EBOLA Ag K-SeT Rapid Test: Field Evaluation in Sierra Leone

Clin Microbiol Infect. 2018 Jun;24(6):653-657. doi: 10.1016/j.cmi.2017.10.019. Epub 2017 Oct 26.

Abstract

Objectives: Efficient interruption of Ebola virus disease (EVD) transmission chains critically depends on reliable and fast laboratory diagnosis. We evaluated the performance of the EBOLA Virus Antigen Detection K-SeT (EBOLA Ag K-SeT), a new rapid diagnostic antigen test in field settings.

Methods: The study was conducted in a field laboratory located in Freetown (Sierra Leone) by the Italian National Institute for Infectious Diseases 'L. Spallanzani' and the EMERGENCY Onlus NGO. The EBOLA Ag K-SeT was tested on 210 residual plasma samples (EVD prevalence 50%) from patients hospitalized at the EMERGENCY Ebola treatment center in Goderich (Freetown), comparing the results with quantitative real-time PCR.

Results: Overall, the sensitivity of EBOLA Ag K-SeT was 88.6% (95% confidence interval (CI), 82.5-94.7), and the corresponding specificity was 98.1% (95% CI, 95.5-100.7). The positive and negative predictive values were 97.9% (95% CI, 95.0-100.8) and 89.6% (95% CI, 84-95.2), respectively. The sensitivity strongly increased up to 98.7% (95% CI, 96.1-101.2) for those samples with high virus load (≥6.2 log RNA copies/mL).

Conclusions: Our results suggest that EBOLA Ag K-SeT could represent a new effective diagnostic tool for EVD, meeting a need for resource-poor settings and rapid diagnosis for individuals with suspected EVD.

Keywords: Antigen detection; Ebola virus disease; Point of care; Rapid diagnostic test; Western Africa.

MeSH terms

  • Antigens, Viral / immunology*
  • Ebolavirus / immunology*
  • Female
  • Hemorrhagic Fever, Ebola / blood
  • Hemorrhagic Fever, Ebola / diagnosis*
  • Hemorrhagic Fever, Ebola / immunology
  • Hospitalization
  • Humans
  • Male
  • Point-of-Care Systems
  • Reagent Kits, Diagnostic
  • Sensitivity and Specificity
  • Sierra Leone
  • Viral Matrix Proteins / blood*

Substances

  • Antigens, Viral
  • Reagent Kits, Diagnostic
  • VP40 protein, virus
  • Viral Matrix Proteins