Emerging reports suggest that new onset of smell or taste loss are potential early clinical markers of SARS-CoV-2 infection, but it remains unclear as to what extent.
Therefore, the purpose of this study is to systematically assess the prevalence of self-reported altered sense of smell or taste in patients with confirmed SARS-CoV-2 infection, overcoming the limitations of individual studies by meta-analysis of pooled data.
The databases Medline, Embase, Web of Science, Scopus and MedRxiv's set were searched from inception to the 4th May 2020.
This study was conducted following the PRISMA checklist.
18 studies met the eligibility criteria out of the 171 initially screened citations. The overall prevalence of alteration of the sense of smell or taste was 47% , but estimates were 31% and 67% in severe and mild-to-moderate symptomatic patients, respectively.
The loss of smell and taste preceded other symptoms in 20% of cases and it was concomitant in 28%.