An estimated 47 million people in the United States have HSV-2, the virus most commonly responsible for genital herpes. That works out to roughly 12% of Americans between ages 14 and 49, or about one in eight people in that age group. Despite how common it is, the vast majority of those carrying the virus don’t know they have it.
The Numbers in Context
The most reliable U.S. data comes from the National Health and Nutrition Examination Survey (NHANES), which tests blood samples from a representative slice of the population. In the 2015–2016 survey cycle, 12.1% of people aged 14 to 49 tested positive for HSV-2 antibodies. Applied to the current U.S. population in that age range, that translates to roughly 47 million people living with the infection.
On top of that existing pool, an estimated 647,000 new HSV-2 infections occur each year. That number has actually fallen from a peak of about 1 million new infections per year in the late 1970s, but it still means hundreds of thousands of people acquire the virus annually.
Rates Have Been Dropping for Decades
HSV-2 prevalence has declined steadily since the turn of the century. In 1999–2000, 18% of Americans aged 14 to 49 tested positive. By 2015–2016, that had fallen to 12.1%, a drop of nearly six percentage points. The decline showed up across every racial and ethnic group tracked in the survey: prevalence among non-Hispanic white adults fell from 14.1% to 8.1%, among non-Hispanic Black adults from 41.5% to 34.6%, and among Mexican-American adults from 12.8% to 9.4%.
Researchers attribute the decline partly to changes in sexual behavior and partly to fewer young people entering adulthood with HSV-1 (the “cold sore” virus), which can offer some partial cross-protection against HSV-2 acquisition. Still, even with the downward trend, the virus remains deeply embedded in the population, and modeling projections suggest over 600,000 new infections will continue to occur each year through at least 2050.
Who Is Most Affected
HSV-2 doesn’t spread evenly across the population. Women are infected at roughly twice the rate of men, largely because the virus transmits more efficiently from men to women during sex. Age matters too: prevalence is lowest among teenagers and rises steadily through adulthood as cumulative sexual exposure increases.
The most striking disparity is racial. Non-Hispanic Black adults have an HSV-2 prevalence of 34.6%, more than four times the rate among non-Hispanic white adults (8.1%). This gap is not explained by differences in individual sexual behavior. It reflects how infections circulate within sexual networks: when background prevalence is already high in a community, any given sexual encounter carries a higher probability of exposure regardless of how many partners a person has.
Most People Don’t Know They’re Infected
Perhaps the most important number for anyone reading this: up to 90% of people with HSV-2 are unaware they carry the virus. Some never develop noticeable symptoms. Others experience mild or atypical symptoms, like small skin irritations or what looks like an ingrown hair, that never prompt a doctor’s visit. Without a blood test, these infections go unrecognized.
This matters because people who don’t know they’re infected can still transmit the virus, particularly through asymptomatic viral shedding, periods when the virus is active on the skin’s surface without causing visible sores. In couples where one partner has HSV-2 and the other doesn’t, the annual transmission risk can be significant. One study found that women without any prior herpes antibodies had a 31.8% annual risk of acquiring the virus from an infected male partner, while women who already carried HSV-1 antibodies had a lower risk of about 9.1%, suggesting some degree of cross-protection.
Why Routine Testing Isn’t Recommended
Given how common HSV-2 is and how few people know they have it, you might assume widespread screening would be standard. It isn’t. The U.S. Preventive Services Task Force actively recommends against routine blood testing for genital herpes in people without symptoms, giving it a “D” grade, meaning the task force concluded with moderate certainty that the harms of screening outweigh the benefits.
The reasoning comes down to test accuracy and psychological impact. The most widely available blood tests for HSV-2 produce a meaningful rate of false positives, especially in people with a low probability of infection. A false positive result can cause significant distress, damage relationships, and lead to unnecessary treatment, all without improving health outcomes. For someone with no symptoms and no known exposure, the test creates more problems than it solves.
This recommendation doesn’t apply to people who have symptoms, a known exposure, or HIV. In those cases, testing is appropriate and can guide treatment decisions. But for the general population, the current guidance is to test only when there’s a clinical reason to do so.
HSV-1 Is Changing the Picture
The conversation about genital herpes has shifted in recent years because HSV-1, traditionally associated with oral cold sores, now causes a growing share of new genital herpes cases, particularly among young adults. Globally, about 92% of symptomatic genital herpes episodes are still linked to HSV-2, but in some Western countries the proportion caused by HSV-1 has risen substantially as fewer young people acquire oral HSV-1 in childhood and instead encounter it for the first time through oral sex.
This means the 47 million figure for HSV-2 doesn’t capture the full scope of genital herpes in the U.S. An unknown additional number of people have genital infections caused by HSV-1, which are not reflected in HSV-2 seroprevalence surveys. Genital HSV-1 tends to recur less frequently than genital HSV-2 and sheds less virus between outbreaks, but it can still be transmitted to partners and can cause significant first-episode symptoms.