Performance of an alternative RT-PCR procedure using residual sample from the Panbio

• Published in: The Brazilian journal of infectious diseases 2021-09, Vol.25 (5), p.1
• Main Authors: Melo, Mayla Gabryele Miranda De, Galliez, Rafael Mello, Faffe, Debora Souza, Mariani, Diana, Tanuri, Amilcar, Castineiras, Terezinha Marta Pereira Pinto, Leitao, Isabela De Carvalho, Nascimento, Erica Ramos Dos Santos, Ferreira, Orlando Costa
• Format: Article
• Language: English
• Subjects: Polymerase chain reaction
• ISSN: 1413-8670

Introduction: In the current standard of care (SoC) RT-PCR method for COVID-19, the patient's swab was extracted in viral transport media (VTM). For the Panbio[TM] COVID-19 Ag Rapid Test, the patient swab is flushed out in extraction buffer, of which a small fraction is used for testing, leaving more than half the sample unused. This study was designed to show that RT-PCR results from the residual sample of the Panbio[TM] COVID-19 Ag Rapid Test (called Novel RT-PCR) are not worse than the SoC RT-PCR result. Methods: The study was performed using (1) dilution series of five patient samples, and (2) 413 patient samples comparing SOC versus Novel RT-PCR results. Results: For the dilution series samples, all tested positive by both methods. The bias between Ct values of Novel RT-PCR and SoC RT-PCR did not exceed 3.00 Ct using primers N1 and N2. A total of 413 COVID symptomatic patients seeking COVID testing were tested, of which 89 patients tested positive and 324 tested negative with SoC RT-PCR. In 324 patients who tested negative with SoC RT-PCR, 323 tested negative with Novel RT-PCR, and one (1) tested positive. Out of 89 who tested positive with SoC RT-PCR, 80 tested positive with the Novel RT-PCR, and nine patients showed a negative test result. The Overall Percent Agreement for the 413 valid patient sample pairs was 97.5 [95% CI 97 to 98]. Conclusion: The study demonstrated that the performance of the Novel RT-PCR method is acceptable compared to the SoC RT-PCR method and can be a useful tool to perform RT-PCR without the need for new swab collections. Keywords: COVID-19 Antigen rapid test RT-PCR