Loss of smell or taste strongest predictor of Covid-19: Study

A team of researchers from different institutions in London, the United States, and Israel, have examined the presence of consistent links between COVID-19 symptoms and SARS-CoV-2 test status in 3 national surveillance platforms.

The researchers intended to determine if inconsistencies could lead to a better understanding and inform future studies as the pandemic progresses, as per the study published in the journal medRxiv*.

Despite differences in surveillance methodology, disease prevalence, and access to testing, loss of sense of smell (anosmia) or loss of taste (ageusia) was consistently found to be the strongest predictor of COVID-19 infection across all platforms over time.

This was based on 658,325 tests (5 per cent positive) from more than 10 million respondents in 3 digital surveillance platforms.

Overall, anosmia (loss of smell) /ageusia (loss of taste) was an order of magnitude more common among those reporting positive (US 43 per cent, UK 44 per cent, Israel 13.9 per cent) compared to negative (US 5 per cent, UK 3 per cent, Israel 0.17 per cent).

“Anosmia/ageusia was, at all times, across all platforms, the symptom with single highest OR for self-reported SARS-CoV-2 test positivity.”

The findings of the study supported the validity of anosmia and ageusia as a reliable symptom of COVID-19, regardless of the surveillance platform used or the testing policy.