Yes, HPV (human papillomavirus) is the most common sexually transmitted infection in the United States and worldwide. About 13 million Americans pick up a new HPV infection every year, and more than 42 million are currently infected with disease-causing types. The numbers dwarf every other STI by a wide margin.
The lifetime probability of getting HPV tells the story even more clearly. Among people who have had at least one sexual partner, an estimated 85% of women and 91% of men will acquire HPV at some point. For those with 15 or more lifetime partners, that figure rounds to 100%. No other sexually transmitted infection comes close to that reach.
How HPV Compares to Other STIs
CDC estimates from 2018 found that roughly one in five Americans, about 20% of the population, had a sexually transmitted infection on any given day. Of all prevalent and new STI cases that year, four infections accounted for the overwhelming majority: chlamydia, trichomoniasis, genital herpes, and HPV. Together they represented 98% of all existing STI cases and 93% of all new ones. HPV alone sits at the top of that list because of how easily it spreads through skin-to-skin contact, not just intercourse, and because there are so many different strains circulating at once.
For comparison, chlamydia is the most commonly reported bacterial STI, with roughly 1.8 million cases reported to the CDC annually. Gonorrhea and syphilis add hundreds of thousands more. But HPV’s 13 million new infections per year dwarfs those numbers. The key difference is that HPV is a virus that often produces no symptoms, so most people carry and transmit it without ever knowing.
Who Gets Infected and When
HPV hits hardest in young adulthood, though the timing differs slightly between men and women. Among women, infection peaks in the early 20s, with nearly 63% of sexually experienced 20- to 24-year-olds testing positive for at least one HPV type. For men, prevalence peaks a bit later, in the late 20s, when about 52% of 25- to 29-year-olds carry the virus. These differences likely reflect patterns in sexual behavior and immune response rather than any biological resistance.
After these peak years, prevalence drops in women as their immune systems clear infections. In men, rates stay relatively flat across older age groups, a pattern researchers don’t fully understand.
Over 200 Strains, but Only Some Are Dangerous
Part of what makes HPV so widespread is its sheer diversity. Scientists have identified more than 200 distinct types, and they fall into two broad categories based on their health effects.
- Low-risk types (like types 6 and 11) can cause genital warts and minor cervical cell changes but don’t lead to cancer.
- High-risk types (like types 16 and 18) can trigger cell changes that, if they persist, develop into cancer of the cervix, throat, anus, or other areas.
National surveys from 2013 to 2014 found that about 40% of U.S. women and 45% of U.S. men aged 18 to 59 were carrying at least one detectable HPV type at the time of testing. Roughly half of those infections involved high-risk strains: 20% of women and 25% of men had a cancer-causing type. Being infected with a high-risk strain doesn’t mean cancer is inevitable, but it does mean the immune system needs to clear the virus before lasting damage occurs.
Most Infections Clear on Their Own
The reassuring reality is that 80% to 90% of HPV infections are transient. Your immune system recognizes and eliminates the virus within about two years of first detection, often without you ever knowing you were infected. You won’t feel sick, and there’s nothing to treat during this window.
The remaining 10% to 20% of infections that persist are the ones that matter medically. When the immune system fails to clear a high-risk strain, the virus can slowly alter cells over years or even decades. That long timeline is why cervical screening programs work so well: there’s a wide window to catch precancerous changes before they progress. On a cellular level, persistent infections appear to involve an impaired immune response at the site of infection, though researchers are still working out exactly why some people’s immune systems struggle with specific strains.
The Cancer Connection
Globally, HPV-related cancers accounted for about 1.5 million new cases in 2022, representing roughly 7.5% of all cancers diagnosed that year. Cervical cancer made up 44% of those cases (about 662,000), while head and neck cancers contributed another 45.5% (about 685,000 cases). The rest included cancers of the anus, vulva, vagina, and penis.
In the United States specifically, HPV causes about 36,000 cancer cases per year. This is a significant burden, but it’s important to keep it in proportion: with tens of millions of active infections, only a tiny fraction lead to cancer. The path from infection to cancer typically takes 10 to 20 years, giving the immune system and medical screening multiple opportunities to intervene.
Vaccination Has Changed the Picture
The HPV vaccine, introduced in 2006, targets the strains responsible for most HPV-related cancers and genital warts. Its impact has been dramatic. Among teenage girls in the United States, infections with vaccine-targeted HPV types have declined 88% since the vaccine became available. That translates directly into fewer precancerous lesions and, as vaccinated generations age, is expected to sharply reduce HPV-related cancer rates.
The vaccine works best when given before any exposure to the virus, which is why it’s recommended for preteens. But it provides meaningful protection for anyone up to age 26 who hasn’t been vaccinated, and it’s approved for adults up to 45 who may benefit based on their risk. Even after vaccination, HPV remains the most common STI overall because the vaccine covers specific high-risk and low-risk types rather than all 200-plus strains. Still, protecting against the most dangerous strains is what matters for cancer prevention.
Despite being nearly universal among sexually active adults, HPV is also the only STI with a highly effective vaccine that prevents the most serious health consequences. That combination of extreme prevalence and strong preventability makes it unlike any other sexually transmitted infection.