What is human papillomavirus (HPV) ?
Human papillomavirus (HPV) is a virus that can be passed from person to person through skin-to-skin contact. More than 100 types of HPV have been found. About 30 of these types infect the genital areas of men and women.
How is HPV spread?
HPV is primarily spread through vaginal, anal or oral sex but sex intercourse is not required for infection to occur. HPV is spread by skin-to-skin contact. Sexual contact with an infected partner, regardless of the sex of the partner, is the most common way the virus is spread.
What disease does HPV Cause?
Approximately 12 types of HPV cause genital warts. Two types, type 6 and type 11, cause most cases of genital warts. Genital warts are growths that may appear on the outside or inside vagina or on the penis and can spread to nearby skin. They also can grow around the anus, on the vulva, or on the cervix. They can be treated with medication that is applied to the area or by surgical removal. The type of treatment depends on where the warts are located.
About 15 types of HPV cause cancer of the cervix. They also cause cancer of the vulva, vagina, anus, penis, and the head and neck. Most cases of cervical cancer are caused by just two types of HPV-Type 16 and type 18.
How does HPV cause cancer of the cervix?
The cervix is covered by a thin layer of tissue made up of cells. If one of the cancer-causing types of HPV is present, it may enter these cells. Infected cells may become abnormal or damaged and begin to grow differently. It usually takes several years for cervical cancer to develop. Cervical cancer screening can detect early signs of abnormal changes of the cervix and allows early treatment so that they do not become cancer.
How effective are the vaccines in preventing HPV infection?
The four type vaccine is almost 100% effective in preventing cervical precancer and genital warts caused by four types of HPV. The two type vaccine is almost 100% effective in preventing cervical precancer caused by two types of HPV.
The vaccines are most effective if they are given before a women is sexually active and exposed to HPV. If a women is already infected with one type of HPV, the vaccines will not protech against disease caused by that type. However the vaccines can protect against the other types of HPV included in the vaccines.