Simple Disposable Odor Identification Tests for Predicting SARS-CoV-2 Positivity.

Laura Ziuzia-Januszewska,Paweł Dobrzyński,Jaromir Ciszek,Waldemar Wierzba,Krzysztof Ślączka,Łukasz Krawiec,Artur Zaczyński

doi:10.3390/ijerph181910185

Abstract

Olfactory dysfunction (OD) is a common manifestation of COVID-19 and may be useful for screening. Survey-based olfactory evaluation tends to underestimate the prevalence of OD, while psychophysical olfactory testing during a pandemic has the disadvantage of being time consuming, expensive, and requiring standardized laboratory settings. We aimed to develop a quick, simple, affordable, and reliable test to objectively assess the prevalence and diagnostic accuracy of OD in COVID-19. The olfactory function of 64 COVID-19 inpatients and 34 controls was evaluated using a questionnaire and a simple disposable odor identification test (SDOIT) developed for this study. Four SDOIT models were assessed: 10-SDOIT, 9-SDOIT, 8-SDOIT, and 4-SDOIT, with 10, 9, 8 and 4 samples, respectively. We found a high frequency of self-reported OD in COVID-19 patients, with 32.8% and 42.2% reporting current and recent OD, respectively. Different SDOIT models revealed smell impairment in 54.7–64.1% of COVID-19 patients. The combination of either 10-SDOIT results and self-reported OD, or 8-SDOIT results and self-reported OD, were the best predictors of COVID-19, both with an AUC value of 0.87 (0.85 and 0.86 for the age-matched subjects). OD is a common symptom of COVID-19. A combination of self-reported smell deterioration and OD psychophysically evaluated using SDOIT appears to be a good predictor of COVID-19.

Highlights

A growing body of evidence shows a high incidence of olfactory dysfunction (OD)in coronavirus disease 2019 (COVID-19), with prevalence ranging from 5 to 98.3% [1,2,3,4,5,6,7].it has been hypothesized that new-onset smell impairment could serve as a potential predictor of SARS-CoV-2 infection [8,9].Most of the previous studies on OD in COVID-19 are survey-based
Using a simple disposable odor identification test (SDOIT) we found that, there was a significant correlation between self-reported smell impairment and the psychophysical test results, OD was more frequently revealed by psychophysical evaluation
We suggest than when there is enough time and a satisfactory availability of RT-PCR assay, one should consider the combination of self-reported OD and 10-SDOIT; with limited time and resources, the combination of 8-SDOIT and self-reported OD seems to be adequate as a predictor of SARS-CoV-2 positivity and an indication for RT-PCR testing

Summary

Introduction

Most of the previous studies on OD in COVID-19 are survey-based. Selfassessment of OD tends to underestimate its true prevalence due to recall bias and subjects not being aware of their smell impairment [2,10], especially while experiencing other, severe symptoms such as respiratory distress [11]. Moein et al [2] found that 98% of COVID-19 patients exhibited OD when assessed objectively, compared with only 28% selfreporting smell deterioration. In a study by Vaira et al [12], objective evaluation revealed mild hyposmia in 30.3% of subjectively normosmic patients. Several meta-analyses showed a higher overall prevalence of OD when using objective compared with subjective assessment methods (72.1–77% vs 44.5–53%, respectively) [11,13,14]

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Discussion

Conclusion