Can the odor test screen people with COVID?

That reality doesn’t exist. But as the virus spreads out of control, the country is struggling to get it back to normal life, so some scientists at least bring us closer with a simple test consisting of only stinking pieces of paper. I think I can do it.

This test cannot look for the virus itself or diagnose the disease. Rather, it screens for olfactory loss, one of COVID-19’s trademarks. Since last spring, many researchers have recognized a condition, also known as anosmia, as one of the best indicators of ongoing coronavirus infection, and can identify people who are not feeling sick otherwise. It came to be.

Smell tests cannot flag people who are infected with the coronavirus and have no symptoms at all. However, in studies that have not yet been published in scientific journals, mathematical models may detect cases sufficient to significantly reduce transmission if sniff-based tests are performed widely and frequently. Was shown.

Daniel Laremore, a public health researcher at the University of Colorado at Boulder and the lead author of the study, emphasized that the work of his team is still purely theoretical. Although some odor tests are already used in clinical and research environments, the products tend to be expensive and cumbersome to use and are not widely available. And in the pandemic context, there is still no real data to support the effectiveness of the odor test as a frequent screen for coronavirus. Given the many test issues that have hampered previous pandemic efforts, some experts have distributed odor tests widely enough or cheated enough to reduce the spread of the infection. I’m wondering if it can be prevented.

Dr. Claire Hopkins, an otolaryngologist and author at Guy’s and St. Thomas Hospitals in the United Kingdom, said: A recent commentary on the subject of Lancet. “But I don’t see any value as a screening test.”

Reliable odor testing offers many potential benefits. As a screening tool for COVID-19, it can catch far more cases than the fever check, which most failed. Studies show that about 50% to 90% of people who test positive for coronavirus experience some measurable odor loss as a result of the virus causing havoc when it invades cells in the airways. To do.

Danielle Reed, Deputy Director of the Monell Chemical Senses Center in Philadelphia, said: “At this very moment, the virus is like a function in the nose.” It complements much of the information available from other tests. “Last month, Monel Reed and her colleagues were able to screen for COVID-19. I’ve posted a study explaining a quick odor test that might be, but it hasn’t been published in a scientific journal yet.

In contrast, only a few people with COVID-19 eventually spike in body temperature. Fever also tends to be momentary, but anosmia can last for days.

Derek Toumle, a cell biologist at Yale University and author of Lalemore’s treatise, said odor testing could come with attractively low prices, perhaps as low as 50 cents per card. Toomre wants his version to fit the bill. This test, the U-Smell-It test, is a small scratch and sniff scented smorgås board lined up on a paper card. People taking the test pick up the scent well, suck the guess into the smartphone app, punch it, and shoot to guess at least three of the five scents correctly. Different cards have different scent combinations, so there is no key to the answer to remember.

Toomre estimated that the test could be taken in less than a minute. It’s also a maker’s dream, he said. “You can run 50 million of these tests a day on one printer,” he said. He argued that such numbers could create huge dents in countries hampered by the widespread lack of access to tests that look directly for fragments of the coronavirus.

In their study, Larremore, Toomre, and their collaborator Roy Parker, a biochemist at the University of Colorado at Boulder, used computational tools to model such a scenario. Smell screens, administered daily or almost daily and captured at least 50% of new infections, were able to nearly suppress the outbreak, as well as more accurate and slower clinical tests performed only once a week.

According to Larremore, such tests could possibly serve as entrance screens on university campuses and offices, in combination with rapid virus testing. If researchers can find ways to minimize misuse, there may even be a place for them in the house.

Dr. Carol Jan, an otolaryngologist at the University of California, San Diego, said: “Repeating testing people will be a valuable part of this.”

Toomre is seeking an emergency use authorization for U-Smell-It from the Food and Drug Administration and has partnered with many groups in Europe and elsewhere to test under real-world conditions.

However, putting theory into practice involves many challenges. Smell tests that can reliably identify who has the coronavirus are not yet widely available, except for those who are sick of something else. (Hopkins pointed out several odor tests developed before the pandemic, each costing about $ 30 and with limited supply.) Missing infected people when deployed in large numbers. That is inevitable. The actual virus was unable to diagnose the disease on its own.

And the loss of heat-like odor is not unique to COVID-19. Other infections can blunt a person’s sense of smell. The same goes for allergies, stuffy noses due to colds, or just the process of aging. About 80% of people over the age of 75 have some degree of olfactory loss. Some people are born with anosmia.

In addition, in many cases of COVID-19, odor loss can be prolonged even after the virus is gone, and people are no longer contagious. Mr Yang said he would resume activities.

There are many ways to design an odor-based screen. Smell associated with foods that are popular in some countries but not in others, such as bubble gum and licorice, can distort test results for some individuals. People who grow up in urban areas may find it difficult to recognize the scent of nature, such as pine trees and freshly cut grass.

Smell is also strictly on or off, not in a dual sense. Reed advocated a step for test takers to assess the odor intensity of the test. This is the recognition that the coronavirus can significantly reduce the sensation of odor, but it cannot eliminate it.

However, the more complex the test, the more difficult it is to manufacture and deploy quickly. Also, no test works with 100% accuracy, even if it is a fully designed test.

Dr. Ameet Kini, a pathologist at Loyola University Medical Center, pointed out that olfactory tests are not without problems associated with other types of tests, such as poor compliance and refusal to quarantine.

The smell screen is “probably better than nothing,” Kini said. “But there is no test to prevent a pandemic unless combined with other measures.”

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