Guidelines for HSV‑1 and HSV‑2 IgG Serology Testing

When Serologic Testing Is Indicated

Type‑specific HSV IgG testing should be reserved for selected clinical situations—such as evaluation of past infection in asymptomatic persons, assessment of pregnant individuals at risk of acquiring HSV near delivery, screening of men who have sex with men, evaluation of HIV‑positive patients, and investigation of suspected genital herpes when lesions are absent or healed—rather than for population‑wide screening. 1
Routine, widespread screening for HSV antibodies is discouraged because of suboptimal test performance. 1

Commercial HSV‑1 IgG assays have limited sensitivity, missing approximately 15 %–30 % of true infections; overall sensitivity is often below 85 %. 2
Specific assay data (illustrative):
- Bio‑Rad and Roche platforms: sensitivity < 85 % with specificity > 97 %.
- DiaSorin platform: sensitivity ≈ 92 % but specificity ≈ 89 %.
- HerpeSelect HSV‑1 assay: sensitivity ≈ 70 % in validation studies.
A negative HSV‑1 IgG result cannot reliably exclude prior HSV‑1 infection. 2

Roche and Bio‑Rad HSV‑2 assays demonstrate high accuracy, with sensitivity > 97 % and specificity > 98 %. 2
DiaSorin HSV‑2 testing shows a substantial false‑positive rate; at a population prevalence of 12 %, the positive predictive value is only about 69 % (≈ 1 in 3 positive results may be false). 2
HerpeSelect HSV‑2 ELISA yields lower specificity for index values between 1.1 and 3.5, necessitating confirmatory testing. 2
Low‑positive index values (< 3.0) are especially prone to false‑positivity: approximately 60.9 % of DiaSorin HSV‑1 and 20.8 % of DiaSorin HSV‑2 results with such indices are false positives. 2

Serologic testing is not recommended for patients with active genital ulcers. Direct viral detection should be employed:

Use type‑specific IgG assays that target glycoprotein G‑1 (HSV‑1) and G‑2 (HSV‑2). 2
Verify which commercial platform the laboratory employs; Roche and Bio‑Rad assays provide more reliable HSV‑2 results than DiaSorin. 2
Low‑positive serologic results should be confirmed with a reference method such as Western blot or an inhibition assay. 2

HSV‑1 antibodies may interfere with HSV‑2 testing, leading to indeterminate inhibition results in individuals with high HSV‑1 IgG levels. 2
IgG antibodies may not become detectable until several weeks to months after initial infection, so early testing can yield false‑negative results. 2

All statements are supported by the cited literature.