Clinical Performance of the cobas Liat SARS-CoV-2 & Influenza A/B Assay in Nasal Samples

• DOI: 10.1007/s40291-022-00580-8
• Publication Date: 2022-04-07T18:03:51Z
• Authors: Yusaku Akashi; Michiko Horie; Junichi Kiyotaki; Yuto Takeuchi; Kenichi Togashi; Yuki Adachi; Atsuo Ueda; Shigeyuki Notake; Koji Nakamura; Norihiko Terada; Yoko Kurihara; Yoshihiko Kiyasu; Hiromichi Suzuki
• Keywords: 0301 basic medicine; 03 medical and health sciences; SARS-CoV-2; Nasopharynx; Influenza, Human; COVID-19; Humans; Original Research Article; Sensitivity and Specificity; 3. Good health

Point-of-care type molecular diagnostic tests have been used for detecting SARS-CoV-2, although their clinical utility with nasal samples has yet to be established. This study evaluated the clinical performance of the cobas Liat SARS-CoV-2 & Influenza A/B (Liat) assay in nasal samples.Nasal and nasopharyngeal samples were collected and were tested using the Liat, the cobas 6800 system and the cobas SARS-CoV-2 & Influenza A/B (cobas), and a method developed by National Institute of Infectious Diseases, Japan (NIID).A total of 814 nasal samples were collected. The Liat assay was positive for SARS-CoV-2 in 113 (13.9%). The total, positive, and negative concordance rate between the Liat and cobas/NIID assays were 99.3%/98.4%, 99.1%/100%, and 99.3%/98.2%, respectively. Five samples were positive only using the Liat assay. Their Ct values ranged from 31.9 to 37.2. The Ct values of the Liat assay were significantly lower (p < 0.001) but were correlated (p < 0.001) with those of other molecular assays. In the participants who tested positive for SARS-CoV-2 on the Liat assay using nasopharyngeal samples, 88.2% of their nasal samples also tested positive using the Liat assay.The Liat assay showed high concordance with other molecular assays in nasal samples. Some discordance occurred in samples with Ct values > 30 on the Liat assay.