About 13% of people worldwide between ages 15 and 49 have genital herpes caused by HSV-2, the virus most commonly associated with the condition. That translates to roughly 520 million people globally. In the United States, the numbers are similar: an estimated 18.6 million adults aged 18 to 49 are living with genital herpes, and around 572,000 new cases occur each year.
Global and U.S. Prevalence
A 2020 mathematical modeling analysis published in the BMJ’s Sexually Transmitted Infections journal estimated that 519.5 million people aged 15 to 49 had existing HSV-2 infections worldwide, putting global prevalence at 13.3%. That same year, an estimated 25.6 million people in that age group were newly infected.
In the U.S., CDC data from the National Health and Nutrition Examination Survey (NHANES) found that about 12% of Americans aged 14 to 49 tested positive for HSV-2 through blood tests. These figures only capture HSV-2. Genital herpes can also be caused by HSV-1 (the virus traditionally linked to cold sores), which is increasingly responsible for genital infections through oral sex. When HSV-1 genital cases are included, the true number of people with genital herpes is higher than HSV-2 statistics alone suggest.
Women Are Infected at Nearly Twice the Rate
The gap between men and women is striking. In the U.S., 15.9% of women aged 14 to 49 tested positive for HSV-2 compared to 8.2% of men. That means roughly 1 in 6 women carries the virus versus about 1 in 12 men. The difference is largely biological: the thin mucosal tissue of the vagina and vulva is more susceptible to infection during sexual contact, giving the virus an easier entry point. Longer exposure time during intercourse also plays a role, as the virus transmits more efficiently from men to women than the reverse.
Most People Don’t Know They Have It
Perhaps the most important number for anyone searching this topic: an estimated 81% of Americans with HSV-2 have never been diagnosed and don’t know they’re infected. That’s more than 4 out of 5 people carrying the virus. Many never develop the classic painful blisters that people associate with herpes, or their symptoms are so mild they get mistaken for ingrown hairs, razor burn, or yeast infections.
This matters because the virus can still spread even without visible sores. HSV sheds from the skin intermittently, meaning the virus is present on the surface and can be transmitted to a partner on days when no outbreak is happening. Shedding rates vary enormously from person to person, ranging from essentially zero to over 90% of days tested in some individuals. On average, people with HSV-2 shed the virus asymptomatically on roughly 10 to 20% of days, which is why transmission between partners often happens when neither person realizes the virus is active.
Prevalence Increases With Age
Because HSV-2 is a lifelong infection (the virus stays dormant in nerve cells and is never fully cleared), prevalence rises steadily with age. Rates among teenagers and young adults in their early 20s are relatively low, then climb through the 30s and 40s as people accumulate more years of sexual activity and potential exposure. By the time people reach their 40s, infection rates are substantially higher than in younger age groups. This cumulative pattern is why statistics focused on adults up to age 49 capture the bulk of infections but likely undercount the total number of people living with the virus, since older adults aren’t always included in surveillance data.
Why Standard STI Testing Doesn’t Include Herpes
One reason so many people are unaware of their status is that herpes blood testing is not part of routine STI screening in the U.S. The CDC does not recommend universal HSV-2 screening for people without symptoms. The reasoning is partly practical: blood tests for herpes can produce false positives, especially at low antibody levels, and a positive result in someone who has never had symptoms can cause significant psychological distress without a clear clinical benefit. Testing is typically reserved for people who have active sores that can be swabbed, those whose partners have a known herpes diagnosis, or those who specifically request it.
This screening policy contributes directly to the 81% undiagnosed figure. If you want to know your status, you generally need to ask for the test by name, as it won’t be included automatically even when you request a “full panel” for sexually transmitted infections.
Putting the Numbers in Perspective
Genital herpes is one of the most common sexually transmitted infections on the planet, yet it carries a stigma disproportionate to its medical impact. For most people, HSV-2 causes occasional outbreaks that become less frequent over time, and many people experience no noticeable symptoms at all. Antiviral medications can reduce outbreak frequency and cut transmission risk to partners roughly in half. Condoms further lower the risk, though they don’t eliminate it entirely since the virus can shed from skin not covered by a condom.
The core takeaway from the data is that genital herpes is far more common than most people assume. With roughly 1 in 8 people globally and a similar proportion of Americans carrying HSV-2, and the majority unaware of it, the infection is widespread enough that most sexually active adults have been exposed to someone with the virus, whether or not transmission occurred.