Quantitative assessment of olfactory dysfunction accurately detects asymptomatic COVID-19 carriers
Autor
Bhattacharjee, Anindya S.
Joshi, Samir V.
Naik, Shilpa
Sangle, Shashikala
Abraham, Nixon M.
Institución
Resumen
Background: COVID-19 threatens the global community because a large fraction of infected people are
asymptomatic, yet can effectively transmit SARS-CoV-2. Finding and isolating these silent carriers is a crucial
step in confining the spread of the disease. A sudden loss of the sense of smell has been self-reported by
COVID-19 patients across different countries, consistent with expression of the molecular factors mediating
SARS-CoV-2 uptake into human olfactory epithelial supporting cells. However, precise quantification of olfactory loss in asymptomatic COVID-19 carriers is missing to date.
Methods: To quantify olfactory functions in asymptomatic COVID-19 patients, we designed an olfactoryaction meter that determines detectability indices at different odor concentrations and an olfactory matching
accuracy score using monomolecular odors. The optimization of test parameters allowed us to reliably and
accurately assess olfactory deficits in a patient within 20 minutes.
Findings: Measurement of detection indices at low concentrations revealed a 50% reduction in asymptomatic
COVID-19 carriers. Further, patients with better detection scores showed significantly reduced olfactory
matching accuracies compared to normal healthy subjects. Our quantification of olfactory loss, considering
all parameters, identified 82% of the asymptomatic SARS-CoV-2 carriers with olfactory deficits. However, on
subjective evaluation, only 15% of the patients noticed a compromised ability to smell.
Interpretation: Compromised olfactory fitness can serve as a strong basis for identifying asymptomatic
COVID-19 patients. Detailed design specifications and protocols provided here should enable the development of a sensitive, fast, and economical screening strategy that can be administered to large populations to
prevent the rapid spread of COVID-19