Back in April, the Chronicle reported that getting tested for Covid-19 was “not a simple matter.” Who would have thought that five months later the testing situation would still be so discouragingly confusing? The most reliable diagnostic test so far—the molecular nose-swab method known scientifically as the PCR (polymerase chain reaction) technique—is still far from being available on demand as once promised. And even for those able to get a test without much hassle, the lag time between being tested and getting results is often so great that the effort is in some ways a waste of time. Meanwhile, skepticism about the reliability of antigen tests that also use nose-swabs but offer a quicker result, seems to be holding up mass production or distribution of those.
COVID-19 is affecting the lives of each one of us. We are lucky to live in a town like Cornwall, where the number of cases has stayed low. But we are not immune, even with the self-quarantine restrictions for visitors from most states outside the Northeast. Among those with potentially the greatest exposure are healthcare workers, teachers and students, store clerks and staff, or anyone who has to interact with strangers as part of their work. Widespread, routine testing of people who are still asymptomatic seems to be the only way to effectively guard against community spread of the illness.
The September issue of the Chronicle lists several nearby spots where those of us without symptoms can get the most common current nose-swab test. Looking forward, there may be a simpler solution on the way, one that even originates within Connecticut. Just this past week the U.S. Food and Drug Administration granted emergency approval to SalivaDirect, a new saliva-based diagnostic test created by the Yale School of Public Health. The protocol for the procedure has been validated by the results of tests performed on asymptomatic players and staff of the National Basketball Association. The test uses a variety of commonly available reagents and instruments, and can easily be adapted as necessary by any certified laboratory. It also eliminates the use of nasal swabs that have sometimes become scarce (not to mention that using them can cause the patient discomfort and be hazardous to health care workers). Most important, the SalivaDirect lab procedure promises to be as reliable as that involving nose swabs.
Although Yale research scientist Anne Wyllie says “there is still some fine-tuning that needs to be done,” she believes SalivaDirect can be easily scaled up and “could be a game-changer in COVID-19 diagnostics,” decreasing both testing time and cost. The Jackson Laboratory for Genomic Medicine in Farmington will work with Yale to bring the test to the wider public. If the effort succeeds and “cheap alternatives like SalivaDirect can be implemented across the country,” says Wyllie’s research partner Nathan Grubaugh, “we may finally get a handle on this pandemic, even before a vaccine.”
For more information on the use of saliva for COVID-19 testing, see this video: https://publichealth.yale.edu/media-player/5173/. For information on SalivaDirect: https://covidtrackerct.com/about-salivadirect/.
—Paul De Angelis
📸: Woman in photo is Anne Wyllie, one of the two researchers at the Yale School of Public Health who spearheaded the development of the SalivaDirect test.