What if there was a less irritating way to test for Covid?

If you have been to a Covid-19 testing centre, you probably would not want a repeat of that experience.

A nasal swab can be irritating.

What if you could have avoided that test by simply testing if you have lost your sense of smell?

The Centres for Diseases Control and Prevention lists anosmia (loss of smell) as one of the symptoms for Covid-19. A new modelling study that is pre-print proposes screening for anosmia to identify asymptomatic cases of Covid-19 since they are likely to spread the disease unsuspectingly.

Detect loss of smell

If the clinical trials go through and the study gets published in a scientific journal, the new testing method might help in reducing Covid-19 transmission.

The new kit, like a thermo-gun, can only detect loss of smell as one of the symptoms of Covid-19.

“The kit is basically a single card with five odorants on it. This can basically be printed and so can be easily done at scale,” Derek Toomre, a professor of Cell Biology at Yale University and one of the researchers, tells HealthyNation.

When using the kit, some tests can detect only the complete loss of smell. Others can detect both a partial loss (hyposmia) and complete loss (anosmia). The test takes about 45 seconds and the results come out almost immediately.

Daniel Larremore, an assistant professor at the University of Colorado and the lead researcher of the study, tells HealthyNation the model focused on whether the daily, weekly or every three days use of an anosmia screening test could limit the spread of the coronavirus.

“At present this idea is not yet put into practice, but our study predicts that it would be effective, provided that tests were used daily or every three days,” explains Dr Larremore.

Asymptomatic person

It is important to note that the sniff test will not be used to diagnose Covid-19 but simply to find out if an asymptomatic person already has lost the sense of smell. That means that the widely used Polymerase Chain Reaction (PCR) test, or in some cases the antigen test, will still be needed especially after someone is found to have anosmia.

“Tests like the PCR can be expensive and slow, while rapid antigen testing may also be too costly to use regularly. We, therefore, wanted to understand if it might be cheaper—yet still effective—to use anosmia,” says Dr Larremore.

The researchers say there are ongoing clinical trials in regard to the theoretical model for smell tests that is also being looked at for peer review. Brazil and South Africa are some of the places where the clinical trials are going on.

“By our calculations, screening tests for an unexpected loss of smell could help to find enough infections to bring down the spread of the virus meaningfully,” says Dr Larremore