HPV infections have no signs or symptoms The human papillomavirus (HPV) is the name of a group of viruses that includes more than 100 different strains or types, according to the Centers for Disease Control and Prevention's Internet Web site on sexually transmitted diseases. More than 30 of these viruses are transmitted sexually and they can infect the genital area of men and women. Most people who become infected with HPV will not have any symptoms and will clear the infection on their own. Most HPV infections have no signs or symptoms; therefore most infected persons are unaware they are infected but they can still transmit the virus to a sex partner. Some of these viruses are called "high risk" types and may cause abnormal PAP tests. They may also lead to cancer of the cervix, vulva, vagina, anus or penis. For 2004, the American Cancer Society estimated that about 10,520 women will develop invasive cervical cancer and about 3,900 women will die from this disease. A PAP test is the primary cancer screening tool for cervical cancer or precancerous changes in the cervix. HPV is usually diagnosed in women based on results of an abnormal PAP smear. There are currently no HPV tests available for men. Other viruses are called "low risk" types and they may cause mild PAP test abnormalities or genital warts. Genital warts are diagnosed by visual inspection. Although there is no cure for HPV, there are several treatments for genital warts. According to the the National Institute of Allergy and Infectious Disease's Internet Web site, genital warts are very contagious. In addition to transmitting the warts through sexual activity, they can also be transmitted through skin-to-skin contact with someone who is infected. About two-thirds of people who have sexual contact with a partner who has genital warts will develop warts, usually within three months of contact. Approximately 20 million people are currently infected with HPV. At least 50 percent of sexually active men and women acquire a genital HPV infection at some point in their lives, according to the CDC's Web site. By age 50, at least 80 percent of women will have acquired genital HPV infection. About 6.2 million Americans get a new genital HPV infection each year. HPV is one of the most common causes of sexually transmitted infections (STI) in the world, according to the National Institute of Allergy and Infectious Disease. Health experts estimate there are more cases of genital HPV infection than any other STI in the United States.