In the study, researchers report preliminary results from a clinical trial of 40 subjects with COVID-19 which showed sloughed epithelial cells lining the mouth can be infected with SARS-CoV-2, the coronavirus that causes COVID-19. The amount of virus in patient saliva was positively correlated with taste and smell changes, according to the study.
Relying on oral cell identity maps, researchers also looked at where in the mouth the virus infects. They surveyed oral tissues with the highest levels of ACE2, the receptor that helps coronavirus grab and invade human cells.
Based on ACE2 expression and analysis of cadaver tissue, the most likely sites of infection in the mouth are the salivary glands, tongue and tonsil, the study showed.
The findings provide more evidence of the role of saliva in COVID-19. COVID-19 infection, specifically in the mouth, can allow the virus to spread internally and to others as the infected person breathes, speaks and coughs.
