Objective screening for olfactory and gustatory dysfunction during the COVID-19 pandemic: a prospective study in healthcare workers using self-administered testing

Abstract

Background: Smell and taste loss are highly prevalent symptoms in coronavirus disease 2019 (COVID-19), although few studies have employed objective measures to quantify these symptoms, especially dysgeusia. Reports of unrecognized anosmia in COVID-19 patients suggests that self-reported measures are insufficient for capturing patients with chemosensory dysfunction.

Objectives: The purpose of this study was to quantify the impact of recent COVID-19 infection on chemosensory function and demonstrate the use of at-home objective smell and taste testing in an at-risk population of healthcare workers.

Methods: Two hundred and fifty healthcare workers were screened for possible loss of smell and taste using online surveys. Self-administered smell and taste tests were mailed to respondents meeting criteria for elevated risk of infection, and one-month follow-up surveys were completed.

Results: Among subjects with prior SARS-CoV-2 infection, 73% reported symptoms of olfactory and/or gustatory dysfunction. Self-reported smell and taste loss were both strong predictors of COVID-19 positivity. Subjects with evidence of recent SARS-CoV-2 infection (<45 days) had significantly lower olfactory scores but equivalent gustatory scores compared to other subjects. There was a time-dependent increase in smell scores but not in taste scores among subjects with prior infection and chemosensory symptoms. The overall infection rate was 4.4%, with 2.5% reported by PCR swab.

Conclusion: Healthcare workers with recent SARS-CoV-2 infection had reduced olfaction and normal gustation on self-administered objective testing compared to those without infection. Rates of infection and chemosensory symptoms in our cohort of healthcare workers reflect those of the general public.

Keywords: Anosmia; Brief Smell Identification Test; COVID-19; Chemosensory dysfunction; Dysgeusia; Gustation; Healthcare workers; Objective testing; Olfaction; Screening; University of Pennsylvania Smell Identification Test.

Figure 1

Study design.

Figure 2

B‐SIT scores (A) and SA‐WETT® scores (B) compared to onset of chemosensory dysfunction in patients with swab‐confirmed SARS‐CoV‐2 infection or positive antibody test with COVID‐19 symptoms. Logarithmic regression model with 95% confidence interval is plotted, with (A) P = 0.02 and R² = 0.61, and (B) P = 0.68 and R² = 0.04.

Figure 3

B‐SIT scores (A) and SA‐WETT® scores (B) by COVID‐19 status. One‐way ANOVA demonstrated significance for B‐SIT scores (P < 0.001) but not for SA‐WETT® scores (P = 0.85). Key: “No Infection” = negative swab or antibody test before or during study; “Recent Infection” = positive swab <45 days prior to smell/taste testing, or positive antibody test with symptoms <45 days prior to smell/taste testing; “Remote Infection” = positive swab >45 days prior to smell/taste testing, or positive antibody test with no symptoms or symptoms >45 days prior to smell/taste testing. Error bars represent 95% confidence intervals.