About 5% of people with covid-19 experience a long-lasting disturbance of their sense of smell or taste, estimates a large study published Thursday, while it is still largely unknown how long this emblematic symptom of the disease can last.

“A significant proportion of patients with Covid-19 seem to develop a lasting change in their sense of taste or smell,” conclude the authors of this work published in one of the main scientific journals, the British Medical Journal (BMJ).

3500 patients questioned

Two and a half years after the start of the pandemic, loss of taste and smell, or their alteration, are now among the symptoms known as the most specific to Covid.

But there is a great lack of figures regarding its frequency and, above all, regarding the time it takes to remit and disappear. To answer this, the BMJ study compiled twenty previous works, representing a total of more than 3,500 patients. This approach gives more weight to this type of study than to isolated work.

At the end of this study, the authors conclude that after six months, 2% of patients say they have not recovered taste and 4% do the same with smell.

There is, however, a vagueness as to the fact of having fully recovered these senses, or only partially. Taking this element into account, the researchers estimate that these senses remain permanently disturbed in approximately 5% of patients: 5.6% for smell and 4.4% for taste.

This study chose to retain only papers that are based on self-reported patients having regained taste and smell. The latter are not evaluated by objective tests.

According to the authors, their figures would probably be higher if studies based on this type of evidence were included. Objective assessments tend to report more taste or smell problems than patients report.