Analytical sensitivity and clinical sensitivity of the three rapid antigen detection kits for detection of SARS-CoV-2 virus

Background: Numerous rapid antigen detection (RAD) kits for diagnosing COVID-19 patients are available in the market recently. Objective: To compare analytical sensitivity and clinical sensitivity for the three commercially available RAD kits. Study Design: Analytical sensitivity for the detection of SARS-CoV-2 virus was determined by limit of detection (LOD) using RT-PCR as a reference method. Clinical sensitivity was evaluated by using respiratory specimens collected from confirmed COVID-19 patients. Results: The LOD results showed that the three RAD kits varied from 102-105 fold less sensitive than RT-PCR. Clinical sensitivity of RAD kits ranged from 22.9 %-71.4 % for detecting specimens from COVID-19 patients. Conclusions: Although RAD kits were less sensitive than RT-PCR, understanding the clinical characteristics of different RAD kits can guide us to obtain suitable specimens for testing. The likelihood of positive results for RAD kits will be higher.