Saliva as Source of Detection for SARS-CoV-2

Overview

Background: Nasopharyngeal (NP) swabbing is being used to test for SARS-CoV-2 infection. For this, a swab is inserted deep into the back of the nose to collect a sample. It can cause discomfort for most people. Researchers want to find an easier way to collect samples. Objective: To learn if testing for SARSCoV-2 with a saliva sample only, a nasal swab from just the front part of the nostril only, or a saliva sample plus a nasal swab gives results that are as accurate as the NP swab. Eligibility: NIH staff members age 18 and older who are taking part in NIH CC SARS-CoV-2 surveillance. Design: The Occupational Medical Service (OMS) collects NP swabs as part of standard NIH staff screening. Participants will give 1 or 2 saliva samples and 1 or 2 nasal swabs when their NP swab is collected by OMS. If their NP swab was already collected, their OMS record will be reviewed for the result. If the NP swab result is positive, the participant will have another NP swab. At that time, they will also give 1 or 2 saliva samples and 1 or 2 nasal swabs. If the NP swab result is negative, they will give 1 or 2 saliva samples and 1 or 2 nasal swabs the next time they have an NP swab. For the saliva sample, participants will spit into a tube. For the nasal swab, the inside of the front part of the nostril will be swabbed. Participation ends after the study samples are collected. Participants can choose to keep giving saliva and nasal swab samples each time they have an NP swab.

Because of the inconvenience of nasopharyngeal (NP) testing for SARS-CoV-2 detection, we are interested in identifying different strategies for detecting infection. A technique that is less intrusive would put individuals undergoing testing at lower risk for complications, would likely increase compliance with subsequent tests, and would decrease risk to the providers who are conducting the test. For asymptomatic screening, some institutions are using midturbinate swabs instead of NP swabs, for increased compliance due to decreased discomfort. The NIH has switched to midturbinate collection in asymptomatic collections only. A test that would require only expectorating saliva and/or collection of a midturbinate swab would address the issues of NP collection discomfort. Saliva is the most preferred by patients or asymptomatic staff due to no collection in the nasal cavity at all. Although the CDC lists midturbinate swab as an acceptable specimen type, there are minimal data about the sensitivity of this collection for SARS-CoV-2, and decisions to use midturbinate swabs are based in part on experience with other respiratory viruses. Also, if saliva were found to be equivalent to NP for patient testing, there will be a benefit to future patients in providing this option for testing. Therefore, we propose to validate these sample types for SARS-CoV-2 detection. The RT-PCR results based on a saliva sample alone or a saliva sample coupled with a midturbinate swab, will be correlated with the results using surveillance or diagnostic swab samples to validate their use for SARS-CoV-2 detection.