Serologic detection of herpes simplex virus type 2 antibodies among pregnant women using a point-of-care test from Focus Diagnostics

J Clin Virol. 2009 Feb;44(2):125-8. doi: 10.1016/j.jcv.2008.11.009. Epub 2009 Jan 7.

Abstract

Background: Serologic assays that identify herpes simplex type 2 (HSV-2) type-specific antibodies have been commercially available for more than a decade. Greater acceptance of these tests is hindered by uncertainty regarding their performance in real-world clinical settings.

Objectives: The primary objective was to compare the test characteristics of the Focus HerpeSelect Express Assay (EA) versus the Focus HerpeSelect enzyme linked immunoassay (ELISA) for detection of HSV-2 type-specific antibodies among pregnant women enrolled from 3 geographic sites with varying prevalences of HSV-2 infection. A second objective was to evaluate the performance of a HSV-2 testing strategy in which EA screens and ELISA confirms HSV-2 serodiagnosis.

Study design: We enrolled 399 pregnant women from Atlanta, GA, Moorestown, NJ, and Pittsburgh, PA into this cross-sectional investigation. Capillary whole blood was obtained from study participants, and evaluated for the presence of type-specific HSV-2 antibodies using the EA. Serum samples were also obtained from all study participants for subsequent identification of HSV-2 type-specific antibodies using both ELISA and the Focus Immunoblot assays.

Results: We observed 96.2% agreement between results obtained with EA and ELISA. Overall, when compared to ELISA results, the sensitivity of EA for detection of HSV-2 type-specific antibodies was 94.2% and the specificity was 97.1%. Using Immunoblot results as our standard for performance calculations, the positive predictive value (PPV) of HSV-2 serodiagnosis increased from 91.7% to 98.2% when ELISA was used to confirm EA testing.

Conclusions: EA provides similar results to ELISA for the identification of HSV-2 type-specific antibodies among pregnant women. As use of the point-of-care (POC) EA in conjunction with confirmatory ELISA testing improves the PPV of HSV-2 serodiagnosis compared to the use of EA or ELISA testing alone, validation of this diagnostic algorithm in other at-risk populations may be warranted.

Publication types

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

MeSH terms

  • Adolescent
  • Adult
  • Antibodies, Viral / blood*
  • Female
  • Georgia
  • Herpes Genitalis / diagnosis*
  • Herpesvirus 2, Human / immunology*
  • Humans
  • Middle Aged
  • New Jersey
  • Pennsylvania
  • Point-of-Care Systems*
  • Predictive Value of Tests
  • Pregnancy
  • Pregnancy Complications, Infectious / diagnosis*
  • Sensitivity and Specificity
  • Young Adult

Substances

  • Antibodies, Viral