Low performance of rapid antigen detection test as frontline testing for COVID-19 diagnosis

Scohy, Anaïs; Anantharajah, Ahalieyah; Bodéus, Monique; Kabamba-Mukadi, Benoît; Verroken, Alexia; Rodriguez-Villalobos, Hector

BACKGROUND: Ensuring accurate diagnosis is essential to limit the spread of the SARS-CoV-2 and for the clinical management of COVID-19. Although real-time reverse transcription polymerase chain reaction (RT- qPCR) is the current recommended laboratory method to diagnose SARS-CoV-2 acute infection, several factors such as requirement of special equipment and skilled staff limit the use of these time-consuming molecular techniques. Recently, several easy to perform rapid antigen detection tests were developed and recommended in some countries as the first line of diagnostic. OBJECTIVES: The aim of this study was to evaluate the performances of the Coris COVID-19 Ag Respi-Strip. Study design. We performed a comparison study by testing nasopharyngeal samples with RT-qPCR and antigen rapid test. RESULTS: 148 nasopharyngeal swabs were tested. Amongst the 106 positive RT-qPCR samples, 32 were detected by the rapid antigen test, given an overall sensitivity of 30.2%. All the samples detected positive with the antigen rapid tests were also positive with RT-qPCR. CONCLUSIONS: Highest viral load is associated with better antigen detection rates. Unfortunately, the overall poor sensitivity of the COVID-19 Ag Respi-Strip does not allow using it alone as the frontline testing for COVID-19 diagnosis.