ABSTRACT
Aim The project aims to examine chemosensory dysfunction in long-COVID with a focus on olfactory function about 9 months after SARS-CoV-II-infection. Material and Methods In this population-based cross sectional study, PCR-confirmed SARS-CoV-2 outpatients were examined between November and June 2020 at Kiel university hospital. Data on medical history and chemosensory function were collected via questionnaires and a Visual Analogue Scale (VAS), olfactory performance was psychophysically objectified using the Sniffin' Sticks test. Results A total of 376 female and 290 male patients were included with a mean age of 48.2 years ranging from 19 to 87 years. The mean follow-up was 9.09 months (range 1.64-15.18) after initial positive PCR-testing. The prevalence for olfactory dysfunction (OD) during infection was 66,1 %. 33,7 % of the subjects reported persistent OD subjectively at the time of examination (female 28,8 %, male 42,3 %). T-test analysis showed a significant decline of reported olfactory evaluation from before COVID-19 to the time of examination based on VAS (p < 0.001). 34,6 % of the subjects were tested hyposmic or anosmic by Sniffin' Sticks. A significant correlation was shown between a subjective estimation of OD by the patients and an objectively tested OD (p < 0.001). The TDI-score correlated positively with the amount of time (in months) that passed since PCR-testing (p < 0.001). Discussion OD in SARS-CoV-II-infection is frequent and can be persistent long beyond the acute phase of ilness. We demonstrated that anamnestic OD is significantly related to psychophysically tested OD. Therefore one can conclude that a subjective OD is a likely predictor of an actual objective OD. Furthermore, OD shows a tendency to improve over time.
ABSTRACT
Background This study aims to investigate the prevalence and long-term development of gustatory dysfunction (GD) after COVID-19. Methods In the population-based cross-sectional COVIDOM-study, 667 patients above the age of 18 years (mean 48.2) who tested positive for SARSCoV- 2 via PCR-testing on average 9.09 months ago were examined between November 2020 and June 2021. Extensive medical history taking was conducted via questionnaires. Participants were asked to rate their ability to taste before, during and after COVID-19 on a Visual Analogue Scale (VAS) ranging from 0 to 10. Whole mouth gustatory testing with Taste Strips for the qualities sweet, sour, salty, and bitter was performed. Results 60.9 % (406 of 667) participants reported gustatory impairment during their infection. Out of those, 56.9 % perceived this symptom as severe and 13.3 % noticed it as the earliest symptom. At the time of our examination, 36.2 % had a persistent subjective GD, defined as a lower score on the VAS than before COVID-19 (mean difference -0.9 points). This difference was significant (p < 0.001). In the testing, 7.3 % (47 of 667) participants had a GD, defined as the correct identification of less than three out of four Taste Strips. No signifi- cant correlation was found between subjectively persistent and tested GD (p = 0.250). Conclusions SARS-CoV-2 seems to frequently affect the gustatory function in the long term as well, what might have an influence on patients' everyday-life. However, Patients' own perception does not always correspond with psychophysiological testing which might be caused by the common difficulty to differentiate between the chemosensory senses of taste and smell.