Saliva in the Diagnosis of COVID-19: A Review and New Research Directions
Larissa Leci Fernandes, Valéria Bordallo Pacheco, Leandro Borges, Harleen K. Athwal, Fernanda de Paula Eduardo, Letícia Mello Bezinelli, Luciana Côrrea, Manuel Jiménez, Nailê Damé‐Teixeira, Isabelle M.A. Lombaert, Débora Heller
Abstract
This review presents literature that highlights saliva's utility as a biofluid in the diagnosis and monitoring of COVID-19. A systematic search was performed in 5 electronic databases (PubMed, Embase, LILACS, Scopus, and Web of Science). Studies were eligible for inclusion if they assessed the potential diagnostic value and/or other discriminatory properties of biological markers in the saliva of patients with COVID-19. As of July 22, 2020, a total of 28 studies have investigated the presence of SARS-CoV-2 RNA in saliva. Several of those studies confirmed reliable detection of SARS-CoV-2 in the saliva of patients with COVID-19. Saliva offered sensitivity and specificity for SARS-CoV-2 detection comparable to that of the current standard of nasopharyngeal and throat swabs. However, the utility of saliva in diagnosing COVID-19 infection remains understudied. Clinical studies with larger patient populations that measure recordings at different stages during the disease are still necessary to confirm the accuracy of COVID-19 diagnosis with saliva. Nevertheless, the utility of saliva as a diagnostic tool opens the possibility of using rapid and less invasive diagnostic strategies by targeting bioanalytes rather than the pathogen.