Performance of an Antigen Rapid Test Compared to RT-PCR for the Detection of SARS-CoV-2
Bandar A. Suliman
Department of Medical Laboratory Technology, College of Applied Medical Sciences, Taibah University, Madinah, Kingdom of Saudi Arabia.
Ahmed Aljuhani
Intensive Care Unit, Ohud Hospital, Madinah, Kingdom of Saudi Arabia.
Zuhur Ramadan Almohammadi
Nursing, Ohud Hospital, Madinah, Kingdom of Saudi Arabia.
Yasser A. Abdou
Internal Medicine, Ohud Hospital, Madinah, Kingdom of Saudi Arabia.
Sultan Saud Alahmadi
Family Medicine, Ohud Hospital, Madinah, Kingdom of Saudi Arabia.
Amin Khattab
Ohud Hospital, Madinah, Kingdom of Saudi Arabia.
Mohannad Almikhlafi
Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Madinah, Kingdom of Saudi Arabia.
Hossein M. Elbadawy
*
Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Madinah, Kingdom of Saudi Arabia.
*Author to whom correspondence should be addressed.
Abstract
Background: Rapid and accurate diagnosis of COVID-19 is critical for the management of patients and to limit the spread of the infection. real-time reverse transcription polymerase chain reaction (RT- PCR) is the gold standard for the diagnosis of SARS-CoV-2 infection, however, it is costly and requires time to obtain a result. A number of alternative rapid tests are available now to provide a faster and more convenient solution for the diagnosis of COVID-19. The aim of this work was to compare the performance of a SARS-Cov-2 Antigen Rapid Test (ART) Cassette to the RT-PCR conventional method.
Methods: Two nasopharyngeal swabs were taken from each of the 126 patients included in this study. Of those, 23 were healthy individuals, 9 were confirmed COVID-19 patients and 103 patients from COVID-19 isolation ward in the hospital. For each patient, one sample was processed for RT-PCR and a second swab was used on the ART kit.
Results: Participants were 57.5% males and 42.5% females. The average age was 54.7 (±14). The QPCR swabs returned 67.9% positivity while the antigen rapid test returned 27.4% positivity. In 56.6% of patients the QPCR results concurred with the rapid test results. Using Fagan nomogram analysis, the 95% confidence interval was (2-20) with a negative likelihood of 0.18. Posterior probability was 0.1. Positive test (blue) prior probability was set at 26%. The 95% confidence interval was (31-41) with a positive likelihood of 1.56. Posterior probability was 0.6.
Conclusion: The ART is a useful and efficient test for diagnosing COVID-19, however, QPCR sensitivity is higher. It is recommended to use ART twice for confirming COVID-19 positivity, which will give a statistically more accurate finding.
Keywords: SARS-CoV-2, diagnosis, rapid test, antigen, RT-PCR