However, putting theory into practice will pose many challenges. Odor tests, which can reliably identify people with the coronavirus while excluding people with something else, are not yet widely used. (Dr. Hopkins pointed out some odor tests that developed before the pandemicwhich cost around $ 30 each and have limited availability.) Should they ever be imported in large quantities, they would inevitably miss some infected people and, unlike tests that look for the actual virus, could never be themselves diagnose a disease.
And loss of smell like fever does not only exist with Covid-19. Other infections can weaken a person’s sense of smell. So can allergies, nasal congestion from a cold or simply the aging process. About 80 percent of people over 75 years of age have some degree of odor loss. Some people are born anosmic.
Additionally, in many cases of Covid-19, the loss of smell can last long after the virus disappears and people are no longer contagious – a complication that could put some people in purgatory after Covid if they are forced to look at scent screens leave activity to resume, said Dr. Yan.
There are also many ways to design a scent-based screen. Odors associated with foods that are popular in some countries but not in others, such as chewing gum or licorice, can skew test results for some people. People who grew up in metropolitan areas may not easily recognize smells from nature like pine trees or freshly cut grass.
Smell is also not a binary sense, exclusively on or off. Dr. Reed advocated a move in which test-takers rate the intensity of a test’s odors – confirmation that the coronavirus can drastically reduce, but not eliminate, the sense of smell.
The more complicated the test, the more difficult it is to quickly make and use. And no test, not even a perfectly designed one, would work with 100 percent accuracy.
Dr. Ameet Kini, a pathologist at Loyola University Medical Center, pointed out that odor testing would also not be free of problems associated with other types of testing, such as: B. poor compliance or refusal to isolate.