Chemosensory dysfunctions induced by COVID-19 can persist up to 7 months: A study of over 700 healthcare workers

  1. Nicholas Bussière
  2. Jie Mei
  3. Cindy Lévesque-Boissonneault
  4. Mathieu Blais
  5. Sara Carazo
  6. Francois Gros-Louis
  7. Gaston De Serres
  8. Nicolas Dupré
  9. Johannes Frasnelli

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Abstract

Several studies have revealed either self-reported chemosensory alterations in large groups or objective quantified chemosensory impairments in smaller populations of patients diagnosed with COVID-19. However, due to the great variability in published results regarding COVID-19-induced chemosensory impairments and their follow-up, prognosis for chemosensory functions in patients with such complaints remains unclear. Our objective is to describe the various chemosensory alterations associated with COVID-19 and their prevalence and evolution after infection. A cross-sectional study of 704 healthcare workers with a RT-PCR confirmed SARS-CoV-2 infection between 28/2/2020 and 14/6/2020 was conducted 3 to 7 months after onset of symptoms. Data were collected with an online questionnaire. Outcomes included differences in reported chemosensory self-assessment of olfactory, gustatory, and trigeminal functions across time points and Chemosensory Perception Test scores from an easy-to-use at-home self-administered chemosensory test. Among the 704 participants, 593 (84.2%) were women, the mean (SD) age was 42 (12) years, and the questionnaire was answered on average 4.8 (0.8) months after COVID-19. During COVID-19, a decrease in olfactory, gustatory, and trigeminal sensitivities were reported by 81.3%, 81.5% and 48.0% respectively. Three to seven months later, reduced sensitivity was still reported by 52.0%, 41.9% and 23.3% respectively. Chemosensory Perception Test scores indicate that 19.5% of participants had objective olfactory impairment. These data suggest a significant proportion of COVID-19 cases have persistent chemosensory impairments at 3 to 7 months after their infection but the majority of those who had completely lost their olfactory, gustatory, and trigeminal sensitivity have improved.

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  1. Version published to 10.1101/2021.06.28.21259639v3 on medRxiv
  2. Version published to 10.1101/2021.06.28.21259639v2 on medRxiv
  3. ScreenIT

    SciScore for 10.1101/2021.06.28.21259639: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: Study Design: This study was reviewed and approved by the research ethics board of the CHU de Québec – Université Laval (MP-20-2021-5228) and all protocols were reviewed by an independent Scientific Review Committee.
    Consent: All participants provided an online informed consent prior to participation.
    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:
    Limitations: Given the cross-sectional design of the study, a recall bias is possible for all self-reported peri-SARS-CoV-2 infection values before or during the SARS-CoV-2 infection due to the 3-to-7-month gap. This study did not control for potential confounding factors like race and level of education. Finally, the CPT requires further validation for its gustatory and trigeminal components, and it relies on substances found in participants’ homes, which may lead to variation in test results due to the differences in the brand, quality, or expiration date of substances and consequently, their ability to trigger equal sensorineural responses.

    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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  4. Version published to 10.1101/2021.06.28.21259639v1 on medRxiv
  5. Version published to 10.1093/chemse/bjab038