Thehuman papillomavirus is transmitted by direct, intimate person-to-person contact. In virtually all cases, that contact is sexual.
HPV is extremely common. About 20 million Americans are currently infected with the virus, and about 50% of sexually active men and women will acquire the infection at some time in their lives.
There are over 100 types of HPV. Many people who are infected don’t have any symptoms, but many others develop genital warts, or condylomas, which are soft flesh-colored swellings in the genital or rectal areas. Genital warts often respond to topical treatments, and some resolve without therapy.
Some strains of HPV can cause cancer. Women infected with HPV 16 or HPV 18 are at risk for cervical cancer. Fortunately, regular Pap tests can detect precancerous cells or early, highly curable cancers. Once a woman has contracted HPV, her best defense against serious illness is to have a yearly Pap test. Much less often, men infected with so-called high-risk strains of HPV can develop penile or anal malignancies.
Safer sexual practices, including the proper use of latex condoms, can help prevent infection in the first place, but since the virus can spread from areas of the skin that are not covered by a condom, protection is not complete.
In 2006, the FDA approved the Gardasil vaccine for girls and women between the ages of 9 and 26 years. The vaccine contains 2 low-risk strains (HPV 5 and 11) and 2 high-risk strains (HPV 16 and 18) that account for 70% of cervical cancers and 90% of genital warts. The vaccine has not yet been approved for males in the U.S.
Finally, in answer to your hard question, everyone with HPV caught it from someone else.