Coronavirus disease 2019 (COVID-19) is a disease caused by the SARS-CoV-2 virus. Although many people that contract COVID-19 remain asymptomatic, they may still transmit the virus. Therefore, it is important to identify these carriers to help prevent the spread of the disease. This study aimed to assess loss of smell and olfactory dysfunction in asymptomatic carriers, and to establish a precise method to quantify these parameters. The authors recorded detection in response to ten odorants at varying concentrations in normal healthy subjects and asymptomatic COVID-19 patients.