From the Guidelines
HSV blood testing is generally not recommended for routine screening in asymptomatic individuals. Blood tests for herpes simplex virus (HSV) should only be ordered in specific clinical scenarios, such as when a patient has recurrent genital symptoms without a clear diagnosis, when a pregnant woman has a partner with genital herpes, or when someone has a partner with known HSV infection 1. The most commonly used blood test is the type-specific glycoprotein G-based assay that can distinguish between HSV-1 and HSV-2 antibodies. These tests detect antibodies that develop 2-12 weeks after infection, indicating past or current infection, but cannot determine the site of infection or when it was acquired.
Key Considerations
- False positives can occur, particularly in low-risk populations, and a positive result may cause unnecessary psychological distress given the stigma associated with herpes 2.
- For active lesions, direct testing methods like PCR or viral culture from the lesion are preferred as they provide more accurate diagnosis and information about the infection site.
- If HSV testing is deemed necessary, patients should receive thorough counseling about the implications of both positive and negative results before testing is performed.
Clinical Scenarios for Testing
- Persons who have genital symptoms that could be consistent with genital herpes infection should undergo HSV-2 serologic testing to establish the diagnosis of HSV-2 infection 1.
- People who have been told that they have genital herpes without a virologic diagnosis have a high pretest probability of HSV-2 infection and should undergo HSV-2 serologic testing.
- Persons who are at increased risk of HSV-2 infection based on epidemiologic risk could be considered for HSV-2 serologic screening, with the goal of identifying undiagnosed symptomatic infection.
From the FDA Drug Label
Type‑specific serologic testing of asymptomatic partners of persons with genital herpes can determine whether risk for HSV‑2 acquisition exists The answer to whether it is recommended to order HSV testing (blood) is yes, but only for asymptomatic partners of persons with genital herpes to determine the risk of HSV-2 acquisition. 3
From the Research
HSV Testing Recommendations
- The US Preventive Services Task Force (USPSTF) recommends against routine serologic screening for genital HSV infection in asymptomatic adolescents and adults, including pregnant persons, as the harms outweigh the benefits 4.
- A systematic review found that serologic screening for genital herpes is associated with a high rate of false-positive test results and potential psychosocial harms, and evidence from RCTs does not establish whether preventive antiviral medication for asymptomatic HSV-2 infection has benefit 5.
Considerations for Testing
- The USPSTF concludes that the current evidence is insufficient to assess the balance of benefits and harms of screening for genital HSV infection in asymptomatic adolescents and adults, including pregnant persons 4.
- A study found that the use of serologic screening tests for HSV-2 in a population with a prevalence of 16% would result in a high number of false-positive results, with a positive predictive value of 50% 5.
Alternative Approaches
- The USPSTF recommends that clinicians consider the diagnosis of genital herpes in patients with symptoms of the infection, and use clinical judgment to determine the need for testing 4.
- A review of oral antiviral treatments for genital herpes found that acyclovir, famciclovir, and valacyclovir are effective in reducing the frequency and severity of outbreaks, but the choice of treatment should be individualized based on patient preferences and medical history 6, 7, 8.