Clinical Epidemiology and Ageing

Self-reported loss of smell without nasal obstruction to identify COVID-19. The multicenter Coranosmia cohort study.

Ceron DSalmon, Bartier S, Hautefort C, Nguyen Y, Nevoux J, Hamel A-L, Camhi Y, Canoui-Poitrine F, Verillaud B, Slama D, Haim-Boukobza S, Sourdeau E, Cantin D, Corré A, Bryn A, Etienne N, Rozenberg F, Layese R, Papon J-F, Béquignon E J Infect. 2020;81(4):614-620.

OBJECTIVES: To determine the frequency of SARS-CoV-2 positive samples in a subset of patients consulting for primarily isolated acute (<7 days) loss of smell and to assess the diagnostic accuracy of olfactory/gustatory dysfunction for COVID-19 diagnosis in the overall population tested for COVID-19 in the same period.

METHODS: Prospective multicentric cohort study in four olfactory ENT units and a screening center for COVID-19.

RESULTS: i) Among a subset of 55 patients consulting for primarily recent loss of smell, we found that 51 (92.7%) had a COVID-19 positive test (median viral load of 28.8 cycle threshold). Loss of smell was mostly total (anosmia), rarely associated with nasal obstruction but associated with a taste disorder in 80%. Olfactory dysfunction occurred suddenly, either as first complaint or preceded by mild symptoms occurring a median of 3 days. The majority of patients (72.9%) partially recovered the sense of smell within 15 days. ii) In a population of 1824 patients tested for COVID-19, the positive predictive value and the specificity of loss of smell and/or taste were 78.5% and 90.3% respectively (sensitivity (40.8%), negative predictive value (63.6%)).

CONCLUSIONS: Self-reported loss of smell had a high predictive positive value to identify COVID-19. Making this sign well known publicly could help to adopt isolation measures and inform potential contacts.

MeSH terms: Adult; Betacoronavirus; Coronavirus Infections; Female; Humans; Male; Olfaction Disorders; Pandemics; Pneumonia, Viral; Prospective Studies; Self Report; Smell; Taste Disorders; Taste Perception
DOI: 10.1016/j.jinf.2020.07.005