An olfactory self-test effectively screens for COVID-19

Research output: Contribution to journalResearch articleContributedpeer-review


  • Kobi Snitz - , Weizmann Institute of Science (Author)
  • Danielle Honigstein - , Weizmann Institute of Science (Author)
  • Reut Weissgross - , Weizmann Institute of Science (Author)
  • Aharon Ravia - , Weizmann Institute of Science (Author)
  • Eva Mishor - , Weizmann Institute of Science (Author)
  • Ofer Perl - , Weizmann Institute of Science (Author)
  • Shiri Karagach - , Weizmann Institute of Science (Author)
  • Abebe Medhanie - , Weizmann Institute of Science (Author)
  • Nir Harel - , Bezalel Academy of Fine Arts and Design (Author)
  • Sagit Shushan - , Weizmann Institute of Science (Author)
  • Yehudah Roth - , Edith Wolfson Medical Center Israel (Author)
  • Behzad Iravani - , Karolinska Institutet (Author)
  • Artin Arshamian - , Karolinska Institutet (Author)
  • Gernot Ernst - , Oslo Metropolitan University (Author)
  • Masako Okamoto - , The University of Tokyo (Author)
  • Cindy Poo - , Champalimaud Research (Author)
  • Niccolò Bonacchi - , Champalimaud Research (Author)
  • Zachary Mainen - , Champalimaud Research (Author)
  • Erminio Monteleone - , University of Florence (Author)
  • Caterina Dinnella - , University of Florence (Author)
  • Sara Spinelli - , University of Florence (Author)
  • Franklin Mariño-Sánchez - , Hospital Ramon y Cajal (Author)
  • Camille Ferdenzi - , INSERM - Institut national de la santé et de la recherche médicale, University of Lyon (Author)
  • Monique Smeets - , Utrecht University (Author)
  • Kazushige Touhara - , The University of Tokyo (Author)
  • Moustafa Bensafi - , INSERM - Institut national de la santé et de la recherche médicale, University of Lyon (Author)
  • Thomas Hummel - , Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Carl Gustav Carus Dresden (Author)
  • Johan N Lundström - , Karolinska Institutet (Author)
  • Noam Sobel - , Weizmann Institute of Science (Author)


Background: Key to curtailing the COVID-19 pandemic are wide-scale screening strategies. An ideal screen is one that would not rely on transporting, distributing, and collecting physical specimens. Given the olfactory impairment associated with COVID-19, we developed a perceptual measure of olfaction that relies on smelling household odorants and rating them online.

Methods: Each participant was instructed to select 5 household items, and rate their perceived odor pleasantness and intensity using an online visual analogue scale. We used this data to assign an olfactory perceptual fingerprint, a value that reflects the perceived difference between odorants. We tested the performance of this real-time tool in a total of 13,484 participants (462 COVID-19 positive) from 134 countries who provided 178,820 perceptual ratings of 60 different household odorants.

Results: We observe that olfactory ratings are indicative of COVID-19 status in a country, significantly correlating with national infection rates over time. More importantly, we observe indicative power at the individual level (79% sensitivity and 87% specificity). Critically, this olfactory screen remains effective in participants with COVID-19 but without symptoms, and in participants with symptoms but without COVID-19.

Conclusions: The current odorant-based olfactory screen adds a component to online symptom-checkers, to potentially provide an added first line of defense that can help fight disease progression at the population level. The data derived from this tool may allow better understanding of the link between COVID-19 and olfaction.


Original languageEnglish
Number of pages12
JournalCommunications medicine
Publication statusPublished - 2022

External IDs

PubMedCentral PMC9053292
unpaywall 10.1038/s43856-022-00095-7
Mendeley 30dc9374-bc0b-33ce-a940-331b777bfe4e
ORCID /0000-0001-9713-0183/work/146645225
Scopus 85144474768


Library keywords