Comparison of diagnostic performance of RT-qPCR, RT-LAMP and IgM/IgG rapid tests for detection of SARS-CoV-2 among healthcare workers in Brazil

J Infect Public Health. 2023 Jul;16(7):1081-1088. doi: 10.1016/j.jiph.2023.05.009. Epub 2023 May 10.

Abstract

Background: COVID-19 has become a major public health problem after the outbreak caused by SARS-CoV-2 virus. Great efforts to contain COVID-19 transmission have been applied worldwide. In this context, accurate and fast diagnosis is essential.

Methods: In this prospective study, we evaluated the clinical performance of three different RNA-based molecular tests - RT-qPCR (Charité protocol), RT-qPCR (CDC (USA) protocol) and RT-LAMP - and one rapid test for detecting anti-SARS-CoV-2 IgM and IgG antibodies.

Results: Our results demonstrate that RT-qPCR using the CDC (USA) protocol is the most accurate diagnostic test among those evaluated, while oro-nasopharyngeal swabs are the most appropriate biological sample. RT-LAMP was the RNA-based molecular test with lowest sensitivity while the serological test presented the lowest sensitivity among all evaluated tests, indicating that the latter test is not a good predictor of disease in the first days after symptoms onset. Additionally, we observed higher viral load in individuals who reported more than 3 symptoms at the baseline. Nevertheless, viral load had not impacted the probability of testing positive for SARS-CoV-2.

Conclusion: Our data indicates that RT-qPCR using the CDC (USA) protocol in oro-nasopharyngeal swabs samples should be the method of choice to diagnosis COVID-19.

Keywords: Accuracy; RT-LAMP; RT-qPCR; SARS-CoV-2; TR DPP® COVID-19 IgM/IgG Bio-Manguinhos.

MeSH terms

  • Brazil / epidemiology
  • COVID-19 Testing
  • COVID-19* / diagnosis
  • Clinical Laboratory Techniques / methods
  • Health Personnel
  • Humans
  • Immunoglobulin G
  • Immunoglobulin M
  • Molecular Diagnostic Techniques
  • Nucleic Acid Amplification Techniques
  • Prospective Studies
  • RNA
  • SARS-CoV-2* / genetics
  • Sensitivity and Specificity

Substances

  • RNA
  • Immunoglobulin G
  • Immunoglobulin M

Supplementary concepts

  • LAMP assay