Human papillomaviruses (HPV) are DNA viruses that are sexually transmitted and replicated in cells. There are over 120 types of HPV, which differ in the types of tissue they infect. More than 40 types affect the anal and genital epithelium (cervix, vagina, vulva, rectum, urethra, anus, penis) and some of these are defined HPV high-risk are those related to the emergence of various types of tumors, especially of the cervix, but also the penis, anus, vulva, and others.
Of high-risk HPV, HPV 16 and the 18 are those most frequently implicated in cervical cancer, being responsible respectively for about 60% and 10% of all cervical cancers. Other high-risk types are associated with cervical cancer, but less frequently, while low risk HPV (those not linked to cancers) can still cause anogenital warts in both sexes.
Most HPV infections are transient, because the virus is eliminated by the immune system before developing a pathogenic effect. In case of persistent infection, the time between infection and the occurrence of precancerous lesions is about five years, while the latency for the onset of cervical cancer can be 20-30 years. (more…)