HIV in Canada: A primer for service providers

Human Papillomavirus

Key Points

  • It is estimated that more than 70% of sexually active Canadians will have at least one infection with human papillomavirus in their life.
  • Consistent and correct condom use can reduce, but not eliminate, the risk of getting or transmitting human papillomavirus
  • A vaccine is available that prevents certain types of human papillomavirus.
  • The presence of human papillomavirus increases the risk of transmitting and acquiring HIV.
  • Certain types of human papillomavirus can lead to cervical, penile and anal cancer.

National incidence and prevalence data do not exist for human papillomavirus (HPV) as it is not a notifiable disease in Canada. However, it is estimated that more than 70% of all sexually active Canadians will have at least one HPV infection in their lifetime. The Society of Obstetricians and Gynaecologists of Canada estimates that 10–30% of the adult population has HPV.

There are over 100 strains of HPV. About 40% of HPV strains are transmitted sexually. Some of these strains can cause anogenital warts, some can lead to cancer (e.g., cervical, penile, anal or throat cancer) and others have no known effect.

Consistent and correct condom use can reduce, but not eliminate, the risk of getting or transmitting HPV. This is because a condom can only protect the area it covers so it is possible to become infected by an uncovered anogenital wart. Two vaccines for HPV have been approved for use in Canada: Gardasil (approved in 2006) and Cervarix (approved in 2010). Both vaccines provide protection against two HPV types that cause 70% of all cervical cancers. In addition, Gardasil protects against another two HPV types that cause 90% of all anogenital warts. Gardasil is approved for use in females aged 9 to 45 years and males aged 9 to 26 years; Cervarix is approved for use in females aged 10 to 25 years. There are universal vaccination programs for school-aged females in every Canadian province and territory.

In 2012, the National Advisory Committee on Immunization expanded its recommendations on HPV vaccination to include males aged 9 to 26 years and men who have sex with men. However, not all provinces and territories have expanded HPV vaccination programs to include males.

The vaccines have very high efficacy in preventing the types of HPV infection for which they are indicated, but vaccinated individuals may still become infected with the other types of HPV. Therefore, it is important to continue screening men and women for precancerous and cancerous changes (e.g., Pap tests and digital rectal exams).

Most people infected with HPV remain asymptomatic and the infection usually resolves within two years. However, the infection may persist for many years in some individuals. Some types of HPV may lead to the development of anogenital warts, which are usually painless and flesh coloured and may grow in clusters in more than one location. Anogenital warts may not always be visible as they can be located internally (e.g., inside the vagina or rectum). Other HPV types associated with precancerous and cancerous changes do not present any noticeable symptoms, so regular health check-ups are essential.

There is no cure for HPV, but HPV often clears on its own. If it does not, there are HPV treatment options. For now, HPV treatment focuses on the symptoms of the infection. Symptoms include genital warts associated with certain HPV types (which don’t generally lead to cancers) and the precancerous changes sometimes associated with other types of HPV.

The presence of HPV increases the risk of transmitting and acquiring HIV. Individuals living with HIV are at an increased risk of co-infection with HPV. People living with HIV also have an increased risk for HPV-related complications. Women living with HIV tend to have multiple types of HPV and are more likely to have persistent HPV-related conditions, cervical dysplasia (precancerous changes to the cervix), and are at higher risk for cancers of the cervix, vagina, anus, mouth and throat. HIV-positive men are at an increased risk of developing HPV-related cancers of the penis, anus, mouth and throat. Compared with average HIV-negative men, the relative risk of anal cancer is 37-fold higher in HIV-positive men who do not have sex with men and 60-fold higher in HIV-positive men who have sex with men.

Resource

HPV, cervical dysplasia and cancer – CATIE fact sheet

HPV, anal dysplasia and anal cancer – CATIE fact shee

Sources

  1. Public Health Agency of Canada. Human papillomavirus (HPV) prevention and HPV vaccines: questions and answers. Available from: http://www.phac-aspc.gc.ca/std-mts/hpv-vph/hpv-vph-vaccine-eng.php
  2. Public Health Agency of Canada. Human papillomavirus (HPV). Available from: http://www.phac-aspc.gc.ca/std-mts/hpv-vph/fact-faits-eng.php
  3. Hosein S. French study finds increased anal cancer risk despite ART. CATIE News. 2012. Available from: http://www.catie.ca/en/catienews/2012-12-19/french-study-finds-increased-anal-cancer-risk-despite-art
  4. Maclean D, Ollner A, Hosein SR. HPV, cervical dysplasia and cancer. CATIE Fact Sheet. 2009. Available from: http://www.catie.ca/en/fact-sheets/infections/hpv-cervical-dysplasia-and-cancer
  5. Houlihan CF et al. HPV infection and increased risk of HIV acquisition. A systematic review and meta-analysis. AIDS. 2012 Nov 13;26(17):2211–22.