Human Papilloma Virus (HPV) Infection

What are HPVs?

HPVs are responsible for the most common sexually transmitted disease. More than 100 types of HPV have been identified, around 40 of which infect the genital area. HPVs are mainly transmitted through sexual contact, with or without penetration. They are so common that most women who are sexually active will have contact with them sometime during their life. Fortunately, there are no consequences in the great majority of cases, because our immune system is able to fight the infection and get rid of the virus. Infected women do not usually present any complications from this infection and remain asymptomatic. The virus can be completely eliminated or remain dormant for many years. It can sometimes reactivate a long time after having been contracted.

HPVs that infect the genital organs are divided into 2 categories: low-risk HPVs which are not associated with the development of cancer. Among these low-risk HPVs, 2 types (HPV-6 and HPV-11) are responsible for warts (condylomas) on the external genital organs. Condylomas are not precancerous lesions.

The other category of HPVs is called “high-risk” or “oncogenic” (cancer-causing), as they have been associated with the development of cancer of the cervix, and more rarely of the vulva, vagina and anus. There are around 15 oncogenic HPVs; types 16 and 18 have been studied the most. By themselves, they are responsible for 50% of severe precancers and 70% of cervical cancers.

How can you prevent HPV infection?

As HPVs are transmitted sexually, you might think that adopting safer sexual behaviour could prevent HPV infection and its accompanying complications. A lifelong, exclusively monogamous relationship (one partner only throughout your lifetime, who himself has never had any other partner) will prevent HPV infection. However, lifelong monogamy is not common in our culture. In addition, the decision is not ours alone and depends just as much on our partner. Regular use of a condom, which is very effective in preventing other STDs, is unfortunately not as effective in preventing HPV infection because the virus can be found on areas not protected by the condom.

HPV vaccines represent the only way to prevent infection by certain HPVs. Two vaccines have been developed and marketed. They prevent more than 90% of infections, condylomas, and the severe precancers caused by the types included in the vaccine. Gardasil, which protects against types 6, 11, 16 and 18, has been approved by Health Canada and prevents condylomas and precancers of the cervix and vulva. Cervarix (which is now being evaluated by Health Canada) has demonstrated its ability to prevent infection by HPV types 16 and 18 and also cervical precancer. Both vaccines also provide limited protection against types of HPV not directly targeted by the vaccine.

The use of the Gardasil vaccine has also been evaluated for use in boys and appears effective in preventing condylomas.

What are the consequences of HPV infection?

Most individuals infected get rid of the virus, without sequelae (after-effects) and do not even know that they have had the infection. Rarely, HPV infection can cause the following problems:


Condylomas are small, often rough-surfaced lumps on the genital organs. A doctor can diagnose them by a simple visual examination if their appearance is typical. If there is any doubt, the doctor can perform a biopsy (take a sample of the lesion) for analysis.

The treatment of genital warts can be carried out by the patient or the doctor. Various substances can be applied at home on external lesions 2 to 3 times a week, with good results. The doctor may use other forms of treatment (acid, cryotherapy, laser, etc.) to make the lesions disappear.

Condylomas are caused by low-risk viruses and do not progress to the stage of cancer.

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