Information About the Human Papillomavirus (HPV)

Infection with the HPV virus infects at least 50% of all people who have sex at some time in their lives. Often, people don't have any symptoms and the HPV infection goes away on its own. Some types of HPV can lead to cervical cancer or cancer of the anus or penis.

Facts About HPV

HPV stands for human papillomavirus (pronounced pap ah LO mah), but there are actually more than 100 related viruses in this group. Each HPV virus is given a number or type. The term "papilloma" refers to a kind of wart that results from some HPV types.

HPV lives in the body's epithelial cells. These are flat and thin cells found on the skin's surface and also on the surface of the vagina, anus, vulva, cervix, penis head, mouth, and throat.

Of the 100 HPV types, about 60 types cause warts on areas such as the hands or feet. The other 40 or so types of HPV are sexually transmitted and are drawn to the body's mucous membranes, such as the moist layers around the anal and genital areas.

How HPV Spreads

These sexually-transmitted HPV viruses are spread through contact with infected genital skin, mucous membranes, or bodily fluids, and can be passed through intercourse and oral sex. HPV can infect skin not normally covered by a condom, so using a condom does not fully protect someone from the virus. Also, many people don't realize they're infected with HPV and may have no symptoms, so neither sexual partner may realize that the virus is being spread.

High-Risk HPV, Low-Risk HPV

Not all of the 40 sexually transmitted HPV viruses cause serious health problems. High-risk HPV strains include HPV 16 and 18, which cause about 70% of cervical cancers. Other high-risk HPV viruses include 31, 33, 45, 52, 58, and a few others.

Low-risk HPV strains, such as HPV 6 and 11, cause about 90% of genital warts, which rarely develop into cancer. Genital warts can look like bumps or growths. Sometimes they are shaped like cauliflower. The warts can show up weeks or months after exposure to an infected sexual partner.


How Common Is HPV?

About 80 million people in the U.S. are infected with HPV at any time, according to the CDC. And three-fourths of sexually active people between ages 15 and 49 have been infected at some point in their lives, according to estimates from the American Social Health Association.

You're more likely to get HPV if you:

  • Have sex at an early age
  • Have many sex partners
  • Have a sex partner who has had multiple partners

While many people think HPV is mostly a problem for teens or young adults, HPV can infect men and women of any age. In fact, the latest statistics from the CDC found that:

  • 19% of women ages 50 to 59 were infected with HPV virus
  • 27% of women ages 20 to 24 were infected with HPV virus
  • 45% of women ages 14 to 19 were infected with HPV virus

What Happens During HPV Infection

Often, there are no symptoms of an HPV infection and the body clears the infection on its own over the course of a few years. Some people never know they were infected. In fact, research has found that about 90% of women infected with HPV show no traces of the virus within two years.

When an HPV infection with high-risk types persists, it can cause abnormal changes in the cells of the cervix which could lead to cancer. Rarely, it may cause abnormal changes in penile and anal cells.

Reducing the Risk of Getting HPV

The only way to absolutely avoid the risk of HPV infection is to abstain from sex. You can also limit the number of sexual partners you have. And you can choose partners who've had few or no sexual partners before you. However, while a long-term monogamous relationship lowers your risk, it's important to remember that many people are infected and never know it.

There are three vaccines to protect against HPV which are available to boys and girls as young as nine and adults up to age 26. It is believed that overtime, the vaccines Cervarix, Gardasil, and Gardasil-9 will help reduce the spread of the HPV virus. Each protects against HPV 16 and 18, while Gardasil and Gardasil-9 are also effective against HPV 6 and 11 which cause 90% of all genital warts. Gardasil-9 also covers against the high risk strains: 31, 33, 45, 52, 58.

WebMD Medical Reference Reviewed by Jennifer Robinson, MD on December 06, 2015


SOURCES: Diane Harper, MD, MPH, professor of community and family medicine and obstetrics and gynecology, Dartmouth Medical School, Hanover, N.H. Joseph Bocchini, MD, chairman, committee on infectious diseases, American Academy of Pediatrics; chief of pediatric infectious diseases, Louisiana State University Health Sciences Center, Shreveport, La. American Cancer Society: "Frequently Asked Questions About Human Papilloma Virus (HPV) Vaccines." Dunne, E. Journal of the American Medical Association, February 28, 2007. FDA: "HPV (human papillomovirus)." CDC: "HPV and Men," "Genital HPV Infection-CDC Fact Sheet." American Social Health Association: "HPV (Human Papillomavirus) Fast Facts," "HPV (Human Papillomavirus) Background Information." National Institute of Allergy and Infectious Diseases: "Human Papillomavirus and Genital Warts."

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