Clinical features of coronavirus infection with impaired sense of smell

Previously, olfactory disturbances were not considered as a possible single symptom of an acute period of coronavirus infection. Aim: to identify the clinical features of low-symptomatic forms of COVID-19 coronavirus infection occurring with olfactory dysfunction. Materials and methods: the study was conducted on the basis of the Federal State Budgetary Institution of the Central Research Institute of Epidemiology of Rospotrebnadzor by questioning people who have suffered a coronavirus infection. A total of 39,676 people were interviewed, of whom 24,086 (60.70%) had suffered some form of new coronavirus infection COVID-19. Methods of descriptive statistics were used for statistical analysis of the research results. Results: olfactory dysfunction may be the only symptom of the acute period of COVID-19 coronavirus infection in 4%. The occurrence of this symptom depends on the dominant circulating genovariant (maximum at Alpha is 7.8%), the basic reproductive number (inverse relationship, Pearson correlation coefficient -0.9) and the age of the patient (more often in persons under 44 years of age). The occurrence of the symptom does not depend on the patient's gender. Patients with olfactory dysfunction with COVID-19 coronavirus infection are significantly less likely (4.2% vs. 12.6%, P = 0.04) to require hospitalization and oxygen therapy (2.5% vs. 32.2%, P 0.001). Conclusion: olfactory dysfunction may be the only symptom of the acute period of COVID-19 coronavirus infection, which allows us to suggest its isolation into a separate form. The occurrence of this form depends on the dominant circulating genovariant, the basic reproductive number of the virus and the age of the patient. Patients with this form of coronavirus infection are less likely to require hospitalization and oxygen therapy.