Long-Term Taste and Smell Outcomes After COVID-19

Area of Science:

• Neuroscience
• Infectious Diseases
• Public Health

Background:

• Self-reported taste deficits are common after SARS-CoV-2 infection, impacting quality of life.
• However, self-reports may inaccurately reflect olfactory dysfunction rather than true taste system pathology.
• Quantitative taste testing is crucial to understand post-COVID-19 taste function.

Purpose of the Study:

• To investigate the association between COVID-19 and long-term taste and smell function using validated psychophysical tests.
• To objectively assess taste and smell outcomes in individuals with and without a history of COVID-19.

Main Methods:

• A nationwide cross-sectional study involving individuals with and without prior COVID-19 history.
• Utilized the Waterless Empirical Taste Test (WETT) and University of Pennsylvania Smell Identification Test (UPSIT) for sensory assessments.
• Analyzed taste and smell scores using statistical methods including analysis of covariance and chi-squared tests.

Main Results:

• No significant difference in taste scores was observed between individuals with and without a history of COVID-19 (P=.94).
• Individuals with prior COVID-19 had significantly lower smell identification scores (P<.001), with 30.3% experiencing dysfunction.
• Earlier SARS-CoV-2 variants (untyped and Alpha) were associated with greater smell loss compared to later variants.

Conclusions:

• Objective taste dysfunction was not evident one year after COVID-19 exposure.
• Persistent smell loss in a significant portion of individuals may explain perceived taste complaints.
• Early SARS-CoV-2 variants were linked to more severe olfactory deficits.