Are Salivary Diagnostics for COVID-19 as Reliable as Nasopharyngeal Swabs?
Excerpts and edited notes for this blog were referenced from a post by Perio Implant Advisory written by Dr. Scott Froum, DDS on August 26th, 2020. The following blog is presented for viewers to validate, accept and/or decline its content and findings on their own.
A new noninvasive COVID-19 test utilizing salivary diagnostics has recently been released for public and point-of-care use. But are salivary diagnostics as reliable as the gold standard nasopharyngeal swabs? Dr. Scott Froum examines the research.
Nasopharyngeal swabs administered by health-care workers have become the gold standard in testing for COVID-19. Nasopharyngeal swabs demonstrate a high sensitivity and specificity. False negatives and positives can occur, however, and these tests are open to operator error, lab contamination, and handling errors that can compromise accuracy. The swab has to be placed deep into the nasopharyngeal region of the patient, often eliciting an unpleasant sensation. Due to high demand, the process may take up to three weeks to receive laboratory results after administering the test.
Recently a new noninvasive COVID-19 test utilizing salivary diagnostics has been released for public and point-of-care use. Sample collection is easy, and the test is less prone to operator error. The question is, are salivary diagnostics as reliable as the gold standard nasopharyngeal swabs? A new prospective study in the Journal of Clinical Microbiology looked to answer that question.
The study was performed at the University of Utah and analyzed more than 1,100 samples from 386 patients, comparing traditional deep nasopharyngeal swabs collected by health-care workers to self-collected samples (by patients) using anterior nasal swabs and saliva collection. This study found that patient-collected saliva tests for SARS-CoV-2 was just as accurate as traditional nasopharyngeal swab collection by health-care workers.
Saliva tests have definite benefits over traditional nasopharyngeal swabs:
1. Health-care workers do not need to be exposed to patients upon collection.
2. These tests are noninvasive and simple to use.
3. The patient does not have to go to a clinic with sick patients to be tested.
4. Lab results can take 48–72 hours depending on demand.
The salivary diagnostics testing procedure:
A. The patient expectorates (spits) into a collection tube up to a required volume.
B. The patient screws on a buffer solution and mixes the saliva and buffer.
C. The patient places the sample in an envelope and mails it overnight to the lab.
Mass implementation of a COVID-19 test that is accurate, easy to use, and efficient with test results can assist both health care and public health officials in ending the COVID-19 pandemic in an expedited manner.