The absence of Herpes Simplex Virus (HSV) from routine sexually transmitted infection (STI) screening confuses many people seeking testing. Standard screenings typically include tests for Human Immunodeficiency Virus (HIV), syphilis, chlamydia, and gonorrhea, conditions that benefit significantly from early detection. Unlike these infections, HSV is generally excluded from universal screening for asymptomatic individuals. This exclusion is rooted in limitations related to available testing technology and broader public health considerations.
The Challenge of Antibody Screening
Routine testing for HSV relies on a blood test that detects Immunoglobulin G (IgG) antibodies, which indicate past exposure rather than an active infection. This serological method presents technical limitations that make it unsuitable for broad population screening. The body requires time to produce detectable levels of IgG antibodies, creating a “window period” that can last up to four months after initial exposure.
A negative antibody result during this window period does not rule out recent infection, leading to false assurance. Commercially available antibody tests also risk producing false-positive results, particularly in populations with low virus prevalence. For some tests used in the U.S. primary care population, nearly one in two positive results is estimated to be false, creating diagnostic uncertainty.
A positive HSV antibody test confirms only that an individual has been exposed to the virus, not when the infection occurred or if the person is infectious. The test often cannot distinguish between oral and genital infection sites, especially for HSV-1, which can be acquired non-sexually. Testing for active infection requires a viral culture or Polymerase Chain Reaction (PCR) test taken directly from a lesion or sore, serving as a diagnostic tool, not a screening one.
Lack of Broad Public Health Benefit
The decision to forgo routine screening is supported by the limited public health benefit of diagnosing asymptomatic carriers. Herpes is highly prevalent; estimates suggest more than one in six people aged 14 to 49 in the United States have HSV-2, though most are unaware. Since there is no cure, diagnosing an asymptomatic person does not significantly alter the course of their disease or reliably reduce population-level transmission rates.
This contrasts sharply with STIs like chlamydia and gonorrhea, which are curable with antibiotics and can cause severe complications such as infertility if left untreated. Early diagnosis of HIV or syphilis allows for highly effective treatments that prevent severe morbidity and significantly reduce transmission likelihood. For HSV, routine diagnosis of a symptomless infection has not been shown to provide a comparable public health advantage.
The majority of people who test positive for HSV antibodies will never experience symptoms or will have only mild outbreaks. Identifying these individuals through mass screening does not translate into a widespread intervention that prevents severe disease or significantly curbs the virus’s spread. The rationale for initiating antiviral treatment in asymptomatic individuals based solely on a blood test is unclear and not universally recommended.
Official Guidelines and Psychological Costs
Major health organizations advise against universal screening for asymptomatic individuals because the potential harms outweigh the minimal benefits. Both the U.S. Preventive Services Task Force (USPSTF) and the Centers for Disease Control and Prevention (CDC) recommend against routine serologic screening for asymptomatic adults and adolescents, including pregnant individuals. This is classified as a Grade D recommendation, meaning the service is not recommended.
A primary concern is the psychological burden associated with receiving a positive diagnosis for a chronic, incurable condition that may never cause symptoms. False-positive results, which are common with antibody tests, can lead to anxiety, emotional distress, and disrupted personal relationships. This contributes to “over-diagnosis,” where people are labeled with a chronic medical condition without tangible clinical benefit.
The official guidelines recognize that subjecting the general population to a test with a high false-positive rate and limited clinical utility can create psychosocial harm. The stigma and stress of being labeled with a chronic STI outweigh the small potential for preventing transmission or altering the mild course of the disease for most carriers. This policy reflects a balancing of public health goals against individual well-being and diagnostic accuracy.
Situations Requiring Targeted Testing
While routine screening is not recommended, testing is available and necessary in specific clinical situations. Individuals presenting with genital lesions, sores, or symptoms consistent with a herpes outbreak should be tested, typically using a viral culture or PCR swab of the lesion for an accurate diagnosis. This approach confirms whether the symptoms are caused by HSV-1 or HSV-2.
Serologic antibody testing is appropriate for targeted populations, such as individuals whose partner has recently been diagnosed with genital herpes. It is also recommended for those undergoing a comprehensive STI evaluation who have multiple partners or other risk factors. Testing is sometimes considered in pregnant individuals who have a partner with herpes or present with atypical symptoms, due to the serious risk of neonatal herpes.
People with HIV or other immunosuppressive disorders may be candidates for targeted HSV testing, as they are at higher risk for severe or prolonged outbreaks. In these circumstances, the information gained from testing has clear clinical utility that justifies the diagnostic effort. The focus remains on using the test as a diagnostic tool for symptomatic or high-risk patients, rather than a broad screening tool.