Loss of smell and taste not permanent in COVID-19: Harvard study

WION Web Team New Delhi, India Jul 30, 2020, 05.49 PM(IST)

Loss of smell and taste Photograph:( Reuters )

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Experts believe that the symptom of loss of smell is one of the most distinct symptom of the novel coronavirus, rather than cough, cold or fever.

One of the symptoms of the novel coronavirus is loss of the sense of smell and taste. A new research has now revealed the reason behind this loss of smell and taste.

Experts believe that the symptom of loss of smell is one of the most distinct symptom of the novel coronavirus, rather than cough, cold or fever.

Coronavirus, experts believe, latch onto cells via an enzyme known as ACE2 as an entry point to the human body. This makes cells containing this enzyme the most vulnerable.

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Till now it was believed that the virus directly attacked the sensory neurons. However, a new study by the Harvard University has revealed that the enzyme ACE2 is instead found in cells providing “metabolic and structural support” to those olfactory sensory neurons and to some stem and blood vessel cells.

“Our findings indicate that the novel coronavirus changes the sense of smell in patients not by directly infecting neurons but by affecting the function of supporting cells,” said senior study author Sandeep Robert Datta, associate professor of neurobiology in the Blavatnik Institute at Harvard, in a statement.

The study was published in a journal titled Science Advances.

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The study reveals that the olfactory sensory neurons do not have the genetic mechanism to encode the ACE2 receptor protein. This means that the virus cannot grab onto something and permanently damage it.

In simpler words, when a COVID-19 patient loses sense of smell and taste, the senses will come back once the patient recovers. The loss of smell and taste will not be permanent.

It means that a coronavirus infection most likely will not permanently damage sense of smell, Datta said.

“I think it’s good news, because once the infection clears, olfactory neurons don’t appear to need to be replaced or rebuilt from scratch,” Datta said.

“Anosmia seems like a curious phenomenon, but it can be devastating for the small fraction of people in whom it’s persistent. It can have serious psychological consequences and could be a major public health problem if we have a growing population with permanent loss of smell.”

However, Datta has cautioned that this study has only been published in a peer-reviewed journal as of now and they need more clarity on the data. “We need more data and a better understanding of the underlying mechanisms to confirm this conclusion,” he said.