Study suggests that the loss of smell caused by COVID-19 can last up to a year

A year after the SARS-CoV-2 coronavirus pandemic, scientific knowledge about the virus has changed a lot. For example, loss of smell (loss of smell) is an important symptom of COVID-19. Another condition that can affect affected patients is decreased olfactory capacity (hypo-smelling). However, it remains to be seen how long it can last. In this sense, a new study has revealed that patients, in rare cases, can have the condition for more than a year.

On the other hand, most cases (96.1%) recover objectively within one year, according to a study prepared by researchers at the University of Strasbourg in France and McGill University in Canada. The discovery was published in the scientific journal JAMA.

Study on duration of olfactory loss caused by COVID

In April 2020, the research team published the first results on a follow-up of COVID-19 patients who reported a loss of smell. Since then, cases of anosmia or hyposmia have been followed up to check the extent of the problem.

In the published article, the authors explain: “Over a year, at four-month intervals, patients were asked to complete a survey, and their olfactory function was assessed by psychophysical tests.” In all, 97 patients were evaluated, 67 of whom were women and the mean age was 38.8 years. The selection criteria were that the patient had an acute loss of smell for more than 7 days.

After the first 12 months of follow-up, the researchers found that not all patients returned to their senses fully. “Of these patients, 51 (52.6%) were subjected to subjective and objective olfactory testing and 46 (47.4%) to isolated subjective assessment,” they commented.

Discoveries about loss of smell

Eight months after the case, the survey confirmed complete recovery in 49 of 51 patients (96.1%) who underwent objective evaluation. In this sense, only two patients remained persistently problematic.

Among those who underwent self-assessment only, 13 of 46 patients (28.2%) reported satisfactory recovery within four months (7 with complete and 6 partial recovery), and the remaining 33 patients (71.7%) did so in 12 months (32 with complete recovery and 14 with partial recovery), the study authors reported.

They continued: “The persistent loss of smell associated with Covid-19 has an excellent prognosis, with almost complete recovery within a year.” However, the authors stress the need for larger studies of infection-related loss of smell and diversification of patients followed, such as more men and older adults.

To access the full article published on the JAMA Open Platform, click Here.