Four out of five with sudden loss of smell or taste had COVID-19, study finds
Written by on 2 October 2020
Four out of five people who suddenly lost their senses of smell or taste tested positive for COVID-19 antibodies, new research indicates.
Scientists behind the study say the findings suggest an acute loss of smell or taste is a highly reliable virus indicator.
They say the loss of smell or taste should now be considered globally as a criterion for self-isolation, testing and contact tracing.
Researchers from UCL and UCLH (University College London Hospitals NHS Foundation Trust) looked at health data from primary care centres in London.
Their results showed 78% of people who reported sudden loss of smell and/or taste at the height of the pandemic had COVID-19 antibodies.
And of these people, 40% did not have a cough or fever. It is the first time such a figure has been calculated, according to the researchers.
Lead author Professor Rachel Batterham, of UCL Medicine and UCLH, said: “As we approach a second wave of infections, early recognition of COVID-19 symptoms by the public together with rapid self-isolation and testing will be of vital importance to limit the disease’s spread.
“While people in the UK who experience sudden onset loss of smell or taste are advised to self-isolate and seek a test, at a global level few countries recognise this symptom as a COVID-19 indicator – most focus on fever and respiratory symptoms.
“Our findings show that loss of smell and taste is a highly reliable indicator that someone is likely to have COVID-19 and if we are to reduce the spread of this pandemic, it should now be considered by governments globally as a criterion for self-isolation, testing, and contact tracing.”
Researchers sent texts to people registered with a number of primary care centres in London who had reported sudden loss in their sense of smell and/or taste between 23 April and 14 May.
A total of 590 participants enrolled via a web-based platform and responded to questions about loss of smell and taste and other coronavirus-related symptoms.
Of these, 567 had the history of their symptoms confirmed by a healthcare professional who supervised a test to establish if they had COVID-19 antibodies.
The study, published in PLOS Medicine, found 77.6% of the 567 people with smell and/or taste loss had SARS-CoV-2 antibodies.
Of these, 39.8% did not have a cough or fever, and those with loss of smell were three times more likely to have antibodies, compared with those with loss of taste.
Prof Batterham added: “Our research suggests a key public health message should be: people who notice a loss in their ability to smell everyday household odours such as garlic, onions, coffee, and perfumes should self-isolate and seek a coronavirus PCR swab test.”