Genital herpes spreads through skin-to-skin contact during vaginal, anal, or oral sex with someone who carries the virus. Around 846 million people between the ages of 15 and 49 are currently living with a genital herpes infection, making it one of the most common sexually transmitted infections worldwide. An estimated 42 million people acquire a new genital herpes infection every year.
Two types of herpes simplex virus cause genital infections: HSV-2, which is the more traditional cause, and HSV-1, the type most people associate with cold sores. Both can infect the genital area, and both spread even when no visible sores are present.
How HSV-2 Spreads During Sex
HSV-2 is the type most closely linked to genital herpes, with roughly 520 million people carrying a genital HSV-2 infection as of 2020. It transmits during sex through direct contact with genital or anal skin, sores, or fluids from an infected partner. The virus doesn’t need an open wound or visible outbreak to pass from one person to another. It can shed from skin that looks completely normal, and in fact, about 70% of transmissions occur during periods when the infected partner has no visible symptoms at all.
This “asymptomatic shedding” is one reason genital herpes spreads so effectively. A person can carry the virus for months or years without knowing it, passing it to partners who assume the encounter is risk-free. Shedding happens more frequently in the months and years closest to when someone first acquires the infection, and HSV-2 sheds from genital skin more often than HSV-1 does.
How Oral Sex Spreads HSV-1 to the Genitals
An increasingly recognized route of genital herpes is oral sex. When someone with oral HSV-1 (cold sores) performs oral sex, the virus can transfer from their mouth to their partner’s genitals. About 376 million people are estimated to have genital HSV-1 infections. The greatest risk is when the person giving oral sex has an active cold sore, but transmission can also happen when their mouth looks and feels perfectly normal.
This means you can get genital herpes from a partner who has never had a genital infection themselves. Many people with oral herpes contracted it in childhood through non-sexual contact and don’t think of themselves as having an STI. During oral sex, however, HSV-1 from saliva, lip skin, or the surrounding facial area can reach genital tissue and establish a new infection there.
What Makes Transmission More Likely
Several factors increase the chance of catching the virus during any given sexual encounter:
- Active sores or prodromal symptoms. The risk is highest when the infected partner has visible blisters, ulcers, or the tingling and burning sensation that often precedes an outbreak.
- Skin-to-skin contact beyond what condoms cover. Herpes sores can appear on the thighs, buttocks, and areas around the genitals that a condom doesn’t protect. The virus also sheds from these uncovered areas.
- Being female. Research shows that consistent condom use significantly reduces HSV-2 transmission to women but offers less measurable protection for men. The mucosal lining of the vagina and the larger surface area of exposed tissue likely make female partners more biologically susceptible.
- Recent infection in the transmitting partner. Asymptomatic shedding is more frequent in the period shortly after someone first acquires herpes, so a partner with a newer infection sheds the virus more often than someone who has carried it for years.
Can You Get It From Toilet Seats or Towels?
Herpes simplex virus can survive on dry surfaces for anywhere from a few hours to several weeks, with longer survival at lower humidity. That said, real-world, non-sexual transmission through objects like toilet seats or shared towels is considered extremely unlikely. The virus requires direct contact with mucous membranes or broken skin to establish an infection, and the amount of virus surviving on a surface drops quickly compared to what’s present during skin-to-skin contact. The practical risk from inanimate objects is negligible.
Why People Often Don’t Know They Have It
One of the most important things to understand about genital herpes is that most people who carry it are unaware. Many infections produce no symptoms at all, or symptoms so mild they’re mistaken for ingrown hairs, razor burn, or yeast infections. Of the 846 million people with genital herpes globally, only about 200 million experienced at least one symptomatic episode in 2020. That means the majority of carriers never have a recognizable outbreak.
When symptoms do appear for the first time, they typically show up within two weeks of exposure. Some people, however, don’t have a noticeable first outbreak until months or even years after contracting the virus, making it difficult to pinpoint when or from whom they caught it.
How Testing Works After Exposure
If you think you’ve been exposed, timing matters for testing. Blood tests detect antibodies your immune system produces in response to the virus, but these antibodies take time to build up. After exposure, current blood tests can take up to 16 weeks or more to reliably detect the infection. Testing too early can produce a false negative. If you have visible sores, a swab test of the sore itself can identify the virus more quickly and is generally more reliable during an active outbreak.
Reducing the Risk of Transmission
Condoms lower the risk but don’t eliminate it, because the virus sheds from skin that condoms don’t cover. For women receiving penetrative sex, consistent condom use provides significant protection against HSV-2. The benefit is less clear-cut for male partners, likely because of the broader skin-to-skin contact that occurs regardless of condom use.
When the infected partner takes a daily antiviral medication, transmission rates drop further. In studies of couples where one partner had genital HSV-2, daily suppressive therapy reduced the rate of passing the virus to the uninfected partner. Combining daily antivirals with condom use offers the strongest available protection short of abstaining from contact during outbreaks.
Avoiding sexual contact during active outbreaks, including the tingling or itching phase that precedes visible sores, is one of the most effective single steps. Since the virus is most contagious when sores are present, skipping contact during these periods removes the highest-risk window. It’s also possible to have both HSV-1 and HSV-2 at the same time, so protection matters even if you already carry one type.