Loss of Smell and Taste Are Solid Indicators of COVID-19

An international team created a mobile device app that allows users to report repeatedly on symptoms thought to be relevant for COVID-19 and to self-report results of reverse transcription polymerase chain reaction (RT-PCR) testing for SARS-CoV-2. The app has been used by more than 2.6 million people in the U.K. and U.S. who believed they had symptoms of COVID-19. Of about 18,500 participants who underwent RT-PCR testing, about 7000 tested positive.

Loss of smell and taste were much more common in participants who were RT-PCR positive than in those who were RT-PCR negative (65% vs. 22%; odds ratio, 6.74); results were similar regardless of country of domicile, age, or sex. These two symptoms best discriminated test-positive from test-negativ…