Mouth covid-19 infections
COVID-19 has been around for only a little more than a year. Most research into the novel coronavirus has focused on the lungs and nose. Now, a new study underscores the mouth as the primary source for COVID-19 infection. This highlights the importance of continuing to practice social distancing and wearing a face covering.
Researchers from the National Institute of Dental and Craniofacial Research and the University of North Carolina conducted a study that shows the coronavirus can infect the salivary glands and replicate there. In some instances, this phenomena led to prolonged disease when infected saliva was swallowed into the stomach and gastrointestinal tract or aspirated to the lungs leading to pneumonia.
Covid-19 oral infection studies
The results of this study have yet to be peer-reviewed.
“Our results show oral infection of COVID-19 may be underappreciated,”
said senior study author Kevin M. Byrd, research instructor at the UNC Adams School of Dentistry and the Anthony R. Volpe Research Scholar at the American Dental Association Science and Research Institute.
“Like nasal infection, oral infection could underlie the asymptomatic spread that makes this disease so hard to contain.”
Byrd and Blake Warner, chief of the Salivary Disorders Unit at the National Institute of Dental and Craniofacial Research, coordinated the study with research conducted at the J. Craig Venter Institute, the UNC Marsico Lung Institute, Wellcome Sanger Institute, and the National Institutes of Health.
Covid-19 symptoms
One peculiar symptom of COVID-19 is persistent dry mouth and the loss of taste and/or smell. Researchers are exploring these oral symptoms and focusing on the mouth rather than lungs or nose.
In this particular study, the researchers showed preliminary results from a clinical trial involving 40 patients with COVID-19. These patients showed sloughed epithelial cells that line the mouth may be infected with SARS-CoV-2, which is the specific novel coronavirus that leads to COVID-19. The researchers also found a positive correlation between the amount of virus in the subject’s saliva and the changes to smell and taste.
The researchers also looked into where in the mouth the virus takes hold and infects the individual. With the help of oral cell identity maps, they surveyed oral tissues with the greatest levels of ACE2, which is the receptor that enables the coronavirus to cling to and invade human cells.
Based on analysis of cadaver tissues and ACE2 expression, the most likely infection sites in the mouth are the tongue, salivary glands, and tonsils.
This study offers more evidence of the role that saliva plays in COVID-19 infections. When it takes hold in the mouth, that can enable the virus to spread to other internal areas and to others as the infected person speaks, coughs, and breathes.
The researchers initiated their study in the early days of the pandemic. Their six months of collaboration have resulted in additional insights into the ways the COVID-19 virus infects the mouth and throat.
The innovative work has led to the establishment of the Oral and Craniofacial Biological Network as a part of the Human Cell Atlas. The network is committed to creating comprehensive maps of oral and craniofacial cells that may lead to greater understanding of oral health and oral diseases. The network intends to openly share its research findings.