Researchers at the University of Saskatchewan College of Dentistry will use more than $550,000 in funding from the Canadian Institutes of Health Research (CIHR) to develop a diagnostic test that detects SARS-CoV-2 peptides in saliva.
The test would be less invasive and more sensitive than current methods, the researchers said, and it would take less than five minutes to produce results. Also, people at home and in remote locations that don’t have medical facilities could perform the test as well.
The researchers are developing a prototype testing device that is about the size of a cell phone. It will be similar to devices used in pregnancy testing, with an indicator that turns a certain color when the virus biomarker combines with SARS-CoV-2 antibodies, indicating the presence of the virus in saliva.
“We expect that the accuracy of this test will be high because the peptide/proteins we are using is a marker for a specific SARS-CoV-2 antibody, whereas other tests often aren’t that specific,” said Walter Siqueira, PhD, DDS, associate dean of academics and leader of the study.
“As well other saliva-based tests are based on RNA, which synthesizes proteins, but this test is based on proteins themselves, and since proteins last longer in the saliva than RNA, the virus is more detectable,” said Siqueira.
The test also will be able to detect mild or asymptomatic COVID-19 cases, which is a shortfall of some existing tests, said Siqueira, who has secured partnerships with the Saskatchewan Health Authority and Royal University Hospital to acquire saliva samples for the research.
Siqueira expects the new test to be a low-cost alternative to other tests so it can be available to the general population. It could be available by March of 2021.
Siqueira leads the USask Salivary Proteomics Research Laboratory, one of only a few labs in the world focused on applied salivary research, the researchers said. Previously, Siqueira has had success in identifying a specific protein signature in saliva for the Zika virus and creating a detection method for Zika virus using saliva.
Mohan Babu, PhD, MSc, of the University of Regina will lead the part of the study aimed at developing antiviral peptides to block the SARS-CoV-2 virus from entering or replicating human cells. Darryl Falzarano, PhD, of the USask Vaccine and Infectious Disease Organization-International Vaccine Centre is working on that part of the study as well.
In a second awarded project, Siqueira will work with Sreenath Madathil, BDS, MSc, PhD, and Paul Allison, BDS, MSc, PhD, of the McGill University Faculty of Dentistry to collect saliva samples from dentists across the country to determine the incidence rate of COVID-19 among dentists as they return to work.
“The close contact between dentists and patients, along with the use of aerosol-generating procedures, makes dental offices a potential high-risk environment for the COVID-19 transmission,” said Siqueria.
“Now that dental offices are beginning to reopen, they are implementing infection control, treatment protocols, and other procedures, but there is minimal scientific evidence to support these measures,” said Siqueria. “More information is needed to ensure we have evidence-based infection control guidelines that protect both the patients and the dentists.”
Saliva samples will be collected from 220 dentists every four weeks for a period of one year to test for COVID-19. Questionnaires also will be distributed. The data collected will enable the team to form a clearer picture of the risk in dental offices, which personal protective equipment should be used, and which infection control measures should be kept in place to ensure continued patient and dentist safety.