Genital herpes is a sexually transmitted infection that can cause genital pain and sores. Though the virus is rarely life-threatening for most people, it can be dangerous in newborns. A virus flare-up during pregnancy increases the risk for premature labor and transmission to the baby during pregnancy or during delivery.

It is estimated that in 2018, about 18.6 million people in the United States between ages 18 and 49 had genital herpes. Some people with the virus never experience the tell-tale outbreak of blisters and sores, but they are still contagious. This is why getting tested for the genital herpes virus is important.

“There is a DNA test that takes just four hours, whereas just a few years ago, a diagnostic test could take a week or two,” says Angelique Levi, MD, Yale Medicine’s director of pathology outreach.

There is no cure for genital herpes, but outbreaks can be managed with medication.

Genital herpes is an infection caused by the herpes simplex virus (HSV).
There are two types of herpes simplex virus:

• HSV-1, which causes oral herpes and can lead to symptoms, including cold sores around the mouth. HSV-1 can also cause genital herpes.
• HSV-2, which is the most common cause of genital herpes.

The virus is transmitted via direct skin contact with someone who has an HSV infection, in particular through contact with herpes sores and blisters. It is possible, however, for the virus to be transmitted when there are no skin lesions present.

People often get infected by HSV through vaginal, anal, or oral sex with someone who has an infection. For instance, HSV-1 may spread (and cause genital HSV-1 infection) through oral sex. HSV may also spread through genital contact. Condoms can reduce, but not entirely prevent, the transmission of HSV.

Genital herpes can also be spread to babies during childbirth.

Herpes can be transmitted to an unborn baby before birth or, more commonly, during delivery. The virus may cause premature labor and babies can contract the virus in the womb or when passing through the birth canal. While herpes often does not cause serious symptoms in healthy adults, it can cause significant symptoms in newborns. Pregnant individuals with a genital herpes outbreak may be advised to take antiviral medications beginning at 36 weeks to reduce the chances of having outbreaks in late pregnancy and the need for a C-section. If a pregnant person has an active outbreak close to the time of labor and delivery, a C-section will be performed to prevent passing the virus to the newborn.

• Clinical assessment: Your provider can conduct a visual exam to determine if sores and blisters are present. Some genital herpes outbreaks are accompanied by a fever, so your vital signs will be checked, too. In many cases, a clinical exam may be sufficient for diagnosis. However, for first time occurrences, or in cases where symptoms are mild, it may be best to perform a more definitive diagnostic test. If genital herpes is suspected, additional tests may be needed to confirm diagnosis.
• Viral culture: In this test, a health care provider uses collects a fluid sample from an open sore or blister. Often, a cotton swab is used for this step of the procedure. In a laboratory, the sample is added to a dish containing cells that the HSV virus can infect. The cells are maintained in specific conditions so they will grow and replicate. If HSV is present in the fluid sample, it will infect the cells.
• Polymerase chain reaction (PCR) testing: A health care provider collects a fluid sample from an open sore or blister. Using a technique called PCR, the sample is then checked for the presence of HSV DNA.
• Blood tests: Blood tests are available that can detect the presence of antibodies and determine whether an infection is caused by HSV-1 or HSV-2. Bloodwork can be used to diagnose herpes even if a person does not have any open sores or blisters.

Though genital herpes is not curable, it can be managed. Your physician may prescribe an antiviral medication, such as acyclovir, valacyclovir, or famciclovir, to use during an outbreak. Over-the-counter pain medication, cool compresses, lidocaine gels and ointments, and sitz baths (soaking in shallow water that covers the hips and buttocks) can also be used to soothe symptoms. Your physician can provide advice on how to prevent transmission of the virus to sexual partners along with suggestions about how to discuss the topic of genital herpes openly.

As an academic medical center, Yale Medicine provides a wide range of treatment options for patients. Our doctors are expert at diagnosing and treating difficult cases and helping manage the condition for people at risk, such as pregnant women. Our doctors have access to the most advanced technology for diagnosing herpes and other medical conditions. Also, our researchers continue to look for new information about the herpes virus.