Tracking Smell Loss to Identify Healthcare Workers with SARS-CoV-2 Infection

Abstract

Background: Healthcare workers (HCW) treating COVID-19 patients are at high risk for infection and may also spread infection through their contact with vulnerable patients. Smell loss has been associated with SARS-CoV-2 infection, but it is unknown whether monitoring for smell loss can be used to identify asymptomatic infection among high risk individuals, like HCW. Methods: We performed a prospective cohort study, tracking 473 HCW across three months to determine if smell loss could predict SARS-CoV-2 infection in this high-risk group. HCW subjects completed a longitudinal, novel behavioral at-home assessment of smell function with household items, as well as detailed symptom surveys that included a parosmia screening questionnaire, and RT-qPCR testing to identify SARS-CoV-2 infection. Results: SARS-CoV-2 was identified in 17 (3.6%) of 473 HCW. Among the 17 infected HCW, 53% reported smell loss, and were more likely to report smell loss than COVID-negative HCW on both the at-home assessment and the screening questionnaire (P < .01). 67% reported smell loss prior to having a positive SARS-CoV-2 test, and smell loss was reported a median of two days before testing positive. Neurological symptoms were reported more frequently among COVID-positive HCW who reported smell loss (P < .01). Conclusions: In this prospective study of HCW, self-reported changes in smell using two different measures were predictive of COVID-19 infection. Smell loss frequently preceded a positive test and was associated with neurological symptoms.

High Frequency of Smell and Taste Dysfunction in Health Care Professionals With COVID-19 Working in Allergy Departments

“…These results are in line with a Big Data analysis made in Spain, in which it was shown an age-dependent increase in reported cases in both males and females, being patients >79 yrs the most affected. [21] Regarding symptoms upon diagnosis, headache, anosmia, and taste distortion were significantly more frequent in women than men in the before mentioned analysis. In our population, there was less headache reported by older patients.…”

“…[18,19] These differences could be explained because our population is mainly composed of HCP, mostly female, which could constitute a bias, and as it has been previously published, female affected of COVID-19 may be at higher risk to developing SD. [12,15,20,21] In a recent study published in Spain a total of 157/230 (68%) HCP described SD and 161/230 (70%) reported TD, with similar prevalence independently of age or sex. In contrast, in our sample females were significantly more affected than males in terms of STD, as it has been shown in a study using Big Data in Spain.…”

“…In contrast, in our sample females were significantly more affected than males in terms of STD, as it has been shown in a study using Big Data in Spain. [14,21] There are conflicting data with regards STD and gender-predominance, as a recent meta-analysis has found no significant moderation of the prevalence of STD by sex. [22] In contrast, in a multicenter European study, females were, alike our results, significantly more affected by smell and taste dysfunctions than males.…”

The Circadian Clock, the Brain, and COVID-19: The Cases of Olfaction and the Timing of Sleep

“…More importantly, recent studies have now shown that olfactory loss is the best predictor of SARS-CoV-2 infection; indeed, it is potentially superior to other symptoms that the CDC and the World Health Organization (WHO) have determined to be relevant such as fever, cough, headache, and fatigue ( Gerkin et al, 2021 ). Not only is smell loss an early symptom of COVID-19 ( Klopfenstein et al, 2020 ; Levinson et al, 2020 ; Salje et al, 2020 ), olfactory dysfunction has been shown to precede positive polymerase chain reaction (PCR) findings by a median of 2 days ( Weiss et al, 2020 ). Given that to date over 185 million people worldwide have been infected with SARS-CoV-2, daily assessment of olfactory function has enormous public health potential.…”

“…Beyond smell loss per se, Weiss et al (2020) found that parosmia—qualitatively altered olfactory perception where an odor is detected but is perceived unusually and typically as unpleasant—was the first symptom reported in a third of the positive cases where smell dysfunction occurred. Germane to the neurological significance of olfaction in COVID-19, the same study found that all COVID-19 positive individuals who indicated olfactory dysfunction also self-reported neurological symptoms such as headache, dizziness, or fatigue; a small subset of whom experienced prolonged neurological symptoms (≥ 20 days after receiving a positive test).…”