The researchers, based in the UK, wrote in their study that people who lose their sense of smell or taste should consider self-isolation, even if they have no other symptoms.
The team studied 590 volunteers who experienced a new loss of smell or taste and tested 567 for Covid-19.
About 40% of those who tested positive for antibodies had neither fever nor cough.
Batterham and his colleagues also found that participants with loss of smell alone were nearly three times more likely than patients with taste loss alone to have Covid-19 antibodies, and participants with a combined loss of smell and taste were. four times more likely to have antibodies.
“These results suggest that a loss of smell is a highly specific symptom of Covid-19, in contrast to a loss of taste, despite their comparable frequency,” the researchers wrote in the study.
The study recruited its volunteers between April 23 and May 14, during the peak of the Covid-19 outbreak in London. The results have some limitations, including the fact that the study does not include a comparison group of people who did not lose their sense of smell and / or taste.
At the time, a government statement stated that “all individuals should self-isolate if they develop a new continuous cough, fever or anosmia.”