Background: Herpes simplex virus (HSV)-type specific serology (TSS) testing has been commercially available for nearly a decade. Guidelines on appropriate use of such testing exist, including Canadian-based recommendations. Despite this, most Canadian laboratories do not offer HSV-type specific serology and many provide only nontype-specific HSV serology tests.
Methods: At the Alberta Provincial Laboratory, HSV TSS is performed using the following algorithm (termed the Alberta algorithm). Eligible specimens are first tested with a nontype-specific kit (Behring Enzygnost IgG). If positive, sera are then tested using the Focus HerpeSelect-2 assay to establish HSV-2 infection. If the HerpeSelect-2 result is negative, the result is reported as anti-HSV-1 positive. In this study we sought a validation of the Alberta algorithm by testing 344 serum samples with the Behring Enzygnost IgG assay, the type specific Focus HerpeSelect 1 and 2 assays, and by Western blot (WB).
Results: Taking the WB as a gold standard, the Behring Enzygnost IgG assay showed a sensitivity of 94% and a specificity of 100%, whereas the Alberta algorithm had a sensitivity of 92% and a specificity of 97% for the detection of HSV-2 antibodies, and a sensitivity of 94% and a specificity of 100% for the detection of HSV-1 antibodies in HSV-2 negative sera. Focus HerpeSelect 1 and HerpeSelect 2 sensitivities against WB were 88% and 91%, whereas specificities were 95% and 97% for HSV-1 and HSV-2, respectively.
Conclusions: The Alberta algorithm was at least equivalent to HerpeSelect 1 and 2 in detecting anti-HSV antibodies. Although sensitivity and specificity were higher, the differences were not statistically significant.