The loss of smell that can occur with Covid-19 is very different from what people sometimes experience with a cold or flu. This is according to European researchers who studied the experiences of patients who recovered from coronavirus and published their findings in the journal Rhinology.
With Covid-19, the loss of smell can be sudden and almost complete. However, symptoms such as nasal congestion or severe nasal congestion are not usually observed: in most cases, people with coronavirus can breathe freely (problems with the lungs are another story).
Then there is the loss of taste. And it is a real loss: that is, the patients do not only experience a change in their sense of taste due to the loss of smell, which would be quite understandable, but they lose it completely, to the point of not being able to distinguish sweet from bitter. Specialists believe that the virus directly affects the nerve cells responsible for taste and smell.
It is not difficult to do a quick test at home. During the study, the group leader from the University of East Anglia, Professor Karl Philpot, selected a group of 30 volunteers: 10 were infected with the coronavirus, another 10 had a cold, and the last 10 were completely healthy. In Covid-19 patients, the loss of smell was particularly severe. They struggled to discriminate smells and could not distinguish between sweet and bitter.
“It seems that there are indeed characteristic signs that distinguish the coronavirus from other respiratory diseases,” says Professor Filpot. “And this is very important because testing for smell and taste would help distinguish patients with the coronavirus from those with the common flu or cold.”
According to the professor, people could successfully conduct such tests at home using readily available products such as coffee, garlic, lemons and sugar. At the same time, he emphasizes that regular testing, which involves taking samples from the nose and throat, is still necessary if coronavirus is suspected.
By the way, in most patients who recover from coronavirus, the sense of smell and taste return to normal within a few weeks. To understand the biochemical mechanism of olfactory loss, Professor Andrew Lane of Johns Hopkins University decided to look deeper into the noses of patients and made an important discovery, published in the European Respiratory Journal.
Testing for smell and taste would help distinguish patients with coronavirus from those with the common flu or cold. Professor Lane and his colleagues discovered an extremely high concentration of the enzyme ACE-2 (angiotensin-converting enzyme 2, or zinc-containing metalloenzyme) in the area responsible for olfaction. Scientists believe that this enzyme acts as a gateway for the coronavirus to enter the body’s cells and cause infection.
“We are currently conducting further laboratory experiments to determine whether the virus actually uses these cells to invade and infect the human body,” explains Professor Lane. “If this is indeed the case, we could potentially combat this infection with antiviral therapy by administering treatment directly through the nose.”