Process
HPV is the acronym for (genital) human papillomavirus, the most commonly transmitted sexual infection. Like other viruses, HPV cannot reproduce on its own but must get inside another host cell and take it over. There are 40 varieties that infect the genitalia of men and women, but they often go undetected. They are considered to be low-risk if they cause genital warts and high-risk if they cause cervical or other less common genital cancers. Ninety percent of the time, the human immune system can fight off high- or low-risk HPV without help.
Transmission
HPV is passed on to others through direct contact with mucous membranes or breaks in the skin during vaginal or anal sex. Because of the prolonged gestation period and often lack of any symptoms, a carrier could have active HPV for years after no longer having sexual contact. Much more rarely, a mother giving birth could give it to her child as the baby goes through the birth canal.
Frequency
According to the Centers for Disease Control and Prevention, about 20 million Americans are infected with HPV, and 6.2 million more are infected yearly. Half of all sexually active men and women get the genital HPV infection at some point in their lives.
Prevention
A vaccine is available to protect females from HPVs that cause most cervical cancers and genital warts. The vaccine is recommended for young women from age 11 through 26 who haven't been vaccinated. Condoms may also protect against some HPVs, but any sexual contact may allow transmission.
