Skip to Main Content

Herpes Simplex

  • A sexually transmitted disease that can cause genital pain and sores
  • Symptoms include itchy or painful blisters on vagina or penis
  • Treatment includes antiviral medication, and over-the-counter medication
  • Involves OB/GYN and urology

Herpes Simplex


Genital herpes is likely the most feared and least understood sexually transmitted infection (STI). There is no cure, so people infected with herpes have it forever. Though the virus is rarely life-threatening for most people with it, it’s extremely dangerous for pregnant women. A virus flare-up during pregnancy increases her risk of premature labor and an unborn baby can get a deadly infection in the womb.

What may be surprising is that about one in six people between ages 14 and 49 have the STI and don’t know it, according to the Centers for Disease Control and Prevention (CDC). 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 extremely important. “We at Yale now have 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.

What is herpes?

Herpes is a viral infection that comes in two types. Oral herpes is caused by a harmless virus called the herpes simplex virus 1 (HSV-1). It is easily passed from one person to another through skin contact, and, as a result, almost all people are exposed to it as children or young adults. If you’ve ever had an outbreak of cold sores or fever blisters around your mouth or elsewhere on your face, then the likely culprit is HSV-1. These cold sores may recur as the infection is lifelong, but outbreaks are usually self-limited.

A different virus called the herpes simplex virus 2 (HSV-2) causes genital herpes. This form of herpes can result in both internal and external sores, and blisters in the genital area, which can arise several days, weeks, or months after exposure. Some people may never experience visible symptoms. According to the CDC, having the genital herpes virus puts people at an increased risk of getting an HIV infection, if exposed.

How do you get herpes?

Oral herpes (HSV-1) can be spread through saliva, kissing, and skin-to-skin contact. HSV-1 can also cause genital herpes, if the genital areas are exposed to fever blisters or sores on the mouth or face, or through oral sex. Even though HSV-1 also never completely goes away, that strain of the virus causes fewer outbreaks over time in the genital areas than HSV-2.

Genital herpes (HSV-2) can be transmitted through skin-to-skin contact and/or sexual intercourse of all types (oral, vaginal and anal). Most people don’t realize that sores from genital herpes can appear on the face as well as the genital area. Because the virus can spread any time contact occurs with a blister or sore, a condom doesn’t always provide sufficient protection.

How does genital herpes affect pregnant women?

While genital herpes rarely causes serious health problems in healthy men and women, HSV-2 can be dangerous for pregnant women and the neonate, particularly during the last trimester of pregnancy. The virus may cause premature labor and babies can contract the virus in the womb or when passing through the birth canal.

How is genital herpes diagnosed?

  • 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, your doctor will take a cotton swab and swipe an infected area to collect a sample for laboratory testing.
  • Testing of an infected site: Before advances in testing technology, doctors and patients had to wait one week or more for HSV-1 and HSV-2 results to be interpreted via a test that required the bacteria to be grown, or cultured, in a lab. This older technique may be the only testing option at other institutions. At Yale Medicine, there is a DNA assay that is used to detect and identify both HSV-1 and HSV-2 simultaneously. “This type of molecular test used in the Yale Pathology Laboratory delivers rapid and reliable results within four hours,” Dr. Levi says. Additionally, this molecular test uses an amplification step, which helps to detect viral DNA even at very low levels during different stages of infection or clinical presentation. As a result, this test provides sensitive and specific testing for HSV-1, and HSV-2, and, most importantly, allows for same day treatment in cases that are positive.
  • Blood test: A person worried about possible exposure to genital herpes can have a blood test that will detect the presence of specific HSV-1 and HSV-2 viral antibodies, regardless of symptoms or active infection. The presence of particular antibodies can also indicate whether the infection was recently acquired.

What treatment is available for genital herpes?

Though genital herpes is not curable, it can be managed. Your physician may prescribe an antiviral medication, including acyclovir, valacyclovir, and famciclovir, to use during an outbreak. Over-the-counter pain medication 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.

What stands out about Yale Medicine’s approach to genital herpes?

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.