R.L.
Hi J.,
There are over 100 HPV types, but only 14 types are considered high risk -- that is, associated with, and probably causal, of cervical, penile, and anal cancers. These types have also been found to be associated with certain types of lung and throat cancers, as well. The 14 types of concern are: HPV-16, HPV-18, HPV-31, HPV-33, HPV-35, HPV-39, HPV-45, HPV-51, HPV-52, HPV-56, HPV-58, HPV-59, HPV-68, HPV-69.
There are also several low-risk types that cause genital warts. These are: HPV-6, HPV-11, HPV-40, HPV-42, HPV-43, HPV-44, HPV-54, HPV-61, HPV-72, HPV-81.
Specific antibody testing can only tell if some kind of HPV is present (this testing is standard as part of one's annual exam). The different types can only be determined by taking samples of dysplastic tissue (generally by Papp smear) and using very sensitive molecular tests to "read" the viral DNA (genome). This can be very costly, so the test may not be done unless it is specifically requested by the patient or doctor. Often, doctors will take a "wait and see" approach, taking cervical samples 4 - 6 months apart, looking for changes in levels of dysplasia and cancerous cells. There are a couple of tests that I'm aware of on the market right now: HPVDetx offered by Esoterix, Inc. (test is performed by their lab, I think) and Roche's method using Amplicor (large labs like Quest probably offer this one).
Even if you are found to have a high-risk variant, this doesn't mean that you will develop cancer. 90% of the people infected with a high-risk type of HPV will clear the virus on their own, although the virus may not actually be fully cleared, but simply be dormant. Dormancy means that the virus is not actively replicating (reproducing itself within your cells), so there's not enough of it being shed to detect it. BUT, current thinking is that, like with HBV and HCV, the virus only has the potential for causing cancer if it is a chronic, nonresolving infection and is actively replicating.
BTW, there are several articles in the medical literature that suggests that HPV can be passed nonsexually. In a 1999 paper by Sonnex et al, they isolated low-risk HPV from the finger tips and under the finger nails of patients with active genital warts. The virus is shed by infected genital skin, which is how it is transmitted sexually (skin-to-skin contact is necessary, in fact). So if you shake hands with someone who has an active infection and has less than perfect hygienic habits, there is actually the possibility of contracting the virus from them. (I will leave the details to your imagination.) Also, pulmonary (lung) pappillomas may be caused by inhaled HPV. High-risk HPV can also be transmitted vertically, that is, from mother to fetus in the womb, or more likely, as with HSV (genital herpes), from mother to newborn during passage through the birth canal. It may be this transmission that is responsible for HPV-associated lung pappilloma in children.
One bright spot on the horizon for our daughters (and our sons, by extension!) has been the development of Gardasil, a vaccine that protects against 2 of the most common types of low-risk HPV (6 and 11) and 2 of the most common types of high-risk HPV (16 and 18). The vaccine is only effective if it is given before infection, which is why it is recommended for girls age 9 and over. I got my daughter vaccinated less than a month after the vaccine became available (she was 12 at the time). As a person who specializes in infectious disease, the RELIABLE body of research clearly shows that there are far fewer and less severe risks associated with immunizations as they're manufactured and given today, than there are from the dangers of many of the diseases if you were to actually contract them.
Before any of the vaccines-and-the-pharma-companies-that-produce-them-are-evil-greedy-b***ds-and-are-bad brigade want to try to "educate" me about this, you need to understand that this is about RELATIVE risks. Yes, some children (and adults) can have adverse reactions to vaccines and these can be severe, and even fatal. But the relative risks of this happening are very, very, small compared to the relative risk of equal or worse outcomes from contracting most of the diseases we currently have vaccinations for. That's why scientists and doctors have worked for so long to develop vaccines. The diseases they have focused on can be killers or have substantial impact on quality of life for the long term (OK, I DO have some reservations about the necessity of the chicken pox vaccine). The fact that we don't see the high death rate from diseases such as tetanus, polio, measles, and Rubella any more is because we have had such successful vaccination programs in this country for the last 50 years. It is NOT because these diseases have mysteriously weakened or died out on their own. If you want to argue with me on this one, I will entertain your thoughts after you've completed 5 or 6 years of graduate school in immunology or epidemiology. (Sorry for the diatribe, J.! It's not directed at you.)