Herpes simplex virus (HSV) is a common infection affecting billions globally, making a partner’s diagnosis a frequent source of anxiety about one’s own status. The virus exists in two primary types: HSV-1 and HSV-2, both of which are lifelong infections that remain in the body. HSV-1 is historically associated with oral herpes or cold sores, while HSV-2 is most commonly linked to genital herpes, although both types can infect either area of the body. Globally, approximately 67% of people under the age of 50 carry HSV-1, and 13% of people aged 15–49 have HSV-2.
Factors Determining Your Risk
An exposure to the virus does not automatically guarantee infection, and several factors influence the likelihood of transmission from an infected partner. The type of HSV plays a role; genital HSV-2 reactivates and sheds more frequently than genital HSV-1, making HSV-2 generally more likely to be transmitted. The frequency and duration of sexual contact also increase the cumulative risk over time.
Gender is another variable, as studies show that in heterosexual couples, women are biologically more susceptible to acquiring HSV-2 from an infected male partner than men are from an infected female partner. A partner’s viral management status also significantly alters the risk, particularly if they are aware of their infection and are taking daily suppressive antiviral medication. These factors combine to create a unique risk profile for every couple, which is why a discussion with a healthcare provider is important for personalized risk assessment.
How Herpes Spreads
The physical mechanism of herpes transmission is direct skin-to-skin contact with the virus, which can be present on the skin, mucosal surfaces, or in genital secretions. Transmission most readily occurs when an infected person has an active outbreak, which involves visible blisters or sores that contain high concentrations of the virus. This period also includes the prodrome phase, characterized by localized tingling, itching, or pain that precedes the appearance of any lesions.
The majority of transmissions occur when the infected partner has no visible symptoms, a phenomenon known as asymptomatic viral shedding. During this process, the virus reactivates in the nerve ganglia and travels down the nerve axon to the skin’s surface, where it is shed into the environment. This shedding happens periodically and is a major reason why many people acquire the virus from partners who are unaware they are contagious.
Getting Tested
The only definitive way to determine your status is through specific laboratory testing. If you have any active, visible lesions or sores, a healthcare provider can perform a swab test, often using a Polymerase Chain Reaction (PCR) technique, to detect the virus’s genetic material. PCR is highly sensitive and can accurately identify whether the infection is HSV-1 or HSV-2.
For individuals without symptoms, blood testing is the appropriate method, as it looks for antibodies that the immune system produces in response to the virus. The most reliable blood test detects immunoglobulin G (IgG) antibodies, which are type-specific and remain detectable for life after infection. IgG testing is preferred over immunoglobulin M (IgM) tests, as IgM can be misleading and does not accurately distinguish between the two virus types.
Timing is an important consideration for blood tests, as the body requires a “window period” for IgG antibodies to reach detectable levels. Testing too early can result in a false-negative result, so it is recommended to wait at least 12 weeks after the last possible exposure for the most accurate IgG blood test results. Discussing your specific exposure timeline with a healthcare provider is necessary for determining the correct testing schedule and interpreting the results accurately.
Reducing the Risk of Transmission
Several specific interventions can significantly lower the chance of transmission in couples where one partner is positive and the other is negative. The consistent and correct use of barrier methods, such as male or female condoms, can reduce the risk of HSV transmission by up to 50%. Condoms provide protection by covering the areas of potential viral contact, though transmission can still occur through contact with areas of skin not covered by the barrier.
Avoiding all sexual activity from the moment a partner experiences prodrome symptoms until any lesions are completely healed and new skin is present is a behavioral precaution. For the infected partner, taking a daily suppressive dose of an antiviral medication, such as valacyclovir, can dramatically reduce the frequency of both symptomatic outbreaks and asymptomatic viral shedding. This suppressive therapy can reduce the transmission rate to a negative partner. Open communication about symptoms and risk management is foundational to successfully implementing these preventative strategies.