Genital human papillomavirus (HPV) infection is a common sexually transmitted disease (STD) caused by human papillomavirus. This is a group of more than 100 viruses, at least 40 of which can infect the genital tissues.
Causes and Symptoms
HPV is spread by direct contact of infected tissue with uninfected tissue during vaginal, anal, or oral sex.
An estimated 50 percent of sexually active adults have been infected with one or more of the HPV types that cause genital infections. At any time, an estimated 20 million Americans have genital HPV infections. About 6.2 million Americans get a new genital HPV infection each year.
Most types of HPV that infect genital tissues do not cause any symptoms. Certain types of HPV cause genital warts that usually appear as soft, moist, pink, or red swellings that grow quickly.
Several types of genital HPV infection (not usually the types that cause warts) can increase the risk of cervical cancer in women and other genital cancers in both women and men. A small percentage of women with certain types of abnormal cells will develop cancer if these cells are not removed.
Frequent Pap smears and careful medical follow-up, with treatment if necessary, can help ensure that precancerous cells caused by HPV infection do not develop into life-threatening cervical cancer.
Other cancers that can be caused by HPV are less common than cervical cancer. Each year in the US, there are about:
- 1,500 women who get HPV-associated vulvar cancer
- 500 women who get HPV-associated vaginal cancer
- 400 men who get HPV-associated penile cancer
- 2,700 women and 1,500 men who get HPV-associated anal cancer
- 1,500 women and 5,600 men who get HPV-associated oropharyngeal cancers (cancers of the back of throat including base of tongue and tonsils) [Note:many of these cancers may also be related to tobacco and alcohol use.]
Certain populations are at a higher risk for some HPV-related health problems. This includes gay and bisexual men, and people with weak immune systems (including those who have HIV/AIDS).
RRP is very rare. It is estimated that less than 2,000 children get juvenile-onset RRP every year in the US.
Treatment can eliminate genital warts, but it does not necessarily eliminate genital HPV infection.
Prevention of HPV
How can people prevent HPV?
There are several ways that people can lower their chances of getting HPV:
- Vaccines can protect males and females against some of the most common types of HPV that can lead to disease and cancer. These vaccines are given in three shots. It is important to get all three doses to get the best protection. The vaccines are most effective when given at 11 or 12 years of age.
- Girls and Women: Two vaccines (Cervarix and Gardasil) are available to protect females against the types of HPV that cause most cervical cancers. One of these vaccines (Gardisil) also protects against most genital warts. Gardisil has also been shown to protect against anal, vaginal and vulvar cancers. Either vaccine is recommended for 11 and 12 year-old girls, and for females 13 through 26 years of age, who did not get any or all of the shots when they were younger. These vaccines can also be given to girls beginning at 9 years of age. It is recommended to get the same vaccine brand for all three doses, whenever possible.
- Boys and men: One available vaccine (Gardisil) protects males against most genital warts and anal cancers. This vaccine is available for boys and men, 9 through 26 years of age.
- For those who choose to be sexually active, condoms may lower the risk of HPV. To be most effective, they should be used with every sex act, from start to finish. Condoms may also lower the risk of developing HPV-related diseases, such as genital warts and cervical cancer. But HPV can infect areas that are not covered by a condom – so condoms may not fully protect against HPV.
- People can also lower their chances of getting HPV by being in a faithful relationship with one partner; limiting their number of sex partners; and choosing a partner who has had no or few prior sex partners. But even people with only one lifetime sex partner can get HPV. And it may not be possible to determine if a partner who has been sexually active in the past is currently infected. That’s why the only sure way to prevent HPV is to avoid all sexual activity.
CPC’s STATEMENT ON HPV VACCINE
A quadrivalent HPV (human papillomavirus) vaccine1 received FDA approval in June 2006. This vaccine is intended to provide immunity against four common HPV types — 16, 18, 6, & 11. It is marketed under the name Gardasil®. A bivalent HPV vaccine, intended to provide immunity against HPV types 16 and 18, received FDA approval in October 2009.2 It is marketed under the name Cervarix®.
Scientific evidence on immunization with the quadrivalent vaccine suggests that it:
- Substantially reduces the risk of pre-cancer and cancer of the cervix caused by HPV types 16 & 183,4,5 (responsible for ~70% of all cervical cancers in the US6)
- Substantially reduces the risk of genital warts caused by HPV types 6 & 117 (responsible for ~90% of all genital warts in the US8)
- Substantially reduces the risk of precancerous vulvar and vaginal lesions caused by HPV types 16 & 189
- Is cost effective when administered to adolescent females10
Scientific evidence on immunization with the bivalent vaccine suggests that it:
- Substantially reduces the risk of pre-cancer and cancer of the cervix caused by HPV types 16 & 1811 (responsible for ~70% of all cervical cancers in the US12)
However, there is no evidence to suggest that the vaccines:
- Are effective against HPV types that are present at the time of immunization13,14
- Reduce the risk of other sexually transmitted diseases (STDs)
- Offer any protection against the other consequences of nonmarital sexual activity such as pregnancy and emotional damage
- A few studies suggest that immunization may provide limited protection against precancerous lesions caused by other types of HPV15,16,17,18
- The duration of immunity following immunization is unknown19,20
- The role of the vaccine for males is under investigation21,22
- Promote abstinence for unmarried persons as a primary method to prevent pregnancy,23,24 STDs including HIV,25 and the emotional consequences of sexual activity26
- Promote monogamy as a primary method to prevent STDs including HIV27
- Support the development and widespread use of vaccines against HPV and other STDs
- Encourage further research into the duration of immunity and the optimal timing of immunization
- Recommend continued regular health screening and counseling including pelvic examinations, Pap tests, and appropriate STD screening
Finally, we encourage physicians to counsel all their patients regarding sexual health.
Centers for Disease Control and Prevention, Genital HPV Infection Fact Sheet 2011, http://www.cdc.gov/std/HPV/STDFact-HPV.htm
Koutsky, L. A., and Kiviat, N. B. (1999). “Genital Human Papillomavirus.” In Sexually Transmitted Diseases, 3rd edition, eds. K. Holmes, P. Mardh, P. Sparling et al. New York: McGraw-Hill.