The human papillomavirus (HPV) causes genital warts. More than 100 types of HPV have been identified. Types 6 and 11 cause the most visible genital warts.

How the disease is spread (transmission)

HPV is spread by direct contact.

• The virus can be spread to or from the genitals, anus, mouth, or throat during sexual activities. However, warts in the mouth or throat are extremely rare. Condoms can lower your risk of getting genital warts. You can prevent infection when you use them every time you have sex.
• After the infection occurs, it may spread to other areas of the genitals or to the anal area.
• You can spread the virus even if you do not have any symptoms of infection or any visible warts.
• A pregnant woman can infect her child during vaginal delivery, although this is very rare. An infection rarely causes growths on the baby's larynx (laryngeal papillomas), which is in the throat. The presence of genital warts does not mean that the mother should have a cesarean delivery, unless a vaginal delivery would cause the warts to bleed excessively.¹