Evaluation of Olfactory Acuity in Patients with Coronavirus Disease 2019 (COVID-19)

Abstract

Aim and Objectives To describe the prevalence and characteristics of olfactory dysfunction (OD) in patients with laboratory-confirmed COVID-19 infection. Materials and Methods This monocentric study was performed at Chest Diseases Hospital during the COVID-19 pandemic and all patients testing positive for COVID-19 over a 5-month period (April to August 2020) were recruited. Detailed history was elicited from subjects and all patients were inquired about olfactory dysfunction (OD). Patients with olfactory dysfunction were asked to complete olfactory questionnaires based on the short version of the Questionnaire of Olfactory Disorders-Negative Statements (sQOD-NS). Results 655 patients with mild to moderate COVID-19 infection were included in the study. The prevalence rate of olfactory dysfunction was 18.47% (n = 121) with contribution of 11.60% (n = 76) and 6.87% (n = 45) from anosmia and hyposmia respectively, thereby suggesting olfactory dysfunction to be a significant clinical feature in COVID-19 patients. Males were significantly more affected by olfactory dysfunctions than females. Anosmic patients had significantly reduced sQOD-NS results as compared to hyposmic patients (significant at P \ 0.05). The mean duration of OD was 7.7 days (± 4.3) and [90% patients in our study showed resolution within 14 days. Conclusion The early recognition of olfactory dysfunction should help to screen, identify and thereby quickly isolate mildly symptomatic COVID-19 patients from the general population and the existence of these dysfunctions may well be a prognostic factor in the course of the disease.

Assessing Smell Alteration as Clinical Feature of COVID-19: A Descriptive Study in a Rural Based Tertiary Care COVID Hospital

“…Our study goes in accordance with study of Shah et al 8 who found males are more affected by olfactory dysfunction than females though the prevalence of olfactory dysfunction is only 18.47% (11.6%=anosmia and 6.87%=hyposmia).…”

“…Some studies had also shown lower prevalence. 8 The difference in the results may be due to different geographic and temporal characteristics. COVID patients from Europe and America based countries had higher incidence of olfactory dysfunction.…”

The D614G Virus Mutation Enhances Anosmia in COVID-19 Patients: Evidence from a Systematic Review and Meta-analysis of Studies from South Asia

“…These 40 studies (reporting on 43 cohorts) were subjected to a meta-analysis (Table ). Fifteen studies reported anosmia prevalence in 18 cohorts with a total of 7247 COVID-19 patients from regions where the D614 virus was dominant: three studies from Kuwait or Singapore − and 12 from India or Pakistan. − We compared such data with the results obtained in 25 studies reporting on 25 cohorts with a total of 9626 South Asian patients from the Indian subcontinent (India and Bangladesh) and Oman, when the G614 virus had become dominant (Table , illustrated in Figure A and B). ,− The differences in results between the two types of cohorts are shown in the forest plots (Figure A). The pooled prevalence of olfactory dysfunction in the same ethnicity (South Asians) in regions with D614 predominance was 5.33% (95% confidence interval, CI = 3.52–8.00%), while in regions with G614 predominance, it was 31.79% (95% CI = 23.26–41.76%) (Figure A, C).…”

Prevalence and Recovery from Newly Onset Anosmia and Ageusia in Covid 19 Patients at our Teritary Care Centre

“…In a study conducted by Shah et al [ 35 ] (April–August 2020) by a Total 655 patients, mean age was 32.7 ± 10.1 years with a range of 19–85 years. In their study, 414 (63.20%) patients were males and 241 (36.80%) were females.…”