Nasopharyngeal Panbio COVID-19 Antigen Performed at Point-of-Care Has a High Sensitivity in Symptomatic and Asymptomatic Patients With Higher Risk for Transmission and Older Age. (2nd February 2021)

• Record Type: Journal Article
• Authors: Masiá, Mar; Fernández-González, Marta; Sánchez, Manuel; Carvajal, Mar; García, José Alberto; Gonzalo-Jiménez, Nieves; Ortiz de la Tabla, Victoria; Agulló, Vanesa; Candela, Inmaculada; Guijarro, Jorge; Gutiérrez, José Antonio; de Gregorio, Carlos; Gutiérrez, Félix
• Is Part Of: Open forum infectious diseases. Volume 8:Number 3(2021)
• Publication Date: 2021-02-02
• Subjects: antigen -- COVID-19 -- Panbio -- point-of-care -- SARS-CoV-2; Communicable diseases -- Periodicals; Medical microbiology -- Periodicals; Infection -- Periodicals; 616.9
• DOI: 10.1093/ofid/ofab059
• Languages: English
• ISSNs: 2328-8957

Abstract

Abstract: Background: Performance of point-of-care tests in different clinical scenarios and on different samples remains undetermined. We comprehensively evaluated the performance of the nasopharyngeal Panbio COVID-19 Ag Rapid Test Device. Methods: This is a prospective study that includes consecutive patients attending 3 primary care centers (PCCs) and an emergency department. The antigen test was performed at point-of-care in nasopharyngeal and nasal swabs and in saliva. Positive percent agreement (PPA) and negative percent agreement (NPA) were calculated with the reverse-transcription polymerase chain reaction (RT-PCR) assay as reference standard. Results: Of 913 patients included, 296 (32.3%) were asymptomatic and 690 (75.6%) came from the PCC. Nasopharyngeal swabs were collected from 913 patients, nasal swabs were collected from 659 patients, and saliva was collected from 611 patients. The RT-PCR was positive in 196 (21.5%) nasopharyngeal samples (NPS). Overall, PPA (95% CI) in NPS was 60.5% (53.3–67.4), and it was lower in nasal swabs (44.7%) and saliva (23.1%). Test performance in NPS was largely dependent on the cycle threshold (Ct) in RT-PCR, with PPA of 94% for Ct ≤25 and 80% for Ct <30. In symptomatic patients, the PPA was 95% for Ct ≤25, 85% for Ct <30, and 89% for the symptom triad of fever, cough, and malaise. Performance was also dependent on age, with a PPA of 100% in symptomatic patients >50 years with Ct <25. In asymptomatic patients, the PPA was 86% for Ct <25. In all cases, NPA was 100%. Conclusions: The nasopharyngeal Panbio COVID-19 Ag test performed at point-of-care has a good sensitivity in symptomatic patients with Ct <30 and older age. The test was useful to identify asymptomatic patients with lower Ct values. Abstract : The nasopharyngeal Panbio-COVID-19 Ag test performed in real-life conditions at point-of-care is highly sensitive in symptomatic patients, particularly with Ct <30 and older age. The test is useful to identify asymptomatic patients with lower Ct values.