The human papilloma virus, or HPV, infects the skin and mucosa such as genitalia and mouth. A study published in the February 2007 issue of the "Journal of the American Medical Association" showed that 26.8 percent of women in the United States between ages 14 to 59 were infected with HPV. In the majority of cases, the immune system will eliminate the virus, though it may take years. There are viruses which infect the skin and others which infect the genitalia, and they can be further subdivided into high-risk and low-risk HPV.
Low-Risk HPV of the Skin
A number of HPV types, for example, HPV 1, 2, 3, 4, 27, 29 and 57 cause warts and verrucas. They usually occur in people under age 18, or in people who have a suppressed immunity. A study published in the December 2000 issue of the "Journal of Virology", showed that not only were renal transplant patients infected with asymptomatic HPV skin infections, but 80 percent of healthy individuals were positive for HPV on their skin. Warts often occur on the hands or as verrucas on the soles of the feet. They are spread by direct touch or from moist surfaces such as swimming pool floors. They are usually asymptomatic, but can be large and unsightly.
Low-Risk Genital HPV
Genital warts are the most common sexually transmitted disease, and incidences are on the rise. Mucosal HPVs usually infect the genitalia and are transmitted through sexual intercourse or maternal transmission. HPV 6 or HPV 11 cause the majority of genital warts. They can vary in size and color and can occur in the mouth after oral sex. Removal of symptomatic warts can result in recurrence several months later.
High-Risk HPV
High-risk HPVs include HPV 16, 18, 31, 33, 39, 45, 52 and 58. They are linked to a number of cancers such as that of the vulva, cervix and mouth. A study published in the March 2006 issue of the "Journal of Clinical Virology", showed that 89.9 percent of cancers of the cervix contained high-risk HPVs.
These high-risk HPVs increase the risk of cancer as two HPV genes bind and inactivate certain genes in the human cell. This inactivation causes the human cell to divide even if the cell has damaged genetic material. However, though high-risk HPVs increase the risk of cancer, other factors also appear to play a role such as smoking, immune suppression, use of the oral contraceptive pill for over four years and the number of sexual partners.
References
- "Journal of the American Medical Association"; Prevalence of HPV Infection Among Females in the United States; Eileen F. Dunne; February 2007
- "Journal of Virology"; The Ubiquity and Impressive Genomic Diversity of Human Skin Papillomaviruses Suggest a Commensalic Nature of the Viruses; Annika Antonsson; December 2000
- "Journal of Clinical Virology"; Associations of High-risk HPV Types and Viral Load with Cervical Cancer in China; Y. Wu; March 2006
