What is HPV?
HPV consists of a group of more than 150 related viruses, each identified by a specific number referred to as HPV types. Some HPV types cause warts (papillomas) in infected person while others can lead to cancer in both men and women.
What is the prevalence of HPV?
HPV is the fourth most common cancer in women, causing an estimated 266,000 deaths and 528,000 new cases in 2012.
About 85% of infection is estimated to occur in the developing regions of the world and accounts for about 12% of all female cancers.
HPV types 16 and 18 account for about 70% of all cervical cancer cases globally.
What are the common target organs infected?
HPV is the most common viral infection of the reproductive track.
HPV infection can lead to cancer of the mouth, throat and anus in men and women.
Cervical, vaginal and vulvar cancers are seen in women while men have penile HPV cancer.
About 99.7% of all cervical cancer cases in women are linked to genital infection in women.
Rapid progression in oral HPV cancer has been recorded in places.
What are the primary target groups in a population?
Young adolescents aged between 9 and 14.
Cervical cancer has been identified as the most common among women under 35.
Young adult men and older men are also at risk of infection.
How is HPV transmitted?
HPV is distributed in the population during intimate skin-to-skin contact. The most prevalent is by vaginal, anal or oral sexual activities.
Most common transmission is by vaginal or anal sex. It has been claimed that nearly all men and women will get HPV at some point in life due to the ubiquitous nature of the virus.
What are the common symptoms?
HPV can still be transferred even when an infected person does not show any sign or symptoms.
Symptom can develop quickly after contracting the virus, within days, weeks, months or even years, making it difficult to investigate and establish the source of the virus.
HPV will disappear in most cases without any health issue. However, when persistence occurs, it may result in different types of genital warts and cancers. After infection by HPV, the cells of the cervix slowly undergo a series of pre-cancerous changes, which may eventually turn into a cervical cancer.
What treatment or control measures are available?
Target population screening and vaccinations are recommended preventative measure. There are vaccines for the most common HPV types that cause cervical cancers and other conditions like genital warts.
Three types of vaccines are listed:
- Bivalent – works by stimulating an immune response against two different antigen (e.g. HPV type 16 and 18
- Quadrivalent – works by stimulating an immune response against two different antigen
- and nonavalent vaccines – offer protection against 9 HPV viruses HPV types 6, 11, 16, 18, 31, 33, 45, 52, and 58, which account for the majority of the HPV types that cause cervical, vulvar, vaginal and anal cancers
The three groups of vaccines are highly efficacious against the most known virulent HPV types and prevent pre-cancerous lesions.
Vaccines protect against:
- Genital cancer
- Anal cancer
- Cancer of the head and neck.
Other medical treatment options are also available and aimed at the eradication of the infective viruses and / or stopping the development or progression of the cancerous cells.
Prevention remains a preferred HPV control and management strategy. Proactively attending healthcare screening centres is important for early identification and appropriate treatment measures.
References
- Centers for Disease Control and Prevention (CDC) – Human Papillomavirus – https://www.cdc.gov/hpv/parents/whatishpv.html
- Larson DA, Derkay CS. Epidemiology of recurrent respiratory papillomatosis. APMIS 2010; 118:450–454. 29
- UK NHA – Vaccinations – https://www.nhs.uk/conditions/vaccinations/hpv-human-papillomavirus-vaccine/#what-is-hpv
- Stanley MA. Epithelial cell responses to infection with human papillomavirus. Clin Microbiol Rev, 2012;25(2):215–222
- WHO guidelines for screening and treatment of precancerous lesions for cervical cancer prevention. World Health Organization, Geneva, 2013. Available at http://apps. who.int/iris/bitstream/10665/94830/1/9789241548694_eng.pdf, accessed February 2017. 33
- WHO guidance note. Comprehensive cervical cancer prevention and control: a healthier future for girls and women. World Health Organization, Geneva, 2013. Available at http://apps.who.int/iris/bitstream/10665/78128/3/9789241505147_ eng.pdf?ua=1, accessed February 2017. 34 WHO guidelines: use of cryotherapy for cervical intraepithelial neoplasia.
- World Health Organization, Geneva, 2011. Available at http://whqlibdoc.who.int/publications/2011/9789241502856_eng.pdf?ua=, accessed February 2017
- World Health Organization, Geneva, HPV Vaccine Introduction Clearing House – https://www.who.int/immunization/hpv/en/
- WHO HPV Vaccines and Safety – https://www.who.int/immunization/hpv/vaccines/en/
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