Human papillomavirus (HPV) is one of the most common causes of sexually transmitted infection (STI) in the world. Health experts estimate that there are more cases of genital HPV infection than of any other STI in the United States. According to the American Social Health Association, approximately 5.5 million new cases of sexually transmitted HPV infections are reported every year. At least 20 million Americans are already infected.
Scientists have identified more than 100 types of HPV, most of which are harmless. About 30 types are spread through sexual contact. Some types of HPV that cause genital infections can also cause cervical cancer and other genital cancers.
Like many STIs, genital HPV infections often do not have visible signs and symptoms. One study sponsored by the National Institute of Allergy and Infectious Diseases (NIAID) reported that almost half of the women infected with HPV had no obvious symptoms. People who are infected but who have no symptoms may not know they can transmit HPV to others or that they can develop complications from the virus.
What are genital warts?
Genital warts (condylomata acuminata or venereal warts) are the most easily recognized sign of genital HPV infection. Many people, however, have a genital HPV infection without genital warts.