2021 Volume 70 Issue 3 Pages 403-409
Purpose: To date, numerous test reagents for the detection of SARS-CoV-2 have been released in the market in Japan. However, few reports regarding the performance of these reagents have been published. In this paper, we aim to evaluate the performance of two reagents, “μTASWako COVID-19” (“μTAS”) and “SARS-CoV-2 Direct Detection RT-qPCR Kit” (“SARS-CoV-2 kit”). Method: A nasopharyngeal swab was used as the sample, and “μTAS” and “SARS-CoV-2 kit” were compared by the following methods: ① comparison of match rate of results, ② comparison of various conditions between the positive-match group and the result-mismatch group, and ③ comparison of Ct values. Result: ① The positive match rate was 58% (15/26), whereas the negative match rate was 100% (13/13). The overall match rate was 72% (28/39). ② A significant difference was observed in the number of days of onset at the time of sample collection (p = 0.002). ③ The median difference in Ct values was 6.5, indicating that the measured Ct value for “μTAS” was significantly higher (p < 0.001). Conclusion: The results suggests that “μTAS” seems to be less sensitive than “SARS-CoV-2 kit”. Therefore, clinicians should carefully consider false negatives in the screening test when using “μTAS”. In addition, when infectiousness is estimated with reference to the Ct value, “μTAS” may provide a higher Ct value than other methods.
