A large percentage of people with COVID-19 lose some sense of smell.

Now, researchers are working on a way to use fast, cheap scratch-and-sniff technology to provide early detection of the disease.

Three teams have received more than $900,000 from the National Institutes of Health for a two-year study assessing two at-home tests for smell loss.

"The reason we've done it this way as opposed to using something much fancier is that there's unique opportunity with smell testing to do things incredibly fast and incredibly inexpensively," said Rick Gerkin, an Arizona State University professor who specializes in how the brain represents smell perception, learning and behavior.

ASU is partnering with the University of Florida and Pennsylvania State University on the grant, which is funded by the Coronavirus Aid, Relief and Economic Security (CARES) Act and the NIH's Rapid Acceleration of Diagnostics (RADx) program.

The three schools will evaluate the tests using participants in their local communities who are COVID-positive and COVID-negative. In a separate evaluation, they will recruit participants to take a smell test weekly over six weeks to see if they can detect the emergence of the disease in a community.

The self-administered tests use an app and QR code to guide participants and report results. One smell test will use familiar odors, like smoke or onions, while the other will require users to detect various concentrations of a single smell.

Gerkin says the advantage of the approach lies in its potential to detect one of the virus's earliest diagnostic signals.

"Something that's incredibly cheap, incredibly fast can beat something that's incredibly accurate, if you can deploy it widely enough," Gerkin says.

People with sudden smell loss should seek out lab test to confirm their diagnosis.