Utility of Olfactory test as screening tool for COVID 19: A pilot study

Loss of smell function (Anosmia) is reported to be associated with novel coronavirus disease 2019 (COVID-19) infection. The present study was designed to evaluate the effectiveness of an indigenously developed prototype smell test to identify/diagnose asymptomatic COVID-19 positive individuals. A panel of five different odorants belonging to Indian household with unique and mutually exclusive odor were used to develop prototype kit to test the hypothesis. The developed prototype kit was tested at 2 centers (N = 49 and 34) with slight modifications. Simultaneously, the kit was also tested on 55 (N = 35 and 20) healthy controls. Our results indicate that otherwise asymptomatic COVID-19 positive individuals were having quantifiable deficit in smell sensation. Interestingly, the variable sensitivity of different odorants was observed in different patients. None of the healthy controls reported difficulty in sensing any of the odorant, whereas, some of healthy controls did misidentify the odorants. Overall, the present study provides a preliminary data that loss in smell sensation for various odorants can be exploited as a quick and affordable screening test to identify infected cases among at risk individuals. ### Competing Interest Statement The authors have declared no competing interest. ### Clinical Trial CTRI Reg. No. CTRI/2020/05/025487 ### Clinical Protocols ### Funding Statement Authors have acknowledged the funding support from National Agri-Food Biotechnology Institute (NABI), Department of Biotechnology, Ministry of Science and technology, Govt. of India. ### 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: Institute Ethics committee, Post Graduate Institute of Medical Education and Research (PGIMER), Chandigarh, India All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived.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 Relevant data is included in the article. There is no such data from this work that need submission in repositories.