The human papillomavirus, or HPV, is one of the most common families of viruses, and it also causes the most prevalent sexually transmitted infection. It is transmitted by skin-to-skin contact. HPV is comprised of over 100 identified viruses, 30 strains of which are sexually transmitted. According to HPVSafety.com, more than 75% of the population has been infected with one of the HPV viruses.
Low-Risk HPV Strains: Non-Genital
Several kinds of warts are caused by strains of the HPV virus, including plantar warts, common warts, and skin tags. These are low-risk varieties of HPV that can occur anywhere on the body and are generally harmless. Although there is no cure for HPV infection, the body's immune system often clears the infection and the warts and lesions caused by HPV go away on their own. Warts that persist can be managed successfully. Warts and lesions are often treated with prescription creams, cryosurgery, the removal of the wart with a heated instrument, or common surgery.
Low-Risk HPV Strains: Genital
Genital warts are the most common result of HPV, and many strains of HPV that cause genital warts are considered low risk. These strains may cause a Pap smear to appear irregular, but they are not associated with cancer. Both women and men can become infected by low-risk HPV strains and not know it because they may not exhibit physical symptoms. Genital warts can appear weeks or even years after contact with someone infected with HPV. It is rare, but low-risk HPV strains can cause warts in the throat or mouth after oral sex with an infected person.
High-Risk HPV Strains: Genital
According to Rutgers University, there are approximately 13 high-risk strains of HPV, all of which are sexually transmitted. Two of those strains, strains 16 and 18, are thought to cause 70% of all cervical cancer cases. As with low-risk strains, there is no cure for HPV. In 2006 the U.S. Food and Drug Administration approved a vaccine that protects against four of the highest risk HPV strains, types 6, 11, 16 and 18. It is recommended for girls and women between the ages of 9 and 26. The U.S. Centers for Disease Control and Prevention recommend women get regular Pap tests to screen for HPV. Aside from developing warts, men generally do not develop further health problems from HPV infection and are currently not approved to take the HPV vaccine. The National Cancer Institute notes that there may be an association between HPV and some cancers of the anus, vulva, vagina, and penis.
