The Mouth as a Reservoir of SARS-CoV-2

This systematic review addresses the question: Is the oral cavity a reservoir of SARS-CoV-2 in participants who tested positive for viral RNA in nasopharyngeal and oropharyngeal samples? Four databases and a complementary search on the reference list of included studies were consulted. Paired reviewers independently searched the literature, extracted data, and evaluated the risk of bias (Joanna Briggs Institute).

A total of 3173 references were identified, and after a 2-phase selection, 24 studies were included. In total, 10 diagnostic test accuracy and 14 cross-sectional studies determined the presence of SARS-CoV-2 using real-time quantitative polymerase chain reaction (RT-qPCR) incorporating experimental and control samples. It was shown that saliva, gingival crevicular fluid, dental plaque, and gingival tissue harbored viral RNA. A high level of heterogenicity between studies was observed. The risk of bias analysis raised major concerns regarding the lack of clear criteria for inclusion, with most studies being of moderate to low quality. SARS-CoV-2 RNA is present in oral cavity samples, reinforcing the contribution of the oral cavity as a potential route of entry for infection and may offer a practical and affordable point-of-care platform for COVID-19 diagnosis. Furthermore, comprehending the oral cavity as a reservoir of SARS-CoV-2 may provide insight into its persistence and transmissibility.

The oral cavity can serve as a reservoir of SARS-CoV-2. Awareness of the significance of the oral cavity as a SARS-CoV-2 viral reservoir may help to shape COVID-19 containment measures and further potential therapeutic initiatives.