Real-life performance of a COVID-19 rapid antigen detection test targeting the SARS-CoV-2 nucleoprotein for diagnosis of COVID-19 due to the Omicron variant

Abstract

ABSTRACT Objectives It has been suggested that rapid antigen detection assays (RADT) may perform suboptimally in terms of sensitivity for the diagnosis of SARS-CoV-2 Omicron variant infection. To address this issue, we conducted a prospective study in primary health centers to evaluate the clinical performance of the Panbio™ COVID-19 Ag Rapid Test Device in nasopharyngeal specimens (NP) carried out at the point of care. Methods We recruited 244 patients (median age, 40 years; range 2–96; 141 female) with clinical suspicion of COVID-19 (232 adults and 12 children). 228/244 patients had been fully vaccinated (two doses) with licensed COVID-19 vaccines prior to recruitment. Most patients (222/244) were SARS-CoV-2 naïve prior to enrollment. Patients were tested by RT-PCR and RADT within 5 days since symptoms onset. Results 126 patients (51.6%) tested positive by both RT-PCR and RADT, 90 patients (36.8%) returned negative results by both assays and 28 patients (11.4%) yielded discordant results (RT-PCR+/RADT-). No patients tested RT-PCR-/RADT+. Overall specificity and sensitivity of RADT was 100% (95% CI, 95.9–100%) and 81.8% (95% CI, 75–87.1%) respectively. The sensitivity of the assay increased from 79.6% (95% CI, 66.4–88.5) when considering specimens collected at days 0–1 after symptoms onset, to 86.4% (95% CI, 66.7–95.3) when grouping the specimens obtained on days 4–5. Conclusion The Panbio™ COVID-19 Ag Rapid Test Device perform well (≥80% sensitivity) as a point-of-care test for early diagnosis of COVID-19 due to the Omicron variant in primary healthcare centers.