Julie Walsh-Messinger, University of Dayton assistant professor of psychology, has contributed to a new massive crowdsourced survey of COVID-19 patients from around the world which provides the greatest evidence to date of a link between COVID-19 and the loss of smell, taste and chemesthesis — or sensitivity to chemicals such as those in chili peppers. The findings may have implications for prioritizing the limited supply of COVID-19 tests.

Based on entries from 4,039 participants representing more than 40 countries, the initial findings reveal smell, taste and chemesthesis are significantly reduced in patients diagnosed with COVID-19. Importantly, nasal blockage does not appear to be associated with these losses, suggesting that they may be an important way to distinguish COVID-19 infection from other viral infections, such as cold or flu. 

The findings of this first paper show COVID-19 broadly impacts chemosensory function and disruption in these functions should be considered a possible indicator of COVID-19. The results may give doctors more confidence in recommending telehealth patients for in-person testing while physical distancing remains in place.

Researchers in the Global Consortium for Chemosensory Research launched the survey on April 7 and queried the database 11 days later, on April 18, for the purpose of reporting initial results. The findings appeared on May 8 as a preprint on medrxiv.org. The researchers distributed the questionnaire globally in 10 languages. Responses were crowdsourced through traditional print, television and radio media; social media; flyers; professional networks; and word of mouth.

The survey, however, is still ongoing and Walsh-Messinger urges anyone who recently experienced any respiratory illness, including COVID-19, to go to https://gcchemosensr.org and complete the survey, which is available in 29 languages.

The survey measures self-reported smell and taste in participants who were diagnosed with either an objective test, such as a swab test, or as the result of clinical observations by a medical professional within the two weeks prior to completing the questionnaire.

Participants were asked to quantify their smell and taste, as well as their chemesthetic function — their ability to smell, taste and perceive cooling, tingling and burning sensations in the mouth — before and during the illness. They were also asked to quantify any nasal blockages.

For both diagnosis methods, the authors observed significant quantitative changes in smell, taste and chemesthesis with COVID-19 and can conservatively conclude that a major drop in these chemosensory abilities is a hallmark of COVID-19.

The project is distinct from prior studies on chemosensory skills and COVID-19 in that it leverages a massive crowd-sourced, multinational approach and does so within a collaborative open-science framework.

The GCCR hopes an inclusive globally deployed assessment, coupled with publicly accessible data shared under contemporary open-science best practices, will serve as a foundation for future work.