Scientists at the Faculty of Medicine of the University of São Paulo (FM-USP) discovered that the virus that causes Covid-19, the SARS-CoV-2, infects and replicates in salivary gland cell tissues.
The study was published in the international journal Journal of Pathology. The scientific methodology was conducted through analysis of samples from three types of salivary glands. They were collected through a minimally invasive autopsy in patients who died of Covid-19 at the Hospital das Clínicas at FM-USP.
“It is the first report of a respiratory virus capable of infecting and replicating in the salivary glands. Until then, it was believed that only viruses causing diseases with very high prevalence, such as herpes, used the salivary glands as a reservoir. This may help explain why Sars-CoV-2 is so infectious,” says one of the study's authors, Bruno Fernandes Matuck, a doctoral student at the USP Dental School.
The research results help to underline why the existence of large amounts of Sars-Cov-2 in saliva, a phenomenon that drove the diagnostic tests by collecting this fluid.
Finally, it appears that the high infection capacity of the new coronavirus it can be more harmful if compared to other viruses of respiratory origin, as it can become infected and replicate by the salivary glands. That is, it does not need to come into contact with nasal and pulmonary secretions to multiply and worsen clinical conditions.
In previous research, released in March this year, scientists had already found the presence of the virus' RNA in the periodontal tissue (or gums) of a patient who died from the disease. These preliminary studies were critical to the latest discoveries.