New study looks at potential COVID-19 'scratch-and-sniff test'

Posted at 5:56 PM, Jul 26, 2021

SAN DIEGO (KGTV) — As COVID-19 cases continue to climb, a new study by researchers at UC San Diego suggests there is a cheap and easy way to screen people for the virus: a smell test.

The researchers found that a scratch-and-sniff test featuring a single scent was able to detect 75 percent of people infected with COVID compared to a hospital-grade diagnostic, according to a study published this month.

The test, called a SAFER Card, presents users with six potential options like mint, banana, or grape. After smelling the scent on the card, the participant checks their answer on a phone app.

Correctly identifying the scent was a strong predictor of a clean bill of health; the study found 95 percent of people without COVID passed the test.

“We saw that compared to symptoms like cough, fever, or fatigue, failing the smell card was actually the best predictor of testing positive for COVID-19 on PCR,” said UCSD surgical resident Dr. Mena Said, a co-author of the study.

The SAFER Card was developed by a Texas mom and family physician named Dr. Sarah Davis.

“This is not trying to completely diagnose COVID, but it's trying to figure out who needs to go get a COVID test,” Davis said. “I wanted something that was really quick and easy, that you could use at the door while checking temperature and symptoms.”

Davis came up with the idea after her daughter returned from working as a camp counselor last summer.

“When she came home she had very mild symptoms,” Davis said. “And then all of a sudden, she really noticed a diminished sense of smell.”

Studies show about 80 percent of COVID-19 patients experience smell loss, but many never notice it. Only about 30 percent are aware of the smell loss.

Polymerase chain reaction or PCR testing is considered the gold standard way to diagnose COVID, but it takes time and expensive equipment. One PCR test can cost more than $100.

Rapid antigen tests can deliver results in minutes, but over-the-counter versions cost about $24 for a two-pack.

The SAFER Card costs $1 or less, and shares results in seconds.

“You can overcome it not being quite as accurate because you can use it so much more frequently,” Dr. Davis said. “I think it would be fantastic to be used very regularly.”

A study last month found smell tests like these given every one to three days can reduce cases and keep outbreaks under control, suggesting a quick sniff of grape, berry or banana might save lives.

This story originally reported by Derek Staahl on