The International Agency for Research on Cancer (IARC) classifies viruses according to their oncogenic potential as "carcinogenic" (high risk), "probably carcinogenic" (intermediate risk), and "possibly carcinogenic" (low risk).

Papillomaviruses have a numerical classification as they have been discovered, so we now know more than 100 viral types, of which 40 have been found in the genitals, 15 of them with possibilities to produce some type of lesion in the sexual organs.

Viral types are discriminated according to the affinity of their genetic material.


When there is more than 10% difference between one HPV and another it is considered to be a new type of papilloma virus. Therefore, since its discovery the number of known papillomavirus has increased.

High-risk HPV: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56 and 58. Of these types, HPV 16 and 18 are considered the most important, Associated with cervical cancer.

Persistent high-risk HPV infection (which does not go away for years) increases the risk of cancer in people, since infection with this type of virus causes cellular changes that over time can lead to cancer, if not are treated.

HPV INTERMEDIATE RISK: 26, 53, 66, 68, 73, 82. It is not clear whether the risk of causing some form of malignant change in the cell is high or low.

Low risk HPV: 6, 11, 40, 42, 53, 54 and 57. In this group are those with no potential to cause cancer, but capable of provoking genital warts or condylomata acuminata (fleshy formations such as cauliflowers appearing on mucous membranes Of the genitals). This group of HPV can cause mild changes in the cervix of a woman, but these changes do not lead to cancer. Usually, they are not harmful and disappear over time.

Papilloma viruses are divided, for their ability to transform a cell into cancer, in:

     - High risk

     - Intermediate risk

     - Low risk

Papilloma viruses are also classified by numerical order, so we now know more than 100 different viral types.

All tissues are susceptible to infection, but there is a greater prevalence of a particular virus per given tissue.