Abstract

BACKGROUND: Variable prevalence of smell and taste dysfunction caused by SARS-CoV-2 infection has been reported worldwide1,2. Although South American countries have been listed in the top ten of COVID-19 case numbers3,4, psychophysical data has not been reported in these regions. This study aimed primarily, to determine the frequency of self-perceived taste impairment and smell measurement in COVID-19 patients, and secondly, to assess its association with the need for hospitalization. METHODS:Prospective cohort study conducted during April-October 2020, approved by our Institutional Scientific Ethics Committee. Cases: Adults with a positive SARS-CoV-2 quantitative real-time polymerase chain reaction (qRT-PCR) and <15 days of ongoing symptoms. A chemosensory symptoms survey for self-reported olfactory and gustatory dysfunction and the Spanish-American version of the 40-odorant UPSIT (Sensonics International, Haddon Hts., NJ)5 were applied during the recruitment process (initial UPSIT [iUPSIT]) and repeated 30 days after symptom onset (follow-up UPSIT [fUPSIT]). Controls: Individuals without SARS-CoV-2 infection with negative qRT-PCR, IgM-IgG for SARS-CoV-2, and asymptomatic 14 days after, paired by age and sex. An UPSIT was applied in this group, to compare olfactory dysfunction prevalence in healthy subjects against cases. RESULTS: One hundred COVID-19 patients were enrolled (56 outpatients, 44 hospitalized). Five were lost during follow-up (1 transferred to ICU and 4 withdrew). Sixty-three controls were included. Demographics in both groups were similar. At enrollment, smell loss was self-identified in 73/100(73%) cases and was perceived at 3.4±1.9 days since symptom onset. At follow-up, 23/94(24.4%) persisted with olfactory dysfunction. Dysgeusia was self-perceived in 51/100(51%) at enrollment. Outpatients presented dysgeusia more frequently than hospitalized individuals (36/56 [64%] vs. 15/44 [34%]; x2=8.99; p=0.002). At follow-up, dysgeusia decreased to 24/95 (25.2%). anosmia and odynophagia had a protective OR, while older age and a higher iUPSIT score were associated with a greater risk for hospitalization. CONCLUSION SARS-CoV-2 induced disease produces a prevalent but highly reversible olfactory and taste dysfunction. Age and better olfactory function are associated with a greater risk for hospitalization, while odynophagia, as a symptom of COVID-19, appears to be a protective factor.