COVID-19-related Loss of Smell and Taste Linked to Viral Staying Power in the Human Nose
May 6, 2021
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Loss of smell or taste, or both, is common in COVID-19 infected patients, particularly in patients with mild symptoms. Although research has focused on the causes underlying lung infections in COVID-19 patients, the causes of neurological symptoms have remained a mystery.
Researchers have now explained the mechanisms involved in the loss of smell (anosmia) in patients infected with SARS-CoV-2 at different stages of the disease, in an article published in
SARs-CoV-2 infects olfactory sensory neurons and enters the central nervous system through a process called retrograde invasion. [Source: Pierre-Marie Lledo/Institut Pasteur].Using noninvasive nasal brush sampling, scientists at the Institut Pasteur, CNRS, Inserm, University of Paris, and Assistance Publique – Hôpitaux de Paris, examined the nasal linings in 11 patients with COVID-19 reporting loss of smell and detected SARS-CoV-2 viral particles and inflammation in several cell types in the lining of the nasal cavity (olfactory neuroepithelium) including sensory neurons. The researchers showed SARS-CoV-2 infects and multiplies in the olfactory epithelium of hamsters and in individuals with COVID-19 for several months after infection.