Coronavirus disease 2019 (COVID‐19)–related smell and taste impairment with widespread diffusion of severe acute respiratory syndrome–coronavirus‐2 (SARS‐CoV‐2) Omicron variant

  1. Paolo Boscolo‐Rizzo
  2. Giancarlo Tirelli
  3. Pierluigi Meloni
  4. Claire Hopkins
  5. Giordano Madeddu
  6. Andrea De Vito
  7. Nicoletta Gardenal
  8. Romina Valentinotti
  9. Margherita Tofanelli
  10. Daniele Borsetto
  11. Jerome R. Lechien
  12. Jerry Polesel
  13. Giacomo De Riu
  14. Luigi Angelo Vaira

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Abstract

Background

The aim of this study was to estimate the prevalence of self‐reported chemosensory dysfunction in a study cohort of subjects who developed a mild‐to‐moderate coronavirus disease 2019 (COVID‐19) in the period from January 17, 2022, to February 4, 2022 (Omicron proxy period) and compared that with a historical series of patients testing positive for severe acute respiratory syndrome–coronavirus‐2 (SARS‐CoV‐2) infection between March and April, 2020 (comparator period).

Methods

Prospective study based on the 22‐item Sino‐Nasal Outcome Tool (SNOT‐22), item “sense of smell or taste” and additional outcomes.

Results

Patients’ characteristics and clinical presentations of COVID‐19 were evaluated and compared in 779 patients, 338 of the study cohort and 441 of the historical series. The prevalence of self‐reported chemosensory dysfunction during the proxy Omicron period (32.5%; 95% confidence interval [CI], 27.6–37.8) was significantly lower from that during the comparator period (66.9%; 95% CI, 62.3–71.3) ( p < 0.001). Nearly one‐quarter of patients (24.6%; 95% CI, 20.1–29.5) reported an altered sense of smell during the proxy Omicron period compared to 62.6% (95% CI, 57.9–67.1) during the comparator period ( p < 0.001). Similarly, the prevalence of an altered sense of taste dropped to 26.9% (95% CI, 22.3–32.0) during the proxy Omicron period from 57.4% (95% CI, 52.6–62.0) during the comparator period ( p < 0.001). The severity of chemosensory dysfunction was lower in the proxy Omicron period compared to the comparator period ( p < 0.001).

Conclusion

The prevalence and the severity of COVID‐19–associated smell and taste dysfunction has dropped significantly with the advent of the Omicron variant but it still remains above 30%.

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  1. Version published to 10.1002/alr.22995
  2. ScreenIT

    SciScore for 10.1101/2022.02.17.22271116: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    EthicsIRB: The study was approved by the Ethics Committees of the Friuli Venezia Giulia Region (CEUR-OS156) and University Hospital of Cagliari (PG 2021/7118).
    Consent: Informed consent was obtained for telephone interviews.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    No key resources detected.

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: We detected the following sentences addressing limitations in the study:
    This study has the following limitations. First, hospitalized patients were not included in the study. Although this made our cohort more homogeneous, studies evaluating the impact of chemosensory dysfunction in more severe Omicron driven COVID-19 are needed. Symptoms were self-reported and based on telephone interview. Although we tried to perform a comprehensive symptoms assessment, some symptoms may have been undetected. Furthermore, a more precise evaluation of the chemosensory function by psychophysical assessment was lacking. Another limitation may be the heterogeneity in the vaccine status across participants. Some of them having one dose of vaccine, while other completed the 3 doses at different times before the conduction of the study. Ultimately, patient inclusion in the proxy omicron period was based on epidemiological data from small samples sequenced regionally. We are therefore unable to estimate to what extent the sample is contaminated by non-Omicron cases. However, to reduce this bias, we decided to limit the analysis to cases of SARS-CoV-2 infection diagnosed after January 17, 2022 when the Omicron variant was estimated to be above 95%.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    About SciScore

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  3. Version published to 10.1101/2022.02.17.22271116v1 on medRxiv