ĐÁNH GIÁ SỰ ĐỒNG NHẤT VỀ KẾT QUẢ REALTIME RT-PCR TRÊN HỆ THỐNG XÉT NGHIỆM COBAS 6800 SO VỚI QUY TRÌNH CỦA WHO TRONG CHẨN ĐOÁN XÁC ĐỊNH SARS-CoV-2

Abstract

The clinical diagnostic efficiency of SARS-CoV-2 PCR methods plays a vital role in case detection, treatment and epidemic prevention. We conducted this study to evaluate the concordance of Realtime RT-PCR test results performed on Cobas 6800 system comparing with the procedure recommended by the World Health Organization (WHO) on 309 nasopharyngeal swab samples collected at the National Hospital for Tropical Diseases from 2020 to 2022. The results showed that the Cobas 6800 system detected more positive samples than those tested by the WHO protocol, in which the number of positive samples tested by the WHO and Cobas 6800 protocol were 232/309 (75%) 281/309 (91%), respectively. The Kappa coefficient reflects the similarity between the two test methods was 0.43, corresponding to the average degree of concordance. The average difference between the Ct value of the E gene according to the WHO protocol compared with the Ct value of the ORF gene and the E gene on Cobas 6800 is 3.18 and 2.38, respectively, indicating a 10-time higher of virus-detecting capacity when using COBAS 6800 system compared to WHO protocol. Thus, the automated COBAS 6800 system should be used in urgent situations such as a novel epidemic for screening large numbers of samples as well as avoiding false negative results.