Use of Self-Collected Saliva Samples for the Detection of SARS-CoV-2.

OBJECTIVE: Using a US Food and Drug Administration (FDA) emergency use authorization (EUA) reverse transcription polymerase chain reaction (RT-PCR) method, we examined the analytic performance accuracy of saliva specimens as compared to nasopharyngeal (NP) specimens in symptomatic patients. Correlation between test results and symptoms was also evaluated. METHODS: Over a 5-week period in 2020, 89 matched saliva and nasopharyngeal swabs were collected from individuals exhibiting symptoms consistent with SARS-CoV-2. Specimens were tested with an FDA EUA-approved RT-PCR method, and performance characteristics were compared. RESULTS: The concordance rate between saliva and nasopharyngeal testing was 93.26%. The mean cycle threshold value of saliva when compared to the NP specimen was 3.56 cycles higher. As compared to NP swab, saliva testing demonstrates acceptable agreement but lower sensitivity. CONCLUSION: When compared to a reference method using NP swabs, the use of saliva testing proved to be a reliable method. Self-collected saliva testing for SARS-CoV-2 allows for a viable option when trained staff or collection materials are in short supply.

Performance Accuracy of a Laboratory-Developed Real-Time RT-PCR Method for Detection of SARS-CoV-2 in Self-Collected Saliva Specimens.

OBJECTIVE: The ongoing COVID-19 pandemic caused by SARS-CoV-2 has challenged diagnostic laboratories to re-examine traditional methods for collecting specimens and sample types used in molecular testing. Our goal was to demonstrate that saliva can be used for detecting SARS-CoV-2 and correlates well with established molecular methods using nasopharyngeal (NP) swabs. METHODS: We examined use of a saliva collection device in conjunction with a laboratory-developed real-time reverse transcription-polymerase chain reaction (LDPCR) method for detecting SARS-CoV-2 in a symptomatic population and compared results with 2 US Food and Drug Administration (FDA)-approved methods (emergency use authorization [EUA]) that use specimens from NP swabs. RESULTS: The sensitivity of LDPCR compared with the reference methods was 75.0% (21/28); specificity, 98.1% (104/106). When cycle threshold values were compared between paired specimens using the LDPCR and a EUA reverse transcription PCR method, both targeting the open-reading frame gene, the mean value for saliva was 4.66 cycles higher than for NP specimens. CONCLUSION: Use of self-collected saliva in conjunction with an LDPCR for SARS-CoV-2 compared favorably with 2 FDA EUA methods using NP swabs. The use of an alternative sample type and assay method will aid in expanding the availability of testing during the ongoing COVID-19 pandemic.