HPV, or Human Papilloma Virus, is the name of a group of viruses comprising more than 100 different types. About 1/3 of the types are sexually transmitted causing genital infections. The other types are responsible for common warts affecting skin on other parts of the body such as the hands or feet. While most HPV infections have no long term consequences, a few "high risk" types can cause cancer.
Genital HPV is transmitted through skin-to-skin contact rather than bodily fluids. This makes it harder to defend against it with usual safer sex practices such as condoms and dental dams. It is the most common STI (Sexually Transmitted Infection) comprising 1/3 of all new infections. About 75% of Americans between 15 and 49 have been infected with genital HPV. Because it is so prevalent a person doesn't need to have a lot of sex partners to be exposed to one of the types of HPV. It is possible to transmit the virus using fingers for stimulation and probably with the use of sex toys.
HPV can be clinical (with symptoms) or subclinical (without symptoms). Many people never realize they are/were infected. The virus can be transmitted by someone who has no symptoms. Genital warts are the visible, clinical version of HPV. Genital warts appear as flesh-colored bumps or collections of bumps in the genital area. They can be raised or fairly flat, rough or relatively smooth involving the vulva, in or around the vagina or anus, on the penis, scrotum, or groin area. 90% of the genital warts are caused by "low risk" types that do not cause cancer. Most of the high risk types cause no symptoms, but can lead to cervical cancer and less commonly anal, penile and head and neck cancers.
The best way to detect subclinical infection is to have regular pap smears. A pap smear is done by taking a sample of cervical cells which is examined for abnormal or precancerous changes by a pathologist. Go to the Pap Smear page for more information. Some experts recommend screening with anal pap smears for gay and bisexual men.
There is currently no good screening test for men, but their risk of developing any kind of abnormal cells is small. If visible warts are present it is a good idea to see a medical provider.
As with all viruses there is no specific cure for the virus itself. However, most HPV infections are transient, being cleared from the body by the immune system within months to two to five years, and with no long term harm. If HPV persists past the age of 30 it is more likely that the immune system will fail to clear the infection and the chance of abnormal cellular changes increases. Some women over 30 will get specific HPV screening along with their pap smears.
Since there is no specific treatment for the virus itself, therapy is aimed at increasing the immune system response to the virus and decreasing the amount of virus present to prevent transmission to sexual partners. For clinical, or visible genital warts the goal of treatment is to eliminate discomfort and to possible decrease the risk of transmission. For subclinical infection treatment may not be necessary because the cells can heal on their own. Although the majority of women with genital HPV will not develop cervical cancer, certain strains are more likely to cause cervical changes which may over time develop into cancer. Cervical cancer usually takes several years to develop. For some cervical changes the only treatment needed is to monitor with more frequent pap smears. More active treatment is done based on the size of lesions, severity of changes, age of the person and personal preferences. Other factors including smoking and the presence of other STIs affect whether cancer develops.
Cervical cancer is completely preventable.
Once a person is exposed to a type or strain of virus they develop immunity to that type and are unlikely to get re-infected with the same type. Partners who are sexually intimate only with each other will not pass the virus back and forth.