Performance evaluation of the cobas SARS-CoV-2 Duo, a novel qualitative and quantitative assay, for the detection of SARS-CoV-2 RNA

Abstract

Viral load quantification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a critical measure for monitoring clinical responses of patients with COVID-19. The cobas SARS-CoV-2 Duo (Roche Molecular Systems, Inc.) uses the cobas 6800/8800 platform and is an automated real-time reverse transcription PCR (RT-PCR) assay for the qualitative detection of SARS-CoV-2 RNA (ORF1a and ORF1a/b non-structural regions) in nasal and nasopharyngeal specimens. This assay also performs quantitation of the SARS-CoV-2 RNA level in the collected specimen. The precision, accuracy, and linearity of the cobas SARS-CoV-2 Duo test were assessed and correlated with the cycle threshold (Ct) value of the cobas SARS-CoV-2 assay, and the cobas Liat SARS-CoV-2 and influenza A/B assay (Inf A/B) (cobas Liat) in 201 clinical nasopharyngeal swab specimens. The analytical measurement range of the cobas SARS-CoV-2 Duo has been verified to be 1.0E + 02 IU/mL to 1.0E + 09 IU/mL. The between- and within-run precision evaluation and the linearity results ( R 2 = 0.9961) of the cobas SARS-CoV-2 Duo were acceptable based on the verification criteria. A total of 201 nasopharyngeal specimens were evaluated. The positive, negative, and total agreements between the cobas SARS-CoV-2 Duo and the cobas SARS-CoV-2 assay were 93.5% (157 of 168), 75% (33 of 44), and 92.5% (186 of 201), respectively. The qualitative results (Ct values) from the cobas SARS-CoV-2 and the cobas Liat demonstrated good agreement with the quantitative results from the cobas SARS-CoV-2 Duo assay. In conclusion, the diagnostic performance of the cobas SARS-CoV-2 Duo assay is appropriate. It is a precise, accurate, and sensitive method for the detection of SARS-CoV-2 RNA and is comparable to two qualitative assays. IMPORTANCE Quantitative SARS-CoV-2 tests for viral load are necessary to guide patient treatment, as well as to determine infection control measures and policies. Although the real-time RT-PCR assays can report the Ct value to estimate the viral load, there are several serious concerns regarding the use of Ct values. Importantly, Ct values can vary significantly among between- and within-run methods. The diagnostic performance of the cobas SARS-CoV-2 Duo is appropriate. It is a precise, accurate, and sensitive method for the detection of SARS-CoV-2 RNA and is comparable to two qualitative assays (the cobas SARS-CoV-2 and the Liat cobas SARS-CoV-2 and Inf A/B). In contrast, using the Ct value to estimate viral load is not reliable, and utilization of a quantitative detection test, such as the cobas SARS-CoV-2 Duo, to accurately measure the viral load is needed.

Performance evaluation of the Panbio COVID-19/Flu A&B Panel for detection of SARS-CoV-2, influenza A, and influenza B antigens using mid-turbinate nasal swabs

“…Subjects were excluded from the study if they ( 1 ) had a nasal or a NP swab taken within the previous 4 h and were not available for further testing after 4 h had elapsed ( 2 ), had active nose bleeds or acute facial injuries/trauma ( 3 ), received a nasal vaccine (i.e., FluMist) within the previous 14 days ( 4 ), were taking or had taken an antiviral medication—e.g., amantadine, rimantadine, zanamivir, oseltamivir phosphate, and rimantadine—for influenza or COVID-19 within the previous 30 days ( 5 ), were enrolled in a study to evaluate an investigational drug ( 6 ), were unwilling or unable to provide informed consent, or ( 7 ) were part of a vulnerable population as deemed inappropriate for study by the site’s principal investigator and/or reviewing ethic committee. After verifying that each participant met all study inclusion criteria and none of the exclusion criteria, the study staff obtained written informed consent.…”

“…Early diagnosis is critical for the treatment of COVID-19. At present, most reported cases have been identified through qualitative detection methods of SARS-CoV-2 RNA, antigens, or antibodies ( 5 ).…”