The Long-Term Effects of COVID-19 on Taste and Smell Dysfunction

A recent study conducted by Shima Moein, MD, PhD, and colleagues found that taste dysfunction was resolved 1 year after exposure to COVID-19, while smell loss persisted for some individuals. The study, published in JAMA Network Open, revealed that 30.3% of individuals with prior COVID-19 experienced olfactory dysfunction, compared to 21% of those who had never been infected with the virus. This sheds light on the long-term impact of COVID-19 on the sensory functions of taste and smell.

Interestingly, the researchers suggested that long-term taste loss after COVID-19 may be attributed to damage to the olfactory epithelium rather than the taste buds themselves. This highlights the complex interplay between taste and smell, and how COVID-19 can disrupt these sensory functions in different ways. The study found that olfactory deficits were more significant in individuals diagnosed with COVID-19 during the early stages of the pandemic when the original untyped and Alpha viral variants were prevalent.

Moein and colleagues recruited participants both with and without a history of COVID-19 from various sources, including social media and bulletin board ads. They utilized the Waterless Empirical Taste Test (WETT) and the University of Pennsylvania Smell Identification Test (UPSIT) to assess taste and smell function in 340 individuals with prior COVID-19 and 434 individuals without a history of the virus. The results showed that taste function did not differ significantly between the two groups, but smell function was lower in those with a history of COVID-19.

The study findings suggest that while most individuals with COVID-19 recover their sense of taste and smell within 2 years, some may experience persistent dysfunction. This underscores the importance of ongoing monitoring and support for individuals who continue to experience sensory deficits long after their initial infection. Moein emphasized the need for greater awareness and support for individuals dealing with smell loss, which has often been overlooked by healthcare professionals and policymakers.

Despite the valuable insights gained from this study, there were limitations that should be taken into consideration. These include the lack of multiple test periods after acute infection and the inability to pinpoint which SARS-CoV-2 variants participants were exposed to. Future research could address these limitations by conducting longitudinal studies and incorporating PCR testing to identify specific variants. This would provide a more comprehensive understanding of the long-term effects of COVID-19 on taste and smell function.

The study conducted by Moein and colleagues sheds light on the enduring impact of COVID-19 on taste and smell dysfunction. By recognizing the complexities of sensory impairment in COVID-19 survivors, healthcare professionals can better support and manage the needs of individuals experiencing persistent sensory deficits. Further research in this area is essential to enhance our understanding of the long-term consequences of COVID-19 on sensory functions and improve care for those affected.