[Evaluation of fast nucleic acid detection system in severe acute respiratory syndrome coronavirus 2]

Objective: To evaluate the performance and application of a fast nucleic acid detection system for testing severe acute respiratory syndrome virus 2 (SARS-COV-2). Methods: Clinical samples were collected from February to July 2020 from Beijing Center for Diseases Prevention and Control and the Laboratory Department of China-Japan Friendship Hospital, to evaluate the sensitivity, specificity, anti-interference ability, precision and clinical sample coincidence rate of fast nucleic acid detection system for SARS-CoV-2. The analytical sensitivity was determined by a dilution series of 20 replications for each concentration. Analytical specificity study was performed by testing organisms whose infection produces symptoms similar to those observed at the onset of corona virus disease 2019 (COVID-19), and of the normal or pathogenic microflora that may be present in specimens collected. Potential interference substances were evaluated with different concentration in the interference study. Precision study was conducted by estimating intra-and inter-batch variability. Clinical evaluation was performed by testing 230 oropharyngeal swab specimens and 95 sputum specimens in fast nucleic acid detection system, comparing with conventional real-time fluorescent quantitative PCR (RT-qPCR) and clinical diagnostic results. Results: The analytical sensitivity of SARS-CoV-2 using fast nucleic acid detection system was 400 copies/ml. The result is negative for testing with the organisms that may likely in the circulating area or causing similar symptoms with SARS-CoV-2 and human nucleic acid, indicating that no cross reactivity with organisms. The results of precision test showed that the Coefficient of variation of Ct value of high, medium and low concentration samples was 1.90%-3.92%, and all of them were less than 5% in intra-and inter-batch testing. The results of the samples were still positive after adding the potential interfering substances, indicating that the possible interfering substances in the samples had no effect on the results. 98.46% and 97.85% diagnosis results of fast nucleic acid detection system were consistent with RT-qPCR and clinical diagnostic results, respectively. Conclusion: The fast nucleic acid detection system based on molecular parallel reaction can be used as a selection method for SARS-CoV-2 testing.