Human Papillomavirus (HPV)

The Issue

HPV is estimated to be one of the most common sexually transmitted infections (STIs) in Canada and around the world. Many types of HPV have been identified, with some leading to cancer and others to ano-genital warts. Fortunately, there is now a vaccine available to help prevent infection with some types of HPV and offers protection against HPV types responsible for approximately 70% of cervical cancers.

Background

The different types of HPV can lead to different health outcomes. Some types can infect the ano-genital area, while others infect areas such as the hands and feet. The types that infect the ano-genital area can be transmitted during vaginal, oral or anal sex or during intimate skin-to-skin contact with someone who is infected.

HPV causes almost all cases of cervical cancer. It has also been linked to other cancers such as vulvar, penile and anal cancer, but these links are still being investigated.

Some HPV types, like those that cause ano-genital warts, are considered ‘low risk’ because they are rarely associated with cancer. Other HPV types are considered ‘high risk’ because they are linked to cancer. It is possible to have more than one type of HPV at a time.

It is estimated that as many as 75 % of sexually active men and women will have at least one HPV infection in their lifetime. There is no known cure for HPV infections, but many people who have healthy immune systems will eventually clear the infection from their bodies. Although a high percentage of sexually active people will be infected with HPV, only a small proportion of these would potentially go on to develop cancer.

Many of the symptoms of HPV infection, such as warts, can be treated. However, some infections do persist and the symptoms may recur. Practising safer sex by using condoms and reducing the number of partners you have can help to reduce your chances of getting an HPV infection or another STI.

Routine Pap (Papanicolaou) testing is an important screening tool for cervical cancer as there is no precise way to determine in which people HPV infections will persist and lead to cancer.

Symptoms of HPV

Ano-genital warts, (also called Condylomata) are one symptom of HPV infection. They may look like a small cauliflower or they may be flat. In women, the warts may appear on the vulva, cervix, thigh, anus, rectum or in the vagina or urethra. In men, they may appear on the penis, scrotum, thigh, anus, rectum or in the urethra.

During pregnancy the number and size of warts can increase, but they usually decrease after delivery.

HPV is often a 'silent' infection, because many people with HPV will have no obvious signs of infection. Sometimes warts can be present but may not be visible if they are inside your body or if they are on the skin but are too small to be seen.

For women, the cervix is a common place for HPV infection. This infection can be either active or inactive. With an inactive infection, the cells appear normal under a microscope and the woman may never know she was infected.

However, with an active infection, changes can be seen in the cervical cells under a microscope during a Pap test. An active infection can follow one of two courses:

• The abnormal cells become normal again and the infection becomes inactive or is cleared from your body by your immune system. However, there is always the chance that an inactive infection can become active again, for reasons that aren't clearly understood.
• The abnormal cells slowly progress to cervical cancer.

Regular Pap testing can help to identify changes in the cells of the cervix, allowing them to be treated or followed more closely. If these changes are not identified early, there is a possibility that they can progress to cancer.

HPV testing is available in Canada, but access varies across the country. HPV testing may not be covered under provincial and territorial health programs, which means you may have to pay for it. It is not part of a regular check-up or Pap test. HPV testing, where recommended and available, is currently used along with Pap tests to decide if a woman is at risk of developing pre-cancerous and cancerous changes in the cervix.

The Health Risks of HPV

Almost all cervical cancers are caused by HPV. HPV is also linked to other cancers in both men and women, such as cancer of the penis, anus, vagina or vulva. More research is needed to clearly define the extent of these linkages.

Ano-genital warts are a significant burden and can lead to physical, emotional and social problems for those who are affected. They can be treated by applying prescribed medication to the warts. Some applications need to be done in a doctor's office and others you can apply yourself at home. Several treatments are usually needed to be effective. In some cases, your doctor may use other methods, such as cryotherapy (cold), an electric current, a laser or remove the warts by cutting them off. However, the removal of visible warts does not always eliminate HPV infection. Sometimes the warts can come back after treatment.

HPV does not appear to affect a woman's ability to become pregnant. It is not certain what effect HPV can have on the baby. The baby may be at risk of getting an HPV infection in the throat, but this is considered a rare occurrence. A C-section delivery is not routinely recommended, unless there is a significant obstruction or other risks.

Protecting Against HPV through immunization

A vaccine, called Gardasil™, which prevents certain types of HPV has been approved for use in Canada. The vaccine protects against infection with two high risk types of HPV (16 and 18) and two low risk types (6 and 11). HPV types 16 and 18 cause approximately 70% of cervical cancers. HPV types 6 and 11 cause approximately 90% of ano-genital warts. The HPV vaccine appears to be very effective in preventing HPV infection and changes in the cell of the cervix related to these types of HPV.

