Human papillomaviruses, also called HPVs, make up a group of over a hundred related viruses that infect people.
Most HPVs can cause common skin warts, usually on the hands or feet.
However, about forty types of HPV infect the genitals, which are the sex organs on the outside of the body.
These HPVs cause the most common sexually transmitted infections, illnesses transmitted from one person to another
through sexual activity.
Some genital HPVs are low-risk, and may only cause warts on and around the genitals and anus of both women and men.
Rarely, these HPVs can also cause warts inside the mouth and throat.
Other genital HPVs are high-risk. They can lead to cancer of the lower end of a woman's uterus, called the cervix.
Less commonly, these HPVs can lead to other genital, anal, or oral cancers in both women and men.
It's important to know that most HPV infections cause no symptoms.
And, the low-risk genital HPVs that cause warts are not an important cause of cancer.
People infected with either a high-risk or a low-risk genital HPV spread it through skin-to-skin contact
during vaginal, anal, or oral sex.
For infection to occur, HPV enters through tiny cuts in the skin around or inside the penis, vagina, throat or anus.
The virus makes its way down to the cells in the bottom, or basal, layer of skin,
and infects them.
As the infected cells divide, the virus begins to make copies of itself.
Eventually, the infected cells move up through the skin layers, releasing new viruses that can spread the infection to other cells.
For most people, the cells of the immune system can destroy the infected cells, along with the virus, within two years.
But, in some people, the immune system isn't able to destroy all of the viruses,
leading to an infection that doesn't go away.
HPV-infected cells may multiply over several weeks or months.
If the cells are infected with low-risk HPV, they begin to form warts around the genitals.
If the HPV is high-risk, it may damage the cells' genetic material, causing the cells to become pre-cancerous.
Over a period of years, a cancerous tumor may slowly form as the damaged cells continue to multiply.
The most common cancer from high-risk genital HPV is cervical cancer.
There is no cure for any type of HPV infection.
However, the Gardasil vaccine can help protect against two of the most common high-risk HPVs that cause genital cancers.
The vaccine also helps protect against two of the most common low-risk HPVs that cause genital warts.
For best protection, preteen girls and boys should receive three doses of the vaccine over a period of
six months before any sexual activity takes place.
The vaccine injects dead proteins from HPV viruses into the bloodstream. These proteins don't cause infection.
But, the proteins do stimulate certain immune cells to create markers, called antibodies, that can identify these HPVs.
Later, if the live versions of these viruses invade the skin, the antibodies recognize and attach to them.
These immune cells destroy the marked viruses, which prevents an infection from happening.
It is important to note that the vaccine does not protect against other types of HPV not included in the vaccine.
The vaccine also doesn't reliably treat cells that are already infected.
High-risk genital HPVs that cause cervical cancer are most treatable when diagnosed early.
Women should have a Pap test to see if their cervix has abnormal or pre-cancerous cells,
even if they've had an HPV vaccine.
Check with a healthcare provider to find out how often to get this test.
During this procedure, a healthcare provider will collect a small sample of cells from the cervix.
These cells will be examined under a microscope to see if they're abnormal or cancerous.
A separate HPV test will look for genetic material from high-risk types of HPV.
When a Pap test and HPV test are done together, it's called co-testing.
If these tests show abnormal cells, a healthcare provider will recommend specific treatment based on the woman's age,
medical history, and the abnormality of her cells.
While there is no cure for an HPV infection, both abnormal and cancerous cells can be treated.
Some types of HPV can cause common skin warts or genital warts.
The warts may go away without treatment as the immune system fights off the HPV infection.
If the warts are painful or don't go away, visit a healthcare provider so they can examine the warts to
determine the best way to remove them.
Although you can treat common warts at home, do not treat genital warts yourself.
Procedures to remove either common warts or genital warts include:
freezing with cryotherapy, burning with an electric current, called electrocautery,
or by surgical removal.
For more information, talk to a health care profesional.