Genital human papilloma virus (HPV) is the most common sexually transmitted infection in the United States. An estimated 6.2 million persons are newly infected every year. This report comes from the Advisory Committee on Immunization Practices at the National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, based in Atlanta, Ga. The committee suggests that all females, aged nine to 26, be vaccinated against the genital HPV infection. Some states have made it mandatory for young girls as well as older young women to receive the vaccine to prevent infection by HPV.
The majority of the HPV infections cause no clinical symptoms initially because they are self-limited. But, persistent genital HPV infection can cause cervical cancer in women, and other types of genital cancers and genital warts in both men and women. Besides cervical cancer, HPV infection is also associated with other “anogenital” cancers of the vulva, vagina, penis and anus. These HPV-induced cancers are less common than cervical cancer. It is also found that some research studies support finding an HPV-caused subset of cancers both in the oral cavity and pharynx.
In June 2006, the HPV vaccine, Gardasil, was manufactured by Merck. It was licensed for use among females, aged nine to 26, to prevent HPV-related cervical cancer, and its precursors, vaginal and vulva cancers and genital warts. There are ongoing studies for use of the vaccine for HPV infections in males.
In the US, cervical cancer prevention and control programs have reduced the number of cervical cancer cases and death through cervical cytology screening, which can detect precancerous lesions. The HPV vaccine will not eliminate the need for cervical cancer screening in the U.S. because not all types of cervical cancers are included in the HPV vaccine.
HPV infection is primarily transmitted by genital contact, usually through sexual intercourse. It appears that the more sexual partners a woman or girl is exposed to, the higher the rates of HPV infection. Unfortunately, a partner’s sexual behaviors and multiple partners increase the risk of HPV infection for girls and women as well.
Because HPV is transmitted by sexual activity, understanding the epidemiology of HPV requires data on sexual behaviors. The 2002 National Survey of Family Growth (www.cdc.gov/nchs/nsfg) indicates that 20 percent of females in the U.S. were sexually active by age 15. The percentage increased to 40 percent by age 16 and to 70 percent by age 18. Among sexually active females aged 15-19 and those aged 20-24, the median number of lifetime male sex partners was 1.4 and 2.8 respectively. In addition, the 2005 Youth Behaviors Survey indicated that 3.7 percent of female students had been sexually active before age 13. Further it is reported that 5.7 percent of ninth grade and 20.2 percent of 12th grade females had four or more sex partners. Another study of college-age women revealed that the probability of the incidence of HPV was 38 percent by 24 months after first sexual intercourse.
HPV is not the cause of all cervical cancers. Approximately three-fourths of all cervical cancers in the U.S. are found to be squamous cell cancers. The remaining are HPV induced. Furthermore, reporting of HPV does not exist in the United States. Information on the prevalence and incidence is generally from clinic-based populations such as family planning and sexually transmitted disease among university health clinic patients. Detecting HPV infection is not a simple task; it requires identification through DNA testing approved by the U.S. Food and Drug Administration. The HC2 HPV DNA test uses liquid nucleic acid in serologic format.
The National Women’s Health Network (NWHN: March/April 2007) reports in a column by Adriane Fugh-Berman, M.D., that 10 percent of women with HPV stay infected. It is these women with persistent infections who are at the highest risk for HPV to progress to cervical cancer.
Cervical cancer rates in the U.S. have decreased because of the widespread use of Papanicolaou testing that can detect precancerous lesions before they develop into cancer. However, during 2007 an estimated 11,100 new cases were diagnosed and it is estimated that from this, 3,700 will die from cervical cancer. Fugh-Berman notes that the need for Pap smears is still necessary because there are other organisms that cause cervical cancer other than those caused by the HPV virus.
Worldwide, the rate of cervical cancer accounts for the second most common cancer cause of death in women, accounting for 288,000 cervical cancer deaths annually according to Fugh-Berman. The development of the cervical cancer vaccine, to protect against the HPV virus, is a public health breakthrough with the potential to save many lives worldwide.
It is important to note that the vaccine, Gardasil, only works well if it is administered before a woman, or girl, is exposed to HPV. The politics of immunization are interesting. Although some states have made it mandatory for all girls, nine years and over, to be vaccinated, the outcry and opposition from other states has been significant. Many do not want the vaccination to be mandatory. As a result, Merck has curtailed its efforts to lobby state legislatures to require the vaccination of all school girls, according to Fugh-Berman. In spite of this, bills are being introduced or drafted by legislatures in 20 states. However, the public backlash against this mandatory vaccination has been severe. There should be an outcry, she says, but not because of vaccine safety. It is safe and well tested, but it should not be orchestrated by a corporation. Rather, Fugh Berman says that public health policy that prevents the possibility of cervical cancer should be the main reason for the vaccine. The policy should be presented by health care professionals not those who will turn a profit. In addition, she says that there should be public education about the use of condoms and cervical cancer screening, and cervical vaccines.
In the end, the choice is up to you and your family. It is true that there are other mandatory vaccines required for entrance into kindergarten. We as parents are conditioned to these immunizations. The argument for HPV vaccine is still under consideration in Utah and many other states. It makes sense to prevent cancer. But this issue also contains a sexual component. Many parents and others in the community are in denial that our young women, like it or not, are engaged in sexual activities at an earlier age than in previous generations. The decision, as it should be, is up to you.