Posted on: Aug 27, 2020
A saliva-based COVID-19 diagnostic that is being used to test thousands of students every day at the University of Illinois at Urbana-Champaign is now covered by an emergency use authorization (EUA) from the US Food and Drug Administration.
That clearance, announced on Aug. 19, makes it easier for other labs across the country to use the method and marks a significant milestone in using saliva samples for widespread screening of asymptomatic people returning to universities and workplaces.
The University of Illinois test, called I-COVID, relies on a sample-processing method developed by researchers there (bioRxiv 2020, DOI: 10.1101/2020.06.18.159434) and joins a growing list of saliva-based tests that promise to bypass some of the bottlenecks that are holding back testing efforts. The study describing the test was published earlier this year on a preprint server, and like the other preprint papers described in this story, it has not yet been peer reviewed.
The most common way to diagnose COVID-19 relies on an uncomfortable nasopharyngeal (NP) swab that is pushed deep into someone’s nostril to gather fluid from the back of their nose and throat. These samples are typically run through diagnostic devices that use reverse transcriptase polymerase chain reaction (RT-PCR) to detect the presence of RNA from SARS-CoV-2, the virus that causes COVID-19.
But this approach has several drawbacks. Gathering samples is laborious—the tests are most reliable when samples are taken by trained medical staff, who need to wear protective equipment to avoid exposure to the virus. The procedure is also unpleasant for the person being tested, possibly deterring people from taking repeated tests. Public health systems have also struggled with shortages of NP swabs, along with the reagents used to prepare the sample for RT-PCR.
The nice thing about saliva is that you don’t need a swab or any fancy equipment; you just spit in a tube.Source: Chemical & Engineering News read full article