COVID 19 - Investigate the loss of smell and taste

The loss of smell and taste are now well known symptoms associated with a positive diagnosis of COVID-19. However, there was a time - back in March 2020 - when very little was known about COVID and the link between those suffering from a loss of smell and taste and the virus that would go on to cause a pandemic had not yet been made. It was those who chose to investigate this issue who potentially helped to reveal the scale of what was really happening.

One of the most common symptoms of COVID-19

The loss of smell and taste is something that many medical professionals already associated with viruses. Before COVID-19 it was thought to complicate around 1% of upper respiratory tract infections and tended to peak in the month of March, alongside the infections and regular viruses it often accompanied. So, it was initially no surprise when, in March 2020, there were cases involving loss of smell and taste. However, all that changed when the medical community started to notice significant increases in this symptom, including among staff on front line COVID wards.

Establishing diagnostic value

A letter written on behalf of the British Rhinological Society and ENT UK sent to Public Health England was the beginning of the investigation into how these symptoms were associated with the virus. It triggered a wave of interest in loss of smell and taste as indicators of COVID-19 but at the time was hampered by low levels of testing. However, eventually it became obvious that this was one of the best predictors of a positive result, as it often appeared before other symptoms or even where there were no other symptoms. This led many experts to question whether the olfactory system was a significant defence mechanism against a neurotropic virus.

Identifying the permanent impact

One of the major concerns for patients experiencing this particular symptom was whether they would be left with a permanently damaged sense of taste and smell. Many people recover from the loss of taste and smell during the first four weeks. However, around 10% report having serious problems that last around six months and 50% continue to experience some sort of issue, although not serious, for the same length of time. Oral and topical steroids have been found to have some benefits but this remains an issue for many people post-COVID. While the loss of taste and smell may not seem a particularly life threatening problem it can have a negative impact on mental health. Some have even described the loss of taste and smell as the loss of an important coping mechanism. Smells evoke memories and the taste of food brings pleasure and when these two are removed from the equation life can suddenly take on a very two dimensional quality.

Investigating the loss of smell and taste associated with COVID-19 was one of the big breakthroughs in being able to identify those potentially infected and put isolation measures in place. Its ongoing impact on sufferers is still an important topic of discussion