Novel coronavirus infects and replicates in salivary glands

A study conducted by scientists at the University of São Paulo (USP) shows that the novel coronavirus (SARS-CoV-2), which causes COVID-19, infects and replicates in salivary gland cells. The finding was announced by the São Paulo Research Foundation (Fapesp).

By analyzing samples from salivary glands from patients who died due to COVID-19 complications, the experts found that the tissues specialized in the production and secretion of saliva serve as reservoir for the novel coronavirus.

“This is the first account of a respiratory virus capable of infected and replicating in the salivary glands. Until then, it was believed that only viruses causing high prevalence diseases, like herpes, used salivary glands as reservoir. This may help explain why SARS-CoV-2 is so infectious,” the first author of the study, Bruno Fernandes Matuck, PhD student at USP’s dentistry school, told the Fapesp agency.

The biopsies were conducted through ultrassound in 24 patients who died as a result of COVID-19, with an average of 53 years of age, for the extraction of samples from the parotid, submandibular, and smaller glands. The material was then submitted to molecular analyses to identify the virus. According to the study, results found the virus is more than two thirds of the samples.

“We have observed several viruses grouping in salivary gland cells, which shows that they’re replicating inside them. There were not present in these cells passively,” Matuck said.

The research results were published in the Journal of Pathology. They should provide the basis for researchers evaluating whether the mouth can be a direct gateway for the entry of the novel coronavirus in human beings.