Abstract P21: Saliva as a testing specimen with or without pooling for SARS-CoV-2 detection by multiplex RT-PCR test

Abstract

Abstract Objectives Sensitive and high throughput molecular testing availability is essential during the COVID-19 pandemic. The vast majority of the SARS-CoV-2 molecular assays use nasopharyngeal or oropharyngeal swab specimens collected from suspected individuals. However, collecting these specimens has apparent drawbacks, including discomfort to patients and exposure risk to healthcare workers. Methods We developed and validated of QuantiVirus™ SARS-CoV-2 multiplex test using saliva as the testing specimens with pooling. Results The analytical sensitivity (LOD) was confirmed to be 100-200 copies/mL. For clinical evaluation, 85 known positive and 90 knowns negative NPS specimens were showed a positive predictive agreement of 100% and a negative predictive agreement of 98.9%. Twenty paired NPS and saliva samples were tested and showed overall 80% concordance rate without significant difference between NPS and saliva specimens by Wilcoxon signed-rank test (p=0.13). On a large scale of saliva-based population screening, the positive test rate was 1.79% among 389 saliva specimens. Furthermore, saliva sample pooling up to 6 samples for SARS-CoV-2 detection is feasible with sensitivity of 94.8% and specificity of 100%. Conclusions These results demonstrated that the clinical performance of saliva-based testing is comparable to that of NPS-based testing, and that pooling of saliva specimens for SARS-CoV-2 detection is feasible. Citation Format: Qing Sun, Jonathan Li, Hui Ren, Larry Pastor, Yulia Loginova, Joseph Wong, Zhao Zhang, Aiguo Zhang, Chuanyi Mark Lu, Michael Sha. Saliva as a testing specimen with or without pooling for SARS-CoV-2 detection by multiplex RT-PCR test [abstract]. In: Proceedings of the AACR Virtual Meeting: COVID-19 and Cancer; 2021 Feb 3-5. Philadelphia (PA): AACR; Clin Cancer Res 2021;27(6_Suppl):Abstract nr P21.