Mouth's Cells Also Infected by Coronavirus.

• Position: SARS-CoV-2

Evidence that SARS-CoV-2, the virus that causes COVID-19, infects cells in the mouth has been found by an international team of scientists. While it is well known that the upper airways and lungs are primary sites of SARS-CoV-2 infection, there are clues the virus can infect cells in other parts of the body, such as the digestive system, blood vessels, kidneys, and, as this study shows, the mouth.

The potential of the virus to infect multiple areas of the body might help explain the wide-ranging symptoms experienced by COVID-19 patients, including oral symptoms such as taste loss, dry mouth, and blistering. Moreover, the findings point to the possibility that the mouth plays a role in transmitting SARS-CoV-2 to the lungs or digestive system via saliva laden with virus from infected oral cells.

A better understanding of the mouth's involvement could inform strategies to reduce viral transmission within and outside the body. The team was led by researchers at the National Institute of Dental and Craniofacial Research and the University of North Carolina, Chapel Hill.

Researchers already know that the saliva of people with COVID-19 can contain high levels of SARS-CoV-2, and studies suggest that saliva testing is nearly as reliable as deep nasal swabbing for diagnosing COVID-19. What scientists do not entirely know, however, is where SARS-CoV-2 in the saliva comes from. In people with COVID-19 who have respiratory symptoms, virus in saliva possibly comes in part from nasal drainage or sputum coughed up from the lungs. However, that may not explain...