Four out of five people with sudden loss of smell or taste tested positive for Covid-19 antibodies, finds a new study.
Scientists say the findings, published in PLOS Medicine, show that an acute loss of smell or taste is a ‘highly reliable’ virus indicator and should now be considered globally as a criterion for self-isolation, testing, and contact tracing.
The cohort study, which assessed health data from primary care centres in London, found that 78% of people who reported sudden loss of smell and/or taste at the height of the pandemic had SARS-CoV-2 antibodies. Of these people, 40% did not have a cough or fever. It is the first time such a figure has been calculated.
Lead author, Professor Rachel Batterham (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.”
Recruitment to the study took place between 23 April and 14 May 2020 by sending text messages 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. A total of 590 participants enrolled via a web-based platform and responded to questions about loss of smell and taste and other Covid-19–related symptoms.