Affected olfaction in COVID-19: Re-defining “asymptomatic”

It has been reported that olfactory dysfunction (OD) is a premonitory symptom of COVID-19 in various populations [1-3], and may persist even in recovered patients [4]. These data suggest that OD may be a reliable symptom of COVID-19. Therefore, the rapid and accurate identification of olfactory impairment is positioned to enhance early COVID-19 diagnosis for timely and preventive intervention. In their article entitled “Quantitative assessment of olfactory dysfunction accurately detects asymptomatic COVID-19 carriers” published in EClinicalMedicine, Anindya Bhattacharjee et al. introduced a novel tool to quantify olfactory deficits in asymptomatic COVID-19 patients [5]. Their quantitative assessment of olfactory dysfunction as described is novel, economical, convenient, and has a high sensitivity. Furthermore, it can be applied for large-scale COVID-19 screening, especially among asymptomatic carriers. COVID-19 asymptomatic carriers are patients with a positive nucleic acid result but without common clinical symptoms such as fever and chest imaging manifestations. Asymptomatic carriers are currently diagnosed by using nucleic acid testing kits, which are regarded as the gold standard for the diagnosis. However, laboratory detection may be time-consuming and requires rigorous laboratory specifications. Furthermore, due to the limited sensitivity of the molecular testing kits, false-negative results cannot be avoided, increasing the difficulty to contain this disease. However, as reported by Anindya Bhattacharjee et al., the current diagnosis can be further assisted by this novel approach, allowing earlier health management and minimizing further transmission.