What is HPV?
Genital HPV infection is a sexually transmitted disease (STD) that is caused by human papillomavirus (HPV). Human papillomavirus is the name of a group of viruses that includes between 70 and 100 different strains or types. About 40 types of HPV can infect the genital area - the vulva, vagina, cervix, rectum, anus, penis, or scrotum.
• Some types may cause genital warts. These are called low-risk types.
• Some types may cause cell changes that sometimes lead to cervical and certain other genital and throat cancers. These are called high-risk types. They do not usually have visible symptoms.
• Most types seem to have no harmful effect at all.
More than 30 of these viruses are sexually transmitted, and they can infect the genital area of men and women including the skin of the penis, vulva (area outside the vagina), or anus, and the linings of the vagina, cervix, or rectum. Most people who become infected with HPV will not have any symptoms and the infection will clear up on its own.
Some of these viruses are called "high-risk" types, and may cause abnormal Pap tests. They may also lead to cancer of the cervix, vulva, vagina, anus, or penis. Others are called "low-risk" types, and they may cause mild Pap test abnormalities or genital warts.
How common is HPV infection?
Genital HPV infections are very common among sexually active people. At any time about 20 million people in the U.S. have them. Between 10 and 15 million have high-risk types that are associated with cervical cancer. HPV is so common that about three out of four people have HPV at some point in their lives. But most people who have it don't know it.
How do people get genital HPV infections?
The types of HPV that infect the genital area are spread primarily through genital contact. Vaginal and anal intercourse spread genital HPV infections. In some cases, other kinds of skin-to-skin contact, including sex play, such as body rubbing and oral sex, may also transmit HPV.
Anyone who has ever had genital contact with another person may have HPV. Both men and women may get it -- and pass it on-- without knowing it. Since there might not be any signs, a person may have HPV even if years have passed since he or she had sex.
What are the signs and symptoms of genital HPV?
Most people who have a genital HPV infection do not know they are infected. The virus lives in the skin or mucous membranes and usually causes no symptoms. Some people get visible genital warts, or have pre-cancerous changes in the cervix, vulva, anus, or penis. Very rarely, HPV infection results in anal or genital cancers.
Genital warts usually appear as soft, moist, pink, or flesh-colored swellings, usually in the genital area. They can be raised or flat, single or multiple, small or large, and sometimes cauliflower shaped. They can appear on the vulva, in or around the vagina or anus, on the cervix, and on the penis, scrotum, groin, or thigh. After sexual contact with an infected person, warts may appear within weeks or months, or not at all.
Genital warts are diagnosed by visual inspection. Visible genital warts can be removed by medications the patient applies, or by treatments performed by a health care provider. Some individuals choose not to get treatment to see if the warts will disappear on their own. No treatment regimen for genital warts is better than another, and no one treatment is ideal for all cases.
How is genital HPV infection diagnosed?
Most women are diagnosed with HPV on the basis of abnormal Pap tests. A Pap test is the primary cancer-screening tool for cervical cancer or pre-cancerous changes in the cervix, many of which are related to HPV. Also, a specific test is available to detect HPV DNA in women. The test may be used in women with mild Pap test abnormalities, or in women older than 30 years of age at the time of Pap testing. The results of HPV DNA testing can help health care providers decide if further tests or treatment are necessary. No HPV tests are available for men.
How is HPV treated?
There is currently no treatment to cure HPV itself. Most types of HPV infection are harmless, do not require treatment, and go away by themselves. Treatment is available for the abnormal cell changes caused by HPV. The treatments provided are targeted to the changes in the skin or mucous membrane caused by HPV infection, such as warts and pre-cancerous changes in the cervix.
The American College of Obstetricians and Gynecologists recommend that sexually active women and women age 21 and older have an annual gynecologic exam in addition to Pap tests at regular intervals (the frequency of Pap tests can vary depending on a woman's age and the type of Pap test being done).
Ho GYF, Bierman R, Beardsley L, Chang CJ, Burk RD. Natural history of cervicovaginal papilloma virus infection in young women. N Engl J Med 1998;338:423-8.
Koutsky LA, Kiviat NB. Genital human papillomavirus. In: K. Holmes, P. Sparling, P. Mardh et al (eds). Sexually Transmitted Diseases, 3rd edition. New York: McGraw-Hill, 1999, p. 347-359.