Smell and taste dysfunction during the COVID-19 pandemic: an infodemiological analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection can cause smell and taste dysfunction. We aimed to investigate the general community's interest in smell dysfunction (SD) and taste dysfunction (TD) using Google Trends to compare results with more common symptoms associated with SARS-CoV-2 infection, such as fever and cough.

Relative Search Volumes (RSVs) for the English terms "Smell", "Taste", "Fever" and "Cough", filtered by the category "Health", were collected from 2018 through 2020. Moreover, RSVs using synonyms of "Taste" and "Smell" in 5 European languages were analyzed.

The worldwide mean RSVs for "Fever", "Cough", "Smell", and "Taste" during 2020 were 49%, 34%, 8% and 9%, respectively. RSVs associated with the search terms "Fever" and "Cough" showed a peak between February and March 2020, as did "Smell" and "Taste". Even though RSVs were much lower, they were highly correlated (r=0.890). RSVs obtained from "Smell" and "Taste" in five European languages (German, English, French, Italian and Spanish) had similar temporal trends.

Our findings show the level of the general population's interest for early symptoms, suggesting that their interest in SARS-CoV-2 infection symptoms, such as SD and TD, was scarce but peaked during the pandemic outbreak.