The vaccine does not protect against any of the other low or high risk types of HPV. However, if you are infected with one of the four HPV types in the vaccine, the vaccine will still protect against the other types in the vaccine. For example, if you are infected with HPV type 6, the vaccine will still protect you from types 11, 16, and 18.

The HPV vaccine will not have an impact on an existing infection or any consequences of infection, such as ano-genital warts and cancerous or pre-cancerous changes that you may already have. Talk to your doctor for more information.

The vaccine has been approved for use in females ages 9 to 26, and involves three doses over the course of six months. Pregnant women should avoid the vaccine. The potential effects on the infant of a woman being vaccinated while breastfeeding are unknown. Talk to your doctor for more information.

The vaccine has been shown to be safe within studies, with participants reporting few side effects. The most common side effect was a brief soreness at the site of injection. The vaccine does not contain the virus. It contains only particles from part of the virus, so you cannot be infected by the virus from the vaccine. Also, the vaccine does not contain any preservative or antibiotics, including thimerosal or mercury.

Recent studies indicate good protection against HPV types in the vaccine for five years of follow-up. Studies are ongoing to determine if further immunization is needed for vaccinated women to have continued protection. Studies are also currently being done in males.

Since the HPV vaccine does not protect against all types of HPV, you are still at risk for infection with other types of HPV, even if you are vaccinated. Therefore, it is important that vaccinated girls and women continue to have regular Pap tests.

Use of Gardasil™ is recommended by the National Advisory Committee on Immunization for:

• Females between 9 and 13 years of age, before the onset of sexual intercourse;
• Females between the ages of 14 and 26 years of age, even if they are already sexually active, have had previous pap abnormalities, or have had a previous HPV infection.

Use of Gardasil™ is not recommended by NACI for:

• Females under 9 years of age;
• Males;
• Pregnant women

Minimizing Your Risk

These measures can help protect you against HPV and its consequences.

• Anyone who has had sex is at risk for HPV. Since not all infections have symptoms or noticeable symptoms, you often cannot tell if you are infected.
• If you are a woman, see your doctor regularly for a Pap test and/or a HPV DNA test, where recommended and available - even if you have been vaccinated for HPV.
• Learn about STIs including their signs, symptoms, consequences and methods of transmission. Learn about safer sex methods and use them consistently.
• Make informed decisions about your sexual health. Talk to your partner(s) about their sexually transmitted infection (STI) status and the use of protection. Remember that the previous sexual behaviours of your partner are also a risk for you, especially if they have had multiple partners.
• The use of latex and polyurethane condoms may reduce your risk of getting HPV, as well as preventing other STIs. However, remember that the areas of skin not covered by the condom are not protected.
• If you are a female or have young female children between 9 to 26 years of age, consider immunization with the HPV vaccine.
• If you have had multiple sexual partners, talk to your doctor about HPV and other STIs which you may have been exposed to.

Government of Canada's Role

Along with health, education and other partners, the Public Health Agency promotes the physical and psycho-social well being of Canadians through sexual health promotion activities and cancer control strategies. Activities include:

• the development of national guidelines, including vaccine recommendations
• publication of national consensus statements and policy recommendations
• development of surveillance initiatives and targeted research studies
• coordination of the dissemination and exchange of information.

The Public Health Agency supports efforts to prevent and control sexually transmitted infections and their complications, including cancer and infertility.

The National Advisory Committee on Immunization (NACI) provides recommendations on the use of vaccines and has published its statement on HPV vaccine.

Need More Info?

For more information on HPV, cervical cancer screening or vaccination talk to your doctor or visit your local public health clinic. To find a clinic, check your telephone book under ‘Sexual Health’ in the white pages or under ‘Health’ in the blue pages.

You can also find helpful information on HPV, other STIs and sexual health at the following Web sites.

For more information on the HPV Vaccine, see the National Advisory Committee on Immunization site advisory. (PDF document)

For more information on HPV, see the Canadian Health Network and search for "HPV".

The Public Health Agency of Canada's Sexual Health and Sexually Transmitted Infections Web site.

STI Helpline

Canadian Cancer Society - The human papillomavirus (HPV) and cervical cancer

For information on STIs directed at youth, adults, parents, teachers and health professionals go to the Society of Obstetricians and Gynaecologists of Canada's Sexuality and U Web site.
Telephone: (800) 561-2416 or (613)730-4192

For tips on safer sex practices go to:

The Condoms, Sexually transmitted infections, Safer Sex and You Web site.

It's Your Health - Condoms

For more information on common STIs and tips on prevention go to the College of Family Physicians of Canada's Web site.

For additional articles on health and safety issues go to the It's Your Health Web site.
You can also call toll free at 1-866-225-0709 or TTY at 1-800-267-1245*.

Updated: April 2007
Original: September 2004
© Her Majesty the Queen in Right of Canada, represented by the Minister of Health, 2007