Sexually transmitted infections

Human papillomavirus (HPV)

What is human papillomavirus?

Human papillomaviruses (HPVs) refer to a group of more than 100 types of viruses. These visuses are named papillomaviruses because certain types may cause warts, which themselves are non-cancerous tumors called papillomas. The HPVs that cause the common warts that grow on hands and feet differ from those that cause warts in the throat or genital area.

How is HPV spread?

Of the more than 100 types of human papilloma viruses, over 30 can be passed from one person to another through sexual contact. This makes HPV infection one of the most common sexually transmitted diseases (STIs). The majority of HPV infections come and go over the course of a few years. Others may persist for many years, with or without symptoms: in fact, about 75 percent of people infected with HPV have no symptoms at all. It is for this reason that doctors can't say for certain when infection occurred.

Doctors do know, however, that genital warts caused by HPV are easily spread during skin-to-skin sexual contact—that is, during oral, vaginal, or anal sex with someone who has HPV. More than 66 percent—or two thirds—of people who have sexual contact with an HPV-infected person will develop wards, most often within 3 months of contact.¹

The pathology of HPV

Cells have a normal life cycle during which they grow, divide, and eventually die. Cellular changes associated with cancer cause cells to grow and divide out of control.

So what does this mean in terms of HPV? Human papilloma viruses produce proteins known as E5, E6, and E7 which interfere with cell functions that normally prevent excessive growth. HPV E6 interferes with the human protein P53, a protein present in all people that acts to keep tumors from growing. Research is being used to develop ways to interrupt the process by which HPV infection can lead to the growth of abnormal and/or precancerous cells.²

Because they can cause cell abnormalities, some HPVs are associated with certain types of cancer: studies suggest that HPVs may play a role in cancers of the anus, vulva, vagina, and oropharynx (that part of the throat that includes the soft palate, the base of the tongue, and the tonsils) and that it is also a risk factor for penile cancer. HPVs are also now recognized as the major cause of cervical cancer.³

Are there different types of HPV?

There are two types of HPV-"low risk" and "high risk." Because they rarely develop into cancer, some types of HPVs are classed as "low-risk." Those HPVs more likely to lead to the development of abnormal cells, precancers and cancer are called "high-risk." Put another way, both low-risk and high-risk types of human papilloma viruses can lead to the growth of abnormal cells, but it is generally only high-risk types of HPV that lead to cancer.

What is the link between HPV and cervical cancer?

Transmitted sexually, high-risk HPVs include types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, 69 and perhaps also a few others. As opposed to the warts caused by HPV-6 and HPV-11, growths caused by the aforementioned high-risk types of HPV are usually flat and nearly invisible. The majority of high-risk HPV infections go away on their own and do not cause cancer. Nevertheless, infection with high-risk HPV increases the possibility that mild cell abnormalities will progress to more severe abnormalities or cervical cancer.⁴

In most women, the cells of the cervix return to normal once the body's immune system has successfully destroyed the HPV infection. Nevertheless, you should know that since nearly all cervical cancers are caused by HPV, any woman who has had sex or who is currently sexually active can develop cervical cancer. What's more, most women who have had sex have been infected with HPV at some time in their life. Women at highest risk for cervical cancer are those in whom infection with one of the high-risk HPVs persists for several years.

In most cases, HPV infection carries no symptoms: the only way to know if you are infected with HPV is to have a direct test for the virus. Furthermore, the only way to tell if a high-risk HPV infection has caused changes in the cells of your cervix is to have a Pap test. Because the signs of an HPV infection can appear weeks, months, or even years after your first contact with the virus, Women's Web recommends regular pelvic exams and Pap tests as the most effective means of screening for cervical cancer. An HPV test can be done in conjunction with these to determine whether you have contracted an HPV infection or genital warts.

How can I prevent HPV infection?⁵

The only way to prevent getting HPV is to avoid direct contact with the virus. HPV is passed from one person to another by skin-to-skin contact. If you or your sexual partner has warts in the genital or anal area that you can see, you should not have any sexual contact until the warts are treated. Some studies have shown that using male latex condoms may protect you from getting diseases linked to HPV, such as genital warts and cancer of the cervix.

Here are some guidelines to help you reduce your risk for HPV:

• The best way to prevent HPV and any STI is to practice abstinence (don't have sex). Delaying having sex for the first time is another way to reduce your chances of getting an STI. Studies show that the younger people are when having sex for the first time, the more likely it is that they will get an STI. The risk of getting an STI also becomes greater over time, as the number of a person's sex partners increases.
• Have a sexual relationship with one partner who doesn't have any STIs, where you are faithful to each other (meaning that you only have sex with each other and no one else).
• Practice "safer sex." This means protecting yourself with a condom EVERY time you have vaginal, anal, or oral sex.
  For vaginal sex, use a latex male condom or a female polyurethane condom. For anal sex, use a latex male condom. If needed, use only water based lubricants with male and female condoms. For oral sex, use a dental dam—a device used by dentists, made out of a rubbery material, that you place over the opening to the vagina before having oral sex. If you don't have a dental dam, you can cut an unlubricated male condom open and place it over the opening to the vagina.
  Even though it may be embarrassing, if you don't know how to use a male or female condom, talk to your health care provider. The biggest reason condoms don't work is because they are not used correctly.
• Be aware that condoms don't provide complete protection against STIs. But, they do decrease your chances of getting an STI. Know also that other methods of birth control, like birth control pills, shots, implants, or diaphragms don't protect you from STIs. If you use one of these methods, be sure to also use a condom every time you have sex.
• Limit your number of sexual partners. Your risk of getting HPV increases with the number of partners you have.
• Don't douche. Douching removes some of the normal bacteria in the vagina that protects you from infection. This can increase your risk for getting HPV.
• Learn how to talk with your partner about STIs and using condoms. It's up to you to make sure you are protected. See There's No Excuse Not To Use a Condom for tips for talking with your partner. You can also talk with your health care provider about this.
• When you are sexually active, especially if you have more than one partner, get regular exams for STIs from a health care provider. Tests for STIs can be done during an exam.
And, the earlier an STI is found, the easier it is to treat.
• Learn the common symptoms of HPV infection and other STIs. Seek medical help right away if you think you may have HPV or another STI.

How is HPV detected?

There is a test designed to detect high-risk types of HPV. Women 30 and older can request an HPV test be done at the same time as their Pap test. During a Pap test, your health care provider uses a brush, wooden spatula or cotton swap to gently scrape your cervix. The cell sample is then smeared onto a glass slide and sent to a laboratory for analysis. A cytotechnologist or pathologist examines the cell sample under a microscope to determine whether any of the cells are abnormal.

If the Pap test reveals questionable changes in cervical cells, your health care provider may do an HPV test to learn more about these cell abnormalities. The HPV tests checks directly for high-risk viruses that may be present—even before there are any conclusive visible changes to the cervical cells. What's more, the U.S. Food and Drug Administration (FDA) has approved an HPV test that can identify 13 of the high-risk HPVs associated with cervical cancer. Performed by collecting cervical cells and sending them to a lab for analysis, this test looks for viral DNA (deoxyribonucleic acid).⁶

If your Pap test shows a definite precancerous abnormality, an HPV tests isn't necessary, as virtually all such changes are caused by HPV.⁷

What should I do if I have HPV?

Sometimes a person may be too scared or embarrassed to ask for information or help. But, keep in mind most STIs are easy to treat. Early treatment of STIs is important. The quicker you seek treatment, the less likely the STI will cause you severe harm. And the sooner you tell your sex partners about having an STI, the less likely they are to spread the disease to others (because they can get treated). Doctors, local health departments, and STI and family planning clinics have information about STIs. The American Social Health Association (ASHA) has free information and keeps lists of clinics and doctors who provide treatment for STIs. Call ASHA at (800) 227-8922. You can get information from the phone line without leaving your name.⁸

If you have HPV:

• Get it treated right away. Studies suggest that having an STI increases your risk for getting infected with HIV, the virus that causes AIDS.
• Follow your health care provider's orders and finish all the medicine that you are given. Even if the symptoms go away, you still need to finish all of the medicine.
• Avoid having any sexual activity while you are being treated for HPV.
• Be sure to tell your sexual partners, so they can be tested.
• Remember that HPV is a lifelong disease. Even though you may have long periods with no symptoms, you can still pass the virus to another person.
Talk with your health care provider (and see the above question) about what you can do to lower your risk for both recurrences of HPV, and for passing the virus to another person.

Is there a cure for HPV?

Although the lesions and warts caused by human papilloma viruses can be treated, there is currently no medical cure for HPV. Lesions are commonly treated using a method called cryosurgery, in which the tissue is destroyed by freezing. Loop electrosurgical excision procedure, or LEEP, removes the tissue using a hot wire loop. Similar treatments may be used for external genital warts.

Researchers are studying ways to prevent HPV infection and its associated disease. They have also created vaccines to protect against HPV. The vaccines Cervarix and Gardasil have been approved for use in Canada, the United States, and Australia and have been studied in clinical trials for the prevention of cervical cancer. These vaccines target high-risk HPV types 16 and 18, which account for approximately 70 percent of cervical cancer cases worldwide, and low-risk HPV types 6 and 11, which cause approximately 90% of anogenital warts; they do not protect against any other types of low- or high-risk types of HPV. Studies have shown that these vaccines provide good protection against HPV for five years of follow-up; they are ongoing to determine if further immunization or a booster dose is necessary for vaccinated females to have continued protection.

Ideally, the vaccine should be administered to females before they become sexually active in order to ensure maximum benefit. The vaccine is not recommended for pregnant women, females under nine years of age, or males.

Also be sure to read…

Cervical cancer
How can I avoid or prevent cervical cancer?
Diagnostic tests for women with abnormal cervical cytology results
Treating cervical cancer
Pap test
Chlamydia
Human papilloma virus (HPV)
Genital warts

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1. Human Papillomavirus and Genital Warts. Office on Women's Health. U.S. Department of Health and Human Services.
2. Human Papillomaviruses and Cancer: Questions and Answers. National Cancer Institute.
3. Human Papillomaviruses and Cancer: Questions and Answers. National Cancer Institute.
4. Human Papillomaviruses and Cancer: Questions and Answers. National Cancer Institute.
5. Human Papillomavirus and Genital Warts. Office on Women's Health. U.S. Department of Health and Human Services.
6. Human Papillomaviruses and Cancer: Questions and Answers. National Cancer Institute.
7. Frequently Asked Questions. National Cervical Cancer Public Education Campaign: You Need to Know. Gynecologic Cancer Foundation.
8. Human Papillomavirus and Genital Warts. Office on Women's Health. U.S. Department of Health and Human Services.
9. Human Papillomaviruses and Cancer: Questions and Answers. National Cancer Institute.