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[Preprint]. 2020 Jun 17:2020.06.15.20132134.
doi: 10.1101/2020.06.15.20132134.

Prevalence of Chemosensory Dysfunction in COVID-19 Patients: A Systematic Review and Meta-analysis Reveals Significant Ethnic Differences

Christopher S von Bartheld  1 , Molly M Hagen  2 , Rafal Butowt  3
Affiliations

Prevalence of Chemosensory Dysfunction in COVID-19 Patients: A Systematic Review and Meta-analysis Reveals Significant Ethnic Differences

Christopher S von Bartheld et al. medRxiv. .

Update in

Abstract

A significant fraction of people who test positive for COVID-19 have chemosensory deficits. However, the reported prevalence of these deficits in smell and/or taste varies widely, and the reason for the differences between studies is unclear. We determined the pooled prevalence of such chemosensory deficits in a systematic review. We searched the COVID-19 portfolio of the National Institutes of Health for all studies that reported the prevalence of smell and/or taste deficits in patients diagnosed with COVID-19. Forty-two studies reporting on 23,353 patients qualified and were subjected to a systematic review and meta-analysis. Estimated random prevalence of olfactory dysfunction was 38.5%, of taste dysfunction was 30.4% and of overall chemosensory dysfunction was 50.2%. We examined the effects of age, disease severity, and ethnicity on chemosensory dysfunction. The effect of age did not reach significance, but anosmia/hypogeusia decreased with disease severity, and ethnicity was highly significant: Caucasians had a 3-6 times higher prevalence of chemosensory deficits than East Asians. The finding of ethnic differences points to genetic, ethnicity-specific differences of the virus-binding entry proteins in the olfactory epithelium and taste buds as the most likely explanation, with major implications for infectivity, diagnosis and management of the COVID-19 pandemic.

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Conflict of interest statement

Conflicts of Interests

The authors have declared no competing interests.

None of the authors have any proprietary interests or conflicts of interest related to this submission.

Figures

Figure 1.
Figure 1.
Figure 2.
Figure 2.
Funnel Plots of the prevalence of dysfunction of smell (A), taste (B), and smell and/or taste (C) in COVID-19 patients. Each dot represents a single study with the x-axis showing the logit transformed proportion of people in each study that lost their sense of (A) smell, (B) taste, and (C) smell and/or taste; the y-axis shows the standard error.
Figure 3.
Figure 3.
Forest plots of the prevalence of smell dysfunction (A), taste dysfunction (B), and smell and/or taste dysfunction (C) in COVID-19 patients. Estimated random proportions are shown by red boxes with 95% confidence intervals (95% CI) extending as whiskers, the overall estimated random proportion of subgroups is shown in gray, and the results for all studies combined are shown in black. Note the difference between East Asians and Caucasians.
Figure 4.
Figure 4.
World Map of the Prevalence of any Chemosensory Deficit in COVID-19 Patients
Figure 5
Figure 5
Estimated random prevalence of chemosensory dysfunction in COVID-19 patients, based on ethnicity with 95% confidence intervals from meta-analysis. Note the significant difference between Caucasians and East Asians.
Figure 6
Figure 6
Bubble plots of subgroup tests for relationships between disease severity (the percentage of hospitalized patients) in each cohort and loss of smell (A), taste (B), and loss of smell and/or taste (C). Patients who are hospitalized (have more severe disease) report fewer chemosensory deficits.
See this image and copyright information in PMC

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