ABSTRACT
The current COVID-19 pandemic requires the use of safe olfactory testing protocols that can be applied on a large scale. To this end, we developed the Chemosensory Perception Test (CPT), a quick test carried out at home to objectify olfactory and gustatory complaints. Specifically, it assesses orthonasal and retronasal olfaction as well as gustation using common North American household items. This study aims to compare the CPT scores with the participants' initial olfactory complaint and with standardized testing. We hypothesized CPT scores to be significantly lower in participants having a subjective and/or objective olfactory dysfunction (OD). Participants were tested using the CPT and the University of Pennsylvania Smell Identification Test (UPSIT). They were divided in two groups according to initial olfactory complaint or UPSIT score. CPT olfactory scores (average orthonasal and retronasal scores) were compared between groups using t-tests;association between CPT and UPSIT scores was analyzed with Pearson's correlation coefficient. We obtained preliminary results from 26 participants: 15 participants (57.7%) had subjective OD and 14 participants (53.8%) showed objective OD according to UPSIT. Average CPT orthonasal (9.3 vs 6.3;t(17.888)=5.594, p<0.001) and retronasal (9.6 vs 6.1;t(15.842)=3.985, p=0.001) scores were significantly lower in participants who identified themselves as having OD. However, we did not find any significant difference when groups were divided into normosmia/ microsmia according to the UPSIT. Nevertheless, average CPT orthonasal (r=0.461, p=0.018) but not retronasal scores were correlated with UPSIT scores. Our results suggest that the CPT is consistent with subjective and objective OD and can be used in the current context, especially in longitudinal study designs.
ABSTRACT
Objective: To evaluate COVID-19-related persistent chemosensory dysfunction (CD) in a cohort of Quebec healthcare workers. Background: CD is now recognized as a major symptom of COVID-19. While published studies have investigated and quantified persistent CD in up to 20% of patients, very few have examined the duration, severity and trajectory of chemosensory impairments in patients with persisting CD. Design/Methods: We conducted a cross-sectional observational study in a cohort of over 800 healthcare workers who received a positive diagnosis for SARS-CoV-2 with a nasopharyngeal viral swab, recruited through the Quebec National Institute of Public Health, 4 months after diagnosis. We used an online 64-item questionnaire examining self-evaluated olfactory, gustatory and trigeminal impairments as well as clinical and epidemiological consequences of the infection which includes a previously validated CD-home test (CD-HT). As part of the questionnaire, both smell and taste were evaluated on a scale from 0 to 10 (0: No perception;10: Very strong perception). Results: 813 respondents (women: 84.1%) answered the questionnaire on average 150.1 (SD: 31.1) days post-diagnosis. Average self-reported smell ratings were 8.98 (1.62) pre-infection, 2.85 (3.74) during the acute phase and 7.41 (2.46) when the respondents answered the questionnaire. These numbers were 9.20 (1.34), 3.59 (3.67), and 8.05 (2.20) for taste. In 458 respondents who indicated a compromised sense of smell during the acute phase, average smell rating at the time they answered the questionnaire was 6.89 (2.52) compared to 9.03 (1.61) before the infection.297 (51.2%) of them reported not regaining olfactory functions at the time of testing;when assessed with the CD-HT, 134 of 810 respondents (18.4%) have persistent loss of smell. No significant sex differences were observed in acute or persistent smell loss. Conclusions: CD persists in a significant number of COVID-19 patients. Long-term follow-up and in-laboratory chemosensory examinations are required to assess the extent of the associated impairments.