Human Papillomavirus

What is human papillomavirus (HPV)?

Human papillomavirus (HPV) is a virus that affects different parts of the body. There are many different strains of HPV, and it is a common virus that can cause warts.

Many strains of HPV (around 30) can affect the genitals, including the vagina, cervix, rectum, anus, penis, and scrotum. Others strains of HPV can affect the face, hands and feet.

The strains of HPV that can cause genital warts are passed from person to person via physical contact. Most cases of HPV that cause genital warts are harmless.

Only certain strains of HPV can cause cervical cancer. These are considered high-risk and if detected, affected women will be screened more frequently and/or a diagnostic test called a colposcopy will be performed.

Warts and HPV

While all warts are caused by strains of HPV, not all strains of HPV cause warts. HPV that causes genital warts are called type 6 and type 11. Other strains of HPV can cause:

• Common warts
• Flat warts
• Periungal and subungual warts
• Plantar warts.

Does HPV cause cervical cancer?

Cells within the cervix can be transformed by certain strains of HPV, most commonly types 16 and 18. This transformation leads to the development of pre-malignant cells called dysplasia. In younger women (under 30), the immune system often suppresses an HPV infection. If it doesn’t, over time and if left untreated, these changes can sometimes progress to cervical cancer.

Women who have previously had an abnormal smear, or who have tested positive for an HPV infection, will receive more regular Pap smears. Regular Pap smears are important to screen for cervical cancer. However, just because you have HPV or cervical dysplasia, it doesn’t mean you’ll get cancer.

Who is affected by HPV?

Anyone who has had skin to skin contact with someone with the HPV virus can become infected. Most individuals who contract HPV are asymptomatic.

Routine Pap smears can detect cell changes that are precancerous and can prevent cervical cancer. Other strains of HPV (not associated with cervical cancer) can cause harmless warts in both women and men.

In men, HPV infections can lead to cancer in the anus, penis, head and neck, however, these are rare.

What are the symptoms of HPV?

HPV strains that affect the genitals don’t usually cause symptoms. If they do, the signs of the virus are usually rough lumps on the skin of the genital area. These warts can appear weeks or months after infection. They are harmless but contagious.

Forms of HPV that can progress to cancer don’t cause symptoms until cancer is present. Cervical cancer is the most common HPV-related cancer, it can also lead to anal, penile, throat, vaginal and vulvar cancer, but these are much rarer.

How is HPV diagnosed?

Genital warts are usually diagnosed via a physical examination. The strains of HPV that can progress to cancer don’t cause symptoms, so they are diagnosed following an HPV test.

A Pap smear looks at a sample of cells taken from the cervix, screening for abnormalities in the form of precancerous cells (cervical dysplasia).

An HPV test also takes a sample from the cervix, to detect high-risk HPV strains that may cause cervical cancer.

If a Pap smear shows changes in cervical cells, you have tested positive for HPV, or a doctor suspects abnormal cells that are caused by an HPV infection, other diagnostic tests may be performed. These include:

Colposcopy: A lighted tool which magnifies the cervix, called a colposcope, is used to look for abnormal cells. A sample of tissues may be removed via a biopsy, which will look for signs of precancer or cancer.

How is HPV treated?

Treatment cannot rid the body of the HPV virus. There is no cure for the virus, but in most cases (around 90%), your immune system will suppress the virus within a couple of years.

Treatments can remove visible warts from the body and cervical dysplasia. These include:

• Cone biopsy (conization): A cone-shaped piece of tissue is removed from the cervix which contains the abnormal cells.
• Cryosurgery: Warts or abnormal cells are frozen and destroyed with liquid nitrogen.
• Electrocautery: Warts are burnt off with an electrical current.
• Laser therapy: An intense light is used to destroy warts or abnormal cells.
• Loop electrosurgical excision procedure (LEEP): A heated wire loop is used to remove warts or abnormal cells on the cervix.
• Prescription cream: Creams can be applied directly to warts to destroy them.
• Trichloroacetic acid (TCA): A chemical treatment that is used to burn off warts.

HPV vaccination

A vaccine is now available which can protect against nine of the strains of HPV that cause genital warts and cervical cancer.

Only a small number of people who are infected with high-risk HPV will go on to develop abnormal cells within the cervix that require treatment. The most effective way to protect yourself from abnormal changes and cervical cancer is through regular Pap smears and HPV testing starting at age 25.