of four other commercially available rapid antigen tests.
Results: A total of 1401 samples were analyzed. SARS-CoV-2 was detected by reference RT-PCR in 83 (5.9%) samples, of which 36 (43.4%) were collected from symptomatic patients. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.7% (95% confidence interval (CI): 64.0-83.6%), 99.8% (95% CI: 99.5-100%), 96.9% (95% CI: 89.2-99.6%), and 98.4% (95% CI: 97.6-99.0%), respectively. When limited to samples with a cycle threshold (Ct) < 30 or those from symptomatic patients, the sensitivity increased to 98.3% and 88.9%, respectively. The QuickChaser[SUB]®[/SUB] Auto SARS-CoV-2 detected 34-120 copies/test, which indicated greater sensitivity than the other rapid antigen tests.
Conclusions: QuickChaser[SUB]®[/SUB] Auto SARS-CoV-2 showed sufficient sensitivity and specificity in clinical samples of symptomatic patients. The sensitivity was comparable to RT-PCR in samples with Ct < 30.
Keywords: COVID-19; Digital immuno-chromatographic antigen test; FUJI DRI-CHEM; QuickChaser Auto; SARS-CoV-2; Silver amplification.
. 2021 Jul 13;S1341-321X(21)00189-6.
doi: 10.1016/j.jiac.2021.07.006. Online ahead of print.
The evaluation of a novel digital immunochromatographic assay with silver amplification to detect SARS-CoV-2
Yoko Kurihara[SUP] 1 [/SUP], Yoshihiko Kiyasu[SUP] 2 [/SUP], Yusaku Akashi[SUP] 3 [/SUP], Yuto Takeuchi[SUP] 1 [/SUP], Kenji Narahara[SUP] 4 [/SUP], Sunao Mori[SUP] 4 [/SUP], Tomonori Takeshige[SUP] 4 [/SUP], Shigeyuki Notake[SUP] 5 [/SUP], Atsuo Ueda[SUP] 5 [/SUP], Koji Nakamura[SUP] 5 [/SUP], Hiroichi Ishikawa[SUP] 6 [/SUP], Hiromichi Suzuki[SUP] 7 [/SUP]
Affiliations
- PMID: 34294528
- DOI: 10.1016/j.jiac.2021.07.006
Abstract
Introduction: Rapid antigen tests are convenient for diagnosing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); however, they have lower sensitivities than nucleic acid amplification tests. In this study, we evaluated the diagnostic performance of Quick Chaser[SUB]®[/SUB] Auto SARS-CoV-2, a novel digital immunochromatographic assay that is expected to have higher sensitivity than conventional antigen tests.
Methods: A prospective observational study was conducted between February 8 and March 24, 2021. We simultaneously obtained two nasopharyngeal samples, one for evaluation with the QuickChaser[SUB]®[/SUB] Auto SARS-CoV-2 antigen test and the other for assessment with reverse transcription PCR (RT-PCR), considered the gold-standard reference test. The limit of detection (LOD) of the new antigen test was compared with those of four other commercially available rapid antigen tests.
Results: A total of 1401 samples were analyzed. SARS-CoV-2 was detected by reference RT-PCR in 83 (5.9%) samples, of which 36 (43.4%) were collected from symptomatic patients. The sensitivity, specificity, positive predictive value, and negative predictive value were 74.7% (95% confidence interval (CI): 64.0-83.6%), 99.8% (95% CI: 99.5-100%), 96.9% (95% CI: 89.2-99.6%), and 98.4% (95% CI: 97.6-99.0%), respectively. When limited to samples with a cycle threshold (Ct) < 30 or those from symptomatic patients, the sensitivity increased to 98.3% and 88.9%, respectively. The QuickChaser[SUB]®[/SUB] Auto SARS-CoV-2 detected 34-120 copies/test, which indicated greater sensitivity than the other rapid antigen tests.
Conclusions: QuickChaser[SUB]®[/SUB] Auto SARS-CoV-2 showed sufficient sensitivity and specificity in clinical samples of symptomatic patients. The sensitivity was comparable to RT-PCR in samples with Ct < 30.
Keywords: COVID-19; Digital immuno-chromatographic antigen test; FUJI DRI-CHEM; QuickChaser Auto; SARS-CoV-2; Silver amplification.