US university researchers have received US government clearance for the first saliva test to help diagnose Covid-19, a new approach that could help expand testing options and reduce risks of infection for health care workers.
The US Food and Drug Administration (FDA) authorised the test under its emergency powers to quickly clear new tests and therapies to fight the outbreak, Rutgers University in New Jersey said.
The test initially will be available through hospitals and clinics affiliated with the school.
The announcement comes as communities across the US continue to struggle with testing to help track and contain the coronavirus.
The current approach to screening for Covid-19 requires health care workers to take a swab from a patient’s nose or throat.
To lessen infection risks, many hospitals and clinics instruct staff to discard gloves and masks after close contact with anyone who may have the virus. And many institutions are struggling with shortages of basic medical supplies, including gloves, masks and swabs.
With the new saliva-based test, patients are given a plastic tube into which they spit several times. They then hand the tube back to the health care worker for laboratory processing.
“This prevents health care professionals from having to actually be in the face of somebody that is symptomatic,” said Andrew Brooks, who directs the Rutgers lab that developed the test.
An infectious disease expert not involved with the new test said it would help overcome some of the patient discomfort and difficulties in taking swab samples.
“You want to be in all types of situations with all types of options so that we can have as much testing as possible in whatever form is suitable,” said Dr Amesh Adalja of Johns Hopkins University.
Dr Adalja noted that similar saliva tests have helped expand testing for HIV and other conditions.
Rutgers tested the accuracy of its method by taking both saliva and swab samples from 60 patients. The results from patients’ saliva samples had a 100% match with results from the swabs.
Rutgers developed the laboratory method for the test using saliva collection kits from Spectrum Solutions, a Utah company that provides similar devices for DNA-based ancestry testing services.
The Rutgers lab can currently process 10,000 patient samples per day, according to Mr Brooks.
In its authorisation letter to Rutgers, the FDA said the test should only be performed “in a health care setting under the supervision of a trained health care provider”.
The FDA has not cleared any Covid-19 tests for use at home, though several companies have announced plans to make them available.
Additionally, the FDA said patients who test negative with the saliva-based kit should have their results confirmed with a second testing method.