Abstract :

Severe acute respiratory syndrome coronavirus (SARS-CoV-2) is a glycan-coated coronavirus with an exposed receptor-binding domain (RBD), capable of binding to the angiotensin-converting enzyme-2 (ACE2) receptors and entering the cell through the cleavage of the spike proteins by the extracellular host enzyme Transmembrane serine protease 2 (TMPRSS2). The severity of the infection is directly associated with loss of taste (ageusia) and loss of smell, varying from hyposmia (reduced perception of smell) to anosmia (complete loss of smell). The mechanisms underlying the independent symptoms remain inconclusive; however, have been linked to sustentacular cell infection, changes in the olfactory bulb and subcortical regions of the brain, defects in the respiratory centres of the central nervous system and cerebral glucose abnormalities. The survey for this cross-sectional study was conducted in 2021 and involved 126 individuals who were exposed to or tested positive for COVID-19, through the Reverse transcription polymerase chain reaction (RT-PCR). 6.3% of covid-negative and 34.9% covid-positive individuals exposed to COVID-19, experienced anosmia and ageusia. This study aims to identify patterns in symptoms presented when an individual is infected with COVID-19; focusing on the correlation between anosmia and ageusia and associated visual impairments or cognitive difficulties. The understanding of varied symptom combinations observed amongst individuals differing in age, sex, comorbidities or vaccination status could aid doctors and healthcare practitioners to provide a prognosis specific to the subset to which the patients belong, depending on their symptom combinations and severity for the same.

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Keywords :

Ageusia, Anosmia, Blood-Brain Barrier (BBB), Olfactory Epithelium (OE), Olfactory Sensory Neurons (OSNs).

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