Diagnostic Methods (continued)
Type-Specific Serologic Tests
Serologic tests detect type-specific and nonspecific antibodies to HSV that develop during the first several weeks to few months following infection and persist indefinitely.
Type-specific serological tests based on antigens specific for HSV-1 (gG1) and HSV-2 (gG2) have been developed and are now commercially available. Serologic type-specific gG-based assays should be specifically requested when serology is performed, because older assays do not accurately distinguish HSV-1 from HSV-2 antibody. Currently, the FDA-cleared gG-based type-specific assays include the laboratory-based assays: HerpeSelect™-1 or HerpeSelect™-2 ELISA IgG and HerpeSelect™ 1 and 2 Immunoblot IgG (manufactured by Focus Technology, Inc, Herndon, VA); and HSV-2 ELISA (Trinity Biotech USA, Berkeley Heights, NJ).
Two other assays, Biokit HSV-2 and SureVue HSV-2 (Biokit HAS, Lexington, MA and Fisher Scientific, Pittsburgh, PA, respectively), are point-of-care tests that provide results for HSV-2 antibodies from capillary blood or serum during a clinic visit.
The sensitivities of these tests for detection of HSV-2 antibody vary from 80% to 98%, and false-negative results may occur, especially early after infection. The specificities of these assays are ≥ 96%; false-positive results can occur, especially in patients with low likelihood of HSV infection. Therefore, repeat or confirmatory testing (e.g., an immunoblot assay if the initial test was an ELISA) may be indicated in some settings.
Because almost all HSV-2 infections are sexually acquired, type-specific HSV-2 antibody indicates anogenital infection. However, the presence of HSV-1 antibody does not distinguish anogenital from orolabial infection.
Type-specific serologic assays might be useful in the following scenarios:
Page last modified: June 3, 2009
Page last reviewed: June 3, 2009
Content Source: Division of STD Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention