This is one of the now known symptoms of the coronavirus: loss of smell. But if around 90% of people who have lost this sense because of Covid-19 find it again within a few weeks, this is not the case for the remaining 10%. This symptom can sometimes last for more than a year. It was while following several patients with anosmia that Pierre-Marie Lledo, head of the perception and memory unit at the Institut Pasteur, ended up finding traces of the virus nested in the olfactory epithelium, an organ located in nasal cavity and which allows you to recognize odors.
A considerable advance therefore, which leads to many new questions. “We do not yet know if this virus continues to replicate and if by breathing people can continue to be infected, for example. And secondly, we had never imagined until then that it would be necessary to treat the organ sensory with antivirals or anti-inflammatories for months afterwards, ”explains the scientist.
This ongoing research could indeed give a boost to the development of antiviral sprays to treat these patients. Researchers are also wondering if the neurological sequelae of certain patients are precisely linked to this loss of smell, and a clinical trial has just been launched to find the answer.
A virus “which prolongs disabilities”
Gabriel Lépousez, neurobiologist at the Institut Pasteur, specialist in sensory perception, and smell in particular, also took part in this discovery. “It is very recent as a finding. And we have been able to show that in these few people who have a long anosmia, even if the virus is no longer present from the point of view ‘positive test’, well it manages to nest and to hide in this mucous membrane to continue to damage and prolong the damage or the handicaps “, he detailed at the microphone of Europe Matin Tuesday.
According to him, researchers are beginning to truly understand this virus and research is advancing considerably on it. “We realize that the virus has a tropism, that is to say that it likes to target the cells of the upper respiratory tract and in particular those of the olfactory mucosa which are located at the top of your nasal cavity, between your two eyes. It is this small organ that allows you to feel and apprehend all the volatile molecules in the environment, “he explained.
Stimulate your neurons to regain smell
But the neurobiologist is reassuring. “The olfactory system regenerates all the time. For a cell to mature again, it takes 30 days, but it also takes 3 to 6 months to reconnect with the brain. This is the longest stage. in this process of convalescence. You must therefore take the time and patience to measure your convalescence and one of the best ways that we have found today to do so is to stimulate yourself “, he continued .
He therefore advises to smell odors on a regular basis, morning and evening, but also to diversify his diet to increase his chances of stimulating his neurons. “Take familiar smells, so you will recognize them more easily and the pleasure will be renewed”, edicts the researcher.