Genital Herpes Chance

HSV-2 Risk Estimator

Important: This tool provides statistical estimates only and does not diagnose HSV-2. A risk estimate is not a test result. Only laboratory testing (type-specific IgG blood test or PCR swab) can confirm or rule out infection. If you have symptoms or believe you have been exposed, consult a licensed healthcare provider. See our Medical Disclaimer.
Privacy Note: Your data is not stored or shared. All calculations are performed on the server and no personally identifiable information is retained after your session ends. No account or sign-up required.

Before you begin:

Are you currently experiencing symptoms or have you recently been in contact with someone who tested positive?

This calculator may not be right for you

This tool estimates risk based on demographic and lifestyle factors for people without known symptoms or exposure. It is not designed to assess the likelihood of infection after a specific exposure or to evaluate active symptoms.

If you have symptoms or known exposure, lab testing is the appropriate next step. A healthcare provider can order the right tests and interpret the results for your situation.

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About This HSV-2 Calculator

Herpes simplex virus type 2 (HSV-2) is the primary cause of genital herpes and affects hundreds of millions of people globally. Transmission occurs through sexual contact, including during periods of asymptomatic viral shedding when no sores are visible. US seroprevalence is approximately 12%.

This calculator uses a gradient-boosted classifier trained on individual-level serology results from the CDC's NHANES, spanning 2005–2016 with approximately 18,000 participants. Key risk factors include number of lifetime sexual partners, biological sex (higher in women), race/ethnicity, and substance use history.

What results mean

Your percentage represents the estimated probability that a person with your profile has HSV-2 antibodies. The red line on the gauge shows the US population average (~12%). Being above or below this line provides context, not a diagnosis.

Limitations

  • This is a statistical estimate, not a test result. No blood was drawn and no laboratory analysis was performed.
  • The model detects antibody status (past or present infection), not active infectiousness or outbreak frequency.
  • Correlation is not causation. Some variables improve prediction without directly causing infection.
  • NHANES surveys US civilian non-institutionalized residents. Patterns may differ elsewhere.
  • Results should not be used to make treatment or disclosure decisions without consulting a clinician.
Medically reviewed by Mark Sanborn, PhD — Biomedical researcher specializing in bioinformatics, genomics, and statistical modeling. Last reviewed March 2026. See methodology · Medical disclaimer

Frequently Asked Questions

What does this HSV-2 calculator estimate?

This calculator estimates the statistical probability that you have been infected with herpes simplex virus type 2 (HSV-2) based on your demographic and lifestyle information. It uses seroprevalence data from NHANES. It is not a medical test and cannot provide a diagnosis.

Can this tool confirm genital herpes?

No. Confirming genital herpes requires a laboratory test such as a type-specific HSV-2 IgG blood test or a PCR swab of an active lesion. If you suspect you have genital herpes, see a healthcare provider. You can also order an HSV-1 & HSV-2 blood test online through STDCheck.com.

Can HSV-2 IgG tests be falsely positive?

Yes. The HerpeSelect HSV-2 IgG ELISA can produce false positives, particularly at low index values (1.1–3.5). The CDC recommends confirming low-positive results with the BioPlex assay or the University of Washington Western blot. If you haven't been tested yet, STDCheck.com offers a Herpes I & II panel with confidential results in 1-2 days.

Can HSV-2 spread without visible sores?

Yes. HSV-2 can be transmitted through asymptomatic viral shedding. Studies show shedding occurs on 10–20% of days in the first year after infection. This is a primary transmission route since many carriers are unaware they are shedding.

Does daily antiviral therapy reduce transmission?

Yes. Daily suppressive therapy with valacyclovir reduces transmission risk by about 48%. Combined with consistent condom use, the reduction is greater. Suppressive therapy also reduces outbreak frequency and asymptomatic shedding.

How well do condoms reduce HSV-2 transmission?

Consistent condom use reduces HSV-2 transmission risk by approximately 30–50%. Condoms do not provide complete protection because HSV-2 can be shed from areas not covered by a condom.

Should people without symptoms be screened for HSV-2?

The CDC and USPSTF do not recommend routine screening for asymptomatic individuals. Testing may be appropriate for people with a partner known to have genital herpes, those with HIV, or those who request testing after counseling about limitations.

Can HSV-2 affect pregnancy?

Yes. Neonatal herpes can be serious. Antiviral suppressive therapy is typically recommended starting at 36 weeks. If active genital lesions are present at labor, cesarean delivery is recommended. The highest risk is when a mother acquires HSV-2 for the first time near delivery.

When should I see a doctor instead of using this calculator?

See a healthcare provider if you have symptoms (blisters, sores, or ulcers in the genital area), known exposure to a partner with HSV-2, are pregnant, or need help interpreting test results. This calculator is for education only.

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Data Sources

For full technical details, see our Methodology page. Questions about editorial standards are addressed in our Editorial Policy.