Unmasking the ‘Asymptomatic’ COVID-19: A Nose Question

Abstract

The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus has high infectivity, often masked by asymptomatic carriers, which allows it to spread rapidly and become a pandemic. Attempts to slow the pandemic at this stage depend on the ability to unmask asymptomatic carriers. The rapid diagnosis of active coronavirus disease 2019 (COVID-19) infection is one of the cornerstones of pandemic control, as the nasal cavity is the main gateway for SARS-CoV-2 entry and altered sense of smell is a feature of the current virus. In the present study, we therefore tested the olfactory threshold coupled with heart–lung parameters in subjects undergoing traditional molecular testing, resulting in a significantly different score between asymptomatic subjects and healthy controls. In total, 82% of asymptomatic positives showed olfactory impairment; of these, 46% had severe hyposmia and 7% had anosmia, while in the control 9% had severe hyposmia and 0% had anosmia, respectively, which agrees with heart rate, breathing rate, and blood pressure parameter variations. The olfactory test coupled with physiological parameters may help to identify asymptomatic people. In conclusion, our results suggest that most asymptomatic individuals could be unmasked by mass olfactory rapid threshold screening and then referred to traditional slower diagnostic tests.

Analysis of COVID-19 Incidence and Protective Potential of Persisting IgG Class Antibodies against SARS-CoV-2 Infection in Hospital Staff in Poland

“…In contrast, in our study population of healthcare workers, COVID-19 was confirmed in 4% of individuals in April–May 2020, and in June 2020, IgG class anti-SARS-CoV-2 antibodies were detected in over 7.5% of subjects. This seems to confirm the literature data, pointing to significant proportions of low symptomatic or asymptomatic cases or cases with atypical symptoms among people with COVID-19 who spread the infection easily and unnoticed [ 43 ]. The large proportion of asymptomatic cases significantly biased both the perception of the real extent of SARS-CoV-2 circulation in the Polish population and estimations of the infection/fatality ratio [ 44 ].…”

“…This finding confirms the importance of the problem of the people, often called non-responders [ 46 , 47 ], who do not produce antibodies after contact with SARS-CoV-2 antigens. Alternatively, this may be explained by a rapid decrease in initially achieved antibody levels to values below lab detection limits in a significant percentage of the population [ 43 ]. The ability of the immune system to protect against a severe course of the disease and the response of these people to standard COVID-19 vaccinations remain to be determined.…”

Post-Viral Olfactory Loss: What We Learned from the SARS-CoV-2 Pandemic

“…The reviews by Scotto et al [60] and Pang et al [61] analyze the correlations between taste alterations and SARS-CoV-2 establishing the diagnostic value of this chemosensitive disorder. The diagnostic value of olfactory disorders is instead the subject of studies by Mazzatenta et al [62,63] and Jungbauer et al [64].…”