Comparative diagnostic utility of SARS-CoV-2 rapid antigen and molecular testing in a community setting

Kim AE, Bennett JC, Luiten K, O'Hanlon JA, Wolf CR, Magedson A, Han PD, Acker Z, Regelbrugge L, McCaffrey KM, Stone J, Reinhart D, Capodanno BJ, Morse SS, Bedford T, Englund JA, Boeckh M, Starita LM, Uyeki TM, Carone M, Weil A, Chu HY. 2024. J Infect Dis: jiae150.


Background: SARS-CoV-2 antigen-detection rapid diagnostic tests (Ag-RDTs) have become widely utilized but longitudinal characterization of their community-based performance remains incompletely understood.

Methods: This prospective longitudinal study at a large public university in Seattle, WA utilized remote enrollment, online surveys, and self-collected nasal swab specimens to evaluate Ag-RDT performance against real-time reverse transcription polymerase chain reaction (rRT-PCR) in the context of SARS-CoV-2 Omicron. Ag-RDT sensitivity and specificity within 1 day of rRT-PCR were evaluated by symptom status throughout the illness episode and Orf1b cycle threshold (Ct).

Results: From February to December 2022, 5,757 participants reported 17,572 Ag-RDT results and completed 12,674 rRT-PCR tests, of which 995 (7.9%) were rRT-PCR-positive. Overall sensitivity and specificity were 53.0% (95% CI: 49.6–56.4%) and 98.8% (98.5–99.0%), respectively. Sensitivity was comparatively higher for Ag-RDTs used 1 day after rRT-PCR (69.0%), 4 to 7 days post-symptom onset (70.1%), and Orf1b Ct ≤20 (82.7%). Serial Ag-RDT sensitivity increased with repeat testing ≥2 (68.5%) and ≥4 (75.8%) days after an initial Ag-RDT-negative result.

Conclusion: Ag-RDT performance varied by clinical characteristics and temporal testing patterns. Our findings support recommendations for serial testing following an initial Ag-RDT-negative result, especially among recently symptomatic persons or those at high-risk for SARS-CoV-2 infection.