Diagnostic Testing for Herpes Simplex Virus Type 2 (HSV-2)

Testing Strategy Based on Clinical Presentation

For active genital lesions, the American College of Physicians recommends using nucleic acid amplification testing (NAAT/PCR) from the lesion as the first-line diagnostic test, with sensitivity and specificity exceeding 90% for most FDA-approved assays 1
The Centers for Disease Control and Prevention (CDC) suggests that NAAT/PCR is the preferred diagnostic test for detecting HSV-2 from genital ulcers or lesions, offering 11-71% superior sensitivity compared to viral culture 1
The optimal sampling technique for NAAT/PCR includes collecting fluid from intact vesicles or swabbing the base of ulcers, with specific methods for male and female patients 3
If NAAT is unavailable, the CDC recommends viral culture as a second-choice diagnostic method, though it has significantly lower sensitivity 1

The sensitivity of HSV-2 serologic testing is high at 92%, but false-negatives can occur during the early window period, according to the Clinical Infectious Diseases journal 1
The US Preventive Services Task Force recommends that a negative result within 12 weeks of potential exposure may represent the "window period" before antibodies develop 2
For low positive results (index value <3.0), the CDC recommends confirming with a second test using a different glycoprotein G antigen to avoid false-positive results 2

The American College of Obstetricians and Gynecologists recommends type-specific HSV-2 serology for pregnant women at risk of acquiring HSV infection close to delivery, as well as for men who have sex with men and people who are HIV positive 2
The CDC does not recommend widespread screening for HSV-2 antibodies in the general asymptomatic population, due to the potential for false-positive results and the limited availability of Western blot/immunoblot testing 2

A positive HSV-2 IgG antibody test indicates past exposure and ongoing latent infection with HSV-2, with antibodies persisting indefinitely, according to the Clinical Infectious Diseases journal 4
Patients with positive HSV-2 serology should be counseled about the natural history of disease, potential for recurrent episodes, asymptomatic viral shedding, and sexual transmission risk, as recommended by the American College of Physicians 2