Human papilloma-virus (HPV) is a virus that causes infections of the skin and mucous membranes.
The walls of body surfaces that come into contact with the outside of the body.
It is usually spread from person to person through skin-to-skin contact, including sexual contact.
1. HPV description
There are more than 100 types of HPV, all of which can affect different parts of the body… and about 40 of these are transmitted through sexual contact.
Some types of HPV can cause warts (such as genital warts or plantar warts), and others can cause cancer, such as cervical or anal cancer.
At least 70% of men and women who have sex will have an HPV infection at least once in their lifetime.
The different types of HPV are classified as low or high risk depending on their degree of association with cancer.
The "low risk" types rarely cause cancer. High risk" types are associated with a greater likelihood of developing cancer, but they do not necessarily lead to cancer.
These different types of HPV can cause a variety of conditions, including :
Skin warts - also known as vulgar warts, plantar warts or flat warts. They are caused by low-risk virus types.
Warts can appear on your arms, face, feet, hands and legs at any age, but most commonly during childhood;
Genital warts - HPV types 6 and 11 cause about 90% of genital warts, both of which are low risk;
Cervical dysplasia - HPV can cause lesions in the form of abnormal cells in the cervix - this is called cervical dysplasia.
These lesions are considered precancerous (they are not cancer cells, but they may eventually turn into cancer cells).
HPV infection frequently clears up on its own, but cervical dysplasia must be treated because it can lead to cervical cancer;
Cervical cancer - HPV types 16 and 18 are high-risk viruses and cause about 70% of cervical cancers.
HPV types 31, 33, 45, 52 and 58 are other high-risk HPV types and cause about 20% of cervical cancers.
These HPV types have also been linked to the development of penile and anal cancers.
HPV can cause infections and lesions elsewhere in the body, such as in the upper respiratory tract.
The majority of HPV infections are usually harmless, although they can be embarrassing.
However, since HPV infections can lead to cervical cancer, and other types of cancers, are cause for concern.
2. Causes
HPV enters the body, usually through a lesion in the skin, and then infects the cells that make up the different layers of the skin.
It can take weeks, months or even years from the time of infection with HPV to the appearance of lesions.
Many people may not even know they are infected with HPV.
HPV is usually transmitted through skin contact. HPV infections that cause skin warts can be acquired through a cut.
Walking barefoot in public areas such as a gym or swimming pool can be a risk factor for infection with the types of HPV that cause warts.
HPV infections that cause genital warts are highly contagious and are usually contracted during sexual activity with an infected person.
This could be from kissing or touching the skin of an infected area (e.g. scrotum, vagina, vulva, anus) as well as through sexual intercourse.
Although the likelihood of transmitting HPV is greater when lesions or warts are visible, transmission is possible even when there are no visible warts.
A mother with an HPV infection can also pass the virus to her baby during childbirth.
Risk factors for HPV infection include:
Age - children and young adults are at greater risk of getting vulgar warts and flat warts.
Genital warts usually occur in adolescents and young adults;
Number of sexual partners - the more sexual partners a person has, the higher their risk of having genital HPV infection;
The immune system – Immuno-compromised people (e.g., those with HIV-AIDS, organ transplant recipients., or people taking immunosuppressive drugs) have risk factors that make them more susceptible to genital HPV infection.
3. Symptoms and Complications
A person can contract the virus at some point and the germ can remain in the body for weeks., years and even the rest of their life without showing symptoms of infection.
The symptoms that will occur will vary depending on the type of infection that HPV triggers:
Vulgar warts are firm, painless growths with a rough surface. They appear on the knees, face, fingers and around the nails;
Flat warts are small, smooth warts that appear in clusters on the back of the hand, face or legs;
They can be painful because they are located on a part of the foot that carries the weight of the body;
Thread-like warts protrude around the eyes, face and neck;
Genital warts are small flat or cauliflower-shaped lesions. They are found on genital areas, including the vagina, cervix, vulva, penis, scrotum and anus.
They are usually painless, but they can bleed or cause itching or discharge;
Precancerous lesions or cervical dysplasia are abnormal cells in the cervix.
They are painless and can only be detected by a Pap smear (the Papanicolaou test).
HPV can also cause cervical cancer, cancers of other genital areas, and cancer of the head, neck and throat.
4. Diagnosis
Your doctor will diagnose skin warts or genital warts based on a physical examination.
Under certain circumstances, your doctor may perform a biopsy (removal of a small sample of tissue)… to accurately diagnose genital warts and rule out other conditions that may also be causing the symptoms.
To diagnose and test for precancerous lesions, your doctor will perform a Pap smear.
This test can detect abnormal cervical lesions, so it is important that women have it done at the prescribed intervals., even if they have received the HPV vaccine.
HPV DNA testing is available in Canada, but only in a small number of regions.
HPV DNA testing is not part of regular check-ups or Pap smears.
When recommended and used in certain situations, the results of HPV DNA testing and Pap smears are used to determine a woman's risk of cervical cancer.
5. Treatment and Prevention
There is no effective treatment for HPV infections. However, most infections are cleared from the body by the immune system without treatment.
There are several treatment options for warts. Some treatments can be done at home while others must be done in the doctor's office.
Removing warts does not always eliminate the HPV infection. It is important to remember that warts may reappear after treatment since the virus may remain in the body.
Skin warts can be removed using over-the-counter treatments such as salicylic acid to remove layers of infected skin.
The doctor may also use cryotherapy (liquid nitrogen) to remove the wart by freezing it.
Genital warts can be treated with medications (e.g. imiquimod*, podophyllotoxin, podophyllum resin, trichloroacetic acid) or by physically removing the warts… (e.g. cryotherapy, electrosurgical extraction, laser treatment, surgical removal).
Depending on the circumstances and the time of diagnosis, abnormal cells of cervical dysplasia may be surgically removed.
To reduce the risk of genital warts, use a condom regularly. A condom can reduce the risk of HPV infection, but it is not a 100% guaranteed protection.
A condom can also provide protection against other STIs (e.g. Chlamydia, herpes, HIV).
Reducing the number of sexual partners can also help reduce the risk of HPV infection.
To reduce the risk of skin warts, such as vulgar warts or plantar warts, avoid walking barefoot in public places.
Always wear sandals or shoes. This will also reduce the risk of passing the infection on to others or spreading it to other parts of your body.
