HPV: The global burden

Human papillomavirus (HPV) has become synonymous with cervical cancer, but its actual footprint is much bigger, by James Mitchell Crow.

HPV comes in many forms

Credit: WHO/ICO INFORMATION CENTRE ON HPV AND CERVICAL CANCER

Tens of different papillomavirus types infect humans, but only a handful are harmful. Mapping HPV types by genus (see Figure 1) reveals that certain species often cause similar warts and lesions, with most of the HPV types that cause cancer coming from the same species. However, shared pathology doesn’t always indicate close family ties; HPV types 1, 2 and 4, which all cause common skin warts, are distant relations.

Figure 1

Bernard H-U et al. Virology 401, 70–79 (2010).

How HPV can lead to cancer

Although HPV infections are common, 90% of cervical infections are cleared within 2 years (see Figure 2). If infection persists, abnormal cells can begin to appear. Only if these cervical cells cross the basal membrane and spread into the tissues beneath does the condition become cervical cancer.

Figure 2

Infection rates and cancer cases

Cervical HPV infection rates vary around the world (see Figure 3), as does the number of infected women who go on to develop cervical cancer.

Figure 3

WHO/ICO INFORMATION CENTRE ON HPV AND CERVICAL CANCER; DE SANJOSE, S. ET AL. LANCET INFECT. DIS. 7 453–459 (2007).

HPV and cancer

Although the overwhelming majority of cancers caused by HPV infection are of the cervix, infection with the virus can also lead to cancers in other parts of the body.

Credit: Credit: PARKIN DM, BRAY F. VACCINE 24 (SUPPL 3):S11–S25 (2006).

The future of HPV screening

HPV tests are proving more effective than traditional cytology screens at catching early-stage infections that progress to high-risk lesions.

Credit: PARKIN DM, BRAY F. VACCINE. 2006;24 (SUPPL 3):S11–S25. J. DILLNER ET AL., BMJ 2008; 377: A1754, WHO/ICO INFORMATION CENTRE ON HPV AND CERVICAL CANCER. SANJOSE DE, S. LANCET INFECT. DIS. 7 453–459 (2007).

Credit: Bernard H-U et al. Virology 401, 70–79 (2010).

Credit: WHO/ICO INFORMATION CENTRE ON HPV AND CERVICAL CANCER; DE SANJOSE, S. ET AL. LANCET INFECT. DIS. 7 453–459 (2007).