Genital Warts and Human Papilloma Virus

Papillomas, or warts, are caused by papillomaviruses. There are more than 80 types of human papillomaviruses (HPV), and although unpleasant, the warts caused by most are common, harmless and easily treated.

Warts are generally categorized based on the area of the body on which they are found:* Seed warts - found on fingers and toes
* Plantar warts - found on the soles of feet
* Flat warts - found on trunk, face, elbows or knees
* Genital warts - found on the external genitalia

Genital Warts and HPV

About forty types of human papillomaviruses cause genital warts, an infection transmitted through the skin or mucous membranes during sexual intercourse. Once a person is infected, it typically takes three to four months for symptoms to manifest. However most of the time, genital HPVs show no symptoms, or lead to warts that are very small, so those infected may be entirely unaware. Genital warts are currently one of the most common sexually transmitted diseases, with approximately 500,000 new cases reported annually in the United States.

Since the virus often shows no symptoms, what's the big deal? Cancer. A few varieties of sexually transmitted HPV have been linked to cancers of the anus, vagina, penis, and oral cavity, and nearly all cervical cancers are the result of HPV infection.

Types of HPV Linked to Cancer

HPV types 6 and 11 produce cancer-associated genital warts that are highly visible, as cauliflower-like eruptions called condylomata acuminatum (con-di-LOW-mah-teh ah-cue-mi-NAH-tah). However, there are other forms of sexually transmitted HPV that give rise to flat or nearly invisible warts, including HPV-16, HPV-18, HPV-31, and HPV-45. Up to 95% of cervical cancers are caused by HPV-16 and HPV-18, and recent studies reveal that these two types are linked to HPV oral cancers as well.

Vaccination Against HPV

Gardasil ®, by Merck, was the first vaccine developed for the prevention of genital warts and cervical cancer due to HPV, and GlaxoSmithKline (GSK) is currently awaiting FDA approval for their new HPV vaccine called Cervarix ®.

The Centers for Disease Control (CDC) recommends that the HPV vaccine ideally be administered to all 11- and 12-year-old girls, as well as to females aged 13 through 26 years who have not been previously vaccinated or who have not completed the full series of shots. In October of 2009 HPV vaccine was also indicated for boys.

Gardasil ® is given in a series of three injections over a six-month period. It has shown to be highly effective in preventing four types of HPV in young women previously unexposed to HPV, targeting the HPV types that cause approximately 70% of all cervical cancers and 90% of genital warts. The vaccine is used only for prevention and will not treat existing HPV infections.

Additional InformationBauman, Robert W. (2004) Microbiology. Pearson Benjamin Cummings
CDC HPV VaccinationOral Cancer Foundation - The Human Papilloma Virus

* This article originally appeared in Suite101 online magazine.