Performance Evaluation of Two Kinds of Rapid Antigen Test Kits for Detection of COVID-19 Infection.

BACKGROUND: The diagnostic standard for COVID-19 infection is real-time reverse transcription-polymerase chain reaction (rRT-PCR) of nasopharyngeal swab and oropharyngeal swab specimens. Rapid antigen tests are cheaper and easier to use than the rRT-PCR method. Although the COVID-19 pandemic is settling down, seasonal epi¬demic is expected. In this study, the performance of two rapid antigen test kits was evaluated based on rRT-PCR test results. METHODS: A total of 346 residual samples was tested by the PowerChek SARS-CoV-2 Real-time PCR Kit or STAN-DARD M nCoV Real-Time-Detection kit, STANDARD Q COVID-19 Ag test kit (SQ RAT), and ND COVID-19 Ag test kit (ND RAT). RESULTS: Compared to rRT-PCR as the standard method, the SQ RAT test kit yielded 77.1% sensitivity (101/131) and 100% specificity (215/215), and the ND RAT yielded 89.3% sensitivity (117/131) and 100% specificity (215/ 215). Both RATs showed sensitivity greater than 85% in samples with RdRp gene Ct value less than 25. There was a false-negative case suspected of prozone phenomenon. CONCLUSIONS: Both RATs showed significant performance, but users should beware of the prozone phenomenon.

Quality improvement of outpatient clinical chemistry tests through a novel middleware-laboratory information system solution.

OBJECTIVES: Rapid and accurate laboratory tests are essential to support clinical decision-making. Despite the various efforts to control quality in the laboratory, our outpatient chemistry turnaround time (TAT) has deteriorated since 2018. Moreover, these difficulties have accelerated further due to the COVID-19 pandemic. Therefore, we aimed to improve laboratory work efficiency by identifying and eliminating the causes of reduced laboratory work efficiency. DESIGN & METHODS: We surveyed to identify tasks that reduce work efficiency. Based on our survey, a new-concept of work assistance middleware linked to laboratory information system (LIS) was developed. The middleware supports test end-time prediction, automatic real-time TAT monitoring, and urgent test requests so that medical technologists can focus on their chemistry tests. The developed middleware was used for 6 months in laboratory and outpatient clinics, and its effectiveness was evaluated. RESULTS: The median TAT for outpatient chemistry tests was reduced by 6.6 min, from 72.4 min to 65.8 min. And not only did the maximum TAT for the sample decrease from 353 min to 214 min, but the proportion of samples exceeding the TAT target (120 min) also decreased by 77%; from 2.00% in 2010 (1,905 out of 94,989 samples) to 0.46% in 2021 (453 out of 98,117 samples). 2,199 samples were urgently requested through middleware, and they were processed about 15% faster than other samples, effectively performing urgent tests. The test end-time prediction showed an error of 8.6 min in the evaluation using the MAE (Mean Absolute Error) index. CONCLUSIONS: Through this study, the quality and efficiency of the laboratory were improved, and while reducing the workload of medical staff, it contributed to enhancing patient safety and satisfaction.

Comparison of ACCEL ELISA COVID-19 with Elecsys Anti-SARS-CoV-2 for Screening of COVID-19.

OBJECTIVE: Although real-time reverse transcription-PCR (RT-PCR) is the gold standard for diagnosing coronavirus disease 2019 (COVID-19), simpler and faster antibody detection tests can be complementary for diagnosis of COVID-19. To manage the COVID-19 pandemic, the need for serologic testing has increased. In this report, the newly developed antibody detection assays ACCEL ELISA COVID-19 (ACCEL) and Elecsys anti-SARS-CoV-2 (Elecsys) were evaluated. METHODS: Serum samples submitted for routine laboratory testing were analyzed (66 and 161 PCR-positive and PCR-negative samples). After the samples were aliquoted, antibody detection tests were performed using ACCEL and Elecsys assays. RESULTS: When detection of viral RNA using RT-PCR was set as the reference method for diagnosis of COVID-19, the sensitivity was 83.3% and 75.8, and the specificity was 96.9 and 99.4% in ACCEL and Elecsys, respectively. The true positivity rates of ACCEL and Elecsys assays were 57.1%/42.9%, 57.1%/28.6%, 77.8%/66.7%, and 97.1%/97.1% among the specimens collected ≤3, 4-7, 8-14, and >14 days after symptom onset, respectively. CONCLUSIONS: The ACCEL assay showed high sensitivity in samples collected within 7 days after symptom onset. Because many patients are asymptomatic in the early stage of SARS-CoV-2 infection, the ACCEL assay could be a good screening tool due to high sensitivity in the early stage of SARS-CoV-2 infection.