What do we know about smell and taste dysfunction by SARS-CoV-2. Predictive Value of the Venezuelan Olfactory test and RT-PCR analysis in viral infection diagnosis

Background Smell and taste disorders are reported very frequently and at an early stage in the evolution of the infectious disease caused by the SARS-CoV-2. These symptoms could be sensitive and specific to establish the condition of the infection, and may suggest the flow of decisions as to further therapy. We asked whether smell and taste impairment are earlier and more sensitive symptoms than the RT-PCR molecular assays for SARS-CoV-2 detection. Methodology Subjects (N=275) with a probable COVID19 diagnosis were classified as follows: Symptomatic with chemosensory dysfunction, symptomatic without chemosensory dysfunction, and asymptomatic. Subjects received a general clinical and otorhinolaryngology examination. Evaluation of the chemosensory dysfunction was performed by means of the Venezuelan Olfactory Test and taste test. Nasal swabs and blood samples were analyzed by real-time polymerase chain reaction analysis (RT-PCR) and a rapid diagnostic test to detect the SARS-CoV-2 virus and antiviral antibodies, respectively. Patients had access to molecular tests and smell and taste evaluations every 3 to 5 days until they recovered. Results Out of 44 patients that were positive for RT-PCR SARS-CoV-2: 45.83% had smell and taste disorders and COVID19 symptoms, 23.61% did not have smell or taste disorders, but had COVID19 symptoms, and 30.55% were asymptomatic. Mild hyposmia and hypogeusia account for the most frequent chemosensory disorders accompanying common SARS-CoV-2 symptoms. Time to recover from the chemosensory dysfunction ranges from 3 to 14 days, up to a maximum of 5 weeks, while RT-PCR becomes negative after 21 days and up to 35 days in some cases. The Venezuelan Olfactory Test and taste test has a 61.68% positive predictive value, 45.83% sensitivity, and 68.7% specificity for SARS-CoV-2 infection. Conclusions Smell and taste disorders are frequent symptoms of SARS-CoV-2 infection, but not a significant predictor of the disease, as compared to the molecular RT-PCR test. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement MPPS of Venezuelan ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: Collection and analysis of data were approved by the Bioethical committee of the Carlos Arvelo University Military Hospital of Caracas. All studies were conducted in compliance with the Declaration of Helsinki, and all participants signed an informed consent. The current study included participants for which there was full information on multiple SARS-CoV-2 measures and key outcomes, including psychosocial factors, chronic medical conditions, and socio-demographic factors. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Available