How To Restore Loss Of Smell, Taste After Covid-19

As the COVID-19 pandemic spread around the world anosmia and dysgeusia were quickly recognised as two of the key presenting symptoms.

- Gayan Suriya Arachchi

Temporary loss of smell, or anosmia, is the main neurological symptom and one of the earliest and most commonly reported indicators of COVID-19. For today's article our source person is Dr. Sujeewa Weerasinghe who is the National Organizer of the Chartered Society of Physiotherapist and the vice President of the World Disability and Rehabilitation Professionals Association.

Patients with viral upper respiratory infections to experience a temporary — or sometimes permanent loss of taste or smell. These symptoms appear to be particularly prevalent in COVID19. Studies suggest it better predicts the disease than other well-known symptoms such as fever and cough, but the underlying mechanisms for loss of smell in patients with COVID-19 have been unclear. Up to 80% of people who test positive for COVID-19 have subjective complaints of smell or taste loss. That percentage rises when these patients are tested using objective methods that measure smell function. Most patients first notice problems with their sense of smell, but because the smell is necessary to taste the flavor, the symptoms are often connected.

Now, an international team of researchers led by neuroscientists at Harvard Medical School has identified the olfactory cell types in the upper nasal cavity most vulnerable to infection by SARS-CoV-2, the virus that causes COVID-19. Several studies suggest that infection of nonneuronal cell types may be responsible for anosmia in COVID-19 patients and help inform efforts to better understand the progression of the disease. This implies that in most cases, SARS-CoV-2 infection is unlikely to permanently damage olfactory neural circuits and lead to persistent anosmia, Datta added, a condition that is associated with a variety of mental and social health issues, particularly depression and anxiety.

How can a virus cause smell and taste loss?