What is human papilloma virus (HPV)?
Human papilloma virus (HPV) is a contagious virus that is spread by skin-to-skin contact. A virus is a non-living particle that infects living things so it can grow.
HPV can infect the outer layer of skin and the smooth, moist linings of the mouth, the rectum, the anus and genital areas of males and females.
There are over 100 different kinds of HPV. Many of these types cause the common warts that appear on hands and feet. Other types, usually HPV 6 and 11, cause genital warts. HPV 16 and 18 have been linked to cancer of the cervix.
For some people, HPV may go away without treatment. For many people, though, once you have an HPV infection, the virus stays in your body. This means it is possible to have and pass on HPV, even if you do not have genital warts.
What are genital warts?
Genital warts can appear in different forms, sometimes weeks, months or years after being infected with HPV. There can be one or many in the genital areas or around the anus. They can be flat or raised. When the warts are raised, they may look like cauliflower. The warts can be pink, brown or the same colour as your skin.
Genital warts can disappear or reappear over time.
HPV is passed on by contact with the virus
HPV is passed on by skin-to-skin contact.
In adults, genital HPV infections are usually passed on by having sex with an infected person. HPV is one of the most common sexually transmitted infections. It affects up to three-quarters (75%) of sexually active people over a lifetime. Using a condom during sexual intercourse can protect some areas of the skin from HPV infection.
When a child has HPV, it is not always clear how the virus was passed on. Because it spreads with skin-to-skin contact, the virus can be passed on in the following ways:
- A pregnant mother who has HPV can pass on the infection to her child through the bloodstream before birth or through the vaginal canal during birth. This is called perinatal transmission.
- Children with warts on their hands can transmit the virus to their genital area by touching the warts on their hands and then touching their own genitals. This is called autoinoculation.
- A caregiver with warts on their hands or genitals can transmit the virus by skin-skin contact with the hands or the genitals of the child. This is called heteroinoculation.
- HPV can be passed on from the skin of a person to the genital area of a child through sexual contact. This is considered sexual abuse.
- Rarely, HPV can be passed on by contact with inanimate objects or surfaces. If an adult who has common or genital warts uses a towel, and then a child uses that same towel, the virus can be transmitted to the child. This is called fomite transmission.
Diagnosing HPV and genital warts
A doctor takes special care in diagnosing HPV and genital warts in children. Any child with genital warts needs a complete medical examination, which includes the following:
- A doctor or nurse will do a physical examination and look at the child's anus and genital area.
- The doctor or nurse will ask the mother and father if they have ever had HPV infection or genital or common warts.
- The doctor or nurse will ask the mother if she has ever had an abnormal Pap test, which could indicate HPV infection.
- The doctor or nurse may ask the parents about any concerns they have for sexual abuse, and may look for signs of sexual abuse on the child.
Testing for HPV
There is no routine test for HPV. It is possible to test for HPV directly, but this is not usually recommended because HPV is so common. Testing to find out the type of HPV does not give any extra information about when or how the child was infected.
HPV may be tested for the presence of high-risk strains that may cause cancer.
Looking for cervical abnormalities
In women or girls who are past puberty, the doctor may use tests called a Pap smear and a colposcopy to look for signs of problems that could lead to cervical cancer. Areas with minor changes can be treated early on.
- To do a Pap smear, a doctor uses a small tool to collect cells from the cervix. The cells are inspected under a microscope.
- A colposcopy uses a special type of microscope to look for areas of the cervix and vagina that may show changes.
Treatment for genital warts
Once genital warts are diagnosed, the doctor and patient decide together which method of treatment is best. There are a number of options for treating genital warts. Some treatments work better than others. Some treatments have risks or side effects, including causing significant pain; these treatments will usually be avoided unless necessary. Which treatment is chosen will usually be based on the number, site, and size of the warts. It will also be based on what the patient prefers, the cost and the side effects.
Usually, genital warts are treated with gels or creams that are put on the warts. Gels and creams include the following:
- Imiquimod (Aldara), a cream that is put on the warts. The patient applies this cream.
- Podofilox, a gel or a cream that is put on the warts.
- Tricholoracetic acid (TCA) or bichloroacetic acid (BCA), which the doctor puts on the warts.
Less often, the warts may be treated with liquid nitrogen (cryotherapy) or surgery.
- Cryotherapy: This is when very cold liquid nitrogen is applied to the wart. This treatment is quick, but it can also be painful because the liquid nitrogen causes the skin to blister and scab. When the scab comes off, the wart will come with it. Sometimes this treatment can fail, and alternate or repeat treatments are needed.
- In rare cases, surgery (an operation) may be needed to remove the warts.
Genital warts may go away and come back
Without treatment, genital warts may go away by themselves, or they may last for years. Even if they have been treated, genital warts may come back in time.
There is a vaccine that protects against HPV
There is a vaccine on the market called Gardasil that is currently used to immunize school-age girls, age nine and older. The vaccine provides immunity to two strains of HPV that are linked to cervical cancer and two strains that are linked to genital warts. The vaccine is made up of small, non-infective particles of a virus that is like HPV. It is given through three vaccinations over a six-month period.
It is recommended to have the vaccine before beginning sexual activity. The vaccine has been shown to be effective at protecting against HPV types 6, 11, 16 and 18.
Genital warts and cancer
There are many types of HPV; the type of HPV that causes genital warts is considered low-risk for cancer. However, a person can be infected by more than one type of HPV. Other types of HPV are high-risk (types 16 and 18). These can lead to cancer of the cervix; less often, they can lead to cancer of the vagina, penis or scrotum. Currently, it is impossible to test warts for all described types of HPV.