A University College London (UCL) study suggests losing one's sense of taste or smell may be a more common sign of COVID-19 than other symptoms, including cough or fever. UCL’s study found that among 590 people who reported a loss of taste or smell, 80% of participants had COVID-19 antibodies.
Participants were recruited between 23 April and 14 May by Prof Rachel Batterham, the study’s lead author, via text message from four London GP surgeries. These surgeries then put forward any patients who had reported losing their smell or taste in the four weeks prior.
This has led experts to believe that a loss of sense of smell could be a more obvious indicator of COVID-19 than a cough or a fever.
The study only looked at people who had mild symptoms, while 40% of the participants had no other symptoms, other than the loss of smell or taste.
It was indicated as early as April this year that a loss of taste and smell could be COVID-19 symptoms. These were subsequently added to the UK’s official symptoms list in May.
Self-isolation guidance also instructs people experiencing a loss of smell or taste to self-isolate for 14 days. However, receiving a negative COVID-19 test result would negate the need to do this.
Despite the findings, Prof Batterham said that a cough or a fever are still the main symptoms to look out for.
Prof Batterham noted the main finding of the study reiterated the importance of people looking out for any changes or deteriorations in their sense of smell or taste. It is also vital for people to self-isolate if they realise they can't smell things like perfume, bleach, toothpaste, or coffee. She also added that these symptoms would occur without a blocked or runny nose.
The BBC reported the cause of these symptoms is thought to be that the virus invades cells located at the back of the throat and on the tongue. These are believed to be symptoms exclusive to COVID-19 as, unlike with a common cold, they occur without a person's airways being blocked.
Concerns have been raised surrounding these symptoms as people who display loss of smell and taste only could pose as a more significant threat to others, spreading the virus as they generally feel well and carry on with their lives as usual.