Evaluation of the Biofire FilmArray BioThreat-E Test (v2.5) for Rapid Identification of Ebola Virus Disease in Heat-Treated Blood Samples Obtained in Sierra Leone and the United Kingdom

J Clin Microbiol. 2016 Jan;54(1):114-9. doi: 10.1128/JCM.02287-15. Epub 2015 Nov 4.

Abstract

Rapid Ebola virus (EBOV) detection is crucial for appropriate patient management and care. The performance of the FilmArray BioThreat-E test (v2.5) using whole-blood samples was evaluated in Sierra Leone and the United Kingdom and was compared with results generated by a real-time Ebola Zaire PCR reference method. Samples were tested in diagnostic laboratories upon availability, included successive samples from individual patients, and were heat treated to facilitate EBOV inactivation prior to PCR. The BioThreat-E test had a sensitivity of 84% (confidence interval [CI], 64% to 95%) and a specificity of 89% (CI, 73% to 97%) in Sierra Leone (n = 60; 44 patients) and a sensitivity of 75% (CI, 19% to 99%) and a specificity of 100% (CI, 97% to 100%) in the United Kingdom (n = 108; 70 patients) compared to the reference real-time PCR. Statistical analysis (Fisher's exact test) indicated there was no significant difference between the methods at the 99% confidence level in either country. In 9 discrepant results (5 real-time PCR positives and BioThreat-E test negatives and 4 real-time PCR negatives and BioThreat-E test positives), the majority (n = 8) were obtained from samples with an observed or probable low viral load. The FilmArray BioThreat-E test (v2.5) therefore provides an attractive option for laboratories (either in austere field settings or in countries with an advanced technological infrastructure) which do not routinely offer an EBOV diagnostic capability.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Blood / virology*
  • Ebolavirus / genetics
  • Ebolavirus / isolation & purification*
  • Hemorrhagic Fever, Ebola / diagnosis*
  • Hemorrhagic Fever, Ebola / virology
  • Hot Temperature
  • Humans
  • Molecular Diagnostic Techniques / methods*
  • Sensitivity and Specificity
  • Sierra Leone
  • Specimen Handling / methods*
  • Time Factors
  • United Kingdom

Grant support

This study was funded by the United Kingdom Ministry of Defence and Public Health England. The Kerry Town, Sierra Leone, evaluation was performed in the Ebola Treatment Centre laboratory, funded by the United Kingdom Department for International Development.