The Use of Saliva as a Diagnostic Specimen for SARS CoV-2 Molecular Diagnostic Testing for Pediatric Patients

Delaney, M.; Thomas, B.; Ralph, C. J.; Draper, K.; Moshgriz, M.; Granados, J.; Evangelista, M.; McGuire, M.; DeBiasi, R. L.; Simpson, J.; Campos, J.

Background Children are an important population to test for COVID-19 infection, particularly because they may shed the virus without displaying symptoms. Testing children for COVID-19 via sensitive molecular methods is important, although collecting nasopharyngeal (NP) specimens can be challenging. A less invasive mode of specimen collection that yields test results comparable to those from NP specimens would be beneficial to simplify sample collection. Methods To demonstrate that saliva is a suitable specimen for collection from children, the clinical usability/acceptability and the analytic performance of saliva were compared to NP specimens suspended in viral transport medium. Four different FDA EUA-approved real-time RT-PCR assays and one EUA approved saliva collection device were investigated. Results The study population included 526 patients between the ages of 3 and 61 years, 461 (88%) were <18 years, 425 were asymptomatic (81.1%), 92 were symptomatic (17.6%). Saliva mixed with saliva stabilizing buffer was found to yield comparable sensitivity to NP specimens when tested on the AllPlex SARS-CoV-2 molecular test (Seegene Inc). The analytic sensitivity of the AllPlex assay during testing of spiked saliva mixed with SpectrumDNA saliva stabilizer was found to be 250 genomic copies/mL. Conclusions Of the four FDA EUA-approved SARS-CoV-2 PCR assays studied, we found the AllPlex assay to be best suited for testing saliva specimens collected from children 5 years of age or older. The sensitivity of viral detection was equivalent to NP specimens when saliva specimens were mixed with the saliva stabilizer.