HSV-1 Risk Estimator
Before you begin:
Are you currently experiencing symptoms or have you recently been in contact with someone who tested positive?
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.
Herpes simplex virus type 1 (HSV-1) is one of the most common infections worldwide. The WHO estimates that 3.7 billion people under age 50 carry HSV-1. Most infections are oral, acquired in childhood through non-sexual contact such as kissing. HSV-1 can also cause genital herpes through oral-genital contact. Many carriers are asymptomatic and unaware of their status.
This calculator uses a gradient-boosted classifier trained on individual-level serology results from the CDC's National Health and Nutrition Examination Survey (NHANES), spanning 2005–2016 with approximately 18,000 participants. It estimates the probability that a person with your demographic profile has HSV-1 antibodies.
Your percentage represents the estimated probability that a person with your profile has HSV-1 antibodies, based on patterns in the NHANES population. The red line on the gauge shows the US population average (~48%). Being above or below this line provides context, not a diagnosis.
This calculator estimates the statistical probability that you have been infected with herpes simplex virus type 1 (HSV-1) based on your demographic information. It uses seroprevalence data from NHANES to generate an estimate. It does not test you for the virus or provide a medical diagnosis.
No. This calculator provides a statistical estimate only. It cannot diagnose HSV-1 or any other medical condition. A diagnosis of HSV-1 requires laboratory testing, such as a type-specific IgG blood test or a PCR swab of an active lesion. If you think you may have herpes, please see a healthcare provider for proper testing. You can also order an HSV-1 blood test online through STDCheck.com.
The most common tests include type-specific IgG antibody blood tests (such as HerpeSelect or BioPlex), which detect antibodies indicating past infection. If you have an active sore, a PCR swab test or viral culture can confirm the presence of the virus directly. IgM tests are generally not recommended because they are unreliable for distinguishing between HSV-1 and HSV-2. STDCheck.com offers a type-specific HSV-1 IgG test you can order online with results in 1-2 days.
HSV-1 is most commonly associated with oral herpes (cold sores). However, HSV-1 can also cause genital herpes, typically through oral-genital contact. In recent years, HSV-1 has become an increasingly common cause of genital herpes, particularly among young adults. Genital HSV-1 tends to recur less frequently than genital HSV-2.
It typically takes 2 to 12 weeks for IgG antibodies to develop, with most people seroconverting within 4 to 6 weeks. Testing too soon may produce a false negative. If you had a recent exposure and test negative, your provider may recommend retesting after 12 weeks.
Yes. HSV-1 can be transmitted through asymptomatic viral shedding, meaning the virus is present on the skin or mucous membranes without visible symptoms. This is one of the primary ways HSV-1 spreads, since many carriers are unaware they are shedding the virus.
Currently, the CDC and USPSTF do not recommend routine screening for HSV-1 in asymptomatic individuals. Testing is generally recommended only for people with symptoms, those with a partner known to have herpes, or in certain clinical situations where knowing HSV status would affect management.
Yes, although neonatal herpes is rare. The greatest risk occurs when a mother acquires a new HSV infection near delivery. If a pregnant woman has a history of genital herpes (HSV-1 or HSV-2), antiviral suppressive therapy is typically recommended starting at 36 weeks. If active lesions are present at labor, cesarean delivery is usually recommended.
See a healthcare provider if you have symptoms you think might be herpes (recurring sores on the mouth or genitals), if you have been exposed to a partner with known herpes, if you are pregnant, or if you have a test result you need help interpreting. This calculator is an educational tool, not a substitute for medical advice.
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