key: cord-349311-yo4up42r
authors: De Maria, Andrea; Varese, Paola; Dentone, Chiara; Barisione, Emanuela; Bassetti, Matteo
title: High prevalence of olfactory and taste disorder during SARS‐CoV‐2 infection in outpatients
date: 2020-05-17
journal: J Med Virol
DOI: 10.1002/jmv.25995
sha: 
doc_id: 349311
cord_uid: yo4up42r

Prevalent symptoms of SARS-CoV-2 in reports and metaanalyses refer to cough, fatigue, myalgia and respiratory distress. These represent clinically acknowledged relevant findings of valuable importance, particularly with the requirement for ventilation and hospital bed occupancy in ICUs. There is however a wide discordance with the actual picture of clinical presentation and symptoms in Italy. Here we comment on Sun and coll Metaanlysis with particular nuance to olfactory and taste disorders that very often herald SARS-CoV-2 in our country, particularly in outpatients, and are not reported so far in the medical literature from China. This article is protected by copyright. All rights reserved.

To the Editor,

We read with interest the meta-analysis by Sun et al and their conclusion on the most prevalent symptoms based on 10 reports weighted prevalently on Chinese patients. 1 The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) epidemic initiated in China in December 2019 has drawn relevant attention to respiratory symptoms and to clinical pictures dominated by severe respiratory engagement leading to noninvasive and invasive ventilation. 2,3 After

China, Italy has experienced the second wave of epidemic spread and also has a high case-fatality rate attributed to multiple factors. 4 In their report, the authors align with the vast majority of reports from the far East conveying the notion that coronavirus disease 2019 (COVID-19) is predominantly related to respiratory symptoms thus confirming the need for preparedness to respiratory support/ intensive care unit. 5, 6 We note, however, that this analysis is based exclusively on hospitalized patients, which only represent a minor proportion (about 20%) of all infected symptomatic patients, and may thus represent a relevant bias. Limited or no information has been so far gathered on the majority of milder cases of SARS-CoV-2-disease that are cared for at home since they are not progressing to respiratory insufficiency and hospitalization/ventilation.

In addition, profound olfactory and taste disorder (OTD), that has been reported to be frequent in hospitalized patients in Italy, 7 is not reported in China or other areas, 2,3,5 and correspondingly fails to be reported in the meta-analysis. 1 To investigate OTD in outpatients, a questionnaire was administered at our institute to physicians caring for patients with COVID-19 at home. A total of 95 patients have been observed independently (Table 1 ). Patients had been followed up in five different independent areas, without epidemiological relationship. All had confirmed SARS-CoV-2 infection as determined by nasopharyngeal swab polymerase chain reaction (NFS), had mild symptomatic disease with fever and without respiratory distress nor need for hospitalization/respiratory oxygen support.

Notably, 48 of 95 (50.5%) patients had extensive taste disorder (>8 on a 10-grade Likert scale) and had an associated self-assessed olfactory dysfunction compared to their experience before onset of fever and COVID-19 symptoms (grade > 6, Likert scale) ( Table 1) .

ODT was reported to occur very early on during disease (within 5 days from the onset of fever). All patients reported loss of taste to the otherwise lively variety of regional Italian dishes. In all cases, Reasons underlying failure to report this clinical picture so far may include failure to detect, recognize or report these signs, different population genetics of chemosensors, or differences in regional cuisine habits. SARS-CoV-2 infection determines a surprisingly high and widespread incidence of OTD which appears to be pathognomonic. This high frequency of ODT can be used to help identify SARS-CoV-2 outpatient cases without respiratory involvement in western countries.

For these reasons, we suggest that meta-analyses that are performed on exclusively hospitalized populations with patient selection 

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Investigation of three clusters of COVID-19 in Singapore: implications for surveillance and response measures

Epidemiologic features and clinical course of patients infected with SARS-CoV-2 in Singapore

Self-reported olfactory and taste disorders in SARS-CoV-2 patients: a cross-sectional study

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