Evaluation of the Advanta Dx SARS-CoV-2 RT-PCR Assay, a High-Throughput Extraction-Free Diagnostic Test for the Detection of SARS-CoV-2 in Saliva: A Diagnostic Accuracy Study

Sofia Balaska; Dimitrios Pilalas; Anna Takardaki; Paraskevoula Koutra; Eleftheria Parasidou; Ioanna Gkeka; Areti Tychala; Georgios Meletis; Barbara Fyntanidou; Simeon Metallidis; Efthymia Protonotariou; Lemonia Skoura

doi:10.3390/diagnostics11101766

Evaluation of the Advanta Dx SARS-CoV-2 RT-PCR Assay, a High-Throughput Extraction-Free Diagnostic Test for the Detection of SARS-CoV-2 in Saliva: A Diagnostic Accuracy Study

Diagnostics (Basel). 2021 Sep 26;11(10):1766. doi: 10.3390/diagnostics11101766.

Affiliations

¹ Department of Microbiology, AHEPA University Hospital, Medical School, Aristotle University οf Thessaloniki, 54636 Thessaloniki, Greece.
² First Propedeutic Department of Internal Medicine, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece.
³ Emergency Department, AHEPA University Hospital, 54636 Thessaloniki, Greece.
⁴ First Department of Internal Medicine, Infectious Diseases Division, AHEPA University Hospital, Medical School, Aristotle University of Thessaloniki, 54636 Thessaloniki, Greece.

Abstract

Nasopharyngeal swab specimen (NPS) molecular testing is considered the gold standard for SARS-CoV-2 detection. However, saliva is an attractive, noninvasive specimen alternative. The aim of the study was to evaluate the diagnostic accuracy of Advanta Dx SARS-CoV-2 RT-PCR saliva-based assay against paired NPS tested with either NeumoDx^TM SARS-CoV-2 assay or Abbott Real Time SARS-CoV-2 assay as the reference method. We prospectively evaluated the method in two settings: a diagnostic outpatient and a healthcare worker screening convenience sample, collected in November-December 2020. SARS-CoV-2 was detected in 27.7% (61/220) of diagnostic samples and in 5% (10/200) of screening samples. Overall, saliva test in diagnostic samples had a sensitivity of 88.5% (77.8-95.3%) and specificity of 98.1% (94.6-99.6%); in screening samples, the sensitivity was 90% (55.5-99.7%) and specificity 100% (98.1-100%). Our data suggests that the Fluidigm Advanta Dx RT-PCR saliva-based assay may be a reliable diagnostic tool for COVID-19 diagnosis in symptomatic individuals and screening asymptomatic healthcare workers.

Keywords: COVID-19; PCR; SARS-CoV-2; saliva.