Genital warts: Who gets and causes

Who gets genital warts?

Anyone who has sex can get human papillomavirus (HPV), the virus that causes genital warts. At least half of people who have sex have had an HPV infection. It is most common before age 30.

Not everyone who gets an HPV infection gets genital warts. Most people never get these warts because the body’s immune system fights the virus. Most people get rid of the virus in a few years and then are no longer contagious.

People who have a weakened immune system may not be able to fight the virus. When the body cannot fight HPV, genital warts can grow. A person’s immune system can become weak from a disease such as cancer or AIDS. Some medicines, such as those to prevent organ rejection, also weaken the immune system.

Research has found that smokers have a higher risk for getting genital warts than people who do not smoke. It is not clear why.

Sometimes a child gets genital warts. It is rare, but an infected mother can pass the virus to her baby during childbirth. The warts may not show up right away. Genital warts in a child also can be a sign of sexual abuse.

What causes genital warts?

Genital warts spread from a person who has HPV to another person through:

• Sex (vaginal, anal, or oral)

• Genital contact (people's genitals touch)

• Childbirth (from infected mother to baby)

Warts may not appear until weeks or months after sex with an infected person.