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Introduction
Infection with the new coronavirus (severe acute respiratory syndrome coronavirus 2/SARS- CoV-2) or COVID-19 was first registered in December 2019 in China and then later spread rapidly to the rest of the world. In Bosnia and Herzepovina, the first infected person was registered on Sth March 2020 in Banja Luka. Corona infection is primarily a respiratory disease, but the SARS-CoV-2 virus also penetrates other orpans, causing various symptoms, including olfactory and gustatory dysfunction, which is why we can consider COVID-19 as a multisystem disease. In General, adults with SARS-CoV-2 infection can be grouped into the several categories: asymptomatic or presymptomatic infection; mild i/mess; moderateness; severeimess; critical illness. Mild illness can include different symptoms: fever, cough, sore throat, malaise, headache, muscle pain, nausea, vomiting, diarrhea, loss of taste and smell, but do not have shortness of breath, dyspnea, or abnormal chest imap inp2.

Aim of this paper is to present review of some aspects of the olfactory and gustatory dysfunction in SARS-CoV-2 infection. COVID-19 and anosmia and ageusia Olfactory dysfunction (OD) associated with a viral infection of the upper respiratory tract is not onIy related to infection  with the  SARS-CoV-2. Namely, different viral infections, sinus that it accounts for about 40% of the total incidence of OD, and is more common in women and in age over 50 years^ ^-7. According to Cowart et al approximately two thirds of the patients who present to specialized chemosensory clinical centers complain oftaste loss, but the vast majority oftested patients display olfactory rather than gustatory dysfunction as the basis for their taste complaint. The duration of PVOD are quite variable (from one week to one or two years) and intensity depending on the speed of regeneration of the neuroepitheIium 0. Usually, a one third of patients begin recovery after a few months and achives a full recovery after 13 months. However, if severity of PVOD is greater and if lasts longer, the recovery of olfactory function is very modest (9-10). Although olfactory dysfunction after corona virus infection was previously recorded in SARS pandemic in 2002., at the very beginning of the COVID-19 pandemic, the acute loss of smell and taste was not considered an important symptom of SARS-CoV-2 infection  1. 3. However, soon after the first mentions of anosmia among the symptoms of COVID-19, acute loss of smell and taste were recognized as key diagnostic symptoms reported by approximately 60% of infected individuals.

Futrthermore, OD is also one of the most common neurological complications reported among patients with diseases, and head trauma, as wll as Parkinson coviD-1919-20 disease could also cause OD3, but, SARS-CoV-2 Symptoms of olfactroy and gustatory dysfu4ion, has been found to cause a more severe form respectively include anosmia (complete lack of hyposmia compared to other seasonal cold of olfactory sense), hyposmia (reduced viruses4. It has long been known that postviral olfactory sense), parosmia (distorted olfactory olfactory dysfunction (PVOD) is the main  sense), and phantosmia  (sensing odors that cause of clinically significant loss of smell and dont exist).
 
The first report that mentions anosmia and ageusia in patients with COVID-19, is a report by Mao et aI21 which they determined that in  the 214 patients they analyzed, 5.6% had hypogeusia, and 5.1% hyposmia. The most common clinical course of olfactory dysfunction is with an acute onset of hyposmia or anosmia, respectively. Recovery from this disorder usually occurs a few days to a week after the onset 3 ^. However, more than of 20% (up to 60) of patients, report persistently diminished smell at 6 months and 1 year2‘- 23, with 40% of them experiencing qualitative changes in the sense of smell in a disorder known  as parosmia 24-2a5

Epidemiology
A larpe number of studies have been published on the different frequency of these disorders in people with corona infection. The incidence of olfactory dysfunction and taste dysfunction    ranpes  32-87%    and 35-89%, respectively, with a concomitant incidence of olfactory and taste dysfunctions reported to be about 35%2^-2’. OD is more frequent in females than in males and is more common in the younger ape proups between 20 to 40 years old2 3*. About 10% of the patients had anosmia/hyposmia and apeusia/hypoapeusua preceding the onset of other symptoms, and there have been many patients not even showing other symptoms2’. There are reports of differences in the incidences of OD depending on peopraphic areas, with hipher frequencies in Western countries (over 50%), than in Asian countries (about 30% or less)2’-33 presented with apeusia, anosmia or both. All subjects had normalization of anosmia or apeusia with an average duration of 6.89 days3^. A multicenter study conducted in several countries in Europe at the bepinninp of the COVID-19 pandemic (from 12 hospitals) which included 417 COVID-19 (263 females/154 males) subjects; 85.6% of patients reported olfactory and 88.0% gustatory dysfunctions with a significant association between both disorders (p < 0.001); females were significantly more affected by olfactory and gustatory dysfunctions than males (p = 0.001); olfactory dysfunction appeared before the other symptoms in 11.8% of cases. The early olfactory recovery rate was 44.0% 35.

In one study from Kathmandu out of 300 patients, prevalence of loss of smell was 54% and loss of taste was 53%. Both of the symptoms were present in 45% of patients. Authors noted that the severity of the disease has a statistically significant effect on the loss of smell and taste whereas tender and smoking history has no significant difference over it3^ In one of the first a meta-analysis (up to 15th March 2021), published in October 2021, the prevalence of post-COVID-19 symptoms in hospitalized and non-hospitalized patients recovered from COVID-19 (15,244 hospitalized and 9,011 non-hospitalized patients) anosmia was present in 10—20%, ageusia in 15—20% of analyzed patients37. In another meta-analysis, in which (the CINAHL, PubMed, EMBASE, Scopus, and Web of Science databases were searched from 2019 to August 2021) published in November 2022 (sample included 7623
 
According to a report from Doha, Qatar, in a hospitalised and 1133 non-hospitalised patients) primary care health center, out of 141 anosmia/ageusia were present in 24% of  respondents this was 24.82% subjects patients(7%- 47%)3 inflammatory response, cytokine action, and greater damage to the cortex 3 4’. Theris also one speculation that suggests that the COVID-19 virus affects the non-neuronal olfactory epithelium causing anosmia and the associated taste dysfunctions. This cold be the acceptable mechanism because majority of the patients with SARS-CoV-2 infection are of the mild severity, and most of the smell and taste abnormalities resolve within short period34 48

Prognosis
A little is known about the clinical course of change in sense of smell and taste after SARS- CoV-2 infection, with inconsistent evidence on the duration of recovery. 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 4’ ^1. Furthermore, recent studies of long covid have already reported a substantial burden of brain fog, anxiety, and depression, it remains uncertain if persistent smell dysfunction after covid-19 might prognosticate an increased risk of long term neurological sequelae or neurodegenerative disorders 4.

Conclusion
The frequency of anosmia and ageusia in patients in patients with COVID-19 vary widely, and most often, it is about high percentages (about 60% and more) being the primary symptom in about 12% of patients. For now, it is more or less possible to only speculate on the mechanism of olfactory and gustatory dysfunction in patients with SARS- CoV-2 infection. 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 neurological consequences these disorders may have and on mental health in general. 
Corresponding Author:
Osman Sinanović Medical Faculty, University of Tuzla, Tuzla, Bosnia and Herzegovina; Sarajevo Medical School, Sarajevo School of Science and Technology, Sarajevo, Bosnia and Herzegovina; International 
Conflicts of Interest Statement: None

Acknowledgement:
None 

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