Recovery of flavor perception and umami taste sensitivity in young Chinese adults following SARS-CoV-2 Omicron infection: a case-control series

SARS-CoV-2, particularly the Omicron variant, often leads to flavor perception dysfunction in infected individuals, making a comprehensive understanding of its duration and recovery patterns a critical part of disease management. This study surveyed a cohort of 199 mildly-to-moderately affected SARS-CoV-2 Omicron-infected patients, focusing on the alterations in their olfaction, taste, and chemesthesis perception. Further, a subset of 36 participants (18 healthy and 18 infected) underwent sensory evaluations to check the variation of umami taste sensitivity. The results demonstrated that most of the infected cohort experienced chemosensory disorders, with the recovery period varying between one week and over a month. Intriguingly, the severity of flavor perception changes during infection significantly correlated with the length of the recovery period. Furthermore, this study explored the specific manifestations of flavor perception dysfunction, potential contributing factors, and potential mechanistic explanations for chemosensory disorders. These include local damage, inflammatory responses, and virus-induced neural damage. However, this study revealed no significant change (P > 0.05) in umami taste sensitivity among infected patients 55 days post-infection. While this research faces limitations related to its self-reported, cross-sectional design, and regional focus, it offers valuable insights into the multifaceted impact of COVID-19, particularly the Omicron variant, on chemosensory perception.