Smell checks could help to
monitor the pandemic
Don´t wrinkle your nose at simple subjective tests.
Smell checks are the first indicators to show the effectiveness of restrictive measures.
For the majority of those infected, Covid 19 is usually accompanied by a sudden loss of smell. Smell disorders are the clearest and sometimes only symptom of the disease. Researchers have investigated whether a population-wide change in olfactory perception can indicate whether lockdown measures are taking effect. The answer is a positive one, as stated in the journal Nature Communications.
Between April and May 2020, an international team of researchers, the Global Consortium of Chemosensory Research, sent an online questionnaire around the world asking people to provide information about their sense of smell. Around 50,000 people took part. An analysis showed that in England, a country with less strict lockdown measures, the number of people with olfactory disorders fell more slowly than in countries that had more stringent measures, such as Italy and France. In terms of the number of infected people, when using traditional monitoring methods, the positive effect of stricter measures became apparent some two weeks later than when smell checks were used.
“I think it would be motivating if people could see just a few days after a lockdown whether the measures were working,” states Sara Spinelli, a researcher at the University of Florence and co-author of the study.
In another study, an international team from the Karolinska Institute in Sweden asked 2,440 people in Stockholm to smell five scents in their household on a regular basis. These included Nutella and toothpaste. They were asked to indicate the intensity of the scent on a scale. With the help of the changes in intensity perception over time, the researchers were able to predict the number of Covid-19 infected people in Sweden with a high degree of probability.
Dr. Johan Lundström, co-author of this study, is surprised that those responsible for pandemic monitoring have shown no interest in the method. He suspects that medical professionals and epidemiologists are skeptical of the results of subjective olfactory assessments. „Of course a PCR test would be more meaningful,“ says Thomas Hummel, who was also involved in the study. But a population-wide smell check is a quick, easy and cheap way to get an idea of the spread of the virus.
If you want to test your sense of smell and want to support Covid-19 research, you can do so here: https://gcchemosensr.org/
The text appeared in January 2021 in the Neue Zürcher Zeitung
translated by Martin Cook
title picture: sniffing stick / Fabienne Hübener
picture 1 (coffee): Tim Douglas / pexels