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


OBJECTIVE
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.


METHODS
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.
Leyland
Bridget
B
Magee-Womens Research Institute, Pittsburgh, PA 15213, USA.
Kennedy
Margaret R
MR
Wimberly
Yolanda H
YH
Levine
Bruce J
BJ
Cherpes
Thomas L
TL
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood*; D005260:Female; D005845:Georgia; D006558:Herpes Genitalis / Q000175:diagnosis*; D018258:Herpesvirus 2, Human / Q000276:immunology*; D006801:Humans; D008875:Middle Aged; D009515:New Jersey; D010414:Pennsylvania; D019095:Point-of-Care Systems; D011237:Predictive Value of Tests; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000175:diagnosis*; D012680:Sensitivity and Specificity; D055815:Young Adult
D000914:Antibodies, Viral