What does a positive Herpes Simplex Virus (HSV) type 2 Immunoglobulin G (IgG) antibody test result indicate?

Significance of Positive HSV Type 2 IgG Antibody

A positive HSV-2 IgG antibody test indicates established latent infection with herpes simplex virus type 2, which typically causes genital herpes, though confirmation may be needed for low positive results (index values <3.0) due to test specificity limitations. 1

Interpretation of Positive HSV-2 IgG Results

• A positive HSV-2 IgG antibody test indicates past exposure and ongoing latent infection with HSV-2, with antibodies persisting indefinitely after infection 1
• The test does not distinguish between recent and long-standing infections, as both type-specific IgG antibodies develop within several weeks of infection and persist for life 1
• HSV-2 is primarily associated with genital herpes, with higher rates of symptomatic recurrences and subclinical viral shedding compared to HSV-1 genital infections 1

Test Limitations and Confirmation

• Commercial HSV-2 serologic tests using enzyme immunoassay (EIA) or chemiluminescent immunoassay (CLIA) have significant specificity limitations, especially at lower index values 1
• Index values of 1.1-2.9 have only 39.8% specificity, while values ≥3.0 have improved specificity of 78.6% 1
• False positives are more common in individuals with HSV-1 infection, especially with low index values 1
• For low positive results (index value <3.0), confirmation with a second test using a different glycoprotein G antigen is recommended to improve diagnostic accuracy 1
• Using the Biokit HSV-2 rapid assay as a confirmatory test improves the specificity of HerpeSelect from 93.2% to 98.7% compared to Western blot 1
• Western blot/immunoblot is considered the gold standard for HSV serologic testing but has limited availability 1

Clinical Significance and Implications

• HSV-2 is a chronic infection that impacts long-term sexual health, making accurate diagnosis important 1
• Individuals with positive HSV-2 IgG may experience recurrent genital herpes outbreaks or remain asymptomatic while still potentially transmitting the virus 1
• False-negative results can occur in 12-30% of patients with recurrent HSV-2 DNA positive genital lesions, so clinical correlation is important 2
• A negative result within 12 weeks of potential exposure may represent the "window period" and should be repeated after 12 weeks if recent acquisition is suspected 1

Management Considerations

• Type determination (HSV-1 vs HSV-2) is important for counseling and prognosis, as HSV-2 has more frequent recurrences and subclinical shedding than HSV-1 in genital infections 1
• Treatment options include episodic therapy for outbreaks or suppressive therapy to reduce recurrences and transmission risk 1
• Preferred treatment regimens should prioritize dosing strategies that are most feasible for patient adherence 1
• The same medication dosages are recommended for both HSV-1 and HSV-2 genital infections, despite less comprehensive studies for HSV-1 1

Appropriate Use of HSV-2 Serology

• Type-specific serology should be used for detecting asymptomatic infections, testing pregnant women at risk of acquiring HSV close to delivery, men who have sex with men, and people who are HIV positive 1
• Widespread screening for HSV antibodies is discouraged 1
• Serological tests alone cannot determine the etiology of a presenting genital lesion with certainty 1
• Symptom history alone is not a reliable predictor of HSV-2 seropositivity, as many infected individuals remain asymptomatic 3