Herpes Facts and Statistics: What You Should Know

Genital herpes caused by herpes simplex virus type 2 (HSV-2) is one of the most common sexually transmitted infections (STIs) worldwide. According to data from the Centers for Disease Control and Prevention (CDC), over half a million new HSV-2 infections occurred in the United States in 2018.

But, the actual number of cases may far exceed this estimate. This is because more and more genital herpes infections are being caused by a related virus known as herpes simplex virus type 1 (HSV-1), the type associated with cold sores.

What makes the scale of the epidemic all the more concerning is that most people with genital herpes do not know that they have it.

This article takes an in-depth look at the causes and scale of the genital herpes epidemic in the United States, including the risk factors and the groups disproportionately affected by infections. Learn facts about herpes.

Genital Herpes Overview

Genital herpes is an STI caused predominantly by herpes simplex virus type 2 (HSV-2). The viral infection triggers an outbreak of tiny blisters on the genitals or rectum that break open into painful, oozing ulcers. The outbreaks tend to be self-limiting but can recur, sometimes frequently.

In recent decades, more and more genital herpes infections are being caused by HSV-1, the type associated with oral herpes (cold sores). The genital transmission of the virus is through oral sex. The symptoms are often distinguishable from those of HSV-2.

Herpes can be diagnosed with a physical exam and a swab of herpes sores. Blood tests are also available to confirm the diagnosis.

There is no cure for genital herpes, but there are antiviral drugs that can reduce the severity and duration of an outbreak⁠ (and sometimes even avert it). In people with chronic (persistent) herpes, daily low-dose antivirals may be prescribed to reduce the frequency of outbreaks.

How Herpes Is Transmitted

Herpes is most efficiently passed via direct genital contact with a herpes lesion, but it can also be passed through skin-to-skin contact with someone who has an active infection but no symptoms.

The latter manner of transmission, referred to as asymptomatic genital shedding, occurs when the virus reactivates and literally sheds viruses out of the part of the body where the initial infection occurred.

In people with asymptomatic HSV-2, shedding can occur in episodes throughout the year, silently passing the infection without the person even realizing it.

Herpes also can be passed to a child during childbirth or shortly after birth if the baby comes into contact with lesions present on the birthing parent. This is otherwise referred to as maternal transmission or perinatal transmission. Less commonly, the virus can be transmitted while the fetus is still in the uterus.

How Common Is Genital Herpes?

Of the eight most common STIs in the United States⁠—chlamydia, genital herpes, gonorrhea, hepatitis B, human immunodeficiency virus (HIV), human papillomavirus (HPV), syphilis, and trichomoniasis—genital herpes ranks fifth in terms of annual new infections but second overall in terms of the number of people currently living with the disease.

According to the CDC, there are roughly 18.6 million people living with HSV-2 in the United States. In their most recent survey, the CDC estimated that 572,000 new infections occurred in a single year.

It is unknown how many additional cases may be caused by HSV-1, but conservative estimates place it in the tens of thousands each year. The figure may be higher given that nearly half of all people between the ages of 14 and 49 in the United States are thought to have HSV-1.

Even so, studies have shown that the rate of both HSV-1 and HSV-2 have been steadily declining for the past two decades, due in part to safer sex behaviors.

Genital Herpes by Race/Ethnicity

As with most infectious diseases, genital herpes is more prevalent among some racial/ethnic groups than others. This is especially true of Black people in the United States who are nearly 4 times as likely to have HSV-2 as White people.

The causes for this disparity are many, including poverty and limited access to health care and diagnosis. Institutional racism and healthcare discrimination can often discourage people from seeking the care they need, as well. Moreover, living in a community where STI rates are already high increases the likelihood of infection.

Even more concerning is the fact that genital herpes increases the risk of HIV, in part because open sores provide HIV easier access into the body and the inflammatory response attracts the very immune cells (called CD4 T-cells) that HIV targets for infection.

As a result of these intersecting risk factors, a 2013 study in the journal PLoS suggested that genital herpes in Black people increases their vulnerability to HIV three times more than in White people.

Genital Herpes by Age and Gender

In the United States, most new HSV-2 infections occur in people under 50 who tend to be more sexually active. Because genital herpes does not go away, the prevalence (the proportion of people affected over a specific period of time) will increase with age.

Data from the National Center of Health Statistics demonstrates how the HSV-2 prevalence in the United States increases with age:

• Age 14 to 19: 0.8% prevalence
• Ages 20 to 29: 7.6% prevalence
• Age 30 to 39: 13.3% prevalence
• Ages 40 to 49: 21.2% prevalence

In short, the older you get, the more likely the odds of having herpes if you are sexually active and have risk factors for the disease.

Causes of Genital Herpes and Risk Factors

Genital herpes is an enormous public health concern because a person doesn't have to have symptoms to infect others. Because many people with HSV-2 are unaware of their infection, they can continue to spread the virus without even knowing.

An estimated 87.4% of people between the age of 14 and 49 who are infected have never been diagnosed with HSV-2 and may not even realize they have the virus.

Risk factors for genital herpes include:

• Condomless oral, vaginal, or anal sex
• Multiple sex partners
• Anonymous sex partners
• Having other STIs, including HIV (which can reduce your immune defenses to infection)

What Are the Mortality Rates for Genital Herpes?

For most people, genital herpes may be aggravating and disruptive, but the condition is not associated with an increased risk of death. The one exception is newborns, in whom a herpes infection can be catastrophic.

Neonatal HSV occurs when a person with genital herpes transmits the virus to their baby before, during, or soon after childbirth. It is an uncommon condition that affects one of every 3,200 births in the United States. Around 85% of all transmissions occur as the baby passes through the birth canal.

If the central nervous system is affected, it can lead to herpes simplex encephalitis (HSE), a condition that causes severe swelling of the brain and leads to death in 70% of cases. While HSV-1 is the more common cause of HSE in adults, HSV-2 is often the culprit in newborns.

Screening and Early Detection

Unlike some STIs, routine blood testing (called serologic testing) is not recommended for people who don't have symptoms of herpes. However, if there is concern about exposure or new symptoms, this testing may be recommended. People should talk with a healthcare provider to determine whether blood testing is necessary.

Although blood testing is not routinely done, screening for STIs should include a thorough exam to check for herpes lesions on the genitals (including a speculum exam for females to check for lesions on the cervix).

The CDC recommends blood testing if you have symptoms of genital herpes. Testing should also be pursued if you are pregnant and are having sex with someone with herpes.

Testing may also be useful if:

• You are not pregnant but are having sex with someone with herpes.
• You have had a sex partner with herpes.
• You want a complete STI exam, especially if you have multiple sex partners.
  

Summary

Genital herpes is the fifth most common sexually transmitted infection in the United States in terms of new infections and the second most common with respect to the number of people living with the disease.

Currently, over 18 million people in the United States have herpes simplex virus type 2 (HSV-2), the type most commonly associated with genital herpes. In 2018, over 570,000 were newly infected. The majority of people with genital herpes have no idea they have the disease.

Females more so than males and Black people more than White people have a disproportionately higher prevalence of genital herpes. Though blood screening may not be advised, it is recommended to talk with a healthcare provider about how to prevent exposure and know if you should receive blood testing.

A Word From Verywell

If you are at risk of genital herpes, you need to take greater steps to avoid infection because condoms only provide partial protection. In the end, any area not covered by a condom still has the potential to spread the virus through skin-to-skin contact.

If you are sexually active, the best way to reduce your risk is to limit your number of sexual partners and use condoms consistently.

If you have herpes, you can reduce your chance of infecting others by avoiding sex during an outbreak or when you have early signs of an outbreak (such as tingling or burning at the site where outbreaks usually occur).

If you have frequent outbreaks, ask your healthcare provider if taking daily antiviral drugs (called herpes prophylaxis) can help. By keeping the virus under control, you are less likely to infect others.