Evaluation of the Panbio™ rapid antigen test for COVID-19 diagnosis in symptomatic health care workers

If a health care workers (HCW) experiences COVID-19 associated symptoms, SARS-CoV-2 testing must be performed as soon as possible, to prevent transmission of the virus and to guarantee continuity of care. The gold standard for the detection of SARS-CoV-2, RT-PCR, has a high sensitivity but usually takes 6-8 hours. Lateral flow antigen assays take only 15-30 minutes and do not need any high tech equipment. In a prospective study of our hospital’s HCWs, we evaluated the sensitivity of the Panbio™ COVID-19 Ag Rapid Test (Abbott) against the molecular test Aptima™ SARS-CoV-2 Assay (Hologic) which uses Transcription Mediated Amplification (TMA). TMA positive samples were further subjected to a quantitative real-time SARS-CoV-2 PCR to obtain Ct values as an indication of the viral load. Of 1101 HCWs included in the study between November 2020 and February 2021, 84 (7.6%) were TMA positive, of which 48 (57.1%) were antigen test positive. Most false negative antigen test results occurred if the duration of symptoms had been ≤1 day or ≥7 days. Sensitivities for symptom onset of ≤1, 2 or 3 days were 47.1%, 63.0% and 66.7% respectively. The Panbio™ rapid test is fast and easy to perform, but is not a suitable SARS-CoV-2 test to confirm or exclude COVID-19 in HCWs with a very recent onset of symptoms.