The smell in COVID-19 infection: Diagnostic opportunities

There is a high prevalence of olfaction changes, especially in the early presentation, in coronavirus disease-19 (COVID-19) patients. The mechanisms through which the virus leads to anos-mia/hyposmia are still not fully understood. However, olfaction changes could be used as an indication for testing or quarantine. Screening for infections and other diseases by recognizing volatile organic compounds (VOCs) has been previously conducted. Hence, if the coronavirus infection also results in VOCs excretion, physicians could "smell" the virus by using electronic noses. We conducted a literature review on olfaction changes and the COVID-19. Our results suggest that these changes could be used as an indication for early testing, even as an isolated symptom. We propose that the electronic nose could be used as a future screening tool, especially in agglomeration spaces such as airports, for screening for the COVID-19 infection.