10 Percent of Women Infected with Human Papillomavirus by Age 16
A new study by the Health protection Agency estimates at least 10% of young women in England have been infected with one or more strains of the human papillomavirus (HPV) by the age of 16. The study will be discussed on the last day of the Health Protection Agency annual conference in Warwick.
The study, the first of its kind in England , investigated the proportion of women aged 10-29 years who had antibodies indicating they had been infected with HPV. Researchers tested blood samples from 1483 girls and women for types of HPV that can cause genital warts and cervical cancer. Results show that from the age of 14, the risk of HPV infection increases sharply.
Some HPV infections can cause cervical cancers in women and genital warts in both women and men, although most infections with HPV cause no symptoms and clear on their own.
Andrew Vyse, who is presenting the study to the conference said: “This study gives us vital information about how common HPV infection is in young women of different ages. However it does have some limitations and does not give a precise estimate of infection rates in young women in England therefore more work needs to be done.
“The study adds to what we already know about HPV, however we still need to learn more about the risks of infection and of the risks for persistent infection and progression to cancer.
Professor Pat Troop , Chief Executive of the Agency said: “This study is a valuable addition to our understanding of HPV infection in women in England and should contribute to effective policies to prevent genital warts and cervical cancer.
“With the Government’s recent announcement of the possible introduction of HPV vaccination, such research will help us and other public health experts to determine the impact of HPV vaccination.”
Basic facts on HPV
HPV (human papillomavirus) is the common wart virus. It is the cause of the various kinds of warts (genital warts, plantar warts, flat warts) as well as cervical dysplasia, vaginal dysplasia, and cervical cancer. HPV has been implicated as a cause of infertility, miscarriages, vaginosis, vaginitis, vulvar vestibulitis syndrome, prostate disease, and laryngeal papillomatosis.
Common misspellings for human papilloma virus include human papillomavirus, human papilloma virus, human papiloma virus, human papaloma virus, human papalloma virus, human pipiloma virus, human pipilloma virus, and many more.
It is impossible to determine how long someone has had an HPV infection. Neither men nor women are routinely tested for HPV. Women are “indirectly” tested for HPV by a Pap smear which shows “HPV characteristics” if the HPV has damaged some cells resulting in cervical dysplasia. If the cells are not damaged, the HPV goes undetected unless a Digene Hybrid Capture® HPV DNA Test is done.
Other test methods (specific blood tests) may show that there has been HPV infection in the past, but they cannot determine if HPV is currently present. HPV is usually diagnosed because the cervical or vaginal cells obtained by Pap smear or biopsy have the “characteristic appearance of HPV-infected cells” under the microscope.
HPV is not always transmitted sexually. However, the types that cause anogenital warts (also called condylomata acuminata, venereal warts, genital warts, vaginal warts, and penile warts) and cervical dysplasia are most commonly sexually transmitted, like low risk HPV types 6, 11, 42, 43, and 44. For this reason HPV is classified as an STD (sexually transmitted disease) and can be transmitted through sexual intercourse, oral sex, anal sex, or any skin-to-skin contact.
Some women develop genital warts, cervical/vaginal dysplasia, or both, while others become carriers with no signs or symptoms, or they become immune to certain HPV types. Men generally develop genital warts, become carriers, or develop immunity.
HPV is contagious even when warts and dysplasia are not present. Some HPV types have a greater association than others with cervical dysplasia and cancer like high risk HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68. All of the HPV types are contagious.
HPV can lie dormant in humans for an unknown period of years. However, most individuals develop immunity, after which time they are no longer contagious.
It is impossible to prove that someone does NOT have any HPV types. It is relatively easy to prove when someone DOES have HPV, if (1) signs or symptoms are present, or (2) the Digene Hybrid Capture® HPV DNA Test is positive.
Some feel that HPV remains in a carrier state for years; however, this is probably uncommon. There are over 70 types of HPV. This may be the reason some believe that long carrier states are common. What may be viewed as a carrier state may simply be subsequent infections by different HPV types over the years. There are over 300 rhinoviruses (cold viruses), yet no one considers a cold virus to be in a perpetual carrier state that “flares up” periodically.
There is very little cross-immunity between the different HPV types. This means that if one has immunity to one HPV type, that specific immunity is not necessarily good against another HPV type.