A recent study published in JAMA Network Open on April 23, 2024, revealed that nearly one-third of individuals who had previously been infected with Covid-19 experienced some degree of smell loss one year post-exposure. The study, which included 340 participants, found that taste function was not significantly altered one year after Covid-19 infection, with a lack of taste loss reported. However, a significant proportion of individuals continued to experience olfactory dysfunction, a common symptom of long Covid.
The researchers also noted that more recent SARS-CoV-2 variants, such as Omicron, exhibited less frequent smell loss compared to earlier variants. A 2023 study published in Rhinology found that the prevalence of smell loss among those infected with the Omicron variant was significantly lower than that of individuals infected with the original Covid-19 variant, Alpha variant, and Delta variant. These findings suggest that the impact of Covid-19 on sensory functions may vary depending on the viral variant.
In the United States, an estimated 10 to 35 million adults of working age are living with post-Covid condition, also known as long Covid. This condition encompasses a range of health problems that can be new, recurring, or persistent. Understanding the prevalence of individual symptoms, such as smell and taste loss, is crucial for providing support to survivors of Covid-19 and addressing their needs effectively.
Participants in the study were recruited from the United States through advertisements on Reddit and local bulletin boards. The study included 434 healthy participants without a history of Covid-19 infection and 340 patients who had previously been infected. Tests involving flavor identification using plastic taste strips and odorant identification using microcapsules were conducted to assess participants’ sensory abilities.
The researchers found that individuals with a history of Covid-19 were more likely to experience smell loss compared to those without such a history. The incidence of partial or full loss of smell was also higher in the group with a Covid-19 history. Test scores for participants with the original and Alpha variant infections differed significantly from those without a Covid-19 history. These findings highlight the long-term impact of Covid-19 on sensory functions and the variability in symptoms across different viral variants.
Overall, the study emphasizes the importance of understanding the long-term consequences of Covid-19, particularly in terms of sensory function. By identifying and addressing symptoms such as smell loss, researchers can better support individuals living with post-Covid condition and improve their quality of life. Further research is needed to explore the relationship between viral variants and sensory symptoms, as well as to develop targeted interventions for individuals experiencing long-term effects of Covid-19.
