© 2021 MJH Live Science and Infectious Diseases. all rights reserved.

© 2021 MJH Life Sciences™ and Contagion Live. all rights reserved.

According to a new study by researchers at McGill University, saliva testing for coronavirus disease 2019 (COVID-19) is as effective as standard nasopharyngeal testing.

A new study shows that the Saliva Nucleic Acid Amplification Test (NAAT) for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is accurate, and its sensitivity and specificity are similar to those of nasopharyngeal NAAT.

The systematic review and meta-analysis published on JAMA Internal Medicine included 8 peer-reviewed studies and 8 preprints, involving a total of 5922 samples.

"The biggest takeaway is that whether you use a nasopharyngeal swab (nasal swab) or a saliva sample for the test, you can trust the results as much," Guillaume Butler-Laporte, MD, of the McGill University Health Center told Contagion®. "However, saliva tests are simpler, more comfortable, and do not require trained nurses. Therefore, they represent an attractive alternative to our current best tests."

The pooled sensitivity of saliva NAAT was 83.2% (95% confidence interval [CrI], 74.7%-91.4%), while the NAAT sensitivity of nasopharyngeal swabs was 84.8% (95% CrI, 76.8%-92.4%). Research. The pooled specificity of saliva NAAT was 99.2% (95% CrI, 98.2%-99.8%), and the pooled specificity of nasopharyngeal swab NAAT was 98.9% (95% CrI, 97.4%-99.8%).

"Our biggest surprise is actually our main result," Butler Laporte said. "In the past, the nasopharyngeal test has proven to be very accurate in many other viral infections, and it was indeed the standard test for upper respiratory tract infections at the beginning of the pandemic. So initially we thought we would see saliva samples that would be worse, but we felt surprise."

The research included in the analysis comes from the United States, Asia, Europe, and Australia. Fifteen of these studies included outpatients, and 9 studies included only outpatient participants with no or mild symptoms. In 5 of these studies, only patients with COVID-19-like symptoms were recruited, and one study recruited hospitalized patients.

Of the 5922 samples, 941 produced positive results and 4981 produced negative results.

"There is now a well-researched alternative to conventional testing," Butler Laporte said. "This is most valuable to laboratory medicine and public health professionals, who can now provide these tests to clinicians because they know they are still providing the best tests for patients."

The authors of the study urge testing centers to make saliva testing the first choice, especially for large-scale screening.

"The next step is to make it more widely available," Butler Laporte said. "Another step is to take advantage of the fact that the test is easier to perform and may deploy it as part of a larger testing campaign for more difficult-to-reach populations (such as children, college students, homeless people, etc.). But this may require specialized To ensure that it is completed correctly. Therefore, our research actually only opens the door to this possibility."

The limitations of the study include differences in the study population and test time, as well as the under-representation of hospitalized and critically ill patients. Measurements in different studies may also be slightly different.

The Infectious Disease Society of America (IDSA) recently updated its COVID-19 testing guidelines to include saliva testing.

Kimberly Hanson, MD, MHS, associate professor of internal medicine at the University of Utah School of Medicine and member of the IDSA board of directors, said: “Recently, there are a large number of papers studying the performance of these different sample types, especially saliva.” Time. "We learned that the saliva [test] actually looks good."

New testing strategies are under development, including rapid tests developed by the University of California, Santa Cruz, and rapid tests developed by Decision Diagnostics using test strips. In July, the US Food and Drug Administration granted emergency use authorization to test the color of COVID-19 without clinical monitoring. In November, Lucira COVID-19 All was obtained for the first COVID-19 self-test at home. -In EUA-a test suite.