A Prospective Evaluation of the Analytical Performance of GENECUBE® HQ SARS-CoV-2 and GENECUBE® FLU A/B

Takeuchi

et al. 2021

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Introduction: Antigen testing may help screen for and detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in asymptomatic individuals. However, limited data regarding the diagnostic performance of antigen tests for this group are available. Methods: We used clinical samples to prospectively evaluate the analytical and clinical performance of the antigen test QuickNavi™-COVID19 Ag. This study was conducted at a PCR center between October 7, 2020 and January 9, 2021. Two nasopharyngeal samples per patient were obtained with flocked swabs; one was used for the antigen test, and the other for real-time reverse transcription PCR (RT-PCR). The diagnostic performance of the antigen test was compared between asymptomatic and symptomatic patients, and the RT-PCR results were used as a reference. Results: Among the 1934 collected samples, 188 (9.7%) demonstrated detection of SARS-CoV-2 by real-time RT-PCR; 76 (40.4%) of these 188 samples were from asymptomatic individuals, and over half of the total samples were asymptomatic (1073; 55.5%). The sensitivity of the antigen test was significantly lower for the asymptomatic group than for symptomatic patients (67.1% vs. 89.3%, respectively, p < 0.001). The specificity was 100% for both groups, and no false positives were observed among all 1934 samples. The median cycle threshold value for the asymptomatic group was significantly higher than that of the symptomatic group (24 vs. 20, p < 0.001). Conclusions: The QuickNavi™-COVID19 Ag showed lower sensitivity for the asymptomatic group than for symptomatic patients. However, its specificity was consistently high, and no false positives were found in this study.

Section: Pcr Examinations For Sars-cov-2mentioning

confidence: 99%

Prospective analytical performance evaluation of the QuickNavi™-COVID19 Ag for asymptomatic individuals

Takeuchi

et al. 2021

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“…magLEAD 6gC (Precision System Science, Chiba, Japan) was used for extraction and purification of RNA from UTM™ samples. GENECUBE and GENECUBE ® HQ SARS-CoV-2 were used for in-house RT-PCR [9]. The purified samples were then transferred to Mizuho Medy for reference real-time RT-PCR.…”

Section: Rt-pcr Assay For Sars-cov-2mentioning

confidence: 99%

The evaluation of a novel digital immunochromatographic assay with silver amplification to detect SARS-CoV-2

Kurihara

et al. 2021

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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 ® 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 ® 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 ® Auto SARS-CoV-2 detected 34–120 copies/test, which indicated greater sensitivity than the other rapid antigen tests. Conclusions QuickChaser ® 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.

“…In this study, we enrolled participants and collected samples at the PCR center in Tsukuba Medical Center Hospital (TMCH) between March 25 and July 5, 2021, which intensively collected nasopharyngeal samples for the PCR analysis of SARS-CoV-2 [ [5] , [6] , [7] , [8] , [9] ]. Subjects referred by 59 primary care facilities and a local public health center, as well as TMCH healthcare workers with suspected SARS-CoV-2 infection based on symptoms or a known contact history with COVID-19 confirmed/suspected patients were prospectively enrolled.…”

Section: Methodsmentioning

confidence: 99%

“…Purification and RNA extraction from UTM™ samples were performed with magLEAD® 6gC (Precision System Science, Chiba, Japan). The purified samples were evaluated by GENECUBE® and GENECUBE® HQ SARS-CoV-2 as an in-house RT-PCR assay [ 8 ].…”

Section: Methodsmentioning

confidence: 99%

Clinical evaluation of the rapid nucleic acid amplification point-of-care test (Smart Gene SARS-CoV-2) in the analysis of nasopharyngeal and anterior nasal samples

Owaku

et al. 2022

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Introduction Smart Gene is a point-of-care (POC)-type automated molecular testing platform that can be performed with 1 min minute of hands-on-time. Smart Gene SARS-CoV-2 is a newly developed Smart Gene molecular assay for the detection of SARS-CoV-2. The analytical and clinical performance of Smart Gene SARS-CoV-2 has not been evaluated. Methods Nasopharyngeal and anterior nasal samples were prospectively collected from subjects referred to the local PCR center from March 25 to July 5, 2021. Two swabs were simultaneously obtained for the Smart Gene SARS-CoV-2 assay and the reference real-time RT-PCR assay, and the results of Smart Gene SARS-CoV-2 were compared to the reference real-time RT-PCR assay. Results Among a total of 1150 samples, 68 of 791 nasopharyngeal samples and 51 of 359 anterior nasal samples were positive for SARS-CoV-2 in the reference real-time RT-PCR assay. In the testing of nasopharyngeal samples, Smart Gene SARS-CoV-2 showed the total, positive and negative concordance of 99.2% (95% confidence interval [CI]: 98.4–99.7%), 94.1% (95% CI: 85.6–98.4%) and 99.7% (95% CI: 99.0–100%), respectively. For anterior nasal samples, Smart Gene SARS-CoV-2 showed the total, positive and negative concordance of 98.9% (95% CI: 97.2–99.7%), 98.0% (95% CI: 89.6–100%) and 99.0% (95% CI: 97.2–99.8%), respectively. In total, 5 samples were positive in the reference real-time RT-PCR assay and negative in the Smart Gene SARS-CoV-2 assay, whereas 5 samples were negative in the reference real-time RT-PCR assay and positive in the Smart Gene SARS-CoV-2 assay. Conclusion Smart Gene SARS-CoV-2 showed sufficient analytical performance for the detection of SARS-CoV-2 in nasopharyngeal and anterior nasal samples.