Families around the country are affected by HPV, with 3,000 Canadians diagnosed with an HPV related cancer yearly [1]. Anyone who is sexually active can contract HPV through contact with someone who already has the virus. Most people are infected with HPV at some point in their lives, but may never know they have been infected. Like other viral infections such as a cold, HPV is usually cleared by the body's immune system without the need for other treatment. We do not know why a small percentage of people do not clear the infection, which can remain 'dormant' (inactive) in their bodies sometimes for many years [2] [3].

There are around 13 high-risk types of HPV that are responsible for almost all cervical cancers [4]. Within the high-risk group, types 16 and 18 are the most prevalent and responsible for 70% of cervical cancers [5]. HPV infection can cause changes to the cells of the cervix creating abnormalities. Once these abnormalities become severe they can develop into cancer, which is why cervical screening and HPV vaccination are important in helping to prevent cervical cancer.

There are two HPV vaccines which provide protection against the two high risk types of HPV (types 16 and 18) that cause 70% of all cervical cancers. One of the vaccines is also designed to provide protection against genital warts, which are caused by low risk types of HPV. Low risk types of HPV do not cause cervical cancer.


References

  1. Bruni L, Barrionuevo-Rosas L, Albero G, Aldea M, Serrano B, Valencia S, Brotons M, Mena M, Cosano R, Muñoz J, Bosch FX, de Sanjosé S, Castellsagué X. ICO Information Centre on HPV and Cancer (HPV Information Centre). Human Papillomavirus and Related Diseases in Canada. Summary Report 2014-12-18. 
  2. Muñoz N, et al., 2009. Persistence of HPV infection and risk of high-grade cervical intraepithelial neoplasia in a cohort of Colombian women. British Journal of Cancer 100, 1184–1190.
  3. Moscicki, AB, et al., 1998. The natural history of human papillomavirus infection as measured by repeat DNA testing in adolescent and young women. Journal of Pediatr 132, 277-284.
  4. Li N et al., 2011. Human papillomavirus type distribution in 30,848 invasive cervical cancers worldwide: variation by geographical region, histological type and year of publication. International Journal of Cancer 128, 927–935.
  5. Bosch, F.X., et al., Epidemiology and natural history of human papillomavirus infections and type-specific implications in cervical neoplasia. Vaccine, 2008. 26 (10), K1-16.

* image from WebMD  


"The HPV Vaccines and Preventing Cervical Cancer." Jo's Cervical Cancer Trust. N.p., 19 Aug. 2013. Web. 02 Mar. 2015.