In a new study, researchers found a simple, scratch-and-sniff test could play a key role in curbing the spread of COVID-19, at a fraction of the cost of high-tech tests that are difficult to scale and take longer to return results.
The research was conducted by a team at CU Boulder.
Studies have shown that when simply asked about their symptoms, only about half of the people with COVID-19 report loss of smell, or anosmia.
But when given a standardized test, with no visual clues to alert them to what they’re smelling and a range of scents chosen to catch even faint loss of smell, that number rises to eight in 10, even among people with no other symptoms.
That’s far more prevalent than fever, which impacts fewer than one in four people with the virus. Anosmia also lasts longer, affecting patients for a week or more while fever may only last a day or two.
While fever is associated with many diseases, loss of smell without a stuffy nose is highly specific to COVID-19, possibly due to the fact the virus tends to enter the body and replicate via ACE2 receptors, which are extremely abundant in cells in nasal passages believed to influence the sense of smell.
In the study, the team used mathematical modeling to predict the effect of smell-testing in several different hypothetical scenarios, including on a college campus of 20,000 people where individuals were tested once a week, every three days or daily; and, at a one-day event where it was used for point-of-entry screening.
In each case, the sniff-test served not as a definitive diagnostic test, but as a screening tool.
Those who failed would be referred for a gold-standard PCR (polymerase chain reaction) test in the campus model, or a rapid antigen test for the point-of-entry screening model.
Results depended on how early anosmia set in, how common it was and how willing people were to get tested.
But in general, testing for the sense of smell every three days worked better than weekly PCR tests in curbing infection—at a fraction of the cost.
This particular test is not commercially available yet, but the team applied for Emergency Use Authorization from the Food and Drug Administration in October.
They hope that it would allow for a fast and easy test that anyone can take anywhere and can be applied to any place that is using temperature screening as an inexpensive way to help avoid shutdowns, keep businesses open and decrease the terrible human toll.
One researcher of the study is Roy Parker, a professor of biochemistry and director of CU’s BioFrontiers Institute.
Copyright © 2020 Knowridge Science Report. All rights reserved.
