Abstract
Background and aim: SARS-CoV-2 quick testing is relevant for the containment of new pandemic waves. Antigen testing in self-collected saliva might be useful. We compared salivary and naso-pharyngeal swab (NPS) SARS-CoV-2 antigen detection by a rapid chemiluminescent assay (CLEIA) and two different point-of-care (POC) immunochromatographic assays, with results of molecular testing.
Methods: 234 patients were prospectively enrolled. Paired self-collected saliva (Salivette) and NPS were obtained to perform rRT-PCR, chemiluminescent (Lumipulse G) and POC (NPS: Fujirebio and Abbott; saliva: Fujirebio) for SARS-CoV-2 antigen detection.
Results: The overall agreement between NPS and saliva rRT-PCR was 78.7%, reaching 91.7% at the first week from symptoms. SARS-CoV-2 CLEIA antigen was highly accurate in distinguishing positive and negative NPS (ROC-AUC = 0.939, 95%CI:0.903-0.977), with 81.6% sensitivity and 93.8% specificity. This assay on saliva reached the optimal value within 7 days from symptoms onset (Sensitivity: 72%; Specificity: 97%). Saliva POC antigen was limited in sensitivity (13%), performing better in NPS (Sensitivity: 48% and 66%; Specificity: 100% and 99% for Espline and Abbott respectively), depending on viral loads.
Conclusions: Self-collected saliva is a valid alternative to NPS for SARS-CoV-2 detection by molecular, but also by CLEIA antigen testing, which is therefore potentially useful for large scale screening.
Keywords: COVID-19; Chemiluminescence; Naso-pharyngeal swab; Point-of-care.
【저자키워드】 COVID-19, point-of-care, chemiluminescence, Naso-pharyngeal swab, 【초록키워드】 SARS-CoV-2, Saliva, pandemic, POC, Symptoms, Antigen, point-of-care, SARS-CoV-2 detection, sensitivity, specificity, rRT-PCR, Patient, Swab, SARS-CoV-2 antigen, molecular, immunochromatographic, chemiluminescence, Containment, Chemiluminescent assay, Abbott, Pharyngeal swab, viral loads, symptoms onset, Fujirebio, positive, NPs, salivary, enrolled, assays, reached, 【제목키워드】 prospective cohort study, SARS-CoV-2 antigen,