Real-life evaluation of a rapid antigen test (DPP SARS-CoV-2 Antigen) for COVID-19 diagnosis of primary healthcare patients, in the context of the Omicron-dominant wave in Brazil. (March 2023)

• Record Type: Journal Article
• Authors: Bezerra, Matheus Filgueira; Silva, Lilian Caroliny Amorim; Pessoa-e-Silva, Rômulo; Soares, Gisele Lino; Dezordi, Filipe Zimmer; Lima, Gustavo Barbosa; Lima, Raul Emídio; Campos, Tulio L.; Docena, Cassia; Oliveira, Anderson Bruno; Pitta, Maira Galdino da Rocha; Santos, Francisco de Assis da Silva; Pereira, Michelly; Wallau, Gabriel Luz; Paiva, Marcelo Henrique Santos
• Is Part Of: Clinical microbiology and infection. Volume 29:Number 3(2023)
• Page Start: 392.e1
• Page End: 392.e5
• Publication Date: 2023-03
• Subjects: COVID-19 diagnosis -- Evidence-based -- Omicron -- Rapid antigen test -- Viral control; Medical microbiology -- Periodicals; Diagnostic microbiology -- Periodicals; Communicable diseases -- Periodicals; Infection -- Periodicals; 616.01
• DOI: 10.1016/j.cmi.2022.11.003
• Languages: English
• ISSNs: 1198-743X

Abstract

Abstract: Objectives: We aimed to investigate the real-life performance of the rapid antigen test in the context of a primary healthcare setting, including symptomatic and asymptomatic individuals that sought diagnosis during an Omicron infection wave. Methods: We prospectively accessed the performance of the DPP SARS-CoV-2 Antigen test in the context of an Omicron-dominant real-life setting. We evaluated 347 unselected individuals (all-comers) from a public testing centre in Brazil, performing the rapid antigen test diagnosis at point-of-care with fresh samples. The combinatory result from two distinct real-time quantitative PCR (RT-qPCR) methods was employed as a reference and 13 samples with discordant PCR results were excluded. Results: The assessment of the rapid test in 67 PCR-positive and 265 negative samples revealed an overall sensitivity of 80.5% (CI 95% = 69.1%–89.2%), specificity of 99.2% (CI 95% = 97.3%–99.1%) and positive/negative predictive values higher than 95%. However, we observed that the sensitivity was dependent on the viral load (sensitivity in Ct < 31 = 93.7%, CI = 82.8%–98.7%; Ct > 31 = 47.4%, CI = 24.4%–71.1%). The positive samples evaluated in the study were Omicron (BA.1/BA.1.1) by whole-genome sequencing (n = 40) and multiplex RT-qPCR (n = 17). Conclusions: Altogether, the data obtained from a real-life prospective cohort supports that the rapid antigen test sensitivity for Omicron remains high and underscores the reliability of the test for COVID-19 diagnosis in settings with high disease prevalence and limited PCR testing capability. Graphical abstract: Image 1