The study, published in Nature Medicine, notes the app COVID Symptom Study had 2.6 million users after three weeks across the U.S, U.K. and Sweden. The app was able to collect data from asymptomatic patients as well as those with symptoms.
The researchers found that loss of taste and smell are better indicators of COVID-19 than fever and cough.
“We report that loss of smell and taste is a potential predictor of COVID-19 in addition to other, more established, symptoms including high temperature and a new, persistent cough,” the researchers wrote in the study. “COVID-19 appears to cause problems of smell receptors in line with many other respiratory viruses, including previous coronaviruses thought to account for 10–15 [percent] of cases of anosmia.”
Anosmia is the loss of smell.