Sensitivity, Specificity, Positive Rate and Consistency of Two Kits in SARS-CoV-2 Nucleic Acid Detection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was a highly transmissible and pathogenic coronavirus and it emerged in late 2019. SARS-CoV-2 had caused a pandemic of acute respiratory disease and its name was coronavirus disease 2019 (COVID-19). It threatened human health and public safety. This study would analyze and evaluate two different kinds of SARS-CoV-2 nucleic acid detection reagents which could provide value for accurate detection.

80 patients were randomly selected in the First Affiliated Hospital of Anhui Medical University in December 2022 and 80 oropharyngeal swabs were collected. Nucleic acid was extracted first, and then two real-time fluorescent quantitative RT-PCR nucleic acid amplification reagents were used to detect ORF1ab and N genes. Statistical software was used to compare and analyze the results.

Among 80 patients, 57 were males and 23 were females with an age range of 5 - 90 years with an average age of 65.7 years. Most of the specimens were collected from Department of Infectious Diseases and Department of Respiratory and Critical care. Compared with regent Reference, the sensitivity of regent A and B was 88.3% and 93.3% and the specificity was 90.0% and 95.0%, respectively. The positive rates of the double target genes were 85.0% and 93.3%, the positive rates of ORF1ab gene were 86.7% and 95.0% and the positive rates of N gene were 88.3% and 96.7%, respectively. The Kappa values were all greater than 0.75, indicating high consistency.

Between two nucleic acid detection reagents, reagent B had higher sensitivity and specificity. And the positive rate and consistency of reagent B were also higher than that of reagent A, with statistical significance. For weakly positive specimens with low viral load, it was recommended to use another reagent with higher sensitivity to retest and ensure the accuracy and repeatability of the results.