Microbiology Spectrum (Jun 2023)

Regional Evaluation of Two SARS-CoV-2 Antigen Rapid Diagnostic Tests in East Africa

  • Muna Affara,
  • Hakim Idris Lagu,
  • Emmanuel Achol,
  • Neema Omari,
  • Grace Ochido,
  • Eric Kezakarayagwa,
  • Francine Kabatesi,
  • Cassien Nduwimana,
  • Anatole Nkeshimana,
  • Donald Duku Samson,
  • Gwokpan Awin Nykwec,
  • Joseph Daniel Wani Lako,
  • Michael Lasuba,
  • Lul Lojok Deng,
  • Maria Ezekiely Kelly,
  • Peter Bernard Mtesigwa Mkama,
  • Alex Magesa,
  • Salum Said Ali,
  • Sabra Amour Rashid,
  • Godfrey Pimundu,
  • Tonny Muyigi,
  • Susan Ndidde Nabadda,
  • Robert Rutayisire,
  • Alice Kabanda,
  • Emmanuel Kabalisa,
  • Jürgen May,
  • Eric Nzeyimana,
  • Michael Katende,
  • Florian Gehre

DOI
https://doi.org/10.1128/spectrum.04895-22
Journal volume & issue
Vol. 11, no. 3

Abstract

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ABSTRACT The clinical performance of two rapid antigen tests for the diagnosis of Severe Acute Respiratory Coronavirus (SARS-CoV-2) were regionally evaluated in East African populations. Swabs were collected from 1,432 individuals from five Partner States of the East African Community (Tanzania, Uganda, Burundi, Rwanda and South Sudan). The two rapid antigen tests (Bionote NowCheck COVID-19 Ag and SD Biosensor STANDARD Q COVID-19 Ag) were evaluated against the detection of SARS-CoV-2 RNA by the Reverse Transcription PCR (RT-PCR) gold standard. Of the concordant results with both RT-PCR and rapid antigen test data (862 for Bionote and 852 for SD Biosensor), overall clinical sensitivity was 60% and 50% for the Bionote NowCheck and the SD Biosensor STANDARD Q, respectively. Stratification by viral load, including samples with RT-PCR cycle thresholds (Ct) of 80%, as defined by the WHO. Therefore, the rapid antigen test alone should not be used for diagnosis but could be used as part of an algorithm to identify potentially infectious individuals with high viral load. IMPORTANCE Accurate diagnostic tests are essential to both support the management and containment of outbreaks, as well as inform appropriate patient care. In the case of the SARS-CoV-2 pandemic, antigen Rapid Diagnostic Tests (Ag-RDTs) played a major role in this function, enabling widespread testing by untrained individuals, both at home and within health facilities. In East Africa, a number of SARS-CoV-2 Ag-RDTs are available; however, there remains little information on their true test performance within the region, in the hands of the health workers routinely carrying out SARS-CoV-2 diagnostics. This study contributes test performance data for two commonly used SARS-CoV-2 Ag-RDTs in East Africa, which will help inform the use of these RDTs within the region.

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