Prospective study of three saliva qualitative antigen testing kits for the detection of SARS-CoV-2 among mainly symptomatic patients in Japan

This is the authors' abstract. We don't add key points for this paper.

INTRODUCTION: Rapid qualitative antigen testing has been widely used for the laboratory diagnosis of COVID-19 with nasopharyngeal samples. Saliva samples have been used as alternative samples, but the analytical performance of those samples for qualitative antigen testing has not been sufficiently evaluated. METHODS: A prospective observational study evaluated the analytical performance of three In Vitro Diagnostics (IVD) approved COVID-19 rapid antigen detection kits for saliva between June 2022 and July 2022 in Japan using real-time reverse transcription polymerase chain reaction (RT-qPCR) as a reference. A nasopharyngeal sample and a saliva sample were simultaneously obtained, and RT-qPCR was performed. RESULTS: copies/mL). CONCLUSION: COVID-19 rapid antigen detection kits with saliva showed high specificity, but the sensitivity varied among kits, and were also insufficient for the detection of symptomatic COVID-19 patients.