On Sept. 30, Hokkaido University Hospital announced that PCR testing using saliva is 90% accurate in detecting the novel coronavirus.
Since mid-June, the university has performed PCR tests on incoming travelers at Haneda and Kansai International Airports. The tests were also performed at healthcare centers nationwide on people who had had close contact with COVID-19 patients. Samples were collected from each person using both nasal swabbing and saliva collection. Analysis of the samples from 1,924 subjects revealed that the two methods had the same level of accuracy: 90% in sensitivity (meaning it will correctly identify 90% of people who are infected) and 99% in specificity (meaning it will correctly identify 99% of people who are not infected).
For healthcare workers, saliva collection is easier than nasal swabbing and presents a smaller risk of accidental infection. In the near future, demand for PCR tests using saliva may increase. “This finding will reassure people nationwide that they can safely choose a simpler and easier testing method,” says Professor Takanori Teshima of Hokkaido University Graduate School of Medicine.
According to the university, this is the first study in the world that has used a sample population exceeding 1,900 to determine the accuracy of PCR testing using saliva. The accuracy of such PCR tests had not been established previously.