Human papillomavirus--lessons from history and challenges for the future.

Human papillomavirus (HPV) is the most common sexually transmitted infection, and HPV-associated cervical cancer is a significant cause of morbidity and mortality worldwide. Recent advances in molecular biology have facilitated testing for HPV infection. Over the last decade, national and international cervical cancer screening programs have added HPV testing to their guidelines. The use of HPV prophylactic and therapeutic immunization may expand the need for systematic HPV testing to help define eligible subgroups for intervention. Given the worldwide variation in HPV subtype prevalence, basic Pap testing will continue to play an important role in cervical cancer screening, and methods to improve Pap smear sensitivity may help to improve screening in the future. This review focuses on the genetics and cellular biology of HPV infection, the natural history and prevalence of HPV infections, cervical cancer screening around the world and in Canada in particular, and evolving research to improve screening methods.