Epidemiology and Prognosis of Hepatic Encephalopathy at Zinder National Hospital

Abstract

Introduction: Antigen rapid diagnosis tests are an alternative to molecular tests for SARS-CoV-2 detection in a context of limited resources. This study aimed to assess the performance of two Ag RDTs compared to the genes detected by RT-PCR.

Methods: This study was conducted during the COVID-19 pandemic from January to May 2021 at the Institut de Recherche en Sciences de la Santé, Burkina Faso. A total of 156 samples were collected, of which 86 tested positive and 70 negative by RT-PCR. It consisted of a technical evaluation of two antigenic rapid diagnostic tests, Standard^TM Q COVID-19 Ag and Standard^TM F COVID-19 Ag FIA, compared to the FastPlex^TM SARS-CoV-2 detection RT-PCR.

Results: The number of positives detected with each Ag RDT is higher for a single gene than for the two genes detected by RT-PCR (31 vs. 18 and 26 vs. 19). In the presence of two genes (ORF1ab and N), both Ag RDTs are less sensitive (43.9% and 46.3%) than when RT-PCR detects a single ORF1ab or N gene (68.9% and 57.8%). For each Ag RDT, the most positives were detected for samples with high viral loads (Ct<29). Although sensitivities are low, the sensitivity of each Ag RDT is better for higher viral loads.

Conclusion: This study showed a poor performance of the two RDTs, especially in comparative sensitivity and when the RT-PCR detected two genes. Their use should be limited in the context of the high endemicity of COVID-19 and samples with low viral load.