Facts About the Genital Herpes Virus You May Not Know (2024)

Herpes simplex virus type 2 (HSV-2) is the virus most commonly linked to genital herpes, a sexually transmitted infection (STI) that causes painful blisters and ulcers on the penis, vagin*, or rectum. The virus is passed during intimate sexual contact prior to and following the outbreak of ulcers.

Herpes simplex type 1 (HSV-1) is a related virus more commonly linked to oral herpes (a.k.a. cold sores). Even so, HSV-1 can sometimes be passed to the genitals during oral sex.

Although HSV-2 accounts for most genital herpes outbreaks, it is impossible to tell which virus caused the infection without lab tests.

This article looks at the causes and symptoms of genital herpes and explains how this common viral disease is diagnosed and treated. It also offers tips on when to seek treatment to potentially reduce the duration and severity of an outbreak.

HSV-2 Causes

Genital herpes, also known as herpes genitalis, is one of the most common STIs in the world. It is caused by HSV-2 and, increasingly, by HSV-1.

According to the Centers for Disease Control and Prevention (CDC), around 12% of people in the United States between the ages of 14 and 49 have HSV-2. In 2021, an estimated 572,000 people nationwide were newly infected.

Sex is the predominant mode of transmission. Generally, you can only get HSV-2 when there is genital-to-genital contact with someone who has a genital HSV-2 infection. However, receiving oral sex from someone with an oral HSV-1 infection can also lead to genital herpes.

Once you've been infected with HSV-2, it does not go away. Instead, the virus remains in the body in a latent (dormant) state, embedded in nerve cells near the spine. Triggers like stress, illness, or hormonal changes can cause the virus to reactivate and travel along the nerve route to the site of the original infection, causing a repeated outbreak (recurrence).

Asymptomatic Infection

Not everyone who gets HSV-2 will develop genital herpes. Some people will remain asymptomatic (symptom-free) but still be able to pass the virus to others without knowing it.

While exposure to herpes sores can easily transmit the virus, HSV-2 infections most often occur when you have sex with someone who is either asymptomatic or has mild symptoms that are not readily recognized as herpes. In cases like these, there will be periods during which the virus can be "shed" through the skin of the genitals or rectum.

Some studies suggest that asymptomatic HSV-2 shedding can occur as much as 10% of days.

HSV-2 Symptoms

Not everyone with HSV-2 has symptoms or is even aware that they've been infected. Research suggests that around 87% of people with HSV-2 under the age of 50 have never been diagnosed. Most are either asymptomatic or have very mild symptoms that are easily mistaken for other skin conditions.

When symptoms do occur, they usually involve the spontaneous appearance of tiny blisters around the genitals or rectum. Soon after, the blisters will rupture, leaving painful ulcers that ooze, crust over, and eventually heal within two to four weeks.

First and Subsequent Episodes

The first genital herpes outbreak will generally be worse than the ones that follow. During a first outbreak, the appearance of lesions will often be accompanied by:

• Fever
• Headache
• Body aches
• Swollen lymph nodes
• Pain or burning with urination
• Unusual vagin*l discharge

Subsequent attacks tend to be shorter and less severe. They are often preceded by genital pain or shooting pain in the legs, hip, or buttocks several hours or days before the attack.

Over time, the number of outbreaks tends to decrease and become less severe.

Complications

For most people with genital herpes, symptoms can be aggravating but not life-threatening.

However, for people who are severely immunocompromised, such as those with advanced human immunodeficiency virus (HIV), HSV-2 can cause rare but serious complications like aseptic meningitis (inflammation of the lining of the brain).

On the flip side, having HSV-2 increases the risk of getting HIV by around 300%. This is not only because HIV has easier access into the body through open sores but also because HSV-2 increases the number of immune cells, called CD4 T cells, that HIV targets for infection.

Genital herpes can also be passed to the fetus during pregnancy, leading to a potentially life-threatening condition known as neonatal herpes. If transmission occurs, the virus can reactivate soon after birth and spread to the baby's lungs, liver, brain, or circulatory system, causing severe illness and even death.

What Does Genital Herpes Look Like?

Genital herpes symptoms can differ from one person to the next, causing a massive outbreak in some people and an uncomfortable rash or redness that can easily be mistaken for other conditions.

When an outbreak is about to occur, people will often experience prodromal (precursor) symptoms such as tingling, itching, or burning around the area where the sores are about to appear.

Soon after, a cluster of itchy or painful blisters filled with fluid will appear on the vagin*, vulva, cervix, penis, scrotum, buttocks, anus, or upper thighs. The blisters can vary both in size and density. As the blisters begin to rupture, they turn into open sores that can bleed or ooze a whitish fluid.

Over a period of several days, the sores will begin to crust over and heal. Most outbreaks clear within two to four weeks, usually without leaving any scars.

When to See a Healthcare Provider

The early recognition of genital herpes, ideally during the prodromal stage, allows you to access treatments that can shorten the duration and severity of an outbreak.

Clearly, this can be difficult during your first outbreak, given that you probably won't be expecting it. But, over time, you will be better able to recognize the tell-tale signs and know when it's time to act.

Getting treated also reduces the risk of infecting others by slowing the rate of viral shedding.

HSV-2 Diagnosis

Genital herpes is often diagnosed with a physical exam and a swab of cells from a herpes sore. The swab can be used for one or several different tests, including:

• Light microscopy: Used to visualize the cells under a microscope
• Viral culture: Used to culture (grow) the virus in the lab
• Nucleic acid amplification test (NAAT): Used to detect HSV based on its genetic material and to help differentiate between HSV-1 and HSV-2

There also are blood tests that can diagnose HSV based on proteins called immunoglobulins (antibodies) produced by the immune system in response to the virus.

The two categories of antibody tests used to detect HSV are:

• Immunoglobulin M (IgM) tests: Used to detect an antibody produced soon after infection, which may help diagnose early infection
• Immunoglobulin (IgG) tests: Used to detect a longer-lasting antibody, which can help differentiate between a recent infection and a recurrence

Certain IgG blood tests can also tell you whether you have HSV-1 or HSV-2.

Treatment

There is no cure for HSV-2. However, antiviral drugs can reduce the duration and severity of an outbreak. They can also reduce the risk of outbreaks in people with recurrence and reduce the risk of passing the virus to others.

The treatment varies based on whether this is your first or subsequent outbreak.

First Outbreak

Everyone who gets a first herpes outbreak should be treated. While many experts recommend initiating treatment within 72 hours of the appearance of lesions, there are still benefits if treatment is started after 72 hours.

Among them, people who are not treated during their first outbreak are more likely to experience severe or prolonged recurrences in the future, even if their initial symptoms were mild.

The CDC recommends three antiviral therapies for a first episode of genital herpes, regardless of the viral type. They are all taken by mouth. Medication doses are measured in grams (g) or milligrams (mg).