Association of chemosensory dysfunction and COVID-19 in patients presenting with influenza-like symptoms

Abstract

Background: Rapid spread of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and concern for viral transmission by ambulatory patients with minimal to no symptoms underline the importance of identifying early or subclinical symptoms of coronavirus disease 2019 (COVID-19) infection. Two such candidate symptoms include anecdotally reported loss of smell and taste. Understanding the timing and association of smell/taste loss in COVID-19 may help facilitate screening and early isolation of cases.

Methods: A single-institution, cross-sectional study evaluating patient-reported symptoms with a focus on smell and taste was conducted using an internet-based platform on adult subjects who underwent testing for COVID-19. Logistic regression was employed to identify symptoms associated with COVID-19 positivity.

Results: A total of 1480 patients with influenza-like symptoms underwent COVID-19 testing between March 3, 2020, and March 29, 2020. Our study captured 59 of 102 (58%) COVID-19-positive patients and 203 of 1378 (15%) COVID-19-negative patients. Smell and taste loss were reported in 68% (40/59) and 71% (42/59) of COVID-19-positive subjects, respectively, compared to 16% (33/203) and 17% (35/203) of COVID-19-negative patients (p < 0.001). Smell and taste impairment were independently and strongly associated with COVID-19 positivity (anosmia: adjusted odds ratio [aOR] 10.9; 95% CI, 5.08-23.5; ageusia: aOR 10.2; 95% CI, 4.74-22.1), whereas sore throat was associated with COVID-19 negativity (aOR 0.23; 95% CI, 0.11-0.50). Of patients who reported COVID-19-associated loss of smell, 74% (28/38) reported resolution of anosmia with clinical resolution of illness.

Conclusion: In ambulatory individuals with influenza-like symptoms, chemosensory dysfunction was strongly associated with COVID-19 infection and should be considered when screening symptoms. Most will recover chemosensory function within weeks, paralleling resolution of other disease-related symptoms.

Keywords: COVID-19; patient outcomes; smell loss; taste loss.

FIGURE 1

Temporal association of olfactory score and COVID‐19 testing. Spaghetti plot of all COVID‐19–positive individuals (n = 59) reporting olfactory scores (0: no sense of smell, 10: normal sense of smell) at baseline, at time of COVID‐19 diagnosis, and at time of survey completion (post–COVID‐19 diagnosis either <1 week, 1 to 2 weeks, or 2 to 4 weeks). Rows represent time elapsed between testing positive for COVID‐19 and completion of survey. The left and middle columns reflect patient stratification into groups who failed to improve (red lines, left column) and those who achieved improvement/resolution of clinical symptoms (blue lines, middle column) at the time of survey completion. The right column displays aggregated results (mean, SEM) stratified by clinical improvement. COVID‐19 = coronavirus 2019; SEM = standard error of the mean.

FIGURE 2

Temporal association of taste score and COVID‐19 testing. Spaghetti plot of all COVID‐19–positive individuals (n = 59) reporting taste scores (0: no sense of taste, 10: normal sense of taste) at baseline, at time of COVID‐19 diagnosis, and at time of survey completion (post–COVID‐19 diagnosis either <1 week, 1 to 2 weeks, or 2 to 4 weeks). Rows represent time elapsed between testing positive for COVID‐19 and completion of survey. The left and middle columns reflect patient stratification into groups who failed to improve (red lines, left column) and those who achieved improvement/resolution of clinical symptoms (blue lines, middle column) at the time of survey completion. The right column displays aggregated results (mean, SEM) stratified by clinical improvement. COVID‐19 = coronavirus 2019; SEM = standard error of the mean.

FIGURE 3

Temporal relationship between olfactory improvement and clinical improvement following COVID‐19 infection. (A) Histogram demonstrating the reported time to improvement in COVID‐19–positive subjects with olfactory loss and its relationship to patient‐reported time to overall clinical improvement (n = 38, 2 subjects did not answer time to clinical improvement). (B) Histogram demonstrating the time post–COVID‐19 diagnosis (approximate time elapsed since testing positive) in subjects who reported no improvement of smell loss (n = 11); 81.8% were diagnosed <2 weeks prior. COVID‐19 = coronavirus 2019.