Why SARS-COV-2 virus is found abundantly in the saliva, study explains

As per a team of researchers in Brazil, the SARS-CoV-2 virus can not only infect tissues which produce salivary glands in our body but also turn them into reservoirs where it replicates. As per the researchers, this could be magnifying its infectious potential.

The study’s findings were first published in an article in the Journal of Pathology. It helps understand why the COVID-19 virus is found abundantly in saliva, which resulted in the development of saliva-based diagnostic testing methods like the RT-PCR test.

As per Bruno Fernandes Matuck, doctoral candidate at USP's Dental School, “This is the first report of a respiratory virus's capacity to infect and replicate in salivary glands. Until now it was thought that only viruses that cause highly prevalent diseases such as herpes used salivary glands as reservoirs. The discovery may help explain why SARS-CoV-2 is so infectious,”

The increased infectiousness of COVID-19 virus compares to other respiratory viruses spurred the hypothesis that it may be present in saliva without coming into contact with nasal and lung secretions, replicating in salivary gland cells.

The study observed tissue samples from 24 patients who succumbed to Covid-19. It found that two-thirds of the samples not just showed presence of the virus but also its replication in cells.

“We observed several viruses clustering in salivary gland cells, which showed that they were replicating there. They weren't in these cells passively,” Bruno Fernandes Matuck said.