A group of Brazilian scientists first detected the presence of the new coronavirus in the gums of some patients who have died from complications from Covid-19, academic sources said Thursday.
The discovery is the result of a study by the Medical Faculty of the University of São Paulo (USP) and was published in the Journal of Oral Microbiology.
“The presence of SARS-CoV-2 in periodontal tissues may be one of the factors contributing to the presence of this virus in the saliva of infected patients,”; said Bruno Matuck, one of the state-sponsored authors of the study on the São Paulo Research Funding Foundation (FAPESP).
Other viruses such as herpes, Epstein-Barr or cytomegalovirus had previously been identified in the gingival tissue.
On this basis, Brazilian scientists hypothesized that the new coronavirus could multiply in the oral cavity and thus occur in saliva due to its high infection rate compared to other pathogens in the respiratory tract.
To prove this hypothesis, scientists took samples of the salivary glands, gums, and upper respiratory tract, and taste buds from seven patients who died from complications related to Covid-19.
Clinical analyzes confirmed the presence of SARS-CoV-2 in periodontal tissues in five of the seven deaths, in some cases up to 24 days after the onset of symptoms of the disease.
“These results show that periodontal tissue appears to be a target for SARS-CoV-2 and can contribute to its occurrence in saliva samples for a long time,” explained Matuck.
However, the study indicates that the presence of the virus in saliva for a long period of time “does not mean that the viral RNA particles are infectious for that long”.
“Other studies show that the infectious capacity of the virus decreases over time and peaks in 15 days,” said the coordinator of the study, Luiz Fernando Ferraz.
On the other hand, according to the report, the detection of the new coronavirus in the gums also confirms that inflating this tissue (periodontal disease) increases the risk of severe Covid 19 disease.
“As SARS-CoV-2 infects periodontal tissue, the increased secretion of gum fluid increases the salivary exposure to the virus,” explained Matuck.
Brazil, the country that currently has the most cases and deaths from Covid-19, is experiencing the worst moment of the pandemic, with an average of nearly 2,300 deaths a day and much of its public health system collapsing or coming close.
In just thirteen months of the pandemic, the country has already registered more than 300,000 deaths and 12.2 million people infected.