Anosmia and Ageusia in Sars-Cov-2 Infection

Abstract

Background: Corona infection is primarily a respiratory disease, but the SARS-CoV-2 virus also penetrates other organs, causing various symptoms, including olfactory and gustatory dysfunction, which is why we can consider COVID-19 as a multisystem disease. Aim: To present review of some aspects of the olfactory and gustatory dysfunction in SARS-CoV- infection. Methods: The article has an analytical character and review of the literature. Results and Discussion: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has a high similarity with SARS-CoV-1 and uses the same receptors to enter the human body (angiotensin-converting enzyme 2/ACE2). COVID-19 is primarily a disease of the respiratory system, but SARS-CoV-2 also penetrates the other organs including central nervous system (CNS). Patients with SARS-CoV-2 infection can experience a range of clinical manifestations, from no symptoms to critical illness. The entry of the virus into the brain can lead to different neurological and psychiatric manifestations, including loss of smell (anosmia) and the loss of taste (ageusia). The frequency of anosmia and ageusia in patients with COVID-19 varies widely, from 10 to 65%, being the primary symptom in about 12% of patients. For now, the etiopathogenesis of anosmia and ageusia in SARS-CoV-2 infection is still unknown. Most of the analyzed subjects reported olfactory recovery. However, anosmia and ageusia can last several months or even longer. While most patients are expected to recover their sense of smell or taste within the first three months, a major subpopulation of patients might develop long lasting dysfunction. Although a substantial proportion of patients with Covid-19 might develop long lasting of diferent level of ansomia and ageusia it is uncertain what proportion of patients develop persistent dysfunction. Anosmia/ageusia can be as an important risk factor for fog, anxiety, and depression that may show a prolonged and/or delayed impact. However, we do not yet know what long-term effects these disorders may have on the central nervous system and mental health in general. Conclusion: The COVID-19 is primarily a disease of the respiratory system, but SARS-CoV-2 also penetrates other organs (multisystem disease), causing various symptoms, including olfactory and gustatory dysfunction. The frequency of anosmia and ageusia in patients with COVID-19 is common but according to different papaers varies widely, from 10 to 65%, being the primary symptom in about 12% of patients. Most of the analyzed subjects reported olfactory recovery. However, anosmia and ageusia can last several months or even longer. We do not yet know what long-term consequences these disorders may have on the central nervous system and mental health in general.