Chemosensation and COVID-19

National Institute On Alcohol Abuse And Alcoholism

Investigators

Linked publications & trials

Abstract

We wrote our clinical protocol for submission to IRB soon. However, through collaborations with other investigators both intramural and extramural we have published a number of manuscripts regarding this topic. The multimodal impact of COVID-19 and the lack of perceived nasal obstruction suggest that severe acute respiratory syndrome coronavirus strain 2 (SARS-CoV-2) infection may disrupt sensory-neural mechanisms. Given our limited understanding of SARS-CoV-2 pathogenesis early in the pandemic, we co-authored a review in Neuron with other members of the Global Consortium for Chemosensory Research (GCCR), where future experiments were proposed to elucidate disease mechanisms, and highlighted the relevance of this ongoing work to understanding how the virus may alter brain function more broadly. As these symptoms continued to be reported, we wrote a commentary led by Dr. Rosario Jaime-Lara (postdoctoral fellow) in Allergy and Rhinology describing the role of olfaction in human health with a focus on coronaviruses. To date as many as 80% or more of patients infected with SARS-CoV-2 report anosmia, hyposmia, ageusia, dysgeusia, or changes in chemesthesis. Self-reported changes in chemosensory perception can predict whether a patient will test positive for SARS-CoV-2. Many of the early chemosensory and COVID-19 studies lacked objective chemosensory assessment, raising the possibility that chemosensory disturbances are even more prevalent than currently appreciated. Together with Dr. Danielle Reed (Monell Chemical Senses Center), we published a systematic review and meta-analysis. In this analysis, we reported that objective measures were a more sensitive method to identify smell loss because of infection with SARS-CoV-2. Of note, the use of subjective measures, while expedient during the early stages of the pandemic, underestimated the true prevalence of smell loss. In a second preregistered, cross-sectional study that used a crowdsourced questionnaire in 23 languages to assess symptoms in individuals self-reporting recent respiratory illness, we showed that smell loss is the best predictor of symptomatic COVID-19 infection. We found that smell loss during illness was the best predictor of symptomatic COVID-19 infection in both single and cumulative feature models (ROC AUC=0.72), with additional features providing no significant model improvement. We were not able to predict any other outcome (e.g., severity, hospitalization, ICU hospitalization) since we did not ask about hospitalization in that first survey. With this data in hand, we developed the ODoR-19 tool, a 0-10 scale to screen for recent olfactory loss currently being validated in clinical populations by others. Given the lab's interest in chemosensation and obesity as well as the knowledge that individuals with obesity show alterations in smell and taste abilities, we conducted a secondary analysis using data from the GCCR. We compared self-reported chemosensory ability in participants with a respiratory illness reporting a positive (C19+; n = 5156) or a negative (C19-; n = 659) COVID-19 laboratory test outcome, who self-reported to be obese (C19+; n = 433, C19-; n = 86) or non-obese. We found that compared to the C19- group, C19+ exhibited a greater decline in smell, taste, and chemesthesis during illness, though these symptoms did not differ between participants with obesity and without obesity. In 68% of participants who reported recovery from respiratory illness symptoms (n=3431 C19+ and n= 539 C19-), post-recovery chemosensory perception did not differ in C19+ and C19- diagnosis, and by self-reported obesity. We conclude that despite a presumed lower sensitivity to chemosensory stimuli, COVID-19 respondents with obesity experience a similar self-reported chemosensory loss as those without obesity, and in both groups self-reported chemosensory symptoms are similarly predictive of COVID-19. Intramurally, as discussed, We established collaborations during the COVID-19 pandemic. Patients with AUD are at higher risk of COVID-19. We began to evaluate the data collected in the natural history COVID-19 impact alcohol study led by Drs. Ramchandani and Diazgranados